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Sample records for pulse guide par

  1. Guiding of relativistic laser pulses by preformed plasmachannels

    SciTech Connect

    Geddes, C.G.R.; Toth, Cs.; van Tilborg, J.; Esarey, E.; Schroeder, C.B.; Cary, J.; Leemans, W.P.

    2004-12-10

    Guiding of relativistically intense (>1018 W/cm2) laser pulses over more than 10 diffraction lengths has been demonstrated using plasma channels formed by hydrodynamic shock. Pulses up to twice the self guiding threshold power were guided without aberration by tuning the guide profile. Transmitted spectra and mode images showed the pulse remained in the channel over the entire length. Experiments varying guided mode power and simulations show a large plasma wave was driven.Operating just below the trapping threshold produces a dark current free structure suitable for controlled injection.

  2. Guiding chemical pulses through geometry: Y junctions.

    PubMed

    Qiao, L; Kevrekidis, I G; Punckt, C; Rotermund, H H

    2006-03-01

    We study computationally and experimentally the propagation of chemical pulses in complex geometries. The reaction of interest, CO oxidation, takes place on single crystal Pt(110) surfaces that are microlithographically patterned; they are also addressable through a focused laser beam, manipulated through galvanometer mirrors, capable of locally altering the crystal temperature and thus affecting pulse propagation. We focus on sudden changes in the domain shape (corners in a Y-junction geometry) that can affect the pulse dynamics; we also show how brief, localized temperature perturbations can be used to control reactive pulse propagation. The computational results are corroborated through experimental studies in which the pulses are visualized using reflection anisotropy microscopy. PMID:16605643

  3. Optical guiding of terawatt laser pulses in the plasma waveguide

    NASA Astrophysics Data System (ADS)

    Alexeev, I.; Fan, J.; Kim, K. Y.; Nikitin, S.; Milchberg, H. M.

    1999-11-01

    We report coupling and guiding of pulses of peak power 0.5 TW in 1.5 cm long preformed plasma waveguides generated in a high repetition rate argon gas jet. Greater than 50 percent coupling was measured in the injection of 50 mJ, 100 fs pulses, giving guided intensities up to 10^17 W/cm^2. For short delays between waveguide generation and pulse injection, refraction-induced pulse shortening occurred, with this effect reduced either by increasing the delay between waveguide generation and injection or by injecting a prepulse into the waveguide. We will also describe recent experiments which attempt to reduce the avalanche ionization threshold for the gases in which the waveguide is generated. This work is supported by the US Department of Energy (DEF G0297 ER 41039) and the National Science Foundation (PHY-9515509).

  4. Ultrasound-guided Pulsed Radiofrequency of the Third Occipital Nerve

    PubMed Central

    Kim, Eung Don; Kim, Young Hoon; Park, Chong Min; Kwak, Jung Ah

    2013-01-01

    A C2-3 zygapophygeal joint is a major source of cervicogenic headache. Radiofrequency (RF) neurotomy is preformed widely for zygapophygeal joint pain. Conventional RF denervation technique is generally performed under fluoroscopic control. Recently, ultrasound-guided radiofrequency on zygapophygeal joint has emerged as an alternative method. We report our experiences of two successful ultrasound-guided pulsed radiofrequencies on 39-year-old and 42-year-old males, who complained occipital headache and posterior neck pain. PMID:23614084

  5. User guide for the PULSE program

    USGS Publications Warehouse

    Rutledge, A.T.

    2002-01-01

    This manual describes the use of the PULSE computer program for analysis of streamflow records. The specific instructions included here and the computer files that accompany this manual require streamflow data in a format that can be obtained from U.S. Geological Survey (USGS) sites on the World Wide Web. The program is compiled to run on a personal computer that uses a Microsoft Windows-based operating system. This manual provides instructions for use of Microsoft Excel for plotting hydrographs, though users may choose to use other software for plotting. The program calculates a hydrograph of ground-water discharge to a stream on the basis of user-specified recharge to the water table. Two different formulations allow recharge to be treated as instantaneous quantities or as gradual rates. The process of ground-water evapotranspiration can be approximated as a negative gradual recharge. The PULSE program is intended for analyzing a ground-water-flow system that is characterized by diffuse areal recharge to the water table and ground-water discharge to a stream. Program use can be appropriate if all or most ground water in the basin discharges to the stream and if a streamflow-gaging station at the downstream end of the basin measures all or most outflow. Ground-water pumpage and the regulation and diversion of streamflow should be negligible. More information about the application of the method is included in Rutledge, 1997, pages 2-3. The program can be used in conjunction with ground-water-level data. If a well is open to the surficial aquifer, observed water-level rises in the well can be used to evaluate the timing of recharge. Such evaluation is most effective if there are numerous water-level observation wells in the basin. Water levels in observation wells can also be used to evaluate the rate of ground-water discharge estimated by the PULSE program. The results of such an evaluation may be problematic, however, because the relation between ground

  6. Near-infrared pulsed light to guide prostate biopsy

    NASA Astrophysics Data System (ADS)

    Boutet, J.; Debourdeau, M.; Laidevant, A.; Hervé, L.; Allié, C.; Vray, D.; Dinten, J.-M.

    2011-03-01

    The protocol for prostate cancer diagnosis, currently based on ultrasound guided biopsy, is limited by a lack of relevance. To improve this protocol, a new approach was proposed combining optical and ultrasound measurements to guide biopsy specifically to the tumors. Adding an optical measurement modality into an already existing ultrasound probe is challenging as the overall size of the system should not exceed a given dimension so as to fit the operative environment. Moreover, examination should not take more than 15 min to avoid any complication. A combined ultrasound and optical endorectal probe was designed to comply with the constraints of the sterilization protocols, the examination duration and required compactness. Therefore a totally innovative pulsed laser source has been designed to meet compactness requirements while providing accurate time-resolved measurements. A dedicated multi-channel photon counting system was optimized to decrease the examination duration. A fast reconstruction method based on the analysis of the intensity and time of flight of the detected photons has been associated to provide 3D localization of fluorescent dots almost immediately after acquisition. The bi-modal probe was capable of withstanding the sterilization procedures. The performance of the compact laser source has been shown at the same level as that of a standard laboratory Titane:Sapphire laser. The dedicated photon counting solution was capable of acquiring optical data in less than one minute. To evaluate the overall performance of the system in dealing with a realistic background signal, measurements and reconstructions were conducted on prostate mimicking phantom and in vivo.

  7. Design of pulse stretching cell for a sodium guide star optical system

    SciTech Connect

    Friedman, H.W.; Horton, J.A.; Kuklo, T.J.; Wong, N.J.

    1992-11-10

    A pulse stretcher has been designed for the LLNL sodium guide star experiment to lower the laser flux and avoid saturation effects. The optical design, mechanical layout and wavefront error analysis are presented.

  8. Guiding of intense laser pulse in uniform plasmas and preformed plasma channels

    SciTech Connect

    Wang Jingwei; Lei, A. L.; Wang Xin; Yu Wei; Yu, M. Y.; Senecha, V. K.; Wang, X. G.; Murakami, M.; Mima, K.

    2010-10-15

    Guiding of laser pulse in uniform plasmas and preformed plasma channels is investigated. The self-guiding mechanisms for these two cases are quite different. It is found that an intense laser pulse can be steadily self-guided in underdense plasmas with nearly a constant spot size if the self-consistently generated electron cavity has a sufficiently steep density gradient at the edge. In a preformed plasma channel, however, laser guiding is maintained mainly by the balance between the light diffraction and focusing. The latter is induced by the wall plasmas which greatly reduce the local dielectric constant. It is shown that the self-guiding of a laser pulse in uniform plasmas requires tens of terawatts power, but those that are in preformed channels can be realized with only a terawatt power.

  9. Guiding of high intensity ultrashort laser pulses in plasma channels produced with the dual laser pulse ignitor-heater technique

    SciTech Connect

    Volfbeyn, P.; Leemans, W.P.

    1998-07-01

    The authors present results of experimental investigations of laser guiding in plasma channels. A new technique for plasma channel creation, the Ignitor-Heater scheme is proposed and experimentally tested in hydrogen and nitrogen. It makes use of two laser pulses. The Ignitor, an ultrashort (< 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used subsequently to heat the existing spark via inverse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. The channel density was diagnosed with time resolved longitudinal interferometry. From these measurements the plasma temperature was inferred. The guiding properties of the channels were tested by injecting a > 5 {times} 10{sup 17} W/cm{sup 2}, 75 fs laser pulse.

  10. Self-Guiding of Ultrashort Relativistically Intense Laser Pulses to the Limit of Nonlinear Pump Depletion

    SciTech Connect

    Ralph, J. E.; Marsh, K. A.; Pak, A. E.; Lu, W.; Clayton, C. E.; Fang, F.; Joshi, C.; Tsung, F. S.; Mori, W. B.

    2009-01-22

    A study of self-guiding of ultra short, relativistically intense laser pulses is presented. Here, the laser pulse length is on the order of the nonlinear plasma wavelength and the normalized vector potential is greater than one. Self-guiding of ultrashort laser pulses over tens of Rayliegh lengths is possible when driving a highly nonlinear wake. In this case, self-guiding is limited by nonlinear pump depletion. Erosion of the pulse due to diffraction at the head of the laser pulse is minimized for spot sizes close to the blow-out radius. This is due to the slowing of the group velocity of the photons at the head of the laser pulse. Using an approximately 10 TW Ti:Sapphire laser with a pulse length of approximately 50 fs, experimental results are presented showing self-guiding over lengths exceeding 30 Rayliegh lengths in various length Helium gas jets. Fully explicit 3D PIC simulations supporting the experimental results are also presented.

  11. Self-guiding supercontinuum generation and damage in bulk materials induced by femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Sirutkaitis, Valdas; Gaizauskas, Eugenijus; Kudriashov, Viacheslav; Barkauskas, Martynas; Vaicaitis, Virgilijus; Grigonis, Rimantas; Piskarskas, Algis S.

    2003-05-01

    The dynamics of multiple pulse laser-induced damage in the form of cracking or nonlinear coloration in bulk materials (fused silica and borosilicate K8 glass) was studied under the irradiation by femtosecond pulses at 800 nm wavelength. A Ti:sapphire chirped pulse amplification system with ~130-fs pulse duration and ~1-mJ pulse energy at 1-kHz repetition rate was used in the experiment. Self-guided propagation of femtosecond pulses over greater than 1-cm lengths accompanied by intensive supercontinuum generation was observed and studied in an interaction geometry where the laser beam was focused in the middle of the thick (~4 cm) sample. The pulse energy value at which self-guided propagation and supercontinuum generation in fused silica was observed was ~60 times lower than the laser-induced damage threshold. The nonlinear coloration in K8 glass was present at pulse energy values which exceeded the threshold for self-guided propagation. Numerical simulations involving self-focusing, temporal dispersion and multiphoton absorption were found to be in good agreement with the experimental results.

  12. Ablation par laser pulse de revetements antierosion pour le domaine aeronautique

    NASA Astrophysics Data System (ADS)

    Ragusich, Alexis

    Erosion resistant coatings (ERCs) are frequently used to protect aircraft engine components against erosion, and therefore, to extend their lifetime and reduce maintenance cost. However, after many hours in service, certain areas of the coating will begin to deteriorate. Given that such components are generally very costly, it is desirable to replace only the coating instead of the part itself. This research is part of the MANU 4 project, supported by CRIAQ and NSERC, which aims to study the feasibility of stripping an erosion-resistant coating deposited on a titanium-based alloy with three different techniques: wet chemical etching, plasma etching and pulse laser ablation. This thesis focuses more specifically on the etching with a pulsed laser of a 20-mum thick TiAlN ERC deposited on a Ti-6Al-4V substrate. This work compares the suitability of two pulsed lasers: a femtosecond Ti:Sapphire laser emitting at 800 nm and a nanosecond KrF excimer laser centred at 248 nm. These two lasers were chosen since they are frequently used for micromachining applications and allow us to study the effect of the wavelength and pulse duration. Preliminary findings have allowed us to identify four most critical variables that influence the etch rate and the surface roughness: (i) beam size, (ii) laser power, (iii) stage speed, and (iv) step distance between scanned lines. For each laser, optimal etching conditions were obtained by varying a single parameter at a time. Final results show that the higher energy per pulse offered by the excimer laser allows one to increase by one order of magnitude the etch rate, but almost doubles, from 1 mum to 1.8 mum, the surface roughness, in comparison with results obtained with the Ti:Sapphire laser. Compared with other techniques, pulse laser ablation has the potential to offer very high selectivity. In this regard, plume emission spectroscopy was studied as an in situ technique to monitor the etching progress and determine the precise moment

  13. Guiding Criteria for Instrument Design at Long-pulse Neutron Sources

    NASA Astrophysics Data System (ADS)

    de Vicente, J. P.; Sordo, F.; Perlado, J. M.; Bermejo, F. J.; Fernandez-Alonso, F.

    2015-11-01

    We introduce and describe general criteria which characterize long-pulse neutron sources, with a view to guiding and facilitating subsequent instrument design and optimization for specific applications. The ensuing analysis shows that a long-pulse neutron source allows for the possibility of a wide range of flexible instrument concepts with variable resolution and dynamic range, tasks which invariably require the implementation of pulse-modulation techniques in the time domain, particularly for high-resolution applications. We also consider in some detail yet-to-be-tapped opportunities in the use of shorter proton pulses, characterised by a duration commensurate with typical moderation times at spallation sources.

  14. Improved laser triggering and guiding of meqavolt discharges with dual fs-ns pulses

    SciTech Connect

    Mejean, Guillaume; Ackermann, Roland; Kasparian, Jerome; Salmon, Estelle; Yu Jin; Wolf, Jean-Pierre; Rethmeier, Kay; Kalkner, Wilfried; Rohwetter, Philipp; Stelmaszczyk, Kamil; Woeste, Ludger

    2006-01-09

    We demonstrate that the capacity of ultrashort high-power laser pulses to trigger and guide high-voltage discharges can be significantly enhanced by a subsequent visible nanosecond laser pulse. The femtosecond pulse induces a bundle of filaments, which creates a conducting channel of low density and cold plasma connecting the electrodes. The subsequent laser pulse photodetaches electrons from O{sub 2}{sup -} ions in the electrode leader. The resulting electrons allow efficient heating by Joule effect in a retroaction loop, resulting in a 5% reduction of the breakdown voltage.

  15. Noise-like pulse in a gain-guided soliton fiber laser.

    PubMed

    Zhao, L M; Tang, D Y; Wu, J; Fu, X Q; Wen, S C

    2007-03-01

    We report on the operation of a passively mode-locked fiber ring laser made of purely positive dispersion fibers and mode-locked by using the nonlinear polarization rotation technique. It was experimentally found that apart from the gain-guided soliton operation the laser can also emit a kind of noise-like pulse. We show numerically that the noise-like pulse emission is caused by the peak power clamping effect of the laser cavity on the gain-guided soliton. PMID:19532451

  16. Noise-like pulse in a gain-guided soliton fiber laser

    NASA Astrophysics Data System (ADS)

    Zhao, L. M.; Tang, D. Y.; Wu, J.; Fu, X. Q.; Wen, S. C.

    2007-03-01

    We report on the operation of a passively mode-locked fiber ring laser made of purely positive dispersion fibers and mode-locked by using the nonlinear polarization rotation technique. It was experimentally found that apart from the gain-guided soliton operation the laser can also emit a kind of noise-like pulse. We show numerically that the noise-like pulse emission is caused by the peak power clamping effect of the laser cavity on the gain-guided soliton.

  17. Guiding out-migrating juvenile sea lamprey (Petromyzon marinus) with pulsed direct current

    USGS Publications Warehouse

    Johnson, Nicholas S.; Miehls, Scott M.

    2014-01-01

    Non-physical stimuli can deter or guide fish without affecting water flow or navigation and therefore have been investigated to improve fish passage at anthropogenic barriers and to control movement of invasive fish. Upstream fish migration can be blocked or guided without physical structure by electrifying the water, but directional downstream fish guidance with electricity has received little attention. We tested two non-uniform pulsed direct current electric systems, each having different electrode orientations (vertical versus horizontal), to determine their ability to guide out-migrating juvenile sea lamprey (Petromyzon marinus) and rainbow trout (Oncorhynchus mykiss). Both systems guided significantly more juvenile sea lamprey to a specific location in our experimental raceway when activated than when deactivated, but guidance efficiency decreased at the highest water velocities tested. At the electric field setting that effectively guided sea lamprey, rainbow trout were guided by the vertical electrode system, but most were blocked by the horizontal electrode system. Additional research should characterize the response of other species to non-uniform fields of pulsed DC and develop electrode configurations that guide fish over a range of water velocity.

  18. Practitioner's guide to laser pulse propagation models and simulation. Numerical implementation and practical usage of modern pulse propagation models

    NASA Astrophysics Data System (ADS)

    Couairon, A.; Brambilla, E.; Corti, T.; Majus, D.; de J. Ramírez-Góngora, O.; Kolesik, M.

    2011-11-01

    The purpose of this article is to provide practical introduction into numerical modeling of ultrashort optical pulses in extreme nonlinear regimes. The theoretic background section covers derivation of modern pulse propagation models starting from Maxwell's equations, and includes both envelope-based models and carrier-resolving propagation equations. We then continue with a detailed description of implementation in software of Nonlinear Envelope Equations as an example of a mixed approach which combines finite-difference and spectral techniques. Fully spectral numerical solution methods for the Unidirectional Pulse Propagation Equation are discussed next. The modeling part of this guide concludes with a brief introduction into efficient implementations of nonlinear medium responses. Finally, we include several worked-out simulation examples. These are mini-projects designed to highlight numerical and modeling issues, and to teach numerical-experiment practices. They are also meant to illustrate, first and foremost for a non-specialist, how tools discussed in this guide can be applied in practical numerical modeling.

  19. Refroidissement par évaporation d'un jet atomique guidé magnétiquement

    NASA Astrophysics Data System (ADS)

    Lahaye, T.

    2006-01-01

    This work deals with the experimental realization of an ultracold, magnetically guided atomic beam in the collisional regime. After a detailed description of the experimental setup developed for this purpose, a method to measure the beam temperature with radio-frequency spectroscopy is proposed theoretically and demonstrated experimentally. The variations in temperature, phase-space density and elastic collision rate of the beam during a cycle evaporation-rethermalization are calculated. Two-antenna radio-frequency evaporation experiments are then described. They allow one to demonstrate the occurrence of elastic collisions within the atomic beam. Two Hamiltonian methods allowing one to increase the elastic collision rate are then studied theoretically and investigated experimentally. The gain in the elastic collision rate obtained this way is then used in order to cool the beam by means of ten evaporation zones, thus increasing the beam's phase-space density by one order of magnitude. Finally, a detailed theoretical study of the evaporation kinetics shows that a ten-fold increase of the collision rate obtained so far should be sufficient to achieve quantum degeneracy. Cet ouvrage traite de la réalisation expérimentale d'un jet atomique ultrafroid guidé magnétiquement, dans le régime collisionnel. Après une description détaillée du dispositif expérimental développé à cette fin, une méthode de thermométrie par spectroscopie radio-fréquence est proposée et démontrée expérimentalement. Les variations de température, densité dans l'espace des phases et taux de collisions élastiques du jet au cours d'un cycle évaporation-rethermalisation sont calculées. Des expériences d'évaporation radio-fréquence à deux antennes sont ensuite présentées, qui permettent de prouver l'existence de collisions au sein du jet. Deux méthodes permettant d'augmenter le taux de collisions sont ensuite étudiées théoriquement, puis mises en œuvre. Le gain en taux

  20. Guiding of intense femtosecond laser pulses in fully ionized plasma channels

    NASA Astrophysics Data System (ADS)

    Downer, M. C.

    2002-11-01

    Plasma waveguides capable of guiding relativistically intense fs laser pulses without optical distortion are essential to developing GeV-scale laser wakefield accelerators, coherent short-wavelength sources and lenses for fourth-generation x-ray sources. Various approaches to guiding terawatt pulses through preformed plasma fibers inside gas-filled solid capillaries [1], and in laser-generated cylindrical shock waves [2] will be compared. We report the first implementation of a laser-generated waveguide in a Helium plasma, which provides full ionization and minimization of ionization-induced distortions of the guided pulse up to relativistic guided intensity. 80 fs laser pulses were guided at near-relativistic intensity (0.2 x 10^18 W/cm^2) over 60 Rayleigh ranges (1.5 cm) with > 50% throughput, 20 Hz repetition rate and no detectable distortion of their spectrum or 16 micron-diameter TEM_00 mode structure [3]. Channels were generated by the method developed by Milchberg et al. [2], in which a filament of He gas (300-700 Torr) was ionized and heated by a powerful line-focused Nd:YAG laser pulse. To enable waveguide formation in Helium, the method was modified by slightly (0.1%) pre-ionizing the helium to seed inverse bremsstrahlung absorption, and by lengthening (100 to 400 ps) and strengthening (0.3 to 1 J) the channel-forming laser pulse. Recent femtosecond time-resolved pump-probe experiments inside the Helium channel will be reported. The issues involved, and current progress, in upgrading performance to fully relativistic guided intensity (10^18 W/cm^2) will be discussed. [1] Ehrlich et al., Phys. Rev. Lett. 77, 4186 (1996); Hosokai et al., Opt. Lett. 25, 10 (2000); Spence et al., Phys. Rev. E 63, 015401 (2001). [2] C. G. Durfee, III and H. M. Milchberg, Phys. Rev. Lett. 71, 2409 (1993); J. Fan, et al. Appl. Phys. Lett. 73, 3064 (1998). [3] E. W. Gaul et al., Appl. Phys. Lett. 77, 4112 (2000).

  1. Plasma Parameter of a Capillary Discharge-Produced Plasma Channel to Guide an Ultrashort Laser Pulse

    SciTech Connect

    Higashiguchi, Takeshi; Terauchi, Hiromitsu; Bai, Jin-xiang; Yugami, Noboru

    2009-01-22

    We have observed the optical guiding of a 100-fs laser pulse with the laser intensity in the range of 10{sup 16} W/cm{sup 2} using a 1.5-cm long capillary discharge-produced plasma channel for compact electron acceleration applications. The optical pulse propagation using the plasma channel is achieved with the electron densities of 10{sup 17}-10{sup 18} cm{sup -3} and the electron temperatures of 0.5-4 eV at a discharge time delay of around 150 ns and a discharge current of 500 A with a pulse duration of 100-150 ns. An energy spectrum of the accelerated electrons from a laser-plasma acceleration scheme showed a peak at 1.3 MeV with a maximum energy tail of 1.6 MeV.

  2. 3D CT-guided pulsed radiofrequency treatment for trigeminal neuralgia.

    PubMed

    Fang, Luo; Ying, Shen; Tao, Wang; Lan, Meng; Xiaotong, Yu; Nan, Ji

    2014-01-01

    Trigeminal neuralgia (TN) is a pain syndrome characterized by pain in the trigeminal area often accompanied by a brief facial spasm or tic. The purpose of our study was to investigate the efficacy and clinical utility of CT-guided pulsed radiofrequency (PRF) for treatment of TN. Patients who were diagnosed with severe TN between September 2010 and October 2010 at Beijing Tiantan Hospital were included. Pulsed radiofrequency treatment (PRFT) was employed to treat TN. To verify the accurate needle position, a thin-section cranial CT scan was performed by using a multidetector CT scanner. Three-dimensional reconstruction was performed to visualize the location of the needle and the foramen ovale. A total of 20 patients were included in the study. Seven patients (35%) had favorable outcome 1 year after the PRFT. The numeric rating scale in the 7 patients with good outcome was significantly lower than the 13 patients with bad outcome at 1 day, 1 week, and 2 weeks after the treatment. The remaining 13 patients had residual pain 2 weeks after the PRFT and had to receive radiofrequency thermocoagulation (RFTC). In conclusion, the results of our study demonstrate that CT-guided PRFT is not an effective method of pain treatment for idiopathic TN as compared with conventional RFTC. However, CT-guided PRFT is associated with less complication than RFTC. PMID:23433058

  3. Nonconsecutive Pars Interarticularis Defects.

    PubMed

    Elgafy, Hossein; Hart, Ryan C; Tanios, Mina

    2015-12-01

    Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Nonconsecutive spondylolysis involving the lumbar spine is rare. In contrast to single-level pars defects that respond well to conservative treatment, there is no consensus about the management of multiple-level pars fractures; a few reports indicated that conservative management is successful, and the majority acknowledged that surgery is often required. The current study presents a rare case of pars fracture involving nonconsecutive segments and discusses the management options. In this case report, we review the patient's history, clinical examination, radiologic findings, and management, as well as the relevant literature. An 18-year-old man presented to the clinic with worsening lower back pain related to nonconsecutive pars fractures at L2 and L5. After 6 months of conservative management, diagnostic computed tomography-guided pars block was used to localize the symptomatic level at L2, which was treated surgically; the L5 asymptomatic pars fracture did not require surgery. At the last follow-up 2 years after surgery, the patient was playing baseball and basketball, and denied any back pain. This article reports a case of rare nonconsecutive pars fractures. Conservative management for at least 6 months is recommended. Successful management depends on the choice of appropriate treatment for each level. Single-photon emission computed tomography scan, and computed tomography-guided pars block are valuable preoperative tools to identify the symptomatic level in such a case. PMID:26665257

  4. Ultrasound-guided greater occipital nerve blocks and pulsed radiofrequency ablation for diagnosis and treatment of occipital neuralgia.

    PubMed

    Vanderhoek, Matthew David; Hoang, Hieu T; Goff, Brandon

    2013-09-01

    Occipital neuralgia is a condition manifested by chronic occipital headaches and is thought to be caused by irritation or trauma to the greater occipital nerve (GON). Treatment for occipital neuralgia includes medications, nerve blocks, and pulsed radiofrequency ablation (PRFA). Landmark-guided GON blocks are the mainstay in both the diagnosis and treatment of occipital neuralgia. Ultrasound is being utilized more and more in the chronic pain clinic to guide needle advancement when performing procedures; however, there are no reports of ultrasound used to guide a diagnostic block or PRFA of the GON. We report two cases in which ultrasound was used to guide diagnostic greater occipital nerve blocks and greater occipital nerve pulsed radiofrequency ablation for treatment of occipital neuralgia. Two patients with occipital headaches are presented. In Case 1, ultrasound was used to guide diagnostic blocks of the greater occipital nerves. In Case 2, ultrasound was utilized to guide placement of radiofrequency probes for pulsed radiofrequency ablation of the greater occipital nerves. Both patients reported immediate, significant pain relief, with continued pain relief for several months. Further study is needed to examine any difference in outcomes or morbidity between the traditional landmark method versus ultrasound-guided blocks and pulsed radiofrequency ablation of the greater occipital nerves. PMID:24282778

  5. Design of pulsed guiding magnetic field for high power microwave generators

    SciTech Connect

    Ju, J.-C. Zhang, H.; Zhang, J.; Shu, T.; Zhong, H.-H.

    2014-09-15

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields.

  6. Design of pulsed guiding magnetic field for high power microwave generators.

    PubMed

    Ju, J-C; Zhang, H; Zhang, J; Shu, T; Zhong, H-H

    2014-09-01

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields. PMID:25273750

  7. Thermo-mechanical simulation of guided waves in pipes excited by laser pulses

    NASA Astrophysics Data System (ADS)

    Lim, Hyeong Uk; Hong, Jung-Wuk

    2013-04-01

    Ultrasonic guided waves have been widely utilized for the structural health monitoring (SHM) of structural components such as plates and pipes. In particular, the noncontact excitation of the pipe surfaces using laser pulses has shown several advantages in experiments by eliminating the bonding process of the dielectric patches on the curved surfaces and the complicated interpretation of the temperature effect on the bonding layers. However, the numerical simulation of the methodology requires thermo-mechanical coupling and large-scale computation. Therefore, the numerical efficiency of the spatial partitioning by deploying thermo-mechanical elements and mechanical elements is investigated. Then, the laser excitation on the surface is modeled in the form of heat flux, and the generated wave forms are observed. The formation and propagation of the guided waves are also represented numerically.

  8. Limitation on Pre-pulse Level for Cone-Guided Fast-Ignition ICF

    SciTech Connect

    MacPhee, A G; Akli, K U; Beg, F N; Chen, C D; Chen, H; Divol, L; Hey, D S; Freeman, R R; Henesian, M; Kemp, A J; Key, M H; Pape, S L; Link, A; Ma, T; Mackinnon, A J; Ovchinnikov, V M; Patel, P K; Phillips, T W; Stephens, R B; Tabak, M; Town, R; Van Woerkom, L D; Wei, M S; Wilks, S C

    2009-09-01

    The viability of fast-ignition (FI) inertial confinement fusion hinges on the efficient transfer of laser energy to the compressed fuel via multi-MeV electrons. Pre-formed plasma due to laser pre-pulse strongly influences ultra-intense laser plasma interactions and hot electron generation in the hollow cone of an FI target. We induced a prepulse and consequent preplasma in copper cone targets and measured the energy deposition zone of the main pulse by imaging the emitted K{sub {alpha}} radiation. An integrated simulation of radiation hydrodynamics for the pre-plasma and particle in cell for the main pulse interactions agree well with the measured deposition zones and provide an insight into the enrgy deposition mechanism and electron distribution. It was demonstrated that a under these conditions a 100mJ pre-pulse completely eliminates the forward going component of {approx}2-4MeV electrons. Consequences for cone-guided fast-ignition are discussed.

  9. Combination of fiber-guided pulsed erbium and holmium laser radiation for tissue ablation under water

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans; Frenz, Martin; Ith, Michael; Altermatt, Hans J.; Jansen, E. Duco; Weber, Heinz P.

    1996-07-01

    Because of the high absorption of near-infrared laser radiation in biological tissue, erbium lasers and holmium lasers emitting at 3 and 2 mu m, respectively, have been proven to have optimal qualities for cutting or welding and coagulating tissue. To combine the advantages of both wavelengths, we realized a multiwavelength laser system by simultaneously guiding erbium and holmium laser radiation by means of a single zirconium fluoride (ZrF4) fiber. Laser-induced channel formation in water and poly(acrylamide) gel was investigated by the use of a time-resolved flash-photography setup, while pressure transients were recorded simultaneously with a needle hydrophone. The shapes and depths of vapor channels produced in water and in a submerged gel after single erbium and after combination erbium-holmium radiation delivered by means of a 400- mu m ZrF4 fiber were measured. Transmission measurements were performed to determine the amount of pulse energy available for tissue ablation. The effects of laser wavelength and the delay time between pulses of different wavelengths on the photomechanical and photothermal responses of meniscal tissue were evaluated in vitro by the use of histology. It was observed that the use of a short (200- mu s, 100-mJ) holmium laser pulse as a prepulse to generate a vapor bubble through which the ablating erbium laser pulse can be transmitted (delay time, 100 mu s) increases the cutting depth in meniscus from 450 to 1120 mu m as compared with the depth following a single erbium pulse. The results indicate that a combination of erbium and holmium laser radiation precisely and efficiently cuts tissue under water with 20-50- mu m collateral tissue damage. wave, cavitation, channel formation, infrared-fiber-delivery system, tissue damage, cartilage.

  10. Application of MR-guided focused pulsed ultrasound for destroying clots in vitro using thrombolytic drugs

    NASA Astrophysics Data System (ADS)

    Hadjisavvas, V.; Ioannides, K.; Damianou, C.

    2011-09-01

    In this paper an MR-guided focused pulsed ultrasound system for the treatment of stroke using thrombolytic drugs in a model in vitro is presented. A single element spherically focused transducer of 5 cm diameter; focusing at 10 cm and operating at 0.5 MHz or 1 MHz was used. The transducer was mounted in an MR compatible robot. The artery was modelled using a silicone tube. Tissue was modelled using polyaclylimide gel. Coagulated blood was used to model thrombus. A thermocouple was placed in the thrombus in order to measure the thrombus temperature. The effect of power, beam, and frequency was investigated. The goal was to maintain a temperature increase of less than 1 °C during the application of pulse ultrasound (called safe temperature). With the application of ultrasound alone there was no notable destruction of the thrombus. With the combination of ultrasound and thrombolytic drugs destruction occurred after 60 mins of pulse exposure (PRF = 1 s, duty factor = 10%, and with thrombus placed at 1 cm deep in the tissue). This simple in vitro model was proven very successful for evaluating MRgFUS as a modality for treating stroke. In the future we plan to apply this treatment protocol in live animals and humans.

  11. Efficient excitation of a mesospheric sodium laser guide star by intermediate-duration pulses

    SciTech Connect

    Morris, J.R.

    1994-02-01

    Calculations of backscatter emission of meosopheric sodium atoms in a laser guide star that is excited by pulses ranging from 30-ns to 0.9-{mu}s duration are described. The efficient use of such pulses at saturating irradiance values is shown to require {approximately} 3 GHz of spectral broadening to provide access to the full absorption spectrum of the D{sub 2} line. The broadening is provided by frequency modulation. A set of density matrices was used to account for all 24 hyperfine states and inhomogeneous Doppler broadening. At the broadband (3-GHz) saturation irradiance of 4 W/cm{sup 2}, both linearly and circularly polarized laser beams are shown to produce emission rates exceeding 60% of the maximum possible rate-equation rate for the 0.9-{mu}s pulses. As expected, circular polarization produced more backscatter than did linear polarization, but the enhancement never exceeded 1/3 in the calculations that are reported. A brief estimate of state precession in the Earth`s magnetic field suggests that achieving even this enhancement will require that the time scale for optical pumping be held to less than 1 {mu}s, which will require the use of irradiances greater than 0.7 W/cm{sup 2} and spectral coverage of the full 3-GHz hyperfine-plus-Doppler absorption profile, at least until most of the population is pumped out of the F = 1 ground states. 46 refs., 24 figs., 5 tabs.

  12. Ultrasound-guided Pulsed Radiofrequency Lesioning of the Phrenic Nerve in a Patient with Intractable Hiccup

    PubMed Central

    Kang, Keum Nae; Park, In Kyung; Suh, Jeong Hun; Leem, Jeong Gill

    2010-01-01

    Persistent and intractable hiccups (with respective durations of more than 48 hours and 1 month) can result in depression, fatigue, impaired sleep, dehydration, weight loss, malnutrition, and aspiration syndromes. The conventional treatments for hiccups are either non-pharmacological, pharmacological or a nerve block treatment. Pulsed radiofrequency lesioning (PRFL) has been proposed for the modulation of the excited nervous system pathway of pain as a safe and nondestructive treatment method. As placement of the electrode in close proximity to the targeted nerve is very important for the success of PRFL, ultrasound appears to be well suited for this technique. A 74-year-old man suffering from intractable hiccups that had developed after a coronary artery bypass graft and had continued for 7 years was referred to our pain clinic. He had not been treated with conventional methods or medications. We performed PRFL of the phrenic nerve guided by ultrasound and the hiccups disappeared. PMID:20830266

  13. Blocking and guiding adult sea lamprey with pulsed direct current from vertical electrodes

    USGS Publications Warehouse

    Johnson, Nicholas S.; Thompson, Henry T.; Holbrook, Christopher M.; Tix, John A.

    2014-01-01

    Controlling the invasion front of aquatic nuisance species is of high importance to resource managers. We tested the hypothesis that adult sea lamprey (Petromyzon marinus), a destructive invasive species in the Laurentian Great Lakes, would exhibit behavioral avoidance to dual-frequency pulsed direct current generated by vertical electrodes and that the electric field would not injure or kill sea lamprey or non-target fish. Laboratory and in-stream experiments demonstrated that the electric field blocked sea lamprey migration and directed sea lamprey into traps. Rainbow trout (Oncorhynchus mykiss) and white sucker (Catostomus commersoni), species that migrate sympatrically with sea lamprey, avoided the electric field and had minimal injuries when subjected to it. Vertical electrodes are advantageous for fish guidance because (1) the electric field produced varies minimally with depth, (2) the electric field is not grounded, reducing power consumption to where portable and remote deployments powered by solar, wind, hydro, or a small generator are feasible, and (3) vertical electrodes can be quickly deployed without significant stream modification allowing rapid responses to new invasions. Similar dual-frequency pulsed direct current fields produced from vertical electrodes may be advantageous for blocking or trapping other invasive fish or for guiding valued fish around dams.

  14. Data Communications Using Guided Elastic Waves by Time Reversal Pulse Position Modulation: Experimental Study

    PubMed Central

    Jin, Yuanwei; Ying, Yujie; Zhao, Deshuang

    2013-01-01

    In this paper, we present and demonstrate a low complexity elastic wave signaling and reception method to achieve high data rate communication on dispersive solid elastic media, such as metal pipes, using piezoelectric transducers of PZT (lead zirconate titanate). Data communication is realized using pulse position modulation (PPM) as the signaling method and the elastic medium as the communication channel. The communication system first transmits a small number of training pulses to probe the dispersive medium. The time-reversed probe signals are then utilized as the information carrying waveforms. Rapid timing acquisition of transmitted waveforms for demodulation over elastic medium is made possible by exploring the reciprocity property of guided elastic waves. The experimental tests were conducted using a National Instrument PXI system for waveform excitation and data acquisition. Data telemetry bit rates of 10 kbps, 20 kbps, 50 kbps and 100 kbps with the average bit error rates of 0, 5.75 x 10-4, 1.09 x 10-2 and 5.01 x 10-2, respectively, out of a total of 40, 000 transmitted bits were obtained when transmitting at the center frequency of 250 kHz and a 500 kHz bandwidth on steel pipe specimens. To emphasize the influence of time reversal, no complex processing techniques, such as adaptive channel equalization or error correction coding, were employed. PMID:23881122

  15. Ultrasound-Guided Pulsed Radiofrequency for Carpal Tunnel Syndrome: A Single-Blinded Randomized Controlled Study

    PubMed Central

    2015-01-01

    Objective We assessed the therapeutic efficiency of ultrasound-guided pulsed radiofrequency (PRF) treatment of the median nerve in patients with carpal tunnel syndrome (CTS). Methods We conducted a prospective, randomized, controlled, single-blinded study. Forty-four patients with CTS were randomized into intervention or control groups. Patients in the intervention group were treated with PRF and night splint, and the control group was prescribed night splint alone. Primary outcome was the onset time of significant pain relief assessed using the visual analog scale (VAS), and secondary outcomes included evaluation of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) results, cross-sectional area (CSA) of the median nerve, sensory nerve conduction velocity (SNCV) of the median nerve, and finger pinch strength. All outcome measurements were performed at 1, 4, 8, and 12 weeks after treatment. Results Thirty-six patients completed the study. The onset time of pain relief in the intervention group was significantly shorter (median onset time of 2 days vs. 14 days; hazard ratio = 7.37; 95% CI, 3.04–17.87) compared to the control group (p < 0.001). Significant improvement in VAS and BCTQ scores (p < 0.05) was detected in the intervention group at all follow-up periods compared to the controls (except for the severity subscale of BCTQ at week 1). Ultrasound-guided PRF treatment resulted in a lower VAS score and stronger finger pinch compared to the control group over the entire study. Conclusions Our study shows that ultrasound-guided PRF serves as a better approach for pain relief in patients with CTS. Trial Registration ClinicalTrials.gov NCT02217293 PMID:26067628

  16. Pulse

    MedlinePlus

    Heart rate; Heart beat ... The pulse can be measured at areas where an artery passes close to the skin. These areas include the: ... side of the foot Wrist To measure the pulse at the wrist, place the index and middle ...

  17. Near-GeV acceleration of electrons by a nonlinear plasma wave driven by a self-guided laser pulse.

    PubMed

    Kneip, S; Nagel, S R; Martins, S F; Mangles, S P D; Bellei, C; Chekhlov, O; Clarke, R J; Delerue, N; Divall, E J; Doucas, G; Ertel, K; Fiuza, F; Fonseca, R; Foster, P; Hawkes, S J; Hooker, C J; Krushelnick, K; Mori, W B; Palmer, C A J; Phuoc, K Ta; Rajeev, P P; Schreiber, J; Streeter, M J V; Urner, D; Vieira, J; Silva, L O; Najmudin, Z

    2009-07-17

    The acceleration of electrons to approximately 0.8 GeV has been observed in a self-injecting laser wakefield accelerator driven at a plasma density of 5.5x10(18) cm(-3) by a 10 J, 55 fs, 800 nm laser pulse in the blowout regime. The laser pulse is found to be self-guided for 1 cm (>10zR), by measurement of a single filament containing >30% of the initial laser energy at this distance. Three-dimensional particle in cell simulations show that the intensity within the guided filament is amplified beyond its initial focused value to a normalized vector potential of a0>6, thus driving a highly nonlinear plasma wave. PMID:19659287

  18. Water quality changes in floodplain lakes due to the Amazon River flood pulse: Lago Grande de Curuaí (Pará).

    PubMed

    Affonso, A G; Barbosa, C; Novo, E M L M

    2011-08-01

    Assurance of water quality for human consumption is essential for public health policies. In the Amazon floodplain, the seasonal water level variation causes periodic flooding of marginal areas that are usually used for settlements, agriculture and livestock. Therefore, the exchange of materials between the terrestrial and aquatic ecosystem affects the proportion of suspended and dissolved components in water and its physical-chemical characteristics, and consequently the quality of the water used by local people. Following this approach, the aim of this study is to evaluate changes in water quality in Lago Grande de Curuaí floodplain, Óbidos, Pará in response to the flood pulse, during one hydrological year from 2003 to 2004, based on water use classes (according to National Water Agency 357/2005 resolution) using chlorophyll-a and dissolved oxygen concentration as parameters and the eutrophication index. Ordinary kriging was applied to interpolate chlorophyll-a and dissolved oxygen and to predict values at non sampled locations. Each location was then classified according to water use acceptable parameters and to Carlson Trophic State Index modified by Toledo to map lake water classes and trophic status. The result showed that Lago Grande de Curuaí floodplain is a supereutrophic system, with levels of dissolved oxygen and chlorophyll-a not suitable for human supply during the receding water phase. These areas are located near the riverine communities, which can cause health problems due to the presence of potentially toxic algae. Therefore, monitoring water quality in Amazon lakes is essential to ensure the availability has appropriate quality for human and animal supplies. PMID:21881783

  19. Pulse

    MedlinePlus

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

  20. Pulse evolution and plasma-wave phase velocity in channel-guided laser-plasma accelerators.

    PubMed

    Benedetti, C; Rossi, F; Schroeder, C B; Esarey, E; Leemans, W P

    2015-08-01

    The self-consistent laser evolution of an intense, short-pulse laser exciting a plasma wave and propagating in a preformed plasma channel is investigated, including the effects of pulse steepening and energy depletion. In the weakly relativistic laser intensity regime, analytical expressions for the laser energy depletion, pulse self-steepening rate, laser intensity centroid velocity, and phase velocity of the plasma wave are derived and validated numerically. PMID:26382537

  1. On-Sky Tests of a High-Power Pulsed Laser for Sodium Laser Guide Star Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Otarola, Angel; Hickson, Paul; Gagné, Ronald; Bo, Yong; Zuo, Junwei; Xie, Shiyong; Feng, Lu; Rochester, Simon; Budker, Dmitry; Shen, Shixia; Xue, Suijian; Min, Li; Wei, Kai; Boyer, Corinne; Ellerbroek, Brent; Hu, Jingyao; Peng, Qinjun; Xu, Zuyan

    2016-03-01

    We present results of on-sky tests performed in the summer of 2013 to characterize the performance of a prototype high-power pulsed laser for adaptive optics. The laser operates at a pulse repetition rate (PRR) of 600-800Hz, with a 6% duty cycle. Its coupling efficiency was found to be, in the best test case (using 18W of transmitted power), 231±14 photons s‑1 sr‑1 atom‑1 W‑1 m2 when circular polarization was employed and 167±17 photons s‑1 sr‑1 atom‑1 W‑1 m2 with linear polarization. No improvement was seen when D2b repumping was used, but this is likely due to the relatively large laser guide star (LGS) diameter, typically 10 arcsec or more, which resulted in low irradiance levels. Strong relaxation oscillations were present in the laser output, which have the effect of reducing the coupling efficiency. To better understand the results, a physical modeling was performed using the measured pulse profiles and parameters specific to these tests. The model results, for a 10 arcsec angular size LGS spot, agree well with the observations. When extrapolating the physical model for a sub-arcsecond angular size LGS (typical of what is needed for a successful astronomical guide star), the model predicts that this laser would have a coupling efficiency of 130 photons s‑1 sr‑1 atom‑1 W‑1 m2, using circular polarization and D2b repumping, for a LGS diameter of 0.6 arcsec Full Width at Half Maximum (FWHM), and free of relaxation oscillations in the 589 nm laser light.

  2. Photon Return On-Sky Test of Pulsed Sodium Laser Guide Star with D2b Repumping

    NASA Astrophysics Data System (ADS)

    Jin, Kai; Wei, Kai; Feng, Lu; Bo, Yong; Zuo, JunWei; Li, Min; Fu, HanChu; Dai, XiaoLin; Bian, Qi; Yao, Ji; Xu, Chang; Wang, ZhiChao; Peng, QingJun; Xue, XiangHui; Cheng, XueWu; Rao, ChangHui; Xu, ZuYan; Zhang, YuDong

    2015-08-01

    Sodium laser guide star (LGS) system has become one of the critical components in modern astronomical adaptive optics system (AOS), especially for the next-generation extremely large telescopes, such as the Thirty Meter Telescope and the European Extremely Large Telescope. Since the wavefront detection performance of AOS is directly related to the brightness of LGS, it is important for AOS to maximize its photon generation efficiency by all means. Sodium D2b line repumping is such a technique that can greatly increase the returned photons for either sodium continuous wave (CW) laser or pulsed laser. This technique has been studied theoretically and field tested with a 20 W CW laser by European Southern Observatory team. However, field test results of a 20 W class pulsed laser with D2b repumping have not been reported yet. In this paper, our latest field test results with theoretical comparison of D2b repumping with a 20 W quasi-continuous wave (QCW) pulsed laser will be presented. With a linearly polarized beam, approximate 40% photon return enhancement was achieved when 10% of laser power was detuned to D2b line, which agreed well with results from a rate equation-based Monte Carlo photon return simulation program. Both experiment and simulation results indicate that with a higher laser intensity projected at the sodium layer, the D2b repumping will be more effective.

