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Sample records for polarization control david

  1. NOAA Ship David Starr Jordan Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship David Starr Jordan Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic...

  2. Nuclear reactivity control using laser induced polarization

    International Nuclear Information System (INIS)

    Bowman, C.D.

    1990-01-01

    This patent describes a control element for reactivity control of a fission source provides an atomic density of 3 He in a control volume which is effective to control criticality as the 3 He is spin-polarized. Spin-polarization of the 3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the 3 He for spin-polarizing the 3 He. An alkali-metal vapor may be included with the 3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with 3 He to spin-polarize the 3 He atoms

  3. Basic design of beamline and polarization control

    International Nuclear Information System (INIS)

    Watanabe, M.

    2006-01-01

    The basic concept of synchrotron radiation beamlines for' vacuum ultraviolet and X-ray experiments has been introduced to beginning users and designers of beamlines. The beamline defined here is composed of a front end, pre-mirrors, and a monochromator with refocusing mirrors, which are connected by beam pipes, providing monochromatic light for the experiments. Firstly, time characteristics of the synchrotron radiation are briefly reviewed. Secondly, the basic technology is introduced as the fundamental knowledge required to both users and designers. The topics are photoabsorption by air and solids, front ends and beam pipes, mirrors, monochromators, and filters. Thirdly, the design consideration is described mainly for the designers. The topics are design principle, principle of ray tracing, optical machinery and control, and vacuum. Fourthly, polarization control is considered. The topics are polarizers, polarization diagnosis of beamline, and circularly-polarized light generation. Finally, a brief summary is given introducing some references for further knowledge of the user's and the designers. (authors)

  4. Polarized fuel for controlled thermonuclear fusion

    Science.gov (United States)

    Bartalucci, Sergio

    2017-07-01

    The use of polarized nuclei as a fuel for thermonuclear fusion reactors was suggested more than 30 years ago, providing evidence for a significant increase of the total cross section. In particular, an enhancement factor close to 1.5 is expected in the energy range below 100 keV for the dominant nuclear fusion reactions 2H + 3H → 4He + n + 17.58 MeV and 2H + 3He → 4He + p + 18.34 MeV. Furthermore, the use of polarized fuel allows one to control the ejectile trajectories, via an enhancement in the forward-backward cross section asymmetry due to polarization. This allows some control on the energy transfer from the plasma to the reactor wall or helps concentrate the neutron flux to defined wall areas. Nevertheless, this idea was received with skepticism by the relevant scientific community, due to some uncertainty in the physics of the process, the low efficiency in the production of polarized beams for injection into plasma and the apparent difficulty of preserving the ion polarization for a time long compared with nuclear burning time. But more recently, as a consequence of significant progress in the field of atomic beam sources and polarized targets, the interest in this matter has been refreshed for both inertially and magnetically confined plasmas. The possibility of implementing nuclear polarization in present and future fusion reactors is discussed in this paper. In particular, the interaction between polarized ions and magnetic fields, both static and RF, which are typically used in a Tokamak for plasma heating via ion cyclotron resonance (ICRH), is considered. Also, experimental issues for practically performing a feasibility test on a real fusion reactors are illustrated.

  5. Polarization Shaping for Control of Nonlinear Propagation.

    Science.gov (United States)

    Bouchard, Frédéric; Larocque, Hugo; Yao, Alison M; Travis, Christopher; De Leon, Israel; Rubano, Andrea; Karimi, Ebrahim; Oppo, Gian-Luca; Boyd, Robert W

    2016-12-02

    We study the nonlinear optical propagation of two different classes of light beams with space-varying polarization-radially symmetric vector beams and Poincaré beams with lemon and star topologies-in a rubidium vapor cell. Unlike Laguerre-Gauss and other types of beams that quickly experience instabilities, we observe that their propagation is not marked by beam breakup while still exhibiting traits such as nonlinear confinement and self-focusing. Our results suggest that, by tailoring the spatial structure of the polarization, the effects of nonlinear propagation can be effectively controlled. These findings provide a novel approach to transport high-power light beams in nonlinear media with controllable distortions to their spatial structure and polarization properties.

  6. Polarization controlled UV writing of bragg gratings

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Plougmann, Nikolai; Deyerl, Hans-Jürgen

    2002-01-01

    In conclusion the polarization control method is superior to any double scan method since it allows much more flexible apodization and inclusion of phase shifts, and since only one exposure is required. In many cases the method performs just as well as the most sophisticated phase mask jitter met...

  7. David Asbury (1950-2015)

    CERN Multimedia

    2015-01-01

    It was with great sadness that we learned that David Asbury passed away in his sleep last week.   David joined CERN in 1984 after having worked for some years at RAL in the UK. He was a skilled programmer and systems engineer, and much appreciated by both users and colleagues at CERN. His contributions to IT services include the IBM mainframe workhorse CERN VM, the backup tape service and in recent years the version control services, until his well-deserved retirement at the end of March this year. We will all remember David for his friendly and helpful manners, and as a warm person who was always caring for others, particularly newcomers. David was also a passionate musician and active tennis player. He will be greatly missed by his colleagues. A memorial service took place at 11 a.m. on Monday, 14 December 2015 at the Auditoire Calvin next to the Cathedral in Geneva. His colleagues and friends

  8. Polarization Shaping for Control of Nonlinear Propagation

    Science.gov (United States)

    Bouchard, Frédéric; Larocque, Hugo; Yao, Alison M.; Travis, Christopher; De Leon, Israel; Rubano, Andrea; Karimi, Ebrahim; Oppo, Gian-Luca; Boyd, Robert W.

    2016-12-01

    We study the nonlinear optical propagation of two different classes of light beams with space-varying polarization—radially symmetric vector beams and Poincaré beams with lemon and star topologies—in a rubidium vapor cell. Unlike Laguerre-Gauss and other types of beams that quickly experience instabilities, we observe that their propagation is not marked by beam breakup while still exhibiting traits such as nonlinear confinement and self-focusing. Our results suggest that, by tailoring the spatial structure of the polarization, the effects of nonlinear propagation can be effectively controlled. These findings provide a novel approach to transport high-power light beams in nonlinear media with controllable distortions to their spatial structure and polarization properties.

  9. Here to stay. An interview with Dr. David Satcher, Director, U.S. Centers for Disease Control and Prevention.

    Science.gov (United States)

    Stilkind, J

    1996-11-01

    This paper presents an interview with Dr. David Satcher of the US Centers for Disease Control and Prevention (CDC) on the issue of infectious and chronic diseases. The problem of new and reemerging infectious diseases around the world, particularly in developing countries, is discussed. While drug resistant malaria and sporadic outbreaks of Ebola in Africa have alarmed health programs, AIDS is the major emerging infectious disease throughout the world. Microorganisms have a way of surviving: they mutate, they adapt, and they emerge. The CDC¿s major partner in the global response to emerging infections is WHO. The CDC has learned lessons from its experience with AIDS and Ebola virus events. A system of domestic surveillance and global prevention should be developed. Poverty, hunger and malnutrition may contribute to the rise of chronic diseases in developing countries. The introduction of richer diets higher in cholesterol in combination with a sedentary lifestyle also will also lead to more chronic diseases among people in developing countries. In the future, smoking will have a greater impact on mortality than will any other factor in these countries. Infectious diseases are much less predictable. Drug resistant microorganisms and urbanization counterbalance the development of vaccines. The U.S. health care system wrongly prioritizes tertiary care while spending only 1% of its health budget on the prevention of diseases. Dr. Satcher would like to see the implementation of programs dealing with human behavior, sanitation, immunization and health education as preventive measures.

  10. Computer control of the SMC polarized target

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, J.M. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee]|[CERN, CH-1211 Geneve 23 (Switzerland); Azoulay, R. [CEA, DAPNIA/SIG, CE Saclay, 91191 Gif-sur-Yvette (France); Berglund, P. [Low Temperature Laboratory, Helsinki University of Technology, SF-02150 Espoo (Finland); Dulya, C. [University of California, Department of Physics, Los Angeles, 90024 CA (United States); Gournay, J.F. [CEA, DAPNIA/SIG, CE Saclay, 91191 Gif-sur-Yvette (France); Hayashi, N. [Nagoya University, Department of Physics, Furo-Cho, Chikusa-Ku, 464 Nagoya (Japan); Kyynaeraeinen, J. [CERN, CH-1211 Geneve 23 (Switzerland); Magnon, A. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee; Matichard, G. [CEA, DAPNIA/SIG, CE Saclay, 91191 Gif-sur-Yvette (France); Niinikoski, T.O. [CERN, CH-1211 Geneve 23 (Switzerland); Trentalange, S. [University of California, Department of Physics, Los Angeles, 90024 CA (United States)

    1995-03-01

    The SMC polarized target is controlled through VME crates driven by CPUs working under the VxWorks operating system. The CPUs are connected to a SUN workstation which provides the user interface due to a graphical package named SL-GMS. This results in user friendliness, high modularity and flexibility. The system allows the control of: (1) the superconductive solenoid and the transverse dipole: control of the power supplies; automatic reversal of the spin direction by field rotation; acquisition, display and storage of the electric and cryogenic parameters; generation of alarms; and (2) the dilution refrigerator: evaporator level control; acquisition, display and storage of {approx}100 cryogenic parameters; and generation of alarms. ((orig.))

  11. Hello, David! / Vladlen Livshits

    Index Scriptorium Estoniae

    Livshits, Vladlen

    2005-01-01

    Autori kohtumisest silmapaistva ameerika ajakirjaniku ja kirjaniku David Shipleriga Kohtla-Järvel 1978. aastal, ameerika matemaatiku Benoit Mandelbroti fraktaalse geomeetria teooriast, Lea Livshitsi maalidest

  12. Process control system using polarizing interferometer

    Science.gov (United States)

    Schultz, T.J.; Kotidis, P.A.; Woodroffe, J.A.; Rostler, P.S.

    1994-02-15

    A system for nondestructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading. 38 figures.

  13. Process control system using polarizing interferometer

    Science.gov (United States)

    Schultz, Thomas J.; Kotidis, Petros A.; Woodroffe, Jaime A.; Rostler, Peter S.

    1994-01-01

    A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading.

  14. Controlling vortex chirality and polarity by geometry in magnetic nanodots

    OpenAIRE

    Agramunt Puig, Sebastià

    2014-01-01

    The independent control of both vortex chirality and polarity is a significant challenge in magnetic devices based on nano-sized magnetic vortex structures. By micromagnetic simulations here, we show that in soft ferromagnetic nanodots with an adequate modulated thickness, the desired combination of chirality and polarity can be achieved just by changing the direction of the in-plane applied magnetic field. Despite the complex behavior, the vortex chirality and polarity control can be summari...

  15. Polarization preservation and control in a figure-8 ring

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kondratenko, A. M. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Kondratenko, M. A. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Filatov, Yuri [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058

    2016-02-01

    We present a complete scheme for managing the polarization of ion beams in Jefferson Lab's proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider's experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design are summarized.

  16. Compact electrically controlled broadband liquid crystal photonic bandgap fiber polarizer

    DEFF Research Database (Denmark)

    Wei, Lei; Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard

    2009-01-01

    An electrically controlled liquid crystal photonic-bandgap fiber polarizer is experimentally demonstrated. A maximum 21.3dB electrically tunable polarization extinction ratio is achieved with 45° rotatable transmission axis as well as switched on and off in 1300nm–1600nm.......An electrically controlled liquid crystal photonic-bandgap fiber polarizer is experimentally demonstrated. A maximum 21.3dB electrically tunable polarization extinction ratio is achieved with 45° rotatable transmission axis as well as switched on and off in 1300nm–1600nm....

  17. Polarization-controlled asymmetric excitation of surface plasmons

    KAUST Repository

    Xu, Quan

    2017-08-28

    Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

  18. Solar Illumination Control of the Polar Wind

    Science.gov (United States)

    Maes, L.; Maggiolo, R.; De Keyser, J.; André, M.; Eriksson, A. I.; Haaland, S.; Li, K.; Poedts, S.

    2017-11-01

    Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.

  19. Simulation and Automation of Microwave Frequency Control in Dynamic Nuclear Polarization for Solid Polarized Targets

    Science.gov (United States)

    Perera, Gonaduwage; Johnson, Ian; Keller, Dustin

    2017-09-01

    Dynamic Nuclear Polarization (DNP) is used in most of the solid polarized target scattering experiments. Those target materials must be irradiated using microwaves at a frequency determined by the difference in the nuclear Larmor and electron paramagnetic resonance (EPR) frequencies. But the resonance frequency changes with time as a result of radiation damage. Hence the microwave frequency should be adjusted accordingly. Manually adjusting the frequency can be difficult, and improper adjustments negatively impact the polarization. In order to overcome these difficulties, two controllers were developed which automate the process of seeking and maintaining the optimal frequency: one being a standalone controller for a traditional DC motor and the other a LabVIEW VI for a stepper motor configuration. Further a Monte-Carlo simulation was developed which can accurately model the polarization over time as a function of microwave frequency. In this talk, analysis of the simulated data and recent improvements to the automated system will be presented. DOE.

  20. The essential David Bohm

    CERN Document Server

    Nichol, Lee

    2002-01-01

    There are few scientists of the twentieth century whose life's work has created more excitement and controversy than that of physicist David Bohm (1917-1992). For the first time in a single volume, The Essential David Bohm offers a comprehensive overview of Bohm's original works from a non-technical perspective. Including three chapters of previously unpublished material, and a forward by the Dalai Lama, each reading has been selected to highlight some aspect of the implicate order process, and to provide an introduction to one of the most provocative thinkers of our time.

  1. David, Dr Joy Caesarina

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1982 Section: Medicine. David, Dr Joy Caesarina M.B.B.S., M.S. (Madras). Date of birth: 3 May 1927. Date of death: 20 April 2004. Specialization: Neuropharmacology Last known address: 292, 4th Main, 1st Block, Koramangala, Bengaluru 560 034. YouTube; Twitter; Facebook ...

  2. David Hockney Portraits

    NARCIS (Netherlands)

    Howgate, S.; Stern Shapiro, B.

    2007-01-01

    David Hockney is one of the most significant artists exploring and pushing the boundaries of figurative art today. He has been engaged with portraiture since his teenage years, when he painted Portrait of My Father (1955), and portraits of family, lovers, friends and well-known subjects represent an

  3. Interview with David Moore

    Science.gov (United States)

    Rossman, Allan; Dietz, E. Jacquelin; Moor, David

    2013-01-01

    David Moore is Professor Emeritus of Statistics at Purdue University. He served as the first President of the International Association for Statistical Education (IASE) from 1993-1995 and as President of the American Statistical Association (ASA) in 1998. He is a Fellow of the ASA and of the IMS and was awarded the ASA's Founders Award in…

  4. Gross, Prof. David J

    Indian Academy of Sciences (India)

    Fellow Profile. Elected: 2007 Honorary. Gross, Prof. David J. Date of birth: 1941. Address: Kavli Institute for Theoretical, Physics, University of California, Santa Barbara, CA 93106-4030, U.S.A.. Contact: Office: (+1-805) 893 7337. Residence: (+1-805) 963 8324. Fax: (+1-893) 893 2431. Email: gross@kitp.ucsb.edu. YouTube ...

  5. Recollections of David Marr.

    Science.gov (United States)

    Nishihara, H K

    2012-01-01

    David Marr came to MIT's Artificial Intelligence (AI) Lab in the early 1970s and energized the study of vision at the intersection of computer science, psychology, and neuroscience. As one of his first graduate students, I had the privilege of getting to know him and working with him during that heady period of AI research.

  6. David R Syiemlieh

    Indian Academy of Sciences (India)

    Union Public Service Commission, New Delhi. David R. Syiemlieh, formally a historian, joined as a Professor in the Department of History, NEHU, Shillong, in 1979. Concurrent with this position, he held at different times, Dean of Students' Welfare, Proctor, Director, College Development Council, and Head, Department of ...

  7. David Gale: Restless Pioneer

    Science.gov (United States)

    Meyer, Walter

    2006-01-01

    David Gale was one of the mathematicians responsible for the modern form of the theory of duality in linear programming and the associated proof of the minimax theorem in the theory of games. He is a member of the National Academy of Sciences and is Professor Emeritus of Mathematics and Operations Research at the University of California at…

  8. Polar auxin transport: controlling where and how much

    Science.gov (United States)

    Muday, G. K.; DeLong, A.; Brown, C. S. (Principal Investigator)

    2001-01-01

    Auxin is transported through plant tissues, moving from cell to cell in a unique polar manner. Polar auxin transport controls important growth and developmental processes in higher plants. Recent studies have identified several proteins that mediate polar auxin transport and have shown that some of these proteins are asymmetrically localized, paving the way for studies of the mechanisms that regulate auxin transport. New data indicate that reversible protein phosphorylation can control the amount of auxin transport, whereas protein secretion through Golgi-derived vesicles and interactions with the actin cytoskeleton might regulate the localization of auxin efflux complexes.

  9. Metasurfaces for Terahertz Waves Polarization Control

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Malureanu, Radu; Zalkovskij, Maksim

    in the visible, near infrared or microwave regimes these issues in principle have strong alternatives via a conventional optics or electromagnetic approaches, at terahertz (THz) frequencies metamaterials are often considered as being the unique solution for the encountered problems. Several approaches involving...... that the maximal conversion efficiency with a single metamaterial surface is 50 % in transmission and up to 90% in reflection. However, a double layer transmission converter and a single layer with a metallic mirror can have 100% polarization conversion efficiency. We tested our conclusions numerically reaching...

  10. David Warner (1934 - 2003)

    CERN Multimedia

    2004-01-01

    It is with great sadness that we learned that our friend and former colleague, David Warner, passed away on Christmas Eve. The funeral was held the following Monday. David was a "linac man". His career centred around linacs, but with a multitude of different subjects. He began at CERN by building the 3 MeV linac in the extension of the South Hall. He did pioneering work on this machine, which paved the way towards the design of the Alvarez cavities for the CERN Linac 2, for which he was responsible. After this challenge was successfully finished, David was the first member of the small but growing team, that was in charge of building the LEP Injector Linacs (LIL). After having been recognised as a proton linac expert, he quickly converted to electron linacs where he soon became the respected key expert for the design, parameters and ultimate performance of LIL. His predilection for precise and detailed documentation, and his vision that the know-how acquired with LIL should be preserved a...

  11. Geomagnetic control of polar mesosphere summer echoes

    Directory of Open Access Journals (Sweden)

    J. Bremer

    2000-02-01

    Full Text Available Using observations with the ALOMAR SOUSY radar near Andenes (69.3°N, 16.0°E from 1994 until 1997 polar mesosphere summer echoes (PMSE have been investigated in dependence on geomagnetic K indices derived at the Auroral Observatory Tromsø (69.66°N, 18.94°E. During night-time and morning hours a significant correlation between the signal-to-noise ratio (SNR of the radar results and the geomagnetic K indices could be detected with a maximum correlation near midnight. The correlation becomes markedly smaller in the afternoon and early evening hours with a minimum near 17 UT. This diurnal variation is in reasonable agreement with riometer absorption at Ivalo (68.55°N, 27.28°E and can be explained by the diurnal variation of ionization due to precipitating high energetic particles. Therefore, a part of the diurnal PMSE variation is caused by this particle precipitation. The variability of the solar EUV variation, however, has no significant influence on the PMSE during the observation period.Keywords: Ionosphere (auroral ionosphere - Magnetospheric physics (energetic particles, precipitating - Radio science (remote sensing

  12. Geomagnetic control of polar mesosphere summer echoes

    Directory of Open Access Journals (Sweden)

    J. Bremer

    Full Text Available Using observations with the ALOMAR SOUSY radar near Andenes (69.3°N, 16.0°E from 1994 until 1997 polar mesosphere summer echoes (PMSE have been investigated in dependence on geomagnetic K indices derived at the Auroral Observatory Tromsø (69.66°N, 18.94°E. During night-time and morning hours a significant correlation between the signal-to-noise ratio (SNR of the radar results and the geomagnetic K indices could be detected with a maximum correlation near midnight. The correlation becomes markedly smaller in the afternoon and early evening hours with a minimum near 17 UT. This diurnal variation is in reasonable agreement with riometer absorption at Ivalo (68.55°N, 27.28°E and can be explained by the diurnal variation of ionization due to precipitating high energetic particles. Therefore, a part of the diurnal PMSE variation is caused by this particle precipitation. The variability of the solar EUV variation, however, has no significant influence on the PMSE during the observation period.

    Keywords: Ionosphere (auroral ionosphere - Magnetospheric physics (energetic particles, precipitating - Radio science (remote sensing

  13. Mechanism of anterior-posterior polarity control in planarians

    Energy Technology Data Exchange (ETDEWEB)

    Lange, C.S.; Steele, V.E.

    1978-01-01

    The substance which inhibits brain formation in the regenerating planarian Dugesia etrusca was found to be a large molecule, at least in part protein, which electrophoreses as an electronegative moiety in pH 6.8 buffer. A model is presented, based on this finding and previous studies, which proposes an electrochemical mechanism for the control of polarity and possibly for the maintenance of tissue organization in planarians. It is proposed that a bioelectric field exists and moves the electronegative brain-inhibiting substance in a posterior direction, establishing polarity. This model explains the polarity reversal experiments using external fields and many of the previously unexplained classical planarian experiments. Data are presented demonstrating the existence, magnitude, and polarity of this bioelectric field, which is not greatly altered upon decapitation, all in accord with predictions of the model.

  14. Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

    Science.gov (United States)

    Boll, D. I. R.; Fojón, O. A.

    2017-12-01

    We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

  15. Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

    International Nuclear Information System (INIS)

    Boll, D I R; Fojón, O A

    2017-01-01

    We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets. (paper)

  16. Classical cadherins control nucleus and centrosome position and cell polarity.

    Science.gov (United States)

    Dupin, Isabelle; Camand, Emeline; Etienne-Manneville, Sandrine

    2009-06-01

    Control of cell polarity is crucial during tissue morphogenesis and renewal, and depends on spatial cues provided by the extracellular environment. Using micropatterned substrates to impose reproducible cell-cell interactions, we show that in the absence of other polarizing cues, cell-cell contacts are the main regulator of nucleus and centrosome positioning, and intracellular polarized organization. In a variety of cell types, including astrocytes, epithelial cells, and endothelial cells, calcium-dependent cadherin-mediated cell-cell interactions induce nucleus and centrosome off-centering toward cell-cell contacts, and promote orientation of the nucleus-centrosome axis toward free cell edges. Nucleus and centrosome off-centering is controlled by N-cadherin through the regulation of cell interactions with the extracellular matrix, whereas the orientation of the nucleus-centrosome axis is determined by the geometry of N-cadherin-mediated contacts. Our results demonstrate that in addition to the specific function of E-cadherin in regulating baso-apical epithelial polarity, classical cadherins control cell polarization in otherwise nonpolarized cells.

  17. David Bowie's Hauntology

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    David Bowie's now-defunct rock-opera trilogy's first installment 1. Outside is filled with uncanny mediations of rock music's chameleon. The inner sleeve booklet is titled The Diary of Nathan Adler, or the Ritual Art-Murder of Baby Grace Blue: A non-linear Gothic Drama Hyper-Cycle. Behind this long...... in uncanny forms, just as all images in the booklet are distorted images of Bowie himself, made into uncanny doubles. The story begins with the murder of Baby Grace Blue, who is enacted by Bowie himself. Symbolically, Bowie is murdered by himself, while Baby Grace haunts the entire album's Gothic...

  18. David Livingstone's uvulectomy.

    Science.gov (United States)

    Larner, A J

    2006-05-01

    In April 1852 in Cape Town, South Africa, Dr David Livingstone, then 39 years of age and yet to commence the explorations of Africa which would bring him to public attention, underwent the surgical procedure of uvulectomy. This article reviews the history of Livingstone's uvulectomy and its indications and outcome, as documented by his own writings. The practice of uvulectomy in indigenous African societies and some contemporary ideas about uvulectomy are also considered in order to try to ascertain why Livingstone elected to undergo this procedure.

  19. Design of triple-band polarization controlled terahertz metamaterial absorber

    Science.gov (United States)

    Wang, Ben-Xin; Xie, Qin; Dong, Guangxi; Huang, Wei-Qing

    2018-02-01

    A kind of triple-band polarization tunable terahertz absorber based on a metallic mirror and a metallic patch structure with two indentations spaced by an insulating medium layer is presented. Results prove that three near-perfect absorption peaks with average absorption coefficients of 98.25% are achieved when the polarization angle is equal to zero, and their absorptivities gradually decrease (and even disappear) by increasing the angle of polarization. When the polarization angle is increased to 90°, three new resonance modes with average absorption rates of 96.59% can be obtained. The field distributions are given to reveal the mechanisms of the triple-band absorption and the polarization tunable characteristics. Moreover, by introducing photosensitive silicon materials (its conductivity can be changed by the pump beam) in the indentations of the patch structure, the number of resonance peaks of the device can be actively tuned from triple-band to dual-band. The presented absorbers have potential applications, such as controlling thermal emissivity, and detection of polarization direction of the incident waves.

  20. Polarity Control in Group-III Nitrides beyond Pragmatism

    Science.gov (United States)

    Mohn, Stefan; Stolyarchuk, Natalia; Markurt, Toni; Kirste, Ronny; Hoffmann, Marc P.; Collazo, Ramón; Courville, Aimeric; Di Felice, Rosa; Sitar, Zlatko; Vennéguès, Philippe; Albrecht, Martin

    2016-05-01

    Controlling the polarity of polar semiconductors on nonpolar substrates offers a wealth of device concepts in the form of heteropolar junctions. A key to realize such structures is an appropriate buffer-layer design that, in the past, has been developed by empiricism. GaN or ZnO on sapphire are prominent examples for that. Understanding the basic processes that mediate polarity, however, is still an unsolved problem. In this work, we study the structure of buffer layers for group-III nitrides on sapphire by transmission electron microscopy as an example. We show that it is the conversion of the sapphire surface into a rhombohedral aluminum-oxynitride layer that converts the initial N-polar surface to Al polarity. With the various AlxOyNz phases of the pseudobinary Al2O3 -AlN system and their tolerance against intrinsic defects, typical for oxides, a smooth transition between the octahedrally coordinated Al in the sapphire and the tetrahedrally coordinated Al in AlN becomes feasible. Based on these results, we discuss the consequences for achieving either polarity and shed light on widely applied concepts in the field of group-III nitrides like nitridation and low-temperature buffer layers.

  1. Morphological control and polarization switching in polymer ...

    Indian Academy of Sciences (India)

    Abstract. Liquid crystals dispersed in polymer systems constitute novel class of optical materials. The precise control of the liquid crystal droplet morphology in the polymer matrix is essentially required to meet the pre- requisites of display device. Experiments have been carried out to investigate and identify the material pro-.

  2. Morphological control and polarization switching in polymer ...

    Indian Academy of Sciences (India)

    Liquid crystals dispersed in polymer systems constitute novel class of optical materials. The precise control of the liquid crystal droplet morphology in the polymer matrix is essentially required to meet the prerequisites of display device. Experiments have been carried out to investigate and identify the material properties and ...

  3. Genetic control of organ shape and tissue polarity.

    Directory of Open Access Journals (Sweden)

    Amelia A Green

    2010-11-01

    Full Text Available The mechanisms by which genes control organ shape are poorly understood. In principle, genes may control shape by modifying local rates and/or orientations of deformation. Distinguishing between these possibilities has been difficult because of interactions between patterns, orientations, and mechanical constraints during growth. Here we show how a combination of growth analysis, molecular genetics, and modelling can be used to dissect the factors contributing to shape. Using the Snapdragon (Antirrhinum flower as an example, we show how shape development reflects local rates and orientations of tissue growth that vary spatially and temporally to form a dynamic growth field. This growth field is under the control of several dorsoventral genes that influence flower shape. The action of these genes can be modelled by assuming they modulate specified growth rates parallel or perpendicular to local orientations, established by a few key organisers of tissue polarity. Models in which dorsoventral genes only influence specified growth rates do not fully account for the observed growth fields and shapes. However, the data can be readily explained by a model in which dorsoventral genes also modify organisers of tissue polarity. In particular, genetic control of tissue polarity organisers at ventral petal junctions and distal boundaries allows both the shape and growth field of the flower to be accounted for in wild type and mutants. The results suggest that genetic control of tissue polarity organisers has played a key role in the development and evolution of shape.

  4. Polarization control method for UV writing of advanced bragg gratings

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We report the application of the polarization control method for the UV writing of advanced fiber Bragg gratings (FBG). We demonstrate the strength of the new method for different apodization profiles, including the Sinc-profile and two designs for dispersion-free square filters. The method has...

  5. Polarization-controlled luminaires utilizing multiple Fresnel reflections

    Science.gov (United States)

    Falicoff, Waqidi; Minano, Juan C.; Caulfield, H. John; Alvarez, Roberto

    2003-11-01

    A novel luminaire utilizes repeated Fresnel reflections by angled surfaces to transform a small collimated input beam into a controlled output pattern with a high degree of polarization, either linear or radial. Applications to backlighting, front-lighting, optical communications and automotive lighting will be discussed.

  6. A Star of David catenane.

    Science.gov (United States)

    Leigh, David A; Pritchard, Robin G; Stephens, Alexander J

    2014-11-01

    We describe the synthesis of a [2]catenane that consists of two triply entwined 114-membered rings, a molecular link. The woven scaffold is a hexameric circular helicate generated by the assembly of six tris(bipyridine) ligands with six iron(II) cations, with the size of the helicate promoted by the use of sulfate counterions. The structure of the ligand extension directs subsequent covalent capture of the catenane by ring-closing olefin metathesis. Confirmation of the Star of David topology (two rings, six crossings) is provided by NMR spectroscopy, mass spectrometry and X-ray crystallography. Extraction of the iron(II) ions with tetrasodium ethylenediaminetetraacetate affords the wholly organic molecular link. The self-assembly of interwoven circular frameworks of controlled size, and their subsequent closure by multiple directed covalent bond-forming reactions, provides a powerful strategy for the synthesis of molecular topologies of ever-increasing complexity.

  7. A Star of David catenane

    Science.gov (United States)

    Leigh, David A.; Pritchard, Robin G.; Stephens, Alexander J.

    2014-11-01

    We describe the synthesis of a [2]catenane that consists of two triply entwined 114-membered rings, a molecular link. The woven scaffold is a hexameric circular helicate generated by the assembly of six tris(bipyridine) ligands with six iron(II) cations, with the size of the helicate promoted by the use of sulfate counterions. The structure of the ligand extension directs subsequent covalent capture of the catenane by ring-closing olefin metathesis. Confirmation of the Star of David topology (two rings, six crossings) is provided by NMR spectroscopy, mass spectrometry and X-ray crystallography. Extraction of the iron(II) ions with tetrasodium ethylenediaminetetraacetate affords the wholly organic molecular link. The self-assembly of interwoven circular frameworks of controlled size, and their subsequent closure by multiple directed covalent bond-forming reactions, provides a powerful strategy for the synthesis of molecular topologies of ever-increasing complexity.

  8. Coherent control of optical polarization effects in metamaterials

    Science.gov (United States)

    Mousavi, Seyedmohammad A.; Plum, Eric; Shi, Jinhui; Zheludev, Nikolay I.

    2015-01-01

    Processing of photonic information usually relies on electronics. Aiming to avoid the conversion between photonic and electronic signals, modulation of light with light based on optical nonlinearity has become a major research field and coherent optical effects on the nanoscale are emerging as new means of handling and distributing signals. Here we demonstrate that in slabs of linear material of sub-wavelength thickness optical manifestations of birefringence and optical activity (linear and circular birefringence and dichroism) can be controlled by a wave coherent with the wave probing the polarization effect. We demonstrate this in proof-of-principle experiments for chiral and anisotropic microwave metamaterials, where we show that the large parameter space of polarization characteristics may be accessed at will by coherent control. Such control can be exerted at arbitrarily low intensities, thus arguably allowing for fast handling of electromagnetic signals without facing thermal management and energy challenges. PMID:25755071

  9. Pora prodavat znanija / David Tisch

    Index Scriptorium Estoniae

    Tisch, David

    2006-01-01

    California Ülikooli (Berkeley) professor David Tisch teadmistepõhistest väärtustest ja nende mõjust konkurentsivõimele, konkurentsist innovatsiooniturul, Silicon Valley edu põhjustest, väikeste ja keskmiste ettevõtete osast innovatsioonis. Lisa: David Tisch

  10. Cryogenic control system of the large COMPASS polarized target

    CERN Document Server

    Gautheron, F; Baum, G; Berglund, P; Doshita, N; Görtz, S; Gustafsson, K K; Horikawa, N; Kisselev, Yu V; Koivuniemi, J H; Kondo, K; Meyer, Werner T; Reicherz, G

    2004-01-01

    The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW trademark 6.1 under Windows 2000 trademark . About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle trademark database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

  11. Cryogenic control system of the large COMPASS polarized target

    Science.gov (United States)

    Gautheron, F.; Ball, J.; Baum, G.; Berglund, P.; Doshita, N.; Goertz, St.; Gustafsson, K.; Horikawa, N.; Kisselev, Y.; Koivuniemi, J.; Kondo, K.; Meyer, W.; Reicherz, G.

    2004-06-01

    The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW TM 6.1 under Windows 2000 TM. About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle TM database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

  12. Terahertz transmission control using polarization-independent metamaterials.

    Science.gov (United States)

    Lee, Sang-Hun; Lee, Dong-Kyu; Kim, Chulki; Jhon, Young Min; Son, Joo-Hiuk; Seo, Minah

    2017-05-15

    We present terahertz (THz) transmission control by several uniquely designed patterns of nano-slot antenna array. Collinearly aligned slot antenna arrays have been usually applied to THz filters with frequency band tunability by their geometry. Normally the amplitude in transmission (reflection) in the collinear alignment case can be varied via rotating the azimuthal angle with a sinusoidal trend, which can limit their utilization and performance only at fixed angle between the alignment of the resonant antennas and incident beam polarization. To pursue a variety of metamaterial uses, here, we present polarization-independent THz filters using variously aligned antenna array (asterisk, chlorophyll, and honeycomb patterns) in such counter-intuitive aspects. Besides, unprecedented multi resonance behaviors were observed in chlorophyll and honeycomb patterns, which can be explained with interferences by adjacent structures. The measured spectra were analyzed by harmonic oscillator model with simplified coupling between slots and their adjacent.

  13. Memories of David Kirzhnits

    Science.gov (United States)

    Bolotovsky, B. M.

    2013-06-01

    In the mid-1950s, a new staff member appeared at the Theory Division of the Physical Institute of the Academy of Sciences (FIAN): David Abramovich Kirzhnits. A Moscow State University alumnus, after graduation he had been assigned to a large defense plant in the city of Gorky, where he had worked for several years as an engineer. He was "liberated" from there by Igor Evgenyevich Tamm, our department head, who managed to transfer him to FIAN. Igor Evgenyevich knew D. A. Kirzhnits - they had met in Moscow before Kirzhnits finished university. At that time Kirzhnits was performing thesis work with professor A. S. Kompaneyets as academic adviser. At his adviser's suggestion, D. Kirzhnits consulted with I. E. Tamm on questions pertaining to the thesis topic. I. E. Tamm took a great liking for the diploma student, and he even wanted to recruit D. A. Kirzhnits for the Theory Division immediately after graduation. But at that time (1949) this proved impossible for several reasons. First, D. Kirzhnits was, as they say, an "invalid of the fifth group" - a Jew - which during those years of violent struggle against cosmopolitanismb often proved an obstacle in looking for work. Second, during the years of mass repressions D. Kirzhnits' father had been arrested on treason charges (according to the charges, he had wanted to sell the Far East to Japan). After intensive investigation his father was released, but he lived only a little longer. Reports of this also could have impeded his acceptance. Third, Igor Evgenyevich didn't have enough weight in officials' eyes at that time and so was unable to overcome "first" and "second."...

  14. Controlling Force in Polarization-Maintaining Fiber Fused Biconical Tapering

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2015-01-01

    Full Text Available Fused biconical tapering (FBT is an important method of manufacturing polarization-maintaining fiber (PMF couplers. However, the tension on the ends of the fibers can affect the performance of the coupler. In this paper, a computer-based method of controlling the drawing force was presented. The system includes a drawing mechanism, rotary position encoders, and a control circuit. A three-dimensional model of a permanent magnet and a coil is constructed, and the relationship among the coil current, rotation angle of the clamp, and electromagnetic force is determined using finite element simulations. Electromagnetic force control based on these simulations can be realized. The method is verified experimentally, and it is shown that a drawing force of 0–1.8 gf can be achieved with an error of within 3.04%. This result can be used in the FBT-based manufacture of fiber components such as fiber couplers and gratings.

  15. A programmable metasurface with dynamic polarization, scattering and focusing control

    Science.gov (United States)

    Yang, Huanhuan; Cao, Xiangyu; Yang, Fan; Gao, Jun; Xu, Shenheng; Li, Maokun; Chen, Xibi; Zhao, Yi; Zheng, Yuejun; Li, Sijia

    2016-10-01

    Diverse electromagnetic (EM) responses of a programmable metasurface with a relatively large scale have been investigated, where multiple functionalities are obtained on the same surface. The unit cell in the metasurface is integrated with one PIN diode, and thus a binary coded phase is realized for a single polarization. Exploiting this anisotropic characteristic, reconfigurable polarization conversion is presented first. Then the dynamic scattering performance for two kinds of sources, i.e. a plane wave and a point source, is carefully elaborated. To tailor the scattering properties, genetic algorithm, normally based on binary coding, is coupled with the scattering pattern analysis to optimize the coding matrix. Besides, inverse fast Fourier transform (IFFT) technique is also introduced to expedite the optimization process of a large metasurface. Since the coding control of each unit cell allows a local and direct modulation of EM wave, various EM phenomena including anomalous reflection, diffusion, beam steering and beam forming are successfully demonstrated by both simulations and experiments. It is worthwhile to point out that a real-time switch among these functionalities is also achieved by using a field-programmable gate array (FPGA). All the results suggest that the proposed programmable metasurface has great potentials for future applications.

  16. David Hume on Competent Judges

    Science.gov (United States)

    Eaton, Marcia Muelder

    2004-01-01

    This essay is the eighth in an occasional series on past treatments of major issues in arts education policy from antiquity through the twentieth century. The essay on which it is based, David Hume's "Of the Standard of Taste," originally published in 1757, is too extensive to be reprinted here, but it is easily accessible in the public…

  17. Response to David Temperley's Commentary

    Directory of Open Access Journals (Sweden)

    William Thomson

    2006-09-01

    Full Text Available The author responds to points raised in David Temperley’s commentary, which appeared in Vol. 1, No. 2 of Empirical Musicology Review. The response includes a discussion of strengths and limitations of atemporal models of musical perception, with particular attention to presentations such as those of Carol Krumhansl and Fred Lerdahl.

  18. King, Prof. Sir David Anthony

    Indian Academy of Sciences (India)

    Elected: 1998 Honorary. King, Prof. Sir David Anthony Sc.D., FRS. Date of birth: 12 August 1939. Address: Chief Scientific Adivser & Head, Office of Science and Innovation, London SW1H 0ET, U.K.. Contact: Office: (+44-020) 7215 3821. Fax: (+44-020) 7215 0314. Email: mpst.king@dti.gsi.gov.uk, dak10@cus.cam.ac.uk.

  19. Optically controlled polarization in highly oriented ferroelectric thin films

    Science.gov (United States)

    Borkar, Hitesh; Tomar, M.; Gupta, Vinay; Katiyar, Ram S.; Scott, J. F.; Kumar, Ashok

    2017-08-01

    The out-of-plane and in-plane polarization of (Pb0.6Li0.2Bi0.2)(Zr0.2Ti0.8)O3 (PLBZT) thin film has been studied in the dark and under illumination from a weak light source of a comparable bandgap. A highly oriented PLBZT thin film was grown on a LaNiO3/LaAlO3 substrate by pulsed laser deposition; it showed well-saturated polarization which was significantly enhanced under light illumination. We employed two configurations for polarization characterization: the first deals with out-of-plane polarization with a single capacitor under investigation, whereas the second uses two capacitors connected in series via the bottom electrode. Two different configurations were illuminated using different energy sources and their effects were studied. The latter configuration shows a significant change in polarization under light illumination that may provide an extra degree of freedom for device miniaturization. The polarization was also tested using positive-up and negative-down measurements, confirming robust polarization and its switching under illumination.

  20. Control of Domain Wall Polarity by Current Pulses

    Science.gov (United States)

    Vanhaverbeke, A.; Bischof, A.; Allenspach, R.

    2008-09-01

    Direct observation of current-induced propagation of purely transverse magnetic domain walls with spin-polarized scanning electron microscopy is reported in Fe30Ni70 nanowires. After propagation, the domain walls keep their transverse nature but switch polarity in some cases. For uniform Ni70Fe30 wires, the effect is random and illustrates domain-wall propagation above the Walker threshold. In the case of Ni70Fe30/Fe wires, the transverse magnetization component in the wall is entirely determined by the polarity of the current pulse, an effect that is not reconciled by present theories even when taking into account the nonuniform Oersted field generated by the current.

  1. Polarity controlled reaction path and kinetics of thermal cis-to-trans isomerization of 4-aminoazobenzene.

    Science.gov (United States)

    Joshi, Neeraj Kumar; Fuyuki, Masanori; Wada, Akihide

    2014-02-20

    Spectral and kinetic behavior of thermal cis-to-trans isomerization of 4-aminoazobenzene (AAB) is examined in various solvents of different polarities. In contrast to azobenzene (AB), it is found the rate of thermal isomerization of AAB is highly dependent on solvent polarity. Accelerated rates are observed in polar solvents as compared to nonpolar solvents. Moreover, a decrease in the barrier height with an increase in medium polarity is observed. Our observations suggest that inversion is the preferred pathway in cis-to-trans thermal isomerization in a nonpolar medium; however, in a polar medium, the isomerization path deviates from the inversion route and rotational behavior is incorporated. Differences in the kinetics and in mechanisms of isomerization in different media are rationalized in terms of modulation in barrier height by polarity of the medium and solute-solvent interaction. It is found that kinetics as well as the mechanism of thermal isomerization in AAB is controlled by the polarity of the medium.

  2. Polarity Control and Growth of Lateral Polarity Structures in AlN

    Science.gov (United States)

    2013-05-10

    AlN, lateral polar structures, metal organic chemical vapor deposition Ronny Kirste, Seiji Mita , Lindsay Hussey, Marc Hoffmann, Wei Guo, Isaac Bryan...structures in AlN Ronny Kirste,1 Seiji Mita ,2 Lindsay Hussey,1 Marc P. Hoffmann,1 Wei Guo,1 Isaac Bryan,1 Zachary Bryan,1 James Tweedie,1 Jinqiao Xie,2...and H. X. Jiang, Appl. Phys. Lett. 89(21), 213510–213513 (2006). 2N. Dietz, M. Alevli, R. Atalay, G. Durkaya, R. Collazo, J. Tweedie, S. Mita , and Z

  3. Volume production of polarization controlled single-mode VCSELs

    Science.gov (United States)

    Grabherr, Martin; King, Roger; Jäger, Roland; Wiedenmann, Dieter; Gerlach, Philipp; Duckeck, Denise; Wimmer, Christian

    2008-02-01

    Over the past 3 years laser based tracking systems for optical PC mice have outnumbered the traditional VCSEL market datacom by far. Whereas VCSEL for datacom in the 850 nm regime emit in multipe transverse modes, all laser based tracking systems demand for single-mode operation which require advanced manufacturing technology. Next generation tracking systems even require single-polarization characteristics in order to avoid unwanted movement of the pointer due to polarization flips. High volume manufacturing and optimized production methods are crucial for achieving the addressed technical and commercial targets of this consumer market. The resulting ideal laser source which emits single-mode and single-polarization at low cost is also a promising platform for further applications like tuneable diode laser absorption spectroscopy (TDLAS) or miniature atomic clocks when adapted to the according wavelengths.

  4. Polarity control of spindle positioning in the C. elegans embryo

    NARCIS (Netherlands)

    Fielmich, Lars-Eric; van den Heuvel, Sander

    2015-01-01

    Cell and tissue polarity guide a large variety of developmental processes, in-cluding the choice between symmetric and asymmetric cell division. Asymmetric divisions create cell diversity and are needed for maintenance of tissue specific stem cells. Symmetric divisions, on the other hand, promote

  5. David Owen Williams (1944 - 2006)

    CERN Document Server

    2006-01-01

    Many people, not only at CERN but also throughout the world, were saddened to learn that their friend and colleague David Williams had passed away in the early hours of Tuesday 24 October. His death came after a year of fighting cancer with all of his usual determination and optimism. Even days before the end he was still welcoming to visitors, and was alert and interested in all their news. Born in 1944, David came to CERN from the University of Cambridge in 1966, with a degree in Physics and Computer Science. Joining what at the time was called the Documents and Data (DD) Division, in the earlier part his career he worked first on software for analysis of bubble chamber photographs, subsequently leading the group that supported experiments with 'hybrids' of bubble chambers and electronic detectors and then the group supporting online computing in experiments. He thus witnessed all of the enormous changes that took place in particle physics as the era of bubble chambers came to an end and the availability ...

  6. Distributed Access View Integrated Database (DAVID) system

    Science.gov (United States)

    Jacobs, Barry E.

    1991-01-01

    The Distributed Access View Integrated Database (DAVID) System, which was adopted by the Astrophysics Division for their Astrophysics Data System, is a solution to the system heterogeneity problem. The heterogeneous components of the Astrophysics problem is outlined. The Library and Library Consortium levels of the DAVID approach are described. The 'books' and 'kits' level is discussed. The Universal Object Typer Management System level is described. The relation of the DAVID project with the Small Business Innovative Research (SBIR) program is explained.

  7. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine

    NARCIS (Netherlands)

    Klunder, Leon J.; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C. D.

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we

  8. David Mechanic: Professional Zombie Hunter.

    Science.gov (United States)

    Hafferty, Frederic W; Tilburt, Jon

    2016-08-01

    Within the fields of medicine and sociology, the descriptor "profession" (along with its brethren: profession, professionalization, and professionalism) has had a rich etymological history, with terms taking on different meanings at different times-sometimes trespassing into shibboleth and jargon. This etymological journey has co-evolved with the career of David Mechanic to whom this issue of the Journal of Health Politics, Policy and Law is devoted. We exploit a provocative metaphor applied to Mechanic's work on the challenges facing medicine as a profession as a playful exegesis on what we call "profession" to excavate an ensconced and encrusted domain of health jargon operating at the tensive interface of society and modern medical work. Copyright © 2016 by Duke University Press.

