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Sample records for jrvi magnus kallas

  1. Site investigation for Magnus

    SciTech Connect

    Semple, R.M.; Rigden, W.J.

    1983-05-01

    In April 1982, BP's Magnus structure was installed about 150 km northeast of the Shetland Islands. The most northerly, deepest water platform in the North Sea, the steel tower is supported on groups of 2 m diameter piles that were driven, in good accordance with predictions, to an average penetration of 85 m in strong cohesive soils. The paper describes investigations performed at the platform site, and documents soil characteristics for conventional and state of the art pile analyses. Reference is made to several innovative techniques first used at the Magnus site that have since been incorporated into the larger North Sea investigations. Information is given about the geological history of the site. Test results are presented on soil strength and stiffness, including critical state soil mechanics parameters, on residual pore pressures after sampling, and on the effect of sample size on strength characteristics.

  2. Rotary and Magnus balances

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.

    1981-01-01

    Two wind tunnel techniques for determining part of the aerodynamic information required to describe the dynamic bahavior of various types of vehicles in flight are described. Force and moment measurements are determined with a rotary-balance apparatus in a coning motion and with a Magnus balance in a high-speed spinning motion. Coning motion is pertinent to both aircraft and missiles, and spinning is important for spin stabilized missiles. Basic principles of both techniques are described, and specific examples of each type of apparatus are presented. Typical experimental results are also discussed.

  3. Magnus effect power generator

    SciTech Connect

    Borg, J.L.; Borg, C.J.

    1984-05-01

    Magnus cylinders are mounted for rotation at right angles to shafts that are revolved about a generally vertical axis. The shafts are free to rotate 180/sup 0/. The Magnus cylinders are continuously rotated in the same angular direction. At one position of revolution of the shafts, the cylinders rotate on an axis generally parallel to the axis of revolution of the shafts. When the apparatus is immersed in a fluid flow (gaseous or liquid) a torque of rotation is developed when the shafts are aligned with the fluid flow, and this torque of rotation is reduced as the shaft approaches a position transverse to the fluid flow. As the shafts pass this transverse position, a torque is developed by the rotating cylinder that rotates the shafts 180/sup 0/ until the formerly downwardly depending cylinder is now upright and the formerly upright cylinder is now downwardly depending on its shaft. With two or more shafts to which cylinders are attached, there is a continuous production of torque about the axis of revolution of the shafts.

  4. Magnus air turbine system

    DOEpatents

    Hanson, Thomas F.

    1982-01-01

    A Magnus effect windmill for generating electrical power is disclosed. A large nacelle-hub mounted pivotally (in Azimuth) atop a support tower carries, in the example disclosed, three elongated barrels arranged in a vertical plane and extending symmetrically radially outwardly from the nacelle. The system provides spin energy to the barrels by internal mechanical coupling in the proper sense to cause, in reaction to an incident wind, a rotational torque of a predetermined sense on the hub. The rotating hub carries a set of power take-off rollers which ride on a stationary circular track in the nacelle. Shafts carry the power, given to the rollers by the wind driven hub, to a central collector or accumulator gear assembly whose output is divided to drive the spin mechanism for the Magnus barrels and the main electric generator. A planetary gear assembly is interposed between the collector gears and the spin mechanism functioning as a differential which is also connected to an auxiliary electric motor whereby power to the spin mechanism may selectively be provided by the motor. Generally, the motor provides initial spin to the barrels for start-up after which the motor is braked and the spin mechanism is driven as though by a fixed ratio coupling from the rotor hub. During high wind or other unusual conditions, the auxiliary motor may be unbraked and excess spin power may be used to operate the motor as a generator of additional electrical output. Interposed between the collector gears of the rotating hub and the main electric generator is a novel variable speed drive-fly wheel system which is driven by the variable speed of the wind driven rotor and which, in turn, drives the main electric generator at constant angular speed. Reference is made to the complete specification for disclosure of other novel aspects of the system such as, for example, the aerodynamic and structural aspects of the novel Magnus barrels as well as novel gearing and other power coupling

  5. Magnus effects on spinning transonic missiles

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Rosenwasser, I.

    1983-01-01

    Magnus forces and moments were measured on a basic-finner model spinning in transonic flow. Spin was induced by canted fins or by full-span or semi-span, outboard and inboard roll controls. Magnus force and moment reversals were caused by Mach number, reduced spin rate, and angle of attack variations. Magnus center of pressure was found to be independent of the angle of attack but varied with the Mach number and model configuration or reduced spin rate.

  6. Magnus approximation in neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Acero, Mario A.; Aguilar-Arevalo, Alexis A.; D'Olivo, J. C.

    2011-04-01

    Oscillations between active and sterile neutrinos remain as an open possibility to explain some anomalous experimental observations. In a four-neutrino (three active plus one sterile) mixing scheme, we use the Magnus expansion of the evolution operator to study the evolution of neutrino flavor amplitudes within the Earth. We apply this formalism to calculate the transition probabilities from active to sterile neutrinos with energies of the order of a few GeV, taking into account the matter effect for a varying terrestrial density.

  7. Magnus force effect in optical manipulation

    SciTech Connect

    Cipparrone, Gabriella; Pagliusi, Pasquale; Hernandez, Raul Josue; Provenzano, Clementina

    2011-07-15

    The effect of the Magnus force in optical micromanipulation has been observed. An ad hoc experiment has been designed based on a one-dimensional optical trap that carries angular momentum. The observed particle dynamics reveals the occurrence of this hydrodynamic force, which is neglected in the common approach. Its measured value is larger than the one predicted by the existing theoretical models for micrometric particles and low Reynolds number, showing that the Magnus force can contribute to unconventional optohydrodynamic trapping and manipulation.

  8. Magnus force effect in optical manipulation

    NASA Astrophysics Data System (ADS)

    Cipparrone, Gabriella; Hernandez, Raul Josue; Pagliusi, Pasquale; Provenzano, Clementina

    2011-07-01

    The effect of the Magnus force in optical micromanipulation has been observed. An ad hoc experiment has been designed based on a one-dimensional optical trap that carries angular momentum. The observed particle dynamics reveals the occurrence of this hydrodynamic force, which is neglected in the common approach. Its measured value is larger than the one predicted by the existing theoretical models for micrometric particles and low Reynolds number, showing that the Magnus force can contribute to unconventional optohydrodynamic trapping and manipulation.

  9. A Pedagogical Approach to the Magnus Expansion

    ERIC Educational Resources Information Center

    Blanes, S.; Casas, F.; Oteo, J. A.; Ros, J.

    2010-01-01

    Time-dependent perturbation theory as a tool to compute approximate solutions of the Schrodinger equation does not preserve unitarity. Here we present, in a simple way, how the "Magnus expansion" (also known as "exponential perturbation theory") provides such unitary approximate solutions. The purpose is to illustrate the importance and…

  10. Lead-Bismuth Activities at the Karlsruhe Lead Laboratory KALLA

    SciTech Connect

    Knebel, Joachim U.; Muller, Georg; Konys, Jurgen

    2002-07-01

    At Forschungszentrum Karlsruhe (FZK) the characteristics of an accelerator-driven subcritical system (ADS) are evaluated, mainly with respect to the potential of transmutation of minor actinides and long-lived fission products, to the feasibility and to safety aspects. All experimental activities, which are related to lead-bismuth as cooling fluid and spallation material, are performed in the Karlsruhe Lead Laboratory KALLA. This article gives an overview on KALLA, which has three stagnant experiments and three loop experiments. The stagnant experiments are concentrating on corrosion mechanisms, surface treatment, oxygen sensor development, and oxygen control system (OCS), the loop experiments are concentrating on thermalhydraulic measurement techniques, ADS-relevant component testing, and corrosion investigations in flowing lead-bismuth. A fourth loop experiment is planned to investigate the integral heat removal from a 4 MW spallation target for normal and decay heat removal conditions. Among others, latest results are presented of: characteristics of oxygen sensors in flowing liquid Pb-Bi, the oxygen control system (OCS) operating on a loop system, an ultrasonic flow meter applied to lead-bismuth at 400 deg. C. In addition, results are given on the improvement of the corrosion resistivity of steels in flowing lead-bismuth, using a special temperature treatment method (electron beam facility GESA) and alloying aluminium in the surface layer. (authors)

  11. New twist to steering. [Magnus effect rotors

    SciTech Connect

    Borg, J.L.

    1980-06-01

    The new vessel steering system is based on The Magnus Effect which is defined in simplified terms; if a vertical cylinder immersed in water is rotated, it produces a force at right angles to the direction of the water flowing past it. The Magnus Effect rotor needs only sufficient torque to overcome bearing and surface friction forces, so that the power requirements are very low. Further energy savings are realized because the rotor can develop maximum turning force or can return to zero in a few seconds. Tests with these cylindrical rudders have been conducted to verify the hydrodynamic theory. This concept is in the preliminary stages of development. Results are expected soon from field testing on an 1800-hp pushboat working four barges on the Warrior and Tombigbee Rivers in Alabama and Mississippi.

  12. Inverse Magnus effect on a rotating sphere

    NASA Astrophysics Data System (ADS)

    Kim, Jooha; Park, Hyungmin; Choi, Haecheon; Yoo, Jung Yul

    2011-11-01

    In this study, we investigate the flow characteristics of rotating spheres in the subcritical Reynolds number (Re) regime by measuring the drag and lift forces on the sphere and the two-dimensional velocity in the wake. The experiment is conducted in a wind tunnel at Re = 0 . 6 ×105 - 2 . 6 ×105 and the spin ratio (ratio of surface velocity to the free-stream velocity) of 0 (no spin) - 0.5. The drag coefficient on a stationary sphere remains nearly constant at around 0.52. However, the magnitude of lift coefficient is nearly zero at Re < 2 . 0 ×105 , but rapidly increases to 0.3 and then remains constant with further increasing Reynolds number. On the other hand, with rotation, the lift coefficient shows negative values, called inverse Magnus effect, depending on the magnitudes of the Reynolds number and spin ratio. The velocity field measured from a particle image velocimetry (PIV) indicates that non-zero lift coefficient on a stationary sphere at Re > 2 . 0 ×105 results from the asymmetry of separation line, whereas the inverse Magnus effect for the rotating sphere results from the differences in the boundary-layer growth and separation along the upper and lower sphere surfaces. Supported by the WCU, Converging Research Center and Priority Research Centers Program, NRF, MEST, Korea.

  13. Magnus force in superfluids and superconductors

    SciTech Connect

    Sonin, E.B. |

    1997-01-01

    The forces on the vortex, transverse to its velocity, are considered. In addition to the superfluid Magnus force from the condensate (superfluid component), there are transverse forces from thermal quasiparticles and external fields violating the Galilean invariance. The forces between quasiparticles and the vortex originate from interference of quasiparticles with trajectories on the left and on the right from the vortex like similar forces for electrons interacting with the thin magnetic-flux tube (the Aharonov-Bohm effect). These forces are derived for phonons from the equations of superfluid hydrodynamics, and for BCS quasiparticles from the Bogolyubov{endash}de Gennes equations. The effect of external fields breaking Galilean invariance is analyzed for vortices in the two-dimensional Josephson junction array. The symmetry analysis of the classical equations for the array shows that the total transverse force on the vortex vanishes. Therefore the Hall effect which is linear in the transverse force is absent also. This means that the Magnus force from the superfluid component {ital exactly} cancels with the transverse force from the external fields. The results of other approaches are also brought together for discussion. {copyright} {ital 1997} {ital The American Physical Society}

  14. Magnus forces and statistics in 2 + 1 dimensions

    SciTech Connect

    Davis, R.L. )

    1990-05-10

    Spinning vortex solutions to the abelian Higgs model, not Nielsen-Olesen solutions, are appropriate to a Ginzburg-Landau description of superconductivity. The main physical distinction is that spinning vortices experience the Magnus force while Nielsen-Olesen vortices do not. In 2 + 1 dimensional superconductivity without a Chern-Simons interaction, the effect of the Magnus force is equivalent to that of a background fictitious magnetic field. Moreover, the phase obtained an interchanging two quasi-particles is always path-dependent. When a Chern-Simons term is added there is an additional localized Magnus flux at the vortex. For point-like vortices, the Chern-Simons interaction can be seen as defining their intrinsic statistics, but in realistic cases of vortices with finite size in strong Magnus fields the quasi-particle statistics are not well-defined.

  15. The Magnus Effect in Theory and in Reality

    NASA Technical Reports Server (NTRS)

    Ahlborn, F

    1930-01-01

    A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.

  16. MAGNUS-3D: Accelerator magnet calculations in 3-dimensions

    NASA Astrophysics Data System (ADS)

    Pissanetzky, S.

    1988-12-01

    MAGNUS-3D is a professional finite element code for nonlinear magnetic engineering. MAGNUS-3D can solve numerically any general problem of linear or nonlinear magnetostatics in three dimensions. The problem is formulated in a domain with Dirichlet, Neumann or periodic boundary conditions, that can contain any combination of conductors of any shape in space, nonlinear magnetic materials with magnetic properties specified by magnetization tables, and nonlinear permanent magnets with any given demagnetization curve. MAGNUS-3D uses the two-scalar-potentials formulation of Magnetostatics and the finite element method, has an automatic 3D mesh generator, and advanced post-processing features that include graphics on a variety of supported devices, tabulation, and calculation of design quantities required in Magnetic Engineering. MAGNUS-3D is a general purpose 3D code, but it has been extensively used for accelerator work and many special features required for accelerator engineering have been incorporated into the code. One of such features is the calculation of field harmonic coefficients averaged in the direction of the beam, so important for the design of magnet ends. Another feature is its ability to calculate line integrals of any field component along the direction of the beam, or plot the field as a function of the z coordinate. MAGNUS-3D has found applications to the design of accelerator magnets and spectrometers, steering magnets, wigglers and undulators for free electron lasers, microtrons and magnets for synchrotron light sources, as well as magnets for NMR and medical applications, recording heads and various magnetic devices. There are three more programs closely associated with MAGNUS-3D. MAGNUS-GKS is the graphical postprocessor for the package; it supports a numer of output devices, including color vector or bit map devices. WIRE is an independent program that can calculate the field produced by any configuration of electric conductors in space, at any

  17. Magnus force in discrete and continuous two-dimensional superfluids

    SciTech Connect

    Gecse, Z.; Khlebnikov, S.

    2005-08-01

    Motion of vortices in two-dimensional superfluids in the classical limit is studied by solving the Gross-Pitaevskii equation numerically on a uniform lattice. We find that, in the presence of a superflow directed along one of the main lattice periods, vortices move with the superflow on fine lattices but perpendicular to it on coarse ones. We interpret this result as a transition from the full Magnus force in a Galilean-invariant limit to vanishing effective Magnus force in a discrete system, in agreement with the existing experiments on vortex motion in Josephson junction arrays.

  18. Anatomy of the Adductor Magnus Origin

    PubMed Central

    Obey, Mitchel R.; Broski, Stephen M.; Spinner, Robert J.; Collins, Mark S.; Krych, Aaron J.