  3. Ionization-induced blueshift of high-peak-power guided-wave ultrashort laser pulses in hollow-core photonic-crystal fibers

    SciTech Connect

    Fedotov, A. B.; Serebryannikov, E. E.; Zheltikov, A. M.

    2007-11-15

    Ionization-induced change in the refractive index of a gas is shown to give rise to a substantial spectral blueshift of megawatt light pulses transmitted through a gas-filled hollow photonic-crystal fiber (PCF). This effect suggests the ways of controlling not only the rate, but also the sign of the soliton frequency shift for high-peak-power ultrashort light pulses guided in hollow PCFs filled with Raman-active ionizing gases.

  4. Ultrasound-guided pulsed radiofrequency treatment of the pudendal nerve in chronic pelvic pain.

    PubMed

    Ozkan, D; Akkaya, T; Yildiz, S; Comert, A

    2016-02-01

    Chronic pelvic pain is a condition that can be caused by pudendal neuralgia, interstitial cystitis, piriformis syndrome and neuropathy of the ilioinguinal, iliohypogastric and genitofemoral nerves. Based on three case reports this article discusses the clinical effectiveness of pulsed high-frequency radiofrequency (PRF) treatment applied to the pudendal nerve under ultrasound guidance in medicinally treated patients with chronic pelvic pain. PMID:26811947

  5. Experimental observations and simulations on relativistic self-guiding of an ultra-intense laser pulse in underdense plasmas

    SciTech Connect

    Chiron, A.; Bonnaud, G.; Dulieu, A.; Miquel, J.L.; Malka, G.; Louis-Jacquet, M.; Mainfray, G.

    1996-04-01

    The experimental images of the sidescattered light from a plasma, created by the multiterawatt laser pulse propagating in a hydrogen gas jet, exhibit clear dependence on both gas jet pressure and laser power. Two- and three-dimensional simulations of wave propagation, in presence of the relativistic electron mass increase and the ponderomotive expel of electrons, have been performed to reproduce the Thomson radiation from the plasma electrons. They show electron cavitation induced by the beam focusing, self-focusing, self-guiding, smoothing of the beam nonuniformities and, at larger power, beam filamentation. A bremsstrahlung model with account of the ionization, heating, expansion, and recombination dynamics of the gas, provides the plasma emission background. Both Thomson emission and bremsstrahlung are required to recover the experimental emission patterns. Among the interpretations, a scenario of laser self-guiding over five Rayleigh lengths can be found for 10 TW laser power and 5{times}10{sup 18} cm{sup {minus}3} electron density, which surprisingly disappears at larger powers and densities. {copyright} {ital 1996 American Institute of Physics.}

  6. Management of pudendal neuralgia using ultrasound-guided pulsed radiofrequency: a report of two cases and discussion of pudendal nerve block techniques.

    PubMed

    Hong, Myong-Joo; Kim, Yeon-Dong; Park, Jeong-Ki; Hong, Hyon-Joo

    2016-04-01

    Pudendal neuralgia is characterized by chronic pain or discomfort in the area innervated by the pudendal nerve, with no obvious cause. A successful pudendal nerve block is crucial for the diagnosis of pudendal neuralgia. Blind or fluoroscopy-guided pudendal nerve blocks have been conventionally used for diagnosis and treatment; however, ultrasound-guided pudendal nerve blocks were also reported recently. With regard to the achievement of long-term effects, although pulsed radiofrequency performed under fluoroscopic guidance has been reported, that performed under ultrasound guidance is not well reported. This report describes two cases of pudendal neuralgia that were successfully managed using ultrasound-guided pulsed radiofrequency and presents a literature review of pudendal nerve block techniques. However, in the management of chronic neuropathic pain, physicians should keep in mind that the placebo effect related to invasive approaches must not be neglected. PMID:26699147

  7. Fluorescence imaging beyond the ballistic regime by ultrasound pulse guided digital phase conjugation.

    PubMed

    Si, Ke; Fiolka, Reto; Cui, Meng

    2012-10-01

    Fluorescence imaging has revolutionized biomedical research over the past three decades. Its high molecular specificity and unrivaled single molecule level sensitivity have enabled breakthroughs in a variety of research fields. For in vivo applications, its major limitation is the superficial imaging depth as random scattering in biological tissues causes exponential attenuation of the ballistic component of a light wave. Here we present fluorescence imaging beyond the ballistic regime by combining single cycle pulsed ultrasound modulation and digital optical phase conjugation. We demonstrate a near isotropic 3D localized sound-light interaction zone. With the exceptionally high optical gain provided by the digital optical phase conjugation system, we can deliver sufficient optical power to a focus inside highly scattering media for not only fluorescence imaging but also a variety of linear and nonlinear spectroscopy measurements. This technology paves the way for many important applications in both fundamental biology research and clinical studies. PMID:23241552

  8. Follow the yellow-orange rabbit: a CCD optimized for wavefront sensing a pulsed sodium laser guide star

    NASA Astrophysics Data System (ADS)

    Beletic, James W.

    2004-09-01

    Most large telescopes are now implementing sodium laser guide star (LGS) adaptive optics (AO) systems. Most of these systems plan to use the Shack-Hartmann approach for wavefront sensing. In these systems, the laser spots that are imaged in the Shack-Hartmann subapertures suffer spot elongation due to the 10 km extent of the sodium layer. The spot elongation extends radially from the projection point, and increases linearly with the distance the subaperture is separated from the laser. For 8-meter class telescopes with laser projection behind the secondary mirror, the spot elongation is ~1 arc sec at the edge of the pupil, and does not significantly affect the performance of the AO system. However, for the coming generation of extremely large telescopes, sodium LGS spot elongation will significantly degrade the quality of wavefront measurement. Attention should now be given to the development of technologies that can reduce or eliminate the spot elongation problem. The laser spot elongation can be greatly reduced by projecting the sodium laser in a series of short (1-3 µsec) pulses. The Lawrence Livermore National Laboratory (LLNL) has been funded to develop a pulsed fiber laser. In parallel, a new kind of wavefront sensor detector must be developed to properly sense the pulsed laser return. In this paper, we present our project that will develop a novel CCD which is optimized for sensing the return from a pulsed sodium LGS. Our CCD design uses custom pixel morphology that aligns the pixels of each subaperture with the radial extension of the LGS spot. This pixel geometry will allow each subaperture to follow the yellow-orange rabbit (i.e. the 589 nm laser pulse) as it traverses the sodium layer, providing optimal sampling of a limited number of detected photons. This CCD will attain photon-noise limited performance at high frame rates, using MOSFET amplifiers that exist today (2-3 electrons noise). However, we seek even lower noise amplifiers, and as part of

  9. MR-guided pulsed high intensity focused ultrasound enhancement of docetaxel combined with radiotherapy for prostate cancer treatment

    NASA Astrophysics Data System (ADS)

    Mu, Zhaomei; Ma, C.-M.; Chen, Xiaoming; Cvetkovic, Dusica; Pollack, Alan; Chen, Lili

    2012-01-01

    The purpose of this study is to evaluate the efficacy of the enhancement of docetaxel by pulsed focused ultrasound (pFUS) in combination with radiotherapy (RT) for treatment of prostate cancer in vivo. LNCaP cells were grown in the prostates of male nude mice. When the tumors reached a designated volume by MRI, tumor bearing mice were randomly divided into seven groups (n = 5): (1) pFUS alone; (2) RT alone; (3) docetaxel alone; (4) docetaxel + pFUS (5) docetaxel + RT (6) docetaxel + pFUS + RT, and (7) control. MR-guided pFUS treatment was performed using a focused ultrasound treatment system (InSightec ExAblate 2000) with a 1.5T GE MR scanner. Animals were treated once with pFUS, docetaxel, RT or their combinations. Docetaxel was given by i.v. injection at 5 mg kg-1 before pFUS. RT was given 2 Gy after pFUS. Animals were euthanized 4 weeks after treatment. Tumor volumes were measured on MRI at 1 and 4 weeks post-treatment. Results showed that triple combination therapies of docetaxel, pFUS and RT provided the most significant tumor growth inhibition among all groups, which may have potential for the treatment of prostate cancer due to an improved therapeutic ratio.

  10. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    NASA Astrophysics Data System (ADS)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  11. A simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Hadjisavvas, V.; Damianou, C.

    2011-09-01

    In this paper a simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound is presented. A single element spherically focused transducer of 5 cm diameter, focusing at 10 cm and operating at either 0.5 MHz or 1 MHz was considered. The power field was estimated using the KZK model. The temperature was estimated using the bioheat equation. The goal was to extract the acoustic parameters (power, pulse duration, duty factor and pulse repetition frequency) that maintain a temperature increase of less than 1 °C during the application of a pulse ultrasound protocol. It was found that the temperature change increases linearly with duty factor. The higher the power, the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. The higher the frequency the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. Finally, the deeper the target, the higher the duty factor needed to keep the temperature change to the safe limit of 1 °C. The simulation model was tested in brain tissue during the application of pulse ultrasound and the measured temperature was in close agreement with the simulated temperature. This simulation model is considered to be very useful tool for providing acoustic parameters (frequency, power, duty factor, pulse repetition frequency) during the application of pulsed ultrasound at various depths in tissue so that a safe temperature is maintained during the treatment. This model could be tested soon during stroke clinical trials.

  12. Note: Characterization of the plasma parameters of a capillary discharge-produced plasma channel waveguide to guide an intense laser pulse

    SciTech Connect

    Higashiguchi, Takeshi; Yugami, Noboru; Hikida, Masafumi; Terauchi, Hiromitsu; Bai Jinxiang; Kikuchi, Takashi; Tao Yezheng

    2010-04-15

    We demonstrated the production of an optical waveguide in a capillary discharge-produced plasma using a cylindrical capillary. Plasma parameters of its waveguide were characterized by use of both a Nomarski laser interferometer and a hydrogen plasma line spectrum. A space-averaged maximum temperature of 3.3 eV with electron densities of the order of 10{sup 17} cm{sup -3} was observed at a discharge time of 150 ns and a maximum discharge current of 400 A. An ultrashort, intense laser pulse was guided by use of this plasma channel.

  13. Pars Injuries in Athletes.

    PubMed

    Oren, Jonathan H; Gallina, Jason M

    2016-03-01

    Pars injuries are common causes of low back pain in adolescent athletes. Workup traditionally has included lumbar radiographs with oblique views and single-photon emission computed tomography (SPECT). However, recent literature has demonstrated the accuracy of MRI as a diagnostic modality. Acute injuries may be amenable to bracing with the goal of a healed lesion. Most cases of spondylolysis will result in asymptomatic non-union, though pars repair is an option for symptomatic pars defects without spondylolisthesis. PMID:26977552

  14. Guiding and focusing of fast electron beams produced by ultra-intense laser pulse using a double cone funnel target

    SciTech Connect

    Zhang, Wen-shuai; Cai, Hong-bo; Zhu, Shao-ping

    2015-10-15

    A novel double cone funnel target design aiming at efficiently guiding and focusing fast electron beams produced in high intensity (>10{sup 19 }W/cm{sup 2}) laser-solid interactions is investigated via two-dimensional particle-in-cell simulations. The forward-going fast electron beams are shown to be directed and focused to a smaller size in comparison with the incident laser spot size. This plasma funnel attached on the cone target guides and focuses electrons in a manner akin to the control of liquid by a plastic funnel. Such device has the potential to add substantial design flexibility and prevent inefficiencies for important applications such as fast ignition. Two reasons account for the collimation of fast electron beams. First, the sheath electric fields and quasistatic magnetic fields inside the vacuum gap of the double cone provide confinement of the fast electrons in the laser-plasma interaction region. Second, the interface magnetic fields inside the beam collimator further guide and focus the fast electrons during the transport. The application of this technique to cone-guided fast ignition is considered, and it is shown that it can enhance the laser energy deposition in the compressed fuel plasma by a factor of 2 in comparison with the single cone target case.

  15. Guiding and focusing of fast electron beams produced by ultra-intense laser pulse using a double cone funnel target

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-shuai; Cai, Hong-bo; Zhu, Shao-ping

    2015-10-01

    A novel double cone funnel target design aiming at efficiently guiding and focusing fast electron beams produced in high intensity (>1019 W/cm2) laser-solid interactions is investigated via two-dimensional particle-in-cell simulations. The forward-going fast electron beams are shown to be directed and focused to a smaller size in comparison with the incident laser spot size. This plasma funnel attached on the cone target guides and focuses electrons in a manner akin to the control of liquid by a plastic funnel. Such device has the potential to add substantial design flexibility and prevent inefficiencies for important applications such as fast ignition. Two reasons account for the collimation of fast electron beams. First, the sheath electric fields and quasistatic magnetic fields inside the vacuum gap of the double cone provide confinement of the fast electrons in the laser-plasma interaction region. Second, the interface magnetic fields inside the beam collimator further guide and focus the fast electrons during the transport. The application of this technique to cone-guided fast ignition is considered, and it is shown that it can enhance the laser energy deposition in the compressed fuel plasma by a factor of 2 in comparison with the single cone target case.

  16. Par Pond water balance

    SciTech Connect

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs.

  17. Multi-GeV electron beams from capillary discharge guided sub-petawatt class laser pulses in the self-trapping regime

    NASA Astrophysics Data System (ADS)

    Leemans, Wim

    2014-10-01

    Laser plasma accelerators (LPAs) can produce acceleration gradients on the order of tens to hundreds of GV/m, making them attractive as compact particle accelerators. During the past decade, quasi-monochromatic electron beams at the 1 GeV energy level have been produced using laser pulses at the 40-50 TW peak power level. With the availability of petawatt class lasers, beams up to 2 GeV have been produced from 7 cm long gas cells at UT Austin using 150 J laser pulses and at the 1 GeV level with tails extending to 3 GeV at the GIST facility in Korea. In this talk we present experimental results using the 1 Hz petawatt class BELLA laser at LBNL of the generation of multi-GeV electron beams with center energy up to 4.2 GeV, 6% rms energy spread, charge approximately 10 pC and an rms divergence around 0.3 mrad. The beams were produced from 9 cm long capillary discharge waveguide structure with a plasma density of ~ 7 ×1017cm-3 , powered by laser pulses with peak power up to 0.3 PW. Preformed plasma waveguides allow the use of lower laser power compared to unguided plasma structures to achieve the same beam energy. Detailed comparison between experiment and simulation indicates the importance of the near-field laser transverse mode quality on guiding and acceleration in the LPA. By tuning the plasma density, regimes were found where laser beams with a top hat near-field profile were guided well, and where high energy electron beams can be produced, with narrow divergence [ <0.8 mrad (FWHM)], and relatively small integrated energy spread (<10%). Provided that the slice energy spread and emittance are sufficiently low, electron beams with this energy could power x-ray free electron lasers. Future experiments will aim at increasing the beam energy to the 10 GeV level. Work supported by Office of Science, Office of HEP, US DOE Contract DE-AC02-05CH11231.

  18. uPAR

    PubMed Central

    Uhrin, Pavel; Breuss, Johannes M.

    2013-01-01

    Vascular endothelial growth factor (VEGF)-initiated angiogenesis requires both coordinated proteolytic degradation of extracellular matrix provided by the urokinase plasminogen activator/urokinase receptor (uPA/uPAR) system and regulation of cell-migration provided by integrin–matrix interaction. Previously we have shown that stimulation of pericellular proteolysis induced by VEGF occurs via the VEGF receptor-2 leading to redistribution of uPAR to focal adhesions at the leading edge of endothelial cells. In our recent work published in Cardiovascular Research, we investigated the mechanisms underlying the uPAR-dependent modulation of VEGF-induced endothelial migration. By applying a micropatterning technique we described that VEGF stimulation results in complex formation between uPAR and α5β1-integrin on the cell surface. The subsequent internalization of this complex, important for receptor redistribution, was demonstrated by flow-cytometry and immunohistochemistry. Targeting of the interaction site between uPAR and α5β1 impairs receptor internalization and leads to the inhibition of endothelial cell migration in vitro and in an angiogenesis model in vivo. This proof-of-principle that the interface of uPAR and α5β1-integrin may represent a promising site to therapeutically target tumor angiogenesis raises hope for the development of an anti-angiogenic approach that is limited to only the mobilizing effect of VEGF to endothelial cells, and does not interfere with the inarguably positive effect of VEGF as survival factor. PMID:23076213

  19. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.

    PubMed

    Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M

    2004-12-01

    Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation. PMID:15697544

  20. THE MEASURES PAR PROJECT

    NASA Astrophysics Data System (ADS)

    Frouin, R. J.; Franz, B.

    2009-12-01

    The solar energy available for photosynthesis, known as PAR, controls the growth of phytoplankton and, therefore, regulates the composition and evolution of marine ecosystems. Knowing the spatial and temporal distribution of PAR over the oceans is critical to understanding biogeochemical cycles of carbon, nutrients, and oxygen, and to address important climate and global change issues such as the fate of anthropogenic atmospheric carbon dioxide. In view of this, a 12-year time series of PAR at the ocean surface, starting in September 1997, is being produced by the NASA Ocean Biology Processing Group from SeaWiFS, MODIS-Terra, and MODIS-Aqua data. The product covers the global oceans, with a spatial resolution of about 9.3x9.3 km (equal area grid) and a temporal resolution of one day. PAR is computed as the difference between the 400-700 nm solar flux incident on the top of the atmosphere (known) and reflected back to space by the atmosphere and surface (derived from satellite radiance), taking into account atmospheric absorption (modeled). Knowledge of pixel composition is not required, eliminating the need for cloud screening and arbitrary assumptions about sub-pixel cloudiness. Combining data from satellite sensors with different equatorial crossing times accounts for the diurnal variability of clouds and, therefore, increases accuracy on a daily time scale. The processing system, including routine check of accuracy and control of quality, is designed to operate during the entire lifetime of SeaWiFS and MODIS, and to accommodate future sensors with ocean-color capabilities. Maps of daily, weekly, and monthly PAR obtained from individual sensors are presented, as well as merged products. Accuracy is quantified in comparisons with other satellite estimates, the National Centers for Environmental Prediction reanalysis product, and in-situ measurements from fixed buoys and platforms. The good statistical performance makes the satellite PAR product suitable for large

  1. MRI-Guided 3D Optimization Significantly Improves DVH Parameters of Pulsed-Dose-Rate Brachytherapy in Locally Advanced Cervical Cancer

    SciTech Connect

    Lindegaard, Jacob C. Tanderup, Kari; Nielsen, Soren Kynde; Haack, Soren; Gelineck, John

    2008-07-01

    Purpose: To compare dose-volume histogram parameters of standard Point A and magnetic resonance imaging-based three-dimensional optimized dose plans in 21 consecutive patients who underwent pulsed-dose-rate brachytherapy (PDR-BT) for locally advanced cervical cancer. Methods and Materials: All patients received external beam radiotherapy (elective target dose, 45 Gy in 25-30 fractions; tumor target dose, 50-60 Gy in 25-30 fractions). PDR-BT was applied with a tandem-ring applicator. Additional ring-guided titanium needles were used in 4 patients and a multichannel vaginal cylinder in 2 patients. Dose planning was done using 1.5 Tesla T{sub 1}-weighted and T{sub 2}-weighted paratransversal magnetic resonance imaging scans. T{sub 1}-weighted visible oil-containing tubes were used for applicator reconstruction. The prescribed standard dose for PDR-BT was 10 Gy (1 Gy/pulse, 1 pulse/h) for two to three fractions to reach a physical dose of 80 Gy to Point A. The total dose (external beam radiotherapy plus brachytherapy) was normalized to an equivalent dose in 2-Gy fractions using {alpha}/{beta} = 10 Gy for tumor, {alpha}/{beta} = 3 Gy for normal tissue, and a repair half-time of 1.5 h. The goal of optimization was dose received by 90% of the target volume (D{sub 90}) of {>=}85 Gy{sub {alpha}}{sub /{beta}}{sub 10} in the high-risk clinical target volume (cervix and remaining tumor at brachytherapy), but keeping the minimal dose to 2 cm{sup 3} of the bladder and rectum/sigmoid at <90 and <75 Gy{sub {alpha}}{sub /{beta}}{sub 3}, respectively. Results: Using three-dimensional optimization, all dose-volume histogram constraints were met in 16 of 21 patients compared with 3 of 21 patients with two-dimensional library plans (p < 0.001). Optimization increased the minimal target dose (D{sub 100}) of the high-risk clinical target volume (p < 0.007) and decreased the minimal dose to 2 cm{sup 3} for the sigmoid significantly (p = 0.03). For the high-risk clinical target volume, D

  2. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  3. Manual for the Use of the Pupil Activities Record--Revised (PAR-R).

    ERIC Educational Resources Information Center

    Ligon, Glynn; And Others

    A comprehensive guide for observers using the Pupil Activities Record--Revised (PAR-R), this manual covers procedures followed in systematic observation of a student's classroom activities for the period of one instructional day. The manual provides general information about the purpose and design of the PAR and explains the revisions, which were…

  4. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r

  5. Multi-scale photoacoustic remote sensing (PARS) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Haji Reza, Parsin; Bell, Kevan; Shi, W.; Zemp, Roger J.

    2016-03-01

    We introduce a novel multi-scale photoacoustic remote sensing (PARS) imaging system. Our system can provide optical resolution details for superficial structures as well as acoustic resolution for deep-tissue imaging down to 5 cm, in a non-contact setting. PARS system does not require any contact with the sample or ultrasound coupling medium. The optical resolution PARS (OR-OARS) system uses optically focused pulsed excitation with optical detection of photoacoustic signatures using a long-coherence interrogation beam co-focused and co-scanned with the excitation spot. In the OR-PARS initial pressures are sampled right at their subsurface origin where acoustic pressures are largest. The Acoustic resolution PARS (AR-PARS) picks up the surface oscillation of the tissue caused by generated photoacoustic signal using a modified version of Michelson interferometry. By taking advantage of 4-meters polarization maintaining single-mode fiber and a green fiber laser we have generated a multi-wavelength source using stimulated Raman scattering. Remote functional imaging using this multi-wavelength excitation source and PARS detection mechanism has been demonstrated. The oxygen saturation estimations are shown for both phantom and in vivo studies. Images of blood vessel structures for an In vivo chicken embryo model is demonstrated. The Phantom studies indicates ~3µm and ~300µm lateral resolution for OR-PARS and AR-PARS respectively. To the best of our knowledge this is the first dual modality non-contact optical and acoustic resolution system used for in vivo imaging.

  6. 180 mJ, long-pulse-duration, master-oscillator power amplifier with linewidth less than 25.6 kHz for laser guide stars.

    PubMed

    Wang, Chunhua; Zhang, Xiang; Ye, Zhibin; Liu, Chong; Chen, Jun

    2013-07-01

    A high-energy single-frequency hundred-microsecond long-pulse solid-state laser is demonstrated, which features an electro-optically modulated seed laser and two-stage double-passed pulse-pumped solid-state laser rod amplifier. Laser output with energy of 180 mJ, repetition rate of 50 Hz, and pulse width of 150 μs is achieved. The laser linewidth is measured to be less than 25.52 kHz by a fiber delay self-heterodyne method. In addition, a closed-loop controlling system is adopted to lock the center wavelength. No relaxation oscillation spikes appear in the pulse temporal profile, which is beneficial for further amplification. PMID:23842267

  7. CONTROL OF LASER RADIATION PARAMETERS. GENERATION OF ULTRASHORT PULSES: Mode locking in linear injection laser arrays with gain-guided waveguides

    NASA Astrophysics Data System (ADS)

    Nakwaski, W.

    1990-12-01

    The problem of mode locking in linear arrays of lasers with gain-guided waveguides is considered on the basis of a theoretical analysis of Basov, Belenov, and Letokhov for diffraction-coupled lasers and also using the Vaĭnshteĭn approximation for diffraction losses. A simple calculation procedure, enabling an easy determination of the maximum wavelength difference between adjacent elements of gain-guided arrays, is proposed.

  8. Protease-activated receptor (PAR)1, PAR2 and PAR4 expressions in esophageal squamous cell carcinoma

    PubMed Central

    LI, Si-Man; JIANG, Ping; XIANG, Yang; WANG, Wei-Wei; ZHU, Yue-Chun; FENG, Wei-Yang; LI, Shu-De; YU, Guo-Yu

    2014-01-01

    Here, we used reverse transcription-PCR (RT-PCR) and western blot to detect protease-activated receptor (PAR) 1, PAR 2 and PAR 4 expression in cancer tissues and cell lines of esophageal squamous cell carcinoma, and investigated the co-relationship between PAR expression and clinic-pathological data for esophageal cancer. The methylation of PAR4 gene promoter involved in esophageal carcinoma was also analyzed. By comparing the mRNA expressions of normal esophageal tissue and human esophageal epithelial cells (HEEpiC), we found that among the 28 cases of esophageal squamous cell carcinoma, PAR1 (60%) and PAR2 (71%) were elevated in 17 and 20 cases, respectively, and PAR4 (68%) expression was lowered in 19 cases. Whereas, in human esophageal squamous cells (TE-1 and TE-10), PAR1 and PAR2 expression was increased but PAR4 was decreased. Combined with clinical data, the expression of PAR1 in poorly differentiated (P=0.016) and middle and lower parts of the esophagus (P=0.016) was higher; expression of PAR4 in poorly differentiated carcinoma was lower (P=0.049). Regarding TE-1 and TE-10 protein expression, we found that in randomized esophageal carcinoma, PAR1 (P=0.027) and PAR2 (P=0.039) expressions were increased, but lowered for PAR4 (P=0.0001). In HEEpiC, TE-1, TE-10, esophageal and normal esophagus tissue samples (case No. 7), the frequency of methylation at the 19 CpG loci of PAR4 was 35.4%, 95.2%, 83.8%, 62.6% and 48.2%, respectively. Our results indicate that the expression of PAR1 and PAR2 in esophageal squamous cell carcinoma is increased but PAR4 is decreased. Hypermethylation of the promoter of the PAR4 gene may contribute to reduced expression of PAR4 in esophageal squamous cell carcinoma. PMID:25297082

  9. Precision guided antiaircraft munition

    DOEpatents

    Hirschfeld, Tomas B.

    1987-01-01

    A small diameter, 20 mm to 50 mm, guided projectile is used in antiaircraft defense. A pulsing laser designator illuminates the target aircraft. Energy reflected from the aircraft is received by the guided projectile. The guided projectile is fired from a standard weapon but the spining caused by the riflings are removed before active tracking and guidance occurs. The received energy is focused by immersion optics onto a bridge cell. AC coupling and gating removes background and allows steering signals to move extended vanes by means of piezoelectric actuators in the rear of the guided projectile.

  10. Par Pond vegetation status 1996

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.

  11. Immunopathogenic Background of Pars Planitis.

    PubMed

    Przeździecka-Dołyk, Joanna; Węgrzyn, Agnieszka; Turno-Kręcicka, Anna; Misiuk-Hojło, Marta

    2016-04-01

    Pars planitis is defined as an intermediate uveitis of unknown background of systemic disease with characteristic formations such as vitreous snowballs, snowbanks and changes in peripheral retina. The incidence of pars planitis varies 2.4-15.4 % of the uveitis patients. The pathogenesis of the disease is to be determined in future. Clinical and histopathological findings suggest an autoimmune etiology, most likely as a reaction to endogenous antigen of unknown source, with T cells predominant in both vitreous and pars plana infiltrations. T cells subsets play an important role as a memory-effector peripheral cell. Snowbanks are formed as an effect of post inflammatory glial proliferation of fibrous astrocytes. There is also a genetic predisposition for pars planitis by human leukocyte antigen and several other genes. A coexistence of multiple sclerosis and optic neuritis has been described in numerous studies. Epiretinal membrane, cataract, cystoid macular edema, retinal detachment, retinal vasculitis, neovascularization, vitreous peripheral traction, peripheral hole formation, vitreous hemorrhage, disc edema are common complications observed in pars planitis. There is a need to expand the knowledge of the pathogenic and immunologic background of the pars planitis to create an accurate pharmacological treatment. PMID:26438050

  12. Exploration of locomotion in the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Jindal, Lavisha; Emberly, Eldon

    2015-03-01

    In many bacteria the ParA/ParB system is responsible for actively segregating DNA during replication. ParB precessively moves by hydrolyzing DNA bound ParA-ATP forming a depleted ParA region in its wake. Recent in-vitro experiments have shown that a ParB covered bead can traverse a ParA bound DNA substrate. It has been suggested that the formation of a gradient in ParA leads to diffusion-ratchet like motion of the ParB bead but its origin and potential consequences requires investigation. We have developed a deterministic model for the in-vitro ParA/ParB system and show that any amount of spatial noise in ParA can lead to the spontaneous formation of its gradient. The velocity of the bead is independent of this noise but depends on the scale over which ParA exerts a force on the bead and the scale over which ParB hydrolyzes ParA from the substrate. There is a particular ratio of these scales at which the velocity is a maximum. We also explore the effects of cooperative vs independent rebinding of ParA to the substrate. Our model shows how the driving force for ParB originates and highlights necessary conditions for directed motion in the in-vitro system that may provide insight into the in-vivo behaviour of the ParA/ParB system.

  13. [Physiology of protease-activated receptors (PARs): involvement of PARs in digestive functions].

    PubMed

    Kawabata, A; Kuroda, R; Hollenberg, M D

    1999-10-01

    The protease-activated receptor (PAR), a G protein-coupled receptor present on cell surface, mediates cellular actions of extracellular proteases. Proteases cleave the extracellular N-terminal of PAR molecules at a specific site, unmasking and exposing a novel N-terminal, a tethered ligand, that binds to the body of receptor molecules resulting in receptor activation. Amongst four distinct PARs that have been cloned, PARs 1, 3 and 4 are activated by thrombin, but PAR-2 is activated by trypsin or mast cell tryptase. Human platelets express two distinct thrombin receptors, PAR-1 and PAR-4, while murine platelets express PAR-3 and PAR-4. Apart from roles of PARs in platelet activation, PARs are distributed to a number of organs in various species, predicting their physiological importance. We have been evaluating agonists specific for each PAR, using multiple procedures including a HEK cell calcium signal receptor desensitization assay. Using specific agonists that we developed, we found the following: 1) the salivary glands express PAR-2 mRNA and secret saliva in response to PAR-2 activation; 2) pancreatic juice secretion occurs following in vivo PAR-2 activation; 3) PAR-1 and PAR-2 modulate duodenal motility. Collectively, PAR plays various physiological and/or pathophysiological roles, especially in the digestive systems, and could be a novel target for drug development. PMID:10629876

  14. Par Pond Fish, Water, and Sediment Chemistry

    SciTech Connect

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  15. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    The segregation of DNA prior to cell division is essential for faithful genetic inheritance. In many bacteria, segregation of the low-copy-number plasmids involves an active partition system composed of ParA ATPase and its stimulator protein ParB. Recent experiments suggest that ParA/ParB system motility is driven by a diffusion-ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. We develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB bound cargo. Paradoxically, the resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work sheds light on a new emergent phenomenon in which non-motor proteins work collectively via mechanochemical coupling to propel cargos -- an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.

  16. The ParB-parS Chromosome Segregation System Modulates Competence Development in Streptococcus pneumoniae

    PubMed Central

    Attaiech, Laetitia; Minnen, Anita; Kjos, Morten; Gruber, Stephan

    2015-01-01

    ABSTRACT ParB proteins bind centromere-like DNA sequences called parS sites and are involved in plasmid and chromosome segregation in bacteria. We previously showed that the opportunistic human pathogen Streptococcus pneumoniae contains four parS sequences located close to the origin of replication which are bound by ParB. Using chromatin immunoprecipitation (ChIP), we found here that ParB spreads out from one of these parS sites, parS(−1.6°), for more than 5 kb and occupies the nearby comCDE operon, which drives competence development. Competence allows S. pneumoniae to take up DNA from its environment, thereby mediating horizontal gene transfer, and is also employed as a general stress response. Mutating parS(−1.6°) or deleting parB resulted in transcriptional up-regulation of comCDE and ssbB (a gene belonging to the competence regulon), demonstrating that ParB acts as a repressor of competence. However, genome-wide transcription analysis showed that ParB is not a global transcriptional regulator. Different factors, such as the composition of the growth medium and antibiotic-induced stress, can trigger the sensitive switch driving competence. This work shows that the ParB-parS chromosome segregation machinery also influences this developmental process. PMID:26126852

  17. Parallel Climate Analysis Toolkit (ParCAT)

    Energy Science and Technology Software Center (ESTSC)

    2013-06-30

    The parallel analysis toolkit (ParCAT) provides parallel statistical processing of large climate model simulation datasets. ParCAT provides parallel point-wise average calculations, frequency distributions, sum/differences of two datasets, and difference-of-average and average-of-difference for two datasets for arbitrary subsets of simulation time. ParCAT is a command-line utility that can be easily integrated in scripts or embedded in other application. ParCAT supports CMIP5 post-processed datasets as well as non-CMIP5 post-processed datasets. ParCAT reads and writes standard netCDF files.

  18. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system.

    PubMed

    Hu, Longhua; Vecchiarelli, Anthony G; Mizuuchi, Kiyoshi; Neuman, Keir C; Liu, Jian

    2015-12-22

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos-an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183

  19. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    PubMed Central

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    2015-01-01

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA–nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos—an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183

  20. Sonosensitive theranostic liposomes for preclinical in vivo MRI-guided visualization of doxorubicin release stimulated by pulsed low intensity non-focused ultrasound.

    PubMed

    Rizzitelli, S; Giustetto, P; Cutrin, J C; Delli Castelli, D; Boffa, C; Ruzza, M; Menchise, V; Molinari, F; Aime, S; Terreno, E

    2015-03-28

    The main goal of this study was to assess the theranostic performance of a nanomedicine able to generate MRI contrast as a response to the release from liposomes of the antitumor drug Doxorubicin triggered by the local exposure to pulsed low intensity non focused ultrasounds (pLINFU). In vitro experiments showed that Gadoteridol was an excellent imaging agent for probing the release of Doxorubicin following pLINFU stimulation. On this basis, the theranostic system was investigated in vivo on a syngeneic murine model of TS/A breast cancer. MRI offered an excellent guidance for monitoring the pLINFU-stimulated release of the drug. Moreover, it provided: i) an in vivo proof of the effective release of the liposomal content, and ii) a confirmation of the therapeutic benefits of the overall protocol. Ex vivo fluorescence microscopy indicated that the good therapeutic outcome was originated from a better diffusion of the drug in the tumor following the pLINFU stimulus. Very interestingly, the broad diffusion of the drug in the tumor stroma appeared to be mediated by the presence of the liposomes themselves. The results of this study highlighted either the great potential of US-based stimuli to safely trigger the release of a drug from its nanocarrier or the associated significant therapeutic improvement. Finally, MRI demonstrated to be a valuable technique to support chemotherapy and monitoring the outcome. Furthermore, in this specific case, the theranostic agent developed has a high clinical translatability because the MRI agent utilized is already approved for human use. PMID:25626083

  1. Pulse Oximetry

    MedlinePlus

    ... www.thoracic.org amount of gases (oxygen and carbon dioxide) that are in your blood. To get an ... Also, a pulse oximeter does not measure your carbon dioxide level. How accurate is the pulse oximeter? The ...

  2. Role of PAR-4 in ovarian cancer.

    PubMed

    Meynier, Sonia; Kramer, Marianne; Ribaux, Pascale; Tille, Jean-Christophe; Delie, Florence; Petignat, Patrick; Cohen, Marie

    2015-09-01

    Prostate apoptosis response-4 (PAR-4) is considered as a tumour suppressor due to its ability to selectively induce cell apoptosis in most cancer cells. However little is known about the role of PAR-4 in ovarian cancer. In this study, we investigated for the first time the role of PAR-4 in ovarian carcinogenesis. We showed that PAR-4 mRNA level is not significantly different between healthy and cancer ovarian cells. Immunohistochemistry on ovarian tissue showed that ovarian cancer cells are positive for PAR-4 nuclear and cytoplasmic staining whereas ovarian healthy cells are negative for PAR-4 nuclear staining. We then studied the role of PAR-4 in cell apoptosis. We determined that PAR-4 induces cell apoptosis in response to stimuli, in vitro, but is also involved in the relocation of GRP78 from endoplasmic reticulum to the cell surface of ovarian cancer cell line (SKOV-3 cells). In ovo, PAR-4 decreases ovarian tumour development and increases the response to taxol treatment. These observations suggest that PAR-4 is a very interesting therapeutic target against ovarian carcinogenesis. PMID:26246468

  3. Role of PAR-4 in ovarian cancer

    PubMed Central

    Meynier, Sonia; Kramer, Marianne; Ribaux, Pascale; Tille, Jean-Christophe; Delie, Florence; Petignat, Patrick; Cohen, Marie

    2015-01-01

    Prostate apoptosis response-4 (PAR-4) is considered as a tumour suppressor due to its ability to selectively induce cell apoptosis in most cancer cells. However little is known about the role of PAR-4 in ovarian cancer. In this study, we investigated for the first time the role of PAR-4 in ovarian carcinogenesis. We showed that PAR-4 mRNA level is not significantly different between healthy and cancer ovarian cells. Immunohistochemistry on ovarian tissue showed that ovarian cancer cells are positive for PAR-4 nuclear and cytoplasmic staining whereas ovarian healthy cells are negative for PAR-4 nuclear staining. We then studied the role of PAR-4 in cell apoptosis. We determined that PAR-4 induces cell apoptosis in response to stimuli, in vitro, but is also involved in the relocation of GRP78 from endoplasmic reticulum to the cell surface of ovarian cancer cell line (SKOV-3 cells). In ovo, PAR-4 decreases ovarian tumour development and increases the response to taxol treatment. These observations suggest that PAR-4 is a very interesting therapeutic target against ovarian carcinogenesis. PMID:26246468

  4. Guided acoustic wave inspection system

    DOEpatents

    Chinn, Diane J.

    2004-10-05

    A system for inspecting a conduit for undesirable characteristics. A transducer system induces guided acoustic waves onto said conduit. The transducer system detects the undesirable characteristics of the conduit by receiving guided acoustic waves that contain information about the undesirable characteristics. The conduit has at least two sides and the transducer system utilizes flexural modes of propagation to provide inspection using access from only the one side of the conduit. Cracking is detected with pulse-echo testing using one transducer to both send and receive the guided acoustic waves. Thinning is detected in through-transmission testing where one transducer sends and another transducer receives the guided acoustic waves.

  5. Laser guiding at>1018 W/cm2 in plasma channels formed by theignitor heater method

    SciTech Connect

    Geddes, C.G.R.; Toth, C.; vanTilborg, J.; Leemans, W.P.

    2004-05-01

    Experiments explore guiding of intense laser pulses, optimization using channel formation beams and gas jet targets, and the interplay of channel guiding and relativistic self guiding. Impact on laser wakefield particle acceleration is being assessed.

  6. Pars triangularis asymmetry and language dominance.

    PubMed Central

    Foundas, A L; Leonard, C M; Gilmore, R L; Fennell, E B; Heilman, K M

    1996-01-01

    The pars triangular is a portion of Broca's area. The convolutions that form the inferior and caudal extent of the pars triangularis include the anterior horizontal and anterior ascending rami of the sylvian fissure, respectively. To learn if there are anatomic asymmetries of the pars triangularis, these convolutions were measured on volumetric magnetic resonance imaging scans of 11 patients who had undergone selective hemispheric anesthesia (Wada testing) to determine hemispheric speech and language lateralization. Of the 10 patients with language lateralized to the left hemisphere, 9 had a leftward asymmetry of the pars triangularis. The 1 patient with language lateralized to the right hemisphere had a significant rightward asymmetry of the pars triangularis. Our data suggest that asymmetries of the pars triangularis may be related to speech-language lateralization. Images Fig. 1 PMID:8570622

  7. "It was like reading a detective novel": Using PAR to work together for culture change.

    PubMed

    Fortune, Darla; McKeown, Janet; Dupuis, Sherry; de Witt, Lorna

    2015-08-01

    Participatory action research (PAR), with its focus on engagement and collaboration, is uniquely suited to enhancing culture change initiatives in dementia care. Yet, there is limited literature of its application to culture change approaches in care settings, and even less in dementia specific care contexts. To address these gaps in the literature, the purpose of this paper is to examine the complexities of a PAR project aimed at changing the culture of dementia care in two diverse dementia care settings, including a long term care (LTC) and community care setting. Drawing from data gathered throughout the PAR process, we unpack the challenges experienced by participants working together to guide culture change within their respective care settings. These challenges include: overextending selves through culture change participation; fluctuating group membership; feeling uncertainty, confusion and apprehension about the process; frustratingly slow process; and seeking diverse group representation in decision making. We also highlight the potential for appreciative inquiry (AI) to be integrated with PAR to guide a process whereby participants involved in culture change initiatives can develop strategies to mitigate challenges they experience. We view the challenges and strategies shared here as being constructive to would-be culture change agents and hope this paper will move others to consider the use of PAR when engaging in culture change initiatives. PMID:26162724

  8. PULSE GENERATOR

    DOEpatents

    Roeschke, C.W.

    1957-09-24

    An improvement in pulse generators is described by which there are produced pulses of a duration from about 1 to 10 microseconds with a truly flat top and extremely rapid rise and fall. The pulses are produced by triggering from a separate input or by modifying the current to operate as a free-running pulse generator. In its broad aspect, the disclosed pulse generator comprises a first tube with an anode capacitor and grid circuit which controls the firing; a second tube series connected in the cathode circuit of the first tube such that discharge of the first tube places a voltage across it as the leading edge of the desired pulse; and an integrator circuit from the plate across the grid of the second tube to control the discharge time of the second tube, determining the pulse length.

  9. PAR for the Course: A Congruent Pedagogical Approach for a PAR Methods Class

    ERIC Educational Resources Information Center

    Hammond, Joyce D.; Hicks, Maria; Kalman, Rowenn; Miller, Jason

    2005-01-01

    In the past two years, three graduate students and a senior faculty member have co-taught a participatory action research (PAR) course to undergraduate and graduate students. In this article the co-teachers advocate a set of pedagogical principles and practices in a PAR-oriented classroom that establishes congruency with community PAR projects in…

  10. Pulse stretcher

    DOEpatents

    Horton, J.A.

    1994-05-03

    Apparatus for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse is disclosed. The apparatus uses a White cell having a plurality of optical delay paths of successively increasing number of passes between the field mirror and the objective mirrors. A pulse from a laser travels through a multi-leg reflective path between a beam splitter and a totally reflective mirror to the laser output. The laser pulse is also simultaneously injected through the beam splitter to the input mirrors of the optical delay paths. The pulses from the output mirrors of the optical delay paths go simultaneously to the laser output and to the input mirrors of the longer optical delay paths. The beam splitter is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output. 6 figures.

  11. Pulsed power

    NASA Astrophysics Data System (ADS)

    Stone, David H.

    Pulsed power systems are critical elements for such prospective weapons technologies as high-power microwaves, electrothermal and electromagnetic projectile launchers, neutral particle beams, space-based FELs, ground-based lasers, and charged particle beams. Pulsed power will also be essential for the development of nonweapon military systems such as lidars and ultrawideband radars, and could serve as the bases for nuclear weapon effect simulators. The pulsed power generation requirements for each of these systems is considered.

  12. Pulse Voltammetry

    NASA Astrophysics Data System (ADS)

    Stojek, Zbigniew

    The idea of imposing potential pulses and measuring the currents at the end of each pulse was proposed by Barker in a little-known journal as early as in 1958 [1]. However, the first reliable trouble-free and affordable polarographs offering voltammetric pulse techniques appeared on the market only in the 1970s. This delay was due to some limitations on the electronic side. In the 1990s, again substantial progress in electrochemical pulse instrumentation took place. This was related to the introduction of microprocessors, computers, and advanced software.

  13. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  14. ParAB Partition Dynamics in Firmicutes: Nucleoid Bound ParA Captures and Tethers ParB-Plasmid Complexes

    PubMed Central

    Lioy, Virginia S.; Volante, Andrea; Soberón, Nora E.; Lurz, Rudi; Ayora, Silvia; Alonso, Juan C.

    2015-01-01

    In Firmicutes, small homodimeric ParA-like (δ2) and ParB-like (ω2) proteins, in concert with cis-acting plasmid-borne parS and the host chromosome, secure stable plasmid inheritance in a growing bacterial population. This study shows that (ω:YFP)2 binding to parS facilitates plasmid clustering in the cytosol. (δ:GFP)2 requires ATP binding but not hydrolysis to localize onto the cell’s nucleoid as a fluorescent cloud. The interaction of (δ:CFP)2 or δ2 bound to the nucleoid with (ω:YFP)2 foci facilitates plasmid capture, from a very broad distribution, towards the nucleoid and plasmid pairing. parS-bound ω2 promotes redistribution of (δ:GFP)2, leading to the dynamic release of (δ:GFP)2 from the nucleoid, in a process favored by ATP hydrolysis and protein-protein interaction. (δD60A:GFP)2, which binds but cannot hydrolyze ATP, also forms unstable complexes on the nucleoid. In the presence of ω2, (δD60A:GFP)2 accumulates foci or patched structures on the nucleoid. We propose that (δ:GFP)2 binding to different nucleoid regions and to ω2-parS might generate (δ:GFP)2 gradients that could direct plasmid movement. The iterative pairing and unpairing cycles may tether plasmids equidistantly on the nucleoid to ensure faithful plasmid segregation by a mechanism compatible with the diffusion-ratchet mechanism as proposed from in vitro reconstituted systems. PMID:26161642

  15. PULSE AMPLIFIER

    DOEpatents

    Johnstone, C.W.