  9. Low-Dispersion Fibre Bragg Gratings Written Using the Polarization Control Method

    DEFF Research Database (Denmark)

    Deyerl, Hans Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We present two fibre Bragg gratings with reduced in-band dispersion for DWDM applications. The gratings were designed by the inverse scattering method and fabricated using the novel polarization control method for UV-writing of advanced gratings.......We present two fibre Bragg gratings with reduced in-band dispersion for DWDM applications. The gratings were designed by the inverse scattering method and fabricated using the novel polarization control method for UV-writing of advanced gratings....

  10. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine.

    Science.gov (United States)

    Klunder, Leon J; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C D

    2017-07-05

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we highlight recent advances with regard to the molecular mechanisms of cell polarity-controlled epithelial homeostasis and immunity in the human intestine. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  11. David Schwartz | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    David Schwartz is the Director of IDRC's Donor Partnerships Division. David joined IDRC in 2002 and has held the director post since 2010. His previous experience includes working in the financial sector at CIBC World Markets and field work on commercializing microfinance in Bolivia. He holds a master's in ...

  12. Do Surrealismo em David Lynch

    Directory of Open Access Journals (Sweden)

    Mirian Tavares

    2009-01-01

    Full Text Available O surrealismo, como a arte do seu tempo, propõe uma nova estética, capaz de extrair o belo do absurdo e de instaurar o desvio para que daí surja, de fato, o real. Através da análise de algumas obras de David Lynch e dos livros Les champs magnétiques de Breton e Philippe Soupault e Poisson soluble, de Breton, irei mostrar a pertinência da designação surrealista para a obra do cineasta norte-americano. Lynch, como os surrealistas, constrói uma operação dialética entre o racional/irracional. Ao mesmo tempo em que opera no campo artístico em direção à irracionalidade absoluta, Lynch não nega a sua inserção na sociedade. Acredito que o realizador, como os surrealistas, tenha conseguido encontrar um equilíbrio entre as duas formas de se estar no mundo, racional/irracional, jogando com suas antíteses. O prazer do jogo surrealista consiste em ir até as profundezas do inconsciente e retornar com matéria suficiente para fazer uma obra de arte.Surrealism, as the art of its time, proposes a new aesthetics, one that is able to extract the beautiful from the absurd and to establish the swerve from the standard, from which, in fact, the real comes through. Through the analysis of some works by David Lynch, of Breton and Soupault's Les champs magnétiques, and of Breton's Poisson soluble, I will attempt to show the relevance of the surrealist designation for the work of the American filmmaker. Lynch, like the surrealists, builds a dialectic operation between the rational and the irrational. While operating in the artistic field towards absolute irrationality, Lynch does not deny its role in society. It is my belief that the director, as the surrealists, has managed to find a balance between the two ways of being in the world: rational and irrational; by playing with their antitheses. The pleasure of the surrealist game is to go to the depths of the unconscious and return with sufficient material to make a work of art out of it.

  13. Automated polarization control for the precise alignment of laser-induced self-organized nanostructures

    Science.gov (United States)

    Hermens, Ulrike; Pothen, Mario; Winands, Kai; Arntz, Kristian; Klocke, Fritz

    2018-02-01

    Laser-induced periodic surface structures (LIPSS) found in particular applications in the fields of surface functionalization have been investigated since many years. The direction of these ripple structures with a periodicity in the nanoscale can be manipulated by changing the laser polarization. For industrial use, it is useful to manipulate the direction of these structures automatically and to obtain smooth changes of their orientation without any visible inhomogeneity. However, currently no system solution exists that is able to control the polarization direction completely automated in one software solution so far. In this paper, a system solution is presented that includes a liquid crystal polarizer to control the polarization direction. It is synchronized with a scanner, a dynamic beam expander and a five axis-system. It provides fast switching times and small step sizes. First results of fabricated structures are also presented. In a systematic study, the conjunction of LIPSS with different orientation in two parallel line scans has been investigated.

  14. High Efficacy Green LEDs by Polarization Controlled MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2013-03-31

    Amazing performance in GaInN/GaN based LEDs has become possible by advanced epitaxial growth on a wide variety of substrates over the last decade. An immediate push towards product development and worldwide competition for market share have effectively reduced production cost and generated substantial primary energy savings on a worldwide scale. At all times of the development, this economic pressure forced very fundamental decisions that would shape huge industrial investment. One of those major aspects is the choice of epitaxial growth substrate. The natural questions are to what extend a decision for a certain substrate will limit the ultimate performance and to what extent, the choice of a currently more expensive substrate such as native GaN could overcome any of the remaining performance limitations. Therefore, this project has set out to explore what performance characteristic could be achieved under the utilization of bulk GaN substrate. Our work was guided by the hypotheses that line defects such as threading dislocations in the active region should be avoided and the huge piezoelectric polarization needs to be attenuated – if not turned off – for higher performing LEDs, particularly in the longer wavelength green and deep green portions of the visible spectrum. At their relatively lower performance level, deep green LEDs are a stronger indicator of relative performance improvements and seem particular sensitive to the challenges at hand.

  15. Planar cell polarity breaks bilateral symmetry by controlling ciliary positioning.

    Science.gov (United States)

    Song, Hai; Hu, Jianxin; Chen, Wen; Elliott, Gene; Andre, Philipp; Gao, Bo; Yang, Yingzi

    2010-07-15

    Defining the three body axes is a central event of vertebrate morphogenesis. Establishment of left-right (L-R) asymmetry in development follows the determination of dorsal-ventral and anterior-posterior (A-P) body axes, although the molecular mechanism underlying precise L-R symmetry breaking in reference to the other two axes is still poorly understood. Here, by removing both Vangl1 and Vangl2, the two mouse homologues of a Drosophila core planar cell polarity (PCP) gene Van Gogh (Vang), we reveal a previously unrecognized function of PCP in the initial breaking of lateral symmetry. The leftward nodal flow across the posterior notochord (PNC) has been identified as the earliest event in the de novo formation of L-R asymmetry. We show that PCP is essential in interpreting the A-P patterning information and linking it to L-R asymmetry. In the absence of Vangl1 and Vangl2, cilia are positioned randomly around the centre of the PNC cells and nodal flow is turbulent, which results in disrupted L-R asymmetry. PCP in mouse, unlike what has been implicated in other vertebrate species, is not required for ciliogenesis, cilium motility, Sonic hedgehog (Shh) signalling or apical docking of basal bodies in ciliated tracheal epithelial cells. Our data suggest that PCP acts earlier than the unidirectional nodal flow during bilateral symmetry breaking in vertebrates and provide insight into the functional mechanism of PCP in organizing the vertebrate tissues in development.

  16. Control of polarization rotation in nonlinear propagation of fully structured light

    Science.gov (United States)

    Gibson, Christopher J.; Bevington, Patrick; Oppo, Gian-Luca; Yao, Alison M.

    2018-03-01

    Knowing and controlling the spatial polarization distribution of a beam is of importance in applications such as optical tweezing, imaging, material processing, and communications. Here we show how the polarization distribution is affected by both linear and nonlinear (self-focusing) propagation. We derive an analytical expression for the polarization rotation of fully structured light (FSL) beams during linear propagation and show that the observed rotation is due entirely to the difference in Gouy phase between the two eigenmodes comprising the FSL beams, in excellent agreement with numerical simulations. We also explore the effect of cross-phase modulation due to a self-focusing (Kerr) nonlinearity and show that polarization rotation can be controlled by changing the eigenmodes of the superposition, and physical parameters such as the beam size, the amount of Kerr nonlinearity, and the input power. Finally, we show that by biasing cylindrical vector beams to have elliptical polarization, we can vary the polarization state from radial through spiral to azimuthal using nonlinear propagation.

  17. Velocity barrier-controlled of spin-valley polarized transport in monolayer WSe2 junction

    Science.gov (United States)

    Qiu, Xuejun; Lv, Qiang; Cao, Zhenzhou

    2018-05-01

    In this work, we have theoretically investigated the influence of velocity barrier on the spin-valley polarized transport in monolayer (ML) WSe2 junction with a large spin-orbit coupling (SOC). Both the spin-valley resolved transmission probabilities and conductance are strong dependent on the velocity barrier, as the velocity barrier decreases to 0.06, a spin-valley polarization of exceeding 90% is observed, which is distinct from the ML MoS2 owing to incommensurable SOC. In addition, the spin-valley polarization is further increased above 95% in a ML WSe2 superlattice, in particular, it's found many extraordinary velocity barrier-dependent transport gaps for multiple barrier due to evanescent tunneling. Our results may open an avenue for the velocity barrier-controlled high-efficiency spin and valley polarizations in ML WSe2-based electronic devices.

  18. Independent control of the vortex chirality and polarity in a pair of magnetic nanodots

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junqin; Wang, Yong, E-mail: wangyong@sinap.ac.cn; Cao, Jiefeng; Meng, Xiangyu; Zhu, Fangyuan; Wu, Yanqing; Tai, Renzhong

    2017-08-01

    Independent control of the vortex chirality and polarity is realized by changing the in-plane magnetic field direction in nanodot pair through Object Oriented Micromagnetic Framework (OOMMF) simulation. The two magnetic circles are close to each other and have magnetic interaction. The two circles always have the same polarity and opposite chirality at every remanent state. There are totally four predictable magnetic states in the nanodot pair which can be obtained in the remanent state relaxed from the saturation state along all possible directions. An explanation on the formation of vortex states is given by vortex dynamics. The vortex states are stable in large out-of-plane magnetic field which is in a direction opposite to the vortex polarity. The geometry of the nanodot pair gives a way to easily realize a vortex state with specific polarity and chirality.

  19. Electrooptic Modulators with Controlled Frequency Responses by Using Nonperiodically Polarization-Reversed Structure

    Directory of Open Access Journals (Sweden)

    Ha Viet Pham

    2008-01-01

    Full Text Available We discuss a new method to design traveling-wave electrooptic modulators with controlled frequency responses using nonperiodically polarization-reversed structure. Using our method, the frequency responses of both magnitude and phase of modulation index are controllable. Several electrooptic modulators for advanced modulation formats such as duobinary modulation and wideband single-sideband modulation are proposed.

  20. Moeten we David en Patrick beter informeren?

    OpenAIRE

    Roels, Frank

    2018-01-01

    David Van Reybrouck and Patrick Loobuyck were elected as 2nd and 3rd influential Flemish intellectual. Their opinion about the social democrats, and about the course of morals in schools (as expressed in an interview), is not based on primary sources. We show that political parties and trade unions provide lots of information that however is ignored by commercial media. This leads to incomplete and false perceptions. David and Patrick also propose to introduce a mandatory course about ethics ...

  1. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    International Nuclear Information System (INIS)

    Longhi, E C; Bencok, P; Dobrynin, A; Rial, E C M; Rose, A; Steadman, P; Thompson, C; Thomson, A; Wang, H

    2013-01-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  2. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    Science.gov (United States)

    Longhi, E. C.; Bencok, P.; Dobrynin, A.; Rial, E. C. M.; Rose, A.; Steadman, P.; Thompson, C.; Thomson, A.; Wang, H.

    2013-03-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  3. Dynamic nuclear polarization and optimal control spatial-selective 13C MRI and MRS

    DEFF Research Database (Denmark)

    Vinding, Mads Sloth; Laustsen, Christoffer; Maximov, Ivan I.

    2013-01-01

    Aimed at 13C metabolic magnetic resonance imaging (MRI) and spectroscopy (MRS) applications, we demonstrate that dynamic nuclear polarization (DNP) may be combined with optimal control 2D spatial selection to simultaneously obtain high sensitivity and well-defined spatial restriction. This is ach......Aimed at 13C metabolic magnetic resonance imaging (MRI) and spectroscopy (MRS) applications, we demonstrate that dynamic nuclear polarization (DNP) may be combined with optimal control 2D spatial selection to simultaneously obtain high sensitivity and well-defined spatial restriction....... This is achieved through the development of spatial-selective single-shot spiral-readout MRI and MRS experiments combined with dynamic nuclear polarization hyperpolarized [1-13C]pyruvate on a 4.7T pre-clinical MR scanner. The method stands out from related techniques by facilitating anatomic shaped region...

  4. Controlled release of cytokines using silk-biomaterials for macrophage polarization.

    Science.gov (United States)

    Reeves, Andrew R D; Spiller, Kara L; Freytes, Donald O; Vunjak-Novakovic, Gordana; Kaplan, David L

    2015-12-01

    Polarization of macrophages into an inflammatory (M1) or anti-inflammatory (M2) phenotype is important for clearing pathogens and wound repair, however chronic activation of either type of macrophage has been implicated in several diseases. Methods to locally control the polarization of macrophages is of great interest for biomedical implants and tissue engineering. To that end, silk protein was used to form biopolymer films that release either IFN-γ or IL-4 to control the polarization of macrophages. Modulation of the solubility of the silk films through regulation of β-sheet (crystalline) content enabled a short-term release (4-8 h) of either cytokine, with smaller amounts released out to 24 h. Altering the solubility of the films was accomplished by varying the time that the films were exposed to water vapor. The released IFN-γ or IL-4 induced polarization of THP-1 derived macrophages into the M1 or M2 phenotypes, respectively. The silk biomaterials were able to release enough IFN-γ or IL-4 to repolarize the macrophage from M1 to M2 and vice versa, demonstrating the well-established plasticity of macrophages. High β-sheet content films that are not soluble and do not release the trapped cytokines were also able to polarize macrophages that adhered to the surface through degradation of the silk protein. Chemically conjugating IFN-γ to silk films through disulfide bonds allowed for longer-term release to 10 days. The release of covalently attached IFN-γ from the films was also able to polarize M1 macrophages in vitro. Thus, the strategy described here offers new approaches to utilizing biomaterials for directing the polarization of macrophages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Dr. David Syz, State Secretary for Economic Affairs, Switzerland

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    Photo 01: Dr. David Syz (left) with Professor Roger Cashmore, Research Director for Collider Programmes.Photo 02: Dr. David Syz signing the VIP visitors' book, with Prof. Roger Cashmore.Photo 03: Dr. David Syz signing the VIP visitors' book.Photo 04: Handshake between Dr. David Syz (left) and Prof. Roger Cashmore.

  6. Control of radial propagation and polarity in a plasma jet in surrounding Ar

    Science.gov (United States)

    Gong, W.; Yue, Y.; Ma, F.; Yu, F.; Wan, J.; Nie, L.; Bazaka, K.; Xian, Y.; Lu, X.; Ostrikov, K.

    2018-01-01

    In recent years, the use of shielding gas to prevent the diffusion of the ambient air, particularly oxygen and nitrogen species, into the effluent of the atmospheric pressure plasma jet, and thus control the nature of chemical species used in the plasma treatment has increased. In this paper, the radial propagation of a plasma jet in ambient Ar is examined to find the key determinants of the polarity of plasma jets. The dynamics of the discharge reveal that the radial diffusion discharge is a special phenomenon observed only at the falling edge of the pulses. The radial transport of electrons, which is driven by the radial component of the applied electric field at the falling edge of the pulse, is shown to play an important role in increasing the seed electron density in the surrounding Ar. This result suggests a method to provide seed electrons at atmospheric pressure with a negative discharge. The polarity of the plasma jet is found to be determined by the pulse width rather than the polarity of the applied voltage, as it dictates the relative difference in the intensity of the two discharges in a single pulse, where the stronger discharge in a pulse dominates the behavior of the plasma jet. Accordingly, a method to control the polarity of a plasma jet through varying the pulse width is developed. Since plasma jets of different polarities differ remarkably in terms of their characteristics, the method to control the polarity reported in this paper will be of use for such applications as plasma-enhanced processing of materials and plasma biomedicine.

  7. Control of radial propagation and polarity in a plasma jet in surrounding Ar

    KAUST Repository

    Gong, W.

    2018-01-08

    In recent years, the use of shielding gas to prevent the diffusion of the ambient air, particularly oxygen and nitrogen species, into the effluent of the atmospheric pressure plasma jet, and thus control the nature of chemical species used in the plasma treatment has increased. In this paper, the radial propagation of a plasma jet in ambient Ar is examined to find the key determinants of the polarity of plasma jets. The dynamics of the discharge reveal that the radial diffusion discharge is a special phenomenon observed only at the falling edge of the pulses. The radial transport of electrons, which is driven by the radial component of the applied electric field at the falling edge of the pulse, is shown to play an important role in increasing the seed electron density in the surrounding Ar. This result suggests a method to provide seed electrons at atmospheric pressure with a negative discharge. The polarity of the plasma jet is found to be determined by the pulse width rather than the polarity of the applied voltage, as it dictates the relative difference in the intensity of the two discharges in a single pulse, where the stronger discharge in a pulse dominates the behavior of the plasma jet. Accordingly, a method to control the polarity of a plasma jet through varying the pulse width is developed. Since plasma jets of different polarities differ remarkably in terms of their characteristics, the method to control the polarity reported in this paper will be of use for such applications as plasma-enhanced processing of materials and plasma biomedicine.

  8. Plasmonic Dimer Metamaterials and Metasurfaces for Polarization Control of Terahertz and Optical Waves

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Zalkovskij, Maksim; Malureanu, Radu

    2013-01-01

    We explore the capabilities of planar metamaterials and metasurfaces to control and transform the polarization of electromagnetic radiation, and present a detailed covariant multipole theory of dimer-based metamaterials. We show that various optical properties, such as optical activity, elliptical...... dichroism or polarization conversion can be achieved in metamaterials made of simple shapes, such as nanorods, just by varying their geometrical arrangement. By virtue of the Babinet principle, the proposed theory is extended to inverted structures (membranes) where rods are replaced by slots. Such free...

  9. A Localized Complex of Two Protein Oligomers Controls the Orientation of Cell Polarity

    Directory of Open Access Journals (Sweden)

    Adam M. Perez

    2017-02-01

    Full Text Available Signaling hubs at bacterial cell poles establish cell polarity in the absence of membrane-bound compartments. In the asymmetrically dividing bacterium Caulobacter crescentus, cell polarity stems from the cell cycle-regulated localization and turnover of signaling protein complexes in these hubs, and yet the mechanisms that establish the identity of the two cell poles have not been established. Here, we recapitulate the tripartite assembly of a cell fate signaling complex that forms during the G1-S transition. Using in vivo and in vitro analyses of dynamic polar protein complex formation, we show that a polymeric cell polarity protein, SpmX, serves as a direct bridge between the PopZ polymeric network and the cell fate-directing DivJ histidine kinase. We demonstrate the direct binding between these three proteins and show that a polar microdomain spontaneously assembles when the three proteins are coexpressed heterologously in an Escherichia coli test system. The relative copy numbers of these proteins are essential for complex formation, as overexpression of SpmX in Caulobacter reorganizes the polarity of the cell, generating ectopic cell poles containing PopZ and DivJ. Hierarchical formation of higher-order SpmX oligomers nucleates new PopZ microdomain assemblies at the incipient lateral cell poles, driving localized outgrowth. By comparison to self-assembling protein networks and polar cell growth mechanisms in other bacterial species, we suggest that the cooligomeric PopZ-SpmX protein complex in Caulobacter illustrates a paradigm for coupling cell cycle progression to the controlled geometry of cell pole establishment.

  10. David i fortællingen i verden

    DEFF Research Database (Denmark)

    Hasselbalch, Trine Bjørnung

    2013-01-01

    Interpretations of the narratives about David in the Books of Samuel can be divided roughly into works that understand them one way or the other as products of history, and works that tend to disregard questions about their historical conditions. But neither strategy – studying the meaning...... of their production in terms of history, or not at all – can bring out all facets in the meaning of producing these narratives. Here a spatial approach is taken, according to which the production of literature is not simply caused by historical contexts that can be accounted for in research; it takes place...... in unresolved social situations of which the authors are not in control. From this perspective, some nuances are suggested about how the writing of the David narratives could be meaningful to their author(s)....

  11. Polarization control of high transmission/reflection switching by all-dielectric metasurfaces

    Science.gov (United States)

    Shibanuma, Toshihiko; Maier, Stefan A.; Albella, Pablo

    2018-02-01

    Metasurfaces built of high refractive dielectric nanostructures could play a key role in controlling the electromagnetic wave propagation, due to their low energy losses and their ability to excite not only electric but also magnetic resonances. In this study, we theoretically and experimentally demonstrate that an array of high-index dielectric nanodimers can perform as tuneable metasurfaces that can be switched from a high transmitter to a high reflector, by just changing the linear polarization of excitation. The incident polarization alters the hybridization mode of the excited electric and magnetic dipoles in the dimer, and this leads to either spectral overlap or separation of the two dipoles. The hybridization of the electric and magnetic modes modifies the effective permittivity and permeability of the tuneable dielectric metasurface, exhibiting the high transmission and reflection that can be easily switched by simply changing the linear polarization.

  12. Design of a polarization-controlled launcher for the ECH system on J-TEXT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.H.; Xia, D.H., E-mail: xiadh@hust.edu.cn; Sun, D.L.; Wang, Z.J.; Xiao, J.X.; Zeng, Z.; Cui, F.T.; Yu, Z.X.; Zhuang, G.

    2016-11-15

    Highlights: • A polarization-controlled launcher is designed for the ECH system on J-TEXT. • The coordinate transformation method is used for the polarizer design of the launcher. • O-mode purity of no less than 97% for all possible injection can be achieved with this launcher. - Abstract: Based on main components including gyrotrons, magnets, auxiliary power supplies, transmission parts, etc. donated by the Culham Science Center, an electron cyclotron heating (ECH) system with four 60 GHz/200 kW/0.5 s subunits is being developed on J-TEXT for effective plasma heating and MHD studies. A launcher has been designed to inject the beam of the first subunit into plasma with the desired polarization and direction. The launcher mainly consists of a polarizer, an ellipsoidal mirror, a steerable flat mirror and a gate valve. When the beam arrives at the launcher, it is firstly diffracted by the polarizer and then focused by the ellipsoidal mirror. Finally, the beam is delivered to plasma by the steerable mirror. Owing to the limited space of the port for beam injection, the scanning range in both the toroidal and poloidal direction is about −8° to 8°. With optimization design, the available mode purity for all possible injection is no less than 97% and the beam radius at the center of plasma is about 38 mm, making it possible for high efficient coupling and localized absorption of the wave power.

  13. Obituary: David Stanley Evans, 1916-2004

    Science.gov (United States)

    Bash, Frank N.

    2005-12-01

    David Stanley Evans died on 14 November 2004 in Austin, Texas. He was a noted observational astronomer whose career was divided between South Africa and Texas. He also used the extensive historical collections at the University of Texas to write several books on the history of astronomy. He was born in Cardiff, Wales on 28 January 1916. David received his BA degree in mathematics in 1937 from Kings College, Cambridge. He became a PhD student at Cambridge Observatory in 1937, and was one of Sir Arthur Eddington's last surviving students. He received his PhD degree in 1941 with a dissertation entitled, "The Formation of the Balmer Series of Hydrogen in Stellar Atmospheres." He was a conscientious objector to war and, thus, spent the war years at Oxford working with physicist Kurt Mendelssohn on medical problems, involving cadavers, relating to the war. During these years, David was scientific editor of "Discovery", and he was editor of "The Observatory". David left England in 1946 in order to take up the position of Second Assistant at the Radcliffe Observatory, Pretoria, South Africa. He and H. Knox Shaw were the entire staff after R. O. Redman left, and they aluminized and installed the mirrors in the 74-inch telescope. His notable scientific contribution was to use lunar occultations to measure stellar angular diameters during the 1950s. He succeeded in determining the angular diameter of Antares and determined that Arcturus was not circular but had an elliptical shape. The elliptical shape was later shown to be an instrumental artifact, but the utility of using lunar occultations to measure stellar diameters and stellar multiplicity was conclusively demonstrated. T. Gold presented David's paper on lunar occultation angular diameters at the January 1953 meeting of the Royal Astronomical Society. For the rest of his life, David resented Gold's remarks, because he felt that he had been ridiculed. By 1953, David Evans was Chief Assistant at the Royal Observatory

  14. Improved PHIP polarization using a precision, low noise, voltage controlled current source.

    Science.gov (United States)

    Agraz, Jose; Grunfeld, Alexander; Cunningham, Karl; Li, Debiao; Wagner, Shawn

    2013-10-01

    Existing para-hydrogen induced polarization (PHIP) instrumentation relies on magnetic fields to hyperpolarize substances. These hyperpolarized substances have enhanced magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for MRI at the molecular level. Required magnetic fields are generated by energizing a solenoid coil with current produced by a voltage controlled voltage source (VCVS), also known as a power supply. A VCVS lacks the current regulation necessary to keep magnetic field fluctuations to a minimum, which results in low PHIP polarization. A voltage controlled current source (VCCS) is an electric circuit that generates a steady flow of electrons proportional to an input voltage. A low noise VCCS provides the solenoid current flow regulation necessary to generate a stable static magnetic field (Bo). We discuss the design and implementation of a low noise, high stability, VCCS for magnetic field generation with minimum variations. We show that a precision, low noise, voltage reference driving a metal oxide semiconductor field effect transistor (MOSFET) based current sink, results in the current flow control necessary for generating a low noise and high stability Bo. In addition, this work: (1) compares current stability for ideal VCVS and VCCS models using transfer functions (TF), (2) develops our VCCS design's TF, (3) measures our VCCS design's thermal & 1/f noise, and (4) measures and compares hydroxyethyl-propionate (HEP) polarization obtained using a VCVS and our VCCS. The hyperpolarization of HEP was done using a PHIP instrument developed in our lab. Using our VCCS design, HEP polarization magnitude data show a statistically significant increase in polarization over using a VCVS. Circuit schematic, bill of materials, board layout, TF derivation, and Matlab simulations code are included as supplemental files. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Family Matters: A Conversation with David Popenoe

    Science.gov (United States)

    Iannone, Carol

    2009-01-01

    This article presents an interview with Professor David Popenoe, author of the controversial book "Disturbing the Nest: Family Change and Decline in Modern Societies" (1988). Popenoe heads the National Marriage Project at Rutgers University, where he taught sociology for forty-five years until his recent retirement. Here, Popenoe discusses his…

  16. David Bohm’s Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Rodrigo Siqueira-Batista

    2010-05-01

    Full Text Available Bohm’s interpretation of Quantum Mechanics appears as one of the main alternatives to the hegemonic model proposed by the Copenhagen School. This works aims at making a concise presentation of the outlines and the main conceptual framework of the approach followed by David Bohm.

  17. David Ben-Gurion: A Creative Leader

    Science.gov (United States)

    Rosemarin, Shoshana

    2014-01-01

    David Ben-Gurion (1886-1973), the first Prime Minister of Israel, is included in Pasternak's (2001) list of the nine most memorable leaders of the twentieth century. All of them are remembered for the reforms they initiated. Roosevelt (USA), Stalin (Russia), Castro (Cuba), and Thatcher (England) focused on social-economical changes, whereas Gandhi…

  18. Control of the spin polarization of photoelectrons/photoions using short laser pulses

    International Nuclear Information System (INIS)

    Nakajima, Takashi

    2004-01-01

    We present a generic pump-probe scheme to control spin polarization of photoelectrons/photoions by short laser pulses. By coherently exciting fine structure manifolds of a multi-valence-electron system by the pump laser, a superposition of fine structure states is created. Since each fine structure state can be further decomposed into a superposition of various spin states of valence electrons, each spin component evolves differently in time. This means that varying the time delay between the pump and probe lasers leads to the control of spin states. Specific theoretical results are presented for two-valence-electron atoms, in particular for Mg, which demonstrate that not only the degree of spin polarization but also its sign can be manipulated through time delay. Since the underline physics is rather general and transparent, the presented idea may be potentially applied to nanostructures such as quantum wells and quantum dots

  19. Terahertz Focusing and Polarization Control in Large-Area Bias-Free Semiconductor Emitters

    Science.gov (United States)

    Carthy, Joanna L.; Gow, Paul C.; Berry, Sam A.; Mills, Ben; Apostolopoulos, Vasilis

    2018-03-01

    We show that, when large-area multiplex terahertz semiconductor emitters, that work on diffusion currents and Schottky potentials, are illuminated by ultrashort optical pulses they can radiate a directional electromagnetic terahertz pulse which is controlled by the angular spectrum of the incident optical beam. Using the lens that focuses the incident near-infrared pulse, we have demonstrated THz emission focusing in free space, at the same point where the optical radiation would focus. We investigated the beam waist and Gouy phase shift of the THz emission as a function of frequency. We also show that the polarization profile of the emitted THz can be tailored by the metallic patterning on the semiconductor, demonstrating radial polarization when a circular emitter design is used. Our techniques can be used for fast THz beam steering and mode control for efficiently coupling to waveguides without the need for THz lenses or parabolic mirrors.

  20. Circular polarization control for the European XFEL in the soft X-ray regime

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2011-06-01

    The possibility of producing X-ray radiation with high degree of circular polarization is an important asset at XFEL facilities. Polarization control is most important in the soft X-ray region.However, the baseline of the European XFEL, including the soft X-ray SASE3 line, foresees planar undulators only, yielding linearly-polarized radiation. It is clear that the lowest-risk strategy for implementing polarization control at SASE3 involves adding an APPLE II-type undulator at the end of the planar undulator, in order to exploit the micro bunching from the baseline FEL. Detailed experience is available in synchrotron radiation laboratories concerning the manufacturing of 5 m-long APPLE II undulators. However, the choice of a short helical radiator leads to the problem of background suppression. The driving idea of our proposal is that the background radiation can be suppressed by spatial filtering. This operation can be performed by inserting slits behind the APPLE II radiator, where the linearly-polarized radiation spot size is about 30 times larger than the radiation spot size from the helical radiator. The last 7 cells of the SASE3 undulator are left with an open gap in order to provide a total 42 m drift section for electron beam and radiation. Due to the presence of the drift the linearly-polarized radiation spot size increases, and the linearly polarized background radiation can be suppressed by the slits. At the same time, the microbunch structure is easily preserved, so that intense (100 GW) coherent radiation is emitted in the helical radiator. We propose a filtering setup consisting of a pair of water cooled slits for X-ray beam filtering and of a 5 m-long magnetic chicane, which creates an offset for slit installation immediately behind the helical radiator. Electrons and X-rays are separated before the slits by the magnetic chicane, so that the electron beam can pass by the filtering setup without perturbations. Based on start-to-end simulations we

  1. The actin cytoskeleton may control the polar distribution of an auxin transport protein

    Science.gov (United States)

    Muday, G. K.; Hu, S.; Brady, S. R.; Davies, E. (Principal Investigator)

    2000-01-01

    The gravitropic bending of plants has long been linked to the changes in the transport of the plant hormone auxin. To understand the mechanism by which gravity alters auxin movement, it is critical to know how polar auxin transport is initially established. In shoots, polar auxin transport is basipetal (i.e., from the shoot apex toward the base). It is driven by the basal localization of the auxin efflux carrier complex. One mechanism for localizing this efflux carrier complex to the basal membrane may be through attachment to the actin cytoskeleton. The efflux carrier protein complex is believed to consist of several polypeptides, including a regulatory subunit that binds auxin transport inhibitors, such as naphthylphthalamic acid (NPA). Several lines of experimentation have been used to determine if the NPA binding protein interacts with actin filaments. The NPA binding protein has been shown to partition with the actin cytoskeleton during detergent extraction. Agents that specifically alter the polymerization state of the actin cytoskeleton change the amount of NPA binding protein and actin recovered in these cytoskeletal pellets. Actin-affinity columns were prepared with polymers of actin purified from zucchini hypocotyl tissue. NPA binding activity was eluted in a single peak from the actin filament column. Cytochalasin D, which fragments the actin cytoskeleton, was shown to reduce polar auxin transport in zucchini hypocotyls. The interaction of the NPA binding protein with the actin cytoskeleton may localize it in one plane of the plasma membrane, and thereby control the polarity of auxin transport.

  2. Automated calibration and control for polarization-resolved second harmonic generation on commercial microscopes.

    Science.gov (United States)

    Romijn, Elisabeth I; Finnøy, Andreas; Kumar, Rajesh; Lilledahl, Magnus B

    2018-01-01

    Polarization-resolved second harmonic generation (P-SHG) microscopy has evolved as a promising technique to reveal subresolution information about the structure and orientation of ordered biological macromolecules. To extend the adoption of the technique, it should be easily integrated onto commercial laser scanning microscopes. Furthermore, procedures for easy calibration and assessment of measurement accuracy are essential, and measurements should be fully automated to allow for analysis of large quantities of samples. In this paper we present a setup for P-SHG which is readily incorporated on commercial multiphoton microscopes. The entire system is completely automated which allows for rapid calibration through the freely available software and for automated imaging for different polarization measurements, including linear and circular polarization of the excitation beam. The results show that calibration settings are highly system dependent. We also show that the accuracy of the polarization control is easily quantified and that it varies between systems. The accuracy can be tuned by iterative alignment of optics or a more fine-grained calibration procedure. Images of real samples show that the red accuracy of the results is easily visualized with the automated setup. Through this system we believe that P-SHG could develop a wider adoption in biomedical applications.

  3. Polarization Converter with Controllable Birefringence Based on Hybrid All-Dielectric-Graphene Metasurface

    Science.gov (United States)

    Owiti, Edgar O.; Yang, Hanning; Liu, Peng; Ominde, Calvine F.; Sun, Xiudong

    2018-02-01

    Previous studies on hybrid dielectric-graphene metasurfaces have been used to implement induced transparency devices, while exhibiting high Q-factors based on trapped magnetic resonances. Typically, the transparency windows are single wavelength and less appropriate for polarization conversion structures. In this work, a quarter-wave plate based on a hybrid silicon-graphene metasurface with controllable birefringence is numerically designed. The phenomena of trapped magnetic mode resonance and high Q-factors are modulated by inserting graphene between silicon and silica. This results in a broader transmission wavelength in comparison to the all-dielectric structure without graphene. The birefringence tunability is based on the dimensions of silicon and the Fermi energy of graphene. Consequently, a linear-to-circular polarization conversion is achieved at a high degree of 96%, in the near-infrared. Moreover, the polarization state of the scattered light is switchable between right and left hand circular polarizations, based on an external gate biasing voltage. Unlike in plasmonic metasurfaces, these achievements demonstrate an efficient structure that is free from radiative and ohmic losses. Furthermore, the ultrathin thickness and the compactness of the structure are demonstrated as key components in realizing integrable and CMOS compatible photonic sensors.

  4. High performance polarization-independent Quantum Dot Semiconductor Optical Amplifier with 22 dB fiber to fiber gain using Mode Propagation Tuning without additional polarization controller

    Science.gov (United States)

    Farmani, Ali; Farhang, Mahmoud; Sheikhi, Mohammad H.

    2017-08-01

    A detailed numerical investigation of polarization-independent quantum dot InAs/GaAs semiconductor optical amplifier (PIQS) based on a technique called mode propagation tuning (MPT) without the need for the polarization controller (PC) is reported, which can solve the limitation caused by polarization sensitivity in a semiconductor optical amplifier (SOA). Our calculations show that by a suitable tuning of the thickness of the active layer, only the TE0 and TM0 modes can propagate. Moreover, the gain saturation behavior of this SOA was measured at 1.55 μ m and found to be polarization-independent (PI). At active layer thickness of 1.7 μ m, the confinement factor was 0.75 and 0.7 for TE0 and TM0 modes, respectively, which leads to a gain difference up to 0.1 dB. The rate equations of the QD-SOA were also solved and a fiber to fiber gain of 22 dB was obtained. Additionally, a numerical simulation is presented which shows that the residual gain ripple and polarization sensitivity are sufficiently reduced when residual facet reflectivities of the SOA are in the range below 10-4 . In addition, the full-width at half-maximum of the horizontal and vertical far-field patterns (FFPs) are measured as 30° × 30°. The proposed structure can be used for logical applications.

  5. Unravelling the Franklin Mystery, Second Edition with David C. Woodman

    DEFF Research Database (Denmark)

    Burke, Danita Catherine

    2017-01-01

    This is a forthcoming book review of David C. Woodman's second edition of his book "Unravelling the Franklin Mystery."......This is a forthcoming book review of David C. Woodman's second edition of his book "Unravelling the Franklin Mystery."...

  6. Transmission Magnitude and Phase Control for Polarization-Preserving Reflectionless Metasurfaces

    Science.gov (United States)

    Kwon, Do-Hoon; Ptitcyn, Grigorii; Díaz-Rubio, Ana; Tretyakov, Sergei A.

    2018-03-01

    For transmissive applications of electromagnetic metasurfaces, an array of subwavelength Huygens' meta-atoms are typically used to eliminate reflection and achieve a high-transmission power efficiency together with a wide transmission phase coverage. We show that the underlying principle of low reflection and full control over transmission is asymmetric scattering into the specular reflection and transmission directions that results from a superposition of symmetric and antisymmetric scattering components, with Huygens' meta-atoms being one example configuration. Available for oblique illumination in TM polarization, a meta-atom configuration comprising normal and tangential electric polarizations is presented, which is capable of reflectionless, full-power transmission and a 2 π transmission phase coverage as well as full absorption. For lossy metasurfaces, we show that a complete phase coverage is still available for reflectionless designs for any value of absorptance. Numerical examples in the microwave and optical regimes are provided.

  7. Rapid Energy Transfer Enabling Control of Emission Polarization in Perylene Bisimide Donor-Acceptor Triads.

    Science.gov (United States)

    Menelaou, Christopher; ter Schiphorst, Jeroen; Kendhale, Amol M; Parkinson, Patrick; Debije, Michael G; Schenning, Albertus P H J; Herz, Laura M

    2015-04-02

    Materials showing rapid intramolecular energy transfer and polarization switching are of interest for both their fundamental photophysics and potential for use in real-world applications. Here, we report two donor-acceptor-donor triad dyes based on perylene-bisimide subunits, with the long axis of the donors arranged either parallel or perpendicular to that of the central acceptor. We observe rapid energy transfer (energy transfer rate for the linearly arranged triad but severely underestimates it for the orthogonal case. We show that the rapid energy transfer arises from a combination of through-bond coupling and through-space transfer between donor and acceptor units. As they allow energy cascading to an excited state with controllable polarization, these triad dyes show high potential for use in luminescent solar concentrator devices.

  8. Interface between astrophysical datasets and distributed database management systems (DAVID)

    Science.gov (United States)

    Iyengar, S. S.

    1988-01-01

    This is a status report on the progress of the DAVID (Distributed Access View Integrated Database Management System) project being carried out at Louisiana State University, Baton Rouge, Louisiana. The objective is to implement an interface between Astrophysical datasets and DAVID. Discussed are design details and implementation specifics between DAVID and astrophysical datasets.

  9. David's Dying Directives according to Josephus

    Directory of Open Access Journals (Sweden)

    Begg, Christopher

    2005-12-01

    Full Text Available 1 Kgs 2,1-9, «the testament of David», records the king's final instructions to his son Solomon. This article offers a detailed study of Josephus' version (Ant. 7.383- 388 of the testament in relation to its biblical source. The study focusses particularly on the textual affinities of Josephus' presentation, given the differences among the various ancient versions (MT, LXX, Targum of the testament. The article likewise examines the range of re-writing techniques utilized by Josephus in Ant. 7.383-388 and their contribution in generating a distinctive rendition of David's testament.

    1 Re 2,1-9, «el testamento de David», recoge las últimas instrucciones del rey para su hijo Salomón. Este artículo ofrece un detallado estudio de la versión de Josefo (Ant. 7.383-388 del testamento en relación con su fuente bíblica. El estudio se centra especialmente en las afinidades textuales de la presentación de Josefo, a la vista de las diferencias entre las distintas versiones antiguas del testamento (TM, LXX, Targum. Así mismo, el artículo examina las diferentes técnicas de reescritura empleadas por Josefo en Ant. 7.383-388 y su contribución a la producción de una versión diferenciada del testamento de David.

  10. Control software of a variably polarizing undulator (APPLE type) for SX beamline in the SPring-8

    International Nuclear Information System (INIS)

    Hiramatsu, Yoichi; Shimada, Taihei; Miyahara, Yoshikazu

    1999-12-01

    This paper describes the control software of a variably polarizing undulator (APPLE Type) that was installed at the SX beamline (cell number 23) in the SPring-8 storage ring in February, 1998. This undulator produces a polarized radiation in the energy range of soft X-ray by changing the gap distance between two pairs of permanent magnet arrays (gap movement). The main characteristic of the undulator is a capability to generate right and left circular polarization alternately at a period of 2 sec (0.5 Hz) by high speed phase-shifting (periodic phase movement). The developed software makes a fast correction of the closed orbit distortion (COD) of an electron beam by exciting steering magnets at a rate of time interval of 24 msec (42 Hz) during the movement of magnet arrays. Also, the software is capable to put these magnet arrays into a constant periodic phase movement with an error less than 0.1% for the period of 2 sec. The software was developed in accordance with the directions of SPring-8 standard for software development. (author)

  11. Spontaneous cell polarization: Feedback control of Cdc42 GTPase breaks cellular symmetry.

    Science.gov (United States)

    Martin, Sophie G

    2015-11-01

    Spontaneous polarization without spatial cues, or symmetry breaking, is a fundamental problem of spatial organization in biological systems. This question has been extensively studied using yeast models, which revealed the central role of the small GTPase switch Cdc42. Active Cdc42-GTP forms a coherent patch at the cell cortex, thought to result from amplification of a small initial stochastic inhomogeneity through positive feedback mechanisms, which induces cell polarization. Here, I review and discuss the mechanisms of Cdc42 activity self-amplification and dynamic turnover. A robust Cdc42 patch is formed through the combined effects of Cdc42 activity promoting its own activation and active Cdc42-GTP displaying reduced membrane detachment and lateral diffusion compared to inactive Cdc42-GDP. I argue the role of the actin cytoskeleton in symmetry breaking is not primarily to transport Cdc42 to the active site. Finally, negative feedback and competition mechanisms serve to control the number of polarization sites. © 2015 WILEY Periodicals, Inc.

  12. The cell polarity determinant CDC42 controls division symmetry to block leukemia cell differentiation.

    Science.gov (United States)

    Mizukawa, Benjamin; O'Brien, Eric; Moreira, Daniel C; Wunderlich, Mark; Hochstetler, Cindy L; Duan, Xin; Liu, Wei; Orr, Emily; Grimes, H Leighton; Mulloy, James C; Zheng, Yi

    2017-09-14

    As a central regulator of cell polarity, the activity of CDC42 GTPase is tightly controlled in maintaining normal hematopoietic stem and progenitor cell (HSC/P) functions. We found that transformation of HSC/P to acute myeloid leukemia (AML) is associated with increased CDC42 expression and activity in leukemia cells. In a mouse model of AML, the loss of Cdc42 abrogates MLL-AF9 -induced AML development. Furthermore, genetic ablation of CDC42 in both murine and human MLL-AF9 (MA9) cells decreased survival and induced differentiation of the clonogenic leukemia-initiating cells. We show that MLL-AF9 leukemia cells maintain cell polarity in the context of elevated Cdc42-guanosine triphosphate activity, similar to nonmalignant, young HSC/Ps. The loss of Cdc42 resulted in a shift to depolarized AML cells that is associated with a decrease in the frequency of symmetric and asymmetric cell divisions producing daughter cells capable of self-renewal. Importantly, we demonstrate that inducible CDC42 suppression in primary human AML cells blocks leukemia progression in a xenograft model. Thus, CDC42 loss suppresses AML cell polarity and division asymmetry, and CDC42 constitutes a useful target to alter leukemia-initiating cell fate for differentiation therapy. © 2017 by The American Society of Hematology.

  13. Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

    International Nuclear Information System (INIS)

    Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

    2015-01-01

    We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

  14. Tunable and switchable multi-wavelength erbium-doped fiber laser with highly nonlinear photonic crystal fiber and polarization controllers

    International Nuclear Information System (INIS)

    Liu, X M; Lin, A; Zhao, W; Lu, K Q; Wang, Y S; Zhang, T Y; Chung, Y

    2008-01-01

    We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature

  15. All dielectric reflective metasurface for controlling phase and polarization by using silicon nanoblocks

    Science.gov (United States)

    Kim, Youngsoo; Lee, Young Jin; Hong, Seokhyeun; Moon, Kihwan; Kwon, Soon-Hong

    2017-09-01

    We suggest all dielectric metasurfaces composed of silicon (Si) nanoblock array. We can control the phase and polarization of light reflected the metasurface by changing Mie scattering of each Si block. The Mie scattering is easily adjusted by changing structure parameters of Si block width and height. In single Si nanoblock, the magnetic dipole resonance mode was diminished when decreasing its height. In this study, for making 2-dimensional metasurface, we analyze the scattering cross-section by changing width and height of Si nanoblock with finite-difference time-domain method.

  16. Convex and concave micro-structured silicone controls the shape, but not the polarization state of human macrophages.

    Science.gov (United States)

    Malheiro, V; Lehner, F; Dinca, V; Hoffmann, P; Maniura-Weber, K

    2016-10-18

    The typical foreign body response (FBR) to synthetic implants is characterized by local inflammation and tissue fibrosis. Silicone implants have been associated with the development of adverse capsular contraction (ACC); a form of excessive FBR to the material that often requires the replacement of the implant. It has been shown that surface roughening of silicone can reduce the prevalence of ACC, but the mechanisms remain poorly understood. Macrophages are key cells in FBR. They exert their control mainly by polarizing into pro-inflammatory (M1) or pro-healing (M2) cells. It is postulated that surface topography can reduce M1 polarization by limiting cell spreading and cytoskeleton organization. To test this hypothesis, we used KrF Excimer laser ablation with half-tone masks to produce convex and concave topographies with controlled surface dimensional parameters. Cells in convex and concave topographies were compared to cells in planar surfaces, with or without chemical polarization. We show that chemical polarization induced specific changes in the cell shape on planar substrates. Macrophage shape and size was different in concave and convex surfaces, but no correlation was found with the cell polarization state. The results highlight that chemical polarization of macrophages is associated with changes in the cell shape; however, topography-induced changes in macrophage shape could not be linked with a shift in macrophage polarization. Thus, the sole manipulation of cell shape does not seem to be the mechanism by which macrophage function could be controlled.

  17. Active polarization control of a 1.43 kW narrow linewidth fiber amplifier based on SPGD algorithm

    Science.gov (United States)

    Su, Rongtao; Liu, Yakun; Yang, Baolai; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Xu, Xiaojun

    2017-04-01

    Active polarization control of a high power fiber amplifier has been demonstrated. The master oscillator power amplifier system consisted of a narrow linewidth laser seed and a three-stage Yb-fiber amplifier. The narrow linewidth laser seed was generated by phase modulating a single frequency fiber laser using a white noise source. Maximum power of 1437 W was obtained from the main amplifier, which was limited by the available pump power. When the polarization state of the narrow linewidth (∼0.17 nm) laser was actively controlled by using a polarization controller based on stochastic parallel gradient descent algorithm, the polarization extinction ratio of the laser beam was more than 11.1 dB at the maximum output power.