    2016-01-01

    Background: The adductor magnus (AM) has historically been a potential source of confusion in patients with suspected proximal hamstring avulsion injuries. Purpose: To investigate the anatomic characteristics of the AM, including its osseous origin, anatomic dimensions, and relationship to the proximal hamstring tendons. Study Design: Descriptive laboratory study. Methods: Dissection of the AM origin was performed in 11 (8 cadavers) fresh-frozen hip-to-foot cadaveric hemipelvis specimens. The gross anatomy and architecture of the proximal hamstring and AM tendons were studied. After dissecting the hamstring tendons away from their origin, the dimension, shape, and orientation of the tendon footprints on the ischial tuberosity were determined. Results: The AM was identified in all cadaveric specimens. The mean tendon thickness (anterior to posterior [AP]) was 5.7 ± 2.9 mm. The mean tendon width (medial to lateral [ML]) was 7.1 ± 2.2 mm. The mean tendon length was 13.1 ± 8.7 cm. The mean footprint height (AP dimension) was 12.1 ± 2.9 mm, and mean footprint width (ML dimension) was 17.3 ± 7.1 mm. The mean distance between the AM footprint and the most medial aspect of the conjoint tendon footprint was 8.5 ± 4.2 mm. Tendon measurements demonstrated a considerable degree of both intra- and interspecimen variability. Conclusion: The AM tendon is consistently present just medial to the conjoint tendon at the ischial tuberosity, representing the lateral-most portion of the AM muscle. This study found wide variation in the dimensional characteristics of the AM tendon between specimens. Its shape and location can mimic the appearance of an intact hamstring (conjoint or semimembranosus) tendon intraoperatively or on diagnostic imaging, potentially misleading surgeons and radiologists. Therefore, detailed knowledge of the AM tendon anatomy, footprint anatomy, and its relationship to the hamstring muscle complex is paramount when planning surgical approach and technique

  19. The "Magnus effect" - the principle of the Flettner rotor

    NASA Technical Reports Server (NTRS)

    Betz, A

    1925-01-01

    The phenomenon of the Magnus effect consists in the fact that a revolving body moving relatively to the surrounding fluid (air) is subjected not only to drag (i.e., a force acting in a direction opposite to that of the direction of motion), but also to a lift.

  20. Magnus Strandqvist: 50th anniversary of his doctoral thesis.

    PubMed

    Kajanti, M J

    1994-01-01

    This article is dedicated to Magnus Strandqvist's famous doctoral thesis "Studien über die kumulative Wirkung der Röntgenstrahlen bei Fraktionierung. Erfahrungen aus dem Radiumhemmet an 280 Haut- und Lippenkarzinomen" published in Acta Radiologica in 1944. After a short biography of Strandqvist some central points of his work and their influence on future development of modern radiotherapy are presented. PMID:7993639

  1. A review of the Magnus effect in aeronautics

    NASA Astrophysics Data System (ADS)

    Seifert, Jost

    2012-11-01

    The Magnus effect is well-known for its influence on the flight path of a spinning ball. Besides ball games, the method of producing a lift force by spinning a body of revolution in cross-flow was not used in any kind of commercial application until the year 1924, when Anton Flettner invented and built the first rotor ship Buckau. This sailboat extracted its propulsive force from the airflow around two large rotating cylinders. It attracted attention wherever it was presented to the public and inspired scientists and engineers to use a rotating cylinder as a lifting device for aircraft. This article reviews the application of Magnus effect devices and concepts in aeronautics that have been investigated by various researchers and concludes with discussions on future challenges in their application.

  2. Numerical simulation of negative Magnus force on a rotating sphere

    NASA Astrophysics Data System (ADS)

    Muto, Masaya; Tsubokura, Makoto; Oshima, Nobuyuki

    2010-11-01

    Flow characteristics and fluid force on a sphere rotating along with axis perpendicular to mean air flow were investigated using Large Eddy Simulation at two different Reynolds numbers of 10,000 and 200,000. As a result of simulation, opposite flow characteristics around the sphere and displacement of the separation point were visualized depending on the Reynolds number even though the sphere rotates at the same rotation speed according to the Reynolds number. When Reynolds number is 10,000, flow characteristics agree with the flow field explained in the Magnus effect. However sphere rotates at the same rotation speed while increasing Reynolds number to 200,000, separation point moves in opposite direction and wake appears in the different direction. The reason of the negative Magnus force was discussed in terms of the boundary layer transition on the surface.

  3. Magnus expansion and in-medium similarity renormalization group

    NASA Astrophysics Data System (ADS)

    Morris, T. D.; Parzuchowski, N. M.; Bogner, S. K.

    2015-09-01

    We present an improved variant of the in-medium similarity renormalization group (IM-SRG) based on the Magnus expansion. In the new formulation, one solves flow equations for the anti-Hermitian operator that, upon exponentiation, yields the unitary transformation of the IM-SRG. The resulting flow equations can be solved using a first-order Euler method without any loss of accuracy, resulting in substantial memory savings and modest computational speedups. Since one obtains the unitary transformation directly, the transformation of additional operators beyond the Hamiltonian can be accomplished with little additional cost, in sharp contrast to the standard formulation of the IM-SRG. Ground state calculations of the homogeneous electron gas (HEG) and 16O nucleus are used as test beds to illustrate the efficacy of the Magnus expansion.

  4. Magnus effects at high angles of attack and critical Reynolds numbers

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Ringel, M.

    1983-01-01

    The Magnus force and moment experienced by a yawed, spinning cylinder were studied experimentally in low speed and subsonic flows at high angles of attack and critical Reynolds numbers. Flow-field visualization aided in describing a flow model that divides the Magnus phenomenon into a subcritical region, where reverse Magnus loads are experienced, and a supercritical region where these loads are not encountered. The roles of the spin rate, angle of attack, and crossflow Reynolds number in determining the boundaries of the subcritical region and the variations of the Magnus loads were studied.

  5. A new 5-alkylresorcinol glucoside derivative from Cybianthus magnus.

    PubMed

    Cabanillas, B; Vásquez-Ocmín, P; Zebiri, I; Rengifo, E; Sauvain, M; Le, H L; Vaisberg, A; Voutquenne-Nazabadioko, L; Haddad, M

    2016-01-01

    One new 5-alkylresorcinol glucoside (1) was isolated from leaves of Cybianthus magnus, along with 12 known compounds (2-13), isolated from four plants belonging to Myrsinaceae family. Their structures were determined on the basis of spectroscopic analysis and by comparison of their spectral data with those reported in the literature. Among the tested molecules, only compound 2 displayed a strong cytotoxic activity with IC50 values ranging between 22 and 100 μM for all cell lines tested. One new 5-alkylresorcinol glucoside (1) was isolated from leaves of Cybianthus magnus, along with 12 known compounds, isolated from four plants belonging to Myrsinaceae family (2, 3 isolated from C. magnus; 4-7, 10 and 11 isolated from Myrsine latifolia; 4, 8 and 9 isolated from Myrsine sessiflora; 6, 7, 10, 12 and 13 isolated from Myrsine congesta). Their structures were determined on the basis of spectroscopic analysis and by comparison of their spectral data with those reported in the literature. So far, only nine 5-alkylresorcinol glucosides were isolated from leaves of Grevillea robusta. Since resorcinols are known to exhibit strong cytotoxic activity, compounds 1 and 2 were tested against cell lines 3T3, H460, DU145 and MCF-7 for cytotoxicity in vitro and compounds 3-13 were tested for their antileishmanial activity. Compound 2 displayed a strong cytotoxic activity with IC50 values ranging between 22 and 100 μM for all tested cell lines. Compounds 3-13 were not active against Leishmania amazonensis amastigotes. PMID:26181307

  6. [Magnus Hirschfeld and monism: mutual fertilization or exchange of errors?].

    PubMed

    Mildenberger, Florian

    2007-01-01

    When Ernst Haeckel was buried in Jena on February 12th, 1919, some of his supporters and followers were allowed to make speeches. One of them was the sexologist Magnus Hirschfeld, although he had entered the German-Monist-Club only six years after its foundation in 1906. He became one of the most important monists, because he worked in the fields of sexuality and eugenics, and was head of discourse for many years. But he imported some ideas of his colleagues for his own studies, especially the neolamarckism. The failure of this theory had decisive consequences for monism and sexology, as well. PMID:18354891

  7. STS-112 M.S. Magnus suits up before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 Mission Specialist Sandra Magnus finishes suiting up before launch. STS-112 is the 15th assembly flight to the International Space Station, carrying the S1 Integrated Truss Structure and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss to the Station. Launch is scheduled for 3:46 p.m. EDT from Launch Pad 39B.

  8. Vacancy-rearrangement theory in the first Magnus approximation

    SciTech Connect

    Becker, R.L.

    1984-01-01

    In the present paper we employ the first Magnus approximation (M1A), a unitarized Born approximation, in semiclassical collision theory. We have found previously that the M1A gives a substantial improvement over the first Born approximation (B1A) and can give a good approximation to a full coupled channels calculation of the mean L-shell vacancy probability per electron, p/sub L/, when the L-vacancies are accompanied by a K-shell vacancy (p/sub L/ is obtained experimentally from measurements of K/sub ..cap alpha../-satellite intensities). For sufficiently strong projectile-electron interactions (sufficiently large Z/sub p/ or small v) the M1A ceases to reproduce the coupled channels results, but it is accurate over a much wider range of Z/sub p/ and v than the B1A. 27 references.

  9. Role of transverse-momentum currents in the optical Magnus effect in free space

    NASA Astrophysics Data System (ADS)

    Luo, Hailu; Wen, Shuangchun; Shu, Weixing; Fan, Dianyuan

    2010-05-01

    We establish a general vector field model to describe the role of transverse-momentum currents in the optical Magnus effect in free space. As an analogy of the mechanical Magnus effect, the circularly polarized wave packet in our model acts as the rotating ball, and its rotation direction depends on the polarization state. Based on this model, we demonstrate the existence of an optical polarization-dependent Magnus effect which is significantly different from the conventional optical Magnus effect in that light-matter interaction is not required. Further, we reveal the relation between transverse-momentum currents and the optical Magnus effect, and find that such a polarization-dependent rotation is unavoidable when the wave packet possesses transverse-momentum currents. The physics underlying this intriguing effect is the combined contributions of transverse spin and orbital currents. We predict that this effect may be observed experimentally even in the propagation direction. These findings provide further evidence for the optical Magnus effect in free space and can be extrapolated to other physical systems.

  10. Role of transverse-momentum currents in the optical Magnus effect in free space

    SciTech Connect

    Luo Hailu; Wen Shuangchun; Shu Weixing; Fan Dianyuan

    2010-05-15

    We establish a general vector field model to describe the role of transverse-momentum currents in the optical Magnus effect in free space. As an analogy of the mechanical Magnus effect, the circularly polarized wave packet in our model acts as the rotating ball, and its rotation direction depends on the polarization state. Based on this model, we demonstrate the existence of an optical polarization-dependent Magnus effect which is significantly different from the conventional optical Magnus effect in that light-matter interaction is not required. Further, we reveal the relation between transverse-momentum currents and the optical Magnus effect, and find that such a polarization-dependent rotation is unavoidable when the wave packet possesses transverse-momentum currents. The physics underlying this intriguing effect is the combined contributions of transverse spin and orbital currents. We predict that this effect may be observed experimentally even in the propagation direction. These findings provide further evidence for the optical Magnus effect in free space and can be extrapolated to other physical systems.

  11. Origin of the Magnus force on a vortex in fermion superfluids and superconductors

    SciTech Connect

    Simanek, E.

    1995-10-01

    Starting from the time-dependent version of the Feynman-Hellmann theorem, the Magnus force acting on a vortex in fermion superfluid is expressed via the adiabatic curvature over the space of vortex positions. With use of the Bogoliubov--de Gennes approximation, the Magnus force in a homogeneous superfluid at {ital T}=0 is shown to originate from virtual transitions between the lowest quasiparticle core bound states. Nonadiabatic corrections to the curvature are obtained to second order in vortex velocity. The adiabatic approximation is shown to break down at a critical velocity equal to the vortex velocity in the first Landau level. The effect of elastic scattering on the Magnus force is discussed in terms of the relaxation-time approximation. It is suggested that this approximation is appropriate only for a large-scale vortex motion. In this case, the effective Magnus force is drastically reduced when the elastic-scattering rate exceeds the core excitation frequency. We conjecture that quantum vortex tunneling is governed by a local Magnus force obtained from the Berry phase approach.

  12. Magnus-induced ratchet effects for skyrmions interacting with asymmetric substrates

    NASA Astrophysics Data System (ADS)

    Reichhardt, C.; Ray, D.; Olson Reichhardt, C. J.

    2015-07-01

    We show using numerical simulations that pronounced ratchet effects can occur for ac driven skyrmions moving over asymmetric quasi-one-dimensional substrates. We find a new type of ratchet effect called a Magnus-induced transverse ratchet that arises when the ac driving force is applied perpendicular rather than parallel to the asymmetry direction of the substrate. This transverse ratchet effect only occurs when the Magnus term is finite, and the threshold ac amplitude needed to induce it decreases as the Magnus term becomes more prominent. Ratcheting skyrmions follow ordered orbits in which the net displacement parallel to the substrate asymmetry direction is quantized. Skyrmion ratchets represent a new ac current-based method for controlling skyrmion positions and motion for spintronic applications.

  13. Magnus force and the inertial properties of magnetic vortices in weak ferromagnets

    NASA Astrophysics Data System (ADS)

    Zvezdin, A. K.; Zvezdin, K. A.

    2010-08-01

    The Magnus force (gyroscopic force) acting on magnetic vortices (Bloch lines) within domain boundaries in weak ferromagnets is discussed. A general formula is derived for the Magnus force in weak ferromagnets. The Magnus force is found to be nonzero for most types of domain boundaries and is determined by the average sublattice magnetization and the constants for the Dzyaloshinsky interaction and the exchange interaction between sublattices. Generalized expressions are obtained for the effective Lagrange and Rayleigh functions in weak ferromagnets taking their vortex structure into account. The question of the vortex mass, which has been found to be on the order of m*˜10-14g/cm in YFeO3, is discussed. The dynamic flexure of domain boundaries when moving vortices are present is analyzed. A formula is derived for the magnetic field dependence of the velocity of a vortex in a motionless domain boundary.

  14. Computations of the Magnus effect for slender bodies in supersonic flow

    NASA Technical Reports Server (NTRS)

    Sturek, W. B.; Schiff, L. B.

    1980-01-01

    A recently reported Parabolized Navier-Stokes code has been employed to compute the supersonic flow field about spinning cone, ogive-cylinder, and boattailed bodies of revolution at moderate incidence. The computations were performed for flow conditions where extensive measurements for wall pressure, boundary layer velocity profiles and Magnus force had been obtained. Comparisons between the computational results and experiment indicate excellent agreement for angles of attack up to six degrees. The comparisons for Magnus effects show that the code accurately predicts the effects of body shape and Mach number for the selected models for Mach numbers in the range of 2-4.

  15. Effect of Magnus force on the scale deposition in geothermal systems

    SciTech Connect

    Michaelides, E.E.