    1958-06-17

    The improvement of pulse amplifiers used with scintillation detectors is described. The pulse amplifier circuit has the advantage of reducing the harmful effects of overloading cause by large signal inputs. In general the pulse amplifier circuit comprises two amplifier tubes with the input pulses applied to one amplifier grid and coupled to the second amplifier tube through a common cathode load. The output of the second amplifier is coupled from the plate circuit to a cathode follower tube grid and a diode tube in connected from grid to cathode of the cathode follower tube. Degenerative feedback is provided in the second amplifier by coupling a signal from the cathode follower cathode to the second amplifier grid. The circuit proqides moderate gain stability, and overload protection for subsequent pulse circuits.

  16. Wavefront Measurement for Laser-Guiding Diagnostic

    SciTech Connect

    University of Chicago; Lawrence Berkeley National Laboratory; Shiraishi, S.; Gonsalves, A. J.; Lin, C.; Nakamura, K.; Osterhoff, J.; Sokollik, T.; Tilborg, J. van; Geddes, C. G. R.; Schroeder, C. B.; Toth, Cs.; Esarey, E.; Leemans, W. P.

    2010-06-01

    The wavefront of a short laser pulse after interaction in a laser-plasma accelerator (LPA) was measured to diagnose laser-guiding quality. Experiments were performed on a 100 TW class laser at the LOASIS facility of LBNL using a hydrogenfilled capillary discharge waveguide. Laser-guiding with a pre-formed plasma channel allows the laser pulse to propagate over many Rayleigh lengths at high intensity and is crucial to accelerate electrons to the highest possible energy. Efficient coupling of laser energy into the plasma is realized when the laser and the channel satisfy a matched guiding condition, in which the wavefront remains flat within the channel. Using a wavefront sensor, the laser-guiding quality was diagnosed based on the wavefront of the laser pulse exiting the plasma channel. This wavefront diagnostic will contribute to achieving controlled, matched guiding in future experiments.

  17. Wavefront Measurement for Laser-Guiding Diagnostic

    SciTech Connect

    Shiraishi, S.; Gonsalves, A. J.; Lin, C.; Nakamura, K.; Osterhoff, J.; Sokollik, T.; van Tilborg, J.; Geddes, C. G. R.; Schroeder, C. B.; Toth, Cs.; Esarey, E.; Leemans, W. P.

    2010-11-04

    The wavefront of a short laser pulse after interaction in a laser-plasma accelerator (LPA) was measured to diagnose laser-guiding quality. Experiments were performed on a 100 TW class laser at the LOASIS facility of LBNL using a hydrogen-filled capillary discharge waveguide. Laser-guiding with a pre-formed plasma channel allows the laser pulse to propagate over many Rayleigh lengths at high intensity and is crucial to accelerate electrons to the highest possible energy. Efficient coupling of laser energy into the plasma is realized when the laser and the channel satisfy a matched guiding condition, in which the wavefront remains flat within the channel. Using a wavefront sensor, the laser-guiding quality was diagnosed based on the wavefront of the laser pulse exiting the plasma channel. This wavefront diagnostic will contribute to achieving controlled, matched guiding in future experiments.

  18. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  19. Flexible operability and amplification of gray pulses.

    PubMed

    Li, Xingliang; Zhang, Shumin; Han, Mengmeng; Zhang, Huaxing; Wen, Fang; Yang, Zhenjun

    2014-07-15

    We have investigated experimentally the flexible production and amplification of gray pulses for the first time to our knowledge. Switchable wavelengths, tunable pulse-widths, and adjustable contrasts have all been obtained in a fiber laser. Amplification of gray pulses was also experimentally investigated in detail. The contrast of the pulses could also be increased in an amplifier. The robust stability that results from the interactions between adjacent harmonic mode locking counterparts of gray pulses was found to last for up to ten hours. To the best of our knowledge, the gray pulses trains we have generated are the most stable achieved to date in an all-fiber laser system. This finding can be used as a guide for the establishment of robust gray pulses as laser sources. PMID:25121665

  20. Pulse Voltammetry.

    ERIC Educational Resources Information Center

    Osteryoung, Janet

    1983-01-01

    Discusses the nature of pulse voltammetry, indicating that its widespread use arises from good sensitivity and detection limits and from ease of application and low cost. Provides analytical and mechanistic applications of the procedure. (JN)

  1. Comparative cactus architecture and par interception

    SciTech Connect

    Geller, G.N.; Nobel, P.S. )

    1987-07-01

    Because CO{sup 2} uptake by cacti can be limited by low levels of photosynthetically active radiation (PAR) and because plant form affects PAR interception, various cactus forms were studied using a computer model, field measurements, and laboratory phototropic studies. Model predictions indicated that CO{sub 2} uptake by individual stems at an equinox was greatest when the stem were vertical, but at the summer and the winter solstice CO{sub 2} uptake was greatest for stems titled 30{degree} away from the equator. Stem tilting depended on form and taxonomic group. Not only can the shape of cacti be affected by PAR, but also shape influences PAR interception and hence CO{sub 2} uptake.

  2. Pulse stretcher

    DOEpatents

    Horton, James A.

    1994-01-01

    Apparatus (20) for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse. The apparatus (20) uses a White cell (10) having a plurality of optical delay paths (18a-18d) of successively increasing number of passes between the field mirror (13) and the objective mirrors (11 and 12). A pulse (26) from a laser (27) travels through a multi-leg reflective path (28) between a beam splitter (21) and a totally reflective mirror (24) to the laser output (37). The laser pulse (26) is also simultaneously injected through the beam splitter (21) to the input mirrors (14a-14d) of the optical delay paths (18a-18d). The pulses from the output mirrors (16a-16d) of the optical delay paths (18a-18d) go simultaneously to the laser output (37) and to the input mirrors ( 14b-14d) of the longer optical delay paths. The beam splitter (21) is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output (37).

  3. Radioecological implications of the Par Pond drawdown

    SciTech Connect

    Hickey, H.; Whicker, F.W.

    1991-12-05

    The drawdown of the Par Pond reservoir created dramatic alterations in this formerly stable lentic ecosystem. In addition, the radiation environment at Par Pond has changed significantly because of the exposure of Cesium 137-contaminated sediments and the appearance of new transport pathways to the terrestrial environment. In response to this situation, SREL was asked to study the radioecological implications of the reservoir drawdown. This report contains the objectives, methods, and results of the SREL study.

  4. Structural analysis of the ParR/parC plasmid partition complex.

    PubMed

    Møller-Jensen, Jakob; Ringgaard, Simon; Mercogliano, Christopher P; Gerdes, Kenn; Löwe, Jan

    2007-10-17

    Accurate DNA partition at cell division is vital to all living organisms. In bacteria, this process can involve partition loci, which are found on both chromosomes and plasmids. The initial step in Escherichia coli plasmid R1 partition involves the formation of a partition complex between the DNA-binding protein ParR and its cognate centromere site parC on the DNA. The partition complex is recognized by a second partition protein, the actin-like ATPase ParM, which forms filaments required for the active bidirectional movement of DNA replicates. Here, we present the 2.8 A crystal structure of ParR from E. coli plasmid pB171. ParR forms a tight dimer resembling a large family of dimeric ribbon-helix-helix (RHH)2 site-specific DNA-binding proteins. Crystallographic and electron microscopic data further indicate that ParR dimers assemble into a helix structure with DNA-binding sites facing outward. Genetic and biochemical experiments support a structural arrangement in which the centromere-like parC DNA is wrapped around a ParR protein scaffold. This structure holds implications for how ParM polymerization drives active DNA transport during plasmid partition. PMID:17898804

  5. Techniques for measuring intercepted and absorbed PAR in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.

    1984-01-01

    The quantity of radiation potentially available for photosynthesis that is captured by the crop is best described as absorbed photosynthetically active radiation (PAR). Absorbed PAR (APAR) is the difference between descending and ascending fluxes. The four components of APAR were measured above and within two planting densities of corn (Zea mays L.) and several methods of measuring and estimating APAR were examined. A line quantum sensor that spatially averages the photosynthetic photon flux density provided a rapid and portable method of measuring APAR. PAR reflectance from the soil (Typic Argiaquoll) surface decreased from 10% to less than 1% of the incoming PAR as the canopy cover increased. PAR reflectance from the canopy decreased to less than 3% at maximum vegetative cover. Intercepted PAR (1 - transmitted PAR) generally overestimated absorbed PAR by less than 4% throughout most of the growing season. Thus intercepted PAR appears to be a reasonable estimate of absorbed PAR.

  6. ParCAT: Parallel Climate Analysis Toolkit

    SciTech Connect

    Smith, Brian E.; Steed, Chad A.; Shipman, Galen M.; Ricciuto, Daniel M.; Thornton, Peter E.; Wehner, Michael; Williams, Dean N.

    2013-01-01

    Climate science is employing increasingly complex models and simulations to analyze the past and predict the future of Earth s climate. This growth in complexity is creating a widening gap between the data being produced and the ability to analyze the datasets. Parallel computing tools are necessary to analyze, compare, and interpret the simulation data. The Parallel Climate Analysis Toolkit (ParCAT) provides basic tools to efficiently use parallel computing techniques to make analysis of these datasets manageable. The toolkit provides the ability to compute spatio-temporal means, differences between runs or differences between averages of runs, and histograms of the values in a data set. ParCAT is implemented as a command-line utility written in C. This allows for easy integration in other tools and allows for use in scripts. This also makes it possible to run ParCAT on many platforms from laptops to supercomputers. ParCAT outputs NetCDF files so it is compatible with existing utilities such as Panoply and UV-CDAT. This paper describes ParCAT and presents results from some example runs on the Titan system at ORNL.

  7. PULSE COUNTER

    DOEpatents

    Trumbo, D.E.

    1959-02-10

    A transistorized pulse-counting circuit adapted for use with nuclear radiation detecting detecting devices to provide a small, light weight portable counter is reported. The small size and low power requirements of the transistor are of particular value in this instance. The circuit provides an adjustable count scale with a single transistor which is triggered by the accumulated charge on a storage capacitor.

  8. Colostomy Guide

    MedlinePlus

    ... window. My Saved Articles » My ACS » Colostomy: A Guide Download Printable Version [PDF] » ( En español ) Colostomy surgery ... the activities you enjoyed in the past. This guide will help you better understand colostomy – what it ...

  9. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation.

    PubMed

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara

    2016-04-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  10. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    PubMed Central

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  11. Pulsed hydrojet

    DOEpatents

    Bohachevsky, I.O.; Torrey, M.D.

    1986-06-10

    An underwater pulsed hydrojet propulsion system is provided for accelerating and propelling a projectile or other vessel. A reactant, such as lithium, is fluidized and injected into a water volume. The resulting reaction produces an energy density in a time effective to form a steam pocket. Thrust flaps or baffles direct the pressure from the steam pocket toward an exit nozzle for accelerating a water volume to create thrust. A control system regulates the dispersion of reactant to control thrust characteristics.

  12. Par-4: A New Activator of Myosin Phosphatase

    PubMed Central

    Vetterkind, Susanne; Lee, Eunhee; Sundberg, Eric; Poythress, Ransom H.; Tao, Terence C.; Preuss, Ute

    2010-01-01

    Myosin phosphatase (MP) is a key regulator of myosin light chain (LC20) phosphorylation, a process essential for motility, apoptosis, and smooth muscle contractility. Although MP inhibition is well studied, little is known about MP activation. We have recently demonstrated that prostate apoptosis response (Par)-4 modulates vascular smooth muscle contractility. Here, we test the hypothesis that Par-4 regulates MP activity directly. We show, by proximity ligation assays, surface plasmon resonance and coimmunoprecipitation, that Par-4 interacts with the targeting subunit of MP, MYPT1. Binding is mediated by the leucine zippers of MYPT1 and Par-4 and reduced by Par-4 phosphorylation. Overexpression of Par-4 leads to increased phosphatase activity of immunoprecipitated MP, whereas small interfering RNA knockdown of endogenous Par-4 significantly decreases MP activity and increases MYPT1 phosphorylation. LC20 phosphorylation assays demonstrate that overexpression of Par-4 reduces LC20 phosphorylation. In contrast, a phosphorylation site mutant, but not wild-type Par-4, interferes with zipper-interacting protein kinase (ZIPK)-mediated MP inhibition. We conclude from our results Par-4 operates through a “padlock” model in which binding of Par-4 to MYPT1 activates MP by blocking access to the inhibitory phosphorylation sites, and inhibitory phosphorylation of MYPT1 by ZIPK requires “unlocking” of Par-4 by phosphorylation and displacement of Par-4 from the MP complex. PMID:20130087

  13. suPAR and Team Nephrology

    PubMed Central

    2014-01-01

    Primary focal segmental glomerulosclerosis (FSGS) accounts for nearly 10 % of patients who require renal replacement therapy. Elevated circulating levels of soluble urokinase receptor (suPAR) have been identified as a biomarker to discriminate primary FSGS from other glomerulopathies. Subsequent reports have questioned the diagnostic utility of this test. In a study in BMC Medicine, Huang et al. demonstrate that urinary soluble urokinase receptor (suPAR) excretion assists in distinguishing primary FSGS from other glomerular diseases, and that high plasma suPAR concentrations are not directly linked to a decline in glomerular filtration rate (GFR). This observation suggests that further investigation of suPAR is warranted in patients with FSGS. It should be interpreted in light of a recent report that B7-1 is expressed in the podocytes of a subset of patients with FSGS, and that blocking this molecule may represent the first successful targeted intervention for this disease. These advances highlight the rapid pace of scientific progress in the field of nephrology. Nephrologists should work together, share resources, and expedite the design of protocols to evaluate these novel biomarkers in a comprehensive and scientifically valid manner. Please see related article http://www.biomedcentral.com/1741-7015/12/81. PMID:24885021

  14. suPAR and Team Nephrology.

    PubMed

    Trachtman, Howard

    2014-01-01

    Primary focal segmental glomerulosclerosis (FSGS) accounts for nearly 10 % of patients who require renal replacement therapy. Elevated circulating levels of soluble urokinase receptor (suPAR) have been identified as a biomarker to discriminate primary FSGS from other glomerulopathies. Subsequent reports have questioned the diagnostic utility of this test. In a study in BMC Medicine, Huang et al. demonstrate that urinary soluble urokinase receptor (suPAR) excretion assists in distinguishing primary FSGS from other glomerular diseases, and that high plasma suPAR concentrations are not directly linked to a decline in glomerular filtration rate (GFR). This observation suggests that further investigation of suPAR is warranted in patients with FSGS. It should be interpreted in light of a recent report that B7-1 is expressed in the podocytes of a subset of patients with FSGS, and that blocking this molecule may represent the first successful targeted intervention for this disease. These advances highlight the rapid pace of scientific progress in the field of nephrology. Nephrologists should work together, share resources, and expedite the design of protocols to evaluate these novel biomarkers in a comprehensive and scientifically valid manner. PMID:24885021

  15. View from east to west of PAR site storage building; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from east to west of PAR site storage building; formerly PAR dispensary - Stanley R. Mickelsen Safeguard Complex, Storage Building, Across street from Family Housing Units 110 & 111, Nekoma, Cavalier County, ND

  16. View from west to east of PAR site resident engineer's ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from west to east of PAR site resident engineer's office building (REOB) - Stanley R. Mickelsen Safeguard Complex, Resident Engineers Office Building, Southeast of intersection of PAR Access Road & Fourth Avenue, Nekoma, Cavalier County, ND

  17. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition Assembly

    SciTech Connect

    B Chaudhuri; S Gupta; V Urban; M Chance; R DMello; L Smith; K Lyons; J Gee

    2011-12-31

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  18. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition

    SciTech Connect

    Chaudhuri, Barnali; Gupta, Sayan; Urban, Volker S; Chance, Mark; D'Mello, Rhijuta; Smith, Lauren; Lyons, Kelly; Gee, Jessica

    2010-01-01

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  19. PULSE COLUMN

    DOEpatents

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  20. Tapered pulse tube for pulse tube refrigerators

    DOEpatents

    Swift, Gregory W.; Olson, Jeffrey R.

    1999-01-01

    Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

  1. Monoenergetic Electronic Beam Production Using Dual Collinear Laser Pulses

    SciTech Connect

    Thomas, A. G. R.; Mangles, S. P. D.; Dangor, A. E.; Kamperidis, C.; Krushelnick, K.; Najmudin, Z.; Murphy, C. D.; Foster, P.; Lancaster, K. L.; Norreys, P. A.; Gallacher, J. G.; Jaroszynski, D. A.; Viskup, R.

    2008-06-27

    The production of monoenergetic electron beams by two copropagating ultrashort laser pulses is investigated both by experiment and using particle-in-cell simulations. By proper timing between guiding and driver pulses, a high-amplitude plasma wave is generated and sustained for longer than is possible with either of the laser pulses individually, due to plasma waveguiding of the driver by the guiding pulse. The growth of the plasma wave is inferred by the measurement of monoenergetic electron beams with low divergence that are not measured by using either of the pulses individually. This scheme can be easily implemented and may allow more control of the interaction than is available to the single pulse scheme.

  2. Lens implant surgery in pars planitis.

    PubMed

    Michelson, J B; Friedlaender, M H; Nozik, R A

    1990-08-01

    Intraocular lens (IOL) implantation is usually contraindicated in eyes with active inflammation, but patients with "burned-out" pars planitis also may be considered as candidates. Fifteen of 16 eyes in eight patients underwent extracapsular cataract extraction (ECCE) with posterior chamber IOL (PC IOL) implantation combined with pars plana vitrectomy for both cataracts and chronic cystoid macular edema (CME); 60% achieved visual acuity of 20/40 or better. Even with "low-grade" inflammation in these patients, however, a persistent veil of debris accumulated over the posterior and anterior surface of the IOL. One patient (patient 2) required 27 YAG procedures for two eyes, and another required 11 YAG procedures and eventual removal of the IOL. Another patient required surgical "brushing-off" of the IOL and vitrectomy. Even in eyes with "burned-out" uveitis, a continual low-grade inflammation may complicate the use of IOL implantation. PMID:2402411

  3. Par Pond refill water quality sampling

    SciTech Connect

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column.

  4. Combined DSEK and Transconjunctival Pars Plana Vitrectomy

    PubMed Central

    Sane, Mona; Shaikh, Naazli

    2016-01-01

    We report here three patients who underwent combined Descemet's stripping with endothelial keratoplasty and transconjunctival pars plana vitrectomy for bullous keratopathy and posterior segment pathology. A surgical technique and case histories are described. Anatomic and visual outcomes of combined Descemet's stripping with endothelial keratoplasty and vitrectomy were excellent. Our experience provides technical guidelines and limitations. The combined minimally invasive techniques allow for rapid anatomical recovery and return of function and visual acuity in a single sitting. PMID:27413563

  5. Mechanisms of apoptosis by the tumor suppressor Par-4.

    PubMed

    Hebbar, Nikhil; Wang, Chi; Rangnekar, Vivek M

    2012-12-01

    Par-4 is a pro-apoptotic, tumor suppressor protein that induces apoptosis selectively in cancer cells. Endoplasmic reticulum-stress and higher levels of protein kinase A in tumor cells confer the coveted feature of cancer selective response to extracellular and intracellular Par-4, respectively. Recent studies have shown that systemic Par-4 confers resistance to tumor growth in mice, and that tumor-resistance is transferable by bone-marrow transplantation. Moreover, recombinant Par-4 inhibits the growth of tumors in mice. As systemic Par-4 induces apoptosis via cell surface GRP78, strategies that promote GRP78 trafficking to the cell surface are expected sensitize cancer cells to circulating levels of Par-4. This review illustrates the domains and mechanisms by which Par-4 orchestrates the apoptotic process in both cell culture models and in physiological settings. PMID:22552839

  6. A Single parS Sequence from the Cluster of Four Sites Closest to oriC Is Necessary and Sufficient for Proper Chromosome Segregation in Pseudomonas aeruginosa

    PubMed Central

    Jecz, Paulina; Bartosik, Aneta A.; Glabski, Krzysztof; Jagura-Burdzy, Grazyna

    2015-01-01

    Among the mechanisms that control chromosome segregation in bacteria are highly-conserved partitioning systems comprising three components: ParA protein (a deviant Walker-type ATPase), ParB protein (a DNA-binding element) and multiple cis-acting palindromic centromere-like sequences, designated parS. Ten putative parS sites have been identified in the P. aeruginosa PAO1 genome, four localized in close proximity of oriC and six, diverged by more than one nucleotide from a perfect palindromic sequence, dispersed along the chromosome. Here, we constructed and analyzed P. aeruginosa mutants deprived of each single parS sequence and their different combinations. The analysis included evaluation of a set of phenotypic features, chromosome segregation, and ParB localization in the cells. It was found that ParB binds specifically to all ten parS sites, although with different affinities. The P. aeruginosa parS mutant with all ten parS sites modified (parSnull) is viable however it demonstrates the phenotype characteristic for parAnull or parBnull mutants: slightly slower growth rate, high frequency of anucleate cells, and defects in motility. The genomic position and sequence of parS determine its role in P. aeruginosa biology. It transpired that any one of the four parS sites proximal to oriC (parS1 to parS4), which are bound by ParB with the highest affinity, is necessary and sufficient for the parABS role in chromosome partitioning. When all these four sites are mutated simultaneously, the strain shows the parSnull phenotype, which indicates that none of the remaining six parS sites can substitute for these four oriC-proximal sites in this function. A single ectopic parS2 (inserted opposite oriC in the parSnull mutant) facilitates ParB organization into regularly spaced condensed foci and reverses some of the mutant phenotypes but is not sufficient for accurate chromosome segregation. PMID:25794281

  7. Electromagnetically Induced Guiding of Counter-propagating Lasers in Plasmas

    SciTech Connect

    First Author = G. Shvets; A. Pukhov

    1998-05-01

    The interaction of counter-propagating laser pulses in a plasma is considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order the plasma period) laser pulse can also be nonlinearly focused by a long counter-propagating beam which extends over the entire guiding length. This phenomenon of electromagnetically induced guiding can be utilized in laser-driven plasma accelerators.

  8. Pulse propagation and electron acceleration in a corrugated plasma channel.

    PubMed

    Palastro, J P; Antonsen, T M; Morshed, S; York, A G; Milchberg, H M

    2008-03-01

    A preformed plasma channel provides a guiding structure for laser pulses unbound by the intensity thresholds of standard waveguides. The recently realized corrugated plasma channel [Layer, Phys. Rev. Lett. 99, 035001 (2007)] allows for the guiding of laser pulses with subluminal spatial harmonics. These spatial harmonics can be phase matched to high energy electrons, making the corrugated plasma channel ideal for the acceleration of electrons. We present a simple analytic model of pulse propagation in a corrugated plasma channel and examine the laser-electron beam interaction. Simulations show accelerating gradients of several hundred MeV/cm for laser powers much lower than required by standard laser wakefield schemes. PMID:18517531

  9. Medication Guide

    MedlinePlus

    ... who have a history of asthma or other respiratory disorders. Additionally, beta blockers can change cardiac activity by decreasing the amount of blood the heart pumps out, which may reduce the pulse rate and/or slow down the heart's response rate ...

  10. Teachers Guide.

    ERIC Educational Resources Information Center

    Linsky, Ronald B.; Schnitger, Ronald L.

    This guide provides teachers with copies of the materials given to students participating in the oceanography program of the Orange County Floating Laboratory Program and provides information concerning colleges and universities offering courses in oceanography and marine science, source of films, and sources of publications concerning the Navy's…

  11. Coatings Guide

    EPA Science Inventory

    The Coatings Guide is a free online information resource that focuses on alternative, low-emission coatings for metal, plastic, and architectural substrates. Developed cooperatively by the U.S. EPA's Office of Research and Development and Research Triangle Institute (RTI) Interna...

  12. Medication Guide

    MedlinePlus

    ... Quit Smoking Benefits of Quitting Health Effects of Smoking Secondhand Smoke Withdrawal Ways to Quit QuitGuide Pregnancy & Motherhood Pregnancy & Motherhood Before Your Baby is Born From Birth to 2 Years Quitting for Two SmokefreeMom Healthy Kids Parenting & ... Weight Management Weight Management ...

  13. Homebuyer's Guide.

    ERIC Educational Resources Information Center

    Sindt, Roger P.; Harris, Jack

    Designed to assist prospective buyers in making such important decisions as whether to buy a new or older home and within what price range, the guide provides information on the purchase process. Discussion of the purchase process covers the life-cycle costs (recurring homeownership costs that must be met every month); selection of a home;…

  14. ADJUSTABLE DOUBLE PULSE GENERATOR

    DOEpatents

    Gratian, J.W.; Gratian, A.C.

    1961-08-01

    >A modulator pulse source having adjustable pulse width and adjustable pulse spacing is described. The generator consists of a cross coupled multivibrator having adjustable time constant circuitry in each leg, an adjustable differentiating circuit in the output of each leg, a mixing and rectifying circuit for combining the differentiated pulses and generating in its output a resultant sequence of negative pulses, and a final amplifying circuit for inverting and square-topping the pulses. (AEC)

  15. Escherichia coli low-copy-number plasmid R1 centromere parC forms a U-shaped complex with its binding protein ParR

    PubMed Central

    Hoischen, C.; Bussiek, M.; Langowski, J.; Diekmann, S.

    2008-01-01

    The Escherichia coli low-copy-number plasmid R1 contains a segregation machinery composed of parC, ParR and parM. The R1 centromere-like site parC contains two separate sets of repeats. By atomic force microscopy (AFM) we show here that ParR molecules bind to each of the 5-fold repeated iterons separately with the intervening sequence unbound by ParR. The two ParR protein complexes on parC do not complex with each other. ParR binds with a stoichiometry of about one ParR dimer per each single iteron. The measured DNA fragment lengths agreed with B-form DNA and each of the two parC 5-fold interon DNA stretches adopts a linear path in its complex with ParR. However, the overall parC/ParR complex with both iteron repeats bound by ParR forms an overall U-shaped structure: the DNA folds back on itself nearly completely, including an angle of ∼150°. Analysing linear DNA fragments, we never observed dimerized ParR complexes on one parC DNA molecule (intramolecular) nor a dimerization between ParR complexes bound to two different parC DNA molecules (intermolecular). This bacterial segrosome is compared to other bacterial segregation complexes. We speculate that partition complexes might have a similar overall structural organization and, at least in part, common functional properties. PMID:18056157

  16. Revisit on dynamic radiation forces induced by pulsed Gaussian beams.

    PubMed

    Wang, Li-Gang; Chai, Hai-Shui

    2011-07-18

    Motivated by the recent optical trapping experiments using ultra-short pulsed lasers [Opt. Express 18, 7554 (2010); Appl. Opt. 48, G33 (2009)], in this paper we have re-investigated the trapping effects of the pulsed radiation force (PRF), which is induced by a pulsed Gaussian beam acting on a Rayleigh dielectric sphere. Based on our previous model [Opt. Express 15, 10615 (2007)], we have considered the effects arisen from both the transverse and axial PRFs, which lead to the different behaviors of both velocities and displacements of a Rayleigh particle within a pulse duration. Our analysis shows that, for the small-sized Rayleigh particles, when the pulse has the large pulse duration, it might provide the three-dimensional optical trapping; and when the pulse has the short pulse duration, it only provides the two-dimensional optical trapping with the axial movement along the pulse propagation. When the particle is in the vacuum or in the situation with the very weak Brownian motion, the particle can always be trapped stably due to the particle's cumulative momentum transferred from the pulse, and only in this case the trapping effect is independent of pulse duration. Finally, we have predicted that for the large-sized Rayleigh particles, the pulse beam can only provide the two-dimensional optical trap (optical guiding). Our results provide the important information about the trapping mechanism of pulsed tweezers. PMID:21934801

  17. uPAR-targeted multimodal tracer for pre- and intraoperative imaging in cancer surgery

    PubMed Central

    van Willigen, Danny M.; Stammes, Marieke A.; Prevoo, Hendrica A.J.M.; Tummers, Quirijn R.J.G.; Mazar, Andrew P.; Beekman, Freek J.; Kuppen, Peter J.K.; van de Velde, Cornelis J.H.; Löwik, Clemens W.G.M.; Frangioni, John V.; van Leeuwen, Fijs W.B.; Sier, Cornelis F.M.; Vahrmeijer, Alexander L.

    2015-01-01

    Pre- and intraoperative diagnostic techniques facilitating tumor staging are of paramount importance in colorectal cancer surgery. The urokinase receptor (uPAR) plays an important role in the development of cancer, tumor invasion, angiogenesis, and metastasis and over-expression is found in the majority of carcinomas. This study aims to develop the first clinically relevant anti-uPAR antibody-based imaging agent that combines nuclear (111In) and real-time near-infrared (NIR) fluorescent imaging (ZW800-1). Conjugation and binding capacities were investigated and validated in vitro using spectrophotometry and cell-based assays. In vivo, three human colorectal xenograft models were used including an orthotopic peritoneal carcinomatosis model to image small tumors. Nuclear and NIR fluorescent signals showed clear tumor delineation between 24h and 72h post-injection, with highest tumor-to-background ratios of 5.0 ± 1.3 at 72h using fluorescence and 4.2 ± 0.1 at 24h with radioactivity. 1-2 mm sized tumors could be clearly recognized by their fluorescent rim. This study showed the feasibility of an uPAR-recognizing multimodal agent to visualize tumors during image-guided resections using NIR fluorescence, whereas its nuclear component assisted in the pre-operative non-invasive recognition of tumors using SPECT imaging. This strategy can assist in surgical planning and subsequent precision surgery to reduce the number of incomplete resections. PMID:25895028

  18. uPAR-targeted multimodal tracer for pre- and intraoperative imaging in cancer surgery.

    PubMed

    Boonstra, Martin C; van Driel, Pieter B A A; van Willigen, Danny M; Stammes, Marieke A; Prevoo, Hendrica A J M; Tummers, Quirijn R J G; Mazar, Andrew P; Beekman, Freek J; Kuppen, Peter J K; van de Velde, Cornelis J H; Löwik, Clemens W G M; Frangioni, John V; van Leeuwen, Fijs W B; Sier, Cornelis F M; Vahrmeijer, Alexander L

    2015-06-10

    Pre- and intraoperative diagnostic techniques facilitating tumor staging are of paramount importance in colorectal cancer surgery. The urokinase receptor (uPAR) plays an important role in the development of cancer, tumor invasion, angiogenesis, and metastasis and over-expression is found in the majority of carcinomas. This study aims to develop the first clinically relevant anti-uPAR antibody-based imaging agent that combines nuclear (111In) and real-time near-infrared (NIR) fluorescent imaging (ZW800-1). Conjugation and binding capacities were investigated and validated in vitro using spectrophotometry and cell-based assays. In vivo, three human colorectal xenograft models were used including an orthotopic peritoneal carcinomatosis model to image small tumors. Nuclear and NIR fluorescent signals showed clear tumor delineation between 24h and 72h post-injection, with highest tumor-to-background ratios of 5.0 ± 1.3 at 72h using fluorescence and 4.2 ± 0.1 at 24h with radioactivity. 1-2 mm sized tumors could be clearly recognized by their fluorescent rim. This study showed the feasibility of an uPAR-recognizing multimodal agent to visualize tumors during image-guided resections using NIR fluorescence, whereas its nuclear component assisted in the pre-operative non-invasive recognition of tumors using SPECT imaging. This strategy can assist in surgical planning and subsequent precision surgery to reduce the number of incomplete resections. PMID:25895028

  19. Modelisation par elements finis du muscle strie

    NASA Astrophysics Data System (ADS)

    Leonard, Mathieu

    Ce present projet de recherche a permis. de creer un modele par elements finis du muscle strie humain dans le but d'etudier les mecanismes engendrant les lesions musculaires traumatiques. Ce modele constitue une plate-forme numerique capable de discerner l'influence des proprietes mecaniques des fascias et de la cellule musculaire sur le comportement dynamique du muscle lors d'une contraction excentrique, notamment le module de Young et le module de cisaillement de la couche de tissu conjonctif, l'orientation des fibres de collagene de cette membrane et le coefficient de poisson du muscle. La caracterisation experimentale in vitro de ces parametres pour des vitesses de deformation elevees a partir de muscles stries humains actifs est essentielle pour l'etude de lesions musculaires traumatiques. Le modele numerique developpe est capable de modeliser la contraction musculaire comme une transition de phase de la cellule musculaire par un changement de raideur et de volume a l'aide des lois de comportement de materiau predefinies dans le logiciel LS-DYNA (v971, Livermore Software Technology Corporation, Livermore, CA, USA). Le present projet de recherche introduit donc un phenomene physiologique qui pourrait expliquer des blessures musculaires courantes (crampes, courbatures, claquages, etc.), mais aussi des maladies ou desordres touchant le tissu conjonctif comme les collagenoses et la dystrophie musculaire. La predominance de blessures musculaires lors de contractions excentriques est egalement exposee. Le modele developpe dans ce projet de recherche met ainsi a l'avant-scene le concept de transition de phase ouvrant la porte au developpement de nouvelles technologies pour l'activation musculaire chez les personnes atteintes de paraplegie ou de muscles artificiels compacts pour l'elaboration de protheses ou d'exosquelettes. Mots-cles Muscle strie, lesion musculaire, fascia, contraction excentrique, modele par elements finis, transition de phase

  20. Evaluation of the PAR corneal topography system

    NASA Astrophysics Data System (ADS)

    Jindal, Prateek; Cheung, Susan; Pirouzian, Amir; Keates, Richard H.; Ren, Qiushi

    1995-05-01

    The purpose of this study was to evaluate the raster photogrammetry based Corneal Topography System by determining: inter-operator variability, reproducibility of images, effects of defocused and decentered images, and the precision of data at different optical zones. 4 human cadaver eyes were used to study the inter-operator variability. To study the reproducibility of images, 3 human cadaver eyes and a test surface doped with flourescine (provided by PAR Vision Systems Corporation) were focused and their images taken four successive times. Defocused and decentered images were taken of 4 human cadaver eyes and four times of the test surface mentioned above. The precision of defocused/decentered cadaver eyes was evaluated at the following optical zones: 3 mm, 4 mm, 5 mm, and 6 mm. All human cadaver eyes used in the above experiments had their epithelial layer removed before imaging. Average inter-operator variability was 0.06 D. In reproducibility attempts, there was an average deviation of 0.28 D for the human cadaver eyes and 0.04 D for the test surface. The defocused and decentered test surface gave an average deviation of 0.09 D. Defocused and decentered cadaver eyes resulted in an average deviation of 0.52 D, 0.37 D, 0.24 D, and 0.22 D at optical zones of 3 mm, 4 mm, 5 mm, and 6 mm, respectively. The imaging method employed by PAR Vision Systems Corporation virtually eliminates inter-operator variability. The PAR Corneal Topography System's clinical usefulness, however, could be improved by improving the reproducibility of images, decreasing the sensitivity to spatial alignment, and increasing accuracy over smaller optical zones.

  1. A Conserved Mode of Protein Recognition and Binding in a ParD−ParE Toxin−Antitoxin Complex

    SciTech Connect

    Dalton, Kevin M.; Crosson, Sean

    2010-05-06

    Toxin-antitoxin (TA) systems form a ubiquitous class of prokaryotic proteins with functional roles in plasmid inheritance, environmental stress response, and cell development. ParDE family TA systems are broadly conserved on plasmids and bacterial chromosomes and have been well characterized as genetic elements that promote stable plasmid inheritance. We present a crystal structure of a chromosomally encoded ParD-ParE complex from Caulobacter crescentus at 2.6 {angstrom} resolution. This TA system forms an {alpha}{sub 2}{beta}{sub 2} heterotetramer in the crystal and in solution. The toxin-antitoxin binding interface reveals extensive polar and hydrophobic contacts of ParD antitoxin helices with a conserved recognition and binding groove on the ParE toxin. A cross-species comparison of this complex structure with related toxin structures identified an antitoxin recognition and binding subdomain that is conserved between distantly related members of the RelE/ParE toxin superfamily despite a low level of overall primary sequence identity. We further demonstrate that ParD antitoxin is dimeric, stably folded, and largely helical when not bound to ParE toxin. Thus, the paradigmatic model in which antitoxin undergoes a disorder-to-order transition upon toxin binding does not apply to this chromosomal ParD-ParE TA system.

  2. A conserved mode of protein recognition and binding in a ParD-ParE toxin-antitoxin complex†

    PubMed Central

    Dalton, Kevin M.; Crosson, Sean

    2010-01-01

    Toxin-antitoxin (TA) systems form a ubiquitous class of prokaryotic proteins with functional roles in plasmid inheritance, environmental stress response, and cell development. ParDE-family TA systems are broadly conserved on plasmids and bacterial chromosomes, and have been well characterized as genetic elements that promote stable plasmid inheritance. We present a crystal structure of a chromosomally-encoded ParD-ParE complex from Caulobacter crescentus at 2.6 Å resolution. This TA system forms an α2β2 heterotetramer in the crystal and in solution. The toxin-antitoxin binding interface reveals extensive polar and hydrophobic contacts of ParD antitoxin helices with a conserved recognition and binding groove on the ParE toxin. A cross-species comparison of this complex structure with related toxin structures identified an antitoxin recognition and binding sub-domain that is conserved between distantly-related members of the RelE/ParE toxin superfamily despite low overall primary sequence identity. We further demonstrate that ParD antitoxin is dimeric, stably folded, and largely helical when not bound to ParE toxin. Thus, the paradigmatic model in which antitoxin undergoes a disorder-to-order transition upon toxin binding does not apply to this chromosomal ParD-ParE TA system. PMID:20143871

  3. Long pulse production from short pulses

    DOEpatents

    Toeppen, J.S.

    1994-08-02

    A method of producing a long output pulse from a short pump pulse is disclosed, using an elongated amplified fiber having a doped core that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding. A seed beam of the longer wavelength is injected into the core at one end of the fiber and a pump pulse of the shorter wavelength is injected into the cladding at the other end of the fiber. The counter-propagating seed beam and pump pulse will produce an amplified output pulse having a time duration equal to twice the transit time of the pump pulse through the fiber plus the length of the pump pulse. 3 figs.

  4. Long pulse production from short pulses

    DOEpatents

    Toeppen, John S.

    1994-01-01

    A method of producing a long output pulse (SA) from a short pump pulse (P), using an elongated amplified fiber (11) having a doped core (12) that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding 13. A seed beam (S) of the longer wavelength is injected into the core (12) at one end of the fiber (11) and a pump pulse (P) of the shorter wavelength is injected into the cladding (13) at the other end of the fiber (11). The counter-propagating seed beam (S) and pump pulse (P) will produce an amplified output pulse (SA) having a time duration equal to twice the transit time of the pump pulse (P) through the fiber (11) plus the length of the pump pulse (P).

  5. Historic macrophyte development in Par Pond

    SciTech Connect

    Grace, J.B.

    1985-08-01

    Aerial photographs from 1975, 1980, and 1983 were examined to evaluate the changes that have occurred in the wetland vegetation of Par Pond, a reactor-cooling reservoir. Evaluation of the aerial photographs was based on comparisons with ground-level vegetation maps made during July 1984. Comparisons of photographs from August and December of 1983 revealed the main seasonal change in the aerial coverage of wetland vegetation to be the wintertime loss of non-persistent emergent species such as Nelumbo lutea and Nymphaea odorata. Comparisons between September 1980 and August 1983 revealed that the lakeward extent of non-persistent macrophytes has increased by an average of 8.2 m, though not all sites have changed equally. For persistent macrophytes (principally Typha), the average increase in lakeward extent between December 1975 and August 1983 was 3.48 m. The extensive development of wetland vegetation in Par Pond as well as the substantial spread of vegetation over only a few years time indicates the high suitability of this habitat for the growth of wetland plants.

  6. A Par-1-Par-3-Centrosome Cell Polarity Pathway and Its Tuning for Isotropic Cell Adhesion.

    PubMed

    Jiang, Tao; McKinley, R F Andrew; McGill, Melanie A; Angers, Stephane; Harris, Tony J C

    2015-10-19

    To form regulated barriers between body compartments, epithelial cells polarize into apical and basolateral domains and assemble adherens junctions (AJs). Despite close links with polarity networks that generate single polarized domains, AJs distribute isotropically around the cell circumference for adhesion with all neighboring cells [1-3]. How AJs avoid the influence of polarity networks to maintain their isotropy has been unclear. In established epithelia, trans cadherin interactions could maintain AJ isotropy [4], but AJs are dynamic during epithelial development and remodeling [5, 6], and thus specific mechanisms may control their isotropy. In Drosophila, aPKC prevents hyper-polarization of junctions as epithelia develop from cellularization to gastrulation [7]. Here, we show that aPKC does so by inhibiting a positive feedback loop between Bazooka (Baz)/Par-3, a junctional organizer [5, 8-10], and centrosomes. Without aPKC, Baz and centrosomes lose their isotropic distributions and recruit each other to single plasma membrane (PM) domains. Surprisingly, our loss- and gain-of-function analyses show that the Baz-centrosome positive feedback loop is driven by Par-1, a kinase known to phosphorylate Baz and inhibit its basolateral localization [8, 11, 12]. We find that Par-1 promotes the positive feedback loop through both centrosome microtubule effects and Baz phosphorylation. Normally, aPKC attenuates the circuit by expelling Par-1 from the apical domain at gastrulation. The combination of local activation and global inhibition is a common polarization strategy [13-16]. Par-1 seems to couple both effects for a potent Baz polarization mechanism that is regulated for the isotropy of Baz and AJs around the cell circumference. PMID:26455305

  7. Controlling plasma channels through ultrashort laser pulse filamentation

    NASA Astrophysics Data System (ADS)

    Ionin, Andrey A.; Seleznev, Leonid V.; Sunchugasheva, Elena S.

    2013-10-01

    A review of studies fulfilled at the Lebedev Institute in collaboration with the Moscow State University and Institute of Atmospheric Optics in Tomsk (Siberia) on influence of various characteristics of ultrashort laser pulse on plasma channels formed under its filamentation is presented. Filamentation of high-power laser pulses with wavefront controlled by a deformable mirror, with cross-sections spatially formed by various diaphragms and with different wavelengths was experimentally and numerically studied. An application of plasma channels formed due to filamentation of ultrashort laser pulse including a train of such pulses for triggering and guiding electric discharge is discussed.

  8. 2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) BARRACKS WITH RADAR ATTACHED. - Nike Hercules Missile Battery Summit Site, Battery Control Administration & Barracks Building, Anchorage, Anchorage, AK

  9. Exploring intense attosecond pulses

    NASA Astrophysics Data System (ADS)

    Charalambidis, D.; Tzallas, P.; Benis, E. P.; Skantzakis, E.; Maravelias, G.; Nikolopoulos, L. A. A.; Peralta Conde, A.; Tsakiris, G. D.

    2008-02-01

    After introducing the importance of non-linear processes in the extreme-ultra-violet (XUV) spectral regime to the attosecond (asec) pulse metrology and time domain applications, we present two successfully implemented techniques with excellent prospects in generating intense asec pulse trains and isolated asec pulses, respectively. For the generation of pulse trains two-color harmonic generation is exploited. The interferometric polarization gating technique appropriate for the generation of intense isolated asec pulses is discussed and compared to other relevant approaches.

  10. Transcriptome profiling reveals links between ParS/ParR, MexEF-OprN, and quorum sensing in the regulation of adaptation and virulence in Pseudomonas aeruginosa

    PubMed Central

    2013-01-01

    Background The ParS/ParR two component regulatory system plays critical roles for multidrug resistance in Pseudomonas aeruginosa. It was demonstrated that in the presence of antimicrobials, ParR enhances bacterial survival by distinct mechanisms including activation of the mexXY efflux genes, enhancement of lipopolysaccharide modification through the arn operon, and reduction of the expression of oprD porin. Results In this study, we report on transcriptomic analyses of P. aeruginosa PAO1 wild type and parS and parR mutants growing in a defined minimal medium. Our transcriptomic analysis provides the first estimates of transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to the known effects on drug resistance genes, transcript abundances of the quorum sensing genes (rhlIR and pqsABCDE-phnAB) were higher in both parS and parR mutants. In accordance with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of the par genes also led to increased phenazine production and swarming motility, consistent with the up-regulation of the phenazine and rhamnolipid biosynthetic genes, respectively. Conclusion Our results link the ParS/ParR two component signal transduction system to MexEF-OprN and quorum sensing systems in P. aeruginosa. These results expand our understanding of the roles of the ParS/ParR system in the regulation of gene expression in P. aeruginosa, especially in the absence of antimicrobials. PMID:24034668

  11. Multifunctional pulse sequence generator for pulse NMR

    NASA Astrophysics Data System (ADS)

    Wang, Dongsheng

    1988-06-01

    A new multifunctional pulse sequence generator has been designed and constructed. It can conveniently generate various pulse sequences used in nuclear-magnetic resonance (NMR) to measure the spin-lattice relaxation time T1, the spin-spin relaxation time T2, and the spin-locking relaxation time T1 ρ. It can also be used in pulse Fourier transform NMR and double resonance. The intervals of pulses can increase automatically with sequence repetitions and the generator can be used in two-dimensional spectrum measurement and spin-density imaging research. The sequences can be generated through four different triggering methods and there are two synchronous pulse outputs and fifteen auxiliary pulse outputs, so the generator can be conveniently interfaced with a computer or other instruments. The circuitry, functions, and features of the generator are described in this article.