  18. Diacylglycerol Kinases: Shaping Diacylglycerol and Phosphatidic Acid Gradients to Control Cell Polarity

    Directory of Open Access Journals (Sweden)

    Gianluca Baldanzi

    2016-11-01

    Full Text Available Diacylglycerol kinases (DGKs terminate diacylglycerol (DAG signaling and promote phosphatidic acid (PA production. Isoform specific regulation of DGKs activity and localization allows DGKs to shape the DAG and PA gradients. The capacity of DGKs to constrain the areas of DAG signaling is exemplified by their role in defining the contact interface between T cells and antigen presenting cells: the immune synapse. Upon T cell receptor engagement, both DGK α and ζ metabolize DAG at the immune synapse thus constraining DAG signaling. Interestingly, their activity and localization are not fully redundant because DGKζ activity metabolizes the bulk of DAG in the cell, whereas DGKα limits the DAG signaling area localizing specifically at the periphery of the immune synapse.When DGKs terminate DAG signaling, the local PA production defines a new signaling domain, where PA recruits and activates a second wave of effector proteins. The best-characterized example is the role of DGKs in protrusion elongation and cell migration. Indeed, upon growth factor stimulation, several DGK isoforms, such as α, ζ, and γ, are recruited and activated at the plasma membrane. Here, local PA production controls cell migration by finely modulating cytoskeletal remodeling and integrin recycling. Interestingly, DGK-produced PA also controls the localization and activity of key players in cell polarity such as aPKC, Par3, and integrin β1. Thus, T cell polarization and directional migration may be just two instances of the general contribution of DGKs to the definition of cell polarity by local specification of membrane identity signaling.

  19. Laser polarization dependent and magnetically control of group velocity in a dielectric medium doped with nanodiamond nitrogen vacancy centers

    Energy Technology Data Exchange (ETDEWEB)

    Asadpour, Seyyed Hossein; Rahimpour Soleimani, H., E-mail: Rahimpour@guilan.ac.ir

    2014-03-01

    In this paper, group velocity control of Gaussian beam in a dielectric medium doped with nanodiamond nitrogen vacancy (NV) centers under optical excitation is discussed. The shape of transmitted and reflected pulses from dielectric can be tuned by changing the intensity of magnetic field and polarization of the control beam. The effect of intensity of control beam on group velocity is also investigated.

  20. Polarity, cell division, and out-of-equilibrium dynamics control the growth of epithelial structures

    Science.gov (United States)

    Cerruti, Benedetta; Puliafito, Alberto; Shewan, Annette M.; Yu, Wei; Combes, Alexander N.; Little, Melissa H.; Chianale, Federica; Primo, Luca; Serini, Guido; Mostov, Keith E.; Celani, Antonio

    2013-01-01

    The growth of a well-formed epithelial structure is governed by mechanical constraints, cellular apico-basal polarity, and spatially controlled cell division. Here we compared the predictions of a mathematical model of epithelial growth with the morphological analysis of 3D epithelial structures. In both in vitro cyst models and in developing epithelial structures in vivo, epithelial growth could take place close to or far from mechanical equilibrium, and was determined by the hierarchy of time-scales of cell division, cell–cell rearrangements, and lumen dynamics. Equilibrium properties could be inferred by the analysis of cell–cell contact topologies, and the nonequilibrium phenotype was altered by inhibiting ROCK activity. The occurrence of an aberrant multilumen phenotype was linked to fast nonequilibrium growth, even when geometric control of cell division was correctly enforced. We predicted and verified experimentally that slowing down cell division partially rescued a multilumen phenotype induced by altered polarity. These results improve our understanding of the development of epithelial organs and, ultimately, of carcinogenesis. PMID:24145168

  1. Subject in Tractatus according to David Pears

    Directory of Open Access Journals (Sweden)

    M Hoseinzadeh Yazdi

    2013-03-01

    Considering the centrality of subjectivism in modern philosophy, this article attempts to explain subject in Tractatus according to David Pears. A review of Wittgenstein’s earlier teachings reveals that he considers a fundamental limitation for language. The subject serves as a point of view from which the language can be understood. The subject is the presupposition of understanding. Another way of putting this would be to say that any experience is understood from a point of view which is not represented in that experience. Regarding this, it seems that earlier Wittgenstein is somehow subjectivist. This specific form of subjectivism is different from Kantian subjectivism.

  2. David Maljković. Riflessioni sulla memoria

    Directory of Open Access Journals (Sweden)

    Valentina Rossi

    2013-12-01

    Full Text Available Si analizza il lavoro dell'artista croato David Maljković (Rijeka 1973- che ha continuato a tessere relazioni con il passato, non solo del proprio paese ma anche con la memoria storica e artistica dell'Italia. A partire dalla mostra Italia Italie Italien Italy Whocky (2008, le ricerche che legano l'artista al nostro paese si sono intensificate fino ad arrivare alla sua prima personale in un museo italiano, Sources in the Air (ottobre 2013 presso la GAMeC di Bergamo.

  3. David Ferrier: brain drawings and brain maps.

    Science.gov (United States)

    Lazar, J Wayne

    2013-01-01

    This chapter has two emphases, one is about the men who influenced the visual representations that David Ferrier (1843-1928) used to illustrate his work on localization of brain functions during the years 1873-1875, namely, Alexander Ecker, John C. Galton, and Ernest Waterlow, and the other is about the nature of medical representations and of Ferrier's illustrations in particular. Medical illustrations are characterized either as pictures, line drawings, or brain maps. Ferrier's illustrations will be shown to be increasingly sophisticated brain maps that contrast with early nineteenth-century standards of medical illustrations, as exemplified by John Bell (1763-1829). © 2013 Elsevier B.V. All rights reserved.

  4. David W. Krogmann, 1931-2016.

    Science.gov (United States)

    Brand, Jerry J; Kerfeld, Cheryl A; Cramer, William A; Govindjee

    2017-04-01

    We provide here reflections on the life and career of David W. Krogmann (1931-2016), a great scientist, a mentor and an outstanding teacher, who had a remarkable impact on anyone who came in contact with him. Dave was a pillar of photosynthesis at Purdue University, and an international authority on electron transfer intermediates in oxygenic photosynthesis, particularly the soluble cytochromes. The photosynthetic system of his choice was cyanobacteria, and one of his major discoveries was the Orange Carotenoid Protein in these microrganisms.

  5. David Hume: Dios y el hecho religioso

    Directory of Open Access Journals (Sweden)

    Iñaki Oneca Agurruza

    2003-12-01

    Full Text Available El objeto del presente estudio es ahondar en la concepción religiosa de David Hume y en su idea de Dios, así como profundizar en este interesante pilar de su estructura filosófico-empírica. El contexto histórico-filosófico en el cual este autor investigó sobre dicho tema, así como las diferentes visiones del mencionado objeto de estudio, serán, por tanto, tenidas en suficiente consideración.

  6. Muscle Stem Cell Fate Is Controlled by the Cell-Polarity Protein Scrib

    Directory of Open Access Journals (Sweden)

    Yusuke Ono

    2015-02-01

    Full Text Available Satellite cells are resident skeletal muscle stem cells that supply myonuclei for homeostasis, hypertrophy, and repair in adult muscle. Scrib is one of the major cell-polarity proteins, acting as a potent tumor suppressor in epithelial cells. Here, we show that Scrib also controls satellite-cell-fate decisions in adult mice. Scrib is undetectable in quiescent cells but becomes expressed during activation. Scrib is asymmetrically distributed in dividing daughter cells, with robust accumulation in cells committed to myogenic differentiation. Low Scrib expression is associated with the proliferative state and preventing self-renewal, whereas high Scrib levels reduce satellite cell proliferation. Satellite-cell-specific knockout of Scrib in mice causes a drastic and insurmountable defect in muscle regeneration. Thus, Scrib is a regulator of tissue stem cells, controlling population expansion and self-renewal with Scrib expression dynamics directing satellite cell fate.

  7. Optical reconfiguration and polarization control in semi-continuous gold films close to the percolation threshold

    DEFF Research Database (Denmark)

    Frydendahl, Christian; Repän, Taavi; Geisler, Mathias

    2017-01-01

    Controlling and confining light by exciting plasmons in resonant metallic nanostructures is an essential aspect of many new emerging optical technologies. Here we explore the possibility of controllably reconfiguring the intrinsic optical properties of semi-continuous gold films, by inducing...... permanent morphological changes with a femtosecond (fs)-pulsed laser above a critical power. Optical transmission spectroscopy measurements show a correlation between the spectra of the morphologically modified films and the wavelength, polarization, and the intensity of the laser used for alteration....... In order to understand the modifications induced by the laser writing, we explore the near-field properties of these films with electron energy-loss spectroscopy (EELS). A comparison between our experimental data and full-wave simulations on the exact film morphologies hints toward a restructuring...

  8. Flat polarization-controlled cylindrical lens based on the Pancharatnam-Berry geometric phase

    Science.gov (United States)

    Piccirillo, Bruno; Florinda Picardi, Michela; Marrucci, Lorenzo; Santamato, Enrico

    2017-05-01

    The working principle of ordinary refractive lenses can be explained in terms of the space-variant optical phase retardations they introduce, which reshape the optical wavefront curvature and hence affect the subsequent light propagation. These phases, in turn, are due to the varying optical path length followed by light at different transverse positions relative to the lens center. A similar lensing behavior can, however, be obtained when the optical phases are introduced by an entirely different mechanism. Here, we consider the ‘geometric phases’ that arise from the polarization transformations occurring in anisotropic optical media, named after Pancharatnam and Berry. The medium anisotropy axis is taken to be space-variant in the transverse plane and the resulting varying geometric phases give rise to the wavefront reshaping and lensing effect, which however also depends on the input polarization. We describe the realization and characterization of a cylindrical geometric-phase lens that is converging for a given input circular-polarization state and diverging for the orthogonal one, which provides one of the simplest possible examples of optical elements based on geometric phases. The demonstrated lens is flat and only a few microns thick (not including the supporting substrates); moreover, its working wavelength can be tuned and the lensing can be switched on and off by the action of an external control electric field. Other kinds of lenses or more general phase elements inducing different wavefront distortions can be obtained by a similar approach. Besides their potential for optoelectronic technology, these devices offer good opportunities for introducing college-level students to an advanced topic of modern physics, such as the Berry phase, with the help of interesting optical demonstrations.

  9. Dual Color Plasmonic Pixels Create a Polarization Controlled Nano Color Palette.

    Science.gov (United States)

    Li, Zhibo; Clark, Alasdair W; Cooper, Jonathan M

    2016-01-26

    Color filters based upon nanostructured metals have garnered significant interest in recent years, having been positioned as alternatives to the organic dye-based filters which provide color selectivity in image sensors, as nonfading "printing" technologies for producing images with nanometer pixel resolution, and as ultra-high-resolution, small foot-print optical storage and encoding solutions. Here, we demonstrate a plasmonic filter set with polarization-switchable color properties, based upon arrays of asymmetric cross-shaped nanoapertures in an aluminum thin-film. Acting as individual color-emitting nanopixels, the plasmonic cavity-apertures have dual-color selectivity, transmitting one of two visible colors, controlled by the polarization of the white light incident on the rear of the pixel and tuned by varying the critical dimensions of the geometry and periodicity of the array. This structural approach to switchable optical filtering enables a single nanoaperture to encode two information states within the same physical nanoaperture, an attribute we use here to create micro image displays containing duality in their optical information states.

  10. Domain-specific control of germ cell polarity and migration by multifunction Tre1 GPCR

    Science.gov (United States)

    2017-01-01

    The migration of primordial germ cells (PGCs) from their place of origin to the embryonic gonad is an essential reproductive feature in many animal species. In Drosophila melanogaster, a single G protein–coupled receptor, Trapped in endoderm 1 (Tre1), mediates germ cell polarization at the onset of active migration and directs subsequent migration of PGCs through the midgut primordium. How these different aspects of cell behavior are coordinated through a single receptor is not known. We demonstrate that two highly conserved domains, the E/N/DRY and NPxxY motifs, have overlapping and unique functions in Tre1. The Tre1-NRY domain via G protein signaling is required for reading and responding to guidance and survival cues controlled by the lipid phosphate phosphatases Wunen and Wunen2. In contrast, the Tre1-NPIIY domain has a separate role in Rho1- and E-cadherin–mediated polarization at the initiation stage independent of G protein signaling. We propose that this bifurcation of the Tre1 G protein–coupled receptor signaling response via G protein–dependent and independent branches enables distinct spatiotemporal regulation of germ cell migration. PMID:28687666

  11. The RPG gene of Medicago truncatula controls Rhizobium-directed polar growth during infection.

    Science.gov (United States)

    Arrighi, Jean-François; Godfroy, Olivier; de Billy, Françoise; Saurat, Olivier; Jauneau, Alain; Gough, Clare

    2008-07-15

    Rhizobia can infect roots of host legume plants and induce new organs called nodules, in which they fix atmospheric nitrogen. Infection generally starts with root hair curling, then proceeds inside newly formed, intracellular tubular structures called infection threads. A successful symbiotic interaction relies on infection threads advancing rapidly at their tips by polar growth through successive cell layers of the root toward developing nodule primordia. To identify a plant component that controls this tip growth process, we characterized a symbiotic mutant of Medicago truncatula, called rpg for rhizobium-directed polar growth. In this mutant, nitrogen-fixing nodules were rarely formed due to abnormally thick and slowly progressing infection threads. Root hair curling was also abnormal, indicating that the RPG gene fulfils an essential function in the process whereby rhizobia manage to dominate the process of induced tip growth for root hair infection. Map-based cloning of RPG revealed a member of a previously unknown plant-specific gene family encoding putative long coiled-coil proteins we have called RRPs (RPG-related proteins) and characterized by an "RRP domain" specific to this family. RPG expression was strongly associated with rhizobial infection, and the RPG protein showed a nuclear localization, indicating that this symbiotic gene constitutes an important component of symbiotic signaling.

  12. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    International Nuclear Information System (INIS)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-01-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ( 13 C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B o ), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of 13 C based endogenous contrast agents used in molecular imaging

  13. LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

    Science.gov (United States)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ((13)C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of (13)C based endogenous contrast agents used in molecular imaging.

  14. A Polar Fuzzy Control Scheme for Hybrid Power System Using Vehicle-To-Grid Technique

    Directory of Open Access Journals (Sweden)

    Mohammed Elsayed Lotfy

    2017-07-01

    Full Text Available A novel polar fuzzy (PF control approach for a hybrid power system is proposed in this research. The proposed control scheme remedies the issues of system frequency and the continuity of demand supply caused by renewable sources’ uncertainties. The hybrid power system consists of a wind turbine generator (WTG, solar photovoltaics (PV, a solar thermal power generator (STPG, a diesel engine generator (DEG, an aqua-electrolyzer (AE, an ultra-capacitor (UC, a fuel-cell (FC, and a flywheel (FW. Furthermore, due to the high cost of the battery energy storage system (BESS, a new idea of vehicle-to-grid (V2G control is applied to use the battery of the electric vehicle (EV as equivalent to large-scale energy storage units instead of small batteries to improve the frequency stability of the system. In addition, EV customers’ convenience is taken into account. A minimal-order observer is used to estimate the supply error. Then, the area control error (ACE signal is calculated in terms of the estimated supply error and the frequency deviation. ACE is considered in the frequency domain. Two PF approaches are utilized in the intended system. The mission of each controller is to mitigate one frequency component of ACE. The responsibility for ACE compensation is shared among all parts of the system according to their speed of response. The performance of the proposed control scheme is compared to the conventional fuzzy logic control (FLC. The effectiveness and robustness of the proposed control technique are verified by numerical simulations under various scenarios.

  15. Coherent optical control of the ultrafast dephasing and mobility in a polar semiconductor

    Science.gov (United States)

    Lee, J. D.; Gomi, H.; Hase, Muneaki

    2009-10-01

    Using the nonperturbative many-body time-dependent approach, we investigate the nonequilibrium dynamics of the coherent longitudinal optical phonon-plasmon coupled (LOPC) modes in a polar semiconductor and explore their coherent optical control and eventually the carrier mobility of the semiconductor. The basic idea for a control of the carrier mobility is to manipulate the ultrafast dephasing of the coherent carrier-relevant LOPC mode. We theoretically propose two possible options to realize the idea and reach the final goal. One is to optimize a semiconductor by finely balancing two kinds of carrier densities by chemical doping and optical doping (or photodoping), where the relaxation of the coherent carrier-relevant LOPC mode would respond in a (weak) singular way. It is found that, in this way, the carrier mobility could be enhanced by a few tens of percent. The other is to optimize the optical pumping laser. In this option, the pulse train creating pure virtual carriers through the below-band-gap excitation would be incorporated for an optical pumping, which can make possible the dephasing-free dynamics of the coherent carrier-relevant LOPC mode. The carrier mobility can then be efficiently controlled and dramatically enhanced by synchronizing the pulse train with its coherent oscillation. This might imply one of ultimate ways to control the carrier mobility of the semiconductor.

  16. Harmonic Mitigation Using a Polarized Ramp-time Current-Controlled Inverter

    Directory of Open Access Journals (Sweden)

    Lawrence J. Borle

    2010-12-01

    Full Text Available This paper describes the implementation of a shunt active power filter for a three-phase four-wire system to compensate for power quality problems generated by mixed non-linear loads, which are a combination of harmonic, reactive and unbalanced components. The filter is a three-phase current-controlled voltage source inverter (CC-VSI with a filter inductor at the AC output and a DC-bus capacitor. The CC-VSI is operated to directly control the grid current to be sinusoidal and in phase with the grid voltage without sensing the load currents. The switching is controlled using polarized ramp-time current control, which is based on the concept of zero average current error (ZACE with a fixed switching frequency. The laboratory experiment results indicate that the filter is able to mitigate predominantly the harmonics, as well as the reactive power, so that the grid currents are sinusoidal, in phase with the grid voltages and symmetrical although the grid voltage contains harmonics.

  17. Don Davide Albertario propagandista antiebraico. L'accusa di omicidio rituale

    Directory of Open Access Journals (Sweden)

    Annalisa Di Fant

    2011-05-01

    Full Text Available The article analyses the leading role played by the priest/journalist Davide Albertario in the catholic antisemite propaganda of the late 19th century. He was director of "L'Osservatore Cattolico", a Milan-based daily paper belonging to the catholic press network controlled by the Vatican, that published many articles against the Jews, notably involving the blood libel.

  18. Subject in Tractatus according to David Pears

    Directory of Open Access Journals (Sweden)

    M Hoseinzadeh Yazdi

    2013-02-01

    Full Text Available Subjectivism is viewed as one of the most fundamental underpinnings of modern philosophy. In modern philosophy, subject takes up a new position in human knowledge. The formation of the concept of subject is a decisive turn with which the modern philosophy starts. Considering the centrality of subjectivism in modern philosophy, this article attempts to explain subject in Tractatus according to David Pears. A review of Wittgenstein’s earlier teachings reveals that he considers a fundamental limitation for language. The subject serves as a point of view from which the language can be understood. The subject is the presupposition of understanding. Another way of putting this would be to say that any experience is understood from a point of view which is not represented in that experience. Regarding this, it seems that earlier Wittgenstein is somehow subjectivist. This specific form of subjectivism is different from Kantian subjectivism.

  19. David L. Rosenhan (1929-2012).

    Science.gov (United States)

    Ross, Lee; Kavanagh, David

    2013-09-01

    Presents an obituary for David L. Rosenhan (1929-2012). A distinguished psychologist and professor emeritus at Stanford University, Rosenhan died February 6, 2012, at the age of 82, after a long illness. Born in Jersey City, New Jersey, on November 22, 1929, he received a bachelor's degree in mathematics (1951) from Yeshiva College and a master's degree in economics (1953) and a doctorate in psychology (1958) from Columbia University. A professor of law and of psychology at Stanford University from 1971 until his retirement in 1998, Rosenhan was a pioneer in applying psychological methods to the practice of law, including the examination of expert witnesses, jury selection, and jury deliberation. A former president of the American Psychology-Law Society and of the American Board of Forensic Psychology, Rosenhan was a fellow of the American Association for the Advancement of Science, of the American Psychological Association, and of the American Psychological Society. Before joining the Stanford Law School faculty, he was a member of the faculties of Swarthmore College, Princeton University, Haverford College, and the University of Pennsylvania. He also served as a research psychologist at the Educational Testing Service. As generations of Stanford students can attest, David Rosenhan was a spellbinding lecturer who managed to convey the sense that he was speaking to each individual, no matter how large the group. To his graduate students, he was consistently encouraging and optimistic, always ready to share a joke or story, and gently encouraging of their creativity and progressive independence as researchers. The lessons he cared most about offering, in the classroom as in his research, were about human dignity and the need to confront abuse of power and human frailties. © 2013 APA, all rights reserved.

  20. Polarization control of high order harmonics in the EUV photon energy range.

    Science.gov (United States)

    Vodungbo, Boris; Barszczak Sardinha, Anna; Gautier, Julien; Lambert, Guillaume; Valentin, Constance; Lozano, Magali; Iaquaniello, Grégory; Delmotte, Franck; Sebban, Stéphane; Lüning, Jan; Zeitoun, Philippe

    2011-02-28

    We report the generation of circularly polarized high order harmonics in the extreme ultraviolet range (18-27 nm) from a linearly polarized infrared laser (40 fs, 0.25 TW) focused into a neon filled gas cell. To circularly polarize the initially linearly polarized harmonics we have implemented a four-reflector phase-shifter. Fully circularly polarized radiation has been obtained with an efficiency of a few percents, thus being significantly more efficient than currently demonstrated direct generation of elliptically polarized harmonics. This demonstration opens up new experimental capabilities based on high order harmonics, for example, in biology and materials science. The inherent femtosecond time resolution of high order harmonic generating table top laser sources renders these an ideal tool for the investigation of ultrafast magnetization dynamics now that the magnetic circular dichroism at the absorption M-edges of transition metals can be exploited.

  1. Do Père David's deer lose memories of their ancestral predators?

    Science.gov (United States)

    Li, Chunwang; Yang, Xiaobo; Ding, Yuhua; Zhang, Linyuan; Fang, Hongxia; Tang, Songhua; Jiang, Zhigang

    2011-01-01

    Whether prey retains antipredator behavior after a long period of predator relaxation is an important question in predator-prey evolution. Père David's deer have been raised in enclosures for more than 1200 years and this isolation provides an opportunity to study whether Père David's deer still respond to the cues of their ancestral predators or to novel predators. We played back the sounds of crows (familiar sound) and domestic dogs (familiar non-predators), of tigers and wolves (ancestral predators), and of lions (potential naïve predator) to Père David's deer in paddocks, and blank sounds to the control group, and videoed the behavior of the deer during the experiment. We also showed life-size photo models of dog, leopard, bear, tiger, wolf, and lion to the deer and video taped their responses after seeing these models. Père David's deer stared at and approached the hidden loudspeaker when they heard the roars of tiger or lion. The deer listened to tiger roars longer, approached to tiger roars more and spent more time staring at the tiger model. The stags were also found to forage less in the trials of tiger roars than that of other sound playbacks. Additionally, it took longer for the deer to restore their normal behavior after they heard tiger roars, which was longer than that after the trial of other sound playbacks. Moreover, the deer were only found to walk away after hearing the sounds of tiger and wolf. Therefore, the tiger was probably the main predator for Père David's deer in ancient time. Our study implies that Père David's deer still retain the memories of the acoustic and visual cues of their ancestral predators in spite of the long term isolation from natural habitat.

  2. Do Père David's deer lose memories of their ancestral predators?

    Directory of Open Access Journals (Sweden)

    Chunwang Li

    Full Text Available Whether prey retains antipredator behavior after a long period of predator relaxation is an important question in predator-prey evolution. Père David's deer have been raised in enclosures for more than 1200 years and this isolation provides an opportunity to study whether Père David's deer still respond to the cues of their ancestral predators or to novel predators. We played back the sounds of crows (familiar sound and domestic dogs (familiar non-predators, of tigers and wolves (ancestral predators, and of lions (potential naïve predator to Père David's deer in paddocks, and blank sounds to the control group, and videoed the behavior of the deer during the experiment. We also showed life-size photo models of dog, leopard, bear, tiger, wolf, and lion to the deer and video taped their responses after seeing these models. Père David's deer stared at and approached the hidden loudspeaker when they heard the roars of tiger or lion. The deer listened to tiger roars longer, approached to tiger roars more and spent more time staring at the tiger model. The stags were also found to forage less in the trials of tiger roars than that of other sound playbacks. Additionally, it took longer for the deer to restore their normal behavior after they heard tiger roars, which was longer than that after the trial of other sound playbacks. Moreover, the deer were only found to walk away after hearing the sounds of tiger and wolf. Therefore, the tiger was probably the main predator for Père David's deer in ancient time. Our study implies that Père David's deer still retain the memories of the acoustic and visual cues of their ancestral predators in spite of the long term isolation from natural habitat.

  3. Organic Field Effect Transistors with Dipole-Polarized Polymer Gate Dielectrics for Control of Threshold Voltage

    OpenAIRE

    Sakai, Heisuke; Takahashi, Yoshikazu; Murata, Hideyuki

    2007-01-01

    The authors demonstrate organic field effect transistors (OFETs) with a dipole-polarized polyurea for the gate dielectrics. In the dielectrics, the internal electric field induces the mobile charge carrier in the semiconductor layer to the semiconductor-dielectric interface. OFETs with dipole-polarized gate dielectrics exhibit lower threshold voltage. With nonpolarized gate dielectrics, the threshold voltage was -11.4 V, whereas that decreased to -5.3 V with polarized gate dielectrics. In a...

  4. Electrically controlled phases of partially polarized light and orientational Kerr effect in liquid crystal ferroelectrics

    Science.gov (United States)

    Kiselev, Alexei D.; Kesaev, Vladimir V.; Pozhidaev, Evgeny P.

    2017-10-01

    We study the electro-optic properties of subwavelength-pitch deformed-helix ferroelectric liquid crystals illuminated with partially polarized light. In an experimental setup based on the Mach-Zehnder interferometer, it is found that the interference pattern crucially depends on the degree of polarization of the incident light. We evaluate the electric field dependence of both the Pancharatnam relative phase and the geometric phase for the general case of nonunitarily evolving mixed polarization states.

  5. Venemaa - lähedane ja kauge / David Vseviov

    Index Scriptorium Estoniae

    Vseviov, David, 1949-

    2007-01-01

    Rmt.: Sergejev, Vladimir ; Vseviov, David. Venemaa - lähedane ja kauge : aegade algusest kuni Vassili III-ni. Tallinn : Valgus, 2002 ; Sergejev, Vladimir ; Vseviov, David. Venemaa - lähedane ja kauge : vürstiriigist tsaaririigiks. Ivan IV. Tallinn : Valgus, 2007.

  6. Correspondentie David van Dantzig-Gerrit Mannoury : historische notitie SEN

    NARCIS (Netherlands)

    J. Siegenbeek van Heukelom; G. Alberts (Gerard)

    2000-01-01

    textabstractCorrespondence David van Dantzig--Gerrit Mannoury October 23rd 1917, after the second lecture in a course on analytical geometry David van Dantzig, student of chemistry, wrote a long letter to the professor of mathematics Gerrit Mannoury. It proved the starting point of a life-long

  7. Obituary: David L. Band (1957-2009)

    Science.gov (United States)

    Cominsky, Lynn

    2011-12-01

    David L. Band, of Potomac Maryland, died on March 16, 2009 succumbing to a long battle with spinal cord cancer. His death at the age of 52 came as a shock to his many friends and colleagues in the physics and astronomy community. Band showed an early interest and exceptional aptitude for physics, leading to his acceptance at the Massachusetts Institute of Technology as an undergraduate student in 1975. After graduating from MIT with an undergraduate degree in Physics, Band continued as a graduate student in Physics at Harvard University. His emerging interest in Astrophysics led him to the Astronomy Department at the Harvard Smithsonian Center for Astrophysics (CfA), where he did his dissertation work with Jonathan Grindlay. His dissertation (1985) entitled "Non-thermal Radiation Mechanisms and Processes in SS433 and Active Galactic Nuclei" was "pioneering work on the physics of jets arising from black holes and models for their emission, including self-absorption, which previewed much to come, and even David's own later work on Gamma-ray Bursts," according to Grindlay who remained a personal friend and colleague of Band's. Following graduate school, Band held postdoctoral positions at the Lawrence Livermore Laboratory, the University of California at Berkeley and the Center for Astronomy and Space Sciences at the University of California San Diego where he worked on the BATSE experiment that was part of the Compton Gamma Ray Observatory (CGRO), launched in 1991. BATSE had as its main objective the study of cosmic gamma-ray bursts (GRBs) and made significant advances in this area of research. Band became a world-renowned figure in the emerging field of GRB studies. He is best known for his widely-used analytic form of gamma-ray burst spectra known as the "Band Function." After the CGRO mission ended, Band moved to the Los Alamos National Laboratory where he worked mainly on classified research but continued to work on GRB energetics and spectra. When NASA planned

  8. EGFR signalling controls cellular fate and pancreatic organogenesis by regulating apicobasal polarity

    DEFF Research Database (Denmark)

    Löf-Öhlin, Zarah M; Nyeng, Pia; Bechard, Matthew E

    2017-01-01

    Apicobasal polarity is known to affect epithelial morphogenesis and cell differentiation, but it remains unknown how these processes are mechanistically orchestrated. We find that ligand-specific EGFR signalling via PI(3)K and Rac1 autonomously modulates apicobasal polarity to enforce...

  9. Arbitrary Control of Polarization and Intensity Profiles of Diffraction-Attenuation-Resistant Beams along the Propagation Direction

    Science.gov (United States)

    Corato-Zanarella, Mateus; Dorrah, Ahmed H.; Zamboni-Rached, Michel; Mojahedi, Mo

    2018-02-01

    We report on the theory and experimental generation of a class of diffraction-attenuation-resistant beams with state of polarization (SOP) and intensity that can be controlled on demand along the propagation direction. This control is achieved by a suitable superposition of Bessel beams, whose parameters are systematically chosen based on closed-form analytic expressions provided by the frozen waves method. Using an amplitude-only spatial light modulator, we experimentally demonstrate three scenarios. In the first, the SOP of a horizontally polarized beam evolves to radial polarization and is then changed to vertical polarization, with the beam intensity held constant. In the second, we simultaneously control the SOP and the longitudinal intensity profile, which is chosen such that the beam's central ring can be switched off over predefined space regions, thus generating multiple foci with different SOPs and at different intensity levels along the propagation. Finally, the ability to control the SOP while overcoming attenuation inside lossy fluids is shown experimentally. We envision our proposed method to be of great interest for many applications, such as optical tweezers, atom guiding, material processing, microscopy, and optical communications.

  10. Electron ionization and spin polarization control of Fe atom adsorbed graphene irradiated by a femtosecond laser

    International Nuclear Information System (INIS)

    Yu, Dong; Jiang, Lan; Wang, Feng; Li, Xin; Qu, Liangti; Lu, Yongfeng

    2015-01-01

    We investigate the structural properties and ionized spin electrons of an Fe–graphene system, in which the time-dependent density functional theory (TDDFT) within the generalized gradient approximation is used. The electron dynamics, including electron ionization and ionized electron spin polarization, is described for Fe atom adsorbed graphene under femtosecond laser irradiation. The theoretical results show that the electron ionization and ionized electron spin polarization are sensitive to the laser parameters, such as the incident angle and the peak intensity. The spin polarization presents the maximum value under certain laser parameters, which may be used as a source of spin-polarized electrons. - Highlights: • The structural properties of Fe–graphene system are investigated. • The electron dynamics of Fe–graphene system under laser irradiation are described. • The Fe–graphene system may be used as a source of spin-polarized electrons

  11. David Cronenberg y el cuerpo abierto

    Directory of Open Access Journals (Sweden)

    Johanna Rodríguez Ahumada

    2014-12-01

    Full Text Available En la sociedad actual, la relación entre el cuerpo y la tecnología ha planteado una de las fisuras más importantes en la concepción de la subjetividad. La enigmática y fascinante relación entre el humano y la máquina, explorada tanto por el cine como por otros (viejos y nuevos medios en el ámbito de la ciencia ficción, ha planteado la figura del cyborg u organismo cibernético como una criatura híbrida, ambigua, que rompe con la dicotomía naturaleza-artificialidad. ¿Cómo leer los nuevos productos culturales que surgen a raíz de la revolución tecnológica? El objeto de este estudio es Crash (David Cronenberg ,1995, que parte de una interpretación audiovisual de la novela de J.G. Ballard y aborda las fantasías de hibridación del yo con el otro, de lo orgánico con lo inorgánico; en últimas, de cuerpos en tránsito.

  12. Temperature sensitivity analysis of polarity controlled electrostatically doped tunnel field-effect transistor

    Science.gov (United States)

    Nigam, Kaushal; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

    2016-09-01

    The conventional tunnel field-effect transistors (TFETs) have shown potential to scale down in sub-22 nm regime due to its lower sub-threshold slope and robustness against short-channel effects (SCEs), however, sensitivity towards temperature variation is a major concern. Therefore, for the first time, we investigate temperature sensitivity analysis of a polarity controlled electrostatically doped tunnel field-effect transistor (ED-TFET). Different performance metrics and analog/RF figure-of-merits were considered and compared for both devices, and simulations were performed using Silvaco ATLAS device tool. We found that the variation in ON-state current in ED-TFET is almost temperature independent due to electrostatically doped mechanism, while, it increases in conventional TFET at higher temperature. Above room temperature, the variation in ION, IOFF, and SS sensitivity in ED-TFET are only 0.11%/K, 2.21%/K, and 0.63%/K, while, in conventional TFET the variations are 0.43%/K, 2.99%/K, and 0.71%/K, respectively. However, below room temperature, the variation in ED-TFET ION is 0.195%/K compared to 0.27%/K of conventional TFET. Moreover, it is analysed that the incomplete ionization effect in conventional TFET severely affects the drive current and the threshold voltage, while, ED-TFET remains unaffected. Hence, the proposed ED-TFET is less sensitive towards temperature variation and can be used for cryogenics as well as for high temperature applications.

  13. Corticosteroid solubility and lipid polarity control release from solid lipid nanoparticles.

    Science.gov (United States)

    Jensen, Louise B; Magnussson, Emily; Gunnarsson, Linda; Vermehren, Charlotte; Nielsen, Hanne M; Petersson, Karsten

    2010-05-05

    Solid lipid nanoparticles (SLN) show promise as a drug delivery system for skin administration. The solid state of the lipid particle enables efficient drug encapsulation and controlled drug release. The present study addresses the influence of lipid composition and drug substance lipid solubility on the in vitro release profile of corticosteroids from SLN for topical administration. Firstly, the effect of lipid composition on the lipid solubility and in vitro release of betamethasone-17-valerate (BMV) was determined by varying the lipid monoglyceride content and the chain length of the fatty acid moiety. Secondly, the effect of drug substance physicochemical properties was determined by studying five different corticosteroid derivatives with different lipophilicity. A high concentration of monoglyceride in SLN increased the amount of BMV released. The corticosteroid release rate depended on the drug substance lipophilicity and it was clear that the release profiles depended on drug partitioning to the aqueous phase as indicated by zero order kinetics. The results emphasize that the corticosteroid solubility in the lipid phase greatly influence drug distribution in the lipid particles and release properties. Thus knowledge of drug substance solubility and lipid polarity contributes to optimize SLN release properties. Copyright 2009 Elsevier B.V. All rights reserved.

  14. Into the development of a model to assess beam shaping and polarization control effects on laser cutting

    Science.gov (United States)

    Rodrigues, Gonçalo C.; Duflou, Joost R.

    2018-02-01

    This paper offers an in-depth look into beam shaping and polarization control as two of the most promising techniques for improving industrial laser cutting of metal sheets. An assessment model is developed for the study of such effects. It is built upon several modifications to models as available in literature in order to evaluate the potential of a wide range of considered concepts. This includes different kinds of beam shaping (achieved by extra-cavity optical elements or asymmetric diode staking) and polarization control techniques (linear, cross, radial, azimuthal). A fully mathematical description and solution procedure are provided. Three case studies for direct diode lasers follow, containing both experimental data and parametric studies. In the first case study, linear polarization is analyzed for any given angle between the cutting direction and the electrical field. In the second case several polarization strategies are compared for similar cut conditions, evaluating, for example, the minimum number of spatial divisions of a segmented polarized laser beam to achieve a target performance. A novel strategy, based on a 12-division linear-to-radial polarization converter with an axis misalignment and capable of improving cutting efficiency with more than 60%, is proposed. The last case study reveals different insights in beam shaping techniques, with an example of a beam shape optimization path for a 30% improvement in cutting efficiency. The proposed techniques are not limited to this type of laser source, neither is the model dedicated to these specific case studies. Limitations of the model and opportunities are further discussed.

  15. Development of a LabVIEW-based surface with innovative controls for the control system of the spin-polarized electron test source Photo-CATCH

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, Heidi Ayse; Enders, Joachim; Espig, Martin; Fritzsche, Yuliya; Wagner, Markus [TU Darmstadt, Institut fuer Kernphysik (Germany)

    2016-07-01

    Operations of the spin-polarized electron source of the S-DALINAC will be supported by a photo-cathode activation, test and cleaning system, Photo-CATCH. Besides cathode-performance studies, this teststand produces spin-polarized electron bunches from a GaAs photo-cathode that are then transported, manipulated, and characterized by devices in a low-energy beam line. To set and monitor the various components of the beamline, a control system was developed, based on the EPICS framework. As interfaces, LabVIEW was used in combination with a gamepad as a controlling device.

  16. Controlling the Eccentricity of Polar Lunar Orbits with Low-Thrust Propulsion

    Directory of Open Access Journals (Sweden)

    O. C. Winter

    2009-01-01

    Full Text Available It is well known that lunar satellites in polar orbits suffer a high increase on the eccentricity due to the gravitational perturbation of the Earth. That effect is a natural consequence of the Lidov-Kozai resonance. The final fate of such satellites is the collision with the Moon. Therefore, the control of the orbital eccentricity leads to the control of the satellite's lifetime. In the present work we study this problem and introduce an approach in order to keep the orbital eccentricity of the satellite at low values. The whole work was made considering two systems: the 3-body problem, Moon-Earth-satellite, and the 4-body problem, Moon-Earth-Sun-satellite. First, we simulated the systems considering a satellite with initial eccentricity equals to 0.0001 and a range of initial altitudes between 100 km and 5000 km. In such simulations we followed the evolution of the satellite's eccentricity. We also obtained an empirical expression for the length of time needed to occur the collision with the Moon as a function of the initial altitude. The results found for the 3-body model were not significantly different from those found for the 4-body model. Secondly, using low-thrust propulsion, we introduced a correction of the eccentricity every time it reached the value 0.05. These simulations were made considering a set of different thrust values, from 0.1 N up to 0.4 N which can be obtained by using Hall Plasma Thrusters. In each run we measured the length of time, needed to correct the eccentricity value (from e=0.04 to e=0.05. From these results we obtained empirical expressions of this time as a function of the initial altitude and as a function of the thrust value.

  17. Integrin-Mediated Interactions Control Macrophage Polarization in 3D Hydrogels

    NARCIS (Netherlands)

    Cha, Byung-Hyun; Ryon Shin, Su; Leijten, J.; Li, Yi-Chen; Singh, Sonali; Liu, Julie C.; Annabi, Nasim; Abdi, Reza; Dokmeci, Mehmet R.; Vrana, Nihal Engin; Ghaemmaghami, Amir M.; Khademhosseini, Ali

    2017-01-01

    Adverse immune reactions prevent clinical translation of numerous implantable devices and materials. Although inflammation is an essential part of tissue regeneration, chronic inflammation ultimately leads to implant failure. In particular, macrophage polarity steers the microenvironment toward

  18. Boundaries and interfaces in materials: The David A. Smith symposium

    International Nuclear Information System (INIS)

    Pond, R.C.; Clark, W.A.T.; King, A.H.; Williams, D.B.

    1998-01-01

    Just over a year ago David Smith died. Then the loss of a distinguished scientist and dedicated teacher was mourned. Now it is time to celebrate his accomplishments both as a scientist and teacher and this book serves as a reminder of his many contributions to the field of boundaries and interfaces. Researchers from ten countries contributed their work to the symposium, many of whom were former students of David from his years in Oxford. This emphasizes David's tremendous effect on the career of many established scientists through his role as both a teacher and an advisor. Separate abstracts were prepared for 38 papers in this book

  19. Dr. David Syz, State Secretary for Economic Affairs, Switzerland

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Dr. David Syz, State Secretary for Economic Affairs, Switzerland, toured the assembly hall of the ATLAS experiment on a recent visit to CERN.Photos 01, 02: Dr. Peter Jenni, spokesperson for the ATLAS experiment (second from left), explains to Dr. David Syz (fourth from left) and accompanying visitors the process of integration of a 26-metre-long coil of the barrel toroid magnet system into its coil casing.Photo 03: Dr. Peter Jenni (extreme right) with Dr. David Syz (front row, fourth from right) behind a stack of 26-metre-long 'racetrack' coils awaiting integration into their coil casings.

  20. Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

    DEFF Research Database (Denmark)

    Cortijo, Cedric; Gouzi, Mathieu; Tissir, Fadel

    2012-01-01

    Planar cell polarity (PCP) refers to the collective orientation of cells within the epithelial plane. We show that progenitor cells forming the ducts of the embryonic pancreas express PCP proteins and exhibit an active PCP pathway. Planar polarity proteins are acquired at embryonic day 11.5 synch...... that tridimensional organization and collective communication of cells are needed in the pancreatic epithelium in order to generate appropriate numbers of endocrine cells....

  1. Differential Polarization Nonlinear Optical Microscopy with Adaptive Optics Controlled Multiplexed Beams

    Directory of Open Access Journals (Sweden)

    Virginijus Barzda

    2013-09-01

    Full Text Available Differential polarization nonlinear optical microscopy has the potential to become an indispensable tool for structural investigations of ordered biological assemblies and microcrystalline aggregates. Their microscopic organization can be probed through fast and sensitive measurements of nonlinear optical signal anisotropy, which can be achieved with microscopic spatial resolution by using time-multiplexed pulsed laser beams with perpendicular polarization orientations and photon-counting detection electronics for signal demultiplexing. In addition, deformable membrane mirrors can be used to correct for optical aberrations in the microscope and simultaneously optimize beam overlap using a genetic algorithm. The beam overlap can be achieved with better accuracy than diffraction limited point-spread function, which allows to perform polarization-resolved measurements on the pixel-by-pixel basis. We describe a newly developed differential polarization microscope and present applications of the differential microscopy technique for structural studies of collagen and cellulose. Both, second harmonic generation, and fluorescence-detected nonlinear absorption anisotropy are used in these investigations. It is shown that the orientation and structural properties of the fibers in biological tissue can be deduced and that the orientation of fluorescent molecules (Congo Red, which label the fibers, can be determined. Differential polarization microscopy sidesteps common issues such as photobleaching and sample movement. Due to tens of megahertz alternating polarization of excitation pulses fast data acquisition can be conveniently applied to measure changes in the nonlinear signal anisotropy in dynamically changing in vivo structures.

  2. Differential polarization nonlinear optical microscopy with adaptive optics controlled multiplexed beams.

    Science.gov (United States)

    Samim, Masood; Sandkuijl, Daaf; Tretyakov, Ian; Cisek, Richard; Barzda, Virginijus

    2013-09-09

    Differential polarization nonlinear optical microscopy has the potential to become an indispensable tool for structural investigations of ordered biological assemblies and microcrystalline aggregates. Their microscopic organization can be probed through fast and sensitive measurements of nonlinear optical signal anisotropy, which can be achieved with microscopic spatial resolution by using time-multiplexed pulsed laser beams with perpendicular polarization orientations and photon-counting detection electronics for signal demultiplexing. In addition, deformable membrane mirrors can be used to correct for optical aberrations in the microscope and simultaneously optimize beam overlap using a genetic algorithm. The beam overlap can be achieved with better accuracy than diffraction limited point-spread function, which allows to perform polarization-resolved measurements on the pixel-by-pixel basis. We describe a newly developed differential polarization microscope and present applications of the differential microscopy technique for structural studies of collagen and cellulose. Both, second harmonic generation, and fluorescence-detected nonlinear absorption anisotropy are used in these investigations. It is shown that the orientation and structural properties of the fibers in biological tissue can be deduced and that the orientation of fluorescent molecules (Congo Red), which label the fibers, can be determined. Differential polarization microscopy sidesteps common issues such as photobleaching and sample movement. Due to tens of megahertz alternating polarization of excitation pulses fast data acquisition can be conveniently applied to measure changes in the nonlinear signal anisotropy in dynamically changing in vivo structures.

  3. Differential Polarization Nonlinear Optical Microscopy with Adaptive Optics Controlled Multiplexed Beams

    Science.gov (United States)

    Samim, Masood; Sandkuijl, Daaf; Tretyakov, Ian; Cisek, Richard; Barzda, Virginijus

    2013-01-01

    Differential polarization nonlinear optical microscopy has the potential to become an indispensable tool for structural investigations of ordered biological assemblies and microcrystalline aggregates. Their microscopic organization can be probed through fast and sensitive measurements of nonlinear optical signal anisotropy, which can be achieved with microscopic spatial resolution by using time-multiplexed pulsed laser beams with perpendicular polarization orientations and photon-counting detection electronics for signal demultiplexing. In addition, deformable membrane mirrors can be used to correct for optical aberrations in the microscope and simultaneously optimize beam overlap using a genetic algorithm. The beam overlap can be achieved with better accuracy than diffraction limited point-spread function, which allows to perform polarization-resolved measurements on the pixel-by-pixel basis. We describe a newly developed differential polarization microscope and present applications of the differential microscopy technique for structural studies of collagen and cellulose. Both, second harmonic generation, and fluorescence-detected nonlinear absorption anisotropy are used in these investigations. It is shown that the orientation and structural properties of the fibers in biological tissue can be deduced and that the orientation of fluorescent molecules (Congo Red), which label the fibers, can be determined. Differential polarization microscopy sidesteps common issues such as photobleaching and sample movement. Due to tens of megahertz alternating polarization of excitation pulses fast data acquisition can be conveniently applied to measure changes in the nonlinear signal anisotropy in dynamically changing in vivo structures. PMID:24022688

  4. Eesti keel barbarite suus / David J. Peterson ; intervjueerinud Peeter Helme

    Index Scriptorium Estoniae

    Peterson, David J.