    1981-12-01

    The Magnus lift force acts on solid particles present in vertical flows. The action of this force facilitates the mechanism of deposition. In upward flow (production wells), the turbulent fluctuations are necessary for the mechanism of deposition since they bring the particle into the laminar sublayer. In the downward flow, the Magnus force consistently acts toward the wall and turbulent fluctuations are no longer necessary for the mechanism of deposition. If the particle reaches the laminar sublayer, the forces acting on it will keep it near the wall until it is deposited. 10 refs.

  16. Anisotropic Magnus Force in Type-II Superconductors with Planar Defects

    NASA Astrophysics Data System (ADS)

    Monroy, Ricardo Vega; Gomez, Eliceo Cortés

    2015-02-01

    The effect of planar defects on the Magnus force in type-II superconductors is studied. It is shown that the deformation of the vortex due to the presence of a planar defect leads to a local decrease in the mean free path of electrons in the vortex. This effect reduces the effective Magnus coefficient in normal direction to the planar defect, leading to an anisotropic regime of the Hall effect. The presented developments here can qualitatively explain experimental observations of the anisotropic Hall effect in high- T c superconductors in the mixed state.

  17. Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

    SciTech Connect

    Takegoshi, K. Miyazawa, Norihiro; Sharma, Kshama; Madhu, P. K.

    2015-04-07

    We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

  18. Response to Yiannis Miralis, "Manos Hadjidakis: The Story of an Anarchic Youth and a "Magnus Eroticus"

    ERIC Educational Resources Information Center

    Serghi, Lenia

    2004-01-01

    Manos Hadjidakis and his work are like his song, "O Mythos," for they take you from reality to fantasy and bring you back again. In Magnus Eroticus, the combination of lyrics and music is at the highest level of sensibility and the musical style of each song is superb. Music follows the verse to express its deepest meaning while maintaining its…

  19. Negative Magnus Effect on a Rotating Sphere at around the Critical Reynolds Number

    NASA Astrophysics Data System (ADS)

    Muto, Masaya; Watanabe, Hiroaki; Tsubokura, Makoto; Oshima, Nobuyuki

    2011-12-01

    Negative Magnus lift acting on a sphere rotating about the axis perpendicular to an incoming flow is investigated using large-eddy simulation at three Reynolds numbers of 1.0× 104, 2.0 × 105, and 1.14 × 106. The numerical methods adopted are first validated on a non-rotating sphere and the spatial resolution around the sphere is determined so as to reproduce the laminar separation, reattachment, and turbulent transition of the boundary layer observed at around the critical Reynolds number. In the rotating sphere, positive or negative Magnus effect is observed depending on the Reynolds number and the rotating speed imposed. At the Reynolds number in the subcritical or supercritical region, the direction of the lift force follows the Magnus effect to be independent of the rotational speed tested here. In contrast, negative lift is observed at the Reynolds number at the critical region when particular rotating speeds are imposed. The negative Magnus effect is discussed in the context of the suppression or promotion of boundary layer transition around the separation point.

  20. Negative Magnus lift on a rotating sphere at around the critical Reynolds number

    NASA Astrophysics Data System (ADS)

    Muto, Masaya; Tsubokura, Makoto; Oshima, Nobuyuki

    2012-01-01

    Negative Magnus lift acting on a sphere rotating about the axis perpendicular to an incoming flow was investigated using large-eddy simulation at three Reynolds numbers of 1.0 × 104, 2.0 × 105, and 1.14 × 106. The numerical methods used were first validated on a non-rotating sphere, and the spatial resolution around the sphere was determined so as to reproduce the laminar separation, reattachment, and turbulent transition of the boundary layer observed in the vicinity of the critical Reynolds number. The rotating sphere exhibited a positive or negative Magnus effect depending on the Reynolds number and the imposed rotating speed. At Reynolds numbers in the subcritical or supercritical regimes, the direction of the Magnus lift force was independent of the rotational speed. In contrast, the lift force was negative in the critical regime when particular rotating speeds were imposed. This negative Magnus effect was investigated in the context of suppression or promotion of boundary layer transition around the separation point.

  1. Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

    NASA Astrophysics Data System (ADS)

    Takegoshi, K.; Miyazawa, Norihiro; Sharma, Kshama; Madhu, P. K.

    2015-04-01

    We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

  2. Synodic Period for 2454 Olaus Magnus from Frank T. Etscorn Observatory

    NASA Astrophysics Data System (ADS)

    Vargas, Angelica

    2013-04-01

    The main-belt asteroid 2454 Olaus Magnus was observed between 2012 October 6 and November 6 at Etscorn Observatory. Analysis found a synodic period of 3.804 ± 0.002 h and amplitude of 0.39 ± 0.10 mag.

  3. Simulation of Effects of the Saffman Force and the Magnus Force on Sand Saltation in Turbulent Flow

    SciTech Connect

    Zheng, Zhongquan C.; Zou, Xueyong; Yang, Xiaofan; Cheng, Hong

    2011-12-11

    The effects of both the Saffman force and Magnus force on sand saltation are investigated. Turbulent flows in a channel and over a barchans dune are considered with sand particles injected into the flow. The results show that both of the forces increase the height and skipping distance of sand saltation, with the Magnus force giving more significant effect on the height. These forces can also increase the sand settling at the lee side of the barchans dune.

  4. Distribution, chemistry, isotopic composition and origin of diagenetic carbonates: Magnus Sandstone, North Sea

    SciTech Connect

    Macaulay, C.I.; Haszeldine, R.S. ); Fallick, A.E. )

    1993-01-01

    Diagenetic ferroan carbonates grew in the Upper Jurassic reservoir sandstones of the Magnus oilfield in porewaters which differed in composition across the field. These porewaters remained compositionally different and stratified for at least 35 M.y. Variations in carbonate chemistry across the field are attributable to these porewater variations, which resulted from displacement of marine depositional water from the crest of the field by meteoric water during late Cimmerian subaerial exposure. Original depositional facies and detrital mineralogy strongly influenced diagenetic carbonate distribution. The objective of this paper is twofold: (1) to describe the occurrence of burial diagenetic magnesian siderite and ankerite from the Magnus Sandstone, and (2) to show that variations in the elemental and isotopic geochemistry of siderite and ankerite relate to long-lived variations in the composition of the porewaters in the sandstone during diagenesis.

  5. The Magnus expansion and the in-medium similarity renormalization group

    SciTech Connect

    Morris, T. D.; Bogner, S. K.

    2014-10-15

    We present a variant of the in-medium similarity renormalization group(IMSRG) based on the Magnus expansion. In this new variant, the unitary transformation of the IMSRG is constructed explicitly, which allows for the transformation of observables quickly and easily. Additionally, the stiffness of equations encountered by the traditional solution of the IMSRG can be alleviated greatly. We present results and comparisons for the 3d electron gas.

  6. The Magnus-Rademaker Scientific Film Collection: Ethical Issues on Animal Experimentation (1908-1940).

    PubMed

    Koehler, Peter J; Lameris, Bregt

    2016-01-01

    The Magnus-Rademaker scientific film collection (1908-1940) deals with the physiology of body posture by the equilibrium of reflex musculature contractions for which experimental studies were carried out with animals (e.g., labyrinthectomies, cerebellectomies, and brain stem sections) as well as observations done on patients. The films were made for demonstrations at congresses as well as educational objectives and film stills were published in their books. The purpose of the present study is to position these films and their makers within the contemporary discourse on ethical issues and animal rights in the Netherlands and the earlier international debates. Following an introduction on animal rights and antivivisection movements, we describe what Magnus and Rademaker thought about these issues. Their publications did not provide much information in this respect, probably reflecting their adherence to implicit ethical codes that did not need explicit mentioning in publications. Newspaper articles, however, revealed interesting information. Unnecessary suffering of an animal never found mercy in Magnus' opinion. The use of cinematography was expanded to the reduction of animal experimentation in student education, at least in the case of Rademaker, who in the 1930s was involved in a governmental committee for the regulation of vivisection and cooperated with the antivivisection movement. This resulted not only in a propaganda film for the movement but also in films that demonstrate physiological experiments for students with the purpose to avert repetition and to improve the teaching of experiments. We were able to identify the pertinent films in the Magnus-Rademaker film collection. The production of vivisection films with this purpose appears to have been common, as is shown in news messages in European medical journals of the period. PMID:26684427

  7. Curveballs in protoplanetary discs - the effect of the Magnus force on planet formation

    NASA Astrophysics Data System (ADS)

    Forbes, John C.

    2015-10-01

    Spinning planetesimals in a gaseous protoplanetary disc may experience a hydrodynamical force perpendicular to their relative velocities. We examine the effect this force has on the dynamics of these objects using analytical arguments based on a simple laminar disc model and numerical integrations of the equations of motion for individual grains. We focus in particular on metre-sized boulders traditionally expected to spiral in to the central star in as little as 100 years from 1 au We find that there are plausible scenarios in which this force extends the lifetime of these solids in the disc by a factor of several. More importantly the velocities induced by the Magnus force can prevent the formation of planetesimals via gravitational instability in the inner disc if the size of the dust particles is larger than of the order of 10 cm. We find that the fastest growing linear modes of the streaming instability may still grow despite the diffusive effect of the Magnus force, but it remains to be seen how the Magnus force will alter the non-linear evolution of these instabilities.

  8. The complete mitochondrial genome of the sexual oribatid mite Steganacarus magnus: genome rearrangements and loss of tRNAs

    PubMed Central

    Domes, Katja; Maraun, Mark; Scheu, Stefan; Cameron, Stephen L

    2008-01-01

    Background Complete mitochondrial (mt) genomes and the gene rearrangements therein are increasingly used as molecular markers for investigating phylogenetic relationships, especially for elucidating deep splits. Contributing to the complete mt genomes of arthropods, especially Arachnida, available so far, we provide the first complete mt genome of a sarcoptiform mite species, the sexually reproducing oribatid mite Steganacarus magnus (Acari, Oribatida) which was determined by sequencing of long PCR products. Results The mt genome of S. magnus lacks 16 tRNAs, only those for leucine, histidine, proline, tryptophan, glutamine and serine are present. Within those tRNAs only tRNA-His and tRNA-Pro have kept their original position, the others are translocated. Furthermore, the mt genome of S. magnus consists of 13,818 bp and it is composed of 13 protein-coding genes and two genes for the ribosomal RNA subunits that are typically found in metazoan mt genomes. The gene order in S. magnus differs from the hypothetical ancestral chelicerate arrangement as conserved in Limulus polyphemus: instead of nad1-rrnL-rrnS-LNR-nad2 (tRNAs excluded) S. magnus is nad2-rrnL-nad1-rrnS-LNR. Phylogenetic analyses of a concatenated amino acid dataset of all mt protein-coding genes of 28 arthropod species suggest a sister-group relationship of sarcoptiform and prostigmatid mites (S. magnus and Leptotrombidium). Conclusion The mt gene arrangement of S. magnus differs from the hypothetical ground plan of arthropods and from that of other mites further contributing to the variety of mt gene arrangements found in Arachnida. The unexpected lack of tRNAs is enigmatic, probably showing that the loss of mt genes is an ongoing evolutionary process. For solving phylogenetic relationships of oribatid mite lineages and their position within Acari further complete mt genomes are needed. PMID:18992147

  9. Neurocinematography in Pre-World War II Netherlands: The Magnus-Rademaker Collection.

    PubMed

    Koehler, Peter J; Lameris, Bregt; Hielscher, Eva

    2016-01-01

    Historical films made by neuroscientists have shown up in several countries during past years. Although originally supposed to have been lost, we recently found a collection of films produced between 1909 and 1940 by Rudolf Magnus (1873-1927), professor of pharmacology (Utrecht) and his student Gysbertus Rademaker (1887-1957), professor of physiology (1928, succeeding Willem Einthoven) and neurology (1945, both in Leiden). Both collections deal with the physiology of body posture by the equilibrium of reflex musculature contractions for which experimental studies were done with animals (labyrinthectomies, cerebellectomies, and brainstem sections) and observations on patients. The films demonstrate the results of these studies. Moreover, there are films with babies showing tonic neck reflexes and moving images capturing adults with cerebellar symptoms following cerebellectomies for tumors and several other conditions. Magnus' studies resulted in his well-known Körperstellung (1924, "Body Posture") and Rademaker's research in his Das Stehen (1931, "Standing"). The films probably had an educative and scientific purpose. Magnus demonstrated his films at congresses, including the Eighth International Congress of Physiologists (Vienna, 1910) and Rademaker screened his moving images at meetings of the Amsterdam Neurologists Society (at several occasions as reflected in the Winkler-Monakow correspondence and the Nederlands Tijdschrift voor Geneeskunde). Next to these purposes, the films were used to analyze movement and a series of images from the films were published in articles and books. The films are important historical sources that provide a portrait of the pre-World War II era in neuroscience, partly answering questions on how physicians dealt with patients and researchers with their laboratory animals. Moreover, the films confirm that cinematography was an important scientific tool in neuroscience research. PMID:26684426

  10. Floquet-Magnus expansion for general N-coupled spins systems in magic-angle spinning nuclear magnetic resonance spectra

    NASA Astrophysics Data System (ADS)

    Mananga, Eugene Stephane; Charpentier, Thibault

    2015-04-01

    In this paper we present a theoretical perturbative approach for describing the NMR spectrum of strongly dipolar-coupled spin systems under fast magic-angle spinning. Our treatment is based on two approaches: the Floquet approach and the Floquet-Magnus expansion. The Floquet approach is well known in the NMR community as a perturbative approach to get analytical approximations. Numerical procedures are based on step-by-step numerical integration of the corresponding differential equations. The Floquet-Magnus expansion is a perturbative approach of the Floquet theory. Furthermore, we address the " γ -encoding" effect using the Floquet-Magnus expansion approach. We show that the average over " γ " angle can be performed for any Hamiltonian with γ symmetry.

  11. 3-D magnetic field calculations for wiggglers using MAGNUS-3D

    SciTech Connect

    Pissanetzky, S.; Tompkins, P.

    1988-01-01

    The recent but steady trend toward increased magnetic and geometric complexity in the design of wigglers and undulators, of which tapered wigglers, hybrid structures, laced electromagnetic wigglers, magnetic cladding, twisters and magic structures are examples, has caused a need for reliable 3-D computer models and a better understanding of the behavior of magnetic systems in three dimensions. The capabilities of the MAGNUS-3D Group of Programs are ideally suited to solve this class of problems and provide insight into 3-D effects. MAGNUS-3D can solve any problem of Magnetostatics involving permanent magnets, linear or nonlinear ferromagnetic materials and electric conductors of any shape in space. The magnetic properties of permanent magnets are described by the complete nonlinear demagnetization curve as provided by the manufacturer, or, at the user's choice, by a simpler approximation involving the coercive force, the residual induction and the direction of magnetization. The ferromagnetic materials are described by a magnetization table and an accurate interpolation relation. An internal library with properties of common industrial steels is available. The conductors are independent of the mesh and are described in terms of conductor elements from an internal library.