  12. Taare Zameen Par and dyslexic savants.

    PubMed

    Chakravarty, Ambar

    2009-04-01

    The film Taare Zameen Par (Stars upon the Ground) portrays the tormented life at school and at home of a child with dyslexia and his eventual success after his artistic talents are discovered by his art teacher at the boarding school. The film hints at a curious neurocognitive phenomenon of creativity in the midst of language disability, as exemplified in the lives of people like Leonardo da Vinci and Albert Einstein, both of whom demonstrated extraordinary creativity even though they were probably affected with developmental learning disorders. It has been hypothesized that a developmental delay in the dominant hemisphere most likely 'disinhibits' the nondominant parietal lobe, unmasking talents-artistic or otherwise-in some such individuals. It has been suggested that, in remedial training, children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to the usual overemphasis on the correction of the disturbed coded symbol operations. PMID:20142854

  13. Taare Zameen Par and dyslexic savants

    PubMed Central

    Chakravarty, Ambar

    2009-01-01

    The film Taare Zameen Par (Stars upon the Ground) portrays the tormented life at school and at home of a child with dyslexia and his eventual success after his artistic talents are discovered by his art teacher at the boarding school. The film hints at a curious neurocognitive phenomenon of creativity in the midst of language disability, as exemplified in the lives of people like Leonardo da Vinci and Albert Einstein, both of whom demonstrated extraordinary creativity even though they were probably affected with developmental learning disorders. It has been hypothesized that a developmental delay in the dominant hemisphere most likely ‘disinhibits’ the nondominant parietal lobe, unmasking talents—artistic or otherwise—in some such individuals. It has been suggested that, in remedial training, children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to the usual overemphasis on the correction of the disturbed coded symbol operations. PMID:20142854

  14. Biased signaling: potential agonist and antagonist of PAR2.

    PubMed

    Kakarala, Kavita Kumari; Jamil, Kaiser

    2016-06-01

    Protease activated receptor 2 (PAR2) has emerged as one of the promising therapeutic targets to inhibit rapidly metastasizing breast cancer cells. However, its elusive molecular mechanism of activation and signaling has made it a difficult target for drug development. In this study, in silico methods were used to unfold PAR2 molecular mechanism of signaling based on the concept of GPCR receptor plasticity. Although, there are no conclusive evidences of the presence of specific endogenous ligands for PAR2, the efficacy of synthetic agonist and antagonist in PAR2 signaling has opened up the possibilities of ligand-mediated signaling. Furthermore, it has been proved that ligands specific for one GPCR can induce signaling in GPCRs belonging to other subfamilies. Therefore, the aim of this study was to identify potential agonists and antagonists from the GPCR ligand library (GLL), which may induce biased signaling in PAR2 using the concept of existence of multiple ligand-stabilized receptor conformations. The results of our in silico study suggest that PAR2 may show biased signaling mainly with agonists of serotonin type 1, β-adrenergic type 1,3 and antagonists of substance K (NK1), serotonin type 2, dopamine type 4, and thromboxane receptors. Further, this study also throws light on the putative ligand-specific conformations of PAR2. Thus, the results of this study provide structural insights to putative conformations of PAR2 and also gives initial clues to medicinal chemists for rational drug design targeting this challenging receptor. PMID:26295578

  15. DIFFERENTIAL PULSE HEIGHT DISCRIMINATOR

    DOEpatents

    Test, L.D.

    1958-11-11

    Pulse-height discriminators are described, specifically a differential pulse-height discriminator which is adapted to respond to pulses of a band of amplitudes, but to reject pulses of amplitudes greater or less than tbe preselected band. In general, the discriminator includes a vacuum tube having a plurality of grids adapted to cut off plate current in the tube upon the application of sufficient negative voltage. One grid is held below cutoff, while a positive pulse proportional to the amplltude of each pulse is applled to this grid. Another grid has a negative pulse proportional to the amplitude of each pulse simultaneously applied to it. With this arrangement the tube will only pass pulses which are of sufficlent amplitude to counter the cutoff bias but not of sufficlent amplitude to cutoff the tube.

  16. Proteases in agricultural dust induce lung inflammation through PAR-1 and PAR-2 activation.

    PubMed

    Romberger, Debra J; Heires, Art J; Nordgren, Tara M; Souder, Chelsea P; West, William; Liu, Xiang-de; Poole, Jill A; Toews, Myron L; Wyatt, Todd A

    2015-08-15

    Workers exposed to aerosolized dust present in concentrated animal feeding operations (CAFOs) are susceptible to inflammatory lung diseases, such as chronic obstructive pulmonary disease. Extracts of dust collected from hog CAFOs [hog dust extract (HDE)] are potent stimulators of lung inflammatory responses in several model systems. The observation that HDE contains active proteases prompted the present study, which evaluated the role of CAFO dust proteases in lung inflammatory processes and tested whether protease-activated receptors (PARs) are involved in the signaling pathway for these events. We hypothesized that the damaging proinflammatory effect of HDE is due, in part, to the proteolytic activation of PARs, and inhibiting the proteases in HDE or disrupting PAR activation would attenuate HDE-mediated inflammatory indexes in bronchial epithelial cells (BECs), in mouse lung slices in vitro, and in a murine in vivo exposure model. Human BECs and mouse lung slice cultures stimulated with 5% HDE released significantly more of each of the cytokines measured (IL-6, IL-8, TNF-α, keratinocyte-derived chemokine/CXC chemokine ligand 1, and macrophage inflammatory protein-2/CXC chemokine ligand 2) than controls, and these effects were markedly diminished by protease inhibition. Inhibition of PARs also blunted the HDE-induced cytokine release from BECs. In addition, protease depletion inhibited HDE-induced BEC intracellular PKCα and PKCε activation. C57BL/6J mice administered 12.5% HDE intranasally, either once or daily for 3 wk, exhibited increased total cellular and neutrophil influx, bronchial alveolar fluid inflammatory cytokines, lung histopathology, and inflammatory scores compared with mice receiving protease-depleted HDE. These data suggest that proteases in dust from CAFOs are important mediators of lung inflammation, and these proteases and their receptors may provide novel targets for therapeutic intervention in CAFO dust-induced airways disease. PMID

  17. Cancer-selective apoptosis by tumor suppressor par-4.

    PubMed

    Hebbar, Nikhil; Shrestha-Bhattarai, Tripti; Rangnekar, Vivek M

    2014-01-01

    Tumor suppressor genes play an important role in preventing neoplastic transformation and maintaining normal tissue homeostasis. Par-4 is one such tumor suppressor which is unique in its ability to selectively induce apoptosis in cancer cells while leaving the normal cells unaffected. The cancer cell specific activity of Par-4 is elicited through intracellular as well as extracellular mechanisms. Intracellularly Par-4 acts through the inhibition of pro-survival pathways and activation of Fas mediated apoptosis whereas extracellular (secreted Par-4) acts by binding to cell surface GRP78 leading to activation of the extrinsic apoptotic pathway. Many studies have highlighted the importance of Par-4 not only in preventing cancer development/recurrence but also as a promising anticancer therapeutic agent. PMID:25001535

  18. PAR-3 and PAR-1 Inhibit LET-99 Localization to Generate a Cortical Band Important for Spindle Positioning in Caenorhabditis elegans Embryos

    PubMed Central

    Wu, Jui-Ching

    2007-01-01

    The conserved PAR proteins are localized in asymmetric cortical domains and are required for the polarized localization of cell fate determinants in many organisms. In Caenorhabditis elegans embryos, LET-99 and G protein signaling act downstream of the PARs to regulate spindle positioning and ensure asymmetric division. PAR-3 and PAR-2 localize LET-99 to a posterior cortical band through an unknown mechanism. Here we report that LET-99 asymmetry depends on cortically localized PAR-1 and PAR-4 but not on cytoplasmic polarity effectors. In par-1 and par-4 embryos, LET-99 accumulates at the entire posterior cortex, but remains at low levels at the anterior cortex occupied by PAR-3. Further, PAR-3 and PAR-1 have graded cortical distributions with the highest levels at the anterior and posterior poles, respectively, and the lowest levels of these proteins correlate with high LET-99 accumulation. These results suggest that PAR-3 and PAR-1 inhibit the localization of LET-99 to generate a band pattern. In addition, PAR-1 kinase activity is required for the inhibition of LET-99 localization, and PAR-1 associates with LET-99. Finally, examination of par-1 embryos suggests that the banded pattern of LET-99 is critical for normal posterior spindle displacement and to prevent spindle misorientation caused by cell shape constraints. PMID:17761536

  19. Recombination in the Human Pseudoautosomal Region PAR1

    PubMed Central

    Hinch, Anjali G.; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R.

    2014-01-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  20. Recombination in the human Pseudoautosomal region PAR1.

    PubMed

    Hinch, Anjali G; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R

    2014-07-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  1. Circulating suPAR in Two Cohorts of Primary FSGS

    PubMed Central

    Wei, Changli; Trachtman, Howard; Li, Jing; Dong, Chuanhui; Friedman, Aaron L.; Gassman, Jennifer J.; McMahan, June L.; Radeva, Milena; Heil, Karsten M.; Trautmann, Agnes; Anarat, Ali; Emre, Sevinc; Ghiggeri, Gian M.; Ozaltin, Fatih; Haffner, Dieter; Gipson, Debbie S.; Kaskel, Frederick; Fischer, Dagmar-Christiane; Schaefer, Franz

    2012-01-01

    Overexpression of soluble urokinase receptor (suPAR) causes pathology in animal models similar to primary FSGS, and one recent study demonstrated elevated levels of serum suPAR in patients with the disease. Here, we analyzed circulating suPAR levels in two cohorts of children and adults with biopsy-proven primary FSGS: 70 patients from the North America–based FSGS clinical trial (CT) and 94 patients from PodoNet, the Europe-based consortium studying steroid-resistant nephrotic syndrome. Circulating suPAR levels were elevated in 84.3% and 55.3% of patients with FSGS patients in the CT and PodoNet cohorts, respectively, compared with 6% of controls (P<0.0001); inflammation did not account for this difference. Multiple regression analysis suggested that lower suPAR levels associated with higher estimated GFR, male sex, and treatment with mycophenolate mofetil. In the CT cohort, there was a positive association between the relative reduction of suPAR after 26 weeks of treatment and reduction of proteinuria, with higher odds for complete remission (P=0.04). In the PodoNet cohort, patients with an NPHS2 mutation had higher suPAR levels than those without a mutation. In conclusion, suPAR levels are elevated in geographically and ethnically diverse patients with FSGS and do not reflect a nonspecific proinflammatory milieu. The associations between a change in circulating suPAR with different therapeutic regimens and with remission support the role of suPAR in the pathogenesis of FSGS. PMID:23138488

  2. Circulating suPAR in two cohorts of primary FSGS.

    PubMed

    Wei, Changli; Trachtman, Howard; Li, Jing; Dong, Chuanhui; Friedman, Aaron L; Gassman, Jennifer J; McMahan, June L; Radeva, Milena; Heil, Karsten M; Trautmann, Agnes; Anarat, Ali; Emre, Sevinc; Ghiggeri, Gian M; Ozaltin, Fatih; Haffner, Dieter; Gipson, Debbie S; Kaskel, Frederick; Fischer, Dagmar-Christiane; Schaefer, Franz; Reiser, Jochen

    2012-12-01

    Overexpression of soluble urokinase receptor (suPAR) causes pathology in animal models similar to primary FSGS, and one recent study demonstrated elevated levels of serum suPAR in patients with the disease. Here, we analyzed circulating suPAR levels in two cohorts of children and adults with biopsy-proven primary FSGS: 70 patients from the North America-based FSGS clinical trial (CT) and 94 patients from PodoNet, the Europe-based consortium studying steroid-resistant nephrotic syndrome. Circulating suPAR levels were elevated in 84.3% and 55.3% of patients with FSGS patients in the CT and PodoNet cohorts, respectively, compared with 6% of controls (P<0.0001); inflammation did not account for this difference. Multiple regression analysis suggested that lower suPAR levels associated with higher estimated GFR, male sex, and treatment with mycophenolate mofetil. In the CT cohort, there was a positive association between the relative reduction of suPAR after 26 weeks of treatment and reduction of proteinuria, with higher odds for complete remission (P=0.04). In the PodoNet cohort, patients with an NPHS2 mutation had higher suPAR levels than those without a mutation. In conclusion, suPAR levels are elevated in geographically and ethnically diverse patients with FSGS and do not reflect a nonspecific proinflammatory milieu. The associations between a change in circulating suPAR with different therapeutic regimens and with remission support the role of suPAR in the pathogenesis of FSGS. PMID:23138488

  3. Laser-generated ultrasonic pulse shapes at solid wedges.

    PubMed

    Pupyrev, Pavel D; Lomonosov, Alexey M; Mayer, Andreas P

    2016-08-01

    Laser pulses focused near the tip of an elastic wedge generate acoustic waves guided at its apex. The shapes of the acoustic wedge wave pulses depend on the energy and the profile of the exciting laser pulse and on the anisotropy of the elastic medium the wedge is made of. Expressions for the acoustic pulse shapes have been derived in terms of the modal displacement fields of wedge waves for laser excitation in the thermo-elastic regime and for excitation via a pressure pulse exerted on the surface. The physical quantity considered is the local inclination of a surface of the wedge, which is measured optically by laser-probe-beam deflection. Experimental results on pulse shapes in the thermo-elastic regime are presented and confirmed by numerical calculations. They pertain to an isotropic sharp-angle wedge with two wedge-wave branches and to a non-reciprocity phenomenon at rectangular silicon edges. PMID:27135188

  4. Laser pulse stacking method

    DOEpatents

    Moses, Edward I.

    1992-01-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter.

  5. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  6. Laser pulse stacking method

    DOEpatents

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  7. Condensation and localization of the partitioning protein ParB on the bacterial chromosome.

    PubMed

    Broedersz, Chase P; Wang, Xindan; Meir, Yigal; Loparo, Joseph J; Rudner, David Z; Wingreen, Ned S

    2014-06-17

    The ParABS system mediates chromosome segregation and plasmid partitioning in many bacteria. As part of the partitioning mechanism, ParB proteins form a nucleoprotein complex at parS sites. The biophysical basis underlying ParB-DNA complex formation and localization remains elusive. Specifically, it is unclear whether ParB spreads in 1D along DNA or assembles into a 3D protein-DNA complex. We show that a combination of 1D spreading bonds and a single 3D bridging bond between ParB proteins constitutes a minimal model for a condensed ParB-DNA complex. This model implies a scaling behavior for ParB-mediated silencing of parS-flanking genes, which we confirm to be satisfied by experimental data from P1 plasmids. Furthermore, this model is consistent with experiments on the effects of DNA roadblocks on ParB localization. Finally, we show experimentally that a single parS site is necessary and sufficient for ParB-DNA complex formation in vivo. Together with our model, this suggests that ParB binding to parS triggers a conformational switch in ParB that overcomes a nucleation barrier. Conceptually, the combination of spreading and bridging bonds in our model provides a surface tension ensuring the condensation of the ParB-DNA complex, with analogies to liquid-like compartments such as nucleoli in eukaryotes. PMID:24927534

  8. SPRY1 promotes the degradation of uPAR and inhibits uPAR-mediated cell adhesion and proliferation

    PubMed Central

    Liu, Xiufeng; Lan, Yan; Zhang, Di; Wang, Kai; Wang, Yao; Hua, Zi-Chun

    2014-01-01

    Urokinase plasminogen activator receptor (uPAR) is a GPI anchored cell surface protein that is closely associated with invasion, migration, and metastasis of cancer cells. Many functional extracellular proteins and transmembrane receptors interact with uPAR. However, few studies have examined the association of uPAR with cytoplasm proteins. We previously used yeast two-hybrid screening to isolate several novel uPAR-interacting cytoplasmic proteins, including Sprouty1 (SPRY1), an inhibitor of the (Ras-mitogen-activated protein kinase) MAPK pathway. In this study, we show that SPRY1 interacts with uPAR and directs it toward lysosomal-mediated degradation. Overexpression of SPRY1 decreased the cell surface and cytoplasmic uPAR protein level. Moreover, SPRY1 overexpression augmented uPAR-induced cell adhesion to vitronectin as well as proliferation of cancer cells. Our results also further support the critical role of SPRY1 contribution to tumor growth. In a subcutaneous tumor model, overexpression of SPRY1 in HCT116 or A549 xenograft in athymic nude mice led to great suppression of tumor growth. These results show that SPRY1 may affect tumor cell function through direct interaction with uPAR and promote its lysosomal degradation. PMID:25520860

  9. Pulse to pulse klystron diagnosis system

    SciTech Connect

    Nowak, J.; Davidson, V.; Genova, L.; Johnson, R.; Reagan, D.

    1981-03-01

    This report describes a system used to study the behavior of SLAC high powered klystrons operating with a twice normal pulse width of 5 ..mu..s. At present, up to eight of the klystrons installed along the accelerator can be operated with long pulses and monitored by this system. The report will also discuss some of the recent findings and investigations.

  10. Traitement des fractures des plateaux externes par vissage percutané assisté par arthroscopie

    PubMed Central

    Abouchane, Merouane; Belmoubarik, Amine; Benameur, Hamza; Haddoun, Ahmed Reda; Nechad, Mohammed

    2015-01-01

    Le but de notre étude est d'évaluer les résultats de fractures des plateaux tibiaux externes traitées par ostéosynthèse percutanée assistée par arthroscopie. Dix patients (8 hommes et 2 femmes) de 32 ans en moyenne ont subi cette intervention afin de réparer des fractures des plateaux tibiaux Schatzker I-III. Après avoir appliqué un garrot pneumatique, nous avons réduit et fixé la fracture au moyen de vis cannelées souschondrales. Lésions associées retrouvent deux lésions partielles du ménisque externe ont été retrouvé, traitées par résection partielle. Une orthèse de genou été de mise à but antalgique et protectrice pendant six semaines avec béquillage et interdiction de l'appui pour une durée de douze semaines avec reprise d'appui partiel au delà. La durée d'hospitalisation été d'une moyenne de cinq jours. La rééducation passive a été commence le lendemain de l'intervention et continuait dans chez un kinésithérapeute à la sortie du patient du service. Le suivi été à J7, J15, 1mois, 3mois, 6 mois puis tous les 6 mois. Neuf de nos patients ont été revu régulièrement sauf un perdu de vue. Le recul moyen de notre série été de 16 mois (10 et 24 mois). Le score de Lysholm a été utilisé pour évaluer les résultats cliniques chez nos neuf patients: excellent chez trois patients bons chez trois moyen chez un seul et mauvais chez deux patients. Tous nos neuf patients ont consolidé (figure 10 contrôle scopique d un article). Aucune gonarthrose n'a été note chez nos neuf patients due essentiellement au recul moyen faible de 16 mois. Le traitement des fractures des plateaux tibiaux externes assisté par arthroscopie produit des résultats satisfaisants et peut être accepté comme solution de rechange efficace au traitement des fractures des plateaux tibiaux causées par un choc de faible énergie. PMID:26587137

  11. Pulse dynamics in an unstable medium

    SciTech Connect

    Balmforth, N.J.; Ierley, G.R.; Worthing, R.

    1995-05-01

    A study is presented of a one-dimensional, nonlinear partial differential equation that describes evolution of dispersive, long-wave instability. The solutions, under certain specific conditions, take the form of trains of well-separated pulses. The dynamics of such patterns of pulses is investigated using singular perturbation theory and with numerical simulation. These tools permit the formulation of a theory of pulse interaction, and enable the mapping out of the range of behavior in parameter space. There are regimes in which steady trains form; such states can be studied with the asymptotic, pulse-interaction theory. In other regimes, pulse trains are unstable to global, wave-like modes or its radiation. This can precipitate more violent phenomena involving pulse creation, or generate periodic states which may follow Shil`nikov`s route to temporal chaos. The asymptotic theory is generalized lo take some account of radiative dynamics. In the limit of small dispersion, steady trains largely cease to exist; the system follows various pathways to temporal complexity and typical-bifurcation sequences are sketched out. The investigation guides us to a critical appraisal of the asymptotic theory and uncovers the wealth of different types of behavior present in the system.

  12. Control of cleavage spindle orientation in Caenorhabditis elegans: The role of the genes par-2 and par-3

    SciTech Connect

    Cheng, N.N.; Kirby, C.M.; Kemphues, K.J.

    1995-02-01

    Polarized asymmetric divisions play important roles in the development of plants and animals. The first two embryonic cleavages of Caenorhabditis elegans provide an opportunity to study the mechanisms controlling polarized asymmetric divisions. The first cleavage is unequal, producing daughters with different sizes and fates. The daughter blastomeres divide with different orientations at the second cleavage; the anterior blastomere divides equally across the long axis of the egg, whereas the posterior blastomere divides unequally along the long axis. We report here the results of our analysis of the genes par-2 and par-3 with respect to their contribution to the polarity of these divisions. Strong loss-of-function mutations in both genes lead to an equal first cleavage and an altered second cleavage. Interestingly, the mutations exhibit striking gene-specific differences at the second cleavage. The par-2 mutations lead to transverse spindle orientations in both blastomeres, whereas par-3 mutations lead to longitudinal spindle orientations in both blastomeres. The spindle orientation defects correlate with defects in centrosome movements during both the first and the second cell cycle. Temperature shift experiments with par-2 (it5ts) indicate that the par-2(+) activity is not required after the two-cell stage. Analysis of double mutants shows that par-3 is epistatic to par-2. We propose a model wherein par-2(+) and par-3(+) act in concert during the first cell cycle to affect asymmetric modification of the cytoskeleton. This polar modification leads to different behaviors of centrosomes in the anterior and posterior and leads ultimately to blastomere-specific spindle orientations at the second cleavage. 44 refs., 5 figs., 5 tabs.

  13. Radial pulse (image)

    MedlinePlus

    ... heart. The arteries are the vessels with the "pulse", a rhythmic pushing of the blood in the ... a refilling of the heart chamber. To determine heart rate, one feels the beats at a pulse point ...

  14. Wrist pulse (image)

    MedlinePlus

    To measure the pulse at the wrist, place the index and middle finger over the underside of the opposite wrist, below the base ... firmly with flat fingers until you feel the pulse in the radial artery.

  15. Recommendations by health organizations for pulse consumption.

    PubMed

    Leterme, Pascal

    2002-12-01

    The present paper aims to study why and how health organizations recommend the consumption of pulses such as beans, chickpeas or lentils. Although it is recognized that frequent pulse consumption may reduce serum cholesterol levels and helps reduce risks of coronary heart disease and diabetes, these advantages are scarcely mentioned by health-promoting associations, i.e. vegetarians and organizations helping people to reduce the risks for chronic diseases. Pulses, especially common beans, are rather considered as whole grains that provide plenty of proteins, starch, dietary fibres, minerals and vitamins. Many organizations refer to the food guide pyramid to advise their members, and place beans either in the third part, together with meat, in the second one with fruits and vegetables, or in the bottom part with starchy foods. Whatever their place, they have acquired the status of staple food for anyone who wants to eat a healthy diet. PMID:12498622

  16. Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Hou, Guangjin; Lu, Xingyu; Vega, Alexander J.; Polenova, Tatyana

    2014-09-01

    We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear 1H-X (X = 13C, 15N, 31P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the 1H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the 1H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from 1H chemical shift anisotropy, while keeping the 1H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [15N]-N-acetyl-valine and [U-13C,15N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate 1H-15N dipolar couplings in the context of 3D experiments is presented on U-13C,15N-enriched dynein light chain protein LC8.

  17. Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy

    SciTech Connect

    Hou, Guangjin E-mail: tpolenov@udel.edu; Lu, Xingyu E-mail: lexvega@comcast.net; Vega, Alexander J. E-mail: lexvega@comcast.net; Polenova, Tatyana E-mail: tpolenov@udel.edu

    2014-09-14

    We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear {sup 1}H-X (X = {sup 13}C, {sup 15}N, {sup 31}P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the {sup 1}H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the {sup 1}H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from {sup 1}H chemical shift anisotropy, while keeping the {sup 1}H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [{sup 15}N]-N-acetyl-valine and [U-{sup 13}C,{sup 15}N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate {sup 1}H-{sup 15}N dipolar couplings in the context of 3D experiments is presented on U-{sup 13}C,{sup 15}N-enriched dynein light chain protein LC8.

  18. Alternate drop pulse polarography

    USGS Publications Warehouse

    Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

    1976-01-01

    The new technique of alternate drop pulse polarography is presented. An experimental evaluation of alternate drop pulse polarography shows complete compensation of the capacitative background due to drop expansion. The capillary response phenomenon was studied in the absence of faradaic reaction and the capillary response current was found to depend on the pulse width to the -0.72 power. Increased signal-to-noise ratios were obtained using alternate drop pulse polarography at shorter drop times.

  19. Electrical pulse generator

    DOEpatents

    Norris, Neil J.

    1979-01-01

    A technique for generating high-voltage, wide dynamic range, shaped electrical pulses in the nanosecond range. Two transmission lines are coupled together by resistive elements distributed along the length of the lines. The conductance of each coupling resistive element as a function of its position along the line is selected to produce the desired pulse shape in the output line when an easily produced pulse, such as a step function pulse, is applied to the input line.

  20. Optically pulsed electron accelerator

    DOEpatents

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  1. Optically pulsed electron accelerator

    DOEpatents

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  2. Constant potential pulse polarography

    USGS Publications Warehouse

    Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

    1976-01-01

    The new technique of constant potential pulse polarography, In which all pulses are to be the same potential, is presented theoretically and evaluated experimentally. The response obtained is in the form of a faradaic current wave superimposed on a constant capacitative component. Results obtained with a computer-controlled system exhibit a capillary response current similar to that observed In normal pulse polarography. Calibration curves for Pb obtained using a modified commercial pulse polarographic instrument are in good accord with theoretical predictions.

  3. Poly(ADP-ribose) (PAR) polymer is a death signal

    PubMed Central

    Andrabi, Shaida A.; Kim, No Soo; Yu, Seong-Woon; Wang, Hongmin; Koh, David W.; Sasaki, Masayuki; Klaus, Judith A.; Otsuka, Takashi; Zhang, Zhizheng; Koehler, Raymond C.; Hurn, Patricia D.; Poirier, Guy G.; Dawson, Valina L.; Dawson, Ted M.

    2006-01-01

    Excessive activation of the nuclear enzyme, poly(ADP-ribose) polymerase-1 (PARP-1) plays a prominent role in various of models of cellular injury. Here, we identify poly(ADP-ribose) (PAR) polymer, a product of PARP-1 activity, as a previously uncharacterized cell death signal. PAR polymer is directly toxic to neurons, and degradation of PAR polymer by poly(ADP-ribose) glycohydrolase (PARG) or phosphodiesterase 1 prevents PAR polymer-induced cell death. PARP-1-dependent, NMDA excitotoxicity of cortical neurons is reduced by neutralizing antibodies to PAR and by overexpression of PARG. Neuronal cultures with reduced levels of PARG are more sensitive to NMDA excitotoxicity than WT cultures. Transgenic mice overexpressing PARG have significantly reduced infarct volumes after focal ischemia. Conversely, mice with reduced levels of PARG have significantly increased infarct volumes after focal ischemia compared with WT littermate controls. These results reveal PAR polymer as a signaling molecule that induces cell death and suggests that interference with PAR polymer signaling may offer innovative therapeutic approaches for the treatment of cellular injury. PMID:17116882

  4. Two-pulse ionization injection into quasilinear laser wakefields.

    PubMed

    Bourgeois, N; Cowley, J; Hooker, S M

    2013-10-11

    We describe a scheme for controlling electron injection into the quasilinear wakefield driven by a guided drive pulse via ionization of a dopant species by a collinear injection laser pulse with a short Rayleigh range. The scheme is analyzed by particle-in-cell simulations which show controlled injection and acceleration of electrons to an energy of 370 MeV, a relative energy spread of 2%, and a normalized transverse emittance of 2.0 μm. PMID:24160608

  5. COATING ALTERNATIVES GUIDE (CAGE) USER'S GUIDE

    EPA Science Inventory

    The guide provides instructions for using the Coating Alternatives GuidE (CAGE) software program, version 1.0. It assumes that the user is familiar with the fundamentals of operating an IBM-compatible personal computer (PC) under the Microsoft disk operating system (MS-DOS). CAGE...

  6. Protease-Activated Receptor (PAR)2, but Not PAR1, Is Involved in Collateral Formation and Anti-Inflammatory Monocyte Polarization in a Mouse Hind Limb Ischemia Model

    PubMed Central

    Nossent, Anne Yael; van Oeveren-Rietdijk, Annemarie M.; de Vries, Margreet R.; Spek, C. Arnold; van Zonneveld, Anton Jan; Reitsma, Pieter H.; Hamming, Jaap F.; de Boer, Hetty C.; Versteeg, Henri H.; Quax, Paul H. A.

    2013-01-01

    Aims In collateral development (i.e. arteriogenesis), mononuclear cells are important and exist as a heterogeneous population consisting of pro-inflammatory and anti-inflammatory/repair-associated cells. Protease-activated receptor (PAR)1 and PAR2 are G-protein-coupled receptors that are both expressed by mononuclear cells and are involved in pro-inflammatory reactions, while PAR2 also plays a role in repair-associated responses. Here, we investigated the physiological role of PAR1 and PAR2 in arteriogenesis in a murine hind limb ischemia model. Methods and Results PAR1-deficient (PAR1-/-), PAR2-deficient (PAR2-/-) and wild-type (WT) mice underwent femoral artery ligation. Laser Doppler measurements revealed reduced post-ischemic blood flow recovery in PAR2-/- hind limbs when compared to WT, while PAR1-/- mice were not affected. Upon ischemia, reduced numbers of smooth muscle actin (SMA)-positive collaterals and CD31-positive capillaries were found in PAR2-/- mice when compared to WT mice, whereas these parameters in PAR1-/- mice did not differ from WT mice. The pool of circulating repair-associated (Ly6C-low) monocytes and the number of repair-associated (CD206-positive) macrophages surrounding collaterals in the hind limbs were increased in WT and PAR1-/- mice, but unaffected in PAR2-/- mice. The number of repair-associated macrophages in PAR2-/- hind limbs correlated with CD11b- and CD115-expression on the circulating monocytes in these animals, suggesting that monocyte extravasation and M-CSF-dependent differentiation into repair-associated cells are hampered. Conclusion PAR2, but not PAR1, is involved in arteriogenesis and promotes the repair-associated response in ischemic tissues. Therefore, PAR2 potentially forms a new pro-arteriogenic target in coronary artery disease (CAD) patients. PMID:23637930

  7. Novel Role for Proteinase-activated Receptor 2 (PAR2) in Membrane Trafficking of Proteinase-activated Receptor 4 (PAR4)*

    PubMed Central

    Cunningham, Margaret R.; McIntosh, Kathryn A.; Pediani, John D.; Robben, Joris; Cooke, Alexandra E.; Nilsson, Mary; Gould, Gwyn W.; Mundell, Stuart; Milligan, Graeme; Plevin, Robin

    2012-01-01

    Proteinase-activated receptors 4 (PAR4) is a class A G protein-coupled receptor (GPCR) recognized through the ability of serine proteases such as thrombin and trypsin to mediate receptor activation. Due to the irreversible nature of activation, a fresh supply of receptor is required to be mobilized to the cell surface for responsiveness to agonist to be sustained. Unlike other PAR subtypes, the mechanisms regulating receptor trafficking of PAR4 remain unknown. Here, we report novel features of the intracellular trafficking of PAR4 to the plasma membrane. PAR4 was poorly expressed at the plasma membrane and largely retained in the endoplasmic reticulum (ER) in a complex with the COPI protein subunit β-COP1. Analysis of the PAR4 protein sequence identified an arginine-based (RXR) ER retention sequence located within intracellular loop-2 (R183AR → A183AA), mutation of which allowed efficient membrane delivery of PAR4. Interestingly, co-expression with PAR2 facilitated plasma membrane delivery of PAR4, an effect produced through disruption of β-COP1 binding and facilitation of interaction with the chaperone protein 14-3-3ζ. Intermolecular FRET studies confirmed heterodimerization between PAR2 and PAR4. PAR2 also enhanced glycosylation of PAR4 and activation of PAR4 signaling. Our results identify a novel regulatory role for PAR2 in the anterograde traffic of PAR4. PAR2 was shown to both facilitate and abrogate protein interactions with PAR4, impacting upon receptor localization and cell signal transduction. This work is likely to impact markedly upon the understanding of the receptor pharmacology of PAR4 in normal physiology and disease. PMID:22411985

  8. Novel role for proteinase-activated receptor 2 (PAR2) in membrane trafficking of proteinase-activated receptor 4 (PAR4).

    PubMed

    Cunningham, Margaret R; McIntosh, Kathryn A; Pediani, John D; Robben, Joris; Cooke, Alexandra E; Nilsson, Mary; Gould, Gwyn W; Mundell, Stuart; Milligan, Graeme; Plevin, Robin

    2012-05-11

    Proteinase-activated receptors 4 (PAR(4)) is a class A G protein-coupled receptor (GPCR) recognized through the ability of serine proteases such as thrombin and trypsin to mediate receptor activation. Due to the irreversible nature of activation, a fresh supply of receptor is required to be mobilized to the cell surface for responsiveness to agonist to be sustained. Unlike other PAR subtypes, the mechanisms regulating receptor trafficking of PAR(4) remain unknown. Here, we report novel features of the intracellular trafficking of PAR(4) to the plasma membrane. PAR(4) was poorly expressed at the plasma membrane and largely retained in the endoplasmic reticulum (ER) in a complex with the COPI protein subunit β-COP1. Analysis of the PAR(4) protein sequence identified an arginine-based (RXR) ER retention sequence located within intracellular loop-2 (R(183)AR → A(183)AA), mutation of which allowed efficient membrane delivery of PAR(4). Interestingly, co-expression with PAR(2) facilitated plasma membrane delivery of PAR(4), an effect produced through disruption of β-COP1 binding and facilitation of interaction with the chaperone protein 14-3-3ζ. Intermolecular FRET studies confirmed heterodimerization between PAR(2) and PAR(4). PAR(2) also enhanced glycosylation of PAR(4) and activation of PAR(4) signaling. Our results identify a novel regulatory role for PAR(2) in the anterograde traffic of PAR(4). PAR(2) was shown to both facilitate and abrogate protein interactions with PAR(4), impacting upon receptor localization and cell signal transduction. This work is likely to impact markedly upon the understanding of the receptor pharmacology of PAR(4) in normal physiology and disease. PMID:22411985

  9. Participation of Chromosome Segregation Protein ParAI of Vibrio cholerae in Chromosome Replication▿ †

    PubMed Central

    Kadoya, Ryosuke; Baek, Jong Hwan; Sarker, Arnab; Chattoraj, Dhruba K.

    2011-01-01

    Vibrio cholerae carries homologs of plasmid-borne parA and parB genes on both of its chromosomes. The par genes help to segregate many plasmids and chromosomes. Here we have studied the par genes of V. cholerae chromosome I. Earlier studies suggested that ParBI binds to the centromeric site parSI near the origin of replication (oriI), and parSI-ParBI complexes are placed at the cell poles by ParAI. Deletion of parAI and parSI caused the origin-proximal DNA to be less polar. Here we found that deletion of parBI also resulted in a less polar localization of oriI. However, unlike the deletion of parAI, the deletion of parBI increased the oriI number. Replication was normal when both parAI and parBI were deleted, suggesting that ParBI mediates its action through ParAI. Overexpression of ParAI in a parABI-deleted strain also increased the DNA content. The results are similar to those found for Bacillus subtilis, where ParA (Soj) stimulates replication and this activity is repressed by ParB (SpoOJ). As in B. subtilis, the stimulation of replication most likely involves the replication initiator DnaA. Our results indicate that control of chromosomal DNA replication is an additional function of chromosomal par genes conserved across the Gram-positive/Gram-negative divide. PMID:21257772

  10. Predicted PAR1 inhibitors from multiple computational methods

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Liu, Jinfeng; Zhu, Tong; Zhang, Lujia; He, Xiao; Zhang, John Z. H.

    2016-08-01

    Multiple computational approaches are employed in order to find potentially strong binders of PAR1 from the two molecular databases: the Specs database containing more than 200,000 commercially available molecules and the traditional Chinese medicine (TCM) database. By combining the use of popular docking scoring functions together with detailed molecular dynamics simulation and protein-ligand free energy calculations, a total of fourteen molecules are found to be potentially strong binders of PAR1. The atomic details in protein-ligand interactions of these molecules with PAR1 are analyzed to help understand the binding mechanism which should be very useful in design of new drugs.

  11. Hybrid chirped pulse amplification system

    DOEpatents

    Barty, Christopher P.; Jovanovic, Igor

    2005-03-29

    A hybrid chirped pulse amplification system wherein a short-pulse oscillator generates an oscillator pulse. The oscillator pulse is stretched to produce a stretched oscillator seed pulse. A pump laser generates a pump laser pulse. The stretched oscillator seed pulse and the pump laser pulse are directed into an optical parametric amplifier producing an optical parametric amplifier output amplified signal pulse and an optical parametric amplifier output unconverted pump pulse. The optical parametric amplifier output amplified signal pulse and the optical parametric amplifier output laser pulse are directed into a laser amplifier producing a laser amplifier output pulse. The laser amplifier output pulse is compressed to produce a recompressed hybrid chirped pulse amplification pulse.

  12. Stress pulse phenomena

    SciTech Connect

    McGlaun, M.

    1993-08-01

    This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

  13. Laser fusion pulse shape controller

    DOEpatents

    Siebert, Larry D.

    1977-01-01

    An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

  14. Ultrasonic thermometry using pulse techniques.

    NASA Technical Reports Server (NTRS)

    Lynnworth, L. C.; Carnevale, E. H.

    1972-01-01

    Ultrasonic pulse techniques have been developed which, when applied to inert gases, provide temperature measurements up to 8000 K. The response time can be less than 1 msec. This is a significant feature in studying shock-heated or combusting gases. Using a momentary contact coupling technique, temperature has been measured inside steel from 300 to 1500 K. Thin-wire sensors have been used above 2000 K in nuclear and industrial applications where conditions preclude the use of thermocouples, resistance devices, or optical pyrometers. At 2500 K, temperature sensitivity of 0.1% is obtained in Re wire sensors 5 cm long by timing five round trips with an electronic instrument that resolves the time interval between selected echoes to 0.1 microsec. Sensors have been operated at rotational speeds over 2000 rpm and in noisy environments. Temperature profiling of up to ten regions using only a single guided path or beam has also been accomplished.

  15. PULSE DURATION LENGTHENER

    DOEpatents

    Aiken, W.R.

    1958-02-01

    This patent pertains to pulse modifying apparatus and, more particularly, describes a device to provide a rise time and time base expander for signal pulses having a very short duration. The basic element of the device is a vacuum tube comprising a charged particie beam, grid control means, an accelerating electrode, a drift tube, and a collector electrode. As the short duration input pulse modulates the particle beam through the grid control means, the voltage between the drift tube and accelerating electrode is caused to vary, whereby the output signal from the collector is a pulse having longer rise time, expanded duration and proportionate characteristics of the original pulse. The invention is particuiarly useful where subsequent pulse circultry does not have the frequency bandwidth to handle the short duration pulse without distorting it.

  16. ELECTRICAL PULSE COUNTER APPARATUS

    DOEpatents

    Kaufman, W.M.; Jeeves, T.A.

    1962-09-01

    A progressive electrical pulse counter circuit rs designed for the counting of a chain of input pulses. The circuit employs a series of direct connected bistable counting stages simultaneously pulsed by each input pulse and a delay means connected between each of the stages. Each bistable stage has two d-c operative states, which stage, when in its initial state, prevents the next succeeding stage from changing its condition when the latter stage is pulsed. Since the delay circuits between the stages prevents the immediate decay of the d-c state of each stage when the stages are pulsed, only one stage will change its state for each input pulse, thereby providing progressive stage-by-stage counting. (AEC)

  17. Indication of Local Laser Pump Depletion via Transmitted Self-Guided Laser Light

    SciTech Connect

    Pak, A. E.; Marsh, K. A.; Ralph, J. E.; Lu, W.; Clayton, C. E.; Joshi, C.

    2009-01-22

    In recent experiments it has been shown that an ultra-intense, ultra-short laser pulse can be self-guided over tens of Rayleigh lengths in an underdense plasma where {tau}(FWHM of the laser pulse) is on the order of the plasma wavelength ({lambda}{sub p}). Using an imaging spectrograph, the frequency of the transmitted laser pulse was spatially and spectrally resolved at the exit of 3, 5, and 8 mm long plasmas. The mechanism of laser pump depletion was studied by observing the amount that the transmitted laser pulse's spectrum was red shifted in wavelength through the interaction with the self-guiding plasma wave.

  18. View from northeast to southwest of PAR site sentry station; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from northeast to southwest of PAR site sentry station; formerly the bachelor's enlisted men's quarter (BEQ) - Stanley R. Mickelsen Safeguard Complex, Sentry Station, North of Second Avenue & West of Electrical Switch Station No. 2, Nekoma, Cavalier County, ND

  19. View from southwest to northeast of PAR site fresh water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from southwest to northeast of PAR site fresh water pump house - Stanley R. Mickelsen Safeguard Complex, Fresh Water Pump House, In Limited Access Area, on Patrol Road next to Open Storage Reservoir No. 736, Nekoma, Cavalier County, ND

  20. PARS: Programs for Analysis and Resizing of Structures, user manual

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Prasad, B.; Tsach, U.

    1979-01-01

    PARS processors and their use, flutter analysis, sensitivity analysis for stresses, and resizing are presented. Design variable definition and interface with finite element model, static constraints and their derivatives, flutter derivatives, and optimization are discussed.

  1. Genome-wide identification of miRNA targets by PAR-CLIP

    PubMed Central

    Hafner, Markus; Lianoglou, Steve; Tuschl, Thomas; Betel, Doron

    2012-01-01

    MiRNAs are short (20-23 nt) RNAs that are loaded into proteins of the Argonaute (AGO) family and guide them to partially complementary target sites on mRNAs, resulting in mRNA destabilization and/or translational repression. It is estimated that about 60% of the mammalian genes are potentially regulated by miRNAs, and therefore methods for experimental miRNA target determination have become valuable tools for the characterization of posttranscriptional gene regulation. Here we present a step-by-step protocol and guidelines for the computational analysis for the large-scale identification of miRNA target sites in cultured cells by photoactivatable ribonucleoside enhanced crosslinking and immunoprecipitation (PAR-CLIP) of AGO proteins. PMID:22926237

  2. Par-4 secretion: stoichiometry of 3-arylquinoline binding to vimentin.

    PubMed

    Sviripa, Vitaliy M; Burikhanov, Ravshan; Obiero, Josiah M; Yuan, Yaxia; Nickell, Justin R; Dwoskin, Linda P; Zhan, Chang-Guo; Liu, Chunming; Tsodikov, Oleg V; Rangnekar, Vivek M; Watt, David S

    2016-01-01

    Advanced prostate tumors usually metastasize to the lung, bone, and other vital tissues and are resistant to conventional therapy. Prostate apoptosis response-4 protein (Par-4) is a tumor suppressor that causes apoptosis in therapy-resistant prostate cancer cells by binding specifically to a receptor, Glucose-regulated protein-78 (GRP78), found only on the surface of cancer cells. 3-Arylquinolines or "arylquins" induce normal cells to release Par-4 from the intermediate filament protein, vimentin and promote Par-4 secretion that targets cancer cells in a paracrine manner. A structure-activity study identified arylquins that promote Par-4 secretion, and an evaluation of arylquin binding to the hERG potassium ion channel using a [(3)H]-dofetilide binding assay permitted the identification of structural features that separated this undesired activity from the desired Par-4 secretory activity. A binding study that relied on the natural fluorescence of arylquins and that used the purified rod domain of vimentin (residues 99-411) suggested that the mechanism behind Par-4 release involved arylquin binding to multiple sites in the rod domain. PMID:26548370

  3. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    NASA Astrophysics Data System (ADS)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  4. PULSE RATE DIVIDER

    DOEpatents

    McDonald, H.C. Jr.

    1962-12-18

    A compact pulse-rate divider circuit affording low impedance output and high input pulse repetition rates is described. The circuit features a single secondary emission tube having a capacitor interposed between its dynode and its control grid. An output pulse is produced at the anode of the tube each time an incoming pulse at the control grid drives the tube above cutoff and the duration of each output pulse corresponds to the charging time of the capacitor. Pulses incoming during the time the grid bias established by the discharging capacitor is sufficiently negative that the pulses are unable to drive the tube above cutoff do not produce output pulses at the anode; these pulses are lost and a dividing action is thus produced by the circuit. The time constant of the discharge path may be vanied to vary in turn the division ratio of the circuit; the time constant of the charging circuit may be varied to vary the width of the output pulses. (AEC)

  5. PULSE HEIGHT ANALYZER

    DOEpatents

    Goldsworthy, W.W.

    1958-06-01

    A differential pulse-height discriminator circuit is described which is readily adaptable for operation in a single-channel pulse-height analyzer. The novel aspect of the circuit lies in the specific arrangement of differential pulse-height discriminator which includes two pulse-height discriminators having a comnnon input and an anticoincidence circuit having two interconnected vacuum tubes with a common cathode resistor. Pulses from the output of one discriminator circuit are delayed and coupled to the grid of one of the anticoincidence tubes by a resistor. The output pulses from the other discriminator circuit are coupled through a cathode follower circuit, which has a cathode resistor of such value as to provide a long time constant with the interelectrode capacitance of the tube, to lenthen the output pulses. The pulses are then fed to the grid of the other anticoincidence tube. With such connections of the circuits, only when the incoming pulse has a pesk value between the operating levels of the two discriminators does an output pulse occur from the anticoincidence circuit.

  6. PULSE AMPLITUDE ANALYZER

    DOEpatents

    Gray, G.W.; Jensen, A.S.

    1957-10-22

    A pulse-height analyzer system of improved design for sorting and counting a series of pulses, such as provided by a scintillation detector in nuclear radiation measurements, is described. The analyzer comprises a main transmission line, a cathode-ray tube for each section of the line with its deflection plates acting as the line capacitance; means to bias the respective cathode ray tubes so that the beam strikes a target only when a prearranged pulse amplitude is applied, with each tube progressively biased to respond to smaller amplitudes; pulse generating and counting means associated with each tube to respond when the beam is deflected; a control transmission line having the same time constant as the first line per section with pulse generating means for each tube for initiating a pulse on the second transmission line when a pulse triggers the tube of corresponding amplitude response, the former pulse acting to prevent successive tubes from responding to the pulse under test. This arrangement permits greater deflection sensitivity in the cathode ray tube and overcomes many of the disadvantages of prior art pulse-height analyzer circuits.