    2011-01-01

    USA telekanali HBO telesarjas "Troonide mäng" (mis on George R. R. Martini "Jää ja tule laulu" sarja esimese raamatu "Troonide mäng" teleekraniseering) tegeles dothraki keele loomisega keeleteadlane David J. Peterson

  5. Kommunist mittekommunisti ei usalda / David Satter ; interv. Viktor Niitsoo

    Index Scriptorium Estoniae

    Satter, David

    2005-01-01

    Tallinnas esitles oma raamatut "Meeletuste ajastu. Nõukogude Liidu allakäik ja langus" Finacial Times'i endine Moskva korrespondent David Satter, tegemist on NL-i viimase viieteistkümne aasta koondkroonikaga. Intervjuus meenutab David Satter oma tööaastaid Moskvas 1976-1982. a., kus ta keskendus põhiliselt ühiskondlik-poliitilistele teemadele, kaasa arvatud dissidentlik liikumine. Suhted võimudega, KGB provokatsioonid

  6. Optical packet networks - conclusions from the IST DAVID project

    DEFF Research Database (Denmark)

    Dittmann, Lars

    2004-01-01

    This work outlines the result from the European research project DAVID working with optical packet switch solutions for both WAN and MAN. The project started July 2000 and has been completed successfully by the end of 2003.......This work outlines the result from the European research project DAVID working with optical packet switch solutions for both WAN and MAN. The project started July 2000 and has been completed successfully by the end of 2003....

  7. Polarization-Controlled Broad Color Palette Based on an Ultrathin One-Dimensional Resonant Grating Structure

    Science.gov (United States)

    Koirala, Ishwor; Shrestha, Vivek Raj; Park, Chul-Soon; Lee, Sang-Shin; Choi, Duk-Yong

    2017-01-01

    Highly efficient polarization-tuned structural color filters, which are based on a one- dimensional resonant aluminum grating that is integrated with a silicon nitride waveguide, are proposed and demonstrated to feature a broad color palette. For such a metallic grating structure, transmissive color filtering is only feasible for the incident transverse-magnetic (TM) polarization due to its high reflection regarding the transverse-electric (TE) case; however, polarization-tuned customized colors can be efficiently achieved by optimizing the structural parameters like the duty ratio of the metallic grating. For the fabricated color filters, the transmission peaks, which are imputed to the resonance between the incident light and the guided modes that are supported by the dielectric waveguide, provided efficiencies as high as 90% and 70% for the TM and TE polarizations, respectively, as intended. Through the tailoring of the polarization, a group of filters with different grating periods were successfully exploited to produce a broad color palette spanning the entire visible band. Lastly, a nanoscale alphabetic pattern featuring a flexible combination of colorations was practically constructed via an arrangement of horizontal and vertical gratings.

  8. Flexible Holographic Fabrication of 3D Photonic Crystal Templates with Polarization Control through a 3D Printed Reflective Optical Element

    Directory of Open Access Journals (Sweden)

    David Lowell

    2016-07-01

    Full Text Available In this paper, we have systematically studied the holographic fabrication of three-dimensional (3D structures using a single 3D printed reflective optical element (ROE, taking advantage of the ease of design and 3D printing of the ROE. The reflective surface was setup at non-Brewster angles to reflect both s- and p-polarized beams for the interference. The wide selection of reflective surface materials and interference angles allow control of the ratio of s- and p-polarizations, and intensity ratio of side-beam to central beam for interference lithography. Photonic bandgap simulations have also indicated that both s and p-polarized waves are sometimes needed in the reflected side beams for maximum photonic bandgap size and certain filling fractions of dielectric inside the photonic crystals. The flexibility of single ROE and single exposure based holographic fabrication of 3D structures was demonstrated with reflective surfaces of ROEs at non-Brewster angles, highlighting the capability of the ROE technique of producing umbrella configurations of side beams with arbitrary angles and polarizations and paving the way for the rapid throughput of various photonic crystal templates.

  9. Polarization Optics

    OpenAIRE

    Fressengeas, Nicolas

    2010-01-01

    The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.

  10. How many molecular layers of polar solvent molecules control chemistry? The concept of compensating dipoles.

    Science.gov (United States)

    Langhals, Heinz; Braun, Patricia; Dietl, Christian; Mayer, Peter

    2013-09-27

    The extension of the solvent influence of the shell into the volume of a polar medium was examined by means of anti-collinear dipoles on the basis of the E(T)(30) solvent polarity scale (i.e., the molar energy of excitation of a pyridinium-N-phenolatebetaine dye; generally: E(T) =28,591 nm kcal mol(-1)/λmax) where no compensation effects were found. As a consequence, solvent polarity effects are concentrated to a very thin layer of a few thousand picometres around the solute where extensions into the bulk solvent become unimportant. A parallelism to the thin surface layer of water to the gas phase is discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Arbitrary control of the polarization and intensity profiles of diffraction-attenuation-resistant beams along their propagation direction

    OpenAIRE

    Corato-Zanarella, Mateus; Dorrah, Ahmed H.; Zamboni-Rached, Michel; Mojahedi, Mo

    2017-01-01

    We report on the theory and experimental generation of a class of diffraction-attenuation-resistant beams with state of polarization (SoP) and intensity that can be controlled on demand along the propagation direction. This is achieved by a suitable superposition of Bessel beams, whose parameters are systematically chosen based on closed-form analytic expressions provided by the Frozen Waves (FWs) method. Using an amplitude-only spatial light modulator, we experimentally demonstrate three sce...

  12. Polarization Controlled Ohmic to Schottky Transition at a Metal/Doped Ferroelectric Interface

    OpenAIRE

    Liu, Xiaohui; Wang, Yong; Burton, J. D.; Tsymbal, Evgeny Y.

    2013-01-01

    Ferroelectric polar displacements have recently been observed in conducting electron-doped BaTiO3. The co-existence of a ferroelectric phase and conductivity opens the door to new functionalities which may provide a unique route for novel device applications. Using first-principles methods and electrostatic modeling we explore the effect that the switchable polarization of electron-doped BaTiO3 (n-BaTiO3) has on the electronic properties of the SrRuO3/n-BaTiO3 (001) interface. Ferroelectric p...

  13. c21orf59/kurly Controls Both Cilia Motility and Polarization

    Directory of Open Access Journals (Sweden)

    Kimberly M. Jaffe

    2016-03-01

    Full Text Available Cilia are microtubule-based projections that function in the movement of extracellular fluid. This requires cilia to be: (1 motile and driven by dynein complexes and (2 correctly polarized on the surface of cells, which requires planar cell polarity (PCP. Few factors that regulate both processes have been discovered. We reveal that C21orf59/Kurly (Kur, a cytoplasmic protein with some enrichment at the base of cilia, is needed for motility; zebrafish mutants exhibit characteristic developmental abnormalities and dynein arm defects. kur was also required for proper cilia polarization in the zebrafish kidney and the larval skin of Xenopus laevis. CRISPR/Cas9 coupled with homologous recombination to disrupt the endogenous kur locus in Xenopus resulted in the asymmetric localization of the PCP protein Prickle2 being lost in mutant multiciliated cells. Kur also makes interactions with other PCP components, including Disheveled. This supports a model wherein Kur plays a dual role in cilia motility and polarization.

  14. Optical reconfiguration and polarization control in semi-continuous gold films close to the percolation threshold

    DEFF Research Database (Denmark)

    Frydendahl, Christian; Repän, Taavi; Geisler, Mathias

    2017-01-01

    permanent morphological changes with a femtosecond (fs)-pulsed laser above a critical power. Optical transmission spectroscopy measurements show a correlation between the spectra of the morphologically modified films and the wavelength, polarization, and the intensity of the laser used for alteration...

  15. Obituary: David Fulmer Bender, 1913-2004

    Science.gov (United States)

    Miller, Sylvia L.

    2004-12-01

    David Fulmer Bender died in San Diego, California, on 13 September 2004, at the age of 91. His heart stopped suddenly while he was dancing. His pioneering work in establishing comprehensive, computer-accessible ephemerides of asteroids and comets found many applications, including the first-ever visit to an asteroid, Gaspra, by an interplanetary spacecraft. Dave was born in Reno, Nevada, on 10 February 1913, to Homer Charles Bender and Susan Bowers Bender. The family moved to Spokane, Washington, while Dave was very young. His father was a civil engineer and a graduate of MIT, who helped design bridges and dams throughout the Northwest, including the Grand Coolie Dam. Dave had a brother, Phillip (now deceased), who was one year younger. Advancing rapidly in the Spokane school system, Dave finished high school when he was 15 years old. At 16 he moved to Pasadena, California, and began his studies at the California Institute of Technology (Caltech). In addition to pursuing his course work, he was active in track and football, a tendency toward physical exercise that stayed with him for the rest of his life. It was probably during these years that Dave heard a lecture by Albert Einstein, as mentioned to colleagues many years later. Dave received a BS degree in physics in 1933, an MS in 1934, and a PhD in 1937, all from Caltech. His dissertation was entitled, "The Index of Refraction of Air in the Photographic Infrared." During his sophomore year he found his way to Pomona College in Claremont, California, where he met his future wife, Elizabeth Boyden at a social gathering. They were married in 1935. Dave's academic career spanned the years from 1937 to 1970, initially at Louisiana State University, Vanderbilt University, and then Fisk. As a life-long pacifist and conscientious objector, Dave served alternate duty during World War II. In 1946 he joined the faculty of the physics department at Whittier College in California, where he became the department chair and

  16. Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field.

    Science.gov (United States)

    Ghali, Mohsen; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo

    2012-02-07

    Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton-exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72 ± 0.05.

  17. Polarization controlled deep sub-wavelength periodic features written by femtosecond laser on nanodiamond thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Kuntumalla, Mohan; Srikanth, Vadali V. S. S., E-mail: vvsssse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Rajamudili, Kuladeep; Rao Desai, Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-04-21

    Deep sub-wavelength (Λ/λ = ∼0.22) periodic features are induced uniformly on a nanodiamond (ND) thin film surface using femtosecond (fs) laser irradiation (pulse duration = ∼110 fs and central wavelength of ∼800 nm). The topography of the surface features is controlled by the laser polarization. Orientation of features is perpendicular to laser polarization. Periodicity (spatial periodicity of < λ/4) of the surface features is less than the laser wavelength. This work gives an experimental proof of polarization controlled surface plasmon-fs laser coupling mechanism prompting the interaction between fs laser and solid matter (here ND thin film) which in turn is resulting in the periodic surface features. Scanning electron microscopy in conjunction with micro Raman scattering, X-ray diffraction, and atomic force microscopy are carried out to extract surface morphology and phase information of the laser irradiated regions. This work demonstrates an easy and efficient surface fabrication technique.

  18. Phase- and Polarization-Controlled Two-Photon Rabi Oscillation of the Biexciton State in a Semiconductor Quantum Dot

    Directory of Open Access Journals (Sweden)

    Erlin Sun

    2014-01-01

    Full Text Available Under a degenerate two-photon resonant excitation, the Rabi oscillation of the four-level biexciton system in a semiconductor quantum dot is theoretically investigated. The influence of the laser phases on the state manipulation is modeled and numerically calculated. Due to the interference between different excitation paths, the laser phase plays an important role and can be utilized as an alternate control knob to coherently manipulate the biexciton state. The phase control can be facilely implemented by changing the light polarization via a quarter-wave plate.

  19. Issues of choice and control in the behaviour of a pair of captive polar bears (Ursus maritimus).

    Science.gov (United States)

    Ross, Stephen R

    2006-07-01

    Stereotyped behaviour occurs in a wide variety of captive animals including ursids. The provision of animal control over aspects of their environment by providing choices is a critical element for improving welfare. The behaviour of two sibling polar bears at a metropolitan zoo was examined to investigate the effect of providing access to their indoor, off-exhibit holding space. Both bears demonstrated behavioural changes when given the choice to access their indoor dens including decreased stereotyped behaviours and increased social play. These results, although based on just two bears, provide additional support for the assertion that choice and control are closely tied to issues of well-being for captive animals.

  20. Controlling electron-electron correlation in frustrated double ionization of triatomic molecules with orthogonally polarized two-color laser fields

    Science.gov (United States)

    Chen, A.; Kling, M. F.; Emmanouilidou, A.

    2017-09-01

    We demonstrate the control of electron-electron correlation in frustrated double ionization (FDI) of the two-electron triatomic molecule D3 + when driven by two orthogonally polarized two-color laser fields. We employ a three-dimensional semiclassical model that fully accounts for the electron and nuclear motion in strong fields. We analyze the FDI probability and the distribution of the momentum of the escaping electron along the polarization direction of the longer wavelength and more intense laser field. These observables, when considered in conjunction, bear clear signatures of the prevalence or absence of electron-electron correlation in FDI, depending on the time delay between the two laser pulses. We find that D3 + is a better candidate than H2 for demonstrating also experimentally that electron-electron correlation indeed underlies FDI.

  1. Control of Electronic Conduction at an Oxide Heterointerface using Surface Polar Adsorbates

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Christopher

    2011-08-19

    We study the effect of the surface adsorption of a variety of common laboratory solvents on the conductivity at the interface between LaAlO{sub 3} and SrTiO{sub 3}. This interface possesses a range of intriguing physics, notably a proposed connection between the surface state of the LaAlO{sub 3} and the conductivity buried in the SrTiO{sub 3}. We show that the application of chemicals such as acetone, ethanol, and water can induce a large change (factor of three) in the conductivity. This phenomenon is observed only for polar solvents. These data provide experimental evidence for a general polarization-facilitated electronic transfer mechanism.

  2. INTRODUCTION: David Sherrington as a mentor of young scientists

    Science.gov (United States)

    Goldbart, Paul M.

    2008-08-01

    How deeply honoured I am to have the opportunity to express my thoughts at this delightful celebration of David's achievements, so far, in his remarkable career. I have been asked to center my remarks on David's contributions to the mentoring and professional development of scientists early in their careers. This is a topic that I am more than happy to reflect on, because it gives me the opportunity to recall the exciting period I spent as one of David's postgraduate students at Imperial College in the early 1980s. It also gives me the chance to publicly express my gratitude to David for the opportunities he created for me at that time, as well as for the interest and care he has shown in my career and well-being ever since, as we have met up and exchanged news and ideas around the world: in New Mexico and Colorado, in Cancun, Paris and Trieste, at numerous March Meetings of the American Physical Society and, of course in London, Oxford, and my home town, Champaign-Urbana, location of the University of Illinois. I have been a member of David's circle for 25 years now, and I would like to tell you a little about how this came to be. Not because of what this says about me, but, rather, because of what it tells you about David and the rich generosity of his spirit and effort when it comes to supporting the underdog. I was indeed one such underdog—and that's putting it charitably—when I first met David in September of 1982, not long before the academic year was to begin. I had heard about the exciting circle of physical and mathematical ideas swirling around the spin glass question during the previous year, which I had spent at the University of California's Los Angeles campus, through an opportunity kindly arranged, as it happens, by Sam Edwards. But I was eager to return to the UK for postgraduate studies and to work on spin glasses, so I simply showed up at David's Imperial College office, unannounced (if I remember correctly). And with his characteristic

  3. Solvent polarity controls the helical conformation of short peptides rich in Calpha-tetrasubstituted amino acids.

    Science.gov (United States)

    Bellanda, Massimo; Mammi, Stefano; Geremia, Silvano; Demitri, Nicola; Randaccio, Lucio; Broxterman, Quirinus B; Kaptein, Bernard; Pengo, Paolo; Pasquato, Lucia; Scrimin, Paolo

    2007-01-01

    The two peptides, rich in C(alpha)-tetrasubstituted amino acids, Ac-[Aib-L-(alphaMe)Val-Aib](2)-L-His-NH(2) (1) and Ac-[Aib-L-(alphaMe)Val-Aib](2)-O-tBu (2 a) are prevalently helical. They present the unique property of changing their conformation from the alpha- to the 3(10)-helix as a function of the polarity of the solvent: alpha in more polar solvents, 3(10) in less polar ones. Conclusive evidence of this reversible change of conformation is reported on the basis of the circular dichroism (CD) spectra and a detailed two-dimensional NMR analysis in two solvents (trifluoroethanol and methanol) refined with molecular dynamics calculations. The X-ray diffractometric analysis of the crystals of both peptides reveals that they assume a prevalent 3(10)-helix conformation in the solid state. This conformation is practically superimposable on that obtained from the NMR analysis of 1 in methanol. The NMR results further validate the reported CD signature of the 3(10)-helix and the use of the CD technique for its assessment.

  4. Waging war against pancreatic cancer: an interview with David Tuveson

    Directory of Open Access Journals (Sweden)

    David Tuveson

    2017-04-01

    Full Text Available David Tuveson, Director of the Cancer Center at Cold Spring Harbor Laboratory, is a clinician-scientist with a longstanding interest in understanding and treating pancreatic cancer. Since developing the first mouse model of pancreatic cancer in 2002, the Tuveson lab has made a series of discoveries that shed light on the molecular drivers of this disease and provide promising therapeutic avenues for a malignancy that is notoriously challenging to treat. In collaboration with Hans Clevers, David developed the first pancreatic cancer organoids, which revolutionized the field by providing a powerful model system for basic discoveries and advancement of personalized medicine. Here, David talks to Ross Cagan about his path from chemistry student to world-renowned oncologist, highlighting how his colleagues, mentors and patient interactions shaped his research interests and unique approach to scientific discovery. As well as discussing the story behind some of his breakthroughs, he provides tips on running a lab and succeeding in or outside academia.

  5. “From the Mind of David Simon”

    DEFF Research Database (Denmark)

    Jensen, Mikkel Bo Brendstrup

    2017-01-01

    of the issues with reading several television series together. The article further argues that television scholar Erlend Lavik’s term “focused overarching authorship” supports the validity in trying to tease out a collected vision in Simon’s television serials. For while David Simon is a sine qua non......This article makes a case for the academic soundness of reading together several television shows by the same showrunner. Zeroing in on the case of David Simon, the essay traces the difficulties that one faces if one aims to view together The Corner, The Wire, Generation Kill, Treme, Show Me a Hero...

  6. Optical reconfiguration and polarization control in semicontinuous gold films close to the percolation threshold

    DEFF Research Database (Denmark)

    Frydendahl, Christian; Repän, Taavi; Geisler, Mathias

    In this work we have studied the intrinsic and reconfigured optical properties of semi-continuous gold films, fabricated via a simple metal evaporation technique. We have prepared three films of nominal thicknesses 5, 6, and 7nm. After fabrication the films are illuminated in areas by scanning a fs......-pulsed laser over the films (Fig. 1). This results in permament morphological changes in the films observed in a scanning transmission electron microscope (STEM), see Fig. 2. The laser writing also introduces a polarized feature in the transmission spectra of the films. We have performed electron energy...

  7. Control of coercive field in lithium niobate crystals with repeated polarization reversal

    International Nuclear Information System (INIS)

    Ro, Jung Hoon; Jeong, Doun; Park, Taeyong; Kim, Chulhan; Kwon, Soon-Bok; Cha, Myoungsik; Choi, Byeong Cheol; Yu, Nanei; Kurimura, Sunao; Jeon, Gyerok

    2005-01-01

    In this study, the amount of decrease in coercive field of congruent lithium niobate during repeated poling and back-poling was measured. The polarization is reversed in 300 ms and then back-poled during the rest period. The coercive field can be decreased around 1 kV/mm with a repeated poling interval of 5 s. As the interval prolonged, the poling field decrease became smaller, and a stretched exponential function is suggested for the experimental fitting resulting in a set of meaningful parameters. These values are essential for the design of high quality domain engineering

  8. Controllably releasing long-lived quantum memory for photonic polarization qubit into multiple spatially-separate photonic channels.

    Science.gov (United States)

    Chen, Lirong; Xu, Zhongxiao; Zeng, Weiqing; Wen, Yafei; Li, Shujing; Wang, Hai

    2016-09-26

    We report an experiment in which long-lived quantum memories for photonic polarization qubits (PPQs) are controllably released into any one of multiple spatially-separate channels. The PPQs are implemented with an arbitrarily-polarized coherent signal light pulses at the single-photon level and are stored in cold atoms by means of electromagnetic-induced-transparency scheme. Reading laser pulses propagating along the direction at a small angle relative to quantum axis are applied to release the stored PPQs into an output channel. By changing the propagating directions of the read laser beam, we controllably release the retrieved PPQs into 7 different photonic output channels, respectively. At a storage time of δt = 5 μs, the least quantum-process fidelity in 7 different output channels is ~89%. At one of the output channels, the measured maximum quantum-process fidelity for the PPQs is 94.2% at storage time of δt = 0.85 ms. At storage time of 6 ms, the quantum-process fidelity is still beyond the bound of 78% to violate the Bell's inequality. The demonstrated controllable release of the stored PPQs may extend the capabilities of the quantum information storage technique.

  9. Dr. David Sawyer, Mickey Mouse and Dr. David Brown attend a ceremony at Ronald McNair Middle School

    Science.gov (United States)

    1999-01-01

    Dr. David Sawyer (left), Superintendent of the Brevard County School District, Mickey Mouse, and Dr. David Brown, a NASA astronaut, attend a tribute to NASA astronaut Ronald McNair held in the gymnasium of Ronald McNair Magnet School in Cocoa, Fla. During the tribute, Walt Disney World presented a portrait of McNair to the school, which had previously been renamed for the fallen astronaut. McNair was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  10. The New American University. Twelfth David Dodds Henry Lecture.

    Science.gov (United States)

    Rhodes, Frank H. T.

    This publication presents the text of a speech by the president of Cornell University on the future of American universities. The speech is preceded by a brief preface describing the origin and history of the David Dodds Henry lecture series, and by the original introduction to the speaker delivered by president Stanley O. Ikenberry of the…

  11. Voorzitter van de Joodse Raad. De herinneringen van David Cohen

    NARCIS (Netherlands)

    Somers, E.L.M.

    2010-01-01

    Geen instantie heeft na de oorlog zo onder vuur gelegen vanwege haar functioneren tijdens de Duitse bezetting als de Joodsche Raad. Hoofdrolspeler in deze bewogen jaren was prof. David Cohen, samen met Abraham Asscher voorzitter van de Joodse Raad. Op verzoek van prof. Jacques Presser en dr. Loe de

  12. "David Byrne really does love PowerPoint"

    DEFF Research Database (Denmark)

    van Leeuwen, Theo; Djonov, Emilia

    2014-01-01

    This article presents a reading if David Byrne's Envisioning Emotional Epistemological Information, an art work created with Microsoft's presentation software PowerPoint, as an instance of creative research on semiotics and semiotic technology. It reveals commonalities and differences between Byr...

  13. 2012-2013 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-2013 Expense report for David Malone. Download PDF of Expense Report 2012-2013 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  14. 2010-2011 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-2011 Expense report for David Malone. Download PDF of Expense Report 2010-2011 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  15. 2011-2012 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-2012 Expense report for David Malone. Download PDF of Expense Report 2011-2012 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  16. Fatboy Slim ja David Byrne teevad Imelda Marcosest muusikali

    Index Scriptorium Estoniae

    2005-01-01

    Inglise DJ Fatboy Slim'i ja USA art-rockmuusiku David Byrne'i diskokeskne muusikal "Here Love Lives" kajastab Filipiinide diktaatori Ferdinand Macrose abikaasa elu. Muusikal esietendub tuleva aasta märtsis Austraalias Adelaide'i kultuurifestivalil, Euroopa esietendus toimub seejärel Liverpoolis

  17. David M. Malone - President Travel Expenses 2009-10

    International Development Research Centre (IDRC) Digital Library (Canada)

    test

    David M. Malone - President. Travel Expenses 2009-10. Other. Travel. Other. Meals &. Expenses. Total. Amount. Net Expenses. Organization. Dates. Destination(s). Purpose. Airfare. Transportation. Hotels. Incidentals. (note 1). Expenses. Recovered. Paid by IDRC. Recovered from. Feb-10. Waterloo, ON. Prior Period ...

  18. Battling Creaticide: An Interview with David C. Berliner

    Science.gov (United States)

    Ambrose, Don

    2012-01-01

    This article presents an interview with David C. Berliner, a Regents' Professor in the College of Education at Arizona State University. His books include "Educational Psychology," "The Manufactured Crisis," and "The Handbook of Educational Psychology." He has served as president of the American Educational Research Association and of the…

  19. In Memoriam: David Judson Sencer, A Public Health Giant

    Centers for Disease Control (CDC) Podcasts

    2011-12-15

    Dr. Jeffery Koplan, Director of the Emory Global Health Institute at Emory University, reflects on the career of Dr. David Sencer.  Created: 12/15/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/19/2011.

  20. Fighting for the Past: Lessons from the David Irving Trial

    Science.gov (United States)

    Henderson, A. Scott

    2008-01-01

    This article offers lessons from the David Irving trial. These lessons about Holocaust denial allow educators to identify how deniers violate certain scholarly tenets. This also serves as a safeguard against legitimizing deniers' efforts, while also reinforcing important principles of historical inquiry. (Contains 11 notes.)

  1. Drawing borders of mental disorders : An interview with David Kupfer

    NARCIS (Netherlands)

    Verhoeff, Berend

    2010-01-01

    The new Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is on its way and will most likely be published in 2013. The chair of the task force of this significant project, Dr David Kupfer, was in the Netherlands at a national psychiatry conference to give an update on its progress.

  2. Comments on forty chairs in four feet by David Rowland

    DEFF Research Database (Denmark)

    I forbindelse med 40-års jubilæet for David Rowlands stol ”40/4” har 22 internationale designere skabt deres egne fortolkninger af stolen Danske designere på udstillingen: Finn Sködt, Louise Campbell, Nanna Ditzel, Erik Simonsen, Boris Berlin & Poul Christiansen, Hans Sandgren Jakobsen Redaktøren...

  3. Child Welfare Research and Training: A Response to David Stoesz

    Science.gov (United States)

    Smith, Brenda D.; Vandiver, Vikki L.

    2016-01-01

    In this response to David Stoesz' critique, "The Child Welfare Cartel," the authors agree that child welfare research and training must be improved. The authors disagree, however, with Stoesz' critique of social work education, his assessment of the most-needed forms of child welfare research, and his depiction of the goals and…

  4. 2009-2010 Expense report for David Malone | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2009-2010 Expense report for David Malone. Download PDF of Expense Report 2009-2010 · What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open ...

  5. "The Word I Would Use Is 'Aesthetic'": Reading David Hawkins.

    Science.gov (United States)

    Featherstone, Helen; Featherstone, Joseph

    2002-01-01

    Discusses the life of David Hawkins, one of the most influential educators involved in school reform in the 1960s. Focuses on the aesthetic as the center of Hawkins' vision of schooling. Compares Hawkins' perspective to Dewey's in terms of the aesthetic. (KHR)

  6. Some transculturalist aspects in David Maillu's Broken Drum

    African Journals Online (AJOL)

    epistolary works, theatre plays, and didactic and historical non-fiction. David. Gian Maillu, was born in 1939 among the Akamba people of Eastern Kenya. ... Part of Maillu's success is due to his marketing strategies through his own pub- lishing house, Comb Books, established in the early 1970s. Maillu's "frankness" led to a ...

  7. The Dutch and Portuguese-Jewish Background of David Ricardo

    NARCIS (Netherlands)

    Heertje, A.

    2004-01-01

    This article deals with the Dutch and Portuguese-Jewish background of David Ricardo. The important pieces of information, found in the Amsterdam municipal archives, on the one hand correct, and on the other complement, the data presented by P. Sraffa. Recently, new evidence has been found on

  8. Nähtamatu revolutsioon / David R. Smith ; interv. Philip Ball

    Index Scriptorium Estoniae

    Smith, David R.

    2007-01-01

    Tehisstruktuuriga metamaterjalid võivad põhjapanevalt muuta telekommunikatsiooni, andmekandjaid ja isegi päikeseenergeetikat, kinnitab Dukeѫi ülikooli töörühma juht David R. Smith. Artikkel üldpealkirja all: 10 tulevikutehnoloogiat 2007

  9. David M. Malone - President Hospitality Expenses 2008-09

    International Development Research Centre (IDRC) Digital Library (Canada)

    test

    David M. Malone - President. Travel Expenses 2008-09. Other. Travel. Other. Meals &. Expenses. Total. Amount. Net Expenses. Organization. Dates. Destination(s). Purpose. Airfare. Transportation. Hotels. Incidentals. (note 1). Expenses. Recovered. Paid by IDRC. Recovered from. August 21 - 22. Kingston, ON. Discussions ...

  10. Empowering Adolescent Readers: Intertextuality in Three Novels by David Almond

    Science.gov (United States)

    Latham, Don

    2008-01-01

    In "Skellig," "Kit's Wilderness," and "Clay", David Almond employs various types of intertextuality to enrich his narratives. Through the use of allusion, adaptation, collage, and mise-en-abyme, he encourages his adolescent readers to seek out precursor texts and to consider the interrelationships between these texts and his own. By so doing, he…

  11. Highlight: Dr David Butler-Jones on fighting pandemics | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    15 avr. 2016 ... Dr David Butler-Jones, professor in the Faculty of Medicine at the University of Manitoba and former Chief Medical Health Officer of Canada, delivered a lecture on lessons learned from the 2009 flu pandemic in Canada. He also commented on India's draft National Health Policy 2015 at the India ...

  12. Making Sense of Seeing: Autism and David Marr.

    Science.gov (United States)

    Kellman, Julia

    1996-01-01

    Reviews the work of neurobiologist, David Marr, concerning artistic ability and autism. Summarizes Marr's theory of perceptual vision illuminating the relationships among object, observer, perceptual process, and image. Briefly reviews the cases of four autistic people with extraordinary drawing skills. (MJP)

  13. Compensation of negative sequence stator flux of doubly-fed induction generator using polar voltage control-based direct torque control under unbalanced grid voltage condition

    Directory of Open Access Journals (Sweden)

    Badrinarayan Bansilal Pimple

    2015-02-01

    Full Text Available This study proposes a polar voltage control-based direct torque control method to reduce the effects of unbalanced grid voltage on doubly-fed induction generator (DFIG-based wind turbine system. Under unbalanced grid voltage, the stator flux has a negative sequence component which leads to second harmonic pulsation in torque, stator active power, stator reactive power, stator current and rotor current. In the control scheme, the negative sequence rotor voltage vector is controlled to compensate the negative sequence stator flux by negative sequence rotor flux. Simulation study is carried out on a 2 MW DFIG system using MATLAB/SIMULINK. Feasibility of the proposed control strategy is experimentally verified on a 1.5 kW DFIG system.

  14. David Bruce Payton : väikeriigid mõistavad üksteist / David Bruce Payton ; interv. Marianne Mikko

    Index Scriptorium Estoniae

    Payton, David Bruce

    2003-01-01

    Uus-Meremaa suursaadik Eestis David Bruce Payton talupidaja toetamise loobumisest Uus-Meremaal, Uus-Meremaa põllumajandussektorist, veinidest, ekspordist, Eesti saamisest EL-i ja NATO liikmeks, Uus-Meremaa rahvastikust, elatustasemest, Iraagi võimalikust ründamisest, Põhja-Koreast

  15. Analysis and Control of Buck-Boost Converter with the Same Input Polarity Based on Novel Energy Factor Evaluation

    Directory of Open Access Journals (Sweden)

    Mahmoud Shaker Nasr

    2017-03-01

    Full Text Available This paper presents firstly a buck-boost circuit with the advantage that its output voltage polarity is the same as the input polarity. The circuit operation is presented and analyzed in different modes of operation. The well known parameters used in evaluation of DC/DC converters like Total Harmonic Distortion THD, Power Factor PF, and Ripple Factor RF have no meaning in DC/DC converters, so it is to introduce efficient concepts to permit a fair evaluation of the converter. This paper present other parameters that can be used to study the characteristics of the converter and gives a real and logic means of its operation. These main parameters are: pumping energy PE, storage energy SE, energy factor EF, and energy losses EL. In addition, the converter efficiency is not considered as 100 % as taken in most analyzing studies. The positive DC/DC buck-boost converter is evaluated according to the new concepts and the system model is deduced for different cases of operation taking into account the resistance of the circuit inductor. The circuit is implemented practically and the presented obtained results show the correct operation under different modes of operation. In addition the control design of the converter is built such that a PI controller with windup is considered. In order to test the effectiveness of the designed control algorithm, the system were exposed to different voltage reference values and the obtained results demonstrate that the system responses for all cases are very acceptable according to the criteria of the control system theory.

  16. Polarization feedback laser stabilization

    Science.gov (United States)

    Esherick, P.; Owyoung, A.

    1987-09-28

    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

  17. A novel adaptive controller for two-degree of freedom polar robot with unknown perturbations

    Science.gov (United States)

    Faieghi, Mohammad Reza; Delavari, Hadi; Baleanu, Dumitru

    2012-02-01

    In industrial applications, the performance of robot manipulators is always affected due to the presence of uncertainties and disturbances. This paper proposes a novel adaptive control scheme for robust control of robotic manipulators perturbed by unknown uncertainties and disturbances. First, an active sliding mode controller is designed and a sufficient condition is obtained guarantying reachability of the states to hit the sliding surface in finite time. Then, based on a Lyapunov function candidate an adaptive switching gain is derived which make the controller capable to bring the tracking error to zero without any disturbance exerted upon the stability. By virtue of this controller it can be shown that the controller can track the desired trajectories even in the presence of unknown perturbations. For the problem of determining the control parameters Particle Swarm Optimization (PSO) algorithm has been employed. Our theoretic achievements are verified by numerical simulations.

  18. Bichromatic coherent random lasing from dye-doped polymer stabilized blue phase liquid crystals controlled by pump light polarization

    Science.gov (United States)

    Wang, Lei; Wang, Meng; Yang, Mingchao; Shi, Li-Jie; Deng, Luogen; Yang, Huai

    2016-09-01

    In this paper, we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals. Two groups of lasing peaks, of which the full widith at half maximum is about 0.3 nm, are clearly observed. The shorter- and longer-wavelength modes are associated with the excitation of the single laser dye (DCM) monomers and dimers respectively. The experimental results show that the competition between the two groups of the lasing peaks can be controlled by varying the polarization of the pump light. When the polarization of the pump light is rotated from 0° to 90°, the intensity of the shorter-wavelength lasing peak group reduces while the intensity of the longer-wavelength lasing peak group increases. In addition, a red shift of the longer-wavelength modes is also observed and the physical mechanisms behind the red-shift phenomenon are discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474021 and 51333001), the Key Program for International S&T Cooperation Projects of China (Grant No. 2013DFB50340), the Issues of Priority Development Areas of the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120001130005), and the Key (Key Grant) Project of Chinese Ministry of Education (Grant No. 313002).

  19. Engineering and control of cold molecules. Making manipulating and exploiting ultra-cold polar molecules

    International Nuclear Information System (INIS)

    Bigelow, N.P.; Haimberger, C.; Kleinert, J.; Tscherneck, M.; Holmes, M.E.

    2005-01-01

    In the last 12 months several groups have demonstrated the use of photo association to create cold heteronuclear (polar) molecules. We report on the formation of translationally cold NaCs molecules starting from a laser-cooled atomic vapor of Na and Cs atoms. Colliding atoms are transferred into bound molecular states in a two-step photoactivated process. We find a translational temperature of T ≅ 260 mK. To increase the density and number of trapped atoms, dark-spot techniques are used on the MOT and a Zeeman slowed sodium beam is used to load the sodium atoms into the trap. Spectroscopy of these molecules is underway using time-of-flight ion detection and trap-loss. Initial REMPI measurements indicate that both singlet and triplet states are being populated by the spontaneous-decay driven process. We measure a rate constant for molecule formation of K NaCs = 7.43 · 10 15 cm 3 s -1 . (author)

  20. Nonsequential double ionization channels control of Ar with few-cycle elliptically polarized laser pulse by carrier-envelope-phase.

    Science.gov (United States)

    Ben, Shuai; Wang, Tian; Xu, Tongtong; Guo, Jing; Liu, Xueshen

    2016-04-04

    The carrier-envelop-phase (CEP) dependence of nonsequential double ionization (NSDI) of atomic Ar with few-cycle elliptically polarized laser pulse is investigated using 2D classical ensemble method. We distinguish two particular recollision channels in NSDI, which are recollision-impact ionization (RII) and recollision-induced excitation with subsequent ionization (RESI). We separate the RII and RESI channels according to the delay time between recollision and final double ionization. By tracing the history of the trajectories, we find the electron correlation spectra as well as the competition between the two channels are sensitively dependent on the laser field CEP. Finally, control can be achieved between the two channels by varying the CEP.

  1. David Bohm la physique de l'infini

    CERN Document Server

    Teodorani, Massimo

    2014-01-01

    Les idées de David Bohm, indépendamment du scepticisme de ses collègues les plus traditionalistes, ont profondément influencé la physique du siècle dernier et ouvert une porte à la physique du nouveau millénaire. Grâce aussi aux contacts qu'il sut nouer avec des chercheurs d'autres branches du savoir, ses idées ont été accueillies avec beaucoup d'enthousiasme par les neuroscientifiques, les philosophes, les théologiens, les psychologues, les sociologues, les poètes, les artistes et les éducateurs. David Bohm avait peut-être pressenti qu'il existe une "physique de l'âme" et avec elle il voulait tracer un nouveau chemin pour une humanité à la dérive.

  2. Pupazzi di neve. David Lynch fotografo e l’"Unheimliche"

    Directory of Open Access Journals (Sweden)

    Paolo Sebastiano Lanzi

    2013-02-01

    Full Text Available L’opera di David Lynch non si limita al cinema, come ha dimostrato l’esposizione del 2007 alla Fondation Cartier di Parigi, The Air is on Fire. Tuttavia gli studi teorici hanno trascurato ciò che gallerie e musei hanno evidenziato da tempo: il Lynch pittore, fotografo, musicista, artista poliedrico. L’articolo si focalizza su una serie fotografica, Snowmen, ed è tratto da una ricerca di Paolo Sebastiano Lanzi sulla figura di David Lynch fotografo. Alla luce del saggio di Freud sul Perturbante (Das Unheimliche, 1919 si interpretano gli Snowmen come immagini di morte. Si chiariscono alcuni aspetti della poetica dell’artista-regista, come l’inquietudine dell’Inland Empire o di certe idee care al Surrealismo. Lo studio della produzione fotografica di Lynch riempie un vuoto nell’analisi critica sul suo lavoro, che va necessariamente riconsiderato in una prospettiva più ampia.

  3. 2690-IJBCS-Article-N'goran David Vincent K

    African Journals Online (AJOL)

    hp

    durant le cycle de reproduction. N'Goran David Vincent KOUAKOU* et Yao ..... basée notamment sur la non rétention sélective des fluides et des particules du .... (1) Taux de fécondité : nombre de petits nés/Nombre de femelles mises en reproduction ; (2) P.m.m.b. : poids moyen des reproductrices à la mise bas ; (3) P.m.n. ...

  4. Princípiosnorteadores da filosofia moral de David Hume

    Directory of Open Access Journals (Sweden)

    André Luiz Holanda de Oliveira

    2017-02-01

    Full Text Available O presente artigo objetiva apresentar os princípios norteadores da filosofia moral de David Hume. Para tanto se buscará demonstrar que a razão é escrava das paixões, que os juízos morais não são demonstráveis, nem refletem a realidade objetiva, para por fim, demonstrar a importância da utilidade.

  5. David Cronenberg, author of naked lunch: Intersemiotic translation as transcreation

    Directory of Open Access Journals (Sweden)

    Rosângela Fachel de Medeiros

    2016-08-01

    Full Text Available This paper presents and analyzes the intersemiotic translation process performed by filmmaker David Cronenberg of William Burroughs' novel Naked Lunch, and the intertextual bifurcations involved in this process. Investigating the similarities and differences between the creative worlds of both artists and how they reframe each other. For this, are used as the theoretical the idea of transcreation proposed by Haroldo de Campos, and the notion of the translator as a reader proposed by Jorge Luis Borges.

  6. Dr. David Syz, State Secretary for Economic Affairs, Switzerland

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Dr. David Syz, State Secretary for Economic Affairs, Switzerland is seen here (seventh from right) visiting the assembly hall for the ATLAS experiment during his recent visit to CERN. To his right is Dr. Peter Jenni (blue shirt), spokesperson for the ATLAS Collaboration. The horizontal metal cylinder behind the group is one of the eight vacuum vessels for the superconducting coils of the ATLAS barrel toroid magnet system.

  7. David Cronenberg, author of naked lunch: Intersemiotic translation as transcreation

    Directory of Open Access Journals (Sweden)

    Rosângela Fachel de Medeiros

    2016-05-01

    Full Text Available This paper presents and analyzes the intersemiotic translation process performed by filmmaker David Cronenberg of William Burroughs' novel Naked Lunch, and the intertextual bifurcations involved in this process. Investigating the similarities and differences between the creative worlds of both artists and how they reframe each other. For this, are used as the theoretical the idea of transcreation proposed by Haroldo de Campos, and the notion of the translator as a reader proposed by Jorge Luis Borges.

  8. Tunable and rotatable polarization controller using photonic crystal fiber filled with liquid crystal

    DEFF Research Database (Denmark)

    Wei, Lei; Alkeskjold, Thomas Tanggaard; Bjarklev, Anders Overgaard

    2010-01-01

    is managed by connecting four electrodes in different electrode configurations, and the thermal tunability is controlled by on-chip heaters. According to the results, a quarter-wave plate and a half-wave plate working in the wavelength range of 1520–1600 nm are experimentally demonstrated....

  9. Frizzled3 controls axonal polarity and intermediate target entry during striatal pathway development

    NARCIS (Netherlands)

    Morello, Francesca; Prasad, Asheeta A.; Rehberg, Kati; Baptista Vieira de Sá, Renata; Antón-Bolaños, Noelia; Leyva-Diaz, Eduardo; Adolfs, Youri; Tissir, Fadel; López-Bendito, Guillermina; Pasterkamp, R. Jeroen

    2015-01-01

    The striatum is a large brain nucleus with an important role in the control of movement and emotions.Mediumspiny neurons (MSNs) are striatal output neurons forming prominent descending axon tracts that target different brain nuclei. However, how MSN axon tracts in the forebrain develop remains

  10. Repeating ice-earthquakes beneath David Glacier from the 2012-2015 TAMNNET array

    Science.gov (United States)

    Walter, J. I.; Peng, Z.; Hansen, S. E.

    2017-12-01

    The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. In recent years, improvements in seismic instrumentation, battery technology, and field deployment practices have allowed for continuous broadband stations throughout the dark Antarctic winter. We utilize broadband seismic data from a recent experiment (TAMNNET), which was originally proposed as a structural seismology experiment, for seismic event detection. Our target is to address fundamental questions about regional-scale crustal and environmental seismicity in the study region that comprises the Transantarctic Mountain area of Victoria and Oates Land. We identify most seismicity emanating from David Glacier, upstream of the Drygalski Ice Tongue, which has been documented by several other studies. In order to improve the catalog completeness for the David Glacier area, we utilize a matched-filter technique to identify potential missing earthquakes that may not have been originally detected. This technique utilizes existing cataloged waveforms as templates to scan through continuous data and to identify repeating or nearby earthquakes. With a more robust catalog, we evaluate relative changes in icequake positions, recurrence intervals, and other first-order information. In addition, we attempt to further refine locations of other regional seismicity using a variety of methods including body and surface wave polarization, beamforming, surface wave dispersion, and other seismological methods. This project highlights the usefulness of archiving raw datasets (i.e., passive seismic continuous data), so that researchers may apply new algorithms or techniques to test hypotheses not originally or specifically targeted by the original experimental design.

  11. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  12. Delivery strategies to control inflammatory response: Modulating M1-M2 polarization in tissue engineering applications

    OpenAIRE

    Alvarez, Mario Moisés; Liu, Julie C.; Santiago, Grissel Trujillo-de; Cha, Byung-Hyun; Vishwakarma, Ajaykumar; Ghaemmaghami, Amir; Khademhosseini, Ali

    2016-01-01

    Macrophages are key players in many physiological scenarios including tissue homeostasis. In response to injury, typically the balance between macrophage sub-populations shifts from an M1 phenotype (pro-inflammatory) to an M2 phenotype (anti-inflammatory). In tissue engineering scenarios, after implantation of any device, it is desirable to exercise control on this M1-M2 progression and to ensure a timely and smooth transition from the inflammatory to the healing stage. In this review, we bri...

  13. Controlling electron quantum paths for generation of circularly polarized high-order harmonics by H2+ subject to tailored (ω , 2 ω ) counter-rotating laser fields

    Science.gov (United States)

    Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.

    2018-04-01

    Recently, studies of high-order harmonics (HHG) from atoms driven by bichromatic counter-rotating circularly polarized laser fields as a source of coherent circularly polarized extreme ultraviolet (XUV) and soft-x-ray beams in a tabletop-scale setup have received considerable attention. Here, we demonstrate the ability to control the electron recollisions giving three returns per one cycle of the fundamental frequency ω by using tailored bichromatic (ω , 2 ω ) counter-rotating circularly polarized laser fields with a molecular target. The full control of the electronic pathway is first analyzed by a classical trajectory analysis and then extended to a detailed quantum study of H2+ molecules in bichromatic (ω , 2 ω ) counter-rotating circularly polarized laser fields. The radiation spectrum contains doublets of left- and right-circularly polarized harmonics in the XUV ranges. We study in detail the below-, near-, and above-threshold harmonic regions and describe how excited-state resonances alter the ellipticity and phase of the generated harmonic peaks.

  14. Control of triplet state generation in heavy atom-free BODIPY-anthracene dyads by media polarity and structural factors.

    Science.gov (United States)

    Filatov, Mikhail A; Karuthedath, Safakath; Polestshuk, Pavel M; Callaghan, Susan; Flanagan, Keith J; Telitchko, Maxime; Wiesner, Thomas; Laquai, Frédéric; Senge, Mathias O

    2018-03-28

    A family of heavy atom-free BODIPY-anthracene dyads (BADs) exhibiting triplet excited state formation from charge-transfer states is reported. Four types of BODIPY scaffolds, different in the alkyl substitution pattern, and four anthracene derivatives have been used to access BADs. Fluorescence and intersystem crossing (ISC) in these dyads depend on donor-acceptor couplings and can be accurately controlled by substitution or media polarity. Under conditions that do not allow charge transfer (CT), the dyads exhibit fluorescence with high quantum yields. Formation of charge-transfer states triggers ISC and the formation of long-lived triplet excited states in the dyads. The excited state properties were studied by steady-state techniques and ultrafast pump-probe spectroscopy to determine the parameters of the observed processes. Structural information for various BADs was derived from single crystal X-ray structure determinations alongside DFT molecular geometry optimization, revealing the effects of mutual orientation of subunits on the photophysical properties. The calculations showed that alkyl substituents on the BODIPY destabilize CT states in the dyads, thus controlling the charge transfer between the subunits. The effect of the dyad structure on the ISC efficiency was considered at the M06-2X level of theory, and a correlation between mutual orientation of the subunits and the energy gap between singlet and triplet CT states was studied using a multireference CASSCF method.