  12. The tripartite origins of the tonic neck reflex: Gesell, Gerstmann, and Magnus.

    PubMed

    Shevell, Michael

    2009-03-01

    The standard neurologic examination of the newborn and infant includes the elicitation of the tonic neck reflex. Normally present, its persistence is suggestive of neurologic dysfunction and a prognostic marker highly suggestive of an adverse outcome. Working in different fields, with different approaches and largely independently, three leaders of early 20th century neurosciences (Rudolf Magnus, Josef Gerstmann, and Arnold Gesell) elaborated different aspects of this primitive reflex. Magnus provided the first description in an animal model utilizing a meticulously prepared decerebrate cat correctly identifying the reflex's reliance on proprioceptors in the neck and processing in the upper cervical segment. Gerstmann first described its occurrence in the setting of neurologic disease, providing a meticulous written description in an early description of the index case of what would later be eponymously designated Gerstmann-Straussler-Scheinker syndrome. Gesell initially described the reflex's fundamental occurrence in normal young infants, highlighting its adaptive role in early development and its persistence as a hallmark of neurologic pathology. PMID:19255413

  13. Nitric oxide in the nucleus raphe magnus modulates cutaneous blood flow in rats during hypothermia

    PubMed Central

    Arami, Masoumeh Kourosh; zade, Javad Mirnajafi; Komaki, Alireza; Amiri, Mahmood; Mehrpooya, Sara; Jahanshahi, Ali; Jamei, Behnam

    2015-01-01

    Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of hypothermia. Results: Intra-NRM injection of SNP (exogenous NO donor, 0.1- 0.2 μl, 0.2 nM) increased the blood flow. Similarly, unilateral microinjection of glutamate (0.1- 0.2 μl, 2.3 nM) into the nucleus increased the blood flow. This effect of L-glutamate was reduced by prior intra NRM administration of NO synthase inhibitor NG-methyl-L-arginine or NG-nitro-L-arginine methyl ester (L-NAME, 0.1 µl, 100 nM). Conclusion: It is concluded that NO modulates the thermoregulatory response of NRM to hypothermia and may interact with excitatory amino acids in central skin blood flow regulation. PMID:26730333

  14. The Results of Adductor Magnus Tenodesis in Adolescents with Recurrent Patellar Dislocation

    PubMed Central

    Malecki, Krzysztof; Fabis, Jaroslaw; Flont, Pawel; Niedzielski, Kryspin Ryszard

    2015-01-01

    Recurrent dislocation of the patella is a common orthopaedic problem which occurs in about 44% of cases after first-time dislocation. In most cases of first-time patellar dislocation, the medial patellofemoral ligament (MPFL) becomes damaged. Between 2010 and 2012, 33 children and adolescents (39 knees) with recurrent patellar dislocation were treated with MPFL reconstruction using the adductor magnus tendon. The aim of our study is to assess the effectiveness of this surgical procedure. The outcomes were evaluated functionally (Lysholm knee scale, the Kujala Anterior Knee Pain Scale, and isokinetic examination) and radiographically (Caton index, sulcus angle, congruence angle, and patellofemoral angle). Four patients demonstrated redislocation with MPFL graft failure, despite the fact that patellar tracking was found to be normal before the injury, and the patients had not reported any symptoms. Statistically significant improvements in Lysholm and Kujala scales, in patellofemoral and congruence angle, were seen (P < 0.001). A statistically significant improvement in the peak torque of the quadriceps muscle and flexor was observed for 60°/sec and 180°/sec angular velocities (P = 0.01). Our results confirm the efficacy of MPFL reconstruction using the adductor magnus tendon in children and adolescents with recurrent patellar dislocation. PMID:25785271

  15. Numerical investigation of the effect of sphere dimples on the drag crisis and the Magnus effect

    NASA Astrophysics Data System (ADS)

    Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

    2015-11-01

    The present study investigates the flow over a golf ball and a smooth sphere around the critical Reynolds numbers under both stationary and self-spinning conditions by conducting Large-eddy simulations (LES) based on high resolution unstructured grids. For the stationary cases, the present calculation results validate the promotion of the drag crisis at a relatively lower Reynolds number due to the golf ball dimples. It also shows that the golf ball dimples have a limited effect on the time-dependent lateral force development in the subcritical regime, whereas the dimples are beneficial in suppressing the lateral force oscillations in the supercritical regimes. With spin parameter Γ = 0.1, the drag coefficients for the spinning smooth sphere increase slightly in all Reynolds number regimes when compared to the stationary cases, whereas for the spinning golf ball, the drag force decreases in the critical regime and increases in the supercritical regime. For both spinning models, the inverse Magnus effect was reproduced in the critical regime, whereas in the supercritical regime the ordinary Magnus force was generated. Relatively weaker lift forces were also observed in the cases of the spinning golf balls when compared to the spinning smooth spheres.

  16. Textual alchemy: the transformation of pseudo-Albertus Magnus's Semita recta into the Mirror of Lights.

    PubMed

    Grund, Peter

    2009-11-01

    This article explores the strategies of and the reasons behind the reworking of pseudo-Albertus Magnus's Semita recta into the Mirror of Lights. I argue that the redactor sought to provide a more comprehensive defence of the legitimacy of alchemy than found in the Semita recta. In the process of doing so, he reshaped the original text so as to present three units that addressed different parts of the alchemical opus: first, theory and justification of alchemy; second, basic information on substances and procedures; and, third, practice. The redactor employed sophisticated textual tools identical to those seen in scholastic texts. These strategies, I argue, constitute part of the redactor's attempt to bring authority and credibility to his project and to alchemy in general. Certainly, much more attention needs to be paid to these experiments of textual alchemy in order to understand the practice of alchemy in the late medieval period. PMID:20506702

  17. STS-112 M.S. Magnus in white room before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - -- In the White Room at Launch Pad 39B, STS-112 Mission Specialist Sandra H. Magnus, Ph.D., receives assistance with her spacesuit before boarding Space Shuttle Atlantis. Liftoff is schedued for 3:46 p.m. EDT. Along with a crew of six, Atlantis will carry the S1 Integrated Truss Structure and the Crew and Equipment Translation Aid (CETA) Cart A to the International Space Station (ISS). The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss.

  18. Magnus Hirschfeld, his biographies and the possibilities and boundaries of "biography" as "doing history.".

    PubMed

    Brennan, Toni; Hegarty, Peter

    2009-12-01

    This article considers the two major biographies of sexologist Magnus Hirschfeld, MD (1868-1935), an early campaigner for "gay rights" avant la lettre. Like him, his first biographer Charlotte Wolff (1897-1986) was a Jewish doctor who lived and worked in Weimar Republic Berlin and fled Germany when the Nazi regime came to power. When researching Hirschfeld's biography (published in English in 1986) Wolff met a librarian and gay activist, Manfred Herzer, who would eventually be a cofounder of the Gay Museum in Berlin and publish (in German, in 1992) the other major Hirschfeld biography currently available. Using, inter alia, the correspondence between Wolff and Herzer, the article aims to explore and interrogate the boundaries and possibilities of "biography" as a form of "doing history." PMID:20422759

  19. The adductor part of the adductor magnus is innervated by both obturator and sciatic nerves.

    PubMed

    Takizawa, Megumi; Suzuki, Daisuke; Ito, Hajime; Fujimiya, Mineko; Uchiyama, Eiichi

    2014-07-01

    The hip adductor group, innervated predominantly by the obturator nerve, occupies a large volume of the lower limb. However, case reports of patients with obturator nerve palsy or denervation have described no more than minimal gait disturbance. Those facts are surprising, given the architectural characteristics of the hip adductors. Our aim was to investigate which regions of the adductor magnus are innervated by the obturator nerve and by which sciatic nerve and to consider the clinical implications. Twenty-one lower limbs were examined from 21 formalin-fixed cadavers, 18 males and 3 females. The adductor magnus was dissected and was divided into four parts (AM1-AM4) based on the locations of the perforating arteries and the adductor hiatus. AM1 was supplied solely by the obturator nerve. AM2, AM3, and AM4 received innervation from both the posterior branch of the obturator nerve and the tibial nerve portion of the sciatic nerve in 2 (9.5%), 20 (95.2%), and 6 (28.6%) of the cadavers, respectively. The double innervation in more than 90% of the AM3s is especially noteworthy. Generally, AM1-AM3 corresponds to the adductor part, traditionally characterized as innervated by the obturator nerve, and AM4 corresponds to the hamstrings part, innervated by the sciatic nerve. Here, we showed that the sciatic nerve supplies not only the hamstrings part but also the adductor part. These two nerves spread more widely than has generally been believed, which could have practical implications for the assessment and treatment of motor disability. PMID:23813615

  20. Taxonomic studies on a new marine ciliate, Apocoleps magnus gen. nov., spec. nov. (Ciliophora, Colepidae), isolated from Qingdao, China

    NASA Astrophysics Data System (ADS)

    Chen, Xiangrui; Warren, Alan; Song, Weibo

    2009-12-01

    The morphology and infraciliature of a new marine colepid ciliate, Apocoleps magnus gen. nov., spec. nov., are described based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 (vs. 6 in most other related genera) armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apocoleps magnus spec. nov. is defined by the following features: body elongated and slightly curved, about 100-120µm× 35-45 µm in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.

  1. Floquet resonant states and validity of the Floquet-Magnus expansion in the periodically driven Friedrichs models

    NASA Astrophysics Data System (ADS)

    Mori, Takashi

    2015-02-01

    The Floquet eigenvalue problem is analyzed for periodically driven Friedrichs models on discrete and continuous space. In the high-frequency regime, there exists a Floquet bound state consistent with the Floquet-Magnus expansion in the discrete Friedrichs model, while it is not the case in the continuous model. In the latter case, however, the bound state predicted by the Floquet-Magnus expansion appears as a metastable state whose lifetime diverges in the limit of large frequencies. We obtain the lifetime by evaluating the imaginary part of the quasienergy of the Floquet resonant state. In the low-frequency regime, there is no Floquet bound state and instead the Floquet resonant state with exponentially small imaginary part of the quasienergy appears, which is understood as the quantum tunneling in the energy space.

  2. Investigation of the effect of finite pulse errors on the BABA pulse sequence using the Floquet-Magnus expansion approach

    NASA Astrophysics Data System (ADS)

    Mananga, Eugene S.; Reid, Alicia E.

    2013-01-01

    This paper presents a study of finite pulse widths for the BABA pulse sequence using the Floquet-Magnus expansion (FME) approach. In the FME scheme, the first order ? is identical to its counterparts in average Hamiltonian theory (AHT) and Floquet theory (FT). However, the timing part in the FME approach is introduced via the ? function not present in other schemes. This function provides an easy way for evaluating the spin evolution during the time in between' through the Magnus expansion of the operator connected to the timing part of the evolution. The evaluation of ? is particularly useful for the analysis of the non-stroboscopic evolution. Here, the importance of the boundary conditions, which provide a natural choice of ? , is ignored. This work uses the ? function to compare the efficiency of the BABA pulse sequence with ? and the BABA pulse sequence with finite pulses. Calculations of ? and ? are presented.

  3. Interaction of the topological phase and the Magnus effect in a multimode fiber

    NASA Astrophysics Data System (ADS)

    Aleksiev, A.; Modnikova, E.; Fadeyeva, Tatyana A.; Lapayeva, S. N.; Volyar, Alexander V.

    1996-04-01

    The phenomenon of a light topological birefringence in a multimode fiber has been discussed in papers. The physical mechanism of the topological birefringence, as expected earlier is determined by the interaction of the two effects, namely, the topological Berry's phase and the optical Magnus effect. So, for a square distribution of a refractive index in a fiber cross section the near-meridianal local waves propagate along ray trajectories represented by strongly stretched ellipses of an elliptical helix. A plane made by a fiber axis and a major axis of a ray elliptical helix undergoes a rotation into the fiber, and the rotation hand of this plane is defined by a sign of the wave polarization circularity. If a linear polarized light drops into a fiber input its left-hand polarized component will rotate the major axis of the elliptical helix counterclockwise, and the right-hand polarized component rotates clockwise. Since the angular rates of this rotation are slightly different one from another forthcoming the local waves having counter circulation of a polarization should be collapsed in a single linear polarized local wave. However if the local wave trajectory doesn't lie in a plane then it is a space curve.

  4. An analysis of texture, timbre, and rhythm in relation to form in Magnus Lindberg's "Gran Duo"

    NASA Astrophysics Data System (ADS)

    Wolfe, Brian Thomas

    Gran Duo (1999-2000) by Magnus Lindberg (b. 1958) is the result of a commission by Sir Simon Rattle, former conductor of the City of Birmingham (England) Symphony Orchestra, and the Royal Festival Hall to commemorate the third millennium. Composed for twenty-four woodwinds and brass, Lindberg divides the woodwind and brass families into eight characters that serve as participants in an attentive twenty-minute conversation. The document includes biographical information about the composition to further understand Lindberg's writing style. The composer's use of computer-assisted composition techniques inspires an alternative structural analysis of Gran Duo. Spectral graphs provide a supplementary tool for score study assisting with the verification of formal structural elements. A tempo chart allows the conductor to easily identify form and tempo relationships between each of the nineteen sections throughout the five-movement composition. In order to reveal character areas and their relation to the structure of the work, the analysis of texture, timbre, and rhythm reveal the formal structure of the composition, which reflects a conversation between the brass and woodwinds in this setting for wind instruments.

  5. Floquet-Magnus theory and generic transient dynamics in periodically driven many-body quantum systems

    NASA Astrophysics Data System (ADS)

    Kuwahara, Tomotaka; Mori, Takashi; Saito, Keiji

    2016-04-01

    This work explores a fundamental dynamical structure for a wide range of many-body quantum systems under periodic driving. Generically, in the thermodynamic limit, such systems are known to heat up to infinite temperature states in the long-time limit irrespective of dynamical details, which kills all the specific properties of the system. In the present study, instead of considering infinitely long-time scale, we aim to provide a general framework to understand the long but finite time behavior, namely the transient dynamics. In our analysis, we focus on the Floquet-Magnus (FM) expansion that gives a formal expression of the effective Hamiltonian on the system. Although in general the full series expansion is not convergent in the thermodynamics limit, we give a clear relationship between the FM expansion and the transient dynamics. More precisely, we rigorously show that a truncated version of the FM expansion accurately describes the exact dynamics for a certain time-scale. Our theory reveals an experimental time-scale for which non-trivial dynamical phenomena can be reliably observed. We discuss several dynamical phenomena, such as the effect of small integrability breaking, efficient numerical simulation of periodically driven systems, dynamical localization and thermalization. Especially on thermalization, we discuss a generic scenario on the prethermalization phenomenon in periodically driven systems.

  6. Black holes and fundamental fields: Hair, kicks, and a gravitational Magnus effect

    NASA Astrophysics Data System (ADS)

    Okawa, Hirotada; Cardoso, Vitor

    2014-11-01

    Scalar fields pervade theoretical physics and are a fundamental ingredient to solve the dark matter problem, to realize the Peccei-Quinn mechanism in QCD or the string-axiverse scenario. They are also a useful proxy for more complex matter interactions, such as accretion disks or matter in extreme conditions. Here, we study the collision between scalar "clouds" and rotating black holes. For the first time we are able to compare analytic estimates and strong field, nonlinear numerical calculations for this problem. As the black hole pierces through the cloud it accretes according to the Bondi-Hoyle prediction, but is deflected through a purely kinematic gravitational "anti-Magnus" effect, which we predict to be present also during the interaction of black holes with accretion disks. After the interaction is over, we find large recoil velocities in the transverse direction. The end-state of the process belongs to the vacuum Kerr family if the scalar is massless, but can be a hairy black hole when the scalar is massive.