  7. Nanopore formation in neuroblastoma cells following ultrashort electric pulse exposure

    NASA Astrophysics Data System (ADS)

    Roth, Caleb C.; Payne, Jason A.; Wilmink, Gerald J.; Ibey, Bennett L.

    2011-03-01

    Ultrashort or nanosecond electrical pulses (USEP) cause repairable damage to the plasma membranes of cells through formation of nanopores. These nanopores are able to pass small ions such as sodium, calcium, and potassium, but remain impermeable to larger molecules like trypan blue and propidium iodide. What remains uncertain is whether generation of nanopores by ultrashort electrical pulses can inhibit action potentials in excitable cells. In this paper, we explored the sensitivity of excitable cells to USEP using Calcium Green AM 1 ester fluorescence to measure calcium uptake indicative of nanopore formation in the plasma membrane. We determined the threshold for nanopore formation in neuroblastoma cells for three pulse parameters (amplitude, pulse width, and pulse number). Measurement of such thresholds will guide future studies to determine if USEP can inhibit action potentials without causing irreversible membrane damage.

  8. Electromagnetically induced guiding of counterpropagating lasers in plasmas

    SciTech Connect

    Shvets, G.; Pukhov, A.

    1999-01-01

    The interaction of counterpropagating laser pulses in a plasma is considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order of the plasma period) laser pulse can also be nonlinearly focused by a long counterpropagating beam which extends over the entire guiding length. This phenomenon of electromagnetically induced guiding can be utilized in laser-driven plasma accelerators. {copyright} {ital 1999} {ital The American Physical Society}

  9. PULSE AMPLITUDE ANALYZER

    DOEpatents

    Greenblatt, M.H.

    1958-03-25

    This patent pertains to pulse amplitude analyzers for sorting and counting a serles of pulses, and specifically discloses an analyzer which ls simple in construction and presents the puise height distribution visually on an oscilloscope screen. According to the invention, the pulses are applied to the vertical deflection plates of an oscilloscope and trigger the horizontal sweep. Each pulse starts at the same point on the screen and has a maximum amplitude substantially along the same vertical line. A mask is placed over the screen except for a slot running along the line where the maximum amplitudes of the pulses appear. After the slot has been scanned by a photocell in combination with a slotted rotating disk, the photocell signal is displayed on an auxiliary oscilloscope as vertical deflection along a horizontal time base to portray the pulse amplitude distribution.

  10. Random pulse generator

    NASA Technical Reports Server (NTRS)

    Lindsey, R. S., Jr. (Inventor)

    1975-01-01

    An exemplary embodiment of the present invention provides a source of random width and random spaced rectangular voltage pulses whose mean or average frequency of operation is controllable within prescribed limits of about 10 hertz to 1 megahertz. A pair of thin-film metal resistors are used to provide a differential white noise voltage pulse source. Pulse shaping and amplification circuitry provide relatively short duration pulses of constant amplitude which are applied to anti-bounce logic circuitry to prevent ringing effects. The pulse outputs from the anti-bounce circuits are then used to control two one-shot multivibrators whose output comprises the random length and random spaced rectangular pulses. Means are provided for monitoring, calibrating and evaluating the relative randomness of the generator.

  11. PULSE AMPLITUDE ANALYSERS

    DOEpatents

    Lewis, I.A.D.

    1956-05-15

    This patent pentains to an electrical pulse amplitude analyzer, capable of accepting input pulses having a separation between adjacent pulses in the order of one microsecond while providing a large number of channels of classification. In its broad aspect the described pulse amplitude analyzer utilizes a storage cathode ray tube und control circuitry whereby the amplitude of the analyzed pulses controls both the intensity and vertical defiection of the beam to charge particular spots in horizontal sectors of the tube face as the beam is moved horizontally across the tube face. As soon as the beam has swept the length of the tube the information stored therein is read out by scanning individually each horizontal sector corresponding to a certain range of pulse amplitudes and applying the output signal from each scan to separate indicating means.

  12. The Role of Pulses in the Dietary Management of Diabetes.

    PubMed

    Ramdath, Dan; Renwick, Simone; Duncan, Alison M

    2016-08-01

    Pulses are highly nutritious foods that are included as part of Canada's Food Guide to promote healthful eating, and they have established health benefits that can contribute to the dietary management of diabetes. A review of studies that have examined the effects of pulse consumption on health outcomes, integral to the management of diabetes, provides credible evidence for improvements in glycemic control, reduction of blood lipids and regulation of body weight. Results from acute feeding trials suggest that postprandial blood glucose response is significantly attenuated by a single pulse serving of between three-quarters and 1 cup. At lower doses, pulses attenuate postprandial blood glucose response more than similar amounts of starchy foods. Long-term pulse consumption of 5 cups per week appears to result consistently in improvements in glycemic control. There is high-quality evidence that supports a role for pulse consumption in the reduction of risk for cardiovascular disease; this provides a sound rationale for the regular incorporation of pulses at about two-thirds of a cup daily in the management of hyperlipidemia in persons with type 2 diabetes. Pulse consumption can contribute to improving satiety, reducing food intake and regulating body weight, which can reduce obesity risk and, in turn, improve diabetes management. Collectively, available evidence provides very good support for a role of regular pulse consumption in the prevention and management of diabetes. PMID:27497151

  13. Laser Guiding at Relativistic Intensities and Wakefield ParticleAcceleration in Plasma Channels

    SciTech Connect

    Geddes, C.G.R.; Toth, Cs.; van Tilborg, J.; Esarey, E.; Schroeder, C.B.; Bruhwiler, D.; Nieter, C.; Cary, J.; Leemans, W.P.

    2005-05-01

    High quality electron beams with hundreds of picoCoulombs ofcharge inpercent energy spread above 80 MeV were produced for the firsttime in high gradient laser wakefield accelerators by guiding the drivelaser pulse.

  14. PULSED INDICATOR CIRCUIT

    DOEpatents

    Linlor, W.I.; Kerns, Q.A.

    1960-11-15

    A system is given for detecting incremental changes in a transducer impedance terminating a transmission line. Principal novelty resides in the transducer impedance terminating the line in a mismatch and a pulse generator being provided to apply discrete pulses to the input end of the line. The amplitudes of the pulses reflected to the input end of the line from the mismatched transducer impedance are then observed as a very accurate measure of the instantaneous value of the latter.

  15. PulseSoar

    SciTech Connect

    Carter, P.; Peglow, S.

    1992-07-21

    This paper is an introduction to the PulseSoar concept. PulseSoar is a hypervelocity airplane that uses existing airport facilities and current technologies to fly at the very edge of space. It will be shown that PulseSoar can fly between any two points on the globe in less than two hours with fuel efficiency exceeding current state of the art commercial airliners. In addition, it will be shown that PulseSoar avoids environmental issues concerning the ozone layer and sonic booms because of its unique flight profile. All of this can be achieved with current technology. PulseSoar does not require the development of enabling technology. It is a concept which can be demonstrated today. The importance of this idea goes beyond the technical significance`s of PulseSoar in terms of feasibility and performance. PulseSoar could provide a crucial economic advantage to America`s largest export market: commercial aircraft. PulseSoar is a breakthrough concept for addressing the emerging markets of long range and high speed aircraft. Application of PulseSoar to commercial transport could provide the US Aerospace industry a substantial lead in offering high speed/long range aircraft to the world`s airlines. The rapid emergence of a US developed high speed aircraft could also be important to our competitiveness in the Pacific Rim and South American economies. A quick and inexpensive demonstration vehicle is proposed to bang the concept to reality within two years. This discussion will address all the major technical subjects encompassed by PulseSoar and identifies several near-term, and low risk, applications which may be further explored with the initial demonstration vehicle. What is PulseSoar? PulseSoar could enable high speed, high altitude and long range flight without many of the difficulties encountered by traditional hypersonic vehicles.

  16. High voltage pulse conditioning

    DOEpatents

    Springfield, Ray M.; Wheat, Jr., Robert M.

    1990-01-01

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  17. Plasma channel guided laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Geddes, Cameron Guy Robinson

    2005-11-01

    High quality electron beams (several 109 electrons above 80 MeV energy with percent energy spread and low divergence) have been produced for the first time in a compact, high gradient, all-optical laser accelerator by extending the interaction distance using a pre-formed plasma density channel to guide the drive laser pulse. Laser-driven accelerators, in which particles are accelerated by the electric field of a plasma wave (wake) driven by the radiation pressure of an intense laser, have over the past decade demonstrated accelerating fields thousands of times greater than those achievable in conventional radio-frequency accelerators. This has spurred interest in them as compact next-generation sources of energetic electrons and radiation. To date, however, acceleration distances have been severely limited by the lack of a controllable method for extending the propagation distance of the focused laser pulse. The ensuing short acceleration distance resulted in low-energy beams with 100 percent electron energy spread, which has limited potential applications. Optical guiding of relativistically intense (>1018 W/cm 2) laser pulses over distances greater than 10 diffraction lengths is demonstrated herein using plasma channels, which have a density minimum on the axis of propagation, formed by hydrodynamic shock. Laser modes with peak powers of up to 4 TW---twice the self-guiding threshold---were guided without aberration by tuning the plasma density profile. The transmitted optical spectrum showed that the pulse remained in the channel over the entire length, and no accelerated electrons were observed at these powers. Simulations indicated that a large plasma wave was driven by the 4 TW pulse, indicating a possible dark current free structure for a laser wakefield accelerator using controlled injection. The presence of a large plasma wave was verified by increasing laser power and observing electron acceleration. At a guided drive pulse power of 9 TW (500 mJ in 50 fs

  18. Pulse Tube Refrigerator

    NASA Astrophysics Data System (ADS)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  19. Femtosecond polarization pulse shaping.

    PubMed

    Brixner, T; Gerber, G

    2001-04-15

    We report computer-controlled femtosecond polarization pulse shaping where intensity, momentary frequency, and light polarization are varied as functions of time. For the first time to our knowledge, a pulse shaper is used to modulate the degree of ellipticity as well as the orientation of the elliptical principal axes within a single laser pulse by use of a 256-pixel two-layer liquid-crystal display inside a zero-dispersion compressor. Interferometric stability of the setup is not required. Complete pulse characterization is achieved by dual-channel spectral interferometry. This technology has a large range of applications, especially in the field of quantum control. PMID:18040384

  20. High Power Disk Loaded Guide Load

    SciTech Connect

    Farkas, Z.D.; /SLAC

    2006-02-22

    A method to design a matching section from a smooth guide to a disk-loaded guide, using a variation of broadband matching, [1, 2] is described. Using this method, we show how to design high power loads. The load consists of a disk-loaded coaxial guide operating in the TE{sub 01}-mode. We use this mode because it has no electric field terminating on a conductor, has no axial currents, and has no current at the cylinder-disk interface. A high power load design that has -35 dB reflection and a 200 MHz, -20 dB bandwidth, is presented. It is expected that it will carry the 600 MW output peak power of the pulse compression network. We use coaxial geometry and stainless steel material to increase the attenuation per cell.

  1. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned.

  2. Pars Planitis: Epidemiology, Clinical Characteristics, Management and Visual Prognosis

    PubMed Central

    Ozdal, Pinar Cakar; Berker, Nilufer; Tugal-Tutkun, Ilknur

    2015-01-01

    Pars planitis is an idiopathic chronic intermediate uveitis which predominantly affects children and adolescents, and accounts for 5-26.7% of pediatric uveitis. Although an autoimmune process with a genetic predisposition has been suggested, its etiology still remains unknown. The most common presenting symptoms are floaters and blurred vision. Diffuse vitreous cells, haze, snowballs and snowbanks are typical findings of pars planitis. Peripheral retinal vasculitis, optic disc edema and anterior segment inflammation are other well-known findings. Although pars planitis is known to be a benign form of uveitis in most cases, it may become a potentially blinding disease due to complications including cataract, cystoid macular edema, vitreous opacities and optic disc edema. Cystoid macular edema is the most common cause of visual morbidity. Band keratopathy, epiretinal membrane formation, vitreous condensation, neovascularizations, vitreous hemorrhage, retinal detachment, cyclitic membranes, glaucoma and amblyopia may develop as a consequence of the chronic course of the disease. Exclusion of infectious and non-infectious causes which may present with intermediate uveitis is of utmost importance before starting treatment. Treatment of pars planitis has been a controversial issue. There is no consensus specifically for treatment of cases with minimal inflammation and relatively good visual acuity. However, current experience shows that pars planitis may cause severe inflammation and needs an aggressive treatment. A stepladder approach including corticosteroids, immunosupressive agents, anti-tumor necrosis factor-alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis. Adequate control of inflammation and prompt detection of associated complications are crucial in order to improve the overall prognosis of the disease. PMID:27051493

  3. Combined pars plana vitrectomy-scleral buckle versus pars plana vitrectomy for proliferative vitreoretinopathy.

    PubMed

    Lai, Frank H P; Lo, Ernie C F; Chan, Vesta C K; Brelen, Mårten; Lo, Wai Ling; Young, Alvin L

    2016-04-01

    The purpose of the study is to evaluate the surgical outcomes of combined pars plana vitrectomy-scleral buckle (PPV-SB) versus pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy (PVR). One thousand one hundred and seventy four patients with rhegmatogenous retinal detachment surgery between January 2002 and December 2013 were retrospectively reviewed. Patients with grade C PVR treated with either combined PPV-SB or PPV alone were included in the study. Study outcomes included single surgery anatomic success rate and postoperative visual outcome at 12 months postoperatively. Seventy-seven patients with grade C PVR were identified for analysis. At the end of 12-month follow-up, 80.5 % eyes (33/41) in the PPV-SB group and 58.3 % eyes (21/36) in the PPV group achieved single surgery anatomical success. In a multiple logistic regression model, none of the baseline variables (age, gender, macula status, grade of PVR, extent of detachment, presence of vitreous hemorrhage, lens status, status of high myopia) nor types of retinal detachment surgery (use of scleral buckle, barrier endolaser, 360 degree endolaser, cryopexy, retinectomy, tamponade agent, phacoemulsification) had significant effect on single surgery anatomical success. The post-treatment mean logMAR visual acuity of the PPV-SB group was 1.58 ± 0.58 and the PPV group was 1.57 ± 0.61. There was no significant difference in the postoperative visual acuity between the two groups (P = 0.849). For patients with grade C PVR, PPV-SB did not demonstrate a superiority over PPV alone in achieving single surgery anatomical success. PMID:26260357

  4. Opportunities in pulse combustion

    NASA Astrophysics Data System (ADS)

    Brenchley, D. L.; Bomelburg, H. J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  5. Ionization and pulse lethargy effects in inverse Cherenkov accelerators

    SciTech Connect

    Sprangle, P.; Hubbard, R.F.,; Hafizi, B.,

    1997-05-01

    Ionization processes limit the accelerating gradient and place an upper limit on the pulse duration of the electromagnetic driver in the inverse Cherenkov accelerator (ICA). Group velocity slippage, i.e., pulse lethargy, on the other hand, imposes a lower limit on the pulse duration. These limits are obtained for two ICA configurations in which the electromagnetic driver (e.g., laser or millimeter wave source) is propagated in a waveguide that is (i) lined with a dielectric material or (ii) filled with a neutral gas. In either configuration the electromagnetic driving field is guided and has an axial electric field with phase velocity equal to the speed of light in vacuum, c. The intensity of the driver in the ICA, and therefore the acceleration gradient, is limited by tunneling and collisional ionization effects. Partial ionization of the dielectric liner or gas can lead to significant modification of the dispersive properties of the waveguide, altering the phase velocity of the accelerating field and causing particle slippage, thus disrupting the acceleration process. An additional limitation on the pulse duration is imposed since the group velocity of the driving pulse is less than c and the pulse slips behind the accelerated electrons. Hence for sufficiently short pulses the electrons outrun the pulse, terminating the acceleration. Limitations on the driver pulse duration and accelerating gradient, due to ionization and pulse lethargy, are estimated for the two ICA configurations. Maximum accelerating gradients and pulse durations are presented for a 10 {mu}m, 1 mm, and 1 cm wavelength electromagnetic driver. The combination of ionization and pulse lethargy effects impose severe limitations on the maximum energy gain in inverse Cherenkov accelerators. {copyright} {ital 1997} {ital The American Physical Society}

  6. A Guide to Health Occupations. Teacher's Guide.

    ERIC Educational Resources Information Center

    Cheu, Janey M. Y.; And Others

    This guide is intended to assist teachers in using a companion health career reference as a class text for introducing students to the health field. The first two sections describe the purposes and organization of the companion guide. Discussed next are ways of helping students explore health career opportunities and options and come to understand…

  7. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  8. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  9. Pulse pile-up effects

    SciTech Connect

    Tenney, F.H.

    1983-05-01

    The energy spectrum containing the effects of all orders of pulse pileup is predicted for an idealized x-ray pulse-height-analysis system measuring randomly occurring events. Two simplifying assumptions used are first a fixed pulse resolution time and second that the measured energy of piled-up pulses is the algebraic sum of the energy associated with each pulse.

  10. PULSE AMPLITUDE DISTRIBUTION RECORDER

    DOEpatents

    Cowper, G.

    1958-08-12

    A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

  11. PULSE HEIGHT ANALYZER

    DOEpatents

    Johnstone, C.W.

    1958-01-21

    An anticoincidence device is described for a pair of adjacent channels of a multi-channel pulse height analyzer for preventing the lower channel from generating a count pulse in response to an input pulse when the input pulse has sufficient magnitude to reach the upper level channel. The anticoincidence circuit comprises a window amplifier, upper and lower level discriminators, and a biased-off amplifier. The output of the window amplifier is coupled to the inputs of the discriminators, the output of the upper level discriminator is connected to the resistance end of a series R-C network, the output of the lower level discriminator is coupled to the capacitance end of the R-C network, and the grid of the biased-off amplifier is coupled to the junction of the R-C network. In operation each discriminator produces a negative pulse output when the input pulse traverses its voltage setting. As a result of the connections to the R-C network, a trigger pulse will be sent to the biased-off amplifier when the incoming pulse level is sufficient to trigger only the lower level discriminator.

  12. Sources of pulsed radiation

    SciTech Connect

    Sauer, M.C. Jr.

    1981-01-01

    Characteristics of various sources of pulsed radiation are examined from the viewpoint of their importance to the radiation chemist, and some examples of uses of such sources are mentioned. A summary is given of the application of methods of physical dosimetry to pulsed sources, and the calibration of convenient chemical dosimeters by physical dosimetry is outlined. 7 figures, 1 table.

  13. Extrusion cooking: Legume pulses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion is used commercially to produce high value breakfast and snack foods based on cereals such as wheat or corn. However, this processing method is not being commercially used for legume pulses seeds due to the perception that they do not expand well in extrusion. Extrusion cooking of pulses (...

  14. Bipolar pulse generator for intense pulsed ion beam accelerator

    SciTech Connect

    Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K.

    2007-01-15

    A new type of pulsed ion beam accelerator named ''bipolar pulse accelerator'' (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time.

  15. Bipolar pulse generator for intense pulsed ion beam accelerator.

    PubMed

    Ito, H; Igawa, K; Kitamura, I; Masugata, K

    2007-01-01

    A new type of pulsed ion beam accelerator named "bipolar pulse accelerator" (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time. PMID:17503918

  16. Composite Pulse Tube

    NASA Technical Reports Server (NTRS)

    Martin, Jerry L.; Cloyd, Jason H.

    2007-01-01

    A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high

  17. ELECTRIC PULSE GENERATOR

    DOEpatents

    Buntenbach, R.W.

    1959-06-01

    S>An electro-optical apparatus is described which produces electric pulses in programmed sequences at times and durations controlled with great accuracy. An oscilloscope CRT is supplied with signals to produce a luminous spot moving in a circle. An opaque mask with slots of variable width transmits light from the spot to a photoelectric transducer. For shorter pulse decay times a CRT screen which emits UV can be used with a UVtransmitting filter and a UV- sensitive photoelectric cell. Pulses are varied by changing masks or by using masks with variable slots. This device may be used in multiple arrangements to produce other pulse aT rangements, or it can be used to trigger an electronic pulse generator. (T.R.H.)

  18. Pulsed hall thruster system

    NASA Technical Reports Server (NTRS)

    Hruby, Vladimir J. (Inventor); Pote, Bruce M. (Inventor); Gamero-Castano, Manuel (Inventor)

    2004-01-01

    A pulsed Hall thruster system includes a Hall thruster having an electron source, a magnetic circuit, and a discharge chamber; a power processing unit for firing the Hall thruster to generate a discharge; a propellant storage and delivery system for providing propellant to the discharge chamber and a control unit for defining a pulse duration .tau.<0.1d.sup.3.rho./m, where d is the characteristic size of the thruster, .rho. is the propellant density at standard conditions, and m is the propellant mass flow rate for operating either the power processing unit to provide to the Hall thruster a power pulse of a pre-selected duration, .tau., or operating the propellant storage and delivery system to provide a propellant flow pulse of duration, .tau., or providing both as pulses, synchronized to arrive coincidentally at the discharge chamber to enable the Hall thruster to produce a discreet output impulse.

  19. Guide to Understanding Lymphedema

    MedlinePlus

    ... Diet, Nutrition and Exercise Expressive Writing Guided Imagery Hypnosis Massage Therapy Mindfulness-Based Stress Reduction Yoga and ... Diet, Nutrition and Exercise Expressive Writing Guided Imagery Hypnosis Massage Therapy Mindfulness-Based Stress Reduction Yoga and ...

  20. Localized wave pulse experiments

    SciTech Connect

    Chambers, D L; Henderson, T L; Krueger, K L; Lewis, D K; Zilkowski, R N

    1999-06-01

    The Localized Wave project of the Strategic System Support Program has recently finished an experiment in cooperation with the Advanced SONAR group of the Applied Research Laboratory of the University of Texas at Austin. The purpose of the experiment was three-fold. They wanted to see if (1) the LW pulse could propagate over significant distances, to see if (2) a new type of array and drive system specifically designed for the pulse would increase efficiency over single frequency tone bursts, and to see if (3) the complexity of our 24 channel drivers resulted in better efficiency than a single equivalent pulse driving a piston. In the experiment, several LW pulses were launched from the Lake Travis facility and propagated over distances of either 100 feet or 600 feet, through a thermocline for the 600 foot measurements. The results show conclusively that the Localized Wave will propagate past the near field distance. The LW pulses resulted in extremely broad frequency band width pulses with narrow spatial beam patterns and unmeasurable side lobes. Their array gain was better than most tone bursts and further, were better than their equivalent piston pulses. This marks the first test of several Low Diffraction beams against their equivalent piston pulses, as well as the first propagation of LW pulses over appreciable distances. The LW pulse is now proven a useful tool in open water, rather than a laboratory curiosity. The experimental system and array were built by ARL, and the experiments were conducted by ARL staff on their standard test range. The 600 feet measurements were made at the farthest extent of that range.

  1. PAR-1 phosphorylates Mind bomb to promote vertebrate neurogenesis

    PubMed Central

    Ossipova, Olga; Ezan, Jerome; Sokol, Sergei Y.

    2010-01-01

    Summary Generation of neurons in the vertebrate central nervous system requires complex transcriptional regulatory network and signaling processes in polarized neuroepithelial progenitor cells. Here we demonstrate that neurogenesis in the Xenopus neural plate in vivo and mammalian neural progenitors in vitro involves intrinsic antagonistic activities of the polarity proteins PAR-1 and aPKC. Furthermore, we show that Mind bomb (Mib), a ubiquitin ligase that promotes Notch ligand trafficking and activity, is a crucial molecular substrate for PAR-1. The phosphorylation of Mib by PAR-1 results in Mib degradation, repression of Notch signaling and stimulation of neuronal differentiation. These observations suggest a conserved mechanism for neuronal fate determination that might operate during asymmetric divisions of polarized neural progenitor cells. PMID:19686683

  2. Managerial Accounting. Study Guide.

    ERIC Educational Resources Information Center

    Plachta, Leonard E.

    This self-instructional study guide is part of the materials for a college-level programmed course in managerial accounting. The study guide is intended for use by students in conjuction with a separate textbook, Horngren's "Accounting for Management Control: An Introduction," and a workbook, Curry's "Student Guide to Accounting for Management…

  3. SMIP Chemistry Curriculum Guides.

    ERIC Educational Resources Information Center

    Wilkes Coll., Wilkes-Barre, PA.

    Included are most guides for a one-year course in senior high school chemistry. The guides may be interchanged at the teacher's discretion, following any text sequence or course outline. Each guide consists of six sections: (1) an approach, which briefly discusses the unit in terms of background material, pitfalls to be avoided, and suggested…

  4. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    Conard, David; Lawson, Chester A.

    This Teacher's Guide is designed for use with the Science Curriculum Improvement Study's (SCIS) unit Population. Populations is the third of a six-unit sequence of SCIS's Life Science Program for grades K-6. The Populations guide consists of activity outlines along with suggestions for guiding children's observation and manipulations of living…

  5. ESL VI Curriculum Guide.

    ERIC Educational Resources Information Center

    Flander, Leonard

    This curriculum guide for English as a Second Language (ESL) Level VI is the sixth of six in a Guam Community College ESL project series. The other five guides, a companion teacher's guide and pre- and post-tests are available separately (see note). The entire project centers around the Peabody Kits P, Level P, Level 1, Level 2, Level 3, and the…

  6. [Tennessee Kindergarten Curriculum Guides.

    ERIC Educational Resources Information Center

    Tennessee State Dept. of Education, Nashville.

    Provided are Tennessee's state kindergarten curriculum guides in the 6 areas of health, social studies, language arts, science, physical education, and mathematics. The health curriculum guide centers on developing and maintaining good health. The social studies guide aids children in understanding self as an individual and in relation to other…

  7. ESL V Curriculum Guide.

    ERIC Educational Resources Information Center

    Flander, Leonard

    This curriculum guide for English as a Second Language (ESL) Level V is the fifth of six in the Guam Community College ESL project series. The other five guides, a companion teacher's guide, and pre- and post-tests are available separately (see note). The entire project centers around the Peabody Kits P, Level P, Level 1, Level 2, Level 3, and the…

  8. Spatiotemporal optical pulse transformation by a resonant diffraction grating

    SciTech Connect

    Golovastikov, N. V.; Bykov, D. A. Doskolovich, L. L. Soifer, V. A.

    2015-11-15

    The diffraction of a spatiotemporal optical pulse by a resonant diffraction grating is considered. The pulse diffraction is described in terms of the signal (the spatiotemporal incident pulse envelope) passage through a linear system. An analytic approximation in the form of a rational function of two variables corresponding to the angular and spatial frequencies has been obtained for the transfer function of the system. A hyperbolic partial differential equation describing the general form of the incident pulse envelope transformation upon diffraction by a resonant diffraction grating has been derived from the transfer function. A solution of this equation has been obtained for the case of normal incidence of a pulse with a central frequency lying near the guided-mode resonance of a diffraction structure. The presented results of numerical simulations of pulse diffraction by a resonant grating show profound changes in the pulse envelope shape that closely correspond to the proposed theoretical description. The results of the paper can be applied in creating new devices for optical pulse shape transformation, in optical information processing problems, and analog optical computations.

  9. Bacterial actin: architecture of the ParMRC plasmid DNA partitioning complex.

    PubMed

    Salje, Jeanne; Löwe, Jan

    2008-08-20

    The R1 plasmid employs ATP-driven polymerisation of the actin-like protein ParM to move newly replicated DNA to opposite poles of a bacterial cell. This process is essential for ensuring accurate segregation of the low-copy number plasmid and is the best characterised example of DNA partitioning in prokaryotes. In vivo, ParM only forms long filaments when capped at both ends by attachment to a centromere-like region parC, through a small DNA-binding protein ParR. Here, we present biochemical and electron microscopy data leading to a model for the mechanism by which ParR-parC complexes bind and stabilise elongating ParM filaments. We propose that the open ring formed by oligomeric ParR dimers with parC DNA wrapped around acts as a rigid clamp, which holds the end of elongating ParM filaments while allowing entry of new ATP-bound monomers. We propose a processive mechanism by which cycles of ATP hydrolysis in polymerising ParM drives movement of ParR-bound parC DNA. Importantly, our model predicts that each pair of plasmids will be driven apart in the cell by just a single double helical ParM filament. PMID:18650930

  10. Observations of Radio Giant Pulses with GAVRT

    NASA Astrophysics Data System (ADS)

    Jones, Glenn

    2011-08-01

    Radio giant pulses provide a unique opportunity to study the pulsar radio emission mechanism in exquisite detail. Previous studies have revealed a wide range of properties and phenomena, including extraordinarily high brightness temperatures, sub-nanosecond emission features, and banded dynamic spectra. New measurements of giant pulse characteristics can help guide and test theoretical emission models. To this end, an extensive observation campaign has begun which will provide more than 500 hours on the Crab with a 34-meter antenna located in California, USA. The observations are being done as part of an educational outreach program called the Goldstone-Apple Valley Radio Telescope (GAVRT). This antenna has a novel wide bandwidth receiver which provides up to 8 GHz of instantaneous bandwidth in the range of 2.5 to 14 GHz. These observations will provide detailed information about the variability, amplitude distribution, and detailed frequency structure of radio giant pulses. In addition, a database of pulses from these observations and others of the Crab pulsar is being created which will simplify multiwavelength correlation analysis.

  11. La projection par plasma : une revue

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Grimaud, A.; Vardelle, A.; Vardelle, M.

    are presented in the fields of aeronautics and mechanics. La qualité d'un dépôt projete par plasma dépend de nombreux paramètres que l'on commence à mieux appréhender du fait des progrès de la modélisation et de la métrologie tant des écoulements plasmas que des transferts plasma-particules ou que des conditions d'écrasement et de refroidissement des particules lors de leur impact sur le substrat ou les couches déjà déposées. Les techniques de mesure utilisdes et leurs limitations sont d'abord rappelées tant pour les jets de plasma que pour les particules en vol et l'importance des différents phénomènes intervenant dans les transferts plasma-particules est soulignée : gradients de température et de concentration d'espèces chimiques très élevés autour des particules, effets de propagation de la chaleur, notamment pour les particules céramiques, effet d'évaporation, effet de raréfaction sensible dès la pression atmosphérique. Les problèmes de distribution de taille et de vitesse d'injection des particules sont également abordés car ils conditionnent les distributions de trajectoires et donc le traitement des particules dans le jet de plasma. La génération du plasma montre d'une part 1'influence considérable de l'injection du gaz, de sa nature, du dessin de la chambre d'arc et de la tuyère ainsi que du pompage de l'air ambiant sur la longueur des jets de plasma d'arc et d'autre part les problèmes d'injection pour éviter le couplage avec la décharge dans les jets de plasmas R.E Tout ceci est illustré avec des exemples de dépôt d'alumine, de zircone, de cermet carbure et de nickel. L'écrasement des particules est ensuite abordé avec les problèmes de réactions chimiques, de trempe ultra-rapide et donc de structure cristalline des dépôts, d'adhdsion mais aussi de containtes résiduelles et de leur contrôle via les gradients de température dans les dépôts pendant le tir. Enfin quelques applications actuelles sont pr

  12. Tesla coil discharges guided by femtosecond laser filaments in air

    NASA Astrophysics Data System (ADS)

    Brelet, Yohann; Houard, Aurélien; Arantchouk, Leonid; Forestier, Benjamin; Liu, Yi; Prade, Bernard; Carbonnel, Jérôme; André, Yves-Bernard; Mysyrowicz, André

    2012-04-01

    A Tesla coil generator was designed to produce high voltage pulses oscillating at 100 kHz synchronisable with a nanosecond temporal jitter. Using this compact high voltage generator, we demonstrate reproducible meter long discharges in air at a repetition rate of 1 Hz. Triggering and guiding of the discharges are performed in air by femtosecond laser filaments.

  13. Dynamic pulse difference circuit

    DOEpatents

    Erickson, Gerald L.

    1978-01-01

    A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter.

  14. Pulsed atomic soliton laser

    SciTech Connect

    Carr, L.D.; Brand, J.

    2004-09-01

    It is shown that simultaneously changing the scattering length of an elongated, harmonically trapped Bose-Einstein condensate from positive to negative and inverting the axial portion of the trap, so that it becomes expulsive, results in a train of self-coherent solitonic pulses. Each pulse is itself a nondispersive attractive Bose-Einstein condensate that rapidly self-cools. The axial trap functions as a waveguide. The solitons can be made robustly stable with the right choice of trap geometry, number of atoms, and interaction strength. Theoretical and numerical evidence suggests that such a pulsed atomic soliton laser can be made in present experiments.

  15. SHORT PULSE STRETCHER

    DOEpatents

    Branum, D.R.; Cummins, W.F.

    1962-12-01

    >A short pulse stretching circuit capable of stretching a short puise to enable it to be displayed on a relatively slow sweeping oscilloscope is described. Moreover, the duration of the pulse is increased by charging a capacitor through a diode and thereafter discharging the capacitor at such time as is desired. In the circuit the trigger pulse alone passes through a delay line, whereas the main signal passes through the diode only, and results in over-all circuit losses which are proportional to the low losses of the diode only. (AEC)

  16. Controlling Plasma Channels through Ultrashort Laser Pulse Filamentation

    NASA Astrophysics Data System (ADS)

    Ionin, Andrey; Seleznev, Leonid; Sunchugasheva, Elena

    2013-09-01

    A review of studies fulfilled at the Lebedev Institute in collaboration with the Moscow State University and Institute of Atmospheric Optics in Tomsk on influence of various characteristics of ultrashort laser pulse on plasma channels formed under its filamentation is presented. Filamentation of high-power laser pulses with wavefront controlled by a deformable mirror, with cross-sections spatially formed by various diaphragms and with different wavelengths was experimentally and numerically studied. An application of plasma channels formed due to filamentation of ultrashort laser pulse including a train of such pulses for triggering and guiding long electric discharges is discussed. The research was supported by RFBR Grants 11-02-12061-ofi-m and 11-02-01100, and EOARD Grant 097007 through ISTC Project 4073 P

  17. Experimental studies of laser guiding in plasma channels

    SciTech Connect

    Volfbeyn, P.; Leemans, W.P.

    1998-07-01

    The authors present results of experimental investigations of laser guiding in plasma channels. A new technique for plasma channel creation, the Ignitor-Heater scheme is proposed and experimentally tested in hydrogen and nitrogen. It makes use of two laser pulses. The Ignitor, an ultrashort (< 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used subsequently to heat the existing spark via inverse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows, creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. The channel density was diagnosed with time resolved longitudinal interferometry. From these measurements the plasma temperature was inferred. The guiding properties of the channels were tested by injecting a > 5 {times} 10{sup 17} W/cm{sup 2}, 75 fs laser pulse.

  18. Generation of intense, carrier-envelope phase-locked few-cycle laser pulses through filamentation

    NASA Astrophysics Data System (ADS)

    Hauri, C. P.; Kornelis, W.; Helbing, F. W.; Heinrich, A.; Couairon, A.; Mysyrowicz, A.; Biegert, J.; Keller, U.

    2004-10-01

    Intense, well-controlled light pulses with only a few optical cycles start to play a crucial role in many fields of physics, such as attosecond science. We present an extremely simple and robust technique to generate such carrier-envelope offset (CEO) phase locked few-cycle pulses, relying on self-guiding of intense 43-fs, 0.84 mJ optical pulses during propagation in a transparent noble gas. We have demonstrated 5.7-fs, 0.38 mJ pulses with an excellent spatial beam profile and discuss the potential for much shorter pulses. Numerical simulations confirm that filamentation is the mechanism responsible for pulse shortening. The method is widely applicable and much less sensitive to experimental conditions such as beam alignment, input pulse duration or gas pressure as compared to gas-filled hollow fibers.

  19. Pulse Coil Tester

    NASA Technical Reports Server (NTRS)

    Simon, Richard A.

    1988-01-01

    Set of relays tested easily and repeatedly. Pulse coil tester causes coil under test to generate transient voltage; waveform indicates condition of coil. Tester accommodates assembly of up to four coils at a time.

  20. HIGH POWER PULSED OSCILLATOR

    DOEpatents

    Singer, S.; Neher, L.K.

    1957-09-24

    A high powered, radio frequency pulse oscillator is described for generating trains of oscillations at the instant an input direct voltage is impressed, or immediately upon application of a light pulse. In one embodiment, the pulse oscillator comprises a photo-multiplier tube with the cathode connected to the first dynode by means of a resistor, and adjacent dynodes are connected to each other through adjustable resistors. The ohmage of the resistors progressively increases from a very low value for resistors adjacent the cathode to a high value adjacent the plate, the last dynode. Oscillation occurs with this circuit when a high negative voltage pulse is applied to the cathode and the photo cathode is bombarded. Another embodiment adds capacitors at the resistor connection points of the above circuit to increase the duration of the oscillator train.

  1. Pulsed-neutron monochromator

    DOEpatents

    Mook, H.A. Jr.

    1984-01-01

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  2. Pulsed-neutron monochromator

    DOEpatents

    Mook, Jr., Herbert A.

    1985-01-01

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  3. PH motifs in PAR1&2 endow breast cancer growth

    PubMed Central

    Kancharla, A.; Maoz, M.; Jaber, M.; Agranovich, D.; Peretz, T.; Grisaru-Granovsky, S.; Uziely, B.; Bar-Shavit, R.

    2015-01-01

    Although emerging roles of protease-activated receptor1&2 (PAR1&2) in cancer are recognized, their underlying signalling events are poorly understood. Here we show signal-binding motifs in PAR1&2 that are critical for breast cancer growth. This occurs via the association of the pleckstrin homology (PH) domain with Akt/PKB as a key signalling event of PARs. Other PH-domain signal-proteins such as Etk/Bmx and Vav3 also associate with PAR1 and PAR2 through their PH domains. PAR1 and PAR2 bind with priority to Etk/Bmx. A point mutation in PAR2, H349A, but not in R352A, abrogates PH-protein association and is sufficient to markedly reduce PAR2-instigated breast tumour growth in vivo and placental extravillous trophoblast (EVT) invasion in vitro. Similarly, the PAR1 mutant hPar1-7A, which is unable to bind the PH domain, reduces mammary tumours and EVT invasion, endowing these motifs with physiological significance and underscoring the importance of these previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological and physiological invasion processes. PMID:26600192

  4. PH motifs in PAR1&2 endow breast cancer growth.

    PubMed

    Kancharla, A; Maoz, M; Jaber, M; Agranovich, D; Peretz, T; Grisaru-Granovsky, S; Uziely, B; Bar-Shavit, R

    2015-01-01

    Although emerging roles of protease-activated receptor1&2 (PAR1&2) in cancer are recognized, their underlying signalling events are poorly understood. Here we show signal-binding motifs in PAR1&2 that are critical for breast cancer growth. This occurs via the association of the pleckstrin homology (PH) domain with Akt/PKB as a key signalling event of PARs. Other PH-domain signal-proteins such as Etk/Bmx and Vav3 also associate with PAR1 and PAR2 through their PH domains. PAR1 and PAR2 bind with priority to Etk/Bmx. A point mutation in PAR2, H349A, but not in R352A, abrogates PH-protein association and is sufficient to markedly reduce PAR2-instigated breast tumour growth in vivo and placental extravillous trophoblast (EVT) invasion in vitro. Similarly, the PAR1 mutant hPar1-7A, which is unable to bind the PH domain, reduces mammary tumours and EVT invasion, endowing these motifs with physiological significance and underscoring the importance of these previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological and physiological invasion processes. PMID:26600192

  5. Pulse measurement apparatus and method

    DOEpatents

    Marciante, John R.; Donaldson, William R.; Roides, Richard G.

    2011-10-25

    An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses. An embodiment of the invention is directed to a method for increasing the dynamic range of a pulse measurement by a repetitively-gated electronic sampling device having a rated dynamic range capability, beyond the rated dynamic range of the sampling device; e.g., enhancing the dynamic range of an oscilloscope. The embodied technique can improve the SNR from about 300:1 to 1000:1. A dynamic range enhancement of four to seven bits may be achieved.

  6. Aqueous misdirection following pars plana vitrectomy and silicone oil injection

    PubMed Central

    Ghoraba, Hammouda H; Ghali, Ali Ahmed; Mansour, Hosam Othman

    2015-01-01

    Purpose To report a retrospective series of seven phakic eyes of seven patients suffering from a malignant glaucoma-like syndrome following pars plana vitrectomy and silicone oil (SO) injection. Materials and methods Seven eyes with retinal detachment treated with pars plana vitrectomy with or without scleral buckling with SO tamponade. This was followed by cataract extraction to manage the elevated intraocular pressure (IOP). Results This was a retrospective review of seven cases that received pars plana vitrectomy and SO with or without scleral buckling for different causes of retinal detachment (three were rhegmatogenous and four were tractional). After a period ranging from 1 week to 1 month, they presented with malignant glaucoma-like manifestations; high IOP, shallow axial anterior chamber, and remarkable decrease of visual acuity. Atropine eye drops and anti-glaucoma medical treatment (topical and systemic) had been tried but failed to improve the condition. Dramatic decrease of IOP and deepening of the axial anterior chamber was observed in all cases in the first postoperative day after phacoemulsification and posterior chamber foldable intraocular lens implantation with posterior capsulotomy. Conclusion Aqueous misdirection syndrome may be observed following pars plana vitrectomy and SO tamponade. This must be differentiated from other causes of post vitrectomy glaucoma. Cataract extraction with posterior capsulotomy controls the condition. PMID:26056429

  7. The Pars Triangularis in Dyslexia and ADHD: A Comprehensive Approach

    ERIC Educational Resources Information Center

    Kibby, Michelle Y.; Kroese, Judith M.; Krebbs, Hillery; Hill, Crystal E.; Hynd, George W.

    2009-01-01

    Limited research has been conducted on the structure of the pars triangularis (PT) in dyslexia despite functional neuroimaging research finding it may play a role in phonological processing. Furthermore, research to date has not examined PT size in ADHD even though the right inferior frontal region has been implicated in the disorder. Hence, one…

  8. Radiological impact of Par Pond drawdown from liquid effluent pathways

    SciTech Connect

    Carlton, W.H.; Hamby, D.M.

    1991-10-25

    The water level of Par Pond has been lowered over the past several months to reduce the effects in the event of catastrophic dam failure while assessing the condition of the dam and determining if repairs are necessary. In lowering the level of Par Pond, 60 billion liters of water containing low levels of tritium and cesium-137 were discharged to several onsite streams. SRS surface streams flow to the Savannah River. An assessment made to determine the total amount of tritium and Cs-137 discharged and to estimate the consequences to downstream Savannah River users. It is estimated that a total of 160 curies of tritium were displaced from Par Pond to the Savannah River between June 28, 1991 and September 19, 1991. This release could hypothetically result in a maximum individual dose of 3. 2{times}10{sup {minus}4} mrem and a total (80-km and drinking water populations) population dose of 1.4{times}10{sup {minus}2} person-rem. Likewise, a maximum individual dose of 5.0{times}10{sup {minus}2} mrem and a total population dose of 1.7{times}10{sup {minus}1} person- rem are predicted as a result of an estimated 0.21 curies of Cs-137 being discharged from Par Pond to the Savannah River.

  9. Par Pond vegetation status summer 1995 - July survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-07-01

    A survey of the emergent shoreline aquatic plant, communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily (Nymphaea odorata), and watershield (Brasenia schreberi) are now extensive and well established. In addition, within isolated coves, extensive beds of water lilies and spike-rush (Eleocharis sp.) are common. Cattail occurrence has increased since refill, but large beds common to Par Pond prior to the drawdown have not formed. Invasion of willow (Salix sp.) and red maple (Acer rubrum) occurred along the lake shoreline during drawdown. The red maples along the present shoreline are beginning to show evidence of stress and mortality from flooding over the past four months. Some of the willows appear to be stressed as well. The loblolly pines (Pinus taeda), which were flooded in all but the shallow shoreline areas, are now dead. Future surveys are planned for the growing seasons of 1995, 1996, and 1997, along with the evaluation of satellite data for mapping the areal extent of the macrophyte beds of Par Pond.

  10. BOREAS RSS-10 TOMS Circumpolar One-Degree PAR Images

    NASA Technical Reports Server (NTRS)

    Dye, Dennis G.; Holben, Brent; Nickeson, Jaime (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-10 team investigated the magnitude of daily, seasonal, and yearly variations of Photosynthetically Active Radiation (PAR) from ground and satellite observations. This data set contains satellite estimates of surface-incident PAR (400-700 nm, MJ/sq m) at one-degree spatial resolution. The spatial coverage is circumpolar from latitudes of 41 to 66 degrees north. The temporal coverage is from May through September for years 1979 through 1989. Eleven-year statistics are also provided: (1) mean, (2) standard deviation, and (3) coefficient of variation for 1979-89. The PAR estimates were derived from the global gridded ultraviolet reflectivity data product (average of 360, 380 nm) from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS). Image mask data are provided for identifying the boreal forest zone, and ocean/land and snow/ice-covered areas. The data are available as binary image format data files. The PAR data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  11. Pulsed spallation Neutron Sources

    SciTech Connect

    Carpenter, J.M.

    1994-12-31

    This paper reviews the early history of pulsed spallation neutron source development at Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provides a few examples of applications in fundamental condensed matter physics, materials science and technology.

  12. Pulsed spallation neutron sources

    SciTech Connect

    Carpenter, J.M.

    1996-05-01

    This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

  13. Pulse magnetic welder

    DOEpatents

    Christiansen, D.W.; Brown, W.F.

    1984-01-01

    A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.

  14. LED flicker pulsing

    NASA Astrophysics Data System (ADS)

    Johnson, Mark A.; Cote, Paul J.