  15. Controlled and Efficient Polymerization of Conjugated Polar Alkenes by Lewis Pairs Based on Sterically Hindered Aryloxide-Substituted Alkylaluminum

    Directory of Open Access Journals (Sweden)

    Xiaojun Wang

    2018-02-01

    Full Text Available Reported herein is the development of an effective strategy for controlled and efficient Lewis pair polymerization of conjugated polar alkenes, including methyl methacrylate (MMA, n-butyl methacrylate (nBuMA, and γ-methyl-α-methylene-γ-butyrolactone (γMMBL, by the utilization of sterically encumbered Al(BHT2Me (BHT: 2,6-di-tert-butyl-4-methylphenol as a Lewis acid that shuts down intramolecular backbiting termination. In combination with a selected N-heterocyclic carbene (NHC as a Lewis base, the polymerization of MMA exhibited activity up to 3000 h−1 TOF and an acceptable initiation efficiency of 60.6%, producing polymers with high molecular weight (Mn up to 130 kg/mol and extremely narrow dispersity (Đ = 1.06~1.13. This controlled polymerization with a living characteristic has been evidenced by chain-extension experiments and chain-end analysis, and enabled the synthesis of well-defined diblock copolymers.

  16. Biophysical Attributes of CpG Presentation Control TLR9 Signaling to Differentially Polarize Systemic Immune Responses

    Directory of Open Access Journals (Sweden)

    Jardin A. Leleux

    2017-01-01

    Full Text Available It is currently unknown whether and how mammalian pathogen recognition receptors (PRRs respond to biophysical patterns of pathogen-associated molecular danger signals. Using synthetic pathogen-like particles (PLPs that mimic physical properties of bacteria or large viruses, we have discovered that the quality and quantity of Toll-like receptor 9 (TLR9 signaling by CpG in mouse dendritic cells (mDCs are uniquely dependent on biophysical attributes; specifically, the surface density of CpG and size of the presenting PLP. These physical patterns control DC programming by regulating the kinetics and magnitude of MyD88-IRAK4 signaling, NF-κB-driven responses, and STAT3 phosphorylation, which, in turn, controls differential T cell responses and in vivo immune polarization, especially T helper 1 (Th1 versus T helper 2 (Th2 antibody responses. Our findings suggest that innate immune cells can sense and respond not only to molecular but also pathogen-associated physical patterns (PAPPs, broadening the tools for modulating immunity and helping to better understand innate response mechanisms to pathogens and develop improved vaccines.

  17. Control of triplet state generation in heavy atom-free BODIPY-anthracene dyads by media polarity and structural factors

    KAUST Repository

    Filatov, Mikhail A.

    2018-02-12

    A family of heavy atom-free BODIPY-anthracene dyads (BADs) exhibiting triplet excited state formation from charge-transfer states is reported. Four types of BODIPY scaffolds, different in the alkyl substitution pattern, and four anthracene derivatives have been used to access BADs. The fluorescence and intersystem crossing (ISC) in these dyads depend on donor-acceptor couplings and can be accurately controlled by the substitution or media polarity. Under conditions that do not allow charge transfer (CT), the dyads exhibit fluorescence with high quantum yields. Formation of charge-transfer states triggers ISC and the formation of long-lived triplet excited states in the dyads. The excited state properties were studied by steady-state techniques and ultrafast pump-probe spectroscopy to determine the parameters of the observed processes. Structural information for various BADs was derived from single crystal X-ray structure determinations alongside DFT molecular geometry optimization, revealing the effects of mutual orientation of subunits on the photophysical properties. The calculations showed that alkyl substituents on the BODIPY destabilize CT states in the dyads, thus controlling the charge transfer between the subunits. The effect of the dyad structure on the ISC efficiency was considered at M06-2X level of theory and a correlation between mutual orientation of the subunits and the energy gap between singlet and triplet CT states was studied using multireference CASSCF method.

  18. Rac1 controls epithelial tube length through the apical secretion and polarity pathways

    Directory of Open Access Journals (Sweden)

    Kévin Sollier

    2016-01-01

    Full Text Available The morphometric parameters of epithelial tubes are critical to the physiology and homeostasis of most organs. In addition, many human diseases are associated with tube-size defects. Here, we show that Rac1 limits epithelial tube elongation in the developing fly trachea by promoting Rab5-dependent endocytosis of the apical determinant Crumbs. Rac1 is also involved in a positive feedback loop with the septate junction protein Coracle. Thereby, Rac1 precludes paracellular diffusion and contributes to the septate junction-dependent secretion of the chitin-modifying enzymes Vermiform and Serpentine, which restrict epithelial tube length independently of Crumbs. Thus, Rac1 is a critical component of two important pathways controlling epithelial tube morphogenesis.

  19. On the use of polarization modulation in combined interferometry and polarimetry. Corrigendum. 1998 Plasma Phys. Control. Fusion, v. 40 p. 153-161

    International Nuclear Information System (INIS)

    Segre, S.E.

    1998-01-01

    Errors in the main text, the appendix and two curves are corrected in this corrigendum to the paper entitled ''On the use of polarization modulation in combined interferometry and polarimetry'', written by S.E. Segre and published in 1998 Plasma Phys. Control. Fusion, v. 40 p. 153-161

  20. Quality Control and Calibration of the Dual-Polarization Radar at Kwajalein, RMI

    Science.gov (United States)

    Marks, David A.; Wolff, David B.; Carey, Lawrence D.; Tokay, Ali

    2010-01-01

    Weather radars, recording information about precipitation around the globe, will soon be significantly upgraded. Most of today s weather radars transmit and receive microwave energy with horizontal orientation only, but upgraded systems have the capability to send and receive both horizontally and vertically oriented waves. These enhanced "dual-polarimetric" (DP) radars peer into precipitation and provide information on the size, shape, phase (liquid / frozen), and concentration of the falling particles (termed hydrometeors). This information is valuable for improved rain rate estimates, and for providing data on the release and absorption of heat in the atmosphere from condensation and evaporation (phase changes). The heating profiles in the atmosphere influence global circulation, and are a vital component in studies of Earth s changing climate. However, to provide the most accurate interpretation of radar data, the radar must be properly calibrated and data must be quality controlled (cleaned) to remove non-precipitation artifacts; both of which are challenging tasks for today s weather radar. The DP capability maximizes performance of these procedures using properties of the observed precipitation. In a notable paper published in 2005, scientists from the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) at the University of Oklahoma developed a method to calibrate radars using statistically averaged DP measurements within light rain. An additional publication by one of the same scientists at the National Severe Storms Laboratory (NSSL) in Norman, Oklahoma introduced several techniques to perform quality control of radar data using DP measurements. Following their lead, the Topical Rainfall Measuring Mission (TRMM) Satellite Validation Office at NASA s Goddard Space Flight Center has fine-tuned these methods for specific application to the weather radar at Kwajalein Island in the Republic of the Marshall Islands, approximately 2100 miles

  1. RHIC Polarized proton operation

    International Nuclear Information System (INIS)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-01-01

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP 4 . A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  2. RHIC Polarized proton operation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D' Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  3. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  4. David Bohm : causality and chance, letters to three women

    CERN Document Server

    2017-01-01

    The letters transcribed in this book were written by physicist David Bohm to three close female acquaintances in the period 1950 to 1956. They provide a background to his causal interpretation of quantum mechanics and the Marxist philosophy that inspired his scientific work in quantum theory, probability and statistical mechanics. In his letters, Bohm reveals the ideas that led to his ground breaking book Causality and Chance in Modern Physics. The political arguments as well as the acute personal problems contained in these letters help to give a rounded, human picture of this leading scientist and twentieth century thinker.

  5. An Interview with David Dabydeen on Literature and Politics

    OpenAIRE

    Ruzbeh Babaee

    2016-01-01

    Professor David Dabydeen is a Guyanese-born writer, critic and academic at the Centre of Caribbean Studies at the University of Warwick. In 1993 he became Guyana's ambassador at UNESCO and is still a member of their Executive Board. He has been Guyana's ambassador to China since 2010. Professor Dabydeen has also won several international and national prizes such as the Commonwealth Poetry Prize, the Quiller-Couch Prize, and the Hind Rattan (Jewel of India). Among his works are Slave Song (198...

  6. David Kasner, MD, and the Road to Pars Plana Vitrectomy

    Directory of Open Access Journals (Sweden)

    Christopher F. Blodi

    2016-01-01

    Full Text Available David Kasner, MD (1927–2001, used his extensive dissections of eye bank eyes and experiences in teaching cataract surgery to resident physicians to realize that excision of vitreous when present in the anterior chamber of eyes undergoing cataract surgery was preferable to prior intraoperative procedures. Noting that eyes tolerated his maneuvers, he then performed planned subtotal open-sky vitrectomies; first on a traumatized eye in 1961, then on two eyes of patients with amyloidosis (1966–1967. The success of these operations was noted by others, most particularly Robert Machemer, MD. Kasner's work directly led to further surgical developments, including closed pars plana vitrectomy.

  7. De hombres y monstruos: El hombre elefante, David Lynch, 1980

    OpenAIRE

    Ferrer, Anacleto

    2012-01-01

    Nacido en Leicester en 1862, Joseph Carey Merrick tuvo un desarrollo normal durante la primera parte de su infancia, hasta los 5 años, cuando aparecieron las primeras manifestaciones de su extraña enfermedad:El síndrome de Proteus. Esta emotiva película sobre su caso fue estrenada en 1980 por el cineasta británico David Lynch, un prolífico creador que viene cultivando con éxito distintas formas de expresión artística que alterna con sus rodajes. De este modo ha conseguido transmitir un u...

  8. Optical and microwave control of resonance fluorescence and squeezing spectra in a polar molecule

    Science.gov (United States)

    Antón, M. A.; Maede-Razavi, S.; Carreño, F.; Thanopulos, I.; Paspalakis, E.

    2017-12-01

    A two-level quantum emitter with broken inversion symmetry simultaneously driven by an optical field and a microwave field that couples to the permanent dipole's moment is presented. We focus to a situation where the angular frequency of the microwave field is chosen such that it closely matches the Rabi frequency of the optical field, the so-called Rabi resonance condition. Using a series of unitary transformations we obtain an effective Hamiltonian in the double-dressed basis which results in easily solvable Bloch equations which allow us to derive analytical expressions for the spectrum of the scattered photons. We analyze the steady-state population inversion of the system which shows a distinctive behavior at the Rabi resonance with regard to an ordinary two-level nonpolar system. We show that saturation can be produced even in the case that the optical field is far detuned from the transition frequency, and we demonstrate that this behavior can be controlled through the intensity and the angular frequency of the microwave field. The spectral properties of the scattered photons are analyzed and manifest the emergence of a series of Mollow-like triplets which may be spectrally broadened or narrowed for proper values of the amplitude and/or frequency of the low-frequency field. We also analyze the phase-dependent spectrum which reveals that a significant enhancement or suppression of the squeezing at certain sidebands can be produced. These quantum phenomena are illustrated in a recently synthesized molecular complex with high nonlinear optical response although they can also occur in other quantum systems with broken inversion symmetry.

  9. The Ecological Controls on the Prevalence of Candidate Division TM7 in Polar Regions

    Directory of Open Access Journals (Sweden)

    Tristrom eWinsley

    2014-07-01

    Full Text Available The candidate division TM7 is ubiquitous and yet uncultured phylum of the Bacteria that encompasses a commonly environmental associated clade, TM7-1, and a ‘host-associated’ clade, TM7-3. However, as members of the TM7 phylum have not been cultured, little is known about what differs between these two clades. We hypothesized that these clades would have different environmental niches. To test this, we used a large-scale global soil dataset, encompassing 223 soil samples, their environmental parameters and associated bacterial 16S rRNA gene sequence data. We correlated chemical, physical and biological parameters of each soil with the relative abundance of the two major classes of the phylum to deduce factors that influence the groups’ seemingly ubiquitous nature. The two classes of the phylum (TM7-1 and TM7-3 were indeed distinct from each other in their habitat requirements. A key determinant of each class’ prevalence appears to be the pH of the soil. The class TM7-1 displays a facultative anaerobic nature with correlations to more acidic soils with total iron, silicon, titanium and copper indicating a potential for siderophore production. However, the TM7-3 class shows a more classical oligotrophic, heterotroph nature with a preference for more alkaline soils, and a probable pathogenic role with correlations to extractable iron, sodium and phosphate. In addition, the TM7-3 was abundant in diesel contaminated soils highlighting a resilient nature along with a possible carbon source. In addition to this both classes had unique co-occurrence relationships with other bacterial phyla. In particular, both groups had opposing correlations to the Gemmatimonadetes phylum, with the TM7-3 class seemingly being outcompeted by this phylum to result in a negative correlation. These ecological controls allow the characteristics of a TM7 phylum preferred niche to be defined and give insight into possible avenues for cultivation of this previously

  10. d-PET-controlled “off-on” Polarity-sensitive Probes for Reporting Local Hydrophilicity within Lysosomes

    Science.gov (United States)

    Zhu, Hao; Fan, Jiangli; Mu, Huiying; Zhu, Tao; Zhang, Zhen; Du, Jianjun; Peng, Xiaojun

    2016-10-01

    Polarity-sensitive fluorescent probes are powerful chemical tools for studying biomolecular structures and activities both in vitro and in vivo. However, the lack of “off-on” polarity-sensing probes has limited the accurate monitoring of biological processes that involve an increase in local hydrophilicity. Here, we design and synthesize a series of “off-on” polarity-sensitive fluorescent probes BP series consisting of the difluoroboron dippyomethene (BODIPY) fluorophore connected to a quaternary ammonium moiety via different carbon linkers. All these probes showed low fluorescence quantum yields in nonpolar solution but became highly fluorescent in polar media. BP-2, which contains a two-carbon linker and a trimethyl quaternary ammonium, displayed a fluorescence intensity and quantum yield that were both linearly correlated with solvent polarity. In addition, BP-2 exhibited high sensitivity and selectivity for polarity over other environmental factors and a variety of biologically relevant species. BP-2 can be synthesized readily via an unusual Mannich reaction followed by methylation. Using electrochemistry combined with theoretical calculations, we demonstrated that the “off-on” sensing behavior of BP-2 is primarily due to the polarity-dependent donor-excited photoinduced electron transfer (d-PET) effect. Live-cell imaging established that BP-2 enables the detection of local hydrophilicity within lysosomes under conditions of lysosomal dysfunction.

  11. Inhibitors of Apoptosis Protein Antagonists (Smac Mimetic Compounds Control Polarization of Macrophages during Microbial Challenge and Sterile Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Vinod Nadella

    2018-01-01

    Full Text Available Apoptosis is a physiological cell death process essential for development, tissue homeostasis, and for immune defense of multicellular animals. Inhibitors of apoptosis proteins (IAPs regulate apoptosis in response to various cellular assaults. Using both genetic and pharmacological approaches we demonstrate here that the IAPs not only support opportunistic survival of intracellular human pathogens like Chlamydia pneumoniae but also control plasticity of iNOS+ M1 macrophage during the course of infection and render them refractory for immune stimulation. Treatment of Th1 primed macrophages with birinapant (IAP-specific antagonist inhibited NO generation and relevant proteins involved in innate immune signaling. Accordingly, birinapant promoted hypoxia, angiogenesis, and tumor-induced M2 polarization of iNOS+ M1 macrophages. Interestingly, birinapant-driven changes in immune signaling were accompanied with changes in the expression of various proteins involved in the metabolism, and thus revealing the new role of IAPs in immune metabolic reprogramming in committed macrophages. Taken together, our study reveals the significance of IAP targeting approaches (Smac mimetic compounds for the management of infectious and inflammatory diseases relying on macrophage plasticity.

  12. Attitudes of Mississippi college students toward David Duke before and after seeing the film Who is David Duke?

    Science.gov (United States)

    Eisenman, R; Girdner, E J; Burroughs, R G; Routman, M

    1993-01-01

    The attitudes of 211 students at a university in Mississippi were investigated both before and after seeing the Public Broadcasting Film Who Is David Duke? The film provided evidence of Duke's current racism, anti-Semitism, and pro-Nazi leanings. In a previous study with university students in Louisiana, the majority did not change their attitudes after watching the film (Eisenman, 1993). However, in the present study, students' attitudes showed change in an anti-Duke direction. The findings are discussed and reasons given for the differences between the two samples, and for the popularity of Duke, a former leader of the Ku Klux Klan.

  13. The Will to Touch: David Copperfield’s Hand

    Directory of Open Access Journals (Sweden)

    Pamela K. Gilbert

    2014-10-01

    Full Text Available In the nineteenth century, touch was considered to be a more privileged sense than has been generally noted, and the hand was pre-eminently the site of active touching. The hand comes newly to rival the face in descriptive significance in mid-nineteenth-century fiction, and reflects contemporary notions of the role of touch in the exercise of the will and the development of the sensorium. This article explores medical and philosophical understandings of embodied touch within the period, and examines why the hand emerged as a focal point for scientific, poetic, and popular discussion. Such scientists as Charles Bell, Herbert Spencer, and Alexander Bain tend to work within two paradigms: the hand as a site of sensory input that forms a conduit between inner and outer worlds, and the hand as an instrument of the will. The article explores Dickens's use of these ideas about touch and development in his 1850 'Bildungsroman', 'David Copperfield'. David struggles to establish his proper status as a middle-class male, in part by learning to use his hands to impose his own will and to resist the dominance of inappropriate others through touch.

  14. David Kelley et la politique de la complicité

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Esquenazi

    2011-04-01

    Full Text Available La télévision est liée à sa diffusion familiale, comme le prouve l’histoire américaine de la télévision. Les séries télévisées sont elles-mêmes attachées à ce contexte. Elles multiplient les marques rituelles de reconnaissance. David Kelley, auteur de Ally Mc Beal ou de Boston Legal, aime jouer avec cette nécessité. Il crée une relation de complicité entre ses personnages et le téléspectateur. Le texte en étudie les principales figures.Television is linked to its family broadcasting; American history reminds us of it. And television series are tied to this context. They multiply signs of recognition. David Kelley, Ally Mc Beal or Boston Legal's producer, likes to play with this necessity. He creates a relation of complicity between his figures and the viewer. This text studies his main methods.

  15. Polarization, political

    NARCIS (Netherlands)

    Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2015-01-01

    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass

  16. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  17. Commentary on "Asynchronous Preparation of Tonally Fused Intervals in Polyphonic Music" by David Huron

    Directory of Open Access Journals (Sweden)

    James Wright

    2008-05-01

    Full Text Available In his most recent contribution to an important and well-framed series of papers on auditory grouping and the perception of polyphonic music, David Huron seeks further evidence for his working hypothesis that J.S. Bach controls the employment of perfect consonances by desynchronizing their onsets, thereby inhibiting the perceptual fusion of polyphonic voices. However the more novel contribution of the present study would seem to be its demonstration that Bach also regulates the employment of dissonant tones by consistently desynchronizing their onsets. This finding provides the first concrete evidence for Wright and Bregman’s otherwise untested hypothesis that the control and salience of dissonance in polyphonic music are closely related to principles of auditory stream segregation (Wright, 1986; Wright & Bregman, 1987.

  18. Polar Bears

    Science.gov (United States)

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  19. Primary productivity as a control over soil microbial diversity along environmental gradients in a polar desert ecosystem

    Directory of Open Access Journals (Sweden)

    Kevin M. Geyer

    2017-07-01

    Full Text Available Primary production is the fundamental source of energy to foodwebs and ecosystems, and is thus an important constraint on soil communities. This coupling is particularly evident in polar terrestrial ecosystems where biological diversity and activity is tightly constrained by edaphic gradients of productivity (e.g., soil moisture, organic carbon availability and geochemical severity (e.g., pH, electrical conductivity. In the McMurdo Dry Valleys of Antarctica, environmental gradients determine numerous properties of soil communities and yet relatively few estimates of gross or net primary productivity (GPP, NPP exist for this region. Here we describe a survey utilizing pulse amplitude modulation (PAM fluorometry to estimate rates of GPP across a broad environmental gradient along with belowground microbial diversity and decomposition. PAM estimates of GPP ranged from an average of 0.27 μmol O2/m2/s in the most arid soils to an average of 6.97 μmol O2/m2/s in the most productive soils, the latter equivalent to 217 g C/m2/y in annual NPP assuming a 60 day growing season. A diversity index of four carbon-acquiring enzyme activities also increased with soil productivity, suggesting that the diversity of organic substrates in mesic environments may be an additional driver of microbial diversity. Overall, soil productivity was a stronger predictor of microbial diversity and enzymatic activity than any estimate of geochemical severity. These results highlight the fundamental role of environmental gradients to control community diversity and the dynamics of ecosystem-scale carbon pools in arid systems.

  20. David Hume filósofo e historiador

    Directory of Open Access Journals (Sweden)

    Sara Albieri

    2004-12-01

    Full Text Available Among all the great philosophers, David Hume has the rare merit of joining to a properly philosophical work an equally important output as historian. According to him, the interpretation of history by means of the general principles of political theory must not be guided by ethical or normative considerations, as when judging historic events according to what things ought to be, for instance, in view of the best government, but it should be restricted to explain the exercise of power in the different times, just as it can be established by the testimony of the sources. Only this methodological attitude allows us to avoid the partisan interpretations that try to justify the present by the past, instead of investigating it to corroborate the most appropriate explanation.

  1. Quantenmechanik im Kalten Krieg David Bohm und Richard Feynman

    CERN Document Server

    Forstner, Christian

    2007-01-01

    Mitte des 20. Jahrhunderts entwickelten David Bohm und Richard Feynman zwei grundlegend verschiedene Ansätze der moderne Quantenmechanik: Bohm eine realistische Deutung mit Hilfe verborgener Parameter und Feynman den Pfadintegralformalismus. Dies ist umso bemerkenswerter, weil beide Physiker von ähnlichen Voraussetzungen ausgingen und aus ähnlichen Zusammenhängen stammten. Durch ihren vergleichenden Ansatz bietet diese Studie mehr als einen Beitrag zur Geschichte der Quantentheorie. Mit der Frage nach den sozialen und kulturellen Bedingungen der Theoriebildung ist sie darüberhinaus von wissenschaftssoziologischem und wissenschaftstheoretischem Interesse. Die anfangs ähnliche und später unterschiedliche Einbindung der beiden Wissenschaftler in die Scientific Community erlaubt es überdies zu untersuchen, welchen Anpassungsdruck die jeweilige Gruppe auf den individuellen Wissenschaftler und die Kernbestandteile seiner Forschungen ausübt und welche neuen Freiheitsgrade für die Theoriebildung entstehen, ...

  2. Infinite potential the life and times of David Bohm

    CERN Document Server

    Peat, David

    1997-01-01

    Throughout his life, David Bohm felt himself to be different, and this was reflected in his lifestyle and in his physics. His life was one of unfulfilled searching. If one compares mainstream physics to the church, with a solid hierarchy of cardinals, archbishops and bishops, Bohm was an ascetic hermit who would occasionally come in from the wilderness with a compelling message, only to disappear again. Bohmian quantum mechanics is not part of mainstream physics, but for those who do cross over, like John Bell, the commitment can be rewarding. In the post-war 'Un-American Activities' purge, Bohm lost a prestigious job at Princeton and t emporarily his US citizenship, and his nomadic career took him to Brazil, Israel and Bristol before he finally settled in London's Birkbeck College. A sensitive-written book about a gifted, unusual and sometimes provocative figure. The interaction between Bohm and Oppenheimer is especially interesting, while Bohm's later life was bizarre.

  3. David Duke, running for governor, proposes tattooing people with HIV.

    Science.gov (United States)

    1995-05-19

    Former Ku Klux Klan leader, David Duke, planning a second run for governor of Louisiana, said he would curb the AIDS epidemic by tattooing people who are infected with HIV. His suggestion is to put indelible, glow-in-the-dark tattoos on the genitals of people infected with HIV. According to Duke, it may sound very draconian but it would not demean people. He also believes that tattooing would be legal because courts have a history of supporting the quarantining and institutionalizing of people with infectious diseases, such as tuberculosis. Duke said Cuba has had some success in using quarantines to reduce HIV infection, but he does not think it would work in the United States because it would cost too much. According to Duke, many people who get HIV from irresponsible behavior do not tell their partners that they have AIDS--these people are mad at the world and engage in dangerous behaviors even more.

  4. THE SOCIAL THEORY OF LAW CONCEPTION OF DAVID M. TRUBEK

    Directory of Open Access Journals (Sweden)

    Neumalyna Lacerda Alves Dantas Marinho

    2015-12-01

    Full Text Available In this article to study the relationship law, law and development towards a central concept of the theory of modern law, from the work of David M. Trubek. The theory refers to a rational law as a way to achieve development in Third World nations, away from the traditional order, but the host of a modern law. The central conception found intentionality and the universality of the rules and, after empirical analysis, the author proved fundamentally flawed due to its ethnocentric and evolutionism , to believe that developing countries only achieve the full development of importing the legal system of the West. In any case, the studies on the social theory of law contributed to the current concept of law and development.

  5. Masculinity and violence in David Fincher’s "Fight Club"

    Directory of Open Access Journals (Sweden)

    Leire Ituarte Pérez

    2017-12-01

    Full Text Available In this article we address a hermeneutic approach to David Fincher’s Fight Club. Inspired by some of the methodological principles of Psychoanalysis and Queer Theory the study tries to thresh the details of the representation of Masculinity in the film. Departing from the hypothesis that such representation in the film is closely linked to the masculine castration anxiety, the essay traces the recurrent and more or less parodic, more or less subliminal allusions to emasculation as well as the fetishistic compensatory strategies displayed. The analysis concludes that the overwhelming mise en scène of the masculine Oedipal scenario in the film pursues to underpin an hegemonic discourse of Masculinity threatened by the taboo of Homosexuality. Hence, the prominent erotisization of masculine masochism reveals itself, in all its ambivalence, as a performative strategy to institutionalise a heteronormative sexual regime.

  6. A Teoria da Consciência de David Chalmers

    Directory of Open Access Journals (Sweden)

    João de Fernandes Teixeira

    1997-01-01

    Full Text Available O artigo tem por objetivo apresentar e discutir a teoria da consciência elaborada pelo filósofo David Chalmers no seu livro The Conscious Mind, publicado em 1996. O artigo é dividido em duas partes. A primeira expõe os principais delineamentos da teoria de Chalmers; a segunda discute seus principais conceitos, abordando a plausibilidade metafísica da existência dos "zumbis" e a idéia de superveniência.The paper focuses on Chalmer´s theory of consciousness as it is presented in his most recent book, The Conscious Mind, published in 1996. The first part is devoted to a presentation of the main outlines of Chalmer´s theory. The second part discusses such a theory by focusing on the metaphysical plausibility of the existence of zombies as well as on the notion of supervenience.

  7. Conducting interface states at LaInO3/BaSnO3 polar interface controlled by Fermi level

    Science.gov (United States)

    Kim, Useong; Park, Chulkwon; Kim, Young Mo; Shin, Juyeon; Char, Kookrin

    2016-07-01

    We report on a new polar interface state between two band insulators: LaInO3 and BaSnO3, where the sheet conductance enhancement in the interface reaches more than the factor of 104 depending on the La doping concentration in BaSnO3 layer, by monitoring the conductance change before and after the polar interface formation as a function of La doping in BaSnO3. By eliminating the possibilities of oxygen vacancy involvement and cation diffusion, we show that the conductance enhancement is due to electronic reconstruction in the interface. Furthermore, we have found that the interfaces between BaSnO3 and the larger bandgap non-polar perovskites BaHfO3 and SrZrO3 did not show such a conductance enhancement. We discuss a model for the interface state where the Fermi level plays a critical role and the conductance enhancement is due to the existence of polarization in the polar perovskite, LaInO3.

  8. A trigger control system for COMPASS and a measurement of the transverse polarization of Λ and Ξ hyperons from quasi-real photo-production

    CERN Document Server

    Grube, B

    The Trigger Control System of the COMPASS experiment at the CERN SPS distributes the first level trigger together with a unique event identifier and a very precise reference clock, that synchronizes the readout electronics, over a passive optical fiber network to 152 front-end modules. All signals are transmitted over a single optical fiber. The system in addition generates the readout dead-time and provides advanced management functions. The second part presents an analysis of the transverse polarization of L and X hyperons in quasi-real photo-production based on COMPASS data. Averaged over the whole kinematical range the L shows a significantly positive polarization of +3.38 ± 0.32(stat.) ± 0.13(sys.) %. The L exhibits a slightly negative polarization of −1.51 ± 0.39(stat.) ± 0.10(sys.) %. Both polarizations are studied in dependence on the kinematical variables xF, pT, y, and Q2. X− and X + are within the errors unpolarized.

  9. A trigger control system for COMPASS and a measurement of the transverse polarization of Λ and Ξ hyperons from quasi-real photo-production

    International Nuclear Information System (INIS)

    Grube, B.

    2006-01-01

    The Trigger Control System of the COMPASS experiment at the CERN SPS distributes the first level trigger together with a unique event identifier and a very precise reference clock, that synchronizes the readout electronics, over a passive optical fiber network to 152 front-end modules. All signals are transmitted over a single optical fiber. The system in addition generates the readout dead-time and provides advanced management functions. The second part presents an analysis of the transverse polarization of Λ and Ξ hyperons in quasi-real photo-production based on COMPASS data. Averaged over the whole kinematical range the Λ shows a significantly positive polarization of +3.38±0.32(stat.)±0.13(sys.)%. The anti Λ exhibits a slightly negative polarization of -1.51±0.39(stat.)±0.10(sys.)%. Both polarizations are studied in dependence on the kinematical variables x F , p T , y, and Q 2 . Ξ - and anti Ξ + are within the errors unpolarized. (Orig.)

  10. Work plan for the radiological survey for the David Witherspoon, Incorporated, Landfill-1630 site, Knoxville, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This work plan establishes the methods and requirements for performing a radiological survey at the David Witherspoon, Incorporated, Landfill-1630 Site, Knoxville, Tennessee (DWI 1630 Site) in accordance with requirements under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). The radiological survey will identify the radiological contamination level of the equipment and debris stored at the DWI 1630 Site. The data generated from the survey activities will support the decisions for characterization of the equipment/debris and aid in subsequent disposition and waste handling. The survey activities to be performed under this work plan include an equipment radiological survey, a walkover survey, and an immunoassay testing for polychlorinated biphenyls (PCBs). This work plan includes a quality assurance (QA)/quality control (QC) project plan, a health and safety (H&S) plan, and a waste management plan.

  11. David Falk: Algunas cuestiones abiertas para el marketing deportivo. [David Falk: Some open questions for the sports marketing arena].

    Directory of Open Access Journals (Sweden)

    José A. Martínez

    2015-04-01

    Full Text Available David Falk, el que fuera el representante del jugador de baloncesto Michael Jordan, es una figura de referencia para el marketing deportivo. Falk contribuyó decisivamente a revitalizar el marketing deportivo, ayudó a construir lo que probablemente sea la relación comercial más importante del deporte (Jordan-Nike, y llevó hasta el extremo la filosofía de que en la negociación lo importante es que tu cliente llegue a conseguir el máximo dinero posible, más allá de que ese sea su valor de mercado o que el propio mercado pueda admitir esa inflación. En este artículo se repasan algunos de los hechos más destacados de su vida profesional y, desde una perspectiva crítica, se relacionan con varias cuestiones abiertas que el mundo académico y profesional del deporte continúa discutiendo. Abstract David Falk, former agent of the basketball player Michael Jordan, is a figure of reference for sports marketing. Falk was instrumental in revitalizing the sports marketing. He helped to build what is probably the most important relationship in sport business (Jordan-Nike, and strongly defended a radical philosophy of negotiation, where the most important is the maximization of client gains, regardless their true market value or if the market can admit such inflation. This article reviews some of the highlights of his career facts and, from a critical perspective, discusses several open issues related to the academic and professional world of sports. To achieve this aim, several recent contributions to the marketing and sports literature are commented.

  12. David Hume. Una bibliografía de ediciones españolas e iberoamericanas

    OpenAIRE

    Tasset, José Luis

    2011-01-01

    La bibliografía actual sobre David Hume es literalmente inabarcable. Hume Studies a través de la página web de la Hume Society publica anualmente un listado bastante completo de todo lo publicado sobre cualquier aspecto del pensamiento y la vida de David Hume. http://www.humesociety.org/

  13. Queere Aneignungen von David und Goliat : Künstlerische Selbstporträts als besiegte Knabenliebhaber

    NARCIS (Netherlands)

    Hügel, K.; Dietrich, W.; Edenburg, C.; Hugo, P.

    2016-01-01

    Die jüdische Rezeption der biblischen Erzählung von Davids Sieg über Goliat liefert homoerotische Neuinterpretationen dieser Geschichte. Das Verhältnis zwischen Goliat und David wird durch eine erotische Linse als Beziehung eines erwachsenen Manns zu einem schönen jungen Mann gelesen. Die

  14. Building Consensus toward a Shared Purpose: A Profile of President David Gray

    Science.gov (United States)

    Dessoff, Alan

    2011-01-01

    The author presents a profile of APPA president David Gray. One might say that David Gray's path into higher education facilities management was anything but traditional. Today, Gray is the assistant vice president of facilities services at Middle Tennessee State University. His professional career, however, actually began in banking. In 1993 he…

  15. 78 FR 76392 - Hours of Service of Drivers: Application for Exemption; David Muresan

    Science.gov (United States)

    2013-12-17

    ... driver can reset this ``on-duty clock'' to zero by obtaining a period of at least 34-consecutive hours...-0047] Hours of Service of Drivers: Application for Exemption; David Muresan AGENCY: Federal Motor... comments. SUMMARY: FMCSA announces that David Muresan has applied for an exemption from the Agency's hours...

  16. Accuracy and reproducibility of the DAVID SLS-2 scanner in three-dimensional facial imaging

    DEFF Research Database (Denmark)

    Secher, Jesper Jared; Darvann, Tron Andre; Pinholt, Else Marie

    2017-01-01

    PURPOSE: A prospective study was performed to test the accuracy and reproducibility of the DAVID-SLS-2 scanner (SLS-2) [DAVID Vision Systems GmbH], compared to the validated 3dMDtrio scanner (3dMD) [3dMD, LLC, Atlanta, GA, USA]. MATERIALS AND METHODS: The accuracy of the SLS-2 was determined thro...

  17. Planar polarization of Vangl2 in the vertebrate neural plate is controlled by Wnt and Myosin II signaling

    Directory of Open Access Journals (Sweden)

    Olga Ossipova

    2015-07-01

    Full Text Available The vertebrate neural tube forms as a result of complex morphogenetic movements, which require the functions of several core planar cell polarity (PCP proteins, including Vangl2 and Prickle. Despite the importance of these proteins for neurulation, their subcellular localization and the mode of action have remained largely unknown. Here we describe the anteroposterior planar cell polarity (AP-PCP of the cells in the Xenopus neural plate. At the neural midline, the Vangl2 protein is enriched at anterior cell edges and that this localization is directed by Prickle, a Vangl2-interacting protein. Our further analysis is consistent with the model, in which Vangl2 AP-PCP is established in the neural plate as a consequence of Wnt-dependent phosphorylation. Additionally, we uncover feedback regulation of Vangl2 polarity by Myosin II, reiterating a role for mechanical forces in PCP. These observations indicate that both Wnt signaling and Myosin II activity regulate cell polarity and cell behaviors during vertebrate neurulation.

  18. “Silencio”: hearing loss in David Lynch's Mulholland Drive

    Directory of Open Access Journals (Sweden)

    Allister Mactaggart

    2014-11-01

    Full Text Available In a filmmaking career replete with extraordinary images and sounds, David Lynch's Mulholland Drive (2001 stands out for attention as a striking and seemingly inexhaustible resource for analysis. In this article, this film is used to examine the specific ways in which Lynch uses pre-existing pop songs to wrap the spectator within the filmic soundscape. Nowhere is the complexity and uncanniness of pop music made more explicit than in Rebekah Del Rio's stunning performance of “Llorando (Crying” in the Club Silencio scene. The split between the singer's powerful performance and her subsequent collapse with the sound of the voice left hanging in the air marks a pivotal point in the film. This scene, coupled with other examples of feminine jouissance, is contrasted with the deadening roar of the master's voice, which solely demands obedience but is deaf to any reply. At the core of this article is an analysis of the status of the voice (and the gaze as examples of the Lacanian object a and its relationship to Marx's concept of surplus value. Mulholland Drive provides a powerful demonstration of how these concepts can be seen, heard, and felt in relation to film, and how sound can reverberate into the spaces and silences beyond the screen.

  19. Decay of Ethics in David Mamet’s American Buffalo

    Directory of Open Access Journals (Sweden)

    Ehsan Dehghani

    2013-09-01

    Full Text Available The American Dream is a recurrent theme in American literature. In this response, this paper is an attempt to expose the destructive effects of the dream on human spirits and relations and how it is contradicted in different ways through the analysis of his brilliant play, American Buffalo by David Mamet. Beneath the seeming simple surface of the play lies a deep current of meanings that reflect the calamities of modern American life, and in a broader sense, the modern world. This article indicates how capitalism inculcates ideologies in the mind of individuals in order to facilitate the exploiting process and unquestioning subordination. Ragged individualism, as one of these ideologies, disrupts all communal bonds and even exceeds to the disintegration of friendship and family life. On the other hand, this individualism, as an ideology, is sustained by other capitalist ideologies such as advertising, consumerism and emulation. It will also be discussed that monetary interests are all one seeks in a highly competitive atmosphere and nothing is privileged over business ethics. In brief, this reading of the play tries to illuminate that we live in a dream-like world of ideologies that block logical thinking and forge our relationship with our real existence through less suspected ways.

  20. David Malament and the Conventionality of Simultaneity: A Reply

    Science.gov (United States)

    Grünbaum, Adolf

    2010-10-01

    In 1977, David Malament proved the valuable technical result that the simultaneity relation of standard synchrony ɛ=1/2 with respect to an inertial observer O is uniquely definable in terms of the relation κ of causal connectibility. And he claimed that this definability undermines my own version of the conventionality of metrical simultaneity within an inertial frame. But Malament’s proof depends on the imposition of several supposedly “innocuous” constraints on any candidate for the simultaneity relation relative to O. Relying on Allen I. Janis’s 1983 challenge to one of these constraints, I argue that Malament’s technical result did not undermine my philosophical construal of the ontological status of relative metrical simultaneity. Furthermore, I show that (a) Michael Friedman’s peremptorily substantivalist critique of my conception, which Malament endorses, is ill-founded, and (b) if Malament had succeeded in discrediting my own conventionalist version of metrical simultaneity, he would likewise have invalidated Einstein’s pioneering version of it.

  1. David Levi. A Child of the Nineteenth Century

    Directory of Open Access Journals (Sweden)

    Alessandro Grazi

    2015-11-01

    Full Text Available The present paper examines the main biographical traits of the Italian author, politician and Risorgimento activist David Levi (1816-1898. Early in life, Levi abandoned the traditional religious spheres of Judaism but always remained attached to his Jewish heritage, as emerges from his oeuvre. Levi’s relevance derives from his constant effort to amalgamate Italian and Jewish identities in a context of increasing secularity. An analysis of his figure and activities, therefore enables us to investigate some crucial issues at the center of current historiographical debate, such as the nineteenth-century Jewish transition from a traditional to a modern identity, the discussion around the concepts of “assimilation”and “integration,” orientalist researches and the study of religions in nineteenth-century Italy, and the important role of Freemasonry and Saintsimonism in Levi’s secularization modes. In fact, their concept of “Religion of Humanity” helped him to create a synthesis between Enlightenment’s aspirations to universalism and Risorgimento’s cosmopolitan nationalism.

  2. DAVID HUME AND THE CRITICAL EXAMINATION OF EMPIRICISM

    Directory of Open Access Journals (Sweden)

    IONUŢ ŞTEFAN

    2012-11-01

    Full Text Available The research is related to David Hume. This philosopher is described as being an empiricist, but it should be noted that the empiricism promoted by Hume represents the development up to the final consequences of this philosophical doctrine that should be subjected to the observability requirement. The core problem for Hume’s philosophy is the difficulty of causality thinking. The Scottish philosopher promotes a moderate and inconsistent skepticism because he does not doubt the permanency of facts. The Humean epistemology is mixed with elements belonging to some naïve ontology of a materialistic nature and with elements of a sensualistic psychology of an associationist type. The causality or the causal connection between events is based on a psychological belief, which has a pragmatic end for people, in that it offers us the psychological comfort of habitual events and the familiar existential. Causality refers to certain events that have already happened in a certain way, but it cannot constitute a necessary and sufficient basis for similar future events.

  3. Cortical forces and CDC-42 control clustering of PAR proteins for Caenorhabditis elegans embryonic polarization.

    Science.gov (United States)

    Wang, Shyi-Chyi; Low, Tricia Yu Feng; Nishimura, Yukako; Gole, Laurent; Yu, Weimiao; Motegi, Fumio

    2017-08-01

    Cell polarization enables zygotes to acquire spatial asymmetry, which in turn patterns cellular and tissue axes during development. Local modification in the actomyosin cytoskeleton mediates spatial segregation of partitioning-defective (PAR) proteins at the cortex, but how mechanical changes in the cytoskeleton are transmitted to PAR proteins remains elusive. Here we uncover a role of actomyosin contractility in the remodelling of PAR proteins through cortical clustering. During embryonic polarization in Caenorhabditis elegans, actomyosin contractility and the resultant cortical tension stimulate clustering of PAR-3 at the cortex. Clustering of atypical protein kinase C (aPKC) is supported by PAR-3 clusters and is antagonized by activation of CDC-42. Cortical clustering is associated with retardation of PAR protein exchange at the cortex and with effective entrainment of advective cortical flows. Our findings delineate how cytoskeleton contractility couples the cortical clustering and long-range displacement of PAR proteins during polarization. The principles described here would apply to other pattern formation processes that rely on local modification of cortical actomyosin and PAR proteins.

  4. Political polarization

    OpenAIRE

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  5. Political polarization.

    Science.gov (United States)

    Dixit, Avinash K; Weibull, Jörgen W

    2007-05-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  6. DAVID-WS: a stateful web service to facilitate gene/protein list analysis.

    Science.gov (United States)

    Jiao, Xiaoli; Sherman, Brad T; Huang, Da Wei; Stephens, Robert; Baseler, Michael W; Lane, H Clifford; Lempicki, Richard A

    2012-07-01

    The database for annotation, visualization and integrated discovery (DAVID), which can be freely accessed at http://david.abcc.ncifcrf.gov/, is a web-based online bioinformatics resource that aims to provide tools for the functional interpretation of large lists of genes/proteins. It has been used by researchers from more than 5000 institutes worldwide, with a daily submission rate of ∼1200 gene lists from ∼400 unique researchers, and has been cited by more than 6000 scientific publications. However, the current web interface does not support programmatic access to DAVID, and the uniform resource locator (URL)-based application programming interface (API) has a limit on URL size and is stateless in nature as it uses URL request and response messages to communicate with the server, without keeping any state-related details. DAVID-WS (web service) has been developed to automate user tasks by providing stateful web services to access DAVID programmatically without the need for human interactions. The web service and sample clients (written in Java, Perl, Python and Matlab) are made freely available under the DAVID License at http://david.abcc.ncifcrf.gov/content.jsp?file=WS.html.

  7. La economía emprendedora de David Audretsch

    Directory of Open Access Journals (Sweden)

    Maria Callejón

    2009-01-01

    Full Text Available Pocos campos de la Economía cuentan con mejores bases teóricas que la Organización Industrial. Y David Audretsch ha contribuido en gran medida a mejorar el campo de la OI con sus modelos de emprendeduría y, también, con la inspiración y el estímulo que ha infundido a otros académicos. En el artículo publicado en este número monográfico, Audretsch plantea dos conceptos principales: uno es el modelo del filtro del conocimiento; el otro la idea de capital emprendedor. El concepto de filtro del conocimiento es central en la actual discusión sobre la relación entre la generación de conocimiento científico y tecnológico y su grado efectivo de traslación a innovaciones en el mercado. Muestra por qué y cómo los agentes que generan el conocimiento rara vez son los mismos que llegan a comercializarlos. Con frecuencia el puente es un emprendedor. La segunda idea aquí resaltada es el capital emprendedor y cómo la noción se ha popularizado gracias a la publicación de numerosos informes sobre tasas de creación de empresas. En este caso, aunque el concepto teórico sea valioso, ocurre que los estudios empíricos han arrojado pocos y contradictorios resultados.

  8. La economía emprendedora de David Audretsch

    Directory of Open Access Journals (Sweden)

    Maria Callejón

    2009-10-01

    Full Text Available Pocos campos de la Economía cuentan con mejores bases teóricas que la Organización Industrial. Y David Audretsch ha contribuido en gran medida a mejorar el campo de la OI con sus modelos de emprendeduría y, también, con la inspiración y el estímulo que ha infundido a otros académicos. En el artículo publicado en este número monográfico, Audretsch plantea dos conceptos principales: uno es el modelo del filtro del conocimiento; el otro la idea de capital emprendedor. El concepto de filtro del conocimiento es central en la actual discusión sobre la relación entre la generación de conocimiento científico y tecnológico y su grado efectivo de traslación a innovaciones en el mercado. Muestra por qué y cómo los agentes que generan el conocimiento rara vez son los mismos que llegan a comercializarlos. Con frecuencia el puente es un emprendedor. La segunda idea aquí resaltada es el capital emprendedor y cómo la noción se ha popularizado gracias a la publicación de numerosos informes sobre tasas de creación de empresas. En este caso, aunque el concepto teórico sea valioso, ocurre que los estudios empíricos han arrojado pocos y contradictorios resultados.

  9. Polarization measurement in the COMPASS polarized target

    CERN Document Server

    Kondo, K; Baum, G; Berglund, P; Doshita, N; Gautheron, F; Görtz, S; Hasegawa, T; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Yu V; Koivuniemi, J H; Le Goff, J M; Magnon, A; Meyer, W; Reicherz, G; Matsuda, T

    2004-01-01

    Continuous wave nuclear magnetic resonance (NMR) is used to determine the target polarization in the COMPASS experiment. The system is made of the so-called Liverpool Q-meters, Yale-cards, and VME modules for data taking and system controlling. In 2001 the NMR coils were embedded in the target material, while in 2002 and 2003 the coils were mounted on the outer surface of the target cells to increase the packing factor of the material. Though the error of the measurement became larger with the outer coils than with the inner coils, we have performed stable measurements throughout the COMPASS run time for 3 years. The maximum polarization was +57% and -53% as the average in the target cells.

  10. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  11. Controlling Surface Morphology and Circumventing Secondary Phase Formation in Non-polar m-GaN by Tuning Nitrogen Activity

    Science.gov (United States)

    Chang, C. W.; Wadekar, P. V.; Guo, S. S.; Cheng, Y. J.; Chou, M.; Huang, H. C.; Hsieh, W. C.; Lai, W. C.; Chen, Q. Y.; Tu, L. W.