  7. Metamaterials with tunable refractive index fabricated from amorphous ferromagnetic microwires and optical Magnus effect

    NASA Astrophysics Data System (ADS)

    Ivanov, Andrey; Vedyayev, Anatoly; Galkin, Vladimir; Shalygin, Alexander; Ivanov, Valery

    2009-03-01

    For homogeneous NPVM (negative phase--velocity mediums) [V. G. Veselago, Soviet Physics - Uspekhi 10 (1968) 509; T. G. Mackay, A. Lakhtakia, Phys. Rev. E 69 (2004) 026602] anomalous effects such as negative refraction, light pressure, Doppler shift, Cherenkov-Vavilov radiation, Goos-Hanchen effect have been discovered in different frequency ranges. In this presentation the optical circular polarized effect is calculated for inhomogeneous mediums (optical Magnus effect) and it is shown that it is anomalous in NPVM with respect to ``right-handed'' materials. The proposed metamaterials fabricated from glass coated amorphous ferromagnetic Co-Fe-Cr-B-Si microwires are shown to exhibit a negative refractive index for electromagnetic waves over scale of GHz frequencies [A.V. Ivanov, A.N. Shalygin, A.V. Vedyayev, V.A. Ivanov, JETP Letters 85 (2007) 565]. The magnetostatic interaction between microwires has been taken into account. The phase and group velocities in proposed metamaterial have been calculated. The ratio of thereof depends monotonically on the size of the microwires. Optical properties of such metamaterials are tunable by an external magnetic field and mechanical stress.

  8. The Sexologist Albert Moll – between Sigmund Freud and Magnus Hirschfeld

    PubMed Central

    Sigusch, Volkmar

    2012-01-01

    Albert Moll was one of the most influential sexologists during the first three decades of the twentieth century. In contrast to his rivals Sigmund Freud and Magnus Hirschfeld, his achievements have not yet been recognised adequately. The author gives a comparative account of the work of these three protagonists. This shows that Moll formed some ideas which are regarded as psychoanalytical today before Freud, and that he, in contrast to Hirschfeld, was able to reflect critically on contemporary discourses, such as the debates on racial improvement through eugenics. As scientific theories, Freud’s psychoanalysis represented the unconscious, fantasy, experience and latency, while Moll’s sexology represented consciousness, ontological reality, behaviour and manifestation. Moll’s major disagreement with Hirschfeld’s sexology was his advocacy of apolitical and impartial science, whereas Hirschfeld’s aim was to achieve sexual reforms politically. Added to these differences were strong personal animosities. Freud called Moll a ‘beast’ and ‘pettifogger’; and Moll complained about Hirschfeld’s ‘problematic’ character. When Hirschfeld escaped the Nazi terror and went to Paris, Moll denounced him in order to prevent him rebuilding a new existence in exile. PMID:23002292

  9. Serotonergic raphe magnus cell discharge reflects on-going autonomic and respiratory activities

    PubMed Central

    Mason, Peggy; Gao, Keming; Genzen, Jonathan R.

    2013-01-01

    Serotonergic cells are located in a restricted number of brainstem nuclei, send projections to virtually all parts of the central nervous system, and are critical to normal brain function. They discharge tonically at a rate modulated by sleep/wake cycle and, in the case of medullary serotonergic cells in raphe magnus and the adjacent reticular formation (RM), are excited by cold challenge. Yet, beyond behavioral state and cold, endogenous factors that influence serotonergic cell discharge remain largely mysterious. The present study in the anesthetized rat investigated predictors of serotonergic RM cell discharge by testing whether cell discharge correlated to three rhythms observed in blood pressure recordings that averaged >30 minutes in length. A very slow frequency rhythm with a period of minutes, a respiratory rhythm, and a cardiac rhythm were derived from the blood pressure recording. Cross correlations between each of the derived rhythms and cell activity revealed that the discharge of 38 of the 40 serotonergic cells studied was significantly correlated to the very slow and/or respiratory rhythms. Very few serotonergic cells discharged in relation to the cardiac cycle and those that did, did so weakly. The correlations between serotonergic cell discharge and the slow and respiratory rhythms cannot arise from baroreceptive input. Instead we hypothesize that they are by-products of on-going adjustments to homeostatic functions that happen to alter blood pressure. Thus, serotonergic RM cells integrate information about multiple homeostatic activities and challenges and can consequently modulate spinal processes according to the most pressing need of the organism. PMID:17715191

  10. Authigenic albite formation due to water-rock interactions - Case study: Magnus oilfield (UK, Northern North Sea)

    NASA Astrophysics Data System (ADS)

    Mu, Nana; Fu, Yunjiao; Schulz, Hans-Martin; van Berk, Wolfgang

    2016-01-01

    It is the aim of this contribution to test whether organic-inorganic interactions could induce the formation of authigenic albite. This concept and related results are being compared with modelling scenarios which are purely based on inorganic geochemical reactions. In order to unravel the pathway of authigenic albite formation, this paper presents results of a multidisciplinary study from imaging, geochemistry, mineralogy, and hydrogeochemical modelling. The Jurassic reservoir sandstones of the Magnus oilfield (UK, North Sea) were chosen as a test site. Albite occurs with 4-18 wt.% in the Magnus sandstones and its contents vary with depth. However, albite contents increase with increasing K-feldspar contents and decreasing grain size. It occurs in three forms: (1) as lamellae in perthite, (2) as overgrowth on/in corroded feldspar, and, (3) as cloudy replacing albite patches in K-feldspar. The albite overgrowth has the highest chemical purity (100% albite) whilst albite lamellae and replacing albite patches are slightly less pure (containing 1-4% anorthite). Albite appears non-altered, and has a euhedral morphology and dull cathodoluminescence. It commonly co-occurs with corroded K-feldspar grains. The precipitation of diagenetic albite in the Magnus sandstones is attributed to deep burial 80 Ma ago and may have continued until today at temperatures between 90-120 °C. The results of hydrogeochemical modelling offer two possible pathways for the authigenic albite formation: (1) Dissolution of unstable minerals (such as kaolinite and chalcedony) coupled to reduction of ferric iron minerals by products generated during oil generation, migration and degradation; (2) Dissolution of non-end member feldspar, such as K-feldspar with 10% albite, coupled to illite formation can account for trace amounts of albite due to an elevated Na+/K+ activity ratio in the pore water.

  11. Vortex currents in turbulent superfluid and classical fluid channel flow, the magnus effect, and Goldstone boson fields

    SciTech Connect

    Huggins, E.R. )

    1994-09-01

    Expressing hydrodynamics in terms of the flow of vorticity, using the vortex current tensor, helps unify the picture of turbulent channel flow for viscous fluids and for superfluids. In both, eddy viscosity plays a major role in energy dissipation, and in both there is a similar cross stream flow of vorticity, which in the case of superfluids leads to the Josephson frequency. The vortex current tensor, which was introduced in an earlier paper to derive an exact three dimensional Magnus effect formula, turns out to be the classical hydrodynamic limit of the vortex current that is the source for a classical Goldstone-boson field.

  12. Reproductive cycle of Ensis magnus in the Ría de Pontevedra (NW Spain): Spatial variability and fisheries management implications

    NASA Astrophysics Data System (ADS)

    Hernández-Otero, A.; Martínez-Castro, C.; Vázquez, E.; Macho, G.

    2014-08-01

    Mesoscale differences in the reproductive cycle of the commercial sword razor clam Ensis magnus (Schumacher, 1817) were studied in six shellfish beds in the Ría de Pontevedra (NW Spain) between March 2008 and July 2010. The GCI accurately described the reproductive cycle as indicated by the histological analysis. Both methods showed that the reproductive cycle was similar at different sites and was characterized by a resting stage during summer and early autumn, initiation of gametogenesis in autumn and a period of successive spawning interspersed with gonad recovery during winter and spring. However, a 15-day to one month delay in advanced stages of gametogenesis and maturation was observed between the inner and the outermost site of the ria, as well as an extended spawning period in the outermost area. Lower bottom seawater temperatures at the outermost sites appeared to delay maturation and to prolong the spawning periods, whereas salinity fluctuations at the innermost sites appeared to reduce the length of the cycle. This study provides the first estimation of the size at which E. magnus reaches sexual maturity in the Iberian Peninsula, determined in 79 mm, and it is also the first work in determining the mesoscale variation in gonadal development of any species of the superfamily Solenoidea. The results highlight the importance of carrying out mesoscale studies of the reproductive biology in coastal fisheries resources. Some of the findings of the present study have already been applied in the rotation scheme of the fishery harvesting plan.

  13. Applications of Floquet-Magnus expansion, average Hamiltonian theory and Fer expansion to study interactions in solid state NMR when irradiated with the magic-echo sequence.

    PubMed

    Mananga, Eugene Stephane

    2013-01-01

    This work presents the possibility of applying the Floquet-Magnus expansion and the Fer expansion approaches to the most useful interactions known in solid-state nuclear magnetic resonance using the magic-echo scheme. The results of the effective Hamiltonians of these theories and average Hamiltonian theory are presented. PMID:24034855

  14. Bioactivation of cysteine conjugates of 1-nitropyrene oxides by cysteine conjugate beta-lyase purified from Peptostreptococcus magnus.

    PubMed Central

    Kataoka, K; Kinouchi, T; Akimoto, S; Ohnishi, Y

    1995-01-01

    To determine the role of cysteine conjugate beta-lyase (beta-lyase) in the metabolism of mutagenic nitropolycyclic aromatic hydrocarbons, we determined the effect of beta-lyase on the mutagenicities and DNA binding of cysteine conjugates of 4,5-epoxy-4,5-dihydro-1-nitropyrene (1-NP 4,5-oxide) and 9,10-epoxy-9,10-dihydro-1-nitropyrene (1-NP 9,10-oxide), which are detoxified metabolites of the mutagenic compound 1-nitropyrene. We purified beta-lyase from Peptostreptococcus magnus GAI0663, since P. magnus is one of the constituents of the intestinal microflora and exhibits high levels of degrading activity with cysteine conjugates of 1-nitropyrene oxides (1-NP oxide-Cys). The activity of purified beta-lyase was optimal at pH 7.5 to 8.0, was completely inhibited by aminooxyacetic acid and hydroxylamine, and was eliminated by heating the enzyme at 55 degrees C for 5 min. The molecular weight of beta-lyase was 150,000, as determined by fast protein liquid chromatography. S-Arylcysteine conjugates were good substrates for this enzyme. As determined by the Salmonella mutagenicity test, 5 ng of beta-lyase protein increased the mutagenicity of the cysteine conjugate of 1-NP 9,10-oxide (10 nmol per plate) 4.5-fold in Salmonella typhimurium TA98 and 4.1-fold in strain TA100. However, beta-lyase had little effect on the cysteine conjugate of 1-NP 4,5-oxide (10 nmol per plate). Both conjugates exhibited only low levels of mutagenicity with nitroreductase-deficient strain TA98NR. In vitro binding of 1-NP oxide-Cys to calf thymus DNA was increased by adding purified beta-lyase or xanthine oxidase.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8526486

  15. Mercury and sulphur among the High Medieval alchemists: from Rāzī and Avicenna to Albertus Magnus and pseudo-Roger Bacon.

    PubMed

    Newman, William R

    2014-11-01

    This essay challenges the often expressed view that the principles of metals, namely mercury and sulphur, were generally viewed by alchemists as being of a 'metaphysical' character that made them inaccessible to the tools and operations of the laboratory. By examining a number of Arabo-Latin and Latin alchemical texts in circulation before the end of the thirteenth century, the author presents evidence that most alchemists of the period considered mercury and sulphur to be materials subject to techniques of purification in the same way that naturally occurring salts and minerals could be freed of their impurities or dross. The article also points to the immense influence of Avicenna and Albertus Magnus in formulating the theory that mercury and sulphur were compounds of different materials, containing both fixed and unfixed components. Finally, the author briefly examines the relationship between this materialist approach to the principles and the chymical atomism of early modern authors who were deeply aware of medieval alchemical literature. PMID:25509633

  16. SPATIAL AND TEMPORAL PATTERNS OF SEROTONIN RELEASE IN THE RAT’S LUMBAR SPINAL CORD FOLLOWING ELECTRICAL STIMULATION OF THE NUCLEUS RAPHE MAGNUS

    PubMed Central

    Hentall, I. D.; Pinzon, A.; Noga, B. R.

    2009-01-01

    The monoamine neurotransmitter serotonin is released from spinal terminals of nucleus raphe magnus (NRM) neurons and important in sensory and motor control, but its pattern of release has remained unclear. Serotonin was measured by the high-resolution method of fast cyclic voltammetry (2 Hz) with carbon-fiber microelectrodes in lumbar segments (L3–L6) of halothane-anesthetized rats during electrical stimulation of the NRM. Because sites of serotonin release are often histologically remote from membrane transporters and receptors, rapid emergence into aggregate extracellular space was expected. Increased monoamine oxidation currents were found in 94% of trials of 50-Hz, 20-s NRM stimulation across all laminae. The estimated peak serotonin concentration averaged 37.8 nM (maximum 287 nM), and was greater in dorsal and ventral laminae (I–III and VIII–IX) than in intermediate laminae (IV–VI). When measured near NRM-evoked changes, basal monoamine levels (relative to dorsal white matter) were highest in intermediate laminae, while changes in norepinephrine level produced by locus ceruleus (LC) stimulation were lowest in laminae II/III and VII. The NRM-evoked monoamine peak was linearly proportional to stimulus frequency (10–100 Hz). The peak often occurred before the stimulus ended (mean 15.6 s at 50 Hz, range 4–35 s) regardless of frequency, suggesting that release per impulse was constant during the rise but fell later. The latency from stimulus onset to electrochemical signal detection (mean 4.2 s, range 1–23 s) was inversely correlated with peak amplitude and directly correlated with time-to-peak. Quantitative modeling suggested that shorter latencies mostly reflected the time below detection threshold (5–10 nM), so that extrasynaptic serotonin was significantly elevated well within 1 s. Longer latencies (>5 s), which were confined to intermediate laminae, appeared mainly to be due to diffusion from distant sources. In conclusion, except possibly in

  17. Magnus and Iordanskii Forces in Superfluids

    SciTech Connect

    Wexler, C.

    1997-08-01

    The transverse force acting on a quantized vortex in a superfluid is a problem that has eluded a complete understanding for more than three decades. In this Letter I calculate the {ital superfluid } velocity part of the transverse force in a way closely related to Laughlin{close_quote}s argument for the quantization of conductance in the quantum Hall effect. A combination of this result, the {ital vortex} velocity part of the transverse force found by Thouless, Ao, and Niu [Phys.Rev.Lett.{bold 76}, 3758 (1996)], and Galilean invariance shows that there cannot be a transverse force proportional to the normal fluid velocity. {copyright} {ital 1997} {ital The American Physical Society}

  18. Improved Magnus` form approximation of saturation vapor pressure

    SciTech Connect

    Alduchov, O.A.; Eskridge, R.E.