    2001-08-01

    There is need to replace hazardous radioluminescent light sources with a means of illumination that is environmentally friendly. This paper describes an electronic source that was developed as a potential candidate to replace low intensity tritium in a military system. It employs an LED for illumination and a 3-volt coin cell battery as a power source. This new light source is electronically invisible, requires minimal maintenance, and provides the lowest practical illumination to preclude detection by optical means. The low intensity requires that the LED be driven at DC current levels resulting in poor luminous efficiency. Therefore, in an effort to maximize battery life, the LED is pulsed into a more optically efficient mode of operation. However, conventional pulsing techniques are not employed because of concerns the electronics could be identified by conspicuous power spectral density (PSD) components in the electromagnetic spectrum generated by a pulsed LED. Therefore, flicker noise concepts have been employed to efficiently drive the LED while generating a virtually undetectable spectral signature. Although ideally the pulse durations, magnitudes, and spacings should be random, a significant reduction in conspicuous PSD components can be achieved when imposing practical constraints. The dominant components of the power spectrum are significantly reduced using fixed pulse durations and magnitudes while varying only the pulse spacing. The mean duty cycle is set to provide the same effective illumination as DC operation while generating a PSD normally associated with natural phenomena.

  15. A versatile pulse programmer for pulsed nuclear magnetic resonance spectroscopy.

    NASA Technical Reports Server (NTRS)

    Tarr, C. E.; Nickerson, M. A.

    1972-01-01

    A digital pulse programmer producing the standard pulse sequences required for pulsed nuclear magnetic resonance spectroscopy is described. In addition, a 'saturation burst' sequence, useful in the measurement of long relaxation times in solids, is provided. Both positive and negative 4 V trigger pulses are produced that are fully synchronous with a crystal-controlled time base, and the pulse programmer may be phase-locked with a maximum pulse jitter of 3 ns to the oscillator of a coherent pulse spectrometer. Medium speed TTL integrated circuits are used throughout.

  16. Results of peripheral laser photocoagulation in pars planitis.

    PubMed Central

    Pulido, J S; Mieler, W F; Walton, D; Kuhn, E; Postel, E; Hartz, A; Jampol, L M; Weinberg, D V; Logani, S

    1998-01-01

    PURPOSE: To determine the effect of peripheral retinal laser photocoagulation (PLP) on visual acuity, intraocular inflammation, and other ocular findings, including retinal neovascularization in eyes with pars planitis. METHODS: A retrospective chart review of eyes with pars planitis that had undergone PLP. RESULTS: Twenty-two eyes in 17 patients with pars planitis had undergone treatment with PLP at 2 centers. The mean age at the time of treatment was 19.3 years. Following treatment, mean follow-up was 16.3 months (range, 6 to 37 months). Mean visual acuity was 20/60 preoperatively and 20/50 postoperatively. This level of improvement was not statistically significant (P > .10), but there was a statistically significant decrease in the use of corticosteroids between the preoperative examination and the last postoperative examination (86% versus 27%, P < .05). There was also a statistically significant decrease in vitritis at the last follow-up (P = .0008) and a decrease in neovascularization of the vitreous base (P = .03) and in clinically apparent cystoid macular edema (P = .02). Epiretinal membranes were noted in 23% of eyes preoperatively and in 45% of eyes postoperatively. Only one of these epiretinal membranes was considered to be visually significant. One eye developed a tonic dilated pupil, which slowly improved. CONCLUSIONS: Although the long-term natural history of clinical findings in pars planitis is not well documented, PLP appears to decrease the need for corticosteroids while stabilizing visual acuity. It also appears to decrease vitreous inflammation. PLP has few complications and should be considered in patients with pars planitis who are unresponsive or have adverse reactions to corticosteroids. PMID:10360286

  17. The role of pars flaccida in human middle ear sound transmission.

    PubMed

    Aritomo, H; Goode, R L; Gonzalez, J

    1988-04-01

    The role of the pars flaccida in middle ear sound transmission was studied with the use of twelve otoscopically normal, fresh, human temporal bones. Peak-to-peak umbo displacement in response to a constant sound pressure level at the tympanic membrane was measured with a noncontacting video measuring system capable of repeatable measurements down to 0.2 micron. Measurements were made before and after pars flaccida modifications at 18 frequencies between 100 and 4000 Hz. Four pars flaccida modifications were studied: (1) acoustic insulation of the pars flaccida to the ear canal with a silicone rubber baffle, (2) stiffening the pars flaccida with cyanoacrylate cement, (3) decreasing the tension of the pars flaccida with a nonperforating incision, and (4) perforation of the pars flaccida. All of the modifications (except the perforation) had a minimal effect on umbo displacement; this seems to imply that the pars flaccida has a minor acoustic role in human beings. PMID:3132684

  18. Plasmas and Short-Pulse, High-Intensity Lasers

    NASA Astrophysics Data System (ADS)

    Clark, Thomas

    1999-11-01

    Many of the applications of short-pulse, high-intensity laser systems, including coherent UV and X-ray generation, compact particle accelerators, and non-perturbative nonlinear optics as well as the study of laser-matter interaction physics, require large intensity-interaction length products. In recent years, plasma structures resulting from the hydrodynamic evolution of laser-produced plasma filaments have proven to be attractive media for guiding pulses with peak powers approaching the terawatt level over lengths many times the vacuum Rayleigh range. The hydrodynamics of plasma waveguides have been characterized using time- and space-resolved interferometry measurements of electron density profiles. The laser-driven ionization and heating phase of the plasma filament creation is followed by hot electron driven plasma expansion. Density profiles suitable for optical guiding develop within the first few hundred picoseconds after plasma creation, during which rapid cooling occurs. At longer times the plasma expansion closely follows that of a cylindrical blast wave, with further cooling due to expansion work. The observed guided intensity profiles of end-coupled and tunnel-coupled pulses compare favorably with calculations of the quasi-bound waveguide modes based on the measured electron density profiles. Time- and space-resolved electron density measurements of a laser-driven concentric implosion were also performed. The implosion is the result of the interaction of a second laser pulse with an existing plasma waveguide. The two-pulse absorption and ionization significantly exceed that due to a single pulse of the same total energy. The author would like to acknowledge the significant contributions of Prof. Howard M. Milchberg to the work being presented.

  19. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, R.B.

    1985-08-15

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  20. Pulse shaping with transmission lines

    DOEpatents

    Wilcox, Russell B.

    1987-01-01

    A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

  1. Efficient optical pulse stacker system

    DOEpatents

    Seppala, Lynn G.; Haas, Roger A.

    1982-01-01

    Method and apparatus for spreading and angle-encoding each pulse of a multiplicity of small area, short pulses into several temporally staggered pulses by use of appropriate beam splitters, with the optical elements being arranged so that each staggered pulse is contiguous with one or two other such pulses, and the entire sequence of stacked pulses comprising a single, continuous long pulse. The single long pulse is expanded in area, and then doubly passed through a nonstorage laser amplifier such as KrF. After amplification, the physically separated, angle-encoded and temporally staggered pulses are recombined into a single pulse of short duration. This high intensity output beam is well collimated and may be propagated over long distance, or used for irradiating inertial confinement fusion targets.

  2. High voltage pulse generator

    DOEpatents

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  3. Relativistic Guiding Center Equations

    SciTech Connect

    White, R. B.; Gobbin, M.

    2014-10-01

    In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.

  4. Sensor Characteristics Reference Guide

    SciTech Connect

    none,

    2013-04-01

    The purpose of the guide is to inform building owners and operators of the current status, capabilities, and limitations of sensor technologies. It is hoped that this guide will aid in the design and procurement process and result in successful implementation of building sensor and control systems. DOE will also use this guide to identify research priorities, develop future specifications for potential market adoption, and provide market clarity through unbiased information.

  5. Photoconductive circuit element pulse generator

    DOEpatents

    Rauscher, Christen

    1989-01-01

    A pulse generator for characterizing semiconductor devices at millimeter wavelength frequencies where a photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test.

  6. The Role of Prostate Apoptosis Response-4 (Par-4) in Mycobacterium tuberculosis Infected Macrophages.

    PubMed

    Han, Ji-Ye; Lim, Yun-Ji; Choi, Ji-Ae; Lee, Jung-Hwan; Jo, Sung-Hee; Oh, Sung-Man; Song, Chang-Hwa

    2016-01-01

    Prostate apoptosis response-4 (Par-4) is a tumor suppressor protein that forms a complex with glucose-regulated protein 78 (GRP78) to induce apoptosis. Previously, we reported that ER stress-induced apoptosis is a critical host defense mechanism against Mycobacterium tuberculosis (Mtb). We sought to understand the role of Par-4 during ER stress-induced apoptosis in response to mycobacterial infection. Par-4 and GRP78 protein levels increased in response Mtb (strain: H37Ra) infection. Furthermore, Par-4 and GRP78 translocate to the surface of Mtb H37Ra-infected macrophages and induce apoptosis via caspase activation. NF-κB activation, Mtb-mediated ER stress, and Par-4 production were significantly diminished in macrophages with inhibited ROS production. To test Par-4 function during mycobacterial infection, we analyzed intracellular survival of Mtb H37Ra in macrophages with Par-4 overexpression or knockdown. Mtb H37Ra growth was significantly reduced in Par-4 overexpressing macrophages and increased in knockdown macrophages. We also observed increased Par-4, GRP78, and caspases activation in Bacillus Calmette-Guérin (BCG)-infected prostate cancer cells. Our data demonstrate that Par-4 is associated with ER stress-induced apoptosis resulting in reduced intracellular survival of mycobacteria. BCG treatment increases Par-4-dependent caspase activation in prostate cancer cells. These results suggest ER stress-induced Par-4 acts as an important defense mechanism against mycobacterial infection and regulates cancer. PMID:27552917

  7. The Role of Prostate Apoptosis Response-4 (Par-4) in Mycobacterium tuberculosis Infected Macrophages

    PubMed Central

    Han, Ji-Ye; Lim, Yun-Ji; Choi, Ji-Ae; Lee, Jung-hwan; Jo, Sung-Hee; Oh, Sung-Man; Song, Chang-Hwa

    2016-01-01

    Prostate apoptosis response-4 (Par-4) is a tumor suppressor protein that forms a complex with glucose-regulated protein 78 (GRP78) to induce apoptosis. Previously, we reported that ER stress-induced apoptosis is a critical host defense mechanism against Mycobacterium tuberculosis (Mtb). We sought to understand the role of Par-4 during ER stress-induced apoptosis in response to mycobacterial infection. Par-4 and GRP78 protein levels increased in response Mtb (strain: H37Ra) infection. Furthermore, Par-4 and GRP78 translocate to the surface of Mtb H37Ra-infected macrophages and induce apoptosis via caspase activation. NF-κB activation, Mtb-mediated ER stress, and Par-4 production were significantly diminished in macrophages with inhibited ROS production. To test Par-4 function during mycobacterial infection, we analyzed intracellular survival of Mtb H37Ra in macrophages with Par-4 overexpression or knockdown. Mtb H37Ra growth was significantly reduced in Par-4 overexpressing macrophages and increased in knockdown macrophages. We also observed increased Par-4, GRP78, and caspases activation in Bacillus Calmette-Guérin (BCG)-infected prostate cancer cells. Our data demonstrate that Par-4 is associated with ER stress-induced apoptosis resulting in reduced intracellular survival of mycobacteria. BCG treatment increases Par-4-dependent caspase activation in prostate cancer cells. These results suggest ER stress-induced Par-4 acts as an important defense mechanism against mycobacterial infection and regulates cancer. PMID:27552917

  8. Is There an "F" in Your PAR? Understanding, Teaching and Doing Action Research

    ERIC Educational Resources Information Center

    Lorenzetti, Liza; Walsh, Christine Ann

    2014-01-01

    Participatory Action Research (PAR) is increasingly recognized within academic research and pedagogy. What are the benefits of including feminism within participatory action research and teaching? In responding to this question, we discuss the similarities and salient differences between PAR and feminist informed PAR (FPAR). There are eight themes…

  9. ParA resolvase catalyzes site-specific excision of DNA from the Arabidopsis genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The small serine resolvase ParA from bacterial plasmids RK2 and RP4 catalyzes the recombination of two identical 133 bp recombination sites known as MRS. Previously, we reported that ParA is active in the fission yeast Schizosaccharomyces pombe. In this work, the parA recombinase gene was placed un...

  10. Detection of suPAR in the Saliva of Healthy Young Adults: Comparison with Plasma Levels

    PubMed Central

    Gustafsson, Anna; Ajeti, Vjosa; Ljunggren, Lennart

    2011-01-01

    The soluble urokinase plasminogen activator receptor (suPAR) has been detected in blood, plasma, serum, urine, ovarian cystic fluid, and cerebrospinal fluid. Elevated suPAR levels in plasma have been associated with negative outcomes in various diseases, such as bacteremia, sepsis, SIRS, cardiovascular disease, cancer, and tuberculosis. The primary aim of this study was to investigate whether suPAR can be detected in saliva from healthy individuals and thus, if saliva suPAR can be related to plasma suPAR, CRP, BMI, or gender. Blood and unstimulated whole saliva was collected from 20 healthy individuals (10 female and 10 male, median age of 28 years; range 21–41). CRP and suPAR were measured with ELISA in saliva and serum/plasma. suPAR was detected in all saliva samples in the 5.2–28.1 ng/mL range, with a median value of 17.1 ng/mL. Saliva suPAR was significantly higher (P < 0.001) but not correlated to plasma suPAR in healthy young adults with normal plasma suPAR levels. suPAR and CRP levels were correlated in blood but not in saliva. No correlation was found between BMI, age, or gender and suPAR in saliva. PMID:22084570

  11. HydroPulse Drilling

    SciTech Connect

    J.J. Kolle

    2004-04-01

    Tempress HydroPulse{trademark} tool increases overbalanced drilling rates by generating intense suction pulses at the drill bit. This report describes the operation of the tool; results of pressure drilling tests, wear tests and downhole drilling tests; and the business case for field applications. The HydroPulse{trademark} tool is designed to operate on weighted drilling mud at conventional flow rates and pressures. Pressure drilling tests confirm that the HydroPulse{trademark} tool provides 33% to 200% increased rate of penetration. Field tests demonstrated conventional rotary and mud motor drilling operations. The tool has been operated continuous for 50 hours on weighted mud in a wear test stand. This level of reliability is the threshold for commercial application. A seismic-while-drilling version of the tool was also developed and tested. This tool was used to demonstrate reverse vertical seismic profiling while drilling an inclined test well with a PDC bit. The primary applications for the HydroPulse{trademark} tool are deep onshore and offshore drilling where rate of penetration drives costs. The application of the seismic tool is vertical seismic profiling-while-drilling and look-ahead seismic imaging while drilling.

  12. Giant radio pulses

    NASA Astrophysics Data System (ADS)

    Kondratiev, Vladislav

    Rotation-powered radio pulsars exhibit a remarkably diverse spectrum of variability with characteristic time scales from days and even years (intermittent pulsars) to minutes-seconds (nulling) and (sub-)microseconds. The latter time scales are associated with the phenomenon of giant pulses (GPs) and micropulses. The story of GPs started in 1968, when Staelin and Reifenstein discovered the Crab pulsar through its spectacularly bright radio pulses. To date, only seven pulsars out of more than 2200 are known to show GP emission, namely the pulsars B0531+21, B1937+21, B0540-69, B1821-24, B1957+20, J0218+4232, and B1820-30A. Giant pulses are characterized by large energies (more than ten times of the energy of the average pulse), short durations, power-law energy distribution, specific rotational phase of occurrence, high degree of polarization, and accompanying high-energy radiation. Large energies of GPs and coincidence of their phase of occurrence with peaks of high-energy profiles hint at the same mechanism of radio GP and high-energy emission. The correlation of Crab pulsar GPs with optical, X-ray and gamma-ray photons was studied for the past 20 years, with only radio/optical link confirmed so far. In my talk I will present the summary of the observational evidence of radio GPs and give an overview of theoretical advances on giant-pulse emission mechanism.

  13. ParCAT: A Parallel Climate Analysis Toolkit

    NASA Astrophysics Data System (ADS)

    Haugen, B.; Smith, B.; Steed, C.; Ricciuto, D. M.; Thornton, P. E.; Shipman, G.

    2012-12-01

    Climate science has employed increasingly complex models and simulations to analyze the past and predict the future of our climate. The size and dimensionality of climate simulation data has been growing with the complexity of the models. This growth in data is creating a widening gap between the data being produced and the tools necessary to analyze large, high dimensional data sets. With single run data sets increasing into 10's, 100's and even 1000's of gigabytes, parallel computing tools are becoming a necessity in order to analyze and compare climate simulation data. The Parallel Climate Analysis Toolkit (ParCAT) provides basic tools that efficiently use parallel computing techniques to narrow the gap between data set size and analysis tools. ParCAT was created as a collaborative effort between climate scientists and computer scientists in order to provide efficient parallel implementations of the computing tools that are of use to climate scientists. Some of the basic functionalities included in the toolkit are the ability to compute spatio-temporal means and variances, differences between two runs and histograms of the values in a data set. ParCAT is designed to facilitate the "heavy lifting" that is required for large, multidimensional data sets. The toolkit does not focus on performing the final visualizations and presentation of results but rather, reducing large data sets to smaller, more manageable summaries. The output from ParCAT is provided in commonly used file formats (NetCDF, CSV, ASCII) to allow for simple integration with other tools. The toolkit is currently implemented as a command line utility, but will likely also provide a C library for developers interested in tighter software integration. Elements of the toolkit are already being incorporated into projects such as UV-CDAT and CMDX. There is also an effort underway to implement portions of the CCSM Land Model Diagnostics package using ParCAT in conjunction with Python and gnuplot. Par

  14. Enhanced particle guiding using supercontinuum radiation

    NASA Astrophysics Data System (ADS)

    Fischer, Pascal; Carruthers, Antonia E.; Volke-Sepulveda, Karen; Wright, Ewan M.; Little, Helen; Brown, Christian T. A.; Sibbett, Wilson; Dholakia, Kishan

    2006-08-01

    We demonstrate the use of supercontinuum radiation to provide enhanced guiding distances of microscopic particles compared to the standard continuous wave or femtosecond lasers. Our technique relies on the chromatic aberration of the lens used to form an elongated focal region within which guiding takes place. The resulting beam profile has been modelled and shows that for a Gaussian input beam, the intensity profile after the lens can be considered as a sum of Gaussians, one for each wavelength but with varying focal position due to dispersion. Our experimental investigations compare radiation from continuous wave (bandwidth <1nm) and femtosecond pulsed (bandwidth > 100nm) lasers as well as supercontinuum radiation (bandwidth > 450nm) and show good agreement with theory.

  15. Science: Grade 7. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  16. Science: Grade 9. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  17. Science: Grade 6. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  18. Science: Grade 5. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  19. Science: Grade 8. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  20. Science: Grade 2. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education and Training, Winnipeg.

    This guide is one of a set of 10 science guides, each covering a separate grade in Manitoba, together covering kindergarten through grade 9. The guides have been designed to provide a framework for building scientific concepts and developing the learning of process skills. They replace an earlier set of guides dated 1979. Each guide is essentially…

  1. Pulse shaping system

    DOEpatents

    Skeldon, M.D.; Letzring, S.A.

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses. 8 figs.

  2. Pulse shaping system

    DOEpatents

    Skeldon, Mark D.; Letzring, Samuel A.

    1999-03-23

    Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses.

  3. Pulse power linac

    DOEpatents

    Villa, Francesco

    1990-01-01

    A linear acceleration for charged particles is constructed of a plurality of transmission line sections that extend between a power injection region and an accelerating region. Each line section is constructed of spaced plate-like conductors and is coupled to an accelerating gap located at the accelerating region. Each gap is formed between a pair of apertured electrodes, with all of the electrode apertures being aligned along a particle accelerating path. The accelerating gaps are arranged in series, and at the injection region the line sections are connected in parallel. At the injection region a power pulse is applied simultaneously to all line sections. The line sections are graduated in length so that the pulse reaches the gaps in a coordinated sequence whereby pulse energy is applied to particles as they reach each of the gaps along the accelerating path.

  4. PULSE AMPLITUDE ANALYZERS

    DOEpatents

    Gray, G.W.; Jensen, A.S.

    1958-06-01

    An analyzer system incorporating a cathode-ray tube and linearly spaced targets masked by a plate having slits at points corresponding to the location of the targets is described. The advantages of the system include reduction in the required amplified band width and also the reduction in possible double counting of a pulse by striking two targets. The system comprises integrating means for each pulse, the signal from which is applied to a pair of deflection plates, and a control circuit for turning on the electron beam when the pulse has almost reached its maximum value. The mask prevents the beam from overlapping on a target adjacent to the proper one, while a control circuit responsive to the target output signals acts to cut off the beam immediately after the beam strikes a target to permit the beam to impinge on only one target.

  5. Discharge pulse phenomenology

    NASA Technical Reports Server (NTRS)

    Frederickson, A. R.

    1985-01-01

    A model was developed which places radiation induced discharge pulse results into a unified conceptual framework. Only two phenomena are required to interpret all space and laboratory results: (1) radiation produces large electrostatic fields inside insulators via the trapping of a net space charge density; and (2) the electrostatic fields initiate discharge streamer plasmas similar to those investigated in high voltage electrical insulation materials; these streamer plasmas generate the pulsing phenomena. The apparent variability and diversity of results seen is an inherent feature of the plasma streamer mechanism acting in the electric fields which is created by irradiation of the dielectrics. The implications of the model are extensive and lead to constraints over what can be done about spacecraft pulsing.

  6. Pulsed welding plasma source

    NASA Astrophysics Data System (ADS)

    Knyaz'kov, A.; Pustovykh, O.; Verevkin, A.; Terekhin, V.; Shachek, A.; Tyasto, A.

    2016-04-01

    It is shown that in order to form the current pulse of a near rectangular shape, which provides conversion of the welding arc into a dynamic mode, it is rational to connect a forming element made on the basis of an artificial forming line in series to the welding DC circuit. The paper presents a diagram of a pulsed device for welding with a non-consumable electrode in argon which was developed using the forming element. The conversion of the arc into the dynamic mode is illustrated by the current and voltage oscillograms of the arc gap and the dynamic characteristic of the arc within the interval of one pulse generation time in the arc gap. The background current travels in the interpulse interval.

  7. Pulsed eddy current testing

    NASA Astrophysics Data System (ADS)

    Workman, G. L.

    1980-10-01

    Since a large number of the procedures used for inspecting the external tank are concerned with determining flaws in welds, there is a need to develop an inspection technique, which can be automated, to determine flaws in welds and structures with complex geometries. Techniques whereby an eddy current is generated in a metallic material and the changes in the circuit parameters due to material differences are observed, were chosen as one possible approach. Pulsed eddy current and its relationship to multifrequency techniques is discussed as well as some preliminary results obtained from observing pulsed waveforms with apparatus and algorithms currently in use for ultrasonic testing of welds. It can be shown the pulsed eddy current techniques can provide similar results, can eliminate some of the noncritical parameters affecting the eddy current signals, and can facilitate in the detection of critical parameter such as flaws, subsurface voids, and corrosion.

  8. Laser pulse sampler

    DOEpatents

    Vann, Charles

    1998-01-01

    The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera.

  9. Laser pulse sampler

    DOEpatents

    Vann, C.

    1998-03-24

    The Laser Pulse Sampler (LPS) measures temporal pulse shape without the problems of a streak camera. Unlike the streak camera, the laser pulse directly illuminates a camera in the LPS, i.e., no additional equipment or energy conversions are required. The LPS has several advantages over streak cameras. The dynamic range of the LPS is limited only by the range of its camera, which for a cooled camera can be as high as 16 bits, i.e., 65,536. The LPS costs less because there are fewer components, and those components can be mass produced. The LPS is easier to calibrate and maintain because there is only one energy conversion, i.e., photons to electrons, in the camera. 5 figs.

  10. Pulsed neutron detector

    DOEpatents

    Robertson, deceased, J. Craig; Rowland, Mark S.

    1989-03-21

    A pulsed neutron detector and system for detecting low intensity fast neutron pulses has a body of beryllium adjacent a body of hydrogenous material the latter of which acts as a beta particle detector, scintillator, and moderator. The fast neutrons (defined as having En>1.5 MeV) react in the beryllium and the hydrogenous material to produce larger numbers of slow neutrons than would be generated in the beryllium itself and which in the beryllium generate hellium-6 which decays and yields beta particles. The beta particles reach the hydrogenous material which scintillates to yield light of intensity related to the number of fast neutrons. A photomultiplier adjacent the hydrogenous material (scintillator) senses the light emission from the scintillator. Utilization means, such as a summing device, sums the pulses from the photo-multiplier for monitoring or other purposes.

  11. Laser wake-field acceleration in pre-formed plasma channel created by pre-pulse pedestal of terawatt laser pulse

    SciTech Connect

    Sanyasi Rao, Bobbili; Chakera, Juzer Ali; Naik, Prasad Anant; Kumar, Mukund; Gupta, Parshotam Dass

    2011-09-15

    The role of nanosecond duration pre-pulse pedestal (Amplified Spontaneous Emission (ASE) pre-pulse) in the propagation of 45 fs, 4 TW Ti:Sapphire laser pulse through a helium gas jet target has been investigated. We observed that the pre-pulse pedestal of about 1 ns duration and intensity 3 x 10{sup 12} W/cm{sup 2} creates pre-formed plasma with optical guiding channel like structure in the gas-jet at density around 3 x 10{sup 19} cm{sup -3}. Guiding of the 45 fs laser pulse (I{sub L} = 3 x 10{sup 18} W/cm{sup 2}) in the pre-formed plasma channel, over a distance much longer than the Rayleigh length was also observed. The guiding of the laser pulse resulted in the generation of high energy electron beam by laser wake-field acceleration of self-injected electrons. The accelerated electron beam was quasi-monoenergetic with peak energy up to 50 MeV, low divergence in the range of 3-6 mrad, and bunch charge up to 100 pC.

  12. Channel Guided Standard LWFA (CGSL) Project

    SciTech Connect

    Hafizi, B.; Zigler, A.

    2006-03-04

    During the project we have demonstrated control of several important parameters of capillary channels. We achieved the required profiles for guiding, we have demonstrated channels in density range between 10{sup 17}-10{sup 19}cm{sup -3} in both short and long capillaries. The plasma temperature and density profiles were measured in both radial and longitudinal directions. The Boron Nitride capillary has provided a guiding medium that can withstand more than 1000 shots. The laser ignition of capillary discharge provided reliable almost jitter free approach. Both laser and experimental set up were upgraded. The laser system upgrade included development of a 10 TW Ti-sapphire laser facility that will be used for acceleration experiments instead T cube. We have conducted high intensity (above 10{sup 17}W/cm{sup 2}) guiding experiments through various capillaries. The concerns related to influence of relatively high current density flow through capillary on the injected electrons were studied extensively by us both theoretically and experimentally using a simple injection method. The method is based on the interaction of a high intensity laser pulse with a thin wire placed near capillary entrance. The influence of magnetic fields was found to be insignificant. Using this method we have studied transport of electrons though capillary discharge. We have simulated beam injection into a channel guided LWFA and found that under certain conditions the injected electron distribution can be very broad. Finally, prior to the staging of the capillary based accelerators, we performed a proof-of-principal experiment on staged optical injection and laser wakefield acceleration using two different short laser pulses focused into two spatially separated gas jets.

  13. Pulsed NMR spectroscopy

    NASA Technical Reports Server (NTRS)

    Burum, D. P.; Elleman, D. D.; Rhim, W.

    1978-01-01

    Method gives results approximating those of classical continuous-irradiation method but in less time. Method also makes it possible to measure chemical shifts and spin-lattice relaxation times with improved sensitivity. Equipment can be used for adiabatic demagnetization experiments, measurements of rotating-frame spin/lattice relaxation times, and accurate measurements of exact resonance points. When measuring relaxation times, pulse technique can be very effective since pulses may be limited in amplitude and length to prevent spin system from being driven into saturation.

  14. Pulse Propagation in Phaseonium

    NASA Astrophysics Data System (ADS)

    Rahman, Ashiqur; Eberly, J. H.

    1996-05-01

    Phaseonium [1] is a medium where the quantum atomic phase is held fixed for long times compared with various relaxation processes. In inhomogeneously broadened two-level phaseonium, we have found a new area theorem (similar to self-induced transparency [2]) for pulse propagation, where pulses of arbitrary area can be stable instead of 2π area. We will also report results for inhomogeneously broadened three-level phaseonium. Research partially supported by NSF grant PHY94-08733. [1] M.O. Scully, Phys. Rev. Lett. 55, 2802 (1985), also Quant. Opt. 6, 203 (1994). [2] S. L. McCall and E. L. Hahn, Phys. Rev. 183, 457 (1969).

  15. Minimally invasive pars approach for foraminal disc herniation.

    PubMed

    Hitchon, Patrick W; Awe, Olatilewa O; Close, Liesl; Sukkarieh, Hamdi G

    2015-07-01

    We present a retrospective cohort study on the outcome of patients with foraminal disc herniations (FDH) treated with partial pars resections using minimally invasive surgery (MIS) through a tube. FDH present a challenge due to the more lateral trajectory needed for their excision and thereby more muscle dissection and possibly facet resection. Forty patients, 19 women and 21 men with a mean age ± standard deviation of 58 ± 12 years, underwent MIS for FDH. Data on length of hospital stay, body mass index and outcomes were collected prospectively and reviewed retrospectively. Average length of stay following surgery was 1 ± 1 days. There was one wound infection and four unsatisfactory results. Using the Macnab score, good to excellent results were achieved in 89% of the patients. Based on these results, MIS surgery with partial pars resection is an attractive option in the treatment of FDH with low morbidity and short hospital stays. PMID:25882259

  16. Surgical Technology Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This surgical technology program guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a surgical technology program. The program guide is designed to relate primarily to the development of those skills needed by individuals in the field to provide services in the…

  17. Primary Art Resource Guide.

    ERIC Educational Resources Information Center

    Newton Unified School District 373, KS.

    GRADES OR AGES: Primary Grades. SUBJECT MATTER: Art. ORGANIZATION AND PHYSICAL APPEARANCE: The guide begins with a list of topics for art expression. The main body of the guide contains 15 color-coded sections on the following subjects: 1) mobiles and folded paper; 2) collage and photo montage; 3) square paper and mosaics; 4) wax paper and…

  18. Irrigation Systems. Student's Guide.

    ERIC Educational Resources Information Center

    Amarillo Coll., TX.

    This guide is intended for use by individuals preparing for a career in commercial and residential irrigation. The materials included are geared toward students who have had some experience in the irrigation business; they are intended to be presented in 10 six-hour sessions. The first two sections deal with using this guide and preparing for the…

  19. Irrigation Systems. Instructor's Guide.

    ERIC Educational Resources Information Center

    Amarillo Coll., TX.

    This guide is intended for use by licensed irrigators who wish to teach others how to design and install residential and commercial irrigation systems. The materials included in the guide have been developed under the assumption that the instructors who use it have little or no formal training as teachers. The first section presents detailed…

  20. Terry turbine controls guide

    SciTech Connect

    Golas, R.S. . Steam Turbine Motor and Generator Div.); Wheeler, K.A. )

    1990-09-01

    While utility experience with Terry turbines has been positive, controls and adjustments of controls have required frequent attention. This technical guide addresses the Terry turbine controls, such as trip system, throttle valve linkage and governors. This guide will familiarize personnel who have not had prior experience with the design, organization and setup of these control systems. This document provides instructions for a broad range of utility personnel on optimum methods for the repair, maintenance, adjustment, and troubleshooting of the Terry turbine controls. The guide includes an engineering description of the operation and prevalent failure mechanisms, preventive and predictive maintenance suggestions, repair and adjustment methods, and spare parts recommendations. This guide will be a standalone updated reference manual. It will include drawings and descriptions affecting all required maintenance on the control system, and does not cover site specific appurtenances. Included are both generic and specific recommendations for utility maintenance engineers and technicians. These recommendations will help implement an effective maintenance or upgrade program for Terry turbine controls. This guide is a valuable resource for operating history and common control related problems. The preparation of this manual included the review of the applicable INPO Standby Turbine-Driven Pump Operating Experience Compilation. Individual utilities can use this guide to review their specific maintenance practices and develop improved procedures where applicable. The guide can also be used by some utilities to upgrade their Terry turbine control system. The guide is applicable to the nuclear industry and any other industry utilizing the Terry turbine models included in the document.

  1. Oregon Trail Teacher's Guide.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC.

    The road to the U.S. West, known as the Oregon Trail, had its first real traffic in 1843 when a group of about 1000 people left Independence, Missouri and traveled west. This teacher's guide contains short descriptions of the main landmarks and stopping points that were significant along the northwest portion of the Oregon Trail. The guide is…

  2. Agriculture, Environmental Education Guide.

    ERIC Educational Resources Information Center

    Project I-C-E, Green Bay, WI.

    This agriculture guide, for use at the secondary level, is one of a series of guides, K-12, which were developed by teachers to help introduce environmental education into the total curriculum. Environmental problems are present in every community where agriculture education is offered, and therefore many agriculture teachers have included some…

  3. Business Management Course Guide.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Vocational Education.

    This course guide is designed for teaching about the U.S. business system. Students are introduced to management functions and the background knowledge/skills necessary to be a successful manager. The guide contains 10 competency goals: (1) nature of U.S. business; (2) environment of business; (3) types of business ownership; (4) management…

  4. Teacher Guide for Airbrush.

    ERIC Educational Resources Information Center

    Miklus, Samuel

    In a brief introduction, this guide identifies some of the career opportunities open to competent airbrush artists and indicates the most frequent users (technical illustrators, photo retouchers, commercial artists and designers) of the airbrush technique. The guide includes objectives for teaching airbrush, equipment and materials needed,…

  5. ACC Study Guide Series.

    ERIC Educational Resources Information Center

    Austin Community Coll., TX. Rio Grande Campus.

    Ten one-page instructional guides designed to assist Austin Community College (ACC) students in using the library and in writing research papers are presented in this series. The titles of the guides are: (1) "The Media Collection (We have more than books in the LRC)"; (2) "Encyclopedias"; (3) "Finding Books"; (4) "Finding a Dictionary or…

  6. Outdoorsman, Leaders Guide.

    ERIC Educational Resources Information Center

    Alberta Dept. of Agriculture, Edmonton.

    Intended as an activities and resource guide for the Outdoorsman Project, this leader's guide supports the project's objectives of providing opportunities for each 4-H member to experience practical and real situations in the outdoors, instilling an appreciation of the environment in the participants, and encouraging environmental awareness. The…

  7. Drafting Lab Management Guide.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Instructional Materials Lab.

    This manual was developed to guide drafting instructors and vocational supervisors in sequencing laboratory instruction and controlling the flow of work for a 2-year machine trades training program. The first part of the guide provides information on program management (program description, safety concerns, academic issues, implementation…

  8. Library Automation Style Guide.

    ERIC Educational Resources Information Center

    Gaylord Bros., Liverpool, NY.

    This library automation style guide lists specific terms and names often used in the library automation industry. The terms and/or acronyms are listed alphabetically and each is followed by a brief definition. The guide refers to the "Chicago Manual of Style" for general rules, and a notes section is included for the convenience of individual…

  9. INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    THIS LABORATORY GUIDE WAS DEVELOPED FOR AN 80-HOUR COURSE IN INDUSTRIAL RADIOGRAPHY FOR HIGH SCHOOL GRADUATES TRAINING TO BECOME BEGINNING RADIOGRAPHERS. IT IS USED IN CONJUNCTION WITH TWO OTHER VOLUMES--(1) INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE, AND (2) INUDSTRIAL RADIOGRAPHY MANUAL. THE PROGRAM WAS DEVELOPED BY A COMMITTEE OF REPRESENTATIVES…

  10. Identification and Recruitment Guide.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Compensatory Education.

    The guide contains basic information to assist local recruiters for the North Carolina migrant education project in the identification and recruitment of children eligible for the project. Eleven terms pertaining to eligibility requirements are defined, and eligibility is explained. The guide suggests and explains information sources available to…

  11. Vocational Planning Guide.

    ERIC Educational Resources Information Center

    Dyrenfurth, Michael J.; Elias, John E.

    This guide provides local vocational administrators (LVAs) with information and guidelines to plan vocational programs for their school, district, or community college. The first four chapters outline a four-step planning process. They guide the LVA through (1) establishment of vocational education's place within the community's educational…

  12. Instructional Guide for Cosmetology.

    ERIC Educational Resources Information Center

    Virginia Polytechnic Inst. and State Univ., Blacksburg. Dept. of Education.

    Intended as a tool for cosmetology teachers in Virginia public and private schools, the document is an instructional guide which offers 12 units of study, arranged in a three year course. Materials covered help prepare students for licensure in the State of Virginia and the guide is designed to cover the 1,500 hours required to be spent in the…

  13. Head Start Curriculum Guide.

    ERIC Educational Resources Information Center

    Smith, Clare Coe; And Others

    One of a series of guides for preschool teachers and aides, the book offers a Head Start curriculum guide to help achieve goals regarding social behavior, general attitudes, academic skills, health, and parent development. Information on curriculum is divided into areas of bloc time outline, classroom arrangement, building concepts (such as…

  14. Guided Reading and Motivation

    ERIC Educational Resources Information Center

    Hauptman, Allyson L.

    2012-01-01

    The purpose of this study was to determine the relationship between Guided Reading and student motivation to read across fourth, fifth, and sixth grades. The study defined literacy motivation as: (a) task value; (b) self-perceived competence; (c) students' perceptions of the Guided Reading format. Factor analysis and repeated measures ANOVAs were…

  15. Women's History Curriculum Guide.

    ERIC Educational Resources Information Center

    Ruthsdotter, Mary, Ed.; Eisenberg, Bonnie, Ed.

    This curriculum guide is designed to facilitate teachers' first efforts to introduce information about women in U.S. history. The guide promotes a multicultural awareness of women's history beginning with the Native Americans and proceeding to current issues of diversity. Activities are divided for grades 1-6 and 7-12 but may be adapted as…

  16. Welding. Student Learning Guides.

    ERIC Educational Resources Information Center

    Ridge Vocational-Technical Center, Winter Haven, FL.

    These 23 learning guides are self-instructional packets for 23 tasks identified as essential for performance on an entry-level job in welding. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline of student…

  17. Vocational Carpentry Curriculum Guide.

    ERIC Educational Resources Information Center

    Virginia Polytechnic Inst. and State Univ., Blacksburg. Dept. of Education.

    The carpentry curriculum guide was developed as a basic guide to be used by instructors in formulating their own courses of study. The material is designed for use in vocational carpentry classes at grade levels 10, 11, and 12. Planned as a two-year sequence, it incorporates 1080 class hours of instruction and emphasizes light or residential type…

  18. Measurement Practice Guide

    ERIC Educational Resources Information Center

    College and Career Readiness and Success Center, 2014

    2014-01-01

    This discussion guide is part of a larger practice guide designed to help state education agencies (SEAs) define measurement goals, select college and career readiness measures and indicators designed to support those goals, and use the data gathered with those measures and indicators to make informed decisions about college and career readiness…

  19. Personal Finance Education Guide.

    ERIC Educational Resources Information Center

    Oregon State Board of Education, Salem.

    The guide was developed to aid teachers in planning and developing programs in personal finance education which will prepare students to function as intelligent consumers. Three case studies illustrating common consumer problems are followed by the body of the guide, focusing on five major topics and incorporating economic, social, and physical…

  20. Livestock. Student Learning Guides.

    ERIC Educational Resources Information Center

    Ridge Vocational-Technical Center, Winter Haven, FL.

    These 25 learning guides are self-instructional packets for 25 tasks identified as essential for performance on an entry-level job in livestock production. Each guide is based on a terminal performance objective (task) and 1-4 enabling objectives. For each enabling objective, some or all of these materials may be presented: learning steps (outline…

  1. Conquistadors. Teaching Guide.

    ERIC Educational Resources Information Center

    Larson, Susan Booth

    This teaching guide is comprised of four interdisciplinary units dealing with the expeditions of conquistadors in the New World: (1) "Cortes and the Aztecs: Different Views of the World"; (2) "Pizarro and the Incas: The 'What Ifs?' of History"; (3) "Orellana and the Amazon: Human and Environmental Issues"; and (4) "Teaching Guide for Cabeza de…

  2. Manufacturing Technology. Curriculum Guide.

    ERIC Educational Resources Information Center

    North Dakota State Board for Vocational Education, Bismarck.

    This guide provides the basic foundation to develop a one-semester course based on the cluster concept, manufacturing technology. One of a set of six guides for an industrial arts curriculum at the junior high school level, it suggests activities that allow students (1) to become familiar with and use some of the tools, materials, and processes…

  3. Medical Assisting Learning Guides.

    ERIC Educational Resources Information Center

    Meyer, Rose

    Eight student learning guides are provided for a medical assisting program at the secondary, postsecondary, or adult level. Each learning guide is composed of these component parts: a title page that states the task, purpose, program and task numbers, estimated time, and prerequisites; an optional learning contract that includes terminal…

  4. Medical Assisting Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a medical assisting program. The program guide is designed to relate primarily to the development of those skills needed by individuals in the medical assisting field, such as medical law and ethics, typing,…

  5. Latin Curriculum Guide.

    ERIC Educational Resources Information Center

    Lee, Agnes; Stevens, Patrick

    This guide delineates the scope and sequence of Latin instruction in levels 1-3 in terms of behavioral objectives. Following a review of the Bloomington, Minnesota, school philosophy and a discussion of the design of foreign language behavioral objectives on which the guide is based, the manual discusses expected terminal behavior in the level 1…

  6. Job Search Information Guide.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton. Special Educational Services Branch.

    This guide was developed to help classroom teachers in Alberta, Canada, assist high school students in preparing for employment. (It was originally designed to accompany Alberta Job Search information presentations.) The guide contains 11 units covering the following topics: introduction, career planning, personal fact sheets, the job search,…

  7. Guide to Juvenile Restitution.

    ERIC Educational Resources Information Center

    Schneider, Anne L., Ed.

    This guide is designed to assist programs in developing, expanding, or improving restitution activities for juvenile offenders. The guide is divided into five major sections. Part I focuses on the most fundamental decisions for restitution programs: program philosophy and goals, organizational structure, location within the juvenile justice…

  8. Marketing Education Curriculum Guide.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Coll. of Agriculture and Natural Resources Education Inst.

    This curriculum guide is intended to provide a common core of competencies from which to design an effective secondary marketing education program. Introductory materials include a definition of marketing education, objectives, outline of instructional content, and questions and answers regarding the curriculum guide. These practical materials are…

  9. Learning Technology Resource Guide.

    ERIC Educational Resources Information Center

    Zugner, Lisa Crooks, Ed.

    This guide to electronic technologies resource organizations offers a broad range of information about selected projects, centers, institutions, clearinghouse activities, courseware, software, unique products and services, consortiums, panels, forums, commissioned reports, and other available resources. Three major sections make up the guide: (1)…

  10. First Business Guide.

    ERIC Educational Resources Information Center

    Small Business Administration, Washington, DC. Office of Business Development.

    This guide offers first-time business persons information as well as administrative and operational techniques for one-person business enterprises that have low initial start-up costs and low operational and overhead costs. These one-person businesses can be home based or have site locations outside the home. Included in this guide is a list of…

  11. Recycling Study Guide.

    ERIC Educational Resources Information Center

    Hallowell, Anne; And Others

    This study guide was designed to help teachers and students understand the problems surrounding solid wastes. It includes an overview of solid waste and recycling, a glossary, suggested activities and a list of resource publications, audiovisual materials and organizations. There are 19 activity suggestions included in this guide designed for use…

  12. Curriculum Guide for Agriculture.

    ERIC Educational Resources Information Center

    Oregon State Board of Education, Salem. Div. of Community Colleges and Career Education.

    Developed through a cooperative effort by industry and education, this curriculum guide outlines the basic knowledge and skills necessary for entry-level competencies in the broad field of agriculture, or for entrance into a post-high school program. This guide is one of several developed for Oregon's new approach to secondary education called…

  13. COMTASK User's Guide (Draft).

    ERIC Educational Resources Information Center

    Peterson, John C.; Newkirk-Moore, Susan

    This guide provides complete directions for searching the Computerized Task Inventory (COMTASK) database or for adding information to or modifying information in the database. (The COMTASK database contains information about jobs and the duties, tasks, and equipment needed to perform each job.) Chapter I describes the guide, its purpose, and the…

  14. French Curriculum Guide.

    ERIC Educational Resources Information Center

    Sherman, DeAnne; Serriere, Connie

    This guide delineates the scope and sequence of French instruction in grades 7-12 indicating instructional goals in terms of behavioral objectives. Following a review of the Bloomington, Minnesota, school philosophy and a discussion of the design of the foreign language behavioral objectives in the guide, the manual presents a section on French…

  15. French Language Program Guide.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    This guide presents the philosophy, goals, and objectives, as well as the scope and sequence of French instruction at four levels for the public schools of Hawaii. The emphasis is on cultural awareness and communicative competence in French. The goals, objectives, and performance expectations are presented as guides from which teachers can derive…

  16. German Language Program Guide.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    This guide presents the philosophy, goals, and objectives, as well as the scope and sequence of German instruction at four levels for the public schools of Hawaii. The emphasis is on cultural awareness and communicative competence in German. The goals, objectives, and performance expectations are presented as guides from which teachers can derive…

  17. German Curriculum Guide.

    ERIC Educational Resources Information Center

    Boehme, Robert; And Others

    This guide delineates the scope and sequence of German instruction in both junior and senior high schools indicating instructional goals in terms of behavioral objectives. Following a review of the Bloomington, Minnesota, school philosophy and a discussion of the design of the foreign language behavioral objectives in the guide, the manual…

  18. Needs Assessment Validation Guide.

    ERIC Educational Resources Information Center

    Rainone, Rocco; Kaiser, Robert

    This resource guide is intended for local school district personnel involved in planning activities for establishing educational priorities, phase two of the Local Planning and Assessment Process (LPAP). Information is presented on the development of performance indicators and the validation of perceived needs. The guide is organized in two…

  19. User's Guide for SKETCH

    NASA Technical Reports Server (NTRS)

    Hedgley, David R., Jr.

    2000-01-01

    A user's guide for the computer program SKETCH is presented on this disk. SKETCH solves a popular problem in computer graphics-the removal of hidden lines from images of solid objects. Examples and illustrations are included in the guide. Also included is the SKETCH program, so a user can incorporate the information into a particular software system.