    2018-01-01

    For the development of non-polar nitrides based optoelectronic devices, high-quality films with smooth surfaces, free of defects or clusters, are critical. In this work, the mechanisms governing the topography and single phase epitaxy of non-polar m-plane gallium nitride ( m-GaN) thin films are studied. The samples were grown using plasma-assisted molecular beam epitaxy on m-plane sapphire substrates. Growth of pure m-GaN thin films, concomitant with smooth surfaces is possible at low radio frequency powers and high growth temperatures as judged by the high resolution x-ray diffraction, field emission scanning electron microscopy, and atomic force microscopy measurements. Defect types and densities are quantified using transmission electron microscopy, while Raman spectroscopy was used to analyze the in-plane stress in the thin films which matches the lattice mismatch analysis. Energy dispersive spectroscopy and cathodoluminescence support a congruent growth and a dominant near band edge emission. From the analysis, a narrow growth window is discovered wherein epitaxial growth of pure m-plane GaN samples free of secondary phases with narrow rocking curves and considerable smooth surfaces are successfully demonstrated.

  12. Zeeman- and electric-field control of spin- and valley-polarized transport through biased magnetic junctions on WSe2

    Science.gov (United States)

    Tahir, M.; Krstajić, P. M.; Vasilopoulos, P.

    2017-04-01

    The electronic properties of WSe2 comprise a huge spin-orbit coupling, a wide direct band gap, and especially a strong anisotropic lifting of the degeneracy of the valley degree of freedom in a magnetic field. We study ballistic electron transport through single or double junctions on monolayer WSe2 in the presence of spin M s and valley M v Zeeman fields and of an electric potential U. The conductance vs. the field M s or M v decreases in a fluctuating manner. For a single junction the spin P s and valley P v polarizations rise with M=M_v=2Ms , reach a value of more than 70%, and become perfect above U≈ 90 \\text{meV} while for a double junction this change can occur for U≈ 50 \\text{meV} and M≥ 10 \\text{meV} . P v increases with U and both polarizations oscillate with the junction width. The results may render WSe2 a promising candidate for new spintronic and valleytronic devices.

  13. Magnetic and electric control of spin- and valley-polarized transport across tunnel junctions on monolayer WSe2

    Science.gov (United States)

    Tahir, M.; Krstajić, P. M.; Vasilopoulos, P.

    2017-06-01

    The recent experimental realization of high-quality WSe2 leads to the possibility of an efficient manipulation of its spin and valley degrees of freedom. Its electronic properties comprise a huge spin-orbit coupling, a direct band gap, and a strong anisotropic lifting of the degeneracy of the valley degree of freedom in a magnetic field. We evaluate its band structure and study ballistic electron transport through single and double junctions (or barriers) on monolayer WSe2 in the presence of spin Ms and valley Mv Zeeman fields and of an electric potential U . The conductance versus the field Ms or Mv decreases in a fluctuating manner. For a single junction, the spin Ps and valley Pv polarizations rise with M =Mv=2 Ms , reach a value of more than 55 % , and become perfect above U ≈45 meV while for a double junction this change can occur for U ≥50 meV and M ≥5 meV. In certain regions of the (M ,U ) plane Pv becomes perfect. The conductance gc, its spin-up and spin-down components, and both polarizations oscillate with the barrier width d . The ability to isolate various carrier degrees of freedom in WSe2 may render it a promising candidate for new spintronic and valleytronic devices.

  14. Osborne's trilogy : a critique of the management philosophy of David Osborne / Jan-Erik Lane

    Index Scriptorium Estoniae

    Lane, Jan-Erik

    2006-01-01

    Kriitiline lühiülevaade David Osborne'i raamatutes Reinventing government (kaasautor T. Gaebler, 1992), Banishing bureaucracy (kaasautor P. Plastrik, 1997) ja The price of government (kaasautor P. Hutchinson, 2004) avaldatud teooriatest

  15. Clinton või Trump - USA jaoks ühtviisi katastroof / David Satter ; intervjueerinud Taavi Minnik

    Index Scriptorium Estoniae

    Satter, David

    2016-01-01

    Intervjuu maineka Ühendriikide Venemaa eksperdi David Satteriga, kes hoiatab, et Ameerika presidendivalimistel on inimestel valida kahe äärmiselt halva kandidaadi - Donald Trumpi ning Hillary Clintoni vahel

  16. Jalutu David tantsib auhinna vääriliselt / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2006-01-01

    Tantsufilm "Elu hind" ("The Cost of Living") : lavastaja ja koreograaf Lloyd Newson : peaosades David Toole, Eddie Kay : Suurbritannia 2004. Filmi aluseks on Londoni tantsuteatri DV 8 Physical Theatre' 2000.a. valminud lavastus

  17. Prozaci asemel GTD ehk getting things done / David Allen ; interv. Endrik Randoja

    Index Scriptorium Estoniae

    Allen, David

    2007-01-01

    Konsultant ja koolitaja David Allen oma aja- ja enesejuhtimise meetodist GTD - getting things done. Vt. samas: Väikesed nipid, et tõhusam olla; Milles seisneb Alleni meetod; Kuidas ma oma ülesannet täitsin - logiraamat

  18. "Handbook of biomedical optics", edited by David A. Boas, Constantinos Pitris, and Nimmi Ramanujam

    Science.gov (United States)

    2012-01-01

    David A. Boas, Constantinos Pitris, and Nimmi Ramanujam, Eds.: Handbook of Biomedical Optics CRC Press, Taylor and Francis Group, Boca Raton, London, New York, 2011 ISBN: 978-1-4200-9036-9 (Hardback), 787 pages

  19. "Handbook of biomedical optics", edited by David A. Boas, Constantinos Pitris, and Nimmi Ramanujam

    OpenAIRE

    Gramatikov Boris

    2012-01-01

    Abstract David A. Boas, Constantinos Pitris, and Nimmi Ramanujam, Eds.: Handbook of Biomedical Optics CRC Press, Taylor and Francis Group, Boca Raton, London, New York, 2011 ISBN: 978-1-4200-9036-9 (Hardback), 787 pages

  20. Anneli Remme soovitab : David Oistrahhi festival. Koorifestival Pärnus / Anneli Remme

    Index Scriptorium Estoniae

    Remme, Anneli, 1968-

    2002-01-01

    David Oistrahhi festivalist 14. juulini Pärnu Eliisabeti kirikus, Teatris Endla, Ammende villas, Eesti Õigeusu kirikus ja Pärnu Raekojas. Festivali kunstiline juht Allar Kaasik. Pärnu koorifestivalist

  1. Robert Bresson, Mariano Barroso, Paskaljevich, Mary Harron, David Trueba, Lars von Trier, Liv Ullmann, Zhang Yimou

    OpenAIRE

    La madriguera

    2000-01-01

    La madriguera (2000). Robert Bresson, Mariano Barroso, Paskaljevich, Mary Harron, David Trueba, Lars von Trier, Liv Ullmann, Zhang Yimou. Ediciones de intervención cultural S.L. http://hdl.handle.net/10251/41911. 80 80 33

  2. Siim Nestor soovitab : David Morales. Reede ja laupäeva parimad palad / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2004-01-01

    Popmuusikaüritustest: David Morales 15. apr. klubis Moskva, "Eklekter" 16. apr Von Krahlis (esinejaks rootsi diskor DJ Mad Mats), prantsuse diskor DJ Yellow 16. apr. klubis Hollywood, üritusest "Dependent" 17. apr. Tartus

  3. David Oistrahhi festival läheneb lõpule / Toivo Traks

    Index Scriptorium Estoniae

    Traks, Toivo

    2006-01-01

    Kontsertidest David Oistrahhi festivali raames: saksa viola da gamba mängija Holger Faust-Peters ja klavessinist Iren Lill 19. juulil Pärnu Eliisabeti kirikus, briti laulja Patricia Rozario ja RTE Vanbrugh Quartet 20. juulil Eliisabeti kirikus

  4. Miks meil on kogu aeg kiire? / David Allen ; interv. Endrik Randoja

    Index Scriptorium Estoniae

    Allen, David

    2006-01-01

    Produktiivsuse ekspert vastab küsimustele ettevõetud tegevuste tulemuslikumalt lõpule viimise kohta. Lisa: Aja paremaks kasutamiseks pakub David Allen lisaks veel kolm tõhusat ja lihtsasti rakendatavat põhimõtet

  5. [David Feest. Zwangskollektivierung im Baltikum : die Sowjetisierung des estnischen Dorfes 1944-1953] / Anu Mai Kõll

    Index Scriptorium Estoniae

    Kõll, Anu Mai, 1946-

    2008-01-01

    Arvustus: Feest, David. Zwangskollektivierung im Baltikum : die Sowjetisierung des estnischen Dorfes 1944-1953. Köln [etc.] : Böhlau, 2007. Esimesest rahvusvaheliselt kättesaadavast laiahaardelisest Eesti kollektiviseerimist käsitlevast teosest

  6. Controllable Release of Interleukin-4 in Double-Layer Sol-Gel Coatings on TiO2 Nanotubes for Modulating Macrophage Polarization.

    Science.gov (United States)

    Li, Mengting; Gao, LIli; Chen, Junhong; Zhang, Yan; Wang, Jianxin; Lu, Xiong; Duan, Ke; Weng, Jie; Feng, Bo

    2017-10-23

    Classically activated M1 macrophages and alternatively activated M2 macrophages play key roles in regulating immune responses. M1 macrophages initiate angiogenesis in the early stages of wound healing or after implantation. However, their prolonged activation can lead to chronic inflammation. We speculated that biomedical implants with specific properties can induce a shift from M1 to M2 macrophages at a specific time point to promote tissue repair and wound healing. To investigate this possibility, drug-loaded double-layer sol-gel coatings were fabricated on TiO2 nanotubes (TNTs), which were used to modulate the switch from the M1 to the M2 phenotype by controlled release of interleukin (IL)-4. The lower sol-gel layer with IL-4 consisted of a carboxymethyl chitosan (CMCS) hydrogel, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and N-hydroxysuccinimide as a crosslinker (IL4/TNT). The upper layer fabricated on the IL4/TNT sample was another type of CMCS hydrogel that used genipin (GP) as a crosslinker (GP/IL4/TNT). We found that IL-4 was released from GP/IL4/TNTs in a controlled manner, with the greatest release occurring after 72 h. GP/IL4/TNT stimulated the polarization of macrophages from the M1 to M2 phenotype after the macrophage polarization from the M0 to M1 phenotype. This provides a template for the fabrication of biomaterials that can direct macrophage polarization and stimulate tissue regeneration following the initial inflammatory response to implants. . © 2017 IOP Publishing Ltd.

  7. On Territorial Justice, Human Flourishing and Geographical Strategies of Liberation An Interview with David Harvey

    OpenAIRE

    Harvey , David; Dufaux , Frédéric; Gervais-Lambony , Philippe; Buire , Chloé; Desbois , Henri

    2011-01-01

    International audience; An interview of David Harvey (CUNY) with the Journal justice spatiale - spatial justice (Frédéric Dufaux, Philippe Gervais-Lambony, Chloé Buire, Henri Desbois), Laboratoire Gecko and Laboratoire Mosaïques (UMR LAVUE) in Nanterre, on the 21th of November 2011. The transcript of the interview is online, on the Journal’s site, with its French translation: panouissement-humain-et-strategies-geographiques-de-liberation-un-entretien-avec-david-harvey/

  8. [Jaan Kross ja David Samoilov. Mu sõbra avatud akna all] / M. J.

    Index Scriptorium Estoniae

    Jõgi, Mall, 1947-

    2016-01-01

    Tutvustus: Kross, Jaan. Mu sõbra avatud akna all : [luuletused ja tõlked] = В окно моего друга : [стихи и переводы] / Jaan Kross ja David Samoilov ; Tallinna Ülikool. Tallinn : Avenarius, 2015 ; David Samoilovi Pärnu : teejuht. Luuletusi. Tallinn : Avenarius, 2015

  9. Polarization-Dependent Multi-Functional Metamaterial as Polarization Filter, Transparent Wall and Circular Polarizer using Ring-Cross Resonator

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2017-09-01

    Full Text Available We propose a polarization-dependent multi-functional metamaterial using ring-cross resonator. Based on the analysis of surface current distributions induced by different polarized incidence, we demonstrate that the proposed metamaterial serves as a polarization filter, a transparent wall and a circular polarizer under different polarization normal incidence. Additionally, parameter analyses on the control of resonance are discussed to complementally explain the physical origin. Simulated results show that the proposed metamaterial functions as a polarization filter eliminating the x-polarization wave at 10.1 GHz and y-polarization wave at 14.3 GHz, a transparent wall transmitting both x-polarized and y-polarized incident waves at 12.6 GHz, and a broadband circular polarizer converting the +45° polarized (-45° polarized incident wave to the left (right handed circularly polarized wave from 10.8 to 12.8 GHz, respectively. Measured results agree well with the simulation and validate the performance of the proposed multifunctional metamaterial.

  10. Configuration Manual Polarized Proton Collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Svirida, D.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.

    2006-01-01

    In this report we present our design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. We provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  11. CONFIGURATION MANUAL POLARIZED PROTON COLLIDER AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.; MACKAY,W.W.; ALEKSEEV,I.; BAI,M.; BROWN,K.; BUNCE,G.; CAMERON,P.; COURANT,E.; ET AL.

    2001-03-01

    In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  12. Quantum control of molecular vibrational and rotational excitations in a homonuclear diatomic molecule: A full three-dimensional treatment with polarization forces

    Science.gov (United States)

    Ren, Qinghua; Balint-Kurti, Gabriel G.; Manby, Frederick R.; Artamonov, Maxim; Ho, Tak-San; Rabitz, Herschel

    2006-01-01

    The optimal control of the vibrational excitation of the hydrogen molecule [Balint-Kurti et al., J. Chem. Phys. 122, 084110 (2005)] utilizing polarization forces is extended to three dimensions. The polarizability of the molecule, to first and higher orders, is accounted for using explicit ab initio calculations of the molecular electronic energy in the presence of an electric field. Optimal control theory is then used to design infrared laser pulses that selectively excite the molecule to preselected vibrational-rotational states. The amplitude of the electric field of the optimized pulses is restricted so that there is no significant ionization during the process, and a new frequency sifting method is used to simplify the frequency spectrum of the pulse. The frequency spectra of the optimized laser pulses for processes involving rotational excitation are more complex than those relating to processes involving only vibrational excitation.

  13. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  14. Integrins and epithelial cell polarity.

    Science.gov (United States)

    Lee, Jessica L; Streuli, Charles H

    2014-08-01

    Cell polarity is characterised by differences in structure, composition and function between at least two poles of a cell. In epithelial cells, these spatial differences allow for the formation of defined apical and basal membranes. It has been increasingly recognised that cell-matrix interactions and integrins play an essential role in creating epithelial cell polarity, although key gaps in our knowledge remain. This Commentary will discuss the mounting evidence for the role of integrins in polarising epithelial cells. We build a model in which both inside-out signals to polarise basement membrane assembly at the basal surface, and outside-in signals to control microtubule apical-basal orientation and vesicular trafficking are required for establishing and maintaining the orientation of epithelial cell polarity. Finally, we discuss the relevance of the basal integrin polarity axis to cancer. This article is part of a Minifocus on Establishing polarity. © 2014. Published by The Company of Biologists Ltd.

  15. Research on generating various polarization-modes in polarized illumination system

    Science.gov (United States)

    Huang, Jinping; Lin, Wumei; Fan, Zhenjie

    2013-08-01

    With the increase of the numerical aperture (NA), the polarization of light affects the imaging quality of projection lens more significantly. On the contrary, according to the mask pattern, the resolution of projection lens can be improved by using the polarized illumination. That is to say, using the corresponding polarized beam (or polarization-mode) along with the off-axis illumination will improve the resolution and the imaging quality of the of projection lens. Therefore, the research on the generation of various polarization modes and its conversion methods become more and more important. In order to realize various polarization modes in polarized illumination system, after read a lot of references, we provide a way that fitting for the illumination system with the wavelength of 193nm.Six polarization-modes and a depolarized mode are probably considered. Wave-plate stack is used to generate linearly polarization-mode, which have a higher degree polarization. In order to generate X-Y and Y-X polarization mode, the equipment consisting of four sectors of λ/2 wave plate was used. We combined 16 sectors of λ/2 wave plate which have different orientations of the "slow" axis to generate radial and azimuthal polarization. Finally, a multi-polarization control device was designed. Using the kind of multi-polarization control device which applying this method could help to choose the polarization modes conveniently and flexibility for the illumination system.

  16. Photoionization of water molecules by a train of attosecond pulses assisted by a near-infrared laser: delay and polarization control

    Science.gov (United States)

    Martini, Lara; Boll, Diego I. R.; Fojón, Omar A.

    2017-08-01

    Basic reactions involving water molecules are essential to understand the interaction between radiation and the biological tissue because living cells are composed mostly by water. Therefore, the knowledge of ionization of the latter is crucial in many domains of Biology and Physics. So, we study theoretically the photoionization of water molecules by extreme ultraviolet attopulse trains assisted by lasers in the near-infrared range. We use a separable Coulomb-Volkov model in which the temporal evolution of the system can be divided into three stages allowing spatial and temporal separation for the Coulomb and Volkov final state wavefunctions. First, we analyze photoelectron angular distributions for different delays between the attopulse train and the assistant laser field. We compare our results for water and Ne atoms as they belong to the same isoelectronic series. Moreover, we contrast our calculations with previous theoretical and experimental work for Ar atoms due to the similarities of the orbitals involved in the reaction. Second, we study the effect of varying the relative orientations of the attopulse and laser field polarizations and we compare our predictions with other theories and experiments. We expect these studies contribute to the improvement of polarization experiments and the development of the attopulse trains and assistant laser fields technologies. Finally, we hope our work promote progress on the control of the chemical reactivity of water molecules since this could be useful in different fields such as radiobiology and medical physics.

  17. Control of threshold enhancements in harmonic generation by atoms in a two-color laser field with orthogonal polarizations

    Science.gov (United States)

    Starace, Anthony F.; Frolov, M. V.; Manakov, N. L.; Sarantseva, T. S.; Silaev, A. A.; Vvedenskii, N. V.

    2017-04-01

    Threshold phenomena (or channel-closing effects) are analyzed in high-order harmonic generation (HHG) by atoms in a two-color laser field with orthogonal linearly polarized components of a fundamental field and its second harmonic. We show that the threshold behavior of HHG rates for the case of a weak second harmonic component is sensitive to the parity of a closing multiphoton ionization channel and the spatial symmetry of the initial bound state of the target atom, while for the case of comparable intensities of both components, suppression of threshold phenomena is observed as the relative phase between the components of a two-color field varies. A quantum orbit analysis as well as phenomenological considerations in terms of Baz' theory of threshold phenomena are presented in order to describe and explain the major features of threshold phenomena in HHG by a two-color field. Work supported in part by NSF Grant No. PHYS-1505492 (AFS), by Russian Science Foundation Grant No. 15-12-10033 (MVF, TSS, AAS, NVV), and by the Ministry of Education & Science of the Russian Federation Project No. 1019 (NLM).

  18. [Lessons learned from Magen David Adom's activities during the 2nd Lebanon War].

    Science.gov (United States)

    Rafalowski, Chaim; Peleg, Kobi; Bin, Eli

    2010-07-01

    The activities of Magen David Adom (MDA) during the 2nd Lebanese War led to a series of conclusions (some established during the fighting) regarding the operational concept of the organization, the response to the needs of the team members, and the resource requirements. The fighting led to an update in the operational concept, moving to the smaller based operational unit--the station, creating a flexible concept, enabling response to various simultaneous scenes, quickly generating a common situational awareness, and relocation of resources to the more relevant events. TechnoLogy must support the operational concept. The response to stress-related victims should be part of the operational concept during conflict. Debriefing and learning processes are part of the response and enable adaptation to the changing reality. A comprehensive response to the needs of the team members is required, by relocation of family members, meeting the daily needs and preventing stress-related reactions among them. A rotation of leave of absence, central management of human resources and the management of volunteers--spontaneous and those who return to active work, are other components of this issue. The required resources--personal protective equipment, collective protection, command control and communications equipment, the supplies level and the different vehicles required for the operation, are important issues in the operational program of the organization. Collecting blood, maintaining a strategic stockpile and protecting the units, are all part of MDA missions.

  19. Deterministic photonic spatial-polarization hyper-controlled-not gate assisted by a quantum dot inside a one-side optical microcavity

    International Nuclear Information System (INIS)

    Ren, Bao-Cang; Wei, Hai-Rui; Deng, Fu-Guo

    2013-01-01

    To date, all work concerning the construction of quantum logic gates, an essential part of quantum computing, has focused on operating in one degree of freedom (DOF) for quantum systems. Here, we investigate the possibility of achieving scalable photonic quantum computing based on two DOFs for quantum systems. We construct a deterministic hyper-controlled-not (hyper-CNOT) gate operating in both the spatial mode and polarization DOFs for a photon pair simultaneously, using the giant optical Faraday rotation induced by a single-electron spin in a quantum dot inside a one-side optical microcavity as a result of cavity quantum electrodynamics. With this hyper-CNOT gate and linear optical elements, two-photon four-qubit cluster entangled states can be prepared and analyzed, which give an application to manipulate more information with less resources. We analyze the experimental feasibility of this hyper-CNOT gate and show that it can be implemented with current technology. (letter)

  20. Precessing deuteron polarization

    International Nuclear Information System (INIS)

    Sitnik, I.M.; Volkov, V.I.; Kirillov, D.A.; Piskunov, N.M.; Plis, Yu.A.

    2002-01-01

    The feasibility of the acceleration in the Nuclotron of deuterons polarized in the horizontal plane is considered. This horizontal polarization is named precessing polarization. The effects of the main magnetic field and synchrotron oscillations are included. The precessing polarization is supposed to be used in studying the polarization parameters of the elastic dp back-scattering and other experiments

  1. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 2, Appendixes

    International Nuclear Information System (INIS)

    1996-10-01

    This document contains the appendixes for the remedial investigation and feasibility study for the David Witherspoon, Inc., 901 site in Knoxville, Tennessee. The following topics are covered in the appendixes: (A) David Witherspoon, Inc., 901 Site Historical Data, (B) Fieldwork Plans for the David Witherspoon, Inc., 901 Site, (C) Risk Assessment, (D) Remediation Technology Discussion, (E) Engineering Support Documentation, (F) Applicable or Relevant and Appropriate Requirements, and (G) Cost Estimate Documentation

  2. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 2, Appendixes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This document contains the appendixes for the remedial investigation and feasibility study for the David Witherspoon, Inc., 901 site in Knoxville, Tennessee. The following topics are covered in the appendixes: (A) David Witherspoon, Inc., 901 Site Historical Data, (B) Fieldwork Plans for the David Witherspoon, Inc., 901 Site, (C) Risk Assessment, (D) Remediation Technology Discussion, (E) Engineering Support Documentation, (F) Applicable or Relevant and Appropriate Requirements, and (G) Cost Estimate Documentation.

  3. Polare maskuliniteter

    Directory of Open Access Journals (Sweden)

    Marit Anne Hauan

    2012-05-01

    Full Text Available In this paper my aim is to read and understand the journal of Gerrit de Veer from the last journey of William Barents to the Arctic Regions in 1596 and the journal of captain Junge on his hunting trip from Tromsø to Svalbard in 1834.It is nearly 240 years between this to voyages. The first journal is known as the earliest report from the arctic era. Gerrit de Veer adds instructive copper engravings to his text and give us insight in the crews meeting with this new land. Captain Junges journal is found together with his dead crew in a house in a fjord nearby Ny-Ålesund and has no drawings, but word. Both of these journals may be read as sources of the knowledge and understanding of the polar region. They might also unveil the ideas of how to deal with and survive under the challenges that is given. In addition one can ask if the sources can tell us more about how men describe their challenges. Can the way they expressed themselves in the journals give us an understanding of masculinity? And not least help us to create good questions of the change in the ideas of masculinities which is said to follow the change in understanding of the wilderness.

  4. Hebrews 5:7 as the cry of the Davidic sufferer

    Directory of Open Access Journals (Sweden)

    Timothy Bertolet

    2017-10-01

    Full Text Available This article proposes a better source for the Son’s cry in Hebrews 5:7. It begins by surveying sources previous scholars have identified, including Jesus’ cry in Gethsemane and Golgotha, several Psalms, and the Maccabean martyr literature. It is then argued that these background sources for the language are insufficient. Instead the author of Hebrews has an entire motif from the Psalter as his informing source: the Davidic figure that cries out in trust to be delivered from a death-like experience. Firstly, the motif of the Davidic righteous suffering in the LXX Psalms is demonstrated. Secondly, Hebrews’ use of the Messianic royal figure is demonstrated and thirdly, Hebrews 5:7 as a portrait of the Christ who cries out for deliverance is demonstrated. Thus, Hebrews 5:7 sees the Son as the Davidic king who is the true representative human exercising trust in YHWH, bringing to fulfilment the theme from various Psalms.

  5. When Shakespeare met Raimi: David Mence’s Macbeth re-arisen

    Directory of Open Access Journals (Sweden)

    Ruben Benatti

    2017-11-01

    Full Text Available What would happen if Macbeth returned as a zombie? David Mence's "Macbeth Re-Arisen", a daring sequel of Shakespeare's Macbeth, is the answer to that question. According to award-winning author David Mence, the borders between pulp science fiction, fantasy and horror and literary fiction are more permeable than we think (Mence, 2014. In his audacious "Macbeth Re-Arisen", entirely written in blank verse, Mence blends the medieval Scotland depicted by Shakespeare with the maniacal zombies of Sam Raimi's "Evil Dead" series. This article analyses the representation of zombies as characters in relation to David Mence's "Macbeth Re-Arisen", showing some continuity between this sequel of Shakespeares "Macbeth" and zombies in cinema, popular culture, and social studies. This article also analyses characters and topoi in ÒMacbeth Re-ArisenÓ and compares them to those in Shakesperare's "Macbeth".

  6. Effects of high-intensity pulse irradiation with linear polarized near-infrared rays and stretching on muscle tone in patients with cerebrovascular disease: a randomized controlled trial.

    Science.gov (United States)

    Takeuchi, Nobuyuki; Takezako, Nobuhiro; Shimonishi, Yuko; Usuda, Shigeru

    2017-08-01

    [Purpose] The purpose of this study was to clarify the influence of high-intensity pulse irradiation with linear polarized near-infrared rays (HI-LPNR) and stretching on hypertonia in cerebrovascular disease patients. [Subjects and Methods] The subjects were 40 cerebrovascular disease patients with hypertonia of the ankle joint plantar flexor muscle. The subjects were randomly allocated to groups undergoing treatment with HI-LPNR irradiation (HI-LPNR group), stretching (stretching group), HI-LPNR irradiation followed by stretching (combination group), and control group (10 subjects each). In all groups, the passive range of motion of ankle dorsiflexion and passive resistive joint torque of ankle dorsiflexion were measured before and after the specified intervention. [Results] The changes in passive range of motion, significant increase in the stretching and combination groups compared with that in the control group. The changes in passive resistive joint torque, significant decrease in HI-LPNR, stretching, and combination groups compared with that in the control group. [Conclusion] HI-LPNR irradiation and stretching has effect of decrease muscle tone. However, combination of HI-LPNR irradiation and stretching has no multiplier effect.

  7. David C. Drum, DC, FCCS(C): an accomplished, multi-faceted individual.

    Science.gov (United States)

    Brown, Douglas M

    2017-03-01

    Pablo Picasso (1881-1973) is quoted as saying, "The meaning of life is to find your gift. The purpose of life is to give it away." With these few words Picasso captures the essence of David Drum's existence. From his birth in Moncton, NB, through his formal education in Toronto, ON, to his so-called "retirement" in Crystal Beach, ON, this paper spans 72 years, unveiling the broad range of opportunities for growth David Drum has encountered in his life's journey and documenting his acceptance of the obligations for proud philanthropy that accompany them. Dr. Drum's many accomplishments, gifts, and contributions to the profession and world of art are discussed.

  8. David I reimplantation procedure for aortic root replacement in Marfan patients: medium-term outcome.

    Science.gov (United States)

    Kari, Fabian A; Beyersdorf, Friedhelm; Rylski, Bartosz; Stephens, Elizabeth H; Russe, Maximilian; Siepe, Matthias

    2014-11-01

    Technical variations of the David reimplantation valve-sparing aortic root replacement (V-SARR) procedure have been proposed to be advantageous in patients with connective tissue disease, such as the Marfan syndrome (MFS). We report results of a Marfan cohort treated exclusively with the non-modified David I procedure. Forty-eight Marfan patients (25 males, mean age 33 ± 12 years, range 15-62 years) underwent the original variant of the David V-SARR (David I) between 1997 and 2013. Forty-two operations (88%) were performed as elective procedures for aortic root aneurysms and six for acute dissections (12%). Seventeen had aortic regurgitation (AR) grades ≥2+ preoperatively, and 3 had AR >2+. No patients with severe AR (4+) were selected for V-SARR. Three full or hemi-arch replacements were performed. Patients who were operated on using a variation of the David I or David II procedure were excluded. Mean prosthesis size was 28 ± 3 mm (18-30 mm). Mean clinical and echocardiographic follow-up (98% complete) was 3.8 ± 3.7 years with a cumulative follow-up of 178 patient-years. The early mortality rate was 2% (one hospital death). The survival rate was 98% (95% confidence 84-99%) at 4 years and 90% (57-98%) at 8 years with 5 patients at risk at 10 years. The rate of freedom from root or valve reoperation was 97% (79-99%) and 97% (79-99%) at 4 and 8 years, respectively. Only one patient required mechanical aortic valve replacement for progression of AR. Despite potential theoretical drawbacks of the David I V-SARR technique without neo-sinuses or a neo-sinotubular junction, it results in a favourable mid-term outcome in Marfan patients and compares well with reported results of different modifications of David V-SARR. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  9. Anodic Concentration Polarization in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Williford, Rick E.; Chick, Lawrence A.; Maupin, Gary D.; Simner, Steve P.; Stevenson, Jeffry W.; Khaleel, Mohammad A.; Wachsman, ED, et al

    2003-08-01

    Concentration polarization is important because it determines the maximum power output of a solid oxide fuel cell (SOFC) at high fuel utilization. Anodic concentration polarization occurs when the demand for reactants exceeds the capacity of the porous ceramic anode to supply them by gas diffusion mechanisms. High tortuosities (bulk diffusion resistances) are often assumed to explain this behavior. However, recent experiments show that anodic concentration polarization originates in the immediate vicinity of the reactive triple phase boundary (TPB) sites near the anode/electrolyte interface. A model is proposed to describe how concentration polarization is controlled by two localized phenomena: competitive adsorption of reactants in areas adjacent to the reactive TPB sites, followed by relatively slow surface diffusion to the reactive sites. Results suggest that future SOFC design improvements should focus on optimization of the reactive area, adsorption, and surface diffusion at the anode/electrolyte interface.

  10. Mechanical writing of ferroelectric polarization.

    Science.gov (United States)

    Lu, H; Bark, C-W; Esque de los Ojos, D; Alcala, J; Eom, C B; Catalan, G; Gruverman, A

    2012-04-06

    Ferroelectric materials are characterized by a permanent electric dipole that can be reversed through the application of an external voltage, but a strong intrinsic coupling between polarization and deformation also causes all ferroelectrics to be piezoelectric, leading to applications in sensors and high-displacement actuators. A less explored property is flexoelectricity, the coupling between polarization and a strain gradient. We demonstrate that the stress gradient generated by the tip of an atomic force microscope can mechanically switch the polarization in the nanoscale volume of a ferroelectric film. Pure mechanical force can therefore be used as a dynamic tool for polarization control and may enable applications in which memory bits are written mechanically and read electrically.

  11. Mechanical Writing of Ferroelectric Polarization

    Science.gov (United States)

    Lu, H.; Bark, C.-W.; Esque de los Ojos, D.; Alcala, J.; Eom, C. B.; Catalan, G.; Gruverman, A.

    2012-04-01

    Ferroelectric materials are characterized by a permanent electric dipole that can be reversed through the application of an external voltage, but a strong intrinsic coupling between polarization and deformation also causes all ferroelectrics to be piezoelectric, leading to applications in sensors and high-displacement actuators. A less explored property is flexoelectricity, the coupling between polarization and a strain gradient. We demonstrate that the stress gradient generated by the tip of an atomic force microscope can mechanically switch the polarization in the nanoscale volume of a ferroelectric film. Pure mechanical force can therefore be used as a dynamic tool for polarization control and may enable applications in which memory bits are written mechanically and read electrically.

  12. Controlling the stoichiometry and strand polarity of a tetramolecular G-quadruplex structure by using a DNA origami frame

    Science.gov (United States)

    Rajendran, Arivazhagan; Endo, Masayuki; Hidaka, Kumi; Lan Thao Tran, Phong; Mergny, Jean-Louis; Sugiyama, Hiroshi

    2013-01-01

    Guanine-rich oligonucleotides often show a strong tendency to form supramolecular architecture, the so-called G-quadruplex structure. Because of the biological significance, it is now considered to be one of the most important conformations of DNA. Here, we describe the direct visualization and single-molecule analysis of the formation of a tetramolecular G-quadruplex in KCl solution. The conformational changes were carried out by incorporating two duplex DNAs, with G–G mismatch repeats in the middle, inside a DNA origami frame and monitoring the topology change of the strands. In the absence of KCl, incorporated duplexes had no interaction and laid parallel to each other. Addition of KCl induced the formation of a G-quadruplex structure by stably binding the duplexes to each other in the middle. Such a quadruplex formation allowed the DNA synapsis without disturbing the duplex regions of the participating sequences, and resulted in an X-shaped structure that was monitored by atomic force microscopy. Further, the G-quadruplex formation in KCl solution and its disruption in KCl-free buffer were analyzed in real-time. The orientation of the G-quadruplex is often difficult to control and investigate using traditional biochemical methods. However, our method using DNA origami could successfully control the strand orientations, topology and stoichiometry of the G-quadruplex. PMID:23863846

  13. Injection-modulated polarity conversion by charge carrier density control via a self-assembled monolayer for all-solution-processed organic field-effect transistors

    Science.gov (United States)

    Roh, Jeongkyun; Lee, Taesoo; Kang, Chan-Mo; Kwak, Jeonghun; Lang, Philippe; Horowitz, Gilles; Kim, Hyeok; Lee, Changhee

    2017-04-01

    We demonstrated modulation of charge carrier densities in all-solution-processed organic field-effect transistors (OFETs) by modifying the injection properties with self-assembled monolayers (SAMs). The all-solution-processed OFETs based on an n-type polymer with inkjet-printed Ag electrodes were fabricated as a test platform, and the injection properties were modified by the SAMs. Two types of SAMs with different dipole direction, thiophenol (TP) and pentafluorobenzene thiol (PFBT) were employed, modifying the work function of the inkjet-printed Ag (4.9 eV) to 4.66 eV and 5.24 eV with TP and PFBT treatments, respectively. The charge carrier densities were controlled by the SAM treatment in both dominant and non-dominant carrier-channel regimes. This work demonstrates that control of the charge carrier densities can be efficiently achieved by modifying the injection property with SAM treatment; thus, this approach can achieve polarity conversion of the OFETs.

  14. Forging Futures with Teens and Science Fiction: A Conversation with Greg Bear and David Brin.

    Science.gov (United States)

    Moltz, Sandy

    2003-01-01

    Presents an interview with Greg Bear and David Brin, two science fiction writers who started Reading for the Future, an international project geared toward secondary school students that shows teachers and librarians how science fiction inspires young readers. Discusses programs that have come out of this group; standards for books geared toward…

  15. Objectivism and Education: A Response to David Elkind's "The Problem with Constructivism"

    Science.gov (United States)

    Carson, Jamin

    2005-01-01

    This paper responds to David Elkind's article "The Problem with Constructivism," published in the Summer 2004 issue of The EducationalForum. It argues that Elkind?s thesis?teacher, curricular, and societal readiness lead to the implementation of constructivism?is conceptually problematic. This paper also critiques constructivism and supports…

  16. Romantic Remediation? John Cage and Henry David Thoreau’s Walden State of Mind

    NARCIS (Netherlands)

    Mehring, F.

    2014-01-01

    Rather than identifying Cage as a romantic soul mate of the transcendentalists exhibiting a rebellious attitude against conventions, I will investigate new ways to detect with greater exactness what Sean Wilentz described in the context of David S. Reynolds work on the American Renaissance as “the

  17. David van der Linden, Experiencing Exile: Huguenot Refugees in the Dutch Republic 1680-1700

    Directory of Open Access Journals (Sweden)

    Matthew Glozier

    2016-04-01

    Full Text Available David van der Linden, Experiencing Exile: Huguenot Refugees in the Dutch Republic 1680-1700 (PhD Universiteit Utrecht 2013; Politics and Culture in Europe, 1650-1750; Farnham: Ashgate, 2015, xx + 289 pp., ISBN 978 14 7242 927 8.

  18. Education Policy, Globalization, Commercialization: An Interview with Bob Lingard by David Hursh

    Science.gov (United States)

    Hursh, David

    2017-01-01

    In this interview with David Hursh, Bob Lingard comments on his current and/or recently completed research projects in respect to new modes of global governance in schooling and the complementarity between international large scale assessments and national testing. He also looks at a project that, in conjunction with school leaders, teachers,…

  19. Finding Our Way Back to Healthy Eating: A Conversation with David A. Kessler

    Science.gov (United States)

    Azzam, Amy M.

    2009-01-01

    In this interview, David Kessler, former commissioner of the Food and Drug Administration, explains why so many people overeat. Changing lifestyles promote the constant availability of food and around-the-clock eating. In today's highly processed foods, food companies are able to dial in the exact amount of fat, sugar, and salt that will make…

  20. Exclusion and renewal : identity and Jewishness in Franz Kafka's "The Metamorphosis" and David Vogel's Married Life

    NARCIS (Netherlands)

    Valk, Francina Cornelia

    2015-01-01

    In this study I explore literary structures of identity-formation in the works of assimilated/acculturated Jewish writers: Kafka’s novella “The Metamorphosis” (“Die Verwandlung”, 1912) and David Vogel’s Hebrew novel Married Life. 1929) These authors wrote their works when the failure of Jewish

  1. Congo, de missie en de literatuur: Over David van Reybrouck, J. G. ...

    African Journals Online (AJOL)

    However, the travel books written by Lieve Joris and Bart Castelein and the play Missie (Mission) written by David van Reybrouck (2007) sketched a positive and nostalgic image of the missionary. Keywords: Dutch (post)colonial literature, Congo, missionaries, colonialism. Tydskrif vir Letterkunde Vol. 46 (1) 2009: pp. 123- ...

  2. Käsitsi tegemise võlu / David Jones ; intervjueerinud Kai Lobjakas

    Index Scriptorium Estoniae

    Jones, David, 1953-

    2010-01-01

    10. Kohila keraamikasümpoosionil osalenud briti keraamik ja teoreetik David Jones endast, rakutehnikast, huvist põletamisega seonduvate teemade vastu, Kohila sümpoosioni raames tehtust, keraamika õpetamisest Inglismaal, käsitöö ja keraamika positsioonist praegu ja tulevikus jm.

  3. Enciclopédia e Shoah: fragmento e verbete em Ver: Amor, de David Grossman

    Directory of Open Access Journals (Sweden)

    Matheus Philippe Faria Santos

    2015-05-01

    Full Text Available O romance Ver: Amor, 2007, de David Grossman evidencia uma forma contemporânea de ficção sobre a Shoah, marcada pela fragmentação narrativa e escrita lacunar, que no romance de Grossman evidenciam, paradoxalmente, uma escrita enciclopédica, a partir da configuração do texto como verbete.

  4. Surnuist üles äratamine = Reviving the dead / David Crowley

    Index Scriptorium Estoniae

    Crowley, David, 1966-

    2012-01-01

    Eesti ekspositsioonist "Kui pikk on ühe maja elu?" 13. Venezia arhitektuuribiennaalil "Common Ground" (kuraator David Chipperfield). Tallinna Linnahalli minevikust ja praegusest olukorrast. Kuraator Tüüne-Kristin Vaikla, näituse autorid Urmo Vaikla, Tüüne-Kristin Vaikla, Ingel Vaikla, Maria Pukk, Ivar Lubjak, Veronika Valk. Saksa paviljoni näitusest "Reduce, reuse, recycle"

  5. David Hume's Monetary Theory Revisited: Was He Really a Quantity Theorist and an Inflationist?

    Science.gov (United States)

    Wennerlind, Carl

    2005-01-01

    David Hume's monetary theory has been controversial since its formulation. Lately, the focus has been on Hume's alleged misapplication of the quantity theory of money. While he appears to subscribe to a simple quantity theory with money neutrality, in a famously contested passage in the essay Of Money, he violates the neutrality condition by…

  6. David Cronenberg ja William S. Burroughs kutsuvad teid lantshile / Aare Ermel

    Index Scriptorium Estoniae

    Ermel, Aare, 1957-2013

    1999-01-01

    Mängufilm "Alasti eine" ("Naked Lunch") William S. Burroughs' teose järgi : režissöör ja stsenarist David Cronenberg : Suurbritannia - Kanada 1991. Lähemalt režissööri kohta. Ka Nädal nr. 35, lk. 29

  7. A Response to David Kirk: Personal/Professional Views from US Authors

    Science.gov (United States)

    Hastie, Peter; van der Mars, Hans

    2014-01-01

    This paper represents the views of two scholars in the USA with respect to the scholar lecture presented by David Kirk at the 2012 BERA -- Physical Education and Sport Pedagogy (PESP) Special Interest Group meeting. We discuss how two unique features of the American universities have an impact on both the corporate nature of our work and our…

  8. The Archives of the History of American Psychology: An Interview with David B. Baker.

    Science.gov (United States)

    Prieto, Loreto R.

    2001-01-01

    Presents an interview with David B. Baker, Director of the Archives of the History of American Psychology. Covers topics such as: Baker's interest in the history of psychology, his work at the Archives of the History of American Psychology, and recommendations for teachers when addressing history in non-history courses. (CMK)

  9. David Kirk on Physical Education and Sport Pedagogy: In Dialogue with Steven Stolz (Part 1)

    Science.gov (United States)

    Stolz, Steven A.; Kirk, David

    2015-01-01

    Forming the first of two articles, this dialogue begins from the dilemma posed in the writings of David Kirk that physical education is in crisis because the dominant practice of physical education as "sport-techniques" is resistant to change. In order to make sense of crisis discourse, the discussion explores the potential for change in…

  10. David Hurst Thomas and the Historical Archaeology of the Spanish Borderlands.

    Science.gov (United States)

    Snead, James E.

    2000-01-01

    Discusses David Hurst Thomas' archaeological work on the Spanish borderlands, which integrates field archaeology and documentary history. Focuses on locating and studying the Santa Catalina de Guale. Addresses his project on the Pueblo San Marcos that will further test his ideas about the Spanish mission period. (CMK)

  11. Inconvenient Truths: A Response to the Article by David Stoesz, "The Child Welfare Cartel"

    Science.gov (United States)

    Clark, James J.; Yegidis, Bonnie L.

    2016-01-01

    David Stoesz offers a sweeping critique of the Children's Bureau and social work education by claiming the existence of a "child welfare cartel." He also attacks the quality of social work education and research, which he claims has poorly invested government funding and helped create the unmitigated failures of the American child…

  12. David F. Treagust: congenial soul, science educator, and international research leader

    Science.gov (United States)

    Tobin, Kenneth; Rennie, Leonie; Venville, Grady; Chu, Hye-Eun; Fensham, Peter; Gallagher, James; Duit, Reinders; Graeber, Wolfgang; van den Berg, Ed; Hand, Brian; Ritchie, Stephen; Dillon, Justin

    2011-09-01

    For almost a half century David F. Treagust has been an exemplary science educator who has contributed through his dedication and commitments to students, curriculum development and collaboration with teachers, and cutting edge research in science education that has impacted the field globally, nationally and locally. A hallmark of his outstanding career is his collaborative style that inspires others to produce their best work.

  13. The body in the pool: reflections on David Cronenberg’s 'Maps to the Stars'

    OpenAIRE

    Arnold-de-Simine, Silke

    2016-01-01

    Placing David Cronenberg’s Maps to the Stars (2014) in the Gothic tradition reveals the ghostly and often overlooked mother-daughter dynamics at play in that genre, veering between the internalized fears of Gothic terror and the externalized evil of Gothic horror.

  14. Q & A with Ed Tech Leaders: Interview with David M. Monetti

    Science.gov (United States)

    Fulgham, Susan M.; Shaughnessy, Michael F.

    2014-01-01

    Contributing editors Susan Fulgham and Michael Shaughnessy present their interview with David M. Monetti, Professor in the Department of Psychology and Counseling at Valdosta State University. Monetti teaches courses in educational psychology, learning, and measurement and evaluation. He is actively involved with the public schools as a researcher…

  15. David Hockney’s Early Etchings: Going Transatlantic and Being British

    Directory of Open Access Journals (Sweden)

    Martin Hammer

    2017-05-01

    Full Text Available David Hockney’s early autobiographical prints, My Bonnie Lies Over the Ocean 1961 and the series A Rake’s Progress 1961–3, are examined in relation to contemporary developments in American art and literature, the artist’s affinities with his British modernist contemporaries and predecessors, and other aspects of his emerging sense of artistic and sexual identity.

  16. An Interview with David Rindskopf: A Leading Voice on Teaching Statistics and Methodology

    Science.gov (United States)

    Bembenutty, Hefer

    2011-01-01

    This article presents an interview with David Rindskopf, a Distinguished Professor of Educational Psychology and Psychology at the City University of New York Graduate Center, where he has taught since 1979. His research and teaching are in the area of applied statistics, measurement, and research design. He is a fellow of the American Statistical…

  17. Apollo külastajate lemmikuks on Jan Kausi ja David Mitchelli raamatud / Jaak Urmet

    Index Scriptorium Estoniae

    Urmet, Jaak, 1979-

    2006-01-01

    Apollo kaupluse koduleheküljel valiti parimaks ilukirjandusteoseks Jan Kausi "Tema", tõlgitud ilukirjanduse osas David Mitchelli "Pilveatlas", luuleraamatutest Ott Arderi "Luule sünnib kus sünnib kui sünnib" ja lasteraamatutest Christopher Paolini "Vanem"

  18. Paul Voosen Receives 2013 David Perlman Award for Excellence in Science Journalism—News: Citation

    Science.gov (United States)

    Zaneski, Cyril T.

    2014-01-01

    It's my pleasure to nominate Paul Voosen, the former science reporter for Greenwire, for the David Perlman award. Last November, as Superstorm Sandy pounded the East Coast of the United States, Paul found himself stranded for several days in Miami, mourning a recently deceased family member.

  19. In situ TEM nanoindentation and dislocation-grain boundary interactions : a tribute to David Brandon

    NARCIS (Netherlands)

    de Hosson, J.T.M.; Soer, W.A.; Minor, A.M.; Shan, Z.W.; Stach, E.A.; Asif, S.A.S.; Warren, O.L.