    1997-11-01

    Relative humidity is usually measured in aerological observations and dew point depression is usually reported in upper-air reports. These variables must frequently be converted to other moisture variables in meteorological analysis. If relative humidity is converted to vapor pressure, most humidity variables can then be determined. Elliott and Gaffen reviewed the practices and procedures of the US radiosonde system. In their paper, a comparison of the relative errors was made between the saturation vapor pressure formulations of Tetens (1930), Goff-Gratch (1946), Wexler (1976), and Buck (1981). In this paper, the authors will expand the analysis of Elliott and Gaffen by deriving several new saturation vapor pressure formulas, and reviewing the various errors in these formulations. They will show that two of the new formulations of vapor pressure over water and ice are superior to existing formulas. Upper air temperature data are found to vary from about +50 C to {minus}80 C. This large variation requires a saturation vapor pressure equation to be accurate over a large temperature range. While the errors introduced by the use of relatively inaccurate conversion equations are smaller than the errors due to the instruments, dewpoint coding errors, and dewpoint conversion algorithms (Elliott and Gaffen, 1993); they introduce additional systematic errors in humidity data. The most precise formulation of vapor pressure over a plane surface of water was given by Wexler (1976). The relative errors of Tetens` (1930) formula and one due to Buck (1981) (Buck`s equation is recommended in the Federal Meteorological Handbook No. 3, 1991) are shown. The relative errors in this table are the predicted value minus the Wexler value divided by the Wexler value.

  19. One-dimensional Magnus-type platinum double salts

    PubMed Central

    Hendon, Christopher H.; Walsh, Aron; Akiyama, Norinobu; Konno, Yosuke; Kajiwara, Takashi; Ito, Tasuku; Kitagawa, Hiroshi; Sakai, Ken

    2016-01-01

    Interest in platinum-chain complexes arose from their unusual oxidation states and physical properties. Despite their compositional diversity, isolation of crystalline chains has remained challenging. Here we report a simple crystallization technique that yields a series of dimer-based 1D platinum chains. The colour of the Pt2+ compounds can be switched between yellow, orange and blue. Spontaneous oxidation in air is used to form black Pt2.33+ needles. The loss of one electron per double salt results in a metallic state, as supported by quantum chemical calculations, and displays conductivity of 11 S cm−1 at room temperature. This behaviour may open up a new avenue for controllable platinum chemistry. PMID:27320502

  20. One-dimensional Magnus-type platinum double salts.

    PubMed

    Hendon, Christopher H; Walsh, Aron; Akiyama, Norinobu; Konno, Yosuke; Kajiwara, Takashi; Ito, Tasuku; Kitagawa, Hiroshi; Sakai, Ken

    2016-01-01

    Interest in platinum-chain complexes arose from their unusual oxidation states and physical properties. Despite their compositional diversity, isolation of crystalline chains has remained challenging. Here we report a simple crystallization technique that yields a series of dimer-based 1D platinum chains. The colour of the Pt(2+) compounds can be switched between yellow, orange and blue. Spontaneous oxidation in air is used to form black Pt(2.33+) needles. The loss of one electron per double salt results in a metallic state, as supported by quantum chemical calculations, and displays conductivity of 11 S cm(-1) at room temperature. This behaviour may open up a new avenue for controllable platinum chemistry. PMID:27320502

  1. Response to Yiannis Miralis, "Manos Hadjidakis: The Story of an Anarchic Youth and a "Magnus Eroticus""

    ERIC Educational Resources Information Center

    Helfer, Jason

    2004-01-01

    There are two issues that struck the author, Jason Helfer, as essential from his consideration of Miralis' paper and the ideas of Manos Hadjidakis: Eros as a pedagogical idea and learner interactions in the music classroom. These ideas developed from his interpretation of Miralis' paper, from his experiences in teacher training, and teaching in…

  2. Albertus, "Magnus" or Magus? Magic, natural philosophy, and religious reform in the late middle ages.

    PubMed

    Collins, David J

    2010-01-01

    This article analyzes the fifteenth-century attempt by the Dominican order, especially in Cologne, to win canonization for the thirteenth-century natural philosopher Albert the Great. It shows how Albert's thought on natural philosophy and magic was understood and variously applied, how the Dominicans at Cologne composed his vitae, and how the order's Observant movement participated in these developments. It situates the canonization attempt at the intersection of two significant trends in which the order was a leading participant: first, the late medieval efforts to reform Christian society beginning with the religious life of monks and mendicants; second, the increasing concerns about the practice of learned and demonic mafic that laid groundwork for the witch-hunting of the early modern period. This article aims to shed light on intersections of science and religion -- their apprehension and negotiation -- at a decisive moment in European history for both fields of human endeavor. PMID:20527358

  3. Manos Hadjidakis: The Story of an Anarchic Youth and a "Magnus Eroticus"

    ERIC Educational Resources Information Center

    Miralis, Yiannis

    2004-01-01

    The name of Manos Hadjidakis is probably unknown to contemporary musicians and music educators. After all, the Greek composer achieved his international fame back in 1961 when he won an Oscar for his soundtrack of the movie, "Never on Sunday." Numerous other awards followed from England, Krance, Germany, and of course, Greece. After his six years…

  4. Cooperative excited-state behavior in plantinum(II) magnus-type double-salt materials. Active and inactive photosensitizers for H/sub 2/ production in aqueous suspension

    SciTech Connect

    Houlding, V.H.; Frank, A.J.

    1985-10-23

    Diffuse-reflectance and emission behavior are used to characterize the lowest excited state of the following (Pt/sup II//sup 2 +/(Pt/sup II/)/sup 2 +/ double salts and in some cases their hydrates: (Pt(NH/sub 34/)(PtCl/sub 4/) (MGS), (Pt(bpy)/sub 2/)(PtCl/sub 4/) (PB(Cl); bpy = 2,2'-bipyridine), (Pt-(bpy)(MHB))(PtCl/sub 4/) (PHB(Cl); MHB = 4-methyl-4'-heptyl-2,2'-bipyridine), )Pt(bpy)/sub 2/)(Pt(CN)/sub 4/) (PBC), and (Pt(bpy)-(MHB))(Pt(CN)/sub 4/)(PHBC). All of the salts containing the PtCl/sub 4//sup 2 -/ anion have lowest excited states of the ligand field type. In green MGS, where metal-metal interaction is significant, no emission occurs, but in yellow PB(Cl)x2.5H/sub 2/O and PHBC x 2.5 H/sub 2/O where interaction is weak, emission characteristic of PtCl/sub 2//sup 2 -/ is observed. In orange PBCx2H/sub 2/O and PHB(Cl), and their red anhydrates, the lowest excited state is assigned as a delocalized /sup 3/Pt(5d/sub z/sup 2//-6p/sub z/) state. Both salts exhibit strong emission (in PBC powder at room temperature, the emission quantum yield is 0.002 +/- 0.001 and the lifetime is 16.8 +/- 2.5 ns), which overlaps well with an intense visible absorption band. PBC and PHBC powders are active as photosensitizers for the reduction of water in EDTA solutions. In the presence of Pt(0) catalyst, H/sub 2/ production is sustained at a constant rate to >1 turnover with respect to photosensitizer, with no evidence for photosensitizer degradation. In the absence of Pt(0), PBC produces H/sub 2/ at a constant rate that is less than 1% of the rate of the presence of Pt(0), but again, without degradation. MGS, PB(Cl), and PHB(Cl) are photoinert and completely inactive as photosensitzers in this reaction. 31 references, 1 figure, 1 table.

  5. Interaction of ultrasound with vortices in type-II superconductors

    SciTech Connect

    Sonin, E.B.

    1996-04-01

    The theory of ultrasound in the mixed state of type-II superconductors is suggested which takes into account the Magnus force on vortices, the anti-Magnus force on ions, and diamagnetism of the mixed state. The acoustic Faraday effect (rotation of polarization of the transverse ultrasonic wave propagating along vortices) is linear in the Magnus force in any regime of the flux flow for wavelengths now used in the ultrasound experiments. Therefore, in contrast to previous predictions, the Faraday effect should be looked for only in clean superconductors with a strong Magnus force. {copyright} {ital 1996 The American Physical Society.}

  6. Transverse forces on a vortex in lattice models of superfluids

    NASA Astrophysics Data System (ADS)

    Sonin, E. B.

    2013-12-01

    The paper derives the transverse forces (the Magnus and the Lorentz forces) in the lattice models of superfluids in the continuous approximation. The continuous approximation restores translational invariance absent in the original lattice model, but the theory is not Galilean invariant. As a result, calculation of the two transverse forces on the vortex, Magnus force and Lorentz force, requires the analysis of two balances, for the true momentum of particles in the lattice (Magnus force) and for the quasimomentum (Lorentz force) known from the Bloch theory of particles in the periodic potential. While the developed theory yields the same Lorentz force, which was well known before, a new general expression for the Magnus force was obtained. The theory demonstrates how a small Magnus force emerges in the Josephson-junction array if the particle-hole symmetry is broken. The continuous approximation for the Bose-Hubbard model close to the superfluid-insulator transition was developed, which was used for calculation of the Magnus force. The theory shows that there is an area in the phase diagram for the Bose-Hubbard model, where the Magnus force has an inverse sign with respect to that which is expected from the sign of velocity circulation.

  7. Final Shuttle Crew Recaps Mission for Dryden Staff - Duration: 110 seconds.

    NASA Video Gallery

    STS-135 crew members, commander Chris Ferguson, pilot Doug Hurley and mission specialists Sandy Magnus and Rex Walheim, recalled personal highlights of the final shuttle mission and their involveme...

  8. An analytical treatment for three neutrino oscillations in the Earth

    NASA Astrophysics Data System (ADS)

    Aguilar-Arevalo, A. A.; D'Olivo, J. C.; Supanitsky, A. D.

    2012-08-01

    A simple, and at the same time accurate, description of the Earth matter effects on the oscillations between three neutrino flavors is given in terms of the Magnus expansion for the evolution operator.

  9. Sir Paul McCartney Wake-up Song and Greeting

    NASA Video Gallery

    Paul McCartney and Beatles favorite "Good Day Sunshine" greet the Atlantis crew of Chris Ferguson, Doug Hurley, Sandy Magnus and Rex Walheim first thing on Flight Day 8. Sir Paul and the Beatles’...

  10. Stennis Space Center Wakes STS-135 Crew - Duration: 116 seconds.

    NASA Video Gallery

    The Flight Day 10 wakeup music was “Celebration” by Kool and the Gang, which was played for Mission Specialist Sandy Magnus. The song was accompanied by a special good morning message recorded ...

  11. Effects of central opiate and serotoninergic structures on heart rhythm during acute myocardial ischemia.

    PubMed

    Prokop'eva, E V; Pivovarov, Y I

    2001-12-01

    Electrostimulation of the central gray matter in the sylvian aqueduct and nucleus raphe magnus produced an antiarrhythmic effect during acute myocardial ischemia. Stimulation and blockade of opiate receptors in the central amygdaloid nucleus and lateral hypothalamus with dalargin and naloxone induced the same effect. Destruction of the central gray matter in the sylvian aqueduct and nucleus raphe magnus decreased electrical stability of ischemic myocardium. PMID:12152875

  12. Simulation of aeolian sand saltation with rotational motion

    NASA Astrophysics Data System (ADS)

    Huang, Ning; Wang, Cong; Pan, Xiying

    2010-11-01

    In this work, we propose a theoretical model based on the distribution functions of initial liftoff velocity and angular velocity of sand grains to describe a sand saltation process in which both wind field-sand grain coupling and the Magnus force experienced by saltating sand grains have been incorporated. The computation results showed that the Magnus force had significant effects on sand grain saltation. In particular, when the Magnus force was incorporated, the calculated sand transport fluxes and sand transport rate per unit width were closer to the experimental value than when this force was excluded. The sand transport flux is enhanced because the Magnus force owing to particle rotation causes the particles to have higher and longer trajectories, so the particles can get more speed and energy from the wind, which leads to a larger sand transport flux. In addition, it was found that when taking the Magnus force into account, the probability density of the impact velocity and angular velocity of saltating sand grains followed an exponential distribution and a unimodal asymmetric distribution, respectively. Moreover, the sand energy flux increased with the height above the sand surface until the energy flux reached its maximum and then decreased. Furthermore, the energy flux near the ground surface decreased as the grain diameter increased, but beyond a specific height the energy flux increased with the grain diameter. Finally, for the same sand grain diameter, the energy flux increased with the friction velocity.

  13. Vortices in superconducting films: Statistics and fractional quantum Hall effect

    SciTech Connect

    Dziarmaga, J.

    1996-03-01

    We present a derivation of the Berry phase picked up during exchange of parallel vortices. This derivation is based on the Bogolubov{endash}de Gennes formalism. The origin of the Magnus force is also critically reanalyzed. The Magnus force can be interpreted as an interaction with the effective magnetic field. The effective magnetic field may be even of the order 10{sup 6}{ital T}/A. We discuss a possibility of the fractional quantum Hall effect (FQHE) in vortex systems. As the real magnetic field is varied to drive changes in vortex density, the vortex density will prefer to stay at some quantized values. The mere existence of the FQHE does not depend on vortex quantum statistics, although the pattern of the plateaux does. We also discuss how the density of anyonic vortices can lower the effective strengh of the Magnus force, what might be observable in measurements of Hall resistivity. {copyright} {ital 1996 The American Physical Society.}

  14. STS-112 Flight Day 8 Highlights

    NASA Astrophysics Data System (ADS)

    2002-10-01

    On this eighth day of the STS-112 mission, the crew members of Atlantis (Commander Jeff Ashby; Pilot Pam Melroy; Mission Specialists Sandy Magnus, Piers Sellers, Dave Wolf, and Fyodor Yurchikhin) are seen preparing for the mission's third extravehicular activity (EVA). Magnus is shown reviewing instructions for operation of the International Space Station's (ISS) robot arm. Wolf and Sellers are seen successfully attaching cable connections to the S1 truss during the EVA. Scenes shown include: the ISS's robot arm, the Crew Equipment Translation Aid (CETA) cart and the deployment of the central radiator panel of the S1 truss.

  15. STS-112 Flight Day 8 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On this eighth day of the STS-112 mission, the crew members of Atlantis (Commander Jeff Ashby; Pilot Pam Melroy; Mission Specialists Sandy Magnus, Piers Sellers, Dave Wolf, and Fyodor Yurchikhin) are seen preparing for the mission's third extravehicular activity (EVA). Magnus is shown reviewing instructions for operation of the International Space Station's (ISS) robot arm. Wolf and Sellers are seen successfully attaching cable connections to the S1 truss during the EVA. Scenes shown include: the ISS's robot arm, the Crew Equipment Translation Aid (CETA) cart and the deployment of the central radiator panel of the S1 truss.

  16. Numerical simulation of steady supersonic flow over spinning bodies of revolution

    NASA Technical Reports Server (NTRS)

    Sturek, W. B.; Schiff, L. B.