  20. Radiologic Technology Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a radiologic technology program. The guide contains four major sections. The General Information section contains an introduction giving an overview and defining purpose and objectives; a program description,…

  1. GEOMETRY, TENTATIVE GUIDES.

    ERIC Educational Resources Information Center

    KLIER, KATHERINE M.

    PRESENTED IS A FUSED COURSE IN PLANE, SOLID, AND COORDINATE GEOMETRY. ELEMENTARY SET THEORY, LOGIC, AND THE PRINCIPLE OF SEPARATION PROVIDE UNIFYING THREADS THROUGHOUT THE TEXT. THE TWO CURRICULUM GUIDES HAVE BEEN PREPARED FOR USE WITH TWO DIFFERENT TEXTS. EITHER CURRICULUM GUIDE MAY BE USED DEPENDING UPON THE CHOICE OF THE TEACHER AND THE NEEDS…

  2. Traffic Safety Education Guide.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Curriculum Development.

    This guide, intended for administrators, curriculum developers, and teachers, provides outlines and suggestions for strategies and materials needed to achieve the goals and objectives of the safety education program. The guide covers the following topics: a broad examination of the highway system; the responsibilities highway users have toward…

  3. Curriculum Guide Construction Cluster.

    ERIC Educational Resources Information Center

    Kline, Ken

    As part of a model construction cluster curriculum development project, this guide was developed and implemented in the Beaverton (Oregon) School District. The curriculum guide contains 16 units covering the following topics: introduction to construction jobs; safety and first aid; blueprint readings; basic mathematics; site work; framing; roofing…

  4. BONES, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS GUIDE WAS DEVELOPED FOR USE WITH THE ELEMENTARY SCIENCE STUDY UNIT ON "BONES.""BONES" HAS BEEN TAUGHT IN THE FOURTH GRADE AND REQUIRES FROM 10 TO 25 LESSONS, DEPENDING ON THE NUMBER OF ACTIVITIES USED. THE GUIDE DOES NOT PROVIDE DETAILED INSTRUCTION FOR CONDUCTING CLASSES, BUT RATHER SOME POSSIBLE ACTIVITIES, AND LEAVES THE DAY-TO-DAY…

  5. Native Americans: Subject Guide.

    ERIC Educational Resources Information Center

    Bonanni, Mimmo; Etter, Patricia A.

    This annotated subject guide lists reference material that deals with Native Americans and is available in the Arizona State University Libraries. Entries were published 1933-98, but mostly in the 1980s-90s. The guide is not comprehensive, but rather a selective list of resources useful for researching a topic in a variety of fields. The guide…

  6. Hospitality Services. Curriculum Guide.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This guide, which was developed as part of Texas' home economics education program, is intended to assist teachers of a hospitality services course focusing on the food and lodging segments of the hospitality and tourism industry. The first 40% of the approximately 600-page guide consists of strategies for teaching each of 29 essential…

  7. Katimavik Participant Information Guide.

    ERIC Educational Resources Information Center

    OPCAN, Montreal (Quebec).

    The guide provides prospective participants with an overview of Katimavik, a 9-month community volunteer service and learning program for 17- to 21-year-olds sponsored since 1977 by the Canadian Government. The guide describes the application process and computerized random selection procedures; work projects, which may range from building…

  8. Traumatismes Oculaires par Petards: Bilan sur Trois Annees

    PubMed Central

    Zouaoui-Kesraoui, N.; Derdour, A.

    2009-01-01

    Summary Les accidents dus aux pétards sont des accidents graves. Leur recrudescence ces dernières années en Algérie, essentiellement durant les fêtes du Mawlid Ennabaoui (fête de la naissance du prophète), mérite à notre sens d'entreprendre des bilans exhaustifs dont celui-ci dans le but d'une sensibilisation de toutes les compétences concernées. Nous avons réuni sur trois années consécutives (2002, 2003, 2004) 60 dossiers de malades ayant subi des accidents oculaires par pétards. Nos patients sont répartis en 42 consultations pour blessures légères et 18 hospitalisations pour blessures graves. Parmi ces derniers, neuf ont présenté des complications et séquelles graves (cinq cas de cécité par atrophie du globe oculaire, trois cas de cécité cornéenne et un cas de cécité par trou maculaire). Dans tous ces cas l'incapacité permanente partielle est au minimum de 30%. Au vu de ces données nous proposons des mesures d'éducation sanitaire et une sensibilisation du grand public aux traumatismes oculaires, par le biais de mé dias appropriés: radio, télévision, affiches. PMID:21991157

  9. Radiation Guiding In a Dense, Elongated Cold-Atom Cloud

    NASA Astrophysics Data System (ADS)

    Ramos, Andira; Chen, Yun-Jhih; Maclennan, Jamie; Raithel, Georg

    2016-05-01

    Radiation guiding through a dense, elongated cold-atom cloud in a deep optical lattice created by an in-vacuum cavity has been experimentally observed. When atoms are loaded into the optical lattice, a cylindrically symmetric depletion zone surrounding the lattice location is created. This variation in atomic density gives rise to a position-dependent index of refraction which allows for a probe beam properly coupled into the atomic cloud to be guided through it. For a Hermite-Gaussian mode (HG00) , this mini fiber exhibits a transmission pattern consisting of a central feature and multiple concentric rings around it, with higher cavity modes also being accessible in the current experimental setup. Simulations that look to properly model these features are presented. This form of radiation guiding can be useful for Rydberg polariton and EIT experiments, where the atomic fiber would guide one or more trains of single-photon pulses, depending on the cavity mode.

  10. Electrostatically Guided Rydberg Positronium.

    PubMed

    Deller, A; Alonso, A M; Cooper, B S; Hogan, S D; Cassidy, D B

    2016-08-12

    We report experiments in which positronium (Ps) atoms were guided using inhomogeneous electric fields. Ps atoms in Rydberg-Stark states with principal quantum number n=10 and electric dipole moments up to 610 D were prepared via two-color two-photon optical excitation in the presence of a 670  V cm^{-1} electric field. The Ps atoms were created at the entrance of a 0.4 m long electrostatic quadrupole guide, and were detected at the end of the guide via annihilation gamma radiation. When the lasers were tuned to excite low-field-seeking Stark states, a fivefold increase in the number of atoms reaching the end of the guide was observed, whereas no signal was detected when high-field-seeking states were produced. The data are consistent with the calculated geometrical guide acceptance. PMID:27563960

  11. Electrostatically Guided Rydberg Positronium

    NASA Astrophysics Data System (ADS)

    Deller, A.; Alonso, A. M.; Cooper, B. S.; Hogan, S. D.; Cassidy, D. B.

    2016-08-01

    We report experiments in which positronium (Ps) atoms were guided using inhomogeneous electric fields. Ps atoms in Rydberg-Stark states with principal quantum number n =10 and electric dipole moments up to 610 D were prepared via two-color two-photon optical excitation in the presence of a 670 V cm-1 electric field. The Ps atoms were created at the entrance of a 0.4 m long electrostatic quadrupole guide, and were detected at the end of the guide via annihilation gamma radiation. When the lasers were tuned to excite low-field-seeking Stark states, a fivefold increase in the number of atoms reaching the end of the guide was observed, whereas no signal was detected when high-field-seeking states were produced. The data are consistent with the calculated geometrical guide acceptance.

  12. The Pars Interarticularis Stress Reaction, Spondylolysis, and Spondylolisthesis Progression

    PubMed Central

    Motley, Gina; Nyland, John; Jacobs, Jake; Caborn, David N. M.

    1998-01-01

    Objective: To review the classification, etiology, clinical and radiologic evaluation, and management of the pars interarticularis stress reaction, spondylolysis, and spondylolisthesis progression. Data Sources: Grateful Med was searched from 1980 to 1998 using the terms “spondylolysis,” “spondylolisthesis,” “female athlete” “spondylogenic,” and “pars interarticularis.” Data Synthesis: The progression from pars interarticularis stress reaction through spondylolysis to spondylolisthesis is common in adolescent athletes, and, because of hormonal influences and cheerleading and gymnastic maneuvers, females are particularly at risk. Proper diagnosis and management include a thorough evaluation, radiographs (possibly with technetium bone scan or single-photon emission computed tomography), activity modification, dietary counseling, a therapeutic exercise program focusing on proper trunk and hip muscle strength and extensibility balances, and education regarding proper back postures, positioning, lifting mechanics, and jump landings. Conclusions/Recommendations: The athletic trainer plays an integral part in managing this injury progression, particularly with identifying at-risk individuals and intervening appropriately. ImagesFigure 4. PMID:16558534

  13. ParB Partition Proteins: Complex Formation and Spreading at Bacterial and Plasmid Centromeres

    PubMed Central

    Funnell, Barbara E.

    2016-01-01

    In bacteria, active partition systems contribute to the faithful segregation of both chromosomes and low-copy-number plasmids. Each system depends on a site-specific DNA binding protein to recognize and assemble a partition complex at a centromere-like site, commonly called parS. Many plasmid, and all chromosomal centromere-binding proteins are dimeric helix-turn-helix DNA binding proteins, which are commonly named ParB. Although the overall sequence conservation among ParBs is not high, the proteins share similar domain and functional organization, and they assemble into similar higher-order complexes. In vivo, ParBs “spread,” that is, DNA binding extends away from the parS site into the surrounding non-specific DNA, a feature that reflects higher-order complex assembly. ParBs bridge and pair DNA at parS and non-specific DNA sites. ParB dimers interact with each other via flexible conformations of an N-terminal region. This review will focus on the properties of the HTH centromere-binding protein, in light of recent experimental evidence and models that are adding to our understanding of how these proteins assemble into large and dynamic partition complexes at and around their specific DNA sites. PMID:27622187

  14. Dynamic Filament Formation by a Divergent Bacterial Actin-Like ParM Protein

    PubMed Central

    Brzoska, Anthony J.; Jensen, Slade O.; Barton, Deborah A.; Davies, Danielle S.; Overall, Robyn L.; Skurray, Ronald A.; Firth, Neville

    2016-01-01

    Actin-like proteins (Alps) are a diverse family of proteins whose genes are abundant in the chromosomes and mobile genetic elements of many bacteria. The low-copy-number staphylococcal multiresistance plasmid pSK41 encodes ParM, an Alp involved in efficient plasmid partitioning. pSK41 ParM has previously been shown to form filaments in vitro that are structurally dissimilar to those formed by other bacterial Alps. The mechanistic implications of these differences are not known. In order to gain insights into the properties and behavior of the pSK41 ParM Alp in vivo, we reconstituted the parMRC system in the ectopic rod-shaped host, E. coli, which is larger and more genetically amenable than the native host, Staphylococcus aureus. Fluorescence microscopy showed a functional fusion protein, ParM-YFP, formed straight filaments in vivo when expressed in isolation. Strikingly, however, in the presence of ParR and parC, ParM-YFP adopted a dramatically different structure, instead forming axial curved filaments. Time-lapse imaging and selective photobleaching experiments revealed that, in the presence of all components of the parMRC system, ParM-YFP filaments were dynamic in nature. Finally, molecular dissection of the parMRC operon revealed that all components of the system are essential for the generation of dynamic filaments. PMID:27310470

  15. ParB Partition Proteins: Complex Formation and Spreading at Bacterial and Plasmid Centromeres.

    PubMed

    Funnell, Barbara E

    2016-01-01

    In bacteria, active partition systems contribute to the faithful segregation of both chromosomes and low-copy-number plasmids. Each system depends on a site-specific DNA binding protein to recognize and assemble a partition complex at a centromere-like site, commonly called parS. Many plasmid, and all chromosomal centromere-binding proteins are dimeric helix-turn-helix DNA binding proteins, which are commonly named ParB. Although the overall sequence conservation among ParBs is not high, the proteins share similar domain and functional organization, and they assemble into similar higher-order complexes. In vivo, ParBs "spread," that is, DNA binding extends away from the parS site into the surrounding non-specific DNA, a feature that reflects higher-order complex assembly. ParBs bridge and pair DNA at parS and non-specific DNA sites. ParB dimers interact with each other via flexible conformations of an N-terminal region. This review will focus on the properties of the HTH centromere-binding protein, in light of recent experimental evidence and models that are adding to our understanding of how these proteins assemble into large and dynamic partition complexes at and around their specific DNA sites. PMID:27622187

  16. SNMR pulse sequence phase cycling

    DOEpatents

    Walsh, David O; Grunewald, Elliot D

    2013-11-12

    Technologies applicable to SNMR pulse sequence phase cycling are disclosed, including SNMR acquisition apparatus and methods, SNMR processing apparatus and methods, and combinations thereof. SNMR acquisition may include transmitting two or more SNMR pulse sequences and applying a phase shift to a pulse in at least one of the pulse sequences, according to any of a variety cycling techniques. SNMR processing may include combining SNMR from a plurality of pulse sequences comprising pulses of different phases, so that desired signals are preserved and indesired signals are canceled.

  17. Bricklayer's Helper. Coordinator's Guide. Individualized Study Guide.

    ERIC Educational Resources Information Center

    Barnes, Bill

    This individualized, competency-based study guide is designed to assist teacher-coordinators supervising cooperative education programs for bricklayer's helpers in providing students with general information for immediate reinforcement on the job and developing an understanding of the job prior to employment. A progress chart is provided to allow…

  18. Electrician's Helper. Coordinator's Guide. Individualized Study Guide.

    ERIC Educational Resources Information Center

    Stotts, Danny

    This guide is designed to assist teacher-coordinators supervising cooperative education programs for electrician's helpers in helping students complete a set of individualized, competency-based training activities dealing with electricity and electrical circuits and equipment. The first part of the manual includes a progress chart, a study guide…

  19. Structure of the ParM filament at 8.5 Å resolution

    PubMed Central

    Gayathri, Pananghat; Fujii, Takashi; Namba, Keiichi; Löwe, Jan

    2013-01-01

    The actin-like protein ParM forms the cytomotive filament of the ParMRC system, a type II plasmid segregation system encoded by Escherichia coli R1 plasmid. We report an 8.5 Å resolution reconstruction of the ParM filament, obtained using cryo-electron microscopy. Fitting of the 3D density reconstruction with monomeric crystal structures of ParM provides insights into dynamic instability of ParM filaments. The structural analysis suggests that a ParM conformation, corresponding to a metastable state, is held within the filament by intrafilament contacts. This filament conformation of ParM can be attained only from the ATP-bound state, and induces a change in conformation of the bound nucleotide. The structural analysis also provides a rationale for the observed stimulation of hydrolysis upon polymerisation into the filament. PMID:23462100

  20. ParA resolvase catalyzes site-specific excision of DNA from the Arabidopsis genome.

    PubMed

    Thomson, James G; Yau, Yuan-Yeu; Blanvillain, Robert; Nunes, Wylla M; Chiniquy, Dawn; Thilmony, Roger; Ow, David W

    2009-04-01

    The small serine resolvase ParA from bacterial plasmids RK2 and RP4 catalyzes the recombination of two identical 133 bp recombination sites known as MRS. Previously, we reported that ParA is active in the fission yeast Schizosaccharomyces pombe. In this work, the parA recombinase gene was placed under the control of the Arabidopsis OXS3 promoter and introduced into Arabidopsis lines harboring a chromosomally integrated MRS-flanked target. The ParA recombinase excised the MRS-flanked DNA and the excision event was detected in subsequent generations in the absence of ParA, indicating germinal transmission of the excision event. The precise site-specific deletion by the ParA recombination system in planta demonstrates that the ParA recombinase can be used to remove transgenic DNA, such as selectable markers or other introduced transgenes that are no longer desired in the final product. PMID:18704739

  1. Passive and active pulse stacking scheme for pulse shaping

    DOEpatents

    Harney, Robert C.; Schipper, John F.

    1977-01-01

    Apparatus and method for producing a sequence of radiation pulses with a pulse envelope of time variation which is controllable by an external electromagnetic signal applied to an active medium or by a sectored reflector, through which the radiation passes.

  2. Pulse distortion in single-mode fibers. 3: Chirped pulses.

    PubMed

    Marcuse, D

    1981-10-15

    The theory of pulse distortion in single-mode fibers is extended to include laser sources that suffer a linear wavelength sweep (chirp) during the duration of the pulse. The transmitted pulse is expressed as a Fourier integral whose spectral function is given by an analytical expression in closed form. The rms width of the transmitted pulse is also expressed in closed form. Numerical examples illustrate the influence of the chirp on the shape and rms width of the pulse. A somewhat paradoxical situation exists. A given input pulse can be made arbitrarily short by a sufficiently large amount of chirping, and, after a given fiber length, this chirped pulse returns to its original width. But at this particular distance an unchirped pulse would be only [equiation] times longer. Thus chirping can improve the rate of data transmission by only 40%. PMID:20372221

  3. Experiments in Pulsed Ultrasonics

    ERIC Educational Resources Information Center

    Palmer, S. B.; Forster, G. A.

    1970-01-01

    Describes and apparatus designed to generate and detect pulsed ultrasonics in solids and liquids over the frequency range 1-20 MHz. Experiments are suggested for velocity of sound, elastic constant and ultrasonic attenuation measurements on various materials over a wide temperature range. The equipment should be useful for demonstration purposes.…

  4. Pulsed Plasma Thruster

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Dr. Tom Markusic, a propulsion research engineer at the Marshall Space Flight Center (MSFC), adjusts a diagnostic laser while a pulsed plasma thruster (PPT) fires in a vacuum chamber in the background. NASA/MSFC's Propulsion Research Center (PRC) is presently investigating plasma propulsion for potential use on future nuclear-powered spacecraft missions, such as human exploration of Mars.

  5. Analog pulse processor

    DOEpatents

    Wessendorf, Kurt O.; Kemper, Dale A.

    2003-06-03

    A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.

  6. Weak Radial Artery Pulse

    PubMed Central

    Venugopalan, Poothirikovil; Sivakumar, Puthuval; Ardley, Robert G.; Oates, Crispian

    2012-01-01

    We present an 11year-old boy with a weak right radial pulse, and describe the successful application of vascular ultrasound to identify the ulnar artery dominance and a thin right radial artery with below normal Doppler flow velocity that could explain the discrepancy. The implications of identifying this anomaly are discussed. PMID:22375269

  7. Pulsed electric fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

  8. Lectures on pulsed NMR

    SciTech Connect

    Pines, A.

    1988-08-01

    These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 32 refs., 56 figs.

  9. Lectures on pulsed NMR

    SciTech Connect

    Pines, A.

    1986-09-01

    These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 55 figs.

  10. Pulsed inductive HF laser

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Churkin, D. S.; Kargapol'tsev, E. S.; Demchuk, S. V.

    2016-03-01

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H2 – F2(NF3 or SF66) and He(Ne) – H2 – F2(NF3 or SF6) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%.

  11. Downhole pulse tube refrigerators

    SciTech Connect

    Swift, G.; Gardner, D.

    1997-12-01

    This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

  12. Propulsive effects of vortex coupling between parallel pulsed jets

    NASA Astrophysics Data System (ADS)

    Athanassiadis, Athanasios; Hart, Douglas

    2015-11-01

    For vehicles that use pulsed jet propulsion, nature provides inspiration for different ways to improve propulsive performance. Communities of marine invertebrates called salps improve the efficiency of cruising locomotion by aggregating into large multi-animal chains. In this process, the cylindrical animals physically connect to each other side-by-side to form an array of individual pulsed jets whose synchronous pulsing propels the entire chain forward. Some benefits of this chaining behavior can be described using existing models of pulsed jet propulsion for steady, cruising conditions. However, during unsteady conditions such as impulsive maneuvering at low speeds, it remains unclear how interactions between neighboring jets will affect the chain's propulsive performance. Using bench-top experiments, we investigate the unsteady interactions between two parallel pulsed jets. Under some conditions, the pulsed jets form vortex rings that coalesce before vortex formation is complete, coupling the hydrodynamics of the independent jets. We measure how different degrees of vortex coupling alter the energy and momentum transfer in the two-jet system. Finally, we explore the energy and momentum scalings that would guide the design of a vehicle using multi-jet maneuvering techniques. This work was supported by the Office of Naval Research.

  13. Chirped-pulse amplification of 100-fsec pulses.

    PubMed

    Pessot, M; Squier, J; Mourou, G; Harter, D J

    1989-08-01

    Chirped-pulse amplification is used to generate 2-mJ pulses of 106-fsec duration in an alexandrite amplifier. Compression of the optical pulse is achieved by using a sequence of intracavity prisms in conjunction with diffraction gratings. This allows for the compensation of both linear and quadratic contributions to the dispersion from the amplifier. PMID:19752971

  14. All about Heart Rate (Pulse)

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More All About Heart Rate (Pulse) Updated:Apr 19,2016 ... Sodium and Salt 3 Low Blood Pressure 4 All About Heart Rate (Pulse) 5 How to Eat ...

  15. Formation of discrete pulses using taper defects in photonic crystals

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Sai Venkatesh

    2016-01-01

    A two-dimensional photonic crystal based on a lattice of silicon rods in air with a photonic bandgap in the visible and near-ultraviolet spectra is proposed by removing some of the silicon rods or resizing their radii to create a monotonically varying tapered line defect, thereby pertaining to a case of structure-based nonlinearity and making it possible to operate with low input powers. By properly manipulating the length of the line defect, pulse compression and consequent adiabatic amplification are seen, along with bunching/antibunching of pulses. For certain modes of operation, field confinement is observed, and this leads to the formation of discrete pulses, or light bullets. Such a structure can be used as a multifunctional device, with some of the functionalities being optical nonpumped amplification, frequency upconversion, memory writing, matched termination, and slow wave guiding, which form the major conclusions of the work.

  16. Dual-pulse nonlinear photoacoustic technique: a practical investigation

    PubMed Central

    Tian, Chao; Xie, Zhixing; Fabiilli, Mario L.; Liu, Shengchun; Wang, Cheng; Cheng, Qian; Wang, Xueding

    2015-01-01

    The dual-pulse nonlinear photoacoustic technique is a recently developed technology based on temperature dependence of the Grüneisen parameter and involves consecutive excitations of biological tissue using two laser pulses with a short time delay. Here we review the principle of the technique and give a discussion about its technical aspects, including selection and combination of excitation laser wavelengths, determination of laser fluence, estimation of thermal relaxation function and probability of photoablation or cavitation. Comparisons between the dual-pulse technique and conventional photoacoustics as well as thermal photoacoustics are also presented. These investigations are supported by experimental results and will give a practical reference and guide for further developments of the technique. PMID:26309756

  17. Nondegenerate optical parametric chirped pulse amplifier

    DOEpatents

    Jovanovic, Igor; Ebbers, Christopher A.

    2005-03-22

    A system provides an input pump pulse and a signal pulse. A first dichroic beamsplitter is highly reflective for the input signal pulse and highly transmissive for the input pump pulse. A first optical parametric amplifier nonlinear crystal transfers part of the energy from the input pump pulse to the input signal pulse resulting in a first amplified signal pulse and a first depleted pump pulse. A second dichroic beamsplitter is highly reflective for the first amplified signal pulse and highly transmissive for the first depleted pump pulse. A second optical parametric amplifier nonlinear crystal transfers part of the energy from the first depleted pump pulse to the first amplified signal pulse resulting in a second amplified signal pulse and a second depleted pump pulse. A third dichroic beamsplitter receives the second amplified signal pulse and the second depleted pump pulse. The second depleted pump pulse is discarded.

  18. Channel Formation in Long Laser Pulse Interaction with a Helium Gas Jet

    SciTech Connect

    Malka, V.; De Wispelaere, E.; Amiranoff, F.; Baton, S.; Bonadio, R.; Coulaud, C.; Haroutunian, R.; Modena, A.; Puissant, D.; Stenz, C.; Hueller, S.; Casanova, M.

    1997-10-01

    Experimental realization of an electron density channel created by a low intensity laser in a helium gas jet is presented. The long (2.5mm) plasma channel is fully ionized and thus prevents undesirable refraction effects for propagation and guiding of a subsequent high intensity laser pulse. The channel parameters are easily controlled and well suited for laser guiding. The radial plasma expansion and the temperature evolution have been measured and compared to hydrodynamic simulations which show that the plasma expansion is governed by a thermal wave during the laser pulse. {copyright} {ital 1997} {ital The American Physical Society}

  19. Ventilation best practices guide

    SciTech Connect

    Dorgan, C.B.; Dorgan, C.E.

    1996-07-01

    The intent of this Guide is to provide utility marketing and engineering personnel with information on how to identify indoor air quality (IAQ) problems, the current standards relating to IAQ and examples of what typically causes IAQ problems in commercial buildings. The Guide is written assuming that the reader has limited knowledge of heating, ventilating and air conditioning (HVAC) systems and that they are new to the IAQ arena. Also included in the Guide is a discussion of new electric technologies which are energy efficient and maintain a high level of IAQ.

  20. Manufacturing Planning Guide

    NASA Technical Reports Server (NTRS)

    Waid, Michael

    2011-01-01

    Manufacturing process, milestones and inputs are unknowns to first-time users of the manufacturing facilities. The Manufacturing Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their project engineering personnel in manufacturing planning and execution. Material covered includes a roadmap of the manufacturing process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, products, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  1. Sequentially pulsed traveling wave accelerator

    DOEpatents

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  2. Is PAR a Good Investment? Understanding the Costs and Benefits of Teacher Peer Assistance and Review Programs

    ERIC Educational Resources Information Center

    Papay, John P.; Johnson, Susan Moore

    2012-01-01

    Peer Assistance and Review (PAR) is a local labor-management initiative designed to improve teacher quality. In PAR, expert "consulting teachers" mentor, support, and evaluate novice and underperforming veteran teachers. Evaluations under PAR can lead to dismissals. The authors examine the costs and benefits of PAR, both financial and…

  3. New Pulsed Cold Neutron Beam Line for Fundamental Nuclear Physics at LANSCE.

    PubMed

    Seo, P-N; Bowman, J D; Gericke, M; Gillis, R C; Greene, G L; Leuschner, M B; Long, J; Mahurin, R; Mitchell, G S; Penttila, S I; Peralta, G; Sharapov, E I; Wilburn, W S

    2005-01-01

    The NPDGamma collaboration has completed the construction of a pulsed cold neutron beam line on flight path12 at the Los Alamos Neutron Science Center (LANSCE). We describe the new beam line and characteristics of the beam. We report results of the moderator brightness and the guide performance measurements. FP12 has the highest pulsed cold neutron intensity for nuclear physics in the world. PMID:27308111

  4. New Pulsed Cold Neutron Beam Line for Fundamental Nuclear Physics at LANSCE

    PubMed Central

    Seo, P.-N.; Bowman, J. D.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Leuschner, M. B.; Long, J.; Mahurin, R.; Mitchell, G. S.; Penttila, S. I.; Peralta, G.; Sharapov, E. I.; Wilburn, W. S.

    2005-01-01

    The NPDGamma collaboration has completed the construction of a pulsed cold neutron beam line on flight path12 at the Los Alamos Neutron Science Center (LANSCE). We describe the new beam line and characteristics of the beam. We report results of the moderator brightness and the guide performance measurements. FP12 has the highest pulsed cold neutron intensity for nuclear physics in the world. PMID:27308111

  5. Par3 regulates invasion of pancreatic cancer cells via interaction with Tiam1.

    PubMed

    Guo, Xingjun; Wang, Min; Zhao, Yan; Wang, Xin; Shen, Ming; Zhu, Feng; Shi, Chengjian; Xu, Meng; Li, Xu; Peng, Feng; Zhang, Hang; Feng, Yechen; Xie, Yu; Xu, Xiaodong; Jia, Wei; He, Ruizhi; Jiang, Jianxin; Hu, Jun; Tian, Rui; Qin, Renyi

    2016-08-01

    The conserved polarity complex, which comprises partitioning-defective proteins Par3, Par6, and the atypical protein kinase C, affects various cell-polarization events, including assembly of tight junctions. Control of tight junction assembly is closely related to invasion and migration potential. However, as the importance of conserved polarity complexes in regulating pancreatic cancer invasion and metastasis is unclear, we investigated their role and mechanism in pancreatic cancers. We first detect that the key protein of the conserved polarity complex finds that only Par3 is down-regulated in pancreatic cancer tissues while Par6 and aPKC show no difference. What is more, Par3 tissues level was significantly and positively associated with patient overall survival. Knocking-down Par3 promotes pancreatic cancer cells invasion and migration. And Par3 requires interaction with Tiam1 to affect tight junction assembly, and then affect invasion and migration of pancreatic cancer cells. Then, we find that tight junction marker protein ZO-1 and claudin-1 are down-regulated in pancreatic cancer tissues. And the relationship of the expression of Par3 and ZO-1 in pancreatic cancer tissue is linear correlation. We establish liver metastasis model of human pancreatic cancer cells in Balb/c nude mice and find that knocking down Par3 promotes invasion and metastasis and disturbs tight junction assembly in vivo. Taken together, these results suggest that the Par3 regulates invasion and metastasis in pancreatic cancers by controlling tight junction assembly. PMID:26084985

  6. An ELISA method detecting the active form of suPAR.

    PubMed

    Zhou, Xiaolei; Xu, Mingming; Huang, Hailong; Mazar, Andrew; Iqbal, Zafar; Yuan, Cai; Huang, Mingdong

    2016-11-01

    Urokinase plasminogen activator receptor (uPAR) exists in a number of formats in human plasma, including soluble uPAR (suPAR) and uPAR fragments. We developed an ELISA method to detect specifically the active form suPAR, which binds to its natural ligand uPA. The intra CV and inter CV of this ELISA assay is 8.5% and 9.6% respectively, and the assay can recover 99.74% of added recombinant suPAR from 10% plasma. This assay is quite sensitive, capable of detecting down to 15pg/ml of suPAR, and can measure suPAR concentrations in the range of 0.031-8ng/ml with high linear relationship. Plasma samples from pregnant women were also measured for the active form of suPAR with this assay, giving an averaged level of 1.39ng/ml, slightly higher than the level of pooled plasma from healthy donors (0.96ng/ml). This study demonstrates the feasibility to measure the active form of suPAR, which will likely have value in clinical applications. PMID:27591605

  7. PAR1 is selectively over expressed in high grade breast cancer patients: a cohort study

    PubMed Central

    Hernández, Norma A; Correa, Elma; Avila, Esther P; Vela, Teresa A; Pérez, Víctor M

    2009-01-01

    Background The protease-activated receptor (PAR1) expression is correlated with the degree of invasiveness in cell lines. Nevertheless it has never been directed involved in breast cancer patients progression. The aim of this study was to determine whether PAR1 expression could be used as predictor of metastases and mortality. Methods In a cohort of patients with infiltrating ductal carcinoma studied longitudinally since 1996 and until 2007, PAR1 over-expression was assessed by immunoblotting, immunohistochemistry, and flow citometry. Chi-square and log rank tests were used to determine whether there was a statistical association between PAR1 overexpression and metastases, mortality, and survival. Multivariate analysis was performed including HER1, stage, ER and nodes status to evaluate PAR1 as an independent prognostic factor. Results Follow up was 95 months (range: 2–130 months). We assayed PAR1 in a cohort of patients composed of 136 patients; we found PAR1 expression assayed by immunoblotting was selectively associated with high grade patients (50 cases of the study cohort; P = 0.001). Twenty-nine of 50 (58%) patients overexpressed PAR1, and 23 of these (46%) developed metastases. HER1, stage, ER and PAR1 overexpression were robustly correlated (Cox regression, P = 0.002, P = 0.024 and P = 0.002 respectively). Twenty-one of the 50 patients (42%) expressed both receptors (PAR1 and HER1 P = 0.0004). We also found a statistically significant correlation between PAR1 overexpression and increased mortality (P = 0.0001) and development of metastases (P = 0.0009). Conclusion Our data suggest PAR1 overexpression may be involved in the development of metastases in breast cancer patient and is associated with undifferentiated cellular progression of the tumor. Further studies are needed to understand PAR1 mechanism of action and in a near future assay its potential use as risk factor for metastasis development in high grade breast cancer patients. PMID:19538737

  8. Myosin II Motors and F-Actin Dynamics Drive the Coordinated Movement of the Centrosome and Soma during CNS Glial-Guided Neuronal Migration

    SciTech Connect

    Solecki, Dr. David; Trivedi, Dr. Niraj; Govek, Eve-Ellen; Kerekes, Ryan A; Gleason, Shaun Scott; Hatten, Mary E

    2009-01-01

    Lamination of cortical regions of the vertebrate brain depends on glial-guided neuronal migration. The conserved polarity protein Par6{alpha} localizes to the centrosome and coordinates forward movement of the centrosome and soma in migrating neurons. The cytoskeletal components that produce this unique form of cell polarity and their relationship to polarity signaling cascades are unknown. We show that F-actin and Myosin II motors are enriched in the neuronal leading process and that Myosin II activity is necessary for leading process actin dynamics. Inhibition of Myosin II decreased the speed of centrosome and somal movement, whereas Myosin II activation increased coordinated movement. Ectopic expression or silencing of Par6{alpha} inhibited Myosin II motors by decreasing Myosin light-chain phosphorylation. These findings suggest leading-process Myosin II may function to 'pull' the centrosome and soma forward during glial-guided migration by a mechanism involving the conserved polarity protein Par6{alpha}.

  9. Guide to Insulating Sheathing

    SciTech Connect

    2007-10-11

    This guide examines new methods of enclosure designs that provide high thermal performance and long-term durability but also take opportunities to reduce material use, simplify or integrate systems and details, and potentially reduce overall initial costs of construction.

  10. Food guide plate

    MedlinePlus

    ... The new guide encourages you to eat more fruits and vegetables, whole grains, lean proteins, and low- ... that make up a healthy diet: Grains Vegetables Fruits Dairy Protein foods You should eat foods from ...

  11. Buyers' guide 2009

    SciTech Connect

    2008-12-15

    The 2009 Buyers' guide consists of a company directory, a product directory and a service directory. The company directory lists manufacturers' names, corporate addresses, telephone and fax numbers, e-mail addresses and URLs for websites.

  12. EPA QUICK REFERENCE GUIDES

    EPA Science Inventory

    EPA Quick Reference Guides are compilations of information on chemical and biological terrorist agents. The information is presented in consistent format and includes agent characteristics, release scenarios, health and safety data, real-time field detection, effect levels, samp...

  13. EERE Peer Review Guide

    SciTech Connect

    2009-01-18

    The primary purpose of this guide is to provide managers and staff guidance in establishing formal in-progress peer review that provides intellectually fair expert evaluation of EERE RD3 and supporting business administration programs, both retrospective and prospective.

  14. The Saturn Educator Guide

    NASA Astrophysics Data System (ADS)

    Morrow, C. A.; Throop, H. B.

    1998-09-01

    NASA's Cassini Mission to Saturn is the most ambitious deep space mission ever. Its 4-year scientific tour of Saturn, its majestic rings, and its 18 presently known moons will reveal new beauty, richness and insights on behalf of all humankind. This presentation introduces the inquiry-based lessons from the innovative Saturn Educator Guide, appropriate for grades 5-8. The Guide is the product of a collaborative venture among teachers, scientists, engineers, and education researchers. The Guide offers opportunities to explore Saturn as a system, and the Cassini robotic spacecraft as an extension of human senses. There are also unique lessons on the history of science, science as a human endeavor, and science in social and personal perspectives. The Guide highlights the interconnections between Saturn and other areas of human endeavor (art, language, history and mythology). This distinctive blend will enable a grander diversity of learners to share and benefit from the excitement of Cassini mission discoveries.

  15. Guided Inquiry Laboratory.

    ERIC Educational Resources Information Center

    Allen, J. B.; And Others

    1986-01-01

    Advocates the use of discovery or guided inquiry experiments for developing critical thinking in problem solving. Provides a stepwise method for creating inquiry experiments and provides an example by comparing the two methods for a freezing point experiment. (JM)

  16. Operator Certification Study Guide.

    ERIC Educational Resources Information Center

    American Water Works Association, Denver, CO.

    This study guide contains typical questions and answers that all levels of water treatment plant operators might expect to find on a certification examination. The manual covers the basic sciences, treatment techniques, testing procedures, and federal legislation. (Author/SB)

  17. AGU Legislative Guide available

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    A guide to help AGU members communicate with legislators and government agency officials is available free of charge from AGU headquarters. The guide is based on the premise that input from the scientific community assists government to make decisions based on the latest factual information available.AGU's Guide to Legislative Information and Contacts was developed by AGU's Committee on Public Affairs and is based largely on a publication of the American Institute of Biological Sciences. The guide briefly outlines the key steps in the legislative process and lists sources of information on legislation. The booklet also provides guidelines for corresponding with legislators a n d for providing scientific testimony to Congress. It also delineates some o f the constraints under which AGU must operate when undertaking legislative activities.

  18. ELECTRONIC PULSE SCALING CIRCUITS

    DOEpatents

    Cooke-Yarborough, E.H.

    1958-11-18

    Electronic pulse scaling circults of the klnd comprlsing a serles of bi- stable elements connected ln sequence, usually in the form of a rlng so as to be cycllcally repetitive at the highest scallng factor, are described. The scaling circuit comprises a ring system of bi-stable elements each arranged on turn-off to cause, a succeeding element of the ring to be turned-on, and one being arranged on turn-off to cause a further element of the ring to be turned-on. In addition, separate means are provided for applying a turn-off pulse to all the elements simultaneously, and for resetting the elements to a starting condition at the end of each cycle.

  19. Computationally intelligent pulsed photoacoustics

    NASA Astrophysics Data System (ADS)

    Lukić, Mladena; Ćojbašić, Žarko; Rabasović, Mihailo D.; Markushev, Dragan D.

    2014-12-01

    In this paper, the application of computational intelligence in pulsed photoacoustics is discussed. Feedforward multilayer perception networks are applied for real-time simultaneous determination of the laser beam spatial profile and vibrational-to-translational relaxation time of the polyatomic molecules in gases. Networks are trained and tested with theoretical data adjusted for a given experimental set-up. Genetic optimization has been used for calculation of the same parameters, fitting the photoacoustic signals with a different number of generations. Observed benefits from the application of computational intelligence in pulsed photoacoustics and advantages over previously developed methods are discussed, such as real-time operation, high precision and the possibility of finding solutions in a wide range of parameters, similar to in experimental conditions. In addition, the applicability for practical uses, such as the real-time in situ measurements of atmospheric pollutants, along with possible further developments of obtained results, is argued.

  20. Laser pulse detector

    DOEpatents

    Mashburn, D.N.; Akerman, M.A.

    1979-08-13

    A laser pulse detector is provided which is small and inexpensive and has the capability of detecting laser light of any wavelength with fast response (less than 5 nanoseconds rise time). The laser beam is focused onto the receiving end of a graphite rod coaxially mounted within a close-fitting conductive, open-end cylindrical housing so that ablation and electric field breakdown of the resulting plasma occurs due to a bias potential applied between the graphite rod and housing. The pulse produced by the breakdown is transmitted through a matched impedance coaxial cable to a recording device. The cable is connected with its central lead to the graphite rod and its outer conductor to the housing.

  1. Laser pulse detector

    DOEpatents

    Mashburn, Douglas N.; Akerman, M. Alfred

    1981-01-01

    A laser pulse detector is provided which is small and inexpensive and has the capability of detecting laser light of any wavelength with fast response (less than 5 nanoseconds rise time). The laser beam is focused onto the receiving end of a graphite rod coaxially mounted within a close-fitting conductive, open-end cylindrical housing so that ablation and electric field breakdown of the resulting plasma occurs due to a bias potential applied between the graphite rod and housing. The pulse produced by the breakdown is transmitted through a matched impedance coaxial cable to a recording device. The cable is connected with its central lead to the graphite rod and its outer conductor to the housing.

  2. Noisy homoclinic pulse dynamics

    NASA Astrophysics Data System (ADS)

    Eaves, T. S.; Balmforth, Neil J.

    2016-04-01

    The effect of stochastic perturbations on nearly homoclinic pulse trains is considered for three model systems: a Duffing oscillator, the Lorenz-like Shimizu-Morioka model, and a co-dimension-three normal form. Using the Duffing model as an example, it is demonstrated that the main effect of noise does not originate from the neighbourhood of the fixed point, as is commonly assumed, but due to the perturbation of the trajectory outside that region. Singular perturbation theory is used to quantify this noise effect and is applied to construct maps of pulse spacing for the Shimizu-Morioka and normal form models. The dynamics of these stochastic maps is then explored to examine how noise influences the sequence of bifurcations that take place adjacent to homoclinic connections in Lorenz-like and Shilnikov-type flows.

  3. CW-pulsed laser

    SciTech Connect

    Wert, J. C.

    1981-09-01

    An apparatus for generating a spatially coherent laser beam having both CW and pulsed modes is disclosed. The modes are generated in differing volumetric regions of a single gain medium excited by a continuous energy pump. The CW portion of the output beam passes from the gain medium through a partially transmissive output coupling. The pulsed modes in the output beam are created in the respective region of the gain medium when transition materials from a selected group are stimulated to undergo an abrupt change between their reflective and transmissive states. Either cavity dumped or Q-switched configurations can be created by selective and patterned location of the transition materials at the ends of the gain medium. Symmetric organization of the volumetric regions within the gain medium allows temporal superposition of the two modes while maintaining spatial distinctiveness within the laser beam generated.

  4. Pulsed electron beam precharger

    SciTech Connect

    Finney, W.C.; Shelton, W.N.

    1989-01-01

    This is the fifth in a series of contracts and grants exploring the advanced particulate pollution control technology of electron beam precipitation. The chief goal of the current contract is to develop a laboratory scale electron beam precharger using a pulsed electric field to the proof-of-concept stage. Contract tasks leading to the achievement of this goal are generally divided up into two categories: tasks required to bring the Electron Beam Precipitator (EBP) test system up to an operational level for the contract work, and tasks concerning the actual experimental and analytical phase of the study. Not unexpectedly, the early portion of the contract duration will be devoted to the commissioning of the EBP and its many subsystems, while the latter portion will devote itself to testing the new pulsed electron beam precharger.

  5. Micro pulse laser radar

    NASA Technical Reports Server (NTRS)

    Spinhirne, James D. (Inventor)

    1993-01-01

    An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited to optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micropulse lider systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

  6. Short pulse neutron generator

    DOEpatents

    Elizondo-Decanini, Juan M.

    2016-08-02

    Short pulse neutron generators are described herein. In a general embodiment, the short pulse neutron generator includes a Blumlein structure. The Blumlein structure includes a first conductive plate, a second conductive plate, a third conductive plate, at least one of an inductor or a resistor, a switch, and a dielectric material. The first conductive plate is positioned relative to the second conductive plate such that a gap separates these plates. A vacuum chamber is positioned in the gap, and an ion source is positioned to emit ions in the vacuum chamber. The third conductive plate is electrically grounded, and the switch is operable to electrically connect and disconnect the second conductive plate and the third conductive plate. The at least one of the resistor or the inductor is coupled to the first conductive plate and the second conductive plate.

  7. Noisy homoclinic pulse dynamics.

    PubMed

    Eaves, T S; Balmforth, Neil J

    2016-04-01

    The effect of stochastic perturbations on nearly homoclinic pulse trains is considered for three model systems: a Duffing oscillator, the Lorenz-like Shimizu-Morioka model, and a co-dimension-three normal form. Using the Duffing model as an example, it is demonstrated that the main effect of noise does not originate from the neighbourhood of the fixed point, as is commonly assumed, but due to the perturbation of the trajectory outside that region. Singular perturbation theory is used to quantify this noise effect and is applied to construct maps of pulse spacing for the Shimizu-Morioka and normal form models. The dynamics of these stochastic maps is then explored to examine how noise influences the sequence of bifurcations that take place adjacent to homoclinic connections in Lorenz-like and Shilnikov-type flows. PMID:27131483

  8. Wind Energy Teachers Guide

    SciTech Connect

    anon.

    2003-01-01

    This guide, created by the American Wind Association, with support from the U.S. Department of Energy, is a learning tool about wind energy targeted toward grades K-12. The guide provides teacher information, ideas for sparking children's and students' interest, suggestions for activities to undertake in and outside the classroom, and research tools for both teachers and students. Also included is an additional resources section.

  9. Security guide for subcontractors

    SciTech Connect

    Adams, R.C.

    1991-01-01

    This security guide of the Department of Energy covers contractor and subcontractor access to DOE and Mound facilities. The topics of the security guide include responsibilities, physical barriers, personnel identification system, personnel and vehicular access controls, classified document control, protecting classified matter in use, storing classified matter repository combinations, violations, security education clearance terminations, security infractions, classified information nondisclosure agreement, personnel security clearances, visitor control, travel to communist-controlled or sensitive countries, shipment security, and surreptitious listening devices.

  10. VOLTTRON: User Guide

    SciTech Connect

    Lutes, Robert G.; Katipamula, Srinivas; Akyol, Bora A.; Tenney, Nathan D.; Haack, Jereme N.; Monson, Kyle E.; Carpenter, Brandon J.

    2014-04-24

    This document is a user guide for the deployment of the Transactional Network platform and agent/application development within the VOLTTRON. The intent of this user guide is to provide a description of the functionality of the Transactional Network Platform. This document describes how to deploy the platform, including installation, use, guidance, and limitations. It also describes how additional features can be added to enhance its current functionality.

  11. Mechanism For Guided Release

    NASA Technical Reports Server (NTRS)

    Kull, Richard A.

    1990-01-01

    Proposed mechanism retains protective shield until no longer needed, then releases shield and guides it away for safe ejection from vehicle (spacecraft, according to original concept). Intended for use with shield like one described in article "Crash-Resistant Shield" (NPO-17616). Mechanism for guided release separates shield from base and from supporting truss on command. Band holding shield on base released by explosive separator.

  12. Energy pulse bonding

    NASA Technical Reports Server (NTRS)

    Smith, G. C.

    1972-01-01

    To eliminate many of the present termination problems a technique called energy pulse bonding (EPB) was developed. The process demonstrated the capability of: (1) joining conductors without prior removal of insulations, (2) joining conductors without danger of brittle intermetallics, (3) increased joint temperature capability, (4) simultaneous formation of several bonds, (5) capability of higher joint density, and (6) a production oriented process. The following metals were successfully bonded in the solid state: copper, beryllium copper, phosphor bronze, aluminum, brass, and Kovar.