    2006-01-01

    As a tribute to the scientific work of Professor David Brandon, this paper delineates the possibilities of utilizing in situ transmission electron microscopy to unravel dislocation-grain boundary interactions. In particular, we have focused on the deformation characteristics of Al-Mg films. To this

  20. Resident database interfaces to the DAVID system, a heterogeneous distributed database management system

    Science.gov (United States)

    Moroh, Marsha

    1988-01-01

    A methodology for building interfaces of resident database management systems to a heterogeneous distributed database management system under development at NASA, the DAVID system, was developed. The feasibility of that methodology was demonstrated by construction of the software necessary to perform the interface task. The interface terminology developed in the course of this research is presented. The work performed and the results are summarized.

  1. Imitate Me; Don't Imitate Me: Mimeticism in David Bartholomae's "Inventing the University."

    Science.gov (United States)

    Boyd, Richard

    1991-01-01

    Discusses the issue of the instructor's role in the classroom with respect to David Bartholomae's "Inventing the University." Suggests an approach informed by the literary and anthropological theories of Rene Girard. Deals with Girard's views on mimetic desire. Asserts the double-bind of this view--"imitate me; don't imitate…

  2. The image of the blessed monarch, the Holy King of Georgia David the Builder

    Directory of Open Access Journals (Sweden)

    Efimov Vladimir Fedorovich

    2014-07-01

    Full Text Available The article considers the biography of the saint Georgian monarch, David the Builder, analyzes his actions, church, external and internal policy. Finally it draws a conclusion that all his life was dedicated to the service of God and neighbor. Thus, his life was a model of Christian Ministry, he occupied a responsible position in society.

  3. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  4. Copper-mediated controlled/"living" radical polymerization in polar solvents: insights into some relevant mechanistic aspects.

    Science.gov (United States)

    Guliashvili, Tamaz; Mendonça, Patrícia V; Serra, Arménio C; Popov, Anatoliy V; Coelho, Jorge F J

    2012-04-10

    The field of transition-metal-mediated controlled/"living" radical polymerization (CLRP) has become the subject of intense discussion regarding the mechanism of this widely-used and versatile process. Most mechanistic analyses (atom transfer radical polymerization (ATRP) vs. single-electron transfer living radical polymerization (SET-LRP)) have been based on model experiments, which cannot correctly mimic the true reaction conditions. We present, for the first time, a determination of the [Cu(I)Br]/[L] (L=nitrogen-based chelating ligand) ratio and the extent of Cu(I)Br/L disproportionation during CLRP of methyl acrylate (MA) in dimethylsulfoxide (DMSO) with Cu(0) wire as a transition-metal catalyst source. The results suggest that Cu(0) acts as a supplemental activator and reducing agent of Cu(II)Br(2)/L to Cu(I)Br/L. More importantly, the Cu(I)Br/L species seem to be responsible for the activation of SET-LRP. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A Bmp/Admp regulatory circuit controls maintenance and regeneration of dorsal-ventral polarity in planarians.

    Science.gov (United States)

    Gaviño, Michael A; Reddien, Peter W

    2011-02-22

    Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway, BMP signaling, controls development of the dorsoventral (DV) axis throughout the Bilateria. In vertebrates, spatially opposed expression of the BMP family proteins Bmp4 and Admp (antidorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans). By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a regulatory circuit of oppositely expressed bmp4 and admp genes represents a deuterostome-specific innovation. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed ventrally and laterally in adult Schmidtea mediterranea planarians, opposing the dorsal-pole expression of Smed-bmp4. Smed-admp is required for regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. A Bmp/Admp regulatory circuit controls maintenance and regeneration of dorsal-ventral polarity in planarians

    Science.gov (United States)

    Gaviño, Michael A.; Reddien, Peter W.

    2011-01-01

    Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway – BMP signaling – controls development of the dorsoventral (DV) axis throughout the Bilateria [1-8]. In vertebrates, spatially opposed expression of the BMP-family signaling proteins Bmp4 and Admp (anti-dorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal [9-11]. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans) [12]. By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a DV regulatory circuit of oppositely expressed bmp4 and admp genes represents an innovation specific to deuterostomes. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed at the ventral pole and laterally in adult Schmidtea mediterranea planarians, spatially opposing the dorsal-pole domain of Smed-bmp4 expression. Smed-admp is required for planarian regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis. PMID:21295483

  7. The post-perspectival: screens and time in David Lynch's Inland Empire

    Directory of Open Access Journals (Sweden)

    Anne Jerslev

    2012-03-01

    Full Text Available Taking Anne Friedberg's notion of the post-perspectival as the point of departure for her analysis of David Lynch's digitally shot and edited Inland Empire from 2006, Anne Jerslev argues that the film deconstructs continuous time and coherent space by constructing multiple planes of representation, multiple layerings of screens and, hence, multiple and fractured modes of perception. The article further suggests that the film's enigmatic structure might best be understood with reference to a new media genre like the website with its hyperlink structure. Finally, the article discusses how a sense of ubiquitous surveillance coalesces with the screen logic.Author Biography Anne Jerslev (PhD is Professor of Film and Media Studies at the Department of Media, Cognition and Communication, University of Copenhagen. Anne Jerslev has published and edited books in Danish and English and published dozens of articles in journals and anthologies in Danish, Scandinavian languages, German and English. Her first book was titled David Lynch i vore øjne (David Lynch in our eyes (1991; it was published in German in 1995 under the title David Lynch—mentale Landschaften. After the Lynch book she published books about cult movies, youth and media and media and intimacy. She has edited two volumes in English, Realism and Reality in Film and Media (2002, where she contributed a piece about Lars von Trier's The Idiots, and Performative Realism (co-edited with Rune Gade (2005. Her latest edited volume (co-edited with Christa Lykke Christensen is Hvor går grænsen? Brudflader i den moderne mediekultur [Are there no limits? The crossing of boundaries in contemporary media culture] (Copenhagen 2010. She is currently editing a volume about “Impure Cinema” together with professor Lúcia Nagib from the University of Leeds, which will appear in 2013. Her own contribution to the book is an article about David Lynch's Interview Project.

  8. Dynamics and Control of a Biomimetic Vehicle Using Biased Wingbeat Forcing Functions: Part 2 - Controller (Postprint)

    Science.gov (United States)

    2010-01-01

    NUMBER 5c. PROGRAM ELEMENT NUMBER 62201F 6. AUTHOR(S) David B. Doman, Michael W. Oppenheimer, and David O. Sigthorsson (AFRL/ RBCA ) 5d...REPORT NUMBER Control Design and Analysis Branch (AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air Vehicles

  9. An Interview with David Dabydeen on Literature and Politics

    Directory of Open Access Journals (Sweden)

    Ruzbeh Babaee

    2016-07-01

    s rainforest, you will experience the sublime which contain elemental terror and a tragic sense of how life is constantly being destroyed and remade and destroyed by tooth and claw. [1] Ruzbeh Babaee [2] David Dabydeen

  10. Ultra-thin, single-layer polarization rotator

    Energy Technology Data Exchange (ETDEWEB)

    Son, T. V.; Truong, V. V., E-mail: Truong.Vo-Van@Concordia.Ca [Department of Physics, Concordia University, Montreal, Quebec, H4B 1R6 (Canada); Do, P. A.; Haché, A. [Département de Physique et d’Astronomie, Université de Moncton, Moncton, New Brunswick, E1A 3E9 (Canada)

    2016-08-15

    We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal. Changes in refractive indices create unequal phase shifts on s- and p-polarization components of incident light, and rotation of linear polarization shows intensity modulation by a factor of 10{sup 3} when transmitted through polarizers. This makes possible polarization rotation devices as thin as 50 nm that would be activated thermally, optically or electrically.

  11. Polarization in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    1995-12-31

    Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.

  12. EAT-2, a SAP-like adaptor, controls NK cell activation through phospholipase Cγ, Ca++, and Erk, leading to granule polarization.

    Science.gov (United States)

    Pérez-Quintero, Luis-Alberto; Roncagalli, Romain; Guo, Huaijian; Latour, Sylvain; Davidson, Dominique; Veillette, André

    2014-04-07

    Ewing's sarcoma-associated transcript 2 (EAT-2) is an Src homology 2 domain-containing intracellular adaptor related to signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), the X-linked lymphoproliferative gene product. Both EAT-2 and SAP are expressed in natural killer (NK) cells, and their combined expression is essential for NK cells to kill abnormal hematopoietic cells. SAP mediates this function by coupling SLAM family receptors to the protein tyrosine kinase Fyn and the exchange factor Vav, thereby promoting conjugate formation between NK cells and target cells. We used a variety of genetic, biochemical, and imaging approaches to define the molecular and cellular mechanisms by which EAT-2 controls NK cell activation. We found that EAT-2 mediates its effects in NK cells by linking SLAM family receptors to phospholipase Cγ, calcium fluxes, and Erk kinase. These signals are triggered by one or two tyrosines located in the carboxyl-terminal tail of EAT-2 but not found in SAP. Unlike SAP, EAT-2 does not enhance conjugate formation. Rather, it accelerates polarization and exocytosis of cytotoxic granules toward hematopoietic target cells. Hence, EAT-2 promotes NK cell activation by molecular and cellular mechanisms distinct from those of SAP. These findings explain the cooperative and essential function of these two adaptors in NK cell activation.

  13. Primordial Inflation Polarization Explorer: Status and Plans

    Science.gov (United States)

    Kogut, Alan

    2009-01-01

    The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

  14. RHIC polarized proton performance in run-8.

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D.; et al.

    2008-06-23

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.

  15. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live......In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...

  16. Precision Targeting: Reduced Pesticide Use Strategy for Pharaoh’s Ant (Hymenoptera: Formicidae) Control

    Science.gov (United States)

    1999-07-19

    AND SUBTITLE Precision Targeting: Reduced Pesticide Use Strategy for Pharaoh’s Ant (Hymenoptera: Formicidae ) Control 6. AUTHOR(S) David F. Williams...TARGETING: REDUCED PESTICIDE USE STRATEGY FOR PHARAOH’S ANT (HYMENOPTERA: FORMICIDAE ) CONTROL DAVID F. WILLIAMS, RICHARD J. BRENNER AND DAVID MILNE...space may benefit from this method of control. This Precision targeting - reduced pesticide use strategy for Pharaoh’s ant (Hymenoptera: Formicidae

  17. David Bowie’s Influence on JoJo’s Bizarre Adventure

    Directory of Open Access Journals (Sweden)

    Francesco-Alessio Ursini

    2017-03-01

    Full Text Available This article analyses the influence of David Bowie’s work in JoJo’s Bizarre Adventure, a manga known for its wealth of references to western popular culture. It is argued that David Bowie’s cultural reception can be attested via the presence of three narrative themes featuring in this manga series. The first theme is the exploration of diverse genres and an innovative, genre-defying attitude. The second theme is the use of avant-garde, flamboyant and gender-ambiguous aesthetics for its fictional characters. The third theme is a self-reflexive approach to the creation of fictional characters, intended as an awareness of the temporary, transient nature of their role as reluctant heroes in their own stories.

  18. Dialectical materialism and the construction of a new quantum theory: David Joseph Bohm, 1917-1992

    Energy Technology Data Exchange (ETDEWEB)

    Forstner, C.

    2005-07-01

    This paper touches on some general questions of theory construction in physics, by presenting a biographical case study of David Bohm through the perspective of Fleckian thought-collectives and their thought-style. In the 1920s a small elite of physicists established the Copenhagen Interpretation of quantum mechanics as a new thought-style in the thought-collective of the physicists. In the following decade the Copenhagen Interpretation was transferred from Europe to the USA, from one thought-collective into another, and was integrated into a specific American thought-style. David Bohm was initiated in this mode of thought during his undergraduate studies at the Pennsylvania State College and his graduate studies at Caltech and the University of California at Berkeley. (orig.)

  19. A CRITIC APPROACH OF HENRY JAMES SEEN BY NORTHROP FRYE AND DAVID LODGE

    Directory of Open Access Journals (Sweden)

    Paula-Andreea ONOFREI

    2011-05-01

    Full Text Available The present paper represents our attempt to decipher the literary ideas that Henry James, Northrop Frye and David Lodge brought in criticism, therefore our main focus is on The Art of Fiction and The Art of the Novel, both belonging to Henry James, The Anatomy of Criticism -by Northrop Frye and The Art of Fiction of David Lodge. Particular attention is going to be given to Henry James and the concepts that he introduced in narratology, we will refer to the distinct features of Modernism, the literary current which has H. James as its representative and to the way Frye and Lodge regard „The Master’s” work from a critic point of view. The purpose is to familiarize the readers with the American author Henry James and to understand the complexity of his work.

  20. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  1. Rapport de frais de 2010-2011 pour David Malone | CRDI - Centre ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Rapport de frais de 2010-2011 pour David Malone. Frais de déplacement et dépenses d'accueil de l'exercice 2010 - 2011. Nous finançons des chercheurs qui inspirent des changements mondiaux. Abonnez-vous · Carrières · Communiquez avec nous · Désabonnez-vous · Plan du site. Suivez-nous; Facebook · Twitter ...

  2. Rapport de frais de 2011-2012 pour David Malone | CRDI - Centre ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Rapport de frais de 2011-2012 pour David Malone. Frais de déplacement et dépenses d'accueil de l'exercice 2011 - 2012. Nous finançons des chercheurs qui inspirent des changements mondiaux. Abonnez-vous · Carrières · Communiquez avec nous · Désabonnez-vous · Plan du site. Suivez-nous; Facebook · Twitter ...

  3. Rapport de frais de 2009-2010 pour David Malone | CRDI - Centre ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Rapport de frais de 2009-2010 pour David Malone. Frais de déplacement et dépenses d'accueil de l'exercice 2009 - 2010 · Ce que nous faisons · Financement · Ressources · À propos du CRDI. Savoir. Innovation. Solutions. Carrières · Communiquez avec nous · Plan du site. Abonnez-vous à notre bulletin électronique dès ...

  4. Dr. David Brown poses with a portrait of Ronald McNair

    Science.gov (United States)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Dr. David Brown, a NASA astronaut, poses with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  5. Review: Henry E. Brady & David Collier (Hrsg.) (2004). Rethinking Social Inquiry: Diverse Tools, Shared Standards

    OpenAIRE

    Catón, Matthias

    2006-01-01

    Das Buch Rethinking Social Inquiry, herausgegeben von Henry E. BRADY und David COLLIER, ist eine Antwort auf den Band von KING, KEOHANE und VERBA (1994), in dem versucht wird, Standards der quantitativen Forschung in der qualitativen Forschung einzuführen. Die Autoren des hier rezensierten Buchs kritisieren viele der Vorschläge, da sie argumentieren, dass qualitative Forschung anderer Werkzeuge bedürfe. Trotzdem stimmen sie zu, dass die Grundlagen des Forschungsaufbaus ähnlich sind. Das Buch ...

  6. Review: Henry E. Brady & David Collier (Eds.) (2004). Rethinking Social Inquiry: Diverse Tools, Shared Standards

    OpenAIRE

    Matthias Catón

    2006-01-01

    Das Buch Rethinking Social Inquiry, herausgegeben von Henry E. BRADY und David COLLIER, ist eine Antwort auf den Band von KING, KEOHANE und VERBA (1994), in dem versucht wird, Standards der quantitativen Forschung in der qualitativen Forschung einzuführen. Die Autoren des hier rezensierten Buchs kritisieren viele der Vorschläge, da sie argumentieren, dass qualitative Forschung anderer Werkzeuge bedürfe. Trotzdem stimmen sie zu, dass die Grundlagen des Forschungsaufbaus ähnlich sind. Das Buch ...

  7. Hacking the aesthetic: David Haines and Joyce Hinterding’s new ecologies of signal

    OpenAIRE

    Murphie, Andrew

    2012-01-01

    Award winning Australian electronic artists David Haines and Joyce Hinterding’s installation work is discussed as ‘‘signal-work.’’ Their work reconfigures signal within original assemblages involving subtle audio, high resolution video (both recorded and animated), kilometers of coiled copper wire, antennae or home-built electronics, electrostatic disturbances, the like of very low frequency radiation from the Milky Way, and cross-signal processing. The article develops a context for thinking...

  8. David Bohm, sua estada no Brasil e a teoria quântica

    Directory of Open Access Journals (Sweden)

    Olival Freire Jr.

    1994-04-01

    Full Text Available Quando o artigo Uma proposta de interpretação da teoria quântica em termos de variáveis" escondidas", de autoria de David Bohm, foi publicado, ele estava no Brasil, na Universidade de São Paulo. Atingido pelo McCarthysm, Bohm perdeu sua posição na Universidade de Princeton e, por isto, veio para o Brasil, onde permaneceu de outubro de 1951 a janeiro de 1955. Analisamos sua atividade neste período, incluindo sua interpretação da teoria quântica, e a recepção desta pela comunidade científica. Destacamos que, apesar das condições adversas, a sociedade brasileira foi capaz de acolher o cidadão e cientista perseguido politicamente, e assegurar a continuidade de seu trabalho científico. A ciência brasileira foi bastante beneficiada pelo ensino, pela pesquisa e pela permanente preocupação com os fundamentos da física, características do trabalho de David Bohm.When the paper A Suggested interpretation of the quantum theory in terms of "hidden" variables, by David Bohm, was published he has been in Brazil at University of São Paulo. He was hit by the McCarthysm, lost his post at the Princeton University and by this he came to the Brazil, where he stayed from 1951 (October to 1955 (January. We analysed his activity in this period, including his interpretation of the quantum theory and its reception in the scientific community. We pointed out that notwithstanding the adverse conditions, the Brazilian society was able to recept the political persecuted scientist and citizen and to warrant the continuity of his scientific work. The Brazilian science was very benefited by the teaching, the research and the permanent preoccupation with the foundations of physics, features of David Bohm's work.

  9. Building thermal loads: A case study for David Hellen Petta public secondary school

    CSIR Research Space (South Africa)

    Kumirai, T

    2013-03-01

    Full Text Available Building Handbook South Africa Volume 5: The Essential Guide Building Thermal Loads: A case study for David Hellen Petta public secondary school T Kumirai Built Environment, Council for Scientific and Industrial Research PO Box 395, Pretoria..., 0001 South Africa tkumirai@csir.co.za Abstract Statistics published by the Department of Basic Education in November 2010 reveal the following: a) There are 11 834 516 learners that attend public schools, b) there are 387 837 educators...

  10. David Mills, Microbiology of food production built environments: dairies and wineries

    OpenAIRE

    Schriml, Lynn

    2017-01-01

    David Mills, University of California Davis Microbiology of food production built environments: dairies and wineriesOn October 10-12th, 2017 the Alfred P. Sloan Foundation and The National Academies of Sciences, Engineering and Medicine co-hosting MoBE 2017 (Microbiology of the Built Environment Research and Applications Symposium) at the National Academy of Sciences Building to present the current state-of-the-science in understanding the formation and function of microbial communities in bu...

  11. J. David Creswell: Award for Distinguished Scientific Early Career Contributions to Psychology.

    Science.gov (United States)

    2014-11-01

    APA's Awards for Distinguished Scientific Early Career Contributions to Psychology recognize excellent young psychologists who have not held a doctoral degree for more than nine years. One of the 2014 award winners is J. David Creswell, for "outstanding and innovative research on mechanisms linking stress management strategies to disease." Creswell's award citation, biography, and a selected bibliography are presented here. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  12. Which research methods for special education? Information from David Mitchell’s work

    Directory of Open Access Journals (Sweden)

    Marta Pellegrini

    2017-01-01

    Full Text Available In this paper we asked what are the research methods used to ensure the reliability of knowledge in special education and if these may be based on the same criteria used by the research with all classroom. To answer these questions at first was carried out an analysis of the research methods of the work conducted by David Mitchell (2008; 2014, that is now the most complete and reliable overview of effective strategies in special education. Than only the experimental method researches and meta-analysis ware considered to evaluate in which contexts had been carried out and whit which disabilities.Quali metodi di ricerca per la didattica speciale? Alcune indicazioni dal lavoro di David MitchellNel presente contributo ci si chiede quali siano i metodi di ricerca che garantiscono maggiore affidabilità delle conoscenze nell’ambito della didattica speciale e se questi possano basarsi sugli stessi criteri impiegati nelle ricerche a livello dell’intera classe. Per rispondere a queste domande in un primo momento è stata compiuta un’analisi delle metodologie di ricerca a cui fa riferimento il lavoro condotto da David Mitchell (2008; 2014 considerato la sintesi più completa e affidabile delle strategie efficaci per la didattica speciale. In un secondo momento sono state considerate solo gli studi sperimentali e le meta-analisi per valutare in quali contesti sono stati svolti e su quali disabilità.

  13. Using optically scanned 3D data in the restoration of Michelangelo's David

    Science.gov (United States)

    Scopigno, Roberto; Cignoni, Paolo; Callieri, Marco; Ganovelli, Fabio; Impoco, G.; Pingi, P.; Ponchio, F.

    2003-10-01

    Modern 3D scanning technologies allow to reconstruct 3D digital representations of Cultural Heritage artifacts in a semi-automatic way, characterized by very high accuracy and wealth of details. The availability of an accurate digital representation opens several possibilities of utilization to experts (restorers, archivists, museum curators), or to ordinary people (students, museum visitors). 3D scanned data are commonly used for the production of animations, interactive visualizations, or virtual reality applications. A much more exciting opportunity is to use these data in the restoration of Cultural Heritage artworks. The integration between 3D graphic and restoration represents an open research field where many new supporting tools are required; the David restoration project has given several starting points and guidelines to the definition and development of innovative solutions. Digital 3D models can be used in two different but not subsidiary modes: as an instrument for the execution of specific investigations and as a supporting media for the archival and integration of all the restoration-related information, gathered with the different studies and analysis performed on the artwork. In this paper we present some recent work done in the framework of the Michelangelo's David restoration project. A 3D model of the David was reconstructed by the Digital Michelangelo Project, using laser-based 3D scanning technology. We have developed some tools to make those data accessible and useful in the restoration. Preliminary results are reported here together with some directions for further research.

  14. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  15. Reversible Polarization Rotation in Epitaxial Ferroelectric Bilayers

    DEFF Research Database (Denmark)

    Liu, Guangqing; Zhang, Qi; Huang, Hsin-Hui

    2016-01-01

    large-scale polarization rotation switching (≈60 μC cm−2) and an effective d 33 response 500% (≈250 pm V−1) larger than the PZT-R layer alone. Furthermore, this enhancement is stable for more than 107 electrical switching cycles. These bilayers present a simple and highly controllable means to design...... and optimize rotational polar systems as an alternate to traditional composition-based approaches. The precise control of the subtle interface-driven interactions between the lattice and the external factors that control polarization opens a new door to enhanced—or completely new—functional properties....

  16. Polar metals by geometric design

    Science.gov (United States)

    Kim, T. H.; Puggioni, D.; Yuan, Y.; Xie, L.; Zhou, H.; Campbell, N.; Ryan, P. J.; Choi, Y.; Kim, J.-W.; Patzner, J. R.; Ryu, S.; Podkaminer, J. P.; Irwin, J.; Ma, Y.; Fennie, C. J.; Rzchowski, M. S.; Pan, X. Q.; Gopalan, V.; Rondinelli, J. M.; Eom, C. B.

    2016-05-01

    Gauss’s law dictates that the net electric field inside a conductor in electrostatic equilibrium is zero by effective charge screening; free carriers within a metal eliminate internal dipoles that may arise owing to asymmetric charge distributions. Quantum physics supports this view, demonstrating that delocalized electrons make a static macroscopic polarization, an ill-defined quantity in metals—it is exceedingly unusual to find a polar metal that exhibits long-range ordered dipoles owing to cooperative atomic displacements aligned from dipolar interactions as in insulating phases. Here we describe the quantum mechanical design and experimental realization of room-temperature polar metals in thin-film ANiO3 perovskite nickelates using a strategy based on atomic-scale control of inversion-preserving (centric) displacements. We predict with ab initio calculations that cooperative polar A cation displacements are geometrically stabilized with a non-equilibrium amplitude and tilt pattern of the corner-connected NiO6 octahedra—the structural signatures of perovskites—owing to geometric constraints imposed by the underlying substrate. Heteroepitaxial thin-films grown on LaAlO3 (111) substrates fulfil the design principles. We achieve both a conducting polar monoclinic oxide that is inaccessible in compositionally identical films grown on (001) substrates, and observe a hidden, previously unreported, non-equilibrium structure in thin-film geometries. We expect that the geometric stabilization approach will provide novel avenues for realizing new multifunctional materials with unusual coexisting properties.

  17. David Huffman

    Indian Academy of Sciences (India)

    Huffman had his schooling and undergraduate college education in Ohio where he earned a bachelor's degree in Electrical Engineering at the age of 18. He then worked in the US Navy as a radar maintenance officer on a destroyer that was supposed to clear mines from Japanese and Chinese waters after World War II.

  18. Dynamics and Control of a Minimally Actuated Biomimetic Vehicle: Part 2 - Control (Postprint)

    Science.gov (United States)

    2009-08-01

    AUTHOR(S) David B. Doman, Michael W. Oppenheimer, and David O. Sigthorsson (AFRL/ RBCA ) 5d. PROJECT NUMBER 2401 5e. TASK NUMBER N/A 5f. WORK...Branch (AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air Vehicles Directorate Wright-Patterson Air Force Base, OH 45433

  19. LA OBSOLESCENCIA COMO OPORTUNIDAD PARA UNA INFRAESTRUCTURA SOCIAL: TORRE DAVID/ Obsolescence as an opportunity for social infrastructure: the Tower of David

    Directory of Open Access Journals (Sweden)

    Diego Martínez Navarro

    2015-11-01

    Full Text Available RESUMEN La ocupación del Centro Financiero Cofinanzas, más conocido como Torre David, ha sido tan alabada como criticada. Quizá porque más allá de la ilegalidad, la apropiación del símbolo de una época de desigualdad puso en jaque ciertos pilares fundamentales en la producción de lo urbano. De un lado las políticas económicas y sociales, que salvo excepciones no han hecho sino impulsar la desigualdad, la pobreza y la exclusión social. Del otro la academia, la profesión y las políticas urbanas heredadas del planeamiento urbano moderno, las cuales han probado fomentar la segregación espacial, anular la diversidad y destruir el ámbito público. Pero este complejo de 45 plantas y 110.000 m2 era una entidad híbrida, vertical y vacante en el mismo corazón de la ciudad cuya obsolescencia como objeto físico, político y económico fue objetivo de una presión social ya incontenible. Tanto por su escala y diversidad como por su estado inacabado, sus moradores descubrieron una condición urbana excepcional para reconstruir su nueva identidad como ciudadanos. Un conjunto de cinco sistemas abiertos con los que transformar aquella obsolescencia en una parte de la ciudad alternativa; una infraestructura social. Como ya hicieran otros maestros en el pasado el proceso de Torre David replantea, ahora de forma anónima, bajo qué condiciones los sistemas abiertos permiten elaborar estrategias de regeneración urbana y social, sistemas con los que diluir las complicadas fronteras internas creadas en la ciudad contemporánea. SUMMARY The occupation of the Cofinanzas Financial centre, better known as the Tower of David, has been praised as well as criticised. Perhaps because beyond the illegality, the appropriation of a symbol of a time of inequality threatened certain fundamental pillars on the production of urban. On one hand, the economic and social policies, that with some exceptions only fuelled the inequality, poverty, and social exclusion

  20. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  1. DAVID Knowledgebase: a gene-centered database integrating heterogeneous gene annotation resources to facilitate high-throughput gene functional analysis

    Directory of Open Access Journals (Sweden)

    Baseler Michael W

    2007-11-01

    Full Text Available Abstract Background Due to the complex and distributed nature of biological research, our current biological knowledge is spread over many redundant annotation databases maintained by many independent groups. Analysts usually need to visit many of these bioinformatics databases in order to integrate comprehensive annotation information for their genes, which becomes one of the bottlenecks, particularly for the analytic task associated with a large gene list. Thus, a highly centralized and ready-to-use gene-annotation knowledgebase is in demand for high throughput gene functional analysis. Description The DAVID Knowledgebase is built around the DAVID Gene Concept, a single-linkage method to agglomerate tens of millions of gene/protein identifiers from a variety of public genomic resources into DAVID gene clusters. The grouping of such identifiers improves the cross-reference capability, particularly across NCBI and UniProt systems, enabling more than 40 publicly available functional annotation sources to be comprehensively integrated and centralized by the DAVID gene clusters. The simple, pair-wise, text format files which make up the DAVID Knowledgebase are freely downloadable for various data analysis uses. In addition, a well organized web interface allows users to query different types of heterogeneous annotations in a high-throughput manner. Conclusion The DAVID Knowledgebase is designed to facilitate high throughput gene functional analysis. For a given gene list, it not only provides the quick accessibility to a wide range of heterogeneous annotation data in a centralized location, but also enriches the level of biological information for an individual gene. Moreover, the entire DAVID Knowledgebase is freely downloadable or searchable at http://david.abcc.ncifcrf.gov/knowledgebase/.

  2. Polarization methods for diode laser excitation of solid state lasers

    Science.gov (United States)

    Holtom, Gary R.

    2008-11-25

    A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

  3. High-Tc superconducting thin films with composition control on a sub-unit cell level; the effect of the polar nature of the cuprates

    NARCIS (Netherlands)

    Koster, Gertjan; Brinkman, Alexander; Hilgenkamp, Johannes W.M.; Rijnders, Augustinus J.H.M.; Blank, David H.A.

    2008-01-01

    Inspired by the work of Ohtomo and Hwang in 2004, we shed new light on thin films of layered cuprate high-Tc superconductors (HTS). In principle all HTS materials consist of charged perovskite-like layers which in thin films can lead to polar discontinuities at the interfaces of different materials.

  4. Amplification of spin-current polarization

    Science.gov (United States)

    Saha, D.; Holub, M.; Bhattacharya, P.

    2007-08-01

    A ferromagnet/semiconductor based electrically controlled spin-current amplifier using a dual-drain nonlocal lateral spin valve is demonstrated. The spin polarization injected by the source into the channel is amplified at the second drain contact. An amplified current spin polarization of 100% is measured. The controlled variation of amplifier gain with bias is also demonstrated. The observations are explained in the framework of the spin drift-diffusion model.

  5. Light-matter interactions in a polarization standing wave

    OpenAIRE

    Fang, X.; MacDonald, K.F.; Zheludev, N.I.

    2015-01-01

    We report on the application of polarization standing waves (PSW) to the coherent control of light-matter interactions in planar photonic nanostructures. Such waves, formed by counter-propagating (linear or circular) orthogonally polarized beams can uniquely detect polarization conversion, planar chirality and related asymmetric transmission effects.

  6. [Review] Polarization and Polarimetry

    Science.gov (United States)

    Trippe, Sascha

    2014-02-01

    Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and X/γ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.

  7. Getting Past the ‘Post-’: History and Time in the Fiction of David Mitchell

    Directory of Open Access Journals (Sweden)

    Maria Beville

    2015-12-01

    Full Text Available This paper examines David Mitchell’s Cloud Atlas (2004 and The Thousand Autumns of Jacob de Zoet (2010, with a particular focus on history and narrative time. It seeks to offer an alternative perspective on the multiple and intertwined fictional narratives of Mitchell’s oeuvre as these evidence a move past the "post-" of postmodernism. Keywords: David Mitchell, time, narrative, historiography, experimental fiction, post-postmodernismPostmodernism has cast an extended influence over much literary criticism in the last fifty years. However, with the end of the noughties now in reach of critical hindsight, and with the shock of September 11, 2001 beginning to subside, significant attention is turning once again toward the new literary vanguard. Efforts to discuss post-postmodernism, critical realism, new materialism, and new-millennial writing are certainly on a par with artistic and literary efforts to move beyond postmodernist playfulness and relativism. Within this broader framework, scholars have debated the fiction of David Mitchell, often straining to include his literary experimentalism with categories of the postmodern. However, resisting these efforts in the two novels chosen for analysis here, Mitchell’s writing appears to return from the abstraction and playfulness of postmodern poetics to settle as an engaged writing practice concerned with the materiality of time and of history. With time and history as its conceptual anchors, Mitchell’s more literary practice in the novels discussed here confronts developed postmodernist approaches to the past through an insistence upon a sense of time that abjures postmodern paradigms of uncertainty and relativity. This paper will examine time and narrative in relation to selected recent works by Mitchell in order to allow an alternative perspective on the workings of the multiple and intertwined fictional narratives across his novels; a perspective which can enlarge our understanding of how

  8. Long-term results after aortic valve-sparing operation (David I).

    Science.gov (United States)

    Shrestha, Malakh; Baraki, Hassina; Maeding, Ilona; Fitzner, Sebastian; Sarikouch, Samir; Khaladj, Nawid; Hagl, Christian; Haverich, Axel

    2012-01-01

    Aortic valve-sparing David procedure has gained broad acceptance. However, few long-term results have been published. We present our results. More than 450 David procedures have been performed in our institution so far. Of these, 126 patients were operated between July 1993 and December 2000. Median age was 57 (8-83) years and 46 (36.5%) were female. As many as 26 (20.6%) had Marfan syndrome, 21 (16.7%) had acute aortic dissection type A (AADA) and 67 (53.2%) had additional procedures. There were six (4.8%) deaths in 30 post-operative period (POD), four of whom had AADA. In the follow-up, there were 32 (25.4%) late deaths, 11 (34.4%) of these were caused by cardiac or underlying disease or op-related. As many as 15 (11.9%) patients were re-operated; six (40%) were Marfan patients and two (13.3%) had early endocarditis. Follow-up echocardiography of 76 (60.3%) event-free patients showed valve insufficiency (AI)≤AI I° in 68 (89.5%) and grade II in 7 (9.2%) patients. Leaflet degeneration due to proposed leaflet contact with the straight Dacron graft was not observed. A total of 36 (47.4%) patients were in New York Heart Association (NYHA) class I, 33 (43.4%) in NYHA II, and five (6.6%) were in class III. During the entire follow-up of 790 patient-years, there was no stroke or major bleeding. Survival at 1, 5 and 10 years was 93%, 85% and 70%, respectively. Freedom from valve replacement at 1, 5 and 10 years was 96%, 91% and 87%, respectively. Regardless of the underlying pathology, valve-sparing David I procedure has acceptable long-term results. Valve-related complications such as stroke or major bleeding is exceedingly low.

  9. Long-term results after aortic valve-sparing operation (David I)†

    Science.gov (United States)

    Shrestha, Malakh; Baraki, Hassina; Maeding, Ilona; Fitzner, Sebastian; Sarikouch, Samir; Khaladj, Nawid; Hagl, Christian; Haverich, Axel

    2012-01-01

    OBJECTIVE Aortic valve-sparing David procedure has gained broad acceptance. However, few long-term results have been published. We present our results. METHODS More than 450 David procedures have been performed in our institution so far. Of these, 126 patients were operated between July 1993 and December 2000. Median age was 57 (8–83) years and 46 (36.5%) were female. As many as 26 (20.6%) had Marfan syndrome, 21 (16.7%) had acute aortic dissection type A (AADA) and 67 (53.2%) had additional procedures. RESULTS There were six (4.8%) deaths in 30 post-operative period (POD), four of whom had AADA. In the follow-up, there were 32 (25.4%) late deaths, 11 (34.4%) of these were caused by cardiac or underlying disease or op-related. As many as 15 (11.9%) patients were re-operated; six (40%) were Marfan patients and two (13.3%) had early endocarditis. Follow-up echocardiography of 76 (60.3%) event-free patients showed valve insufficiency (AI) ≤ AI I° in 68 (89.5%) and grade II in 7 (9.2%) patients. Leaflet degeneration due to proposed leaflet contact with the straight Dacron graft was not observed. A total of 36 (47.4%) patients were in New York Heart Association (NYHA) class I, 33 (43.4%) in NYHA II, and five (6.6%) were in class III. During the entire follow-up of 790 patient-years, there was no stroke or major bleeding. Survival at 1, 5 and 10 years was 93%, 85% and 70%, respectively. Freedom from valve replacement at 1, 5 and 10 years was 96%, 91% and 87%, respectively. CONCLUSIONS: Regardless of the underlying pathology, valve-sparing David I procedure has acceptable long-term results. Valve-related complications such as stroke or major bleeding is exceedingly low. PMID:21632258

  10. Electron Cyclotron Waves Polarization in the TJII Stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Cappa, A.; Martinez-Fernandez, J.; Wagner, D.

    2013-05-01

    This report describes the theoretical calculations related with the electron cyclotron (EC) waves polarization control in the TJII stellarator. Two main aspects will be distinguished: the determination of the vacuum polarization that the wave must exhibit if a given propagation mode in a cold plasma is desired and the calculation of the behavior of the grooved polarizers and other transmission systems used to launch the vacuum wave with the required polarization. (Author) 13 refs.

  11. Switching the response of metasurfaces in polarization standing waves

    OpenAIRE

    Fang, X.; MacDonald, K.F.; Zheludev, N.I.

    2015-01-01

    We demonstrate experimentally that standing waves of polarization, as opposed to intensity, can be engaged to coherently control light-matter interactions in planar photonic nanostructures, presenting unique opportunities for all-optical data processing and polarization-dependent molecular spectroscopy. Such waves, formed by counter-propagating (linear or circular) orthogonally polarized beams can, for example, uniquely detect polarization conversion, planar chirality and related asymmetric t...

  12. Polarization in Sagittarius A*

    OpenAIRE

    Bower, Geoffrey C.

    2000-01-01

    We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion disks, jets and their environments. Linear polarization observations have shown that Sgr A* is unpolarized at frequencies as high as 86 GHz. However, recent single-dish observations indicate that Sgr A* may have strong linear polarization at frequencies higher...

  13. Kamikaze Baby: David F. Benson o la nueva poesía de los Estados Unidos

    Directory of Open Access Journals (Sweden)

    Enrique Santos Molano

    1982-07-01

    Full Text Available Cuando leí por primera vez los poemas de "Kamilcaze Baby", supuse su autor a un veterano de la Segunda Guerra Mnudial, por la profunda madurez y la subyugante filosofía que los inspira. Una segunda lectura, más analítica, me hizo ver que el poeta de "Kamikaze Baby" debía pertenecer necesariamente a la generación post Viet-Nam. Enseguida me aclararon que David Benson apenas tiene veintitrés años, que nació en Mansfield, Ohio, y que no ha tomado parte en guerra alguna.

  14. Christopher R. Fee & David A. Leeming. Gods, Heroes, and Kings. The Battle for Mythic Britain

    Directory of Open Access Journals (Sweden)

    Sophie ALATORRE

    2006-06-01

    Full Text Available A reassessment of British mythology has long been overdue, and Gods, Heroes and Kings is to be regarded as a stimulating contribution which helps to situate Anglo-Saxon tales in the mainstream of Medieval literature. Myths, pagan and Judeo-Christian beliefs, classical narratives: such vast material forms the backcloth Christopher F. Fee and David A. Leeming have undertaken to explore, thanks to an erudite comparative approach. Obviously, their book first aims at giving readers a new image of ...

  15. David Hume e as Paixões Indiretas na Sociedade em Rede

    Directory of Open Access Journals (Sweden)

    Tiago Porto

    2017-02-01

    Full Text Available O presente artigo pretende trazer à discussão a importância da Teoria das Paixões desenvolvida por David Hume como um horizonte interpretativo para as ações dos indivíduos conetados às redes sociais da Internet. Para tanto, este trabalho abordará inicialmente o que conhecemos por sociedade em rede e o importante papel desempenhado pela Internet nessa configuração social; em seguida, analisaremos como as paixões indiretas influenciam os indivíduos conectados à rede internacional de computadores

  16. Homeostasis and change: A commentary on Homeostatic Theory of Obesity by David Marks.

    Science.gov (United States)

    DiClemente, Carlo C; Delahanty, Janine

    2016-01-01

    This commentary on David Marks' article on the Homeostatic Theory of Obesity and his Circle of Discontent mechanism for maintaining problematic eating behavior and obesity offers a perspective on the promise and potential of this theory. At the same time, we challenge the author to incorporate more of a process perspective into the theory. This would include greater exploration of how individuals enter and exit this hypothesized Circle of Discontent, how these mechanisms lead to obesity rather than other internalizing or externalizing disorders, and how the interactions among key variables differ for males and females and developmental stages.

  17. Media(ting Textual Therapies in David Lodge’s Therapy and Deaf Sentence

    Directory of Open Access Journals (Sweden)

    Lidia Mihaela Necula

    2011-07-01

    Full Text Available What the present article attempts at is mediating the image of a ‘discarnate man’ who inlays a discursive medium, itself a message. In so doing, it embarks upon two of David Lodge’s novels, Therapy (1995 and Deaf Sentence (2008 respectively as best implying and suggesting for a mode of survival: the exorcising writing act, manifest at the level of the text under the form of diary pages, letters or emails, seems to work as the best therapeutic treatment for depression (personal or textual, so that the poetics of the text is gradually traded for and replaced by the politics of the fictional game.

  18. Buhler, James. Neumeyer, David. Deemer, Rob. Hearing the Movies: Music and Sound in Film History

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Silveira

    2012-05-01

    Full Text Available James Buhler et David Neumeyer sont certainement les auteurs les plus importants à publier sur l’analyse de la musique de film depuis les années quatre-vingt-dix aux Etats-Unis. Entre autres contributions, ils ont édité ensemble (avec Caryl Flinn Music and Cinema, un livre consacré aux différentes perspectives de l’étude de la musique de film. Tous les deux sont professeurs de théorie musicale à l’école de musique de l’université du Texas à Austin (Neumeyer étant aussi professeur à Leslie Wa...

  19. Science for life: a conversation with Nobel laureate David Baltimore. Interview by Barbara J Culliton.

    Science.gov (United States)

    Baltimore, David

    2006-01-01

    As a man with equal interests in science and science policy, David Baltimore has been at the forefront of many of the important debates that have shaped science since the 1970s. Very much engaged in the initial discussions about the use of recombinant DNA technology, Baltimore had a front-row seat as the biotechnology industry developed. He was also a major player in the decision that resulted in funding of the Human Genome Project by the National Institutes of Health (NIH). Baltimore discusses biotechnology, science education, and the need for a strong dialogue among scientists and scholars in the health policy community.

  20. Clássicos versus Keynes: a abordagem formal de David Champernowne

    OpenAIRE

    Cláudia Heller; Jaylson Jair da Silveira

    2012-01-01

    Este texto tem por objetivo ressaltar um aspecto que não tem sido tratado com a devida profundidade na literatura que estuda a formalização da Teoria Geral do Emprego, dos Juros e da Moeda de John Maynard Keynes (1936). Mais precisamente, o texto destaca a estratégia de formalização adotada por David G. Champernowne em seu artigo intitulado "Unemployment, Basic and Monetary: the classical analysis and the keynesian", publicado em 1935-36 na Review of Economic Studies. Chamamos a atenção para ...

  1. Sit Down with Sabin: David Schlegel: Hunting Dark Energy (LBNL Summer Lecture Series)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Sabin; Schlegel, David

    2011-06-22

    Lawrence Berkeley National Laboratory physicist and dark energy hunter David Schlegel chats with Sabin Russell, former San Francisco Chronicle reporter turned Berkeley Lab science writer, June 22, 2011. Their conversation is the first installment of "Sit Down With Sabin," a weekly conversation hosted by Russell. Over the course of five conversations with Berkeley Lab staff this summer, Russell will explore the ups and downs of innovative science — all without the aid of PowerPoint slides. Brought to you by Berkeley Lab Public Affairs.

  2. David Sanders. A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance.

    Directory of Open Access Journals (Sweden)

    Tatiani G. Rapatzikou

    2012-03-01

    Full Text Available David Sanders in his monograph entitled A Divided Poet: Robert Frost, North of Boston, and the Drama of Disappearance (2011 sheds light on the dilemmas, doubts and personal conflicts Frost confronted while composing his poetic collection North of Boston in which some of his most well-known lyrics, such as “Mending Wall,” “After Apple-Picking,” and “The Wood-Pile,” are contained. This book should be considered alongside a number of other publications either in monograph or essay form that app...

  3. Best Practices Case Study: David Weekley Homes - Eagle Springs and Waterhaven, Houston, TX

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-04-01

    Case study describing David Weekley Homes, Houston Division, has qualified more than 1,240 homes for the DOE Builders Challenge. Advanced framed 2x6 walls with open headers and two-stud corners allow more room for R-20 damp sprayed cellulose wall cavity insulation that is covered with R-5 rigid XPS foam. A radiant barrier cuts heat gain in the R-38 insulated vented attics. Draft stopping at fireplace and duct chases and behind tubs, gluing sheetrock to framing, and extensive caulking make for air-tight homes at 3.0 ACH50.

  4. Atomic processes and application in honour of David R. Bates' 60th birthday

    CERN Document Server

    Burke, P G

    2013-01-01

    Atomic Processes and Applications is a collection of review articles that discusses major atomic and molecular processes and their applications to upper atmospheric physics and to astrophysics. The book also serves as a 60th birthday tribute to Dr. David R. Bates. The coverage of the text includes the overview of stratospheric aeronomy; upper atmosphere of the earth; and problems in atmospheric pollution. The book also deals with technical and highly specialized issues including photoionization of atomic systems; atomic structure and oscillator strengths; and atomic scattering computations. Th

  5. The wonder of their voices: The 1946 Holocaust interviews of David Boder (New York: Oxford, 2010).

    Science.gov (United States)

    Rosen, Alan C

    2012-05-01

    Writing a study of psychologist David Boder's 1946 displaced persons (DP) interview project gave me a chance to further document the substantial early response to the Holocaust. This was clearly one important piece of my study, and one that was eminently straightforward. Yet much of the research on Boder's project at the point in time that I carried it out was elliptical, partly because the primary interview materials were coming to light at an astonishing pace, partly because the archive collections were virtually untapped, and partly because of the misconception of Boder and his interview project itself.

  6. Optical pumping production of spin polarized hydrogen

    International Nuclear Information System (INIS)

    Knize, R.J.; Happer, W.; Cecchi, J.L.

    1984-01-01

    There has been much interest recently in the production of large quantities of spin polarized hydrogen in various fields including controlled fusion, quantum fluids, high energy, and nuclear physics. One promising method for the development of large quantities of spin polarized hydrogen is the utilization of optical pumping with a laser. Optical pumping is a process where photon angular momentum is converted into electron and nuclear spin. The advent of tunable CW dye lasers (approx. 1 watt) allow the production of greater than 10 18 polarized atoms/sec. We have begun a program at Princeton to investigate the physics and technology of using optical pumping to produce large quantities of spin polarized hydrogen. Initial experiments have been done in small closed glass cells. Eventually, a flowing system, open target, or polarized ion source could be constructed

  7. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  8. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  9. Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

    Science.gov (United States)

    Naramoto, Satoshi

    2017-12-01

    Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Representations of Reductive Groups : in Honor of the 60th Birthday of David A. Vogan, Jr.