    1982-01-01

    A recently reported parabolized Navier-Stokes code has been employed to compute the supersonic flowfield about a spinning cone and spinning and nonspinning ogive cylinder and boattailed bodies of revolution at moderate incidence. The computations were performed for flow conditions where extensive measurements for wall pressure, boundary-layer velocity profiles, and Magnus force had been obtained. Comparisons between the computational results and experiment indicate excellent agreement for angles of attack up to 6 deg. At angles greater than 6 deg discrepancies are noted which are tentatively attributed to turbulence modeling errors. The comparisons for Magnus effects show that the code accurately predicts the effects of body shape for the selected models.

  17. Viscous flow over spinning cones at angle of attack.

    NASA Technical Reports Server (NTRS)

    Lin, T. C.; Rubin, S. G.

    1973-01-01

    A numerical finite-difference method is developed for evaluating the Magnus coefficients on spinning cones in laminar flow. The merged layer, the strong interaction region, and the downstream boundary layer are all considered. The numerical method is a predictor-corrector scheme developed for three-dimensional flows with or without crossflow diffusion. This method is particularly useful in problems in which a symmetry plane does not exist. Several contributions to the Magnus force and moments are considered. These include asymmetries in displacement thickness, centrifugal force and crossflow shear, and the effects of crossflow separation and vortex formation. Comparisons are made with experimental data and other analyses.

  18. Hypersonic Laminar Viscous Flow Past Spinning Cones at Angle of Attack

    NASA Technical Reports Server (NTRS)

    Agarwal, Ramesh; Rakich, John V.

    1982-01-01

    Computational results are presented for hypersonic viscous flow past spinning sharp and blunt cones of angle of attack, obtained with a parabolic Navier-Stokes marching code. The code takes into account the asymmetries in the flowfield resulting from spinning motion and computes the asymmetric shock shape, cross-flow and streamwise shear, heat transfer, cross-flow separation, and vortex structure. The Magnus force and moments are also computed. Comparisons are made with other theoretical analyses based on boundary-layer and boundary-region equations, and an anomaly is discovered in the displacement thickness contribution to the Magnus force when compared with boundary-layer results.

  19. Interaction of vortex lattice with ultrasound and the acoustic Faraday effect

    SciTech Connect

    Dominguez, D.; Bulaevskii, L.; Ivlev, B.; Maley, M.; Bishop, A.R. |

    1995-03-27

    The interaction of sound with the vortex lattice is considered for high-{ital T}{sub {ital c}} superconductors, taking into account pinning and electrodynamic forces between vortices and crystal displacements. At low temperatures the Magnus force results in the acoustic Faraday effect; the velocity of sound propagating along the magnetic field depends on the polarization. This effect is linear in the Magnus force and magnetic field in crystals with equivalent {ital a} and {ital b} axes for a field parallel to the {ital c} axis. In the thermally activated flux flow regime, the Faraday effect is caused by electric and magnetic fields induced by vortices and acting on ions.

  20. Heart and Reason: A Comparison of John Dewey's "A Common Faith" and His "Religious" Poems

    ERIC Educational Resources Information Center

    Miedema, Siebren

    2010-01-01

    In this article a comparison is drawn between the way in which the pragmatist philosopher and pedagogue John Dewey addressed religious issues and his view on Religious Education in his poetic narratives and in his scholarly writings, especially in his "magnus opus" on religion, "A Common Faith". Do we gain deeper insight into Dewey's view on…

  1. Beckham as Physicist?

    ERIC Educational Resources Information Center

    Ireson, Gren

    2001-01-01

    If football captures the interest of students, it can be used to teach physics. In this case, a Beckham free-kick can be used to introduce concepts such as drag, the Bernoulli principle, Reynolds number, and the Magnus effect by asking the simple question: How does he curve the ball so much? Introduces basic mechanics along the way. (Author/ASK)

  2. [Astrologic and medical manuscript of the 18th Century].

    PubMed

    Kugener, Henri

    2010-01-01

    We present a manuscript from the 18th century, an extract taken from the "Great and the Little Albert" attributed to Albertus Magnus. The linguistic variety in the paper is typical for a text composed in Luxembourg. Added to this text are two incantations and a short cartomancy paper. PMID:20882751

  3. Registration of ‘Zenith' black bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Zenith’ black bean (Phaseolus vulgaris L.) (Reg. no. CV- , PI -), developed by Michigan State University AgBioResearch was released in 2014 as an upright, full-season cultivar with anthracnose [caused by Colletotrichum lindemuthianum (Sacc. et Magnus) Lams.-Scrib] resistance and excellent canning q...

  4. Landing Day Wake Up Song and Greeting

    NASA Video Gallery

    Kate Smith’s rendition of Irving Berlin’s “God Bless America” woke Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandy Magnus and Rex Walheim. But unlike most wakeup s...

  5. Clausius-Clapeyron Equation and Saturation Vapour Pressure: Simple Theory Reconciled with Practice

    ERIC Educational Resources Information Center

    Koutsoyiannis, Demetris

    2012-01-01

    While the Clausius-Clapeyron equation is very important as it determines the saturation vapour pressure, in practice it is replaced by empirical, typically Magnus-type, equations which are more accurate. It is shown that the reduced accuracy reflects an inconsistent assumption that the latent heat of vaporization is constant. Not only is this…

  6. Dr. von Braun Surrenders to U.S. Army

    NASA Technical Reports Server (NTRS)

    1945-01-01

    Dr. Wernher von Braun surrenders to U.S. Army Counterintelligence persornel of the 44th Infantry Division in Ruette, Bavaria on May 2, 1945. Left to right are Charles Stewart, CIC agent; Dr. Herbert Axster; Dieter Huzel; Dr. von Braun (arm in cast); Magnus von Braun (brother); and Hans Lindenberg.

  7. Finishing High School: Alternative Pathways and Dropout Recovery

    ERIC Educational Resources Information Center

    Tyler, John H.; Lofstrom, Magnus

    2009-01-01

    John Tyler and Magnus Lofstrom take a close look at the problems posed when students do not complete high school. The authors begin by discussing the ongoing, sometimes heated, debate over how prevalent the dropout problem is. They note that one important reason for discrepancies in reported dropout rates is whether holders of the General…

  8. STS-111 Expedition Five Crew Training Clip

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The STS-111 Expedition Five Crew begins with training on payload operations. Flight Engineer Peggy Whitson and Mission Specialist Sandy Magnus are shown in Shuttle Remote Manipulator System (SRMS) procedures. Flight Engineer Sergei Treschev gets suited for Neutral Neutral Buoyancy Lab (NBL) training. Virtual Reality lab training is shown with Peggy Whitson. Habitation Equipment and procedures are also presented.

  9. Vortex pair production and decay of a two-dimensional supercurrent by a quantum-field-theory approach

    SciTech Connect

    Iengo, R. |; Jug, G. |

    1995-09-01

    We investigate the phenomenon of the decay of a supercurrent through homogeneous nucleation of vortex-antivortex pairs in a two-dimensional (2D) like superconductor or superfluid by means of a quantum electrodynamic formulation for the decay of the 2D vacuum. The case in which both externally driven current and Magnus force are present is treated exactly, taking the vortex activation energy and its inertial mass as independent parameters. Quantum dissipation is included through the formulation introduced by Caldeira and Leggett. The most relevant consequence of quantum dissipation is the elimination of the threshold for vortex production due to the Magnus force. In the dissipation-dominated case, corresponding formally to the limit of zero intertial mass, an exact formula for the pair production rate is given. If however the inertial mass is strictly zero we find that vortex production is inhibited by a quantum effect related to the Magnus force. The possibility of including vortex pinning is investigated by means of an effective harmonic potential. While an additional term in the vortex activation energy can account for the effect of a finite barrier in the direction perpendicular to the current, pinning along the current depresses the role of the Magnus force in the dissipation-dominated dynamics, except for the above-mentioned quantum effect. A possible description of vortex nucleation due to the combined effects of temperature and externally driven currents is also presented along with an evaluation of the resulting voltage drop.

  10. Noncommuting Momenta of Topological Solitons

    NASA Astrophysics Data System (ADS)

    Watanabe, Haruki; Murayama, Hitoshi

    2014-05-01

    We show that momentum operators of a topological soliton may not commute among themselves when the soliton is associated with the second cohomology H2 of the target space. The commutation relation is proportional to the winding number, taking a constant value within each topological sector. The noncommutativity makes it impossible to specify the momentum of a topological soliton, and induces a Magnus force.

  11. Recent Experiments at the Gottingen Aerodynamic Institute

    NASA Technical Reports Server (NTRS)

    Ackeret, J

    1925-01-01

    This report presents the results of various experiments carried out at the Gottingen Aerodynamic Institute. These include: experiments with Joukowski wing profiles; experiments on an airplane model with a built-in motor and functioning propeller; and the rotating cylinder (Magnus Effect).

  12. Nonadiabatic three-neutrino oscillations in matter

    SciTech Connect

    DOlivo, J.C.; Oteo, J.A.

    1996-07-01

    Oscillations of three neutrinos in matter are analyzed by using the Magnus expansion for the time-evolution operator. We derive a simple expression for the electron-neutrino survival probability which is applied to the examination of the effect of a third neutrino on the nonadiabatic flavor transformations. {copyright} {ital 1996 The American Physical Society.}

  13. The Bernoulli or Coanda Conundrum and Other Classical Demonstration Myths

    NASA Astrophysics Data System (ADS)

    Stille, Dale

    2009-11-01

    Lecture Demonstration professionals have recently taken a closer look at demonstrations that were traditionally labeled ``Bernoulli Demonstrations'' in most textbooks. This examination has shown that in most cases the Coanda Effect, Magnus Effect, and Entrainment may be better explanations for most of these classic demonstrations. A discussion of other similarly classic demonstrations and some of their problems or misconceptions will also be presented.

  14. Chemical, Biochemical, and Genetic Approaches to Arsenic Metabolism" -An overview of arsenic metabolism and toxicity- A series of five papers to appear together in Current Protocols in Toxicology

    EPA Science Inventory

    The toxic properties of arsenic (As) were recognized long before Albertus Magnus in the 13th century prepared its elemental form (Buchanan, 1962). Its use as a poison has played lethal and decisive roles in domestic and dynastic intrigues throughout history (Cullen, 2008). Inorga...

  15. Direct numerical simulation of moderate-Reynolds-number flow past arrays of rotating spheres

    NASA Astrophysics Data System (ADS)

    Zhou, Qiang; Fan, Liang-Shih

    2015-07-01

    Direct numerical simulations with an immersed boundary-lattice Boltzmann method are used to investigate the effects of particle rotation on flows past random arrays of mono-disperse spheres at moderate particle Reynolds numbers. This study is an extension of a previous study of the authors [Q. Zhou and L.-S. Fan, "Direct numerical simulation of low-Reynolds-number flow past arrays of rotating spheres," J. Fluid Mech. 765, 396-423 (2015)] that explored the effects of particle rotation at low particle Reynolds numbers. The results of this study indicate that as the particle Reynolds number increases, the normalized Magnus lift force decreases rapidly when the particle Reynolds number is in the range lower than 50. For the particle Reynolds number greater than 50, the normalized Magnus lift force approaches a constant value that is invariant with solid volume fractions. The proportional dependence of the Magnus lift force on the rotational Reynolds number (based on the angular velocity and the diameter of the spheres) observed at low particle Reynolds numbers does not change in the present study, making the Magnus lift force another possible factor that can significantly affect the overall dynamics of fluid-particle flows other than the drag force. Moreover, it is found that both the normalized drag force and the normalized torque increase with the increase of the particle Reynolds number and the solid volume fraction. Finally, correlations for the drag force, the Magnus lift force, and the torque in random arrays of rotating spheres at arbitrary solids volume fractions, rotational Reynolds numbers, and particle Reynolds numbers are formulated.

  16. Flight dynamics of a spinning projectile descending on a parachute

    SciTech Connect

    Benedetti, G.A.

    1989-02-01

    During the past twenty years Sandia National Laboratories and the US Army have vertically gun launched numerous 155mm and eight-inch diameter flight test projectiles. These projectiles are subsequently recovered using an on-board parachute recovery system which is attached to the forward case structure of the projectile. There have been at least five attempts to describe, through analytical and numerical simulations, the translational and rotational motions of a spinning projectile descending on a parachute. However, none of these investigations have correctly described the large nutational motion of the projectile since all of them overlooked the fundamental mechanism which causes these angular motions. Numerical simulations as well as a closed form analytical solution show conclusively that the Magnus moment is responsible for the large nutational motion of the projectile. That is, when the center of pressure for the Magnus force is aft of the center of mass for the projectile, the Magnus moment causes an unstable (or large) nutational motion which always tends to turn the spinning projectile upside down while it is descending on the parachute. Conversely, when the center of mass for the projectile is aft of the center of pressure for the Magnus force, the Magnus moment stabilizes the nutational motion tending to always point the base of the spinning projectile down. The results of this work are utilized to render projectile parachute recovery systems more reliable and to explain what initially may appear to be strange gyrodynamic behavior of a spinning projectile descending on a parachute. 14 refs., 20 figs.

  17. STS-112 crew walks out of O&C building before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Still waving at spectators, the STS-112 crew heads for the Astrovan that will take them to Launch Pad 39B and Space Shuttle Atlantis. Liftoff is scheduled for 3:46 p.m. EDT. From left are Mission Specialists Fyodor Yurchikhin David Wolf, and Piers Sellers; Pilot Pamela Melroy; Mission Specialist Sandra Magnus; and Commander Jeffrey Ashby. Sellers, Magnus and Yurchikhin are making their first Shuttle flights. STS-112 is the 15th assembly flight to the International Space Station, carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss to the Station.

  18. STS-112 crew after arrival at SLF for launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew pauses for a photo after their arrival at the KSC Shuttle Landing Facility. Standing, left to right, are Mission Specialist Piers Sellers, Pilot Pamela Melroy, Commander Jeffrey Ashby, and Mission Specialists David Wolf, Sandra Magnus and cosmonaut Fyodor Yurchikhin. Sellers, Magnus and Yurchikhin are making their first Shuttle flights. STS-112, aboard Space Shuttle Atlantis, is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. The 11-day mission includes three spacewalks. Launch is scheduled for Oct. 2 between 2 and 6 p.m.

  19. Magnetic bilayer-skyrmions without skyrmion Hall effect

    PubMed Central

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-01-01

    Magnetic skyrmions might be used as information carriers in future advanced memories, logic gates and computing devices. However, there exists an obstacle known as the skyrmion Hall effect (SkHE), that is, the skyrmion trajectories bend away from the driving current direction due to the Magnus force. Consequently, the skyrmions in constricted geometries may be destroyed by touching the sample edges. Here we theoretically propose that the SkHE can be suppressed in the antiferromagnetically exchange-coupled bilayer system, since the Magnus forces in the top and bottom layers are exactly cancelled. We show that such a pair of SkHE-free magnetic skyrmions can be nucleated and be driven by the current-induced torque. Our proposal provides a promising means to move magnetic skyrmions in a perfectly straight trajectory in ultra-dense devices with ultra-fast processing speed. PMID:26782905

  20. Paradoxical pop-ups: Why are they difficult to catch?

    NASA Astrophysics Data System (ADS)

    McBeath, Michael K.; Nathan, Alan M.; Bahill, A. Terry; Baldwin, David G.