  13. International magnetic pulse compression

    SciTech Connect

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12--14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card -- its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  14. Pulsed laser microtomograph

    NASA Astrophysics Data System (ADS)

    Antonov, V. B.; Bonch-Bruevich, A. M.; Vasil'Ev, V. I.; Ionov, L. N.; Nikolaev, S. D.; Starobogatov, I. O.

    1994-12-01

    This paper describes a pulsed laser tomographic apparatus that has been implemented in practice and has a spatial resolution of 2-5 microns in the transverse direction and approximately 70 microns in the probe-radiation propagation direction. Experiments have been performed with model objects. Results have been obtained that confirm the possibility of early diagnosis of skin mycoses that cannot be diagnosed by existing methods.

  15. International magnetic pulse compression

    NASA Astrophysics Data System (ADS)

    Kirbie, H. C.; Newton, M. A.; Siemens, P. D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12-14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card - its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  16. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1989-01-01

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

  17. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  18. Pulse Portraiture: Pulsar timing

    NASA Astrophysics Data System (ADS)

    Pennucci, Timothy T.; Demorest, Paul B.; Ransom, Scott M.

    2016-06-01

    Pulse Portraiture is a wideband pulsar timing code written in python. It uses an extension of the FFTFIT algorithm (Taylor 1992) to simultaneously measure a phase (TOA) and dispersion measure (DM). The code includes a Gaussian-component-based portrait modeling routine. The code uses the python interface to the pulsar data analysis package PSRCHIVE (ascl:1105.014) and also requires the non-linear least-squares minimization package lmfit (ascl:1606.014).

  19. Pulsed gas laser

    DOEpatents

    Anderson, Louis W.; Fitzsimmons, William A.

    1978-01-01

    A pulsed gas laser is constituted by Blumlein circuits wherein space metal plates function both as capacitors and transmission lines coupling high frequency oscillations to a gas filled laser tube. The tube itself is formed by spaced metal side walls which function as connections to the electrodes to provide for a high frequency, high voltage discharge in the tube to cause the gas to lase. Also shown is a spark gap switch having structural features permitting a long life.

  20. STIRAP with XFEL pulses

    NASA Astrophysics Data System (ADS)

    Picon, Antonio; Southworth, Stephen

    2015-05-01

    The development of the laser in the optical-IR regime stimulated completely new schemes for controlling quantum systems by resorting to the coherence of the light-matter interaction. Along this line, it is interesting to explore these schemes or new ones in the x-ray regime, especially with the advent of x-ray free-electron lasers (XFELs) which deliver spatio-temporal coherent pulses in the femtosecond timescale. The new factor in the x-ray regime with respect to the optical regime is the unavoidable creation and ultrafast decay of core-excited states driven by strong electron correlations that one needs to consider. Hence, X-Ray Quantum Optics opens an interesting field in order to explore strongly correlated systems driven by x-ray pulses, and definitely it will play a crucial role in the development of characterization methods for x-ray pulses at XFELs. Here, we propose a theoretical scheme for STIRAP (Stimulated Raman Adiabatic Passage) in Ne gas for the soft x-ray regime. Experimental feasibility will be discussed. This work is funded by the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy, under Contract No. DE-AC02-06CH11357.

  1. Pulsed thermionic converter study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A nuclear electric propulsion concept using a thermionic reactor inductively coupled to a magnetoplasmadynamic accelerator (MPD arc jet) is described, and the results of preliminary analyses are presented. In this system, the MPD thruster operates intermittently at higher voltages and power levels than the thermionic generating unit. A typical thrust pulse from the MPD arc jet is characterized by power levels of 1 to 4 MWe, a duration of 1 msec, and a duty cycle of approximately 20%. The thermionic generating unit operates continuously but with a lower power level of approximately 0.4 MWe. Energy storage between thrust pulses is provided by building up a large current in an inductor using the output of the thermionic converter array. Periodically, the charging current is interrupted, and the energy stored in the magnetic field of the inductor is utilized for a short duration thrust pulse. The results of the preliminary analysis show that a coupling effectiveness of approximately 85 to 90% is feasible for a nominal 400 KWe system with an inductive unit suitable for a flight vehicle.

  2. Emerging Roles of PAR-1 and PAFR in Melanoma Metastasis

    PubMed Central

    Melnikova, Vladislava O.; Villares, Gabriel J.

    2008-01-01

    Melanoma growth, angiogenesis and metastatic progression are strongly promoted by the inflammatory tumor microenvironment due to high levels of cytokine and chemokine secretion by the recruited inflammatory and stromal cells. In addition, platelets and molecular components of procoagulant pathways have been recently emerging as critical players of tumor growth and metastasis. In particular, thrombin, through the activity of its receptor protease-activated receptor-1 (PAR-1), regulates tumor cell adhesion to platelets and endothelial cells, stimulates tumor angiogenesis, and promotes tumor growth and metastasis. Notably, in many tumor types including melanoma, PAR-1 expression directly correlates with their metastatic phenotype and is directly responsible for the expression of interleukin-8, matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor, platelet-derived growth factor, and integrins. Another proinflammatory receptor–ligand pair, platelet-activating factor (PAF) and its receptor (PAFR), have been shown to act as important modulators of tumor cell adhesion to endothelial cells, angiogenesis, tumor growth and metastasis. PAF is a bioactive lipid produced by a variety of cells from membrane glycerophospholipids in the same reaction that releases arachidonic acid, and can be secreted by platelets, inflammatory cells, keratinocytes and endothelial cells. We have demonstrated that in metastatic melanoma cells, PAF stimulates the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and activating transcription factor 1 (ATF-1), which results in overexpression of MMP-2 and membrane type 1-MMP (membrane type 1-MMP). Since only metastatic melanoma cells overexpress CREB/ATF-1, we propose that metastatic melanoma cells are better equipped than their non-metastatic counterparts to respond to PAF within the tumor microenvironment. The evidence supporting the hypothesis that the two G-protein coupled receptors, PAR-1

  3. Emerging roles of PAR-1 and PAFR in melanoma metastasis.

    PubMed

    Melnikova, Vladislava O; Villares, Gabriel J; Bar-Eli, Menashe

    2008-12-01

    Melanoma growth, angiogenesis and metastatic progression are strongly promoted by the inflammatory tumor microenvironment due to high levels of cytokine and chemokine secretion by the recruited inflammatory and stromal cells. In addition, platelets and molecular components of procoagulant pathways have been recently emerging as critical players of tumor growth and metastasis. In particular, thrombin, through the activity of its receptor protease-activated receptor-1 (PAR-1), regulates tumor cell adhesion to platelets and endothelial cells, stimulates tumor angiogenesis, and promotes tumor growth and metastasis. Notably, in many tumor types including melanoma, PAR-1 expression directly correlates with their metastatic phenotype and is directly responsible for the expression of interleukin-8, matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor, platelet-derived growth factor, and integrins. Another proinflammatory receptor-ligand pair, platelet-activating factor (PAF) and its receptor (PAFR), have been shown to act as important modulators of tumor cell adhesion to endothelial cells, angiogenesis, tumor growth and metastasis. PAF is a bioactive lipid produced by a variety of cells from membrane glycerophospholipids in the same reaction that releases arachidonic acid, and can be secreted by platelets, inflammatory cells, keratinocytes and endothelial cells. We have demonstrated that in metastatic melanoma cells, PAF stimulates the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and activating transcription factor 1 (ATF-1), which results in overexpression of MMP-2 and membrane type 1-MMP (membrane type 1-MMP). Since only metastatic melanoma cells overexpress CREB/ATF-1, we propose that metastatic melanoma cells are better equipped than their non-metastatic counterparts to respond to PAF within the tumor microenvironment. The evidence supporting the hypothesis that the two G-protein coupled receptors, PAR-1

  4. Radiological design guide

    SciTech Connect

    Evans, R.A.

    1994-08-16

    The purpose of this design guide is to provide radiological safety requirements, standards, and information necessary for designing facilities that will operate without unacceptable risk to personnel, the public, or the environment as required by the US Department of Energy (DOE). This design guide, together with WHC-CM-4-29, Nuclear Criticality Safety, WHC-CM-4-46, Nonreactor Facility Safety Analysis, and WHC-CM-7-5, Environmental Compliance, covers the radiation safety design requirements at Westinghouse Hanford Company (WHC). This design guide applies to the design of all new facilities. The WHC organization with line responsibility for design shall determine to what extent this design guide shall apply to the modifications to existing facilities. In making this determination, consideration shall include a cost versus benefit study. Specifically, facilities that store, handle, or process radioactive materials will be covered. This design guide replaces WHC-CM-4-9 and is designated a living document. This design guide is intended for design purposes only. Design criteria are different from operational criteria and often more stringent. Criteria that might be acceptable for operations might not be adequate for design.

  5. Control system design guide

    SciTech Connect

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  6. MULTICHANNEL PULSE-HEIGHT ANALYZER

    DOEpatents

    Russell, J.T.; Lefevre, H.W.

    1958-01-21

    This patent deals with electronic computing circuits and more particularly to pulse-height analyzers used for classifying variable amplitude pulses into groups of different amplitudes. The device accomplishes this pulse allocation by by converting the pulses into frequencies corresponding to the amplitudes of the pulses, which frequencies are filtered in channels individually pretuned to a particular frequency and then detected and recorded in the responsive channel. This circuit substantially overcomes the disadvantages of prior annlyzers incorporating discriminators pre-set to respond to certain voltage levels, since small variation in component values is not as critical to satisfactory circuit operation.

  7. A systematic computation scheme of PAR-WIG cruising performance

    NASA Astrophysics Data System (ADS)

    Ando, Shigenori

    1993-08-01

    A systematic computation scheme is presented for PAR-WIG cruising performance, on a FORTRAN program. It is suitable for implementation on PCs. Effects of many parameters on the transportation efficiency are explored. Two concepts are presented in three views and artist impressions. One is a smallest single-crewman vehicle for experiment, sports, or pleasure. The other is a large vehicle for civil transportation. Both have twin hulls, which are quite suitable for installing a 'SMALL-TAIL-WIG' or 'WIG-let' to establish longitudinal attitude stability.

  8. BOREAS TE-12 Incoming PAR Through the Forest Canopy Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-12 (Terrestrial Ecology) team collected photosynthetically active radiation (PAR) data sets in support of its efforts to characterize and interpret information on shoot geometry, leaf optical properties, leaf water potential, and leaf gas exchange. The data were collected at the Southern Study Area-Old Black Spruce (SSA-OBS) site from 04-Jul-1996 to 25-Jul-1996. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  9. Marketing and Society. Study Guide.

    ERIC Educational Resources Information Center

    Welsh, Robert S.; Blake, Rowland S.

    This self-instructional study guide is part of the materials for a college-level programmed course entitled "Marketing and Society." The study guide is intended for use by students in conjunction with a related textbook, a workbook, a review guide, and a series of instructional tape casettes. The study guide contains a brief introductory section…

  10. Electromagnetically Induced Guiding and Superradiant Amplification of Counter-Propagating Lasers in Plasma

    SciTech Connect

    Fisch, N.J.; Shvets, G.

    1998-08-01

    The interaction of counter-propagating laser pulses in a plasma in considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order the plasma period) laser pulse can be nonlinearly focused by a long counter-propagating beam which extends over the entire guiding length. It is also demonstrated that a short (< 1/ omega (sub p)) laser pulse can be superradiantly amplified by a counter-propagating long low-intensity pump while remaining ultra-short. Particle-in-Cell simulations indicate that pump depletion can be as high as 40%. This implies that the long pump is efficiently compressed in time without frequency chirping and pulse stretching, making the superradiant amplification an interesting alternative to the conventional method of producing ultra-intense pulses by the chirped-pulse amplification.

  11. Petawatt pulsed-power accelerator

    DOEpatents

    Stygar, William A.; Cuneo, Michael E.; Headley, Daniel I.; Ives, Harry C.; Ives, legal representative; Berry Cottrell; Leeper, Ramon J.; Mazarakis, Michael G.; Olson, Craig L.; Porter, John L.; Wagoner; Tim C.

    2010-03-16

    A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

  12. Band-selective radiofrequency pulses

    NASA Astrophysics Data System (ADS)

    Geen, Helen; Freeman, Ray

    A theoretical treatment is given of the general problem of designing amplitude-modulated radiofrequency pulses that will excite a specified band of frequencies within a high-resolution NMR spectrum with uniform intensity and phase but with negligible excitation elsewhere. First a trial pulse envelope is defined in terms of a finite Fourier series and its frequency-domain profile calculated through the Bloch equations. The result is compared with the desired target profile to give a multidimensional error surface. The method of simulated annealing is then used to find the global minimum on this surface and the result refined by standard gradient-descent optimization. In this manner, a family of new shaped radio-frequency pulses, known as BURP ( band-selective, uniform response, pure-phase) pulses, has been created. These are of two classes—pulses that excite or invert z magnetization and those that act as general-rotation πr/2 or π pulses irrespective of the initial condition of the nuclear magnetization. It was found convenient to design the latter class as amplitude-modulated time-symmetric pulses. Tables of Fourier coefficients and pulse-shape ordinates are given for practical implementation of BURP pulses, together with the calculated frequency-domain responses and experimental verifications. Examples of the application of band-selective pulses in conventional and multidimensional spectroscopy are given. Pure-phase pulses of this type should also find applications in magnetic resonance imaging where refocusing schemes are undesirable.

  13. Pulsed power packs a punch

    NASA Astrophysics Data System (ADS)

    Weldon, W. F.

    1985-03-01

    Utilities supply electric power routinely in a continuous flow, while in certain cases power must be delivered in short, huge bursts, taking into account applications such as thermonuclear-fusion research, high-energy particle accelerators, lasers, and electromagnetic launchers. For the delivery of this 'pulsed power', it is necessary to collect energy at low power, store it, and release it almost instantaneously. During the last decade, pulsed-power technology has become a recognized engineering discipline. Pulsed-power systems can now deliver gigajoules of energy, megamperes of current, or terawatts of power, while pulse widths range from microseconds to several seconds. Attention is given to capacitors as one of the oldest storage devices for electric energy, inductors, the linking of capacitors and inductors, pulse creation, the use of explosives to generate pulsed power, limitations regarding the effectiveness of batteries, low-cost energy storage provided by flywheels, dc machines, ac machines, and new applications for pulsed power.

  14. Laser beam pulse formatting method

    DOEpatents

    Daly, Thomas P.; Moses, Edward I.; Patterson, Ralph W.; Sawicki, Richard H.

    1994-01-01

    A method for formatting a laser beam pulse (20) using one or more delay loops (10). The delay loops (10) have a partially reflective beam splitter (12) and a plurality of highly reflective mirrors (14) arranged such that the laser beam pulse (20) enters into the delay loop (10) through the beam splitter (12) and circulates therein along a delay loop length (24) defined by the mirrors (14). As the laser beam pulse (20) circulates within the delay loop (10) a portion thereof is emitted upon each completed circuit when the laser beam pulse (20) strikes the beam splitter (12). The laser beam pulse (20) is thereby formatted into a plurality of sub-pulses (50, 52, 54 and 56). The delay loops (10) are used in combination to produce complex waveforms by combining the sub-pulses (50, 52, 54 and 56) using additive waveform synthesis.

  15. Laser beam pulse formatting method

    DOEpatents

    Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

    1994-08-09

    A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

  16. Quarter-wave pulse tube

    NASA Astrophysics Data System (ADS)

    Swift, G. W.; Gardner, D. L.; Backhaus, S. N.

    2011-10-01

    In high-power pulse-tube refrigerators, the pulse tube itself can be very long without too much dissipation of acoustic power on its walls. The pressure amplitude, the volume-flow-rate amplitude, and the time phase between them evolve significantly along a pulse tube that is about a quarter-wavelength long. Proper choice of length and area makes the oscillations at the ambient end of the long pulse tube optimal for driving a second, smaller pulse-tube refrigerator, thereby utilizing the acoustic power that would typically have been dissipated in the first pulse-tube refrigerator's orifice. Experiments show that little heat is carried from the ambient heat exchanger to the cold heat exchanger in such a long pulse tube, even though the oscillations are turbulent and even when the tube is compactly coiled.

  17. Estimating Photosynthetically Available Radiation (PAR) at the Earth's surface from satellite observations

    NASA Technical Reports Server (NTRS)

    Frouin, Robert

    1993-01-01

    Current satellite algorithms to estimate photosynthetically available radiation (PAR) at the earth' s surface are reviewed. PAR is deduced either from an insolation estimate or obtained directly from top-of-atmosphere solar radiances. The characteristics of both approaches are contrasted and typical results are presented. The inaccuracies reported, about 10 percent and 6 percent on daily and monthly time scales, respectively, are useful to model oceanic and terrestrial primary productivity. At those time scales variability due to clouds in the ratio of PAR and insolation is reduced, making it possible to deduce PAR directly from insolation climatologies (satellite or other) that are currently available or being produced. Improvements, however, are needed in conditions of broken cloudiness and over ice/snow. If not addressed properly, calibration/validation issues may prevent quantitative use of the PAR estimates in studies of climatic change. The prospects are good for an accurate, long-term climatology of PAR over the globe.

  18. High-speed pulse-shape generator, pulse multiplexer

    DOEpatents

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  19. Optimal Bichromatic Two-Photon Excitation with Near-Resonant Chirped Pulses

    SciTech Connect

    Serrat, Carles; Biegert, Jens

    2007-12-26

    We investigate a method for creating complete population inversion in a three level system by using bichromatic two-photon coherent excitations with laser pulses, and study the dependence of the optimal population transfer on the chirp of the pulses. We observe that the population inversion does not monotonously decrease with increasing the time-bandwidth product, and that the excitation depends on the sign of the chirp of the individual pulses. Our results, which evidence a worthwhile strategy for coherent population transfer in three level systems, are particularized to the level structure of atomic sodium, with regard to applications in bichromatic mesospheric guide stars.

  20. Observation of Optical Pulse and Material Dynamics on the Femtosecond Time-Scale

    SciTech Connect

    Omenetto, F.; Luce, B.; Siders, C.W.; Taylor, A.J.

    1999-09-13

    The widespread availability of lasers that generate pulses on the femtosecond scale has opened new realms of investigation in the basic and applied sciences, rendering available excitations delivering intensities well in excess of 10{sup 21} W/cm{sup 2}, and furnishing probes capable of resolving molecular relaxation timescales. As a consequence and a necessity, sophisticated techniques to examine the pulse behavior on the femtosecond scale have been developed and are of crucial importance to gain insight on the behavior of physical systems. These techniques will be discussed with specific application to guided pulse propagation and ionization dynamics of noble gases.

  1. Fluoroquinolone Resistance Mutations in the parC, parE, and gyrA Genes of Clinical Isolates of Viridans Group Streptococci

    PubMed Central

    González, Irene; Georgiou, Marios; Alcaide, Fernando; Balas, Delia; Liñares, Josefina; de la Campa, Adela G.

    1998-01-01

    The nucleotide sequences of the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes from seven ciprofloxacin-resistant (Cpr) isolates of viridans group streptococci (two high-level Cpr Streptococcus oralis and five low-level Cpr Streptococcus mitis isolates) were determined and compared with those obtained from susceptible isolates. The nucleotide sequences of the QRDRs of the parE and gyrB genes from the five low-level Cpr S. mitis isolates and from the NCTC 12261 type strain were also analyzed. Four of these low-level Cpr isolates had changes affecting the subunits of DNA topoisomerase IV: three in Ser-79 (to Phe or Ile) of ParC and one in ParE at a position not previously described to be involved in quinolone resistance (Pro-424). One isolate did not show any mutation. The two high-level Cpr S. oralis isolates showed mutations affecting equivalent residue positions of ParC and GyrA, namely, Ser-79 to Phe and Ser-81 to Phe or Tyr, respectively. The parC mutations were able to transform Streptococcus pneumoniae to ciprofloxacin resistance, while the gyrA mutations transformed S. pneumoniae only when mutations in parC were present. These results suggest that DNA topoisomerase IV is a primary target of ciprofloxacin in viridans group streptococci, DNA gyrase being a secondary target. PMID:9797205

  2. PAR2-dependent activation of GSK3β regulates the survival of colon stem/progenitor cells.

    PubMed

    Nasri, Imen; Bonnet, Delphine; Zwarycz, Bailey; d'Aldebert, Emilie; Khou, Sokchea; Mezghani-Jarraya, Raoudha; Quaranta, Muriel; Rolland, Corinne; Bonnart, Chrystelle; Mas, Emmanuel; Ferrand, Audrey; Cenac, Nicolas; Magness, Scott; Van Landeghem, Laurianne; Vergnolle, Nathalie; Racaud-Sultan, Claire

    2016-08-01

    Protease-activated receptors PAR1 and PAR2 play an important role in the control of epithelial cell proliferation and migration. However, the survival of normal and tumor intestinal stem/progenitor cells promoted by proinflammatory mediators may be critical in oncogenesis. The glycogen synthase kinase-3β (GSK3β) pathway is overactivated in colon cancer cells and promotes their survival and drug resistance. We thus aimed to determine PAR1 and PAR2 effects on normal and tumor intestinal stem/progenitor cells and whether they involved GSK3β. First, PAR1 and PAR2 were identified in colon stem/progenitor cells by immunofluorescence. In three-dimensional cultures of murine crypt units or single tumor Caco-2 cells, PAR2 activation decreased numbers and size of normal or cancerous spheroids, and PAR2-deficient spheroids showed increased proliferation, indicating that PAR2 represses proliferation. PAR2-stimulated normal cells were more resistant to stress (serum starvation or spheroid passaging), suggesting prosurvival effects of PAR2 Accordingly, active caspase-3 was strongly increased in PAR2-deficient normal spheroids. PAR2 but not PAR1 triggered GSK3β activation through serine-9 dephosphorylation in normal and tumor cells. The PAR2-triggered GSK3β activation implicates an arrestin/PP2A/GSK3β complex that is dependent on the Rho kinase activity. Loss of PAR2 was associated with high levels of GSK3β nonactive form, strengthening the role of PAR2 in GSK3β activation. GSK3 pharmacological inhibition impaired the survival of PAR2-stimulated spheroids and serum-starved cells. Altogether our data identify PAR2/GSK3β as a novel pathway that plays a critical role in the regulation of stem/progenitor cell survival and proliferation in normal colon crypts and colon cancer. PMID:27313176

  3. Brulure par Foudre. A Propos d’une Observation

    PubMed Central

    Mradmi, W.; Fassi-Fihri, J.; Mehaji, G.; Ezzoubi, M.; Diouri, M.; Bahechar, N.; Boukind, E.H.

    2005-01-01

    Summary Aussi loin que l’on remonte dans la littérature, on retrouve des récits relatant des accidents consécutifs à la fulguration chez l’homme. La foudre était alors associée à la colère des dieux ou à la notion de châtiment. La fulguration correspond à un transfert d’énergie entre un cumulonimbus de charge négative et un objet de charge positive se trouvant au niveau du sol. Les lésions déterminées sont à la fois thermiques et électrothermiques. Bien que l’arrêt cardiorespiratoire soit une cause bien documentée de décès, la plupart des cas rapportés dans la littérature décrivent un éventail très disparate des séquelles qui surviennent suite à cet accident. Les Auteurs rapportent le cas d’un patient atteint par la foudre en insistant particulièrement sur les complications neurologiques qui sont survenues en cours d’évolution. Se basant sur cette observation et sur une revue de la littérature, les Auteurs soulignent que le pronostic des patients atteints par la foudre est plus favorable que généralement rapporté. PMID:21990993

  4. The polarity protein Par3 regulates APP trafficking and processing through the endocytic adaptor protein Numb.

    PubMed

    Sun, Miao; Asghar, Suwaiba Z; Zhang, Huaye

    2016-09-01

    The processing of amyloid precursor protein (APP) into β-amyloid peptide (Aβ) is a key step in the pathogenesis of Alzheimer's disease (AD), and trafficking dysregulations of APP and its secretases contribute significantly to altered APP processing. Here we show that the cell polarity protein Par3 plays an important role in APP processing and trafficking. We found that the expression of full length Par3 is significantly decreased in AD patients. Overexpression of Par3 promotes non-amyloidogenic APP processing, while depletion of Par3 induces intracellular accumulation of Aβ. We further show that Par3 functions by regulating APP trafficking. Loss of Par3 decreases surface expression of APP by targeting APP to the late endosome/lysosome pathway. Finally, we show that the effects of Par3 are mediated through the endocytic adaptor protein Numb, and Par3 functions by interfering with the interaction between Numb and APP. Together, our studies show a novel role for Par3 in regulating APP processing and trafficking. PMID:27072891

  5. Coiled transmission line pulse generators

    DOEpatents

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  6. Microwave and Pulsed Power

    SciTech Connect

    Freytag, E.K.

    1993-03-01

    The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

  7. Single electron response of the scintillator-light guide-photomultiplier detector.

    PubMed

    Novák, L; Müllerová, I

    2009-01-01

    The time response of a scintillator-light guide-photomultiplier combination was measured with a time-constant of 3 ns. Single detected electrons were recognizable at the output of the photomultiplier. The distribution of the number of photoelectrons produced by one detected electron and the pulse-height distribution of the photomultiplier output pulses were analysed. Statistical noise computed from these distributions was compared with the noise produced by the dark current of the photomultiplier. PMID:19196414

  8. Generation of Phase-Locked Pulses from a Seeded Free-Electron Laser.

    PubMed

    Gauthier, David; Ribič, Primož Rebernik; De Ninno, Giovanni; Allaria, Enrico; Cinquegrana, Paolo; Danailov, Miltcho Bojanov; Demidovich, Alexander; Ferrari, Eugenio; Giannessi, Luca

    2016-01-15

    In a coherent control experiment, light pulses are used to guide the real-time evolution of a quantum system. This requires the coherence and the control of the pulses' electric-field carrier waves. In this work, we use frequency-domain interferometry to demonstrate the mutual coherence of time-delayed pulses generated by an extreme ultraviolet seeded free-electron laser. Furthermore, we use the driving seed laser to lock and precisely control the relative phase between the two free-electron laser pulses. This new capability opens the way to a multitude of coherent control experiments, which will take advantage of the high intensity, short wavelength, and short duration of the pulses generated by seeded free-electron lasers. PMID:26824544

  9. Ultrashort pulsed neutron source.

    PubMed

    Pomerantz, I; McCary, E; Meadows, A R; Arefiev, A; Bernstein, A C; Chester, C; Cortez, J; Donovan, M E; Dyer, G; Gaul, E W; Hamilton, D; Kuk, D; Lestrade, A C; Wang, C; Ditmire, T; Hegelich, B M

    2014-10-31

    We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50  ps) and high peak flux (>10(18)  n/cm(2)/s), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3  μm) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory. PMID:25396373

  10. Ultrashort Pulsed Neutron Source

    NASA Astrophysics Data System (ADS)

    Pomerantz, I.; McCary, E.; Meadows, A. R.; Arefiev, A.; Bernstein, A. C.; Chester, C.; Cortez, J.; Donovan, M. E.; Dyer, G.; Gaul, E. W.; Hamilton, D.; Kuk, D.; Lestrade, A. C.; Wang, C.; Ditmire, T.; Hegelich, B. M.

    2014-10-01

    We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50 ps ) and high peak flux (>1018 n /cm2/s ), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3 μ m ) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory.

  11. Pulsed quantum optomechanics

    PubMed Central

    Vanner, M. R.; Pikovski, I.; Cole, G. D.; Kim, M. S.; Brukner, Č.; Hammerer, K.; Milburn, G. J.; Aspelmeyer, M.

    2011-01-01

    Studying mechanical resonators via radiation pressure offers a rich avenue for the exploration of quantum mechanical behavior in a macroscopic regime. However, quantum state preparation and especially quantum state reconstruction of mechanical oscillators remains a significant challenge. Here we propose a scheme to realize quantum state tomography, squeezing, and state purification of a mechanical resonator using short optical pulses. The scheme presented allows observation of mechanical quantum features despite preparation from a thermal state and is shown to be experimentally feasible using optical microcavities. Our framework thus provides a promising means to explore the quantum nature of massive mechanical oscillators and can be applied to other systems such as trapped ions. PMID:21900608

  12. Green Light Pulse Oximeter

    DOEpatents

    Scharf, John Edward

    1998-11-03

    A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

  13. Pulsed Long Arc Welding

    NASA Astrophysics Data System (ADS)

    Krampit, N. Yu

    2016-04-01

    The paper presents a method and an appliance for pulsed arc welding. The method supports dosage of energy required for melting each bead of electrode metal starting from the detachment of a bead. The appliance including a sensor to register bead detachment shows this moment due to the voltage burst in the arc space. Transferred beads of electrode metal are of similar size because of the dosage of energy used for melting each bead, as the consequence, the process is more stable and starting conditions to transfer electrode metal are similar, as the result, a produced weld is improved.

  14. Pulsed electron beam precharger

    NASA Astrophysics Data System (ADS)

    Finney, W. C.

    A short review of electron beam particle precharging using a pulsed electric field is presented. The design and installation is detailed of a remote focusing gear train which will allow much greater control over the particle charge measurement capability of the charge vs. radius apparatus. Progress on the electrical shielding of the rotating spark gap power supply using a large Faraday cage is described. Efforts to prevent RFI interference from adversely affecting the Climet particle counter and the MicroMac current measurement device using a variety of techniques are also presented. The basic effort is to optimize the removal efficiency for fly ash particles.

  15. PULSE SYNTHESIZING GENERATOR

    DOEpatents

    Kerns, Q.A.

    1963-08-01

    >An electronlc circuit for synthesizing electrical current pulses having very fast rise times includes several sinewave generators tuned to progressively higher harmonic frequencies with signal amplitudes and phases selectable according to the Fourier series of the waveform that is to be synthesized. Phase control is provided by periodically triggering the generators at precisely controlled times. The outputs of the generators are combined in a coaxial transmission line. Any frequency-dependent delays that occur in the transmission line can be readily compensated for so that the desired signal wave shape is obtained at the output of the line. (AEC)

  16. Pulsed differential pumping system

    SciTech Connect

    Antipov, G.N.; Bagautdinov, F.A.; Rybalov, S.V.

    1985-06-01

    A pulsed differential pumping system is described for extracting an electron beam from a shaping region at a pressure of 10/sup -5/ torr into a volume with a pressure of 10-100 torr. A fast valve is used with appropriate geometrical parameters to reduce the length of the outlet channel considerable while increasing its diameter. Test results are given. The pumping system has two sections which communicate one with the other and with the volume at the elevated pressure which is produced by gasdynamic nozzles.

  17. Pulsed Plasma Thruster Technology

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The continuing emphasis on reducing costs and downsizing spacecraft is forcing increased emphasis on reducing the subsystem mass and integration costs. For many commercial, scientific, and Department of Defense space missions, onboard propulsion is either the predominant spacecraft mass or it limits the spacecraft lifetime. Electromagnetic-pulsed-plasma thrusters (PPT's) offer the combined benefits of extremely low average electric power requirements (1 to 150 W), high specific impulse (approx. 1000 sec), and system simplicity derived from the use of an inert solid propellant. Potential applications range from orbit insertion and maintenance of small satellites to attitude control for large geostationary communications satellites.

  18. Pulse front tilt measurement of femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Dimitrov, Nikolay; Stoyanov, Lyubomir; Stefanov, Ivan; Dreischuh, Alexander; Hansinger, Peter; Paulus, Gerhard G.

    2016-07-01

    In this work we report experimental investigations of an intentionally introduced pulse front tilt on femtosecond laser pulses by using an inverted field correlator/interferometer. A reliable criterion for the precision in aligning (in principle) dispersionless systems for manipulating ultrashort pulses is developed, specifically including cases when the pulse front tilt is a result of a desired spatio-temporal coupling. The results obtained using two low-dispersion diffraction gratings are in good qualitative agreement with the data from a previously developed analytical model and from an independent interferometric measurement.

  19. Common variants in the human platelet PAR4 thrombin receptor alter platelet function and differ by race

    PubMed Central

    Edelstein, Leonard C.; Simon, Lukas M.; Lindsay, Cory R.; Kong, Xianguo; Teruel-Montoya, Raúl; Tourdot, Benjamin E.; Chen, Edward S.; Ma, Lin; Coughlin, Shaun; Nieman, Marvin; Holinstat, Michael; Shaw, Chad A.

    2014-01-01

    Human platelets express 2 thrombin receptors: protease-activated receptor (PAR)-1 and PAR4. Recently, we reported 3.7-fold increased PAR4-mediated aggregation kinetics in platelets from black subjects compared with white subjects. We now show that platelets from blacks (n = 70) express 14% more PAR4 protein than those from whites (n = 84), but this difference is not associated with platelet PAR4 function. Quantitative trait locus analysis identified 3 common single nucleotide polymorphisms in the PAR4 gene (F2RL3) associated with PAR4-induced platelet aggregation. Among these single nucleotide polymorphisms, rs773902 determines whether residue 120 in transmembrane domain 2 is an alanine (Ala) or threonine (Thr). Compared with the Ala120 variant, Thr120 was more common in black subjects than in white subjects (63% vs 19%), was associated with higher PAR4-induced human platelet aggregation and Ca2+ flux, and generated greater inositol 1,4,5-triphosphate in transfected cells. A second, less frequent F2RL3 variant, Phe296Val, was only observed in blacks and abolished the enhanced PAR4-induced platelet aggregation and 1,4,5-triphosphate generation associated with PAR4-Thr120. PAR4 genotype did not affect vorapaxar inhibition of platelet PAR1 function, but a strong pharmacogenetic effect was observed with the PAR4-specific antagonist YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole]. These findings may have an important pharmacogenetic effect on the development of new PAR antagonists. PMID:25293779

  20. Optically guided controlled release from liposomes with tunable plasmonic nanobubbles.

    PubMed

    Anderson, Lindsey J E; Hansen, Eric; Lukianova-Hleb, Ekaterina Y; Hafner, Jason H; Lapotko, Dmitri O

    2010-06-01

    A new method of optically guided controlled release was experimentally evaluated with liposomes containing a molecular load and gold nanoparticles (NPs). NPs were exposed to short laser pulses to induce transient vapor bubbles around the NPs, plasmonic nanobubbles, in order to disrupt the liposome and eject its molecular contents. The release efficacy was tuned by varying the lifetime and size of the nanobubble with the fluence of the laser pulse. Optical scattering by nanobubbles correlated to the molecular release and was used to guide the release. The release of two fluorescent proteins from individual liposomes has been directly monitored by fluorescence microscopy, while the generation of the plasmonic nanobubbles was imaged and measured with optical scattering techniques. Plasmonic nanobubble-induced release was found to be a mechanical, nonthermal process that requires a single laser pulse and ejects the liposome contents within a millisecond timescale without damage to the molecular cargo and that can be controlled through the fluence of laser pulse. PMID:20156498

  1. Optically Guided Controlled Release from Liposomes With Tunable Plasmonic Nanobubbles

    PubMed Central

    Anderson, Lindsey; Hansen, Eric; Lukianova-Hleb, Ekaterina Y.; Hafner, Jason H.; Lapotko, Dmitri O.

    2010-01-01

    A new method of optically guided controlled release was experimentally evaluated with liposomes containing a molecular load and gold nanoparticles (NPs). NPs were exposed to short laser pulses to induce transient vapor bubbles around the NPs, plasmonic nanobubbles, in order to disrupt the liposome and eject its molecular contents. The release efficacy was tuned by varying the lifetime and size of the nanobubble with the fluence of the laser pulse. Optical scattering by nanobubbles correlated to the molecular release and was used to guide the release. The release of two fluorescent proteins from individual liposomes has been directly monitored by fluorescence microscopy, while the generation of the plasmonic nanobubbles was imaged and measured with optical scattering techniques. Plasmonic nanobubble-induced release was found to be a mechanical, nonthermal process that requires a single laser pulse and ejects of the liposome contents within a millisecond timescale without damage to the molecular cargo and that can be controlled through the fluence of laser pulse. PMID:20156498

  2. Materials Performance buyers guide

    SciTech Connect

    1996-11-01

    The MP Buyers Guide is an exclusive directory of manufacturers, suppliers, and consultants providing products and services for the prevention and control of corrosion. The Guide is divided into three primary directories: Company Directory, Product Directory, and Trade Name Directory. The Guide also contains a NACE Resource Directory. The index of products and services provides an extensive index of manufacturers, suppliers, and consultants, listed according to specific product categories. The index of suppliers, manufacturers, and consultants contains a detailed alphabetical list of more than 900 manufacturers, suppliers, and consultants providing products and services for corrosion prevention and control. Included are each company`s name, address, contact name, phone number, fax number, email address, branch offices, and a brief description of their products and services. The index of product names is an alphabetical listing of product trade names cross-referenced to the manufacturer, supplier, or consultant.

  3. TE_01 High Power Disk Loaded Guide Load

    SciTech Connect

    Farkas, Z.D.; /SLAC

    2005-06-01

    A method to design a matching section from a smooth guide to a disk-loaded guide, using a variation of broadband matching, [1, 2] is described. Using this method, we show how to design high power loads, attenuators and filters. The load consists of a disk-loaded coaxial guide operating in the TE{sub 01}-mode. We use this mode because it has no electric field terminating on a conductor, has no axial currents, and has no current at the cylinder-disk interface. A high power load design that has -35 dB reflection and a 200 MHz, -20 dB bandwidth, is presented. It is expected that it will carry the 600 MW output peak power of the pulse compression network. We use coaxial geometry and stainless steel material to increase the attenuation per cell.

  4. Dynamics of high power and long pulse laser propagation and its control in underdense plasmas

    NASA Astrophysics Data System (ADS)

    Nakatsutsumi, M.; Fuchs, J.; Antici, P.; Audebert, P.; Bourgeois, N.; Grech, M.; Kodama, R.; Lin, T.; Marqués, J. R.; Riazuelo, G.; Romagnani, L.; Tikhonchuk, V.

    2006-10-01

    The study of intense laser pulse propagation through long underdense plasmas is of crucial importance for inertial confinement fusion (ICF). We have performed a systematic study of long pulse beams (τL=400ps,I=10^10˜10^12Wcm-2) propagating through the underdense plasmas (ne=10^19˜10^20cm-3), by controlling two filaments created from the pulses with variable delay and intensity ratio. These experiments have been performed at the LULI laser facility. The results show that the earlier pulse affects the propagation characteristics of the later pulse. The 2D time-resolved sampling camera provides the ability to examine the possibility of enhanced propagation, collimation, and guiding of a trailing pulse induced by an earlier pulse. These facts are of interest for ICF and other applications. In particular, this study opens perspectives, through shaping the pulses temporally, for the control of propagation of long pulses in the low density plasmas that are present within ICF hohlraums.

  5. Pulsed Terahertz Signal Reconstruction

    NASA Astrophysics Data System (ADS)

    Fletcher, J. R.; Swift, G. P.; Dai, DeChang; Chamberlain, J. M.; Upadhya, P. C.

    2007-12-01

    A procedure is outlined which can be used to determine the response of an experimental sample to a single, simple broadband frequency pulse in terahertz frequency time domain spectroscopy (TDS). The advantage that accrues from this approach is that oscillations and spurious signals (arising from a variety of sources in the TDS system or from ambient water vapor) can be suppressed. In consequence, small signals (arising from the interaction of the radiation with the sample) can be more readily observed in the presence of noise. Procedures for choosing key parameters and methods for eliminating further artifacts are described. In particular, the use of input functions which are based on the binomial distribution is described. These binomial functions are used to unscramble the sample response to a simple pulse: they have sufficient flexibility to allow for variations in the spectra of different terahertz sources, some of which have low frequency as well as high frequency cutoffs. The signal processing procedure is validated by simple reflection and transmission experiments using a gap between polytetrafluoroethylene (PTFE) plates to mimic a void within a larger material. It is shown that a resolution of 100μm is easily achievable in reflection geometry after signal processing.

  6. Compensated pulsed alternator

    DOEpatents

    Weldon, William F.; Driga, Mircea D.; Woodson, Herbert H.

    1980-01-01

    This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak outout. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit.

  7. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  8. Pulsed Plasma Thruster Contamination

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Arrington, Lynn A.; Pencil, Eric J.; Carter, Justin; Heminger, Jason; Gatsonis, Nicolas

    1996-01-01

    Pulsed Plasma Thrusters (PPT's) are currently baselined for the Air Force Mightysat II.1 flight in 1999 and are under consideration for a number of other missions for primary propulsion, precision positioning, and attitude control functions. In this work, PPT plumes were characterized to assess their contamination characteristics. Diagnostics included planar and cylindrical Langmuir probes and a large number of collimated quartz contamination sensors. Measurements were made using a LES 8/9 flight PPT at 0.24, 0.39, 0.55, and 1.2 m from the thruster, as well as in the backflow region behind the thruster. Plasma measurements revealed a peak centerline ion density and velocity of approx. 6 x 10(exp 12) cm(exp -3) and 42,000 m/s, respectively. Optical transmittance measurements of the quartz sensors after 2 x 10(exp 5) pulses showed a rapid decrease in plume contamination with increasing angle from the plume axis, with a barely measurable transmittance decrease in the ultraviolet at 90 deg. No change in optical properties was detected for sensors in the backflow region.

  9. Heat driven pulse pump

    NASA Technical Reports Server (NTRS)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  10. Bipolar pulse forming line

    DOEpatents

    Rhodes, Mark A.

    2008-10-21

    A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

  11. Seismic Safety Guide

    SciTech Connect

    Eagling, D.G.

    1983-09-01

    This guide provides managers with practical guidelines for administering a comprehensive earthquake safety program. The Guide is comprehensive with respect to earthquakes in that it covers the most important aspects of natural hazards, site planning, evaluation and rehabilitation of existing buildings, design of new facilities, operational safety, emergency planning, special considerations related to shielding blocks, non-structural elements, lifelines, fire protection and emergency facilities. Management of risk and liabilities is also covered. Nuclear facilities per se are not dealt with specifically. The principles covered also apply generally to nuclear facilities but the design and construction of such structures are subject to special regulations and legal controls.

  12. Emergency Management Guide

    SciTech Connect

    Not Available

    1994-09-01

    This Emergency Management Guide provides guidance for the implementation of the requirements of the Department of Energy (DOE) Emergency Management System (EMS). The DOE EMS is established by DOE 5500.1B, EMERGENCY DEPARTMENT SYSTEM. The provisions of this guide specify neither policy nor responsibilities. It provides an acceptable approach to emergency planning activities at DOE facilities and sites. Other approaches may be used provided that they are approved by the cognizant Program Secretarial Officer (PSO), with the concurrence of the Director of Emergency Operations (DEO).

  13. Synthetic guide star generation

    DOEpatents

    Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  14. Synthetic guide star generation

    DOEpatents

    Payne, Stephen A.; Page, Ralph H.; Ebbers, Christopher A.; Beach, Raymond J.

    2004-03-09

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  15. Manifold tool guide

    DOEpatents

    Djordjevic, Aleksandar

    1983-12-27

    A tool guide that makes possible the insertion of cleaning and/or inspection tools into a manifold pipe that will dislocate and extract the accumulated sediment in such manifold pipes. The tool guide basically comprises a right angled tube (or other angled tube as required) which can be inserted in a large tube and locked into a radially extending cross pipe by adjustable spacer rods and a spring-loaded cone, whereby appropriate cleaning tools can be inserted into to cross pipe for cleaning, inspection, etc.

  16. Manifold tool guide

    DOEpatents

    Djordjevic, A.

    1983-12-27

    A tool guide is described that makes possible the insertion of cleaning and/or inspection tools into a manifold pipe that will dislocate and extract the accumulated sediment in such manifold pipes. The tool guide basically comprises a right angled tube (or other angled tube as required) which can be inserted in a large tube and locked into a radially extending cross pipe by adjustable spacer rods and a spring-loaded cone, whereby appropriate cleaning tools can be inserted into the cross pipe for cleaning, inspection, etc. 3 figs.

  17. Manifold tool guide

    DOEpatents

    Djordjevic, A.

    1982-07-08

    A tool guide that makes possible the insertion of cleaning and/or inspection tools into a manifold pipe that will dislocate and extract the accumulated sediment in such manifold pipes. The tool guide basically comprises a right angled tube (or other angled tube as required) which can be inserted in a large tube and locked into a radially extending cross pipe by adjustable spacer rods and a spring-loaded cone, whereby appropriate cleaning tools can be inserted into to cross pipe for cleaning, inspection, etc.

  18. Pulsed atmospheric fluidized bed combustion

    SciTech Connect

    Not Available

    1992-05-01

    During this first quarter, a lab-scale water-cooled pulse combustor was designed, fabricated, and integrated with old pilot-scale PAFBC test systems. Characterization tests on this pulse combustor firing different kinds of fuel -- natural gas, pulverized coal and fine coal -- were conducted (without fluidized bed operation) for the purpose of finalizing PAFBC full-scale design. Steady-state tests were performed. Heat transfer performance and combustion efficiency of a coal-fired pulse combustor were evaluated.

  19. Low-noise pulse conditioner

    DOEpatents

    Bird, David A.

    1983-01-01

    A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits.

  20. The Practice of Pulse Processing

    NASA Astrophysics Data System (ADS)

    Fowler, J. W.; Alpert, B. K.; Doriese, W. B.; Joe, Y.-I.; O'Neil, G. C.; Ullom, J. N.; Swetz, D. S.

    2015-12-01

    The analysis of data from X-ray microcalorimeters requires great care; their excellent intrinsic energy resolution cannot usually be achieved in practice without a statistically near-optimal pulse analysis and corrections for important systematic errors. We describe the essential parts of a pulse-analysis pipeline for data from X-ray microcalorimeters, including steps taken to reduce systematic gain variation and the unwelcome dependence of filtered pulse heights on the exact pulse-arrival time. We find these steps collectively to be essential tools for getting the best results from a microcalorimeter-based X-ray spectrometer.