    CERN Document Server

    Trapa, Peter

    2015-01-01

    Over the last forty years, David Vogan has left an indelible imprint on the representation theory of reductive groups.  His groundbreaking ideas have lead to deep advances in the theory of real and p-adic groups, and have forged lasting connections with other subjects, including number theory, automorphic forms, algebraic geometry, and combinatorics. Representations of Reductive Groups is an outgrowth of the conference of the same name, dedicated to David Vogan on his 60th birthday, which took place at MIT on May 19-23, 2014.  This volume highlights the depth and breadth of Vogan's influence over the subjects mentioned above, and point to many exciting new directions that remain to be explored.  Notably, the first article by McGovern and Trapa offers an overview of Vogan's body of work, placing his ideas in a historical context. Contributors: Pramod N. Achar, Jeffrey D. Adams, Dan Barbasch, Manjul Bhargava, Cédric Bonnafé, Dan Ciubotaru, Meinolf Geck, William Graham, Benedict H. Gross, Xuhua He, Jing-Son...

  11. Corpses of Metaphor. Images of Death in David Leavitt and Jamaica Kincaid

    Directory of Open Access Journals (Sweden)

    Fiorenzo Iuliano

    2010-10-01

    Full Text Available This essay analyzes two works, My Brother by Jamaica Kincaid, and "Saturn Street" by David Leavitt, investigating the construction of homosexuality as a process accomplished by resorting to illness (AIDS and death. In both works, indeed, the slow and dramatic course of AIDS amounts to the progressive unveiling of homosexuality as a social threat or a cause of anxiety and repulsion. The two works are set in different contexts: whereas Jamaica Kincaid refers to the problematic situation of homosexuality in the Caribbean, David Leavitt explores the social and cultural scenario of the 1990s Los Angeles, in the wake of a by now ended utopian confidence in science and technology.  This comparative approach helps us understand the political dynamics through which, in different and, to some extents, opposite realities, the social stigma of AIDS worked as a means to construct homosexual identity and set it apart from the sanitized spectrum of normal and sanctioned sexual behaviors. The point I want to make in this essay is that the corpse is used as an effective metaphor for a dehumanized depiction of male homosexual and ill subjects.

  12. The institution of science and the science of institutions the legacy of Joseph Ben-David

    CERN Document Server

    2014-01-01

    The present anthology, edited by Marcel Herbst, is partially based on a conference, held in 2009, to reflect on the legacy of Ben-David, and contains a selection of substantially revised papers, plus four contributions specifically written for this volume. The book focuses on three major lines of Ben-David’s research, namely “Center and Periphery” (Part I), “Role and Ethos” (Part II), and “Organization and Growth” (Part III). In addition, comprehensive introductory (“Prologue”) and concluding chapters (“Epilogue”, Part IV) by Marcel Herbst are provided. The volume addresses the following disciplines: higher education, history and sociology of science, philosophy of science, history of medicine, public administration, policy studies, Jewish studies, and economics. The anthology is one of two new publications on Joseph Ben-David after the special Minerva edition Vol. 25, Numbers 1–2, March 1987, and Gad Freudenthal’s collection of Ben-David’s writings [1991]. The text can be used i...

  13. The eclogites of the Marun Keu complex, Polar Urals (Russia): fluid control on reaction kinetics and metasomatism during high P metamorphism

    Science.gov (United States)

    Molina, José F.; Austrheim, Håkon; Glodny, Johannes; Rusin, Anatolij

    2002-03-01

    The Marun-Keu complex (Polar Urals, Russia) is a poorly known member of a group of high P complexes outcropping along the length of the Uralide orogen. The central and southern parts of the complex are metamorphosed at high P, medium T conditions ( Tmax˜600-650 °C and P˜14-17 kbar) and differ from its northern part and the rest of the Uralian high P complexes which are metamorphosed at blueschist-to-low T eclogite-facies conditions. The Marun-Keu complex consists of Neoproterozoic to Cambrian volcanic-sedimentary sequences with a large variety of intrusive mafic to felsic rocks. Based on the nature of protoliths and the mode of occurrence, it is distinguished: (1) eclogite-facies rocks after intrusive protoliths, which vary from metagabbros to metagranites; (2) eclogitic quartzofeldspathic gneisses; (3) metasomatic eclogites; and (4) amphibolite-eclogite alternations produced by fluid infiltration during uplift. Igneous textures and mineralogy are preserved in non-sheared, intrusive, dry rocks, whereas eclogitization may be complete along centimetre to 10-m-thick shear zones and in domains infiltrated by H 2O-dominated fluids. The most important reaction features are: (1) transformation of igneous diopside (Na˜0.04-0.09 apfu, based on 6 oxygens) into Na-rich diopside and omphacite (Na˜0.24-0.45 apfu) across microfractures and grain boundaries; (2) replacement of plagioclase by tiny aggregates of zoisite/clinozoisite+white mica+garnet (Alm 32-43, Pyr 7-19, Gro 38-60)+kyanite; and (3) double coronas of garnet and orthopyroxene at olivine-clinopyroxene and olivine-plagioclase pseudomorph interfaces and garnet coronas at clinopyroxene-plagioclase pseudomorph interfaces. Eclogitic quartzofeldspathic gneisses display a fine-scale layering of intermediate and felsic rock compositions with omphacite-bearing and omphacite-free assemblages, respectively. Oligoclase is abundant in this type of rocks, coexisting with omphacite in the intermediate rock compositions. The

  14. Our Polar Past

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2009-01-01

    The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

  15. Terahertz polarization imaging

    NARCIS (Netherlands)

    Van der Valk, N.C.J.; Van der Marel, W.A.M.; Planken, P.C.M.

    2005-01-01

    We present a new method to measure the polarization state of a terahertz pulse by using a modified electrooptic sampling setup. To illustrate the power of this method, we show two examples in which the knowledge of the polarization of the terahertz pulse is essential for interpreting the results:

  16. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  17. Polar Science Is Cool!

    Science.gov (United States)

    Weeks, Sophie

    2012-01-01

    Children are fascinated by the fact that polar scientists do research in extremely cold and dangerous places. In the Arctic they might be viewed as lunch by a polar bear. In the Antarctic, they could lose toes and fingers to frostbite and the wind is so fast it can rip skin off. They camp on ice in continuous daylight, weeks from any form of…

  18. Precision Polarization of Neutrons

    Science.gov (United States)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  19. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2018-01-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements. PMID:29503479

  20. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2017-10-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.

  1. Gold Photoluminescence: Wavelength and Polarization Engineering

    DEFF Research Database (Denmark)

    Andersen, Sebastian Kim Hjælm; Pors, Anders Lambertus; Bozhevolnyi, Sergey I.

    2015-01-01

    We demonstrate engineering of the spectral content and polarization of photoluminescence (PL) from arrayed gold nanoparticles atop a subwavelength-thin dielectric spacer and optically-thick gold film, a configuration that supports gap-surface plasmon resonances (GSPRs). Choice of shapes...... and dimensions of gold nanoparticles influences the GSPR wavelength and polarization characteristics, thereby allowing us to enhance and spectrally mold the plasmon-assisted PL while simultaneously controlling its polarization. In order to understand the underlying physics behind the plasmon-enhanced PL, we...

  2. Photonic crystal based polarization insensitive flat lens

    Science.gov (United States)

    Turduev, M.; Bor, E.; Kurt, H.

    2017-07-01

    , attenuators and couplers, where the polarization insensitive focusing without any additional polarization control components plays an important role.

  3. Hierarchical super-structure identified by polarized light microscopy, electron microscopy and nanoindentation: Implications for the limits of biological control over the growth mode of abalone sea shells

    Directory of Open Access Journals (Sweden)

    Schneider Andreas S

    2012-09-01

    Full Text Available Abstract Background Mollusc shells are commonly investigated using high-resolution imaging techniques based on cryo-fixation. Less detailed information is available regarding the light-optical properties. Sea shells of Haliotis pulcherina were embedded for polishing in defined orientations in order to investigate the interface between prismatic calcite and nacreous aragonite by standard materialographic methods. A polished thin section of the interface was prepared with a defined thickness of 60 μm for quantitative birefringence analysis using polarized light and LC-PolScope microscopy. Scanning electron microscopy images were obtained for comparison. In order to study structural-mechanical relationships, nanoindentation experiments were performed. Results Incident light microscopy revealed a super-structure in semi-transparent regions of the polished cross-section under a defined angle. This super-structure is not visible in transmitted birefringence analysis due to the blurred polarization of small nacre platelets and numerous organic interfaces. The relative orientation and homogeneity of calcite prisms was directly identified, some of them with their optical axes exactly normal to the imaging plane. Co-oriented "prism colonies" were identified by polarized light analyses. The nacreous super-structure was also visualized by secondary electron imaging under defined angles. The domains of the super-structure were interpreted to consist of crystallographically aligned platelet stacks. Nanoindentation experiments showed that mechanical properties changed with the same periodicity as the domain size. Conclusions In this study, we have demonstrated that insights into the growth mechanisms of nacre can be obtained by conventional light-optical methods. For example, we observed super-structures formed by co-oriented nacre platelets as previously identified using X-ray Photo-electron Emission Microscopy (X-PEEM [Gilbert et al., Journal of the

  4. [Fluorescence polarization immunoassay of ractopamine].

    Science.gov (United States)

    Zvereva, E A; Shpakova, N A; Zherdev, A V; Kiu, L; Xu, C; Eremin, S A; Dzantiev, B B

    2016-01-01

    A technique was developed for fluorescence polarization immunoassay (FPIA) of ractopamine, a toxic low molecular weight nonsteroidal growth regulator belonging to the most controlled contaminants of food products of animal origin. The assay is based on the competition between a sample containing ractopamine and ractopamine–fluorophore conjugate for binding to antibodies. The competition is monitored via changes in the degree of fluorescence polarization for plane-polarized excitation light, which differs for the free and antibody-bound forms of the conjugate. The optimal assay conditions were established, ensuring a high accuracy and minimal detection limit. The developed assay demonstrated a detection limit of 1 ng/mL and a range of detectable concentrations of 2.3–50 ng/mL, which met the requirements of sanitary control. The duration of the analysis was 10 min. The possible application of the developed FPIA was demonstrated with testing of turkey meat. The speed and simplicity of the proposed assay define its efficiency as a screening tool for safety of foods.

  5. Selective CO2 Capture and High Proton Conductivity of a Functional Star-of-David Catenane Metal-Organic Framework.

    Science.gov (United States)

    Huang, You-Gui; Wu, Shu-Qi; Deng, Wei-Hua; Xu, Gang; Hu, Fa-Lu; Hill, Jonathan P; Wei, Wei; Su, Sheng-Qun; Shrestha, Lok Kumar; Sato, Osamu; Wu, Ming-Yan; Hong, Mao-Chun; Ariga, Katsuhiko

    2017-11-01

    Network structures based on Star-of-David catenanes with multiple superior functionalities have been so far elusive, although numerous topologically interesting networks are synthesized. Here, a metal-organic framework featuring fused Star-of-David catenanes is reported. Two triangular metallacycles with opposite handedness are triply intertwined forming a Star-of-David catenane. Each catenane fuses with its six neighbors to generate a porous twofold intercatenated gyroid framework. The compound possesses exceptional stability and exhibits multiple functionalities including highly selective CO 2 capture, high proton conductivity, and coexistence of slow magnetic relaxation and long-range ordering. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Altitude Control of a Single Degree of Freedom Flapping Wing Micro Air Vehicle (Postprint)

    Science.gov (United States)

    2009-08-01

    NUMBER 62201F 6. AUTHOR(S) David B. Doman, Michael W. Oppenheimer, Michael A. Bolender, and David O. Sigthorsson (AFRL/ RBCA ) 5d. PROJECT NUMBER...NUMBER Control Design and Analysis Branch (AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air Vehicles Directorate Wright

  7. Polarization at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Moffeit, K.C.

    1988-10-01

    The Stanford Linear collider was designed to accommodate polarized electron beams. Longitudinally polarized electrons colliding with unpolarized positrons at a center of mass energy near the Z/sup 0/ mass can be used as novel and sensitive probes of the electroweak process. A gallium arsenide based photon emission source will provide a beam of longitudinally polarized electrons of about 45 percent polarization. A system of bend magnets and a superconducting solenoid will be used to rotate the spins so that the polarization is preserved while the 1.21 GeV electrons are stored in the damping ring. Another set of bend magnets and two superconducting solenoids orient the spin vectors so that longitudinal polarization of the electrons is achieved at the collision point with the unpolarized positrons. A system to monitor the polarization based on Moller and Compton scattering will be used. Nearly all major components have been fabricated and tested. Subsystems of the source and polarimeters have been installed, and studies are in progress. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. 8 refs., 16 figs., 1 tab.

  8. Activation and polar sequestration of PopA, a c-di-GMP effector protein involved in Caulobacter crescentus cell cycle control

    DEFF Research Database (Denmark)

    Ozaki, Shogo; Schalch-Moser, Annina; Zumthor, Ludwig

    2014-01-01

    When Caulobacter crescentus enters S-phase the replication initiation inhibitor CtrA dynamically positions to the old cell pole to be degraded by the polar ClpXP protease. Polar delivery of CtrA requires PopA and the diguanylate cyclase PleD that positions to the same pole. Here we present evidence...... that PopA originated through gene duplication from its paralogue response regulator PleD and subsequent co-option as c-di-GMP effector protein. While the C-terminal catalytic domain (GGDEF) of PleD is activated by phosphorylation of the N-terminal receiver domain, functional adaptation has reversed signal......A to the cell pole in response to c-di-GMP binding. In agreement with the divergent activation and targeting mechanisms, distinct markers sequester PleD and PopA to the old cell pole upon S-phase entry. Together these data indicate that PopA adopted a novel role as topology specificity factor to help recruit...

  9. Polarized atomic beams for targets

    International Nuclear Information System (INIS)

    Grueebler, W.

    1984-01-01

    The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

  10. Polarized scintillator targets

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    2000-05-01

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as "live" polarized targets in nuclear physics experiments.

  11. Polarized scintillator targets

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den E-mail: vandenbrandt@psi.ch; Bunyatova, E.I.; Hautle, P.; Konter, J.A.; Mango, S

    2000-05-21

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as 'live' polarized targets in nuclear physics experiments.

  12. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  13. Ultra-thin, single-layer polarization rotator

    Directory of Open Access Journals (Sweden)

    T. V. Son

    2016-08-01

    Full Text Available We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal. Changes in refractive indices create unequal phase shifts on s- and p-polarization components of incident light, and rotation of linear polarization shows intensity modulation by a factor of 103 when transmitted through polarizers. This makes possible polarization rotation devices as thin as 50 nm that would be activated thermally, optically or electrically.

  14. EDITORIAL: Van der Waals interactions in advanced materials, in memory of David C Langreth Van der Waals interactions in advanced materials, in memory of David C Langreth

    Science.gov (United States)

    Hyldgaard, Per; Rahman, Talat S.

    2012-10-01

    sufficiently close to any corrugated—and/or any smooth—surface and thus enforce a strong vdW-type adhesion; it exploits what is then essentially a contact force (dominated by the attraction exerted in the near-surface regions) to defy the pull of gravity on its own bulk. This Journal of Physics: Condensed Matter special issue is dedicated to the memory of David C Langreth. David is a dearly missed friend and mentor who inspired many of us. He was an outstanding condensed matter theorist and a scholar who greatly influenced us through his many-particle-physics based insights into density functional theory (DFT), surface science and related areas. His seminal works range from conserving formulations of interacting nonequilibrium transport [1] and formal-scattering theory [2] to an explicit formulation [3] of the exact DFT exchange-correlation energy in the adiabatic connection formula (ACF), the latter also being derived independently by Gunnarsson and Lundqvist [4]. David's portfolio also includes an analysis [5] that helped catalyze and guide the development of DFT from the local-density approximation (LDA) to the formulations of generalized gradient approximations (GGAs). Another salient contribution of David's is in the area of vdW interactions in materials. He was a key architect of the vdW density functional (vdW-DF) method [6, 7]. This method was developed in a long-standing Rutgers-Chalmers collaboration between David's group and that of Bengt I Lundqvist, later extending to a wider group of researchers on both sides of the Atlantic. Plasmons are collective excitations that depend on electron-density variation. The plasmon response can be seen as defining the nature of the LDA [4] and their description can thus also be seen as contributing to the success of GGA. The vdW-DF method is a regular constraint-based density functional (for ground-state DFT) which is derived within the ACF framework and which emphasizes the electrodynamical nature of the coupling between

  15. Capitalismo, cidade e política na perspectiva de David Harvey

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Santana

    2013-06-01

    Full Text Available O texto discute alguns eixos conceituais relevantes para a compreensão da obra de David Harvey, concentrando-se especificamente nas formulações do autor acerca da ideia de rearranjo espacial (spatial fix, de novo imperialismo (new imperialism e de acumulação mediante despossessão (acumulation by dispossession. Objetiva-se lidar também com o que se seriam os componentes da teoria critica de Harvey. Além disso, apresenta-se como tais ideias e formulações não podem ser plenamente entendidas sem o seu enraizamento nas reflexões do autor acerca das cidades.

  16. David Hume e as finanças de James I

    Directory of Open Access Journals (Sweden)

    ROGERIO ARTHMAR

    2015-09-01

    Full Text Available RESUMOEste artigo examina a análise de David Hume realizada em seu livro História da Inglaterra, da luta entre o parlamento e o rei James I sobre as finanças da coroa durante o primeiro trimestre do século XVII. Inicialmente, são apresentados os principais elementos políticos por trás da briga no coração do poder político da Inglaterra, seguidos por comentários do escritor escocês sobre as finanças reais, com ênfase nos seus pontos de vista sobre as receitas e despesas da Coroa durante o reinado de James I. No final são recuperados os fatores de longo prazo elencados como determinantes da nova postura parlamentar.

  17. Rigoulet-Roze David, Géopolitique de l’Arabie Saoudite

    Directory of Open Access Journals (Sweden)

    Laurent Bonnefoy

    2007-12-01

    Full Text Available Depuis quelques années, l’Arabie Saoudite suscite un intérêt grandissant de la part des chercheurs et des experts occidentaux. Rares sont néanmoins les écrits qui à l’information collectée sur le terrain allient une démarche rigoureusement construite. C’est à juste titre que David Rigoulet-Roze rappelle dans son introduction la nécessité de dépasser les « lieux communs » et d’adopter « une perspective véritablement géopolitique, avec les outils et la méthode » (p. 8 que cela implique. Il est...

  18. The reconstitution of political theory: David Easton, behavioralism, and the long road to system.

    Science.gov (United States)

    Gunnell, John G

    2013-01-01

    During the last half of the twentieth century, the concept of system was arguably the most important concept in the theoretical repertoire of the discipline of American political science. Although systems analysis was broadly employed in the behavioral sciences, David Easton's work was particularly influential in the study of politics. This is in part because he attempted to develop a distinct account of the political system that was not theoretically subservient either to general systems theory or to conceptions of the social system such as that advanced by Talcott Parsons. Although a great deal of attention has been devoted to Easton's theory, the origins and evolution of the system concept in his work have not been carefully reconstructed and analyzed. © 2013 Wiley Periodicals, Inc.

  19. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 1

    International Nuclear Information System (INIS)

    1996-10-01

    This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may be necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels

  20. David M. Lubin. Shooting Kennedy : JFK and the Culture of Images.

    Directory of Open Access Journals (Sweden)

    François Brunet

    2006-04-01

    Full Text Available Voici un livre décapant, décoiffant et déroutant, qui a d’ores et déjà fait pas mal de bruit outre-Atlantique. Son auteur, David Lubin, enseigne l’histoire de l’art à Wake Forest (Caroline du Nord, et il était déjà connu des américanistes comme l’auteur de Picturing a Nation : Art and Social Change in Nineteenth-Century America (1994. Dans ce dernier livre, comme dans Titanic (1999, Lubin se montrait un historien de l’art novateur, voire iconoclaste, en organisant la confrontation des genr...

  1. The Dehumanizing American Dream in David Mamet’s Glengarry Glen Ross

    Directory of Open Access Journals (Sweden)

    Mehdi Sepehrmanesh

    2014-01-01

    Full Text Available The American Dream is a recurrent theme in American literature. In this response, this paper is an attempt to expose the destructive effects of the dream on the human spirit. It is also shown, through the analysis of David Mamet’s glengarry Glen Ross, that despite the promise of the dream it contains many contradictions. Beneath the seeming simple surface of the play lies a deep current of meanings that reflect the calamities of modern American life, and in a broader sense, the modern world. This article indicates how capitalism inculcates ideologies in the mind of individuals in order to facilitate the exploiting process and unquestioning subordination. Ragged individualism, for instance, as  the most prominent of these ideologies, disrupts all communal bonds and even exceeds to the disintegration of friendship and family life.

  2. From nuclear submarines to graduate medical education: applying David Marquet's intent-based leadership model.

    Science.gov (United States)

    Fernandez-Salvador, Camilo; Oney, Rebecca; Song, Sungjin A; Camacho, Macario

    2017-10-11

    L. David Marquet, a decorated Navy Captain, transformed an underperforming submarine crew by empowering his subordinates to be leaders and reach their full potential. He called this intent-based leadership (IBL). What would happen if Marquet's model were implemented in Graduate Medical Education (GME)?In this letter to the editor, we summarize the potential of the IBL model in graduate medical education as opposed to the traditional leader-follower method. IBL harnesses human productivity toward the shared goals of GME, which are patient care and trainee learning. This shift in mindset could lead both teachers and trainees to focus more on the real reason that we undertake GME and change behaviors for the better. We suggest that IBL can and should be adopted in GME and propose that both patients and providers will benefit from this action.

  3. Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may be necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels.

  4. Modeling Instruction of David Hestenes: a proposal of thematic modeling cycle and discussion of scientific literacy

    Directory of Open Access Journals (Sweden)

    Ednilson Sergio Ramalho de Souza

    2016-07-01

    Full Text Available The pedagogical work with mathematical modeling assumes investigate situations of reality. However, mental models formed from the contact with the experiential world are generally incompatible with the conceptual models. So David Hestenes supports the view that one of the biggest challenges of teaching and learning in science and mathematics is to coordinate conceptual models with mental models, which led to the elaboration of a didactic in mathematical modeling: Modeling Instruction. Our goal is to present a proposal for thematic modeling cycle drawn up in hestenesianos assumptions and discuss possibilities for scientific literacy. The main question was to know how to emerge indicators for scientific literacy for the proposed cycle. This is a bibliographic research in order to identify the available literature contributions on the subject and raise the possibility and challenges for the brazilian teaching science and mathematics. Preliminary results indicate that the proposed modeling cycle can develop indicators for scientific literacy of different natures.

  5. David Hartley's views on Madness: With an introduction by GE Berrios.

    Science.gov (United States)

    Berrios, G E

    2015-03-01

    The psychiatric aspects of David Hartley's writings have received less attention than the rest of his work. This Classic Text deals with Section VI of his Observations on Man …, namely, the 'Imperfections of the rational Faculty'. Hartley defines madness as an imperfection of reason that can be temporary or enduring. He makes use of his model of mental functioning to differentiate between eight clinical categories of madness, each representing a different pattern of vibrations of the nerves. Hartley developed this model based on Newton's theory of vibrations and, to explain the complexity of mental acts and entities, he combined it with his own version of the mechanism of Association of Ideas borrowed from John Locke. Much work needs to be done to identify the provenance of Hartley's nosology and nosography. © The Author(s) 2015.

  6. Calculating degree-based topological indices of dominating David derived networks

    Science.gov (United States)

    Ahmad, Muhammad Saeed; Nazeer, Waqas; Kang, Shin Min; Imran, Muhammad; Gao, Wei

    2017-12-01

    An important area of applied mathematics is the Chemical reaction network theory. The behavior of real world problems can be modeled by using this theory. Due to applications in theoretical chemistry and biochemistry, it has attracted researchers since its foundation. It also attracts pure mathematicians because it involves interesting mathematical structures. In this report, we compute newly defined topological indices, namely, Arithmetic-Geometric index (AG1 index), SK index, SK1 index, and SK2 index of the dominating David derived networks [type="bibr" rid="j_phys-2017-0126_ref_001">1, type="bibr" rid="j_phys-2017-0126_ref_002">2, type="bibr" rid="j_phys-2017-0126_ref_003">3, type="bibr" rid="j_phys-2017-0126_ref_004">4, type="bibr" rid="j_phys-2017-0126_ref_005">5].

  7. Review essay on David Laibman, Deep History: A Study in Social Evolution and Human Potential

    Directory of Open Access Journals (Sweden)

    Altug Yalcintas

    2011-11-01

    Full Text Available While historical materialism and evolutionism provide similar explanations and ideas regarding the cause of long-term social change, the two theories are rarely used in conjunction with one another. In Deep History,the author David Laibman addresses some of the standard questions of evolutionary social theory and attempts to bridge the two concepts, by showing that historical and materialist explanations are present in both Marxian and evolutionary interpretations of history. His goal: develop a Marxist theory of history from an evolutionist perspective, and surmount the traditional confines of historical materialism, so as to embrace evolutionary conceptions in explaining social change. However, the unbalanced research methodology limits the reach and depth of Laibman’s contribution. The two main shortcomings of his work are discussed in the following sections: The Audience Problem and The Evolutionary Problem.

  8. Fairness and Respect in Obesity Prevention Policies: A Response to David Buchanan

    Directory of Open Access Journals (Sweden)

    Katherine King

    2014-01-01

    Full Text Available In his response to our article (1,2, David Buchanan introduces some useful and important distinctions in the concepts of equality and autonomy. He highlights, for example, the distinction between inequality and inequity, which captures the insight that not all differences between people are unjust. Unjust inequalities are a subset of differences between people, and theories of justice can be defined by how they determine which of these differences are unjust. In addition, he points out that autonomy is not simply a matter of negative liberty, but also about a positive capacity to act. This understanding of autonomy is consistent with the account we offered in the paper, which underlines the importance of both the capacity to understand available options, and the capacity to act on the choices that one makes.

  9. Hacking the aesthetic: David Haines and Joyce Hinterding's new ecologies of signal

    Directory of Open Access Journals (Sweden)

    Andrew Murphie

    2012-06-01

    Full Text Available Award winning Australian electronic artists David Haines and Joyce Hinterding's installation work is discussed as “signal-work.” Their work reconfigures signal within original assemblages involving subtle audio, high resolution video (both recorded and animated, kilometers of coiled copper wire, antennae or home-built electronics, electrostatic disturbances, the like of very low frequency radiation from the Milky Way, and cross-signal processing. The article develops a context for thinking about the work in terms of Whitehead's process philosophy, as this is relevant to media theory, as well as concepts of plural ecology and ongoing differentiation drawn from Bateson and Guattari. Signal processing is seen as key to all this. The article argues that in Hinterding and Haines’ signal-work new sensations are produced, outside of the normal “syntax” of some models of aesthetic experience. This challenges some aspects of thinking about both aesthetics and political ecology.

  10. Le tâtonnement dans Reader’s Block (1996) de David Markson

    OpenAIRE

    Duplay, Mathieu

    2013-01-01

    Roman de l’ombre, Reader’s Block de David Markson raconte entre autres choses l’effacement de la subjectivité, réduite à presque rien dans un monde gagné par les ténèbres où l’écriture même, faute de lumière, devient peu à peu indéchiffrable. Ainsi, le blocage de la lecture qu’évoque le titre traduit moins une crise herméneutique qu’il ne résulte d’une incapacité physique, de la perte de contact avec l’écrit dans sa dimension matérielle, comme le rappellent aussi les allusions fréquentes à la...

  11. M-Polynomials and Topological Indices of Dominating David Derived Networks

    Directory of Open Access Journals (Sweden)

    Kang Shin Min

    2018-03-01

    Full Text Available There is a strong relationship between the chemical characteristics of chemical compounds and their molecular structures. Topological indices are numerical values associated with the chemical molecular graphs that help to understand the physical features, chemical reactivity, and biological activity of chemical compound. Thus, the study of the topological indices is important. M-polynomial helps to recover many degree-based topological indices for example Zagreb indices, Randic index, symmetric division idex, inverse sum index etc. In this article we compute M-polynomials of dominating David derived networks of the first type, second type and third type of dimension n and find some topological properties by using these M-polynomials. The results are plotted using Maple to see the dependence of topological indices on the involved parameters.

  12. David Mitrany and South-East Europe: The Balkan Key to World Peace

    Directory of Open Access Journals (Sweden)

    Lucian M. Ashworth

    2006-01-01

    Full Text Available Today David Mitrany is best known for his work on international functionalism, which influenced the development of European integration and the organisation of United Nations specialised agencies. What is often ignored in the West is his work on South-East Europe. During the inter-war period Mitrany studied both the operation of war government and the subsequent peasant revolution in the Balkans. War government demonstrated that political organisation could bridge the gap between social action and private property, while the peasant social revolution showed that the abstract economics associated with both capitalist and Marxist economics was not applicable outside of urban industrial production. It was through his studies of South-East Europe that Mitrany drew many of the lessons and concepts that were to form the foundations of his international theory.

  13. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H.B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  14. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest

    2012-01-01

    Time-domain-induced polarization has significantly broadened its field of reference during the last decade, from mineral exploration to environmental geophysics, e.g., for clay and peat identification and landfill characterization. Though, insufficient modeling tools have hitherto limited the use...... of time-domaininduced polarization for wider purposes. For these reasons, a new forward code and inversion algorithm have been developed using the full-time decay of the induced polarization response, together with an accurate description of the transmitter waveform and of the receiver transfer function......%. Furthermore, the presence of low-pass filters in time-domain-induced polarization instruments affects the early times of the acquired decays (typically up to 100 ms) and has to be modeled in the forward response to avoid significant loss of resolution. The developed forward code has been implemented in a 1D...

  15. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  16. David Roberts en Córdoba. Vistas de paisaje y arquitectura hacia 1833

    Directory of Open Access Journals (Sweden)

    Gámiz Gordo, Antonio

    2015-12-01

    Full Text Available David Roberts' views of Córdoba were carried out in 1833 and later redrafted as lithographs, engravings, and oils. These artworks enjoyed great commercial success and international diffusion due to their thematic and undoubted artistic value. The authors analyze their documentary value as a graphic record -prior to the advent of photography- of the urban landscape and architecture of Cordoba, a city now denominated a World Heritage Site. These images are studied here for the first time as a group, since they are either virtually untraceable or dispersed in museums throughout the world. In addition, these views have been contextualized with information concerning the artist and his Spanish journey, including a letter that he wrote from Córdoba. The documentary reliability of every image is also assessed, while the significant transformations of the places represented are indicated.Las vistas realizadas en Córdoba por David Roberts en 1833, reelaboradas como litografías, grabados y óleos, han gozado de gran éxito comercial y difusión internacional por su temática e indudable interés artístico. Esta investigación profundiza en su valor documental como registros gráficos previos a la aparición de la fotografía, del paisaje y la arquitectura de una ciudad hoy considerada Patrimonio de la Humanidad. Las imágenes presentadas se analizan por primera vez como conjunto, pues algunas son de difícil localización o están dispersas en museos de todo el mundo, y se contextualizan con datos sobre el pintor y su viaje por España, considerando una carta que éste escribió desde Córdoba. También se valora la fiabilidad documental de cada vista, a la vez que se detectan significativas transformaciones de los lugares representados.

  17. The polarized platypus polarized neutron reflectometry made possible

    International Nuclear Information System (INIS)

    Saerbeck, Thomas

    2009-01-01

    Full text: The magnetic moment of the neutron, together with it's highly penetrating non destructive manner, make polarized neutron reflectometry an excellent tool to study magnetic phenomena across surfaces and interfaces of thin films. Unlike other magnetometry techniques which ordinarily yield only average magnetization values or, in case of probes with higher spatial resolution (e.g. electron microscopy or scanning tunnelling microscopy), show a high surface sensitivity, PNR together with magnetic x-ray scattering provides the ability to spatially resolve vector magnetization well beneath the surface [1] The ability to obtain vector magnetization profiles across interfaces and surfaces of thin films and multilayers offers the intriguing possibility to study systematically magnetic configurations and magnetic exchange interactions through intervening layers. In this paper we present the performance of the new polarization system installed on the time of flight neutron reflectometer PLATYPUS at ANSTO's Bragg Institute. The spin state of the neutrons is polarized and analysed by spatial separation of different neutron spin states using polarizing Fe/Si supermirrors before, and after the sample stage. The supermirrors have a large wavelength acceptance bandwidth of 3 A to 12 A. To control the desired spin direction of the incoming and reflected beam from the sample, two sets of RF spin flippers are installed. In the free space between the spin flippers and the sample stage the neutron spin direction is maintained by two sets of magnetic guide field coils. The new sample environment for studies of magnetic samples includes a 1 T electromagnet and a closed cycle refrigerator which gives access to a temperature range from 4K to 3 50 K .

  18. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  19. Ultracold Polar Molecules

    Science.gov (United States)

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0005 Ultracold Polar Molecules Jeremy Hutson UNIVERSITY OF DURHAM Final Report 04/01/2016 DISTRIBUTION A: Distribution approved...DATES COVERED (From - To) 15-Jan-2010 to 14-Jul-2015 4. TITLE AND SUBTITLE Final Report on Grant FA8655-10-1-3033 on Ultracold Polar Molecules 5a...formation of ultracold 87RbCs molecules in their rovibrational ground state by magnetoassociation followed by STIRAP, resulting in 14 papers acknowledging

  20. Hsp Polarization Verification

    Science.gov (United States)

    Bless, Robert

    1991-07-01

    This proposal defines the procedure for determining the instrumental polarization of the polarimetric IDT (IDT#1, POL) on the HSP. 1 of 2 unpolarized standard stars wil be observed using various filter-polarizer combinations. These observations will permit the instrumental polarization to be calibrated. The instrumental polarization must be determined to a high precision in order to vectoriallly remove it from HSP polarization observations to determine the actual astronomical polarization. Final run of proposal will look at one of 2 possible stars previously observed to get another look at the throughput. Revision History: Mark H. Slovak 8/30/88 Translated to V2 proposal instructions (RPSS V6.2) S. Laurent 1/20/89 Updated: Sally Laurent 2/24/89, 3/20/89, 4/13/89, 5/12/89 Modified: P. Stanley 1/15/90 - change to use CTA selected targets only; Fixes for aberration problem - SALM 7/30/90; Based on SV/HSP 1386. New submission changed targets and revised scheduling strategy. Revised: 26 Aug 92 J. Dolan, L. Walter, P. Reppert want to re-run the proposal (3985) one last time to bring down errors.

  1. Beautiful Piles of Bones: An Interview with 2017 Genetics Society of America Medal Recipient David M. Kingsley.

    Science.gov (United States)

    Kingsley, David M

    2017-12-01

    The Genetics Society of America Medal is awarded to an individual for outstanding contributions to the field of genetics in the last 15 years. Recipients of the GSA Medal are recognized for elegant and highly meaningful contributions to modern genetics, exemplifying the ingenuity of GSA membership. The 2017 recipient is David M. Kingsley, whose work in mouse, sticklebacks, and humans has shifted paradigms about how vertebrates evolve. Kingsley first fell in love with genetics in graduate school, where he worked on receptor mediated endocytosis with Monty Krieger. In his postdoctoral training he was able to unite genetics with his first scientific love: vertebrate morphology. He joined the group of Neal Copeland and Nancy Jenkins, where he led efforts to map the classical mouse skeletal mutation short ear Convinced that experimental genetics had a unique power to reveal the inner workings of evolution, Kingsley then established the stickleback fish as an extraordinarily productive model of quantitative trait evolution in wild species. He and his colleagues revealed many important insights, including the discoveries that major morphological differences can map to key loci with large effects, that regulatory changes in essential developmental control genes have produced advantageous new traits, and that nature has selected the same genes over and over again to drive the stickleback's skeletal evolution. Recently, Kingsley's group has been using these lessons to reveal more about how our own species evolved.This is an abridged version of the interview. The full interview is available on the Genes to Genomes blog, at genestogenomes.org/kingsley/. Copyright © 2017 by the Genetics Society of America.

  2. Work plan for the removal and subsequent management of specific waste from David Witherspoon, Inc., Knoxville, Tennessee

    International Nuclear Information System (INIS)

    1993-01-01

    The Tennessee Department of Environment and Conservation (TDEC) and the Department of Energy (DOE) have made the determination that approximately 258 drums of waste and 10 open-top boxes of waste now located at the site known as David Witherspoon, Inc., (DWI) in south Knoxville, Tennessee, should be repackaged as necessary and transferred to the K-25 Site in Oak Ridge, Tennessee, for management. This work plan addresses the four phases of activity planned and the methods of accomplishment The lint phase will consist of an assessment to determine requirements for managing the waste. Items to be investigated include site access, site conditions, personal protective equipment, waste characterization needs, packaging and labeling, transportation, receipt and storage of the waste at the K-25 Site, and site controls and monitoring required during the packaging operations to be conducted at DWI. The second phase will include mobilization of on-site support and operating facilities, sampling and transferral of a randomly selected representative fraction of the 232 drums now stored on-site in sea/land containers to storage facilities at the K-25 Site, and sampling of the waste now stored in the 26 drums inside the main process building and the 10 open-top boxes of waste stored outside and adjacent to the building. The third phase will include repackaging and transferral of the 26 drums and 10 boxes of waste to the K-25 Site and placement of the containerized waste into appropriate storage at the K-25 Site. Participants in the fourth phase of activity will demobilize the support and operating facilities from DWI, conduct an on-site evaluation at the K-25 site to verify compliance with storage and other management requirements, prepare a closeout report for the activity assessing the actions, and develop a plan for the final management method for the waste

  3. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  4. "And This Is How You Shall Ask": Linguistics, Anthropology, and Education in the Work of David Smith

    Science.gov (United States)

    Gilmore, Perry; McDermott, Ray

    2006-01-01

    This article celebrates the life and work of David M. Smith, former Council on Anthropology and Education president and founder of the University of Pennsylvania Ethnography in Education Research Forum, tracing his contributions to the fields of linguistics, anthropology, and education through the dual lens of his ten research principles and Walt…

  5. Theorising "Geo-Identity" and David Harvey's Space: School Choices of the Geographically Bound Middle-Class

    Science.gov (United States)

    Rowe, Emma

    2015-01-01

    This paper draws on David Harvey's theories of absolute and relational space in order to critique geographically bound school choices of the gentrified middle-class in the City of Melbourne, Australia. The paper relies on interviews with inner-city school choosers as generated by a longitudinal ethnographic school choice study. I argue that the…

  6. Religious Literacy or Spiritual Awareness? Comparative Critique of Andrew Wright's and David Hay's Approaches to Spiritual Education

    Science.gov (United States)

    Filipsone, Anta

    2009-01-01

    On the basis of a comparison of the educational approaches of Andrew Wright and David Hay this paper illustrates the persisting problem of dichotomising cognitive and trans-cognitive aspects of spiritual development and education. Even though both Wright and Hay speak of the same topic--spirituality and spiritual education--they define these terms…

  7. ‘A Wistful Dream of Far-Off Californian Glamour’: David Sylvester and the British View of American Art

    Directory of Open Access Journals (Sweden)

    James Finch

    2017-05-01

    Full Text Available David Sylvester’s criticism from the 1950s and 1960s combined enthusiasm for the vitality of new American art with ambivalence about its influence on British artists. This essay investigates Sylvester’s complex attitude towards American art through his writing, broadcasting and artist interviews.

  8. Preserving Precious Instruments in Mathematics History: The Educational Museum of Teachers College and David Eugene Smith's Collection

    Science.gov (United States)

    Murray, Diane R.

    2011-01-01

    A history is given of the Educational Museum of Teachers College, which began in 1886, and David Eugene Smith's extensive collection of mathematical tools used in the Museum's exhibits is discussed. Historic mathematical instruments including, the astrolabe, abacus and counting rods, and the slide rule are examined. The author uses digitized…

  9. Unfulfilled Potential: The Adult Careers of Former Musical Prodigies Ervin Nyiregyhazi, Fanny Mendelssohn Hensel, and David Helfgott

    Science.gov (United States)

    Jung, Jae Yup

    2015-01-01

    This study investigated the careers of three former musical prodigies (i.e., Ervin Nyiregyhazi, Fanny Mendelssohn Hensel, and David Helfgott) who made mature decisions to pursue music as a career, but did not achieve at the expected levels of distinction as adults. Many of the individual factors that may contribute to their relative lack of adult…

  10. The evolution of tensor polarization

    International Nuclear Information System (INIS)

    Huang, H.; Lee, S.Y.; Ratner, L.

    1993-01-01

    By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

  11. Los actos tienen consecuencias. Lógicas del mind-game film en la trilogía de Los Ángeles de David Lynch

    NARCIS (Netherlands)

    Elsaesser, T.

    2013-01-01

    Actions Do Have Consequences. Logics of the Mind-Game Film in David Lynch’s Los Angeles-Trilogy. David Lynch is a director, along with other auteurs, notably Michael Haneke and Lars von Trier, whose authorial identity and creative authority —and the challenges these encounter in the 21st century—

  12. Polarized Electrons at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, C.K.

    1997-12-31

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

  13. Polarized electrons at Jefferson laboratory

    International Nuclear Information System (INIS)

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented

  14. Dynamics and Control of a Biomimetic Vehicle Using Biased Wingbeat Forcing Functions: Part 1 - Aerodynamic Model (Postprint)

    Science.gov (United States)

    2010-01-01

    5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62201F 6. AUTHOR(S) David B. Doman, Michael W. Oppenheimer, and David O. Sigthorsson (AFRL/ RBCA ...ORGANIZATION REPORT NUMBER Control Design and Analysis Branch (AFRL/ RBCA ) Control Sciences Division Air Force Research Laboratory, Air

  15. Polar low monitoring

    Science.gov (United States)

    Bobylev, Leonid; Zabolotskikh, Elizaveta; Mitnik, Leonid

    2010-05-01

    Polar lows are intense mesoscale atmospheric low pressure weather systems, developing poleward of the main baroclinic zone and associated with high surface wind speeds. Small size and short lifetime, sparse in-situ observations in the regions of their development complicate polar low study. Our knowledge of polar lows and mesocyclones has come almost entirely during the period of satellite remote sensing since, by virtue of their small horizontal scale, it was rarely possible to analyse these lows on conventional weather charts using only the data from the synoptic observing network. However, the effects of intense polar lows have been felt by coastal communities and seafarers since the earliest times. These weather systems are thought to be responsible for the loss of many small vessels over the centuries, although the nature of the storms was not understood and their arrival could not be predicted. The actuality of the polar low research is stipulated by their high destructive power: they are a threat to such businesses as oil and gas exploration, fisheries and shipping. They could worsen because of global warming: a shrinking of sea ice around the North Pole, which thawed to its record minimum in the summer of 2007, is likely to give rise to more powerful storms that form only over open water and can cause hurricane-strength winds. Therefore, study of polar lows, their timely detection, tracking and forecasting represents a challenge for today meteorology. Satellite passive microwave data, starting from Special Sensor Microwave Imager (SSM/I) onboard Defense Meteorological Satellite Program (DMSP) satellite, remain invaluable source of regularly available remotely sensed data to study polar lows. The sounding in this spectral range has several advantages in comparison with observations in visible and infrared ranges and Synthetic Aperture Radar (SAR) data: independence on day time and clouds, regularity and high temporal resolution in Polar Regions. Satellite

  16. The Bochum Polarized Target

    International Nuclear Information System (INIS)

    Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

    2001-01-01

    The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

  17. In-line Fiber Polarizer

    OpenAIRE

    Perumalsamy, Priya

    1998-01-01

    Polarizers and polarization devices are important components in fiber optic communication and sensor systems. There is a growing need for efficient low loss components that are compatible with optical fibers. An all fiber in-line polarizer is a more desirable alternative that could be placed at appropriate intervals along communication links. An in-line fiber polarizer was fabricated and tested. The in-line fiber polarizer operates by coupling optical energy propagatin...

  18. A modular designed ultra-high-vacuum spin-polarized scanning tunneling microscope with controllable magnetic fields for investigating epitaxial thin films.

    Science.gov (United States)

    Wang, Kangkang; Lin, Wenzhi; Chinchore, Abhijit V; Liu, Yinghao; Smith, Arthur R

    2011-05-01

    A room-temperature ultra-high-vacuum scanning tunneling microscope for in situ scanning freshly grown epitaxial films has been developed. The core unit of the microscope, which consists of critical components including scanner and approach motors, is modular designed. This enables easy adaptation of the same microscope units to new growth systems with different sample-transfer geometries. Furthermore the core unit is designed to be fully compatible with cryogenic temperatures and high magnetic field operations. A double-stage spring suspension system with eddy current damping has been implemented to achieve ≤5 pm z stability in a noisy environment and in the presence of an interconnected growth chamber. Both tips and samples can be quickly exchanged in situ; also a tunable external magnetic field can be introduced using a transferable permanent magnet shuttle. This allows spin-polarized tunneling with magnetically coated tips. The performance of this microscope is demonstrated by atomic-resolution imaging of surface reconstructions on wide band-gap GaN surfaces and spin-resolved experiments on antiferromagnetic Mn(3)N(2)(010) surfaces.

  19. Political Competition and Polarization

    DEFF Research Database (Denmark)

    Schultz, Christian

    This paper considers political competition and the consequences of political polarization when parties are better informed about how the economy functions than voters are. Specifically, parties know the cost producing a public good, voters do not. An incumbent's choice of policy acts like a signa...... for costs before an upcoming election. It is shown that the more polarized the political parties the more distorted the incumbent's policy choice.......This paper considers political competition and the consequences of political polarization when parties are better informed about how the economy functions than voters are. Specifically, parties know the cost producing a public good, voters do not. An incumbent's choice of policy acts like a signal...

  20. Physics of polarized targets

    CERN Document Server

    Niinikoski, Tapio

    2014-01-01

    For developing, building and operating solid polarized targets we need to understand several fields of physics that have seen sub stantial advances during the last 50 years. W e shall briefly review a selection of those that are important today. These are: 1) quantum statistical methods to describe saturation and relaxation in magnetic resonance; 2) equal spin temperature model for dy namic nuclear polarization; 3 ) weak saturation during NMR polarization measurement; 4 ) refrigeration using the quantum fluid properties of helium isotopes. These, combined with superconducting magnet technologies, permit today to reach nearly complete pola rization of almost any nuclear spins. Targets can be operated in frozen spin mode in rather low and inhomogeneous field of any orientation, and in DNP mode in beams of high intensity. Beyond such experiments of nuclear and particle physics, applications a re also emerging in macromolecular chemistry and in magnetic resonance imaging. This talk is a tribute to Michel Borghini...