    2008-08-01

    Professional baseball players occasionally find it difficult to gracefully approach seemingly routine pop-ups. We describe a set of towering pop-ups with trajectories that exhibit cusps and loops near the apex. For a normal fly ball the horizontal velocity continuously decreases due to drag caused by air resistance. For pop-ups the Magnus force is larger than the drag force. In these cases the horizontal velocity initially decreases like a normal fly ball, but after the apex, the Magnus force accelerates the horizontal motion. We refer to this class of pop-ups as paradoxical because they appear to misinform the typically robust optical control strategies used by fielders and lead to systematic vacillation in running paths, especially when a trajectory terminates near the fielder. Former major league infielders confirm that our model agrees with their experiences.

  1. Description of three new troglobiontic species of Cybaeodes (Araneae, Liocranidae) endemic to the Iberian Peninsula.

    PubMed

    Ribera, Carles; De Mas, Eva

    2015-01-01

    Three new troglobiontic species of the spider genus Cybaeodes Simon endemic to caves in the southeastern Iberian Peninsula are described and illustrated: Cybaeodes indalo sp. n. from Almería, C. dosaguas sp. n. from València and C. magnus sp. n. from Alacant. The new species confirm the presence of Cybaeodes on the Iberian Peninsula and its wide distribution throughout the Western Mediterranean including Algeria, Tunisia, Italy, France, Spain and the islands of Sardinia, Sicily and Mallorca. A record of C. liocraninus (Simon), from an Iberian cave was probably based on misidentified specimens of C. magnus sp. n. C. liocraninus is known only from Algeria and should be removed from lists of the Iberian fauna. In addition, the three new species are clear candidates for protection: they have highly restricted ranges and show a high degree of adaptation to the subterranean environment. PMID:26249078

  2. Burying flowlines and cables in 186-m water

    SciTech Connect

    Cameron, G.

    1983-07-01

    UDI Group Ltd. and British Petroleum Development Ltd. have developed a 30-ton remote controlled seabed vehicle. The vehicle was built with the expressed purpose of burying the 35 km of flowlines for the remote wellheads on the Magnus field in 186-m of water, in order to increase thermal insulation of pipelines and to produce a greater degree of physical protection against damage from fishing gear, etc. During the 1981 trials, it was decided to carry out further development of the system for simultaneous laying and burial of the control umbilicals required for the remote wellhead controls on Magnus. For this work, it was necessary for each control umbilical to be positioned alongside its respective flowline along the route between the wellhead and the platform. At the platform end of the route, the flowlines and umbilicals are densely concentrated, and accuracy is required in the laying and burying of the umbilicals.

  3. Computation of hypersonic laminar viscous flow past spinning sharp and blunt cones at high angle of attack

    NASA Technical Reports Server (NTRS)

    Agarwal, R.; Rakich, J. V.

    1978-01-01

    Computational results, obtained with a parabolic Navier-Stokes marching code, are presented for hypersonic viscous flow past spinning sharp and blunt cones at angle of attack. The code takes into account the asymmetries in the flow field resulting from spinning motion and computes the asymmetric shock shape, crossflow and streamwise shear, heat transfer, crossflow separation, and vortex structure. The Magnus force and moments are also computed. Comparisons are made with other theoretical analyses based on boundary-layer and boundary-region equations, and an anomaly is discovered in the displacement thickness contribution to the Magnus force when compared with boundary-layer results. In addition, a new criterion for defining crossflow separation behind spinning bodies is introduced which generalizes the Moore-Rott-Sears criterion for two-dimensional unsteady separation. A condition which characterizes the onset of separation in the flow field is defined.

  4. Collective Transport Properties of Driven Skyrmions with Random Disorder

    NASA Astrophysics Data System (ADS)

    Reichhardt, C.; Ray, D.; Reichhardt, C. J. Olson

    2015-05-01

    We use particle-based simulations to examine the static and driven collective phases of Skyrmions interacting with random quenched disorder. We show that nondissipative effects due to the Magnus term reduce the depinning threshold and strongly affect the Skyrmion motion and the nature of the dynamic phases. The quenched disorder causes the Hall angle to become drive dependent in the moving Skyrmion phase, while different flow regimes produce distinct signatures in the transport curves. For weak disorder, the Skyrmions form a pinned crystal and depin elastically, while for strong disorder the system forms a pinned amorphous state that depins plastically. At high drives the Skyrmions can dynamically reorder into a moving crystal, with the onset of reordering determined by the strength of the Magnus term.

  5. Magnetic bilayer-skyrmions without skyrmion Hall effect.

    PubMed

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-01-01

    Magnetic skyrmions might be used as information carriers in future advanced memories, logic gates and computing devices. However, there exists an obstacle known as the skyrmion Hall effect (SkHE), that is, the skyrmion trajectories bend away from the driving current direction due to the Magnus force. Consequently, the skyrmions in constricted geometries may be destroyed by touching the sample edges. Here we theoretically propose that the SkHE can be suppressed in the antiferromagnetically exchange-coupled bilayer system, since the Magnus forces in the top and bottom layers are exactly cancelled. We show that such a pair of SkHE-free magnetic skyrmions can be nucleated and be driven by the current-induced torque. Our proposal provides a promising means to move magnetic skyrmions in a perfectly straight trajectory in ultra-dense devices with ultra-fast processing speed. PMID:26782905

  6. Computation of supersonic turbulent flow past a spinning cone

    NASA Technical Reports Server (NTRS)

    Agarwal, R. K.

    1982-01-01

    Computational results are presented for supersonic laminar and turbulent flow past a pointed cone at angle of attack obtained with a parabolic Navier-Stokes marching code. The code takes into account the asymmetries in the flowfield resulting from spinning motion and computes the asymmetric shock shape, crossflow and streamwise shear, heat transfer, crossflow separation, and vortex structure. The Magnus force and moments are also computed. Comparisons are made with other analyses based on boundary-layer equations. For certain laminar flow conditions, an anomaly is discovered in the displacement thickness contribution to the Magnus force when compared with boundary-layer results. For turbulent flow, at small angles of attack, good agreement is obtained with the experimental data and other theoretical results.

  7. Magnetic bilayer-skyrmions without skyrmion Hall effect

    NASA Astrophysics Data System (ADS)

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-01-01

    Magnetic skyrmions might be used as information carriers in future advanced memories, logic gates and computing devices. However, there exists an obstacle known as the skyrmion Hall effect (SkHE), that is, the skyrmion trajectories bend away from the driving current direction due to the Magnus force. Consequently, the skyrmions in constricted geometries may be destroyed by touching the sample edges. Here we theoretically propose that the SkHE can be suppressed in the antiferromagnetically exchange-coupled bilayer system, since the Magnus forces in the top and bottom layers are exactly cancelled. We show that such a pair of SkHE-free magnetic skyrmions can be nucleated and be driven by the current-induced torque. Our proposal provides a promising means to move magnetic skyrmions in a perfectly straight trajectory in ultra-dense devices with ultra-fast processing speed.

  8. Vortex dynamics in self-dual Chern-Simons-Higgs systems

    SciTech Connect

    Kim, Y. ); Lee, K. )

    1994-02-15

    We consider vortex dynamics in self-dual Chern-Simons-Higgs systems. We show that the naive Aharonov-Bohm phase is the inverse of the statistical phase expected from the vortex spin, and that the self-dual configurations of vortices are degenerate in energy but not in angular momentum. We also use the path integral formalism to derive the dual formulation of Chern-Simons-Higgs systems in which vortices appear as charged particles. We argue that in addition to the electromagnetic interaction, there is an additional interaction between vortices, the so-called Magnus force, and that these forces can be put together into a single dual electromagnetic'' interaction. This dual electromagnetic interaction leads to the right statistical phase. We also derive and study the effective action for slowly moving vortices, which contains terms both linear and quadratic in the vortex velocity. We show that vortices can be bounded to each other by the Magnus force.

  9. Exploring unconventional capabilities of holographic tweezers

    NASA Astrophysics Data System (ADS)

    Hernandez, R. J.; Pagliusi, P.; Provenzano, C.; Cipparrone, G.

    2011-06-01

    We report an investigation of manipulation and trapping capabilities of polarization holographic tweezers. A polarization gradient connected with a modulation of the ellipticity shows an optical force related to the polarization of the light that can influence optically isotropic particles. While in the case of birefringent particles an unconventional trapping in circularly polarized fringes is observed. A liquid crystal emulsion has been adopted to investigate the capabilities of the holographic tweezers. The unusual trapping observed for rotating bipolar nematic droplets has suggested the involvement of the lift hydrodynamic force responsible of the Magnus effect, originating from the peculiar optical force field. We show that the Magnus force which is ignored in the common approach can contribute to unconventional optohydrodynamic trapping and manipulation.

  10. The Fos expression in rat brain following electrical stimulation of dura mater surrounding the superior sagittal sinus changed with the pre-treatment of rizatriptan benzoate.

    PubMed

    Wang, Xiaolin; Yu, Shengyuan; Dong, Zhao; Jiang, Lei

    2011-01-01

    Fos expression in the brain was systematically investigated by means of immunohistochemical staining after electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious rats. Fos-like immunoreactive neurons are distributed mainly in the upper cervical spinal cord, spinal trigeminal nucleus caudal part, raphe magnus nucleus, periaqueductal gray, ventromedial hypothalamic nucleus, and mediodorsal thalamus nucleus. With the pre-treatment of intraperitoneal injection of rizatriptan benzoate, the number of Fos-like immunoreactive neurons decreased in the spinal trigeminal nucleus caudal part and raphe magnus nucleus, increased in the periaqueductal gray, and remained unchanged in the ventromedial hypothalamic nucleus and mediodorsal thalamus nucleus. These results provide morphological evidence that the nuclei described above are involved in the development and maintenance of the trigeminovascular headache. PMID:20934408

  11. Individual cells in the raphe nuclei of the medulla oblongata in rat that contain immunoreactivities for both serotonin and enkephalin project to the spinal cord.

    PubMed

    Millhorn, D E; Hökfelt, T; Verhofstad, A A; Terenius, L

    1989-01-01

    The ventral medulla oblongata of rats was analyzed with a double-labelling immunofluorescence technique using guinea pig antibodies directed against serotonin (5-HT) and rabbit antisera directed against enkephalin (ENK). Numerous cells in the region of nucleus raphe obscurus, nucleus raphe pallidus and nucleus raphe magnus showed immunostaining for either 5-HT or ENK. A substantial number of cells showed positive immunostaining for both 5-HT and ENK. 5-HT/ENK double-labelled cells were most frequently encountered in an area that extended from the rostral aspect of the inferior olivary nucleus to the pontomedullary border. This region corresponds anatomically to nucleus raphe magnus/nucleus paragigantocellularis. In addition, a number of the 5-HT/ENK-containing cells were retrogradely labelled with Fluoro-Gold dye that had been injected into the thoracic spinal cord several days prior to perfusion. Schematic drawings showing the anatomical distribution of 5-HT/ENK colocalization are provided. PMID:2744110

  12. Immunohistochemical evidence for colocalization of gamma-aminobutyric acid and serotonin in neurons of the ventral medulla oblongata projecting to the spinal cord.

    PubMed

    Millhorn, D E; Hökfelt, T; Seroogy, K; Oertel, W; Verhofstad, A A; Wu, J Y

    1987-04-28

    Fluorescence immunohistochemistry was used to analyze the medulla oblongata of colchicine-treated rats that had been incubated with guinea pig antibodies to serotonin (5-HT) and either rabbit or sheep antibodies to glutamic acid decarboxylase (GAD). Numerous cells in the rostral ventrolateral medulla in the region of nucleus raphe magnus were immunostained for either 5-HT or GAD. A substantial number of neurons showed positive immunoreactivity for both substances, and were most frequently observed in the lateral aspect of nucleus raphe magnus. In addition, a number of the 5-HT/GAD-containing neurons were retrogradely labelled with Fast blue dye that had been injected into the thoracic spinal cord. This work provides evidence for colocalization of the classical neurotransmitters 5-HT and GABA in single cells of the ventral medulla oblongata, some of which project to the spinal cord. PMID:3555707

  13. STS-112 takes part in post-landing briefing for the media

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew takes part in a post-landing briefing for the media. From left are Mission Specialists David Wolf, Sandra Magnus, responding to a question, and Piers Sellers. Mission STS-112 was the 15th assembly flight to the International Space Station, installing the S1 truss. The landing was the 60th at KSC in the history of the Shuttle program.

  14. STS-112 Crew Portrait

    NASA Technical Reports Server (NTRS)

    2002-01-01

    JOHNSON SPACE CENTER, HOUSTON, TEXAS -- (STS112-S-002) These five astronauts and cosmonaut take a break from training to pose for the STS-112 crew portrait. Astronauts Pamela A. Melroy and Jeffrey S. Ashby, pilot and commander respectively, are in the cen ter of the photo. The mission specialists are from left to right, astronauts Sandra H. Magnus, David A. Wolf and Piers J. Sellers, and cosmonaut Fyodor Yurchikhin, who represents Rosaviakosmos.

  15. Niche partitioning in a sympatric cryptic species complex.

    PubMed

    Scriven, Jessica J; Whitehorn, Penelope R; Goulson, Dave; Tinsley, Matthew C

    2016-03-01

    Competition theory states that multiple species should not be able to occupy the same niche indefinitely. Morphologically, similar species are expected to be ecologically alike and exhibit little niche differentiation, which makes it difficult to explain the co-occurrence of cryptic species. Here, we investigated interspecific niche differentiation within a complex of cryptic bumblebee species that co-occur extensively in the United Kingdom. We compared the interspecific variation along different niche dimensions, to determine how they partition a niche to avoid competitive exclusion. We studied the species B. cryptarum, B. lucorum, and B. magnus at a single location in the northwest of Scotland throughout the flight season. Using mitochondrial DNA for species identification, we investigated differences in phenology, response to weather variables and forage use. We also estimated niche region and niche overlap between different castes of the three species. Our results show varying levels of niche partitioning between the bumblebee species along three niche dimensions. The species had contrasting phenologies: The phenology of B. magnus was delayed relative to the other two species, while B. cryptarum had a relatively extended phenology, with workers and males more common than B. lucorum early and late in the season. We found divergent thermal specialisation: In contrast to B. cryptarum and B. magnus, B. lucorum worker activity was skewed toward warmer, sunnier conditions, leading to interspecific temporal variation. Furthermore, the three species differentially exploited the available forage plants: In particular, unlike the other two species, B. magnus fed predominantly on species of heather. The results suggest that ecological divergence in different niche dimensions and spatio-temporal heterogeneity in the environment may contribute to the persistence of cryptic species in sympatry. Furthermore, our study suggests that cryptic species provide distinct

  16. The Burnside problem and related topics

    NASA Astrophysics Data System (ADS)

    Adian, Sergei I.

    2011-01-01

    This paper gives a survey of results related to the famous Burnside problem on periodic groups. A negative solution of this problem was first published in joint papers of P.S. Novikov and the author in 1968. The theory of transformations of words in free periodic groups that was created in these papers and its various modifications give a very productive approach to the investigation of hard problems in group theory. In 1950 the Burnside problem gave rise to another problem on finite periodic groups, formulated by Magnus and called by him the restricted Burnside problem. Here it is called the Burnside-Magnus problem. In the Burnside problem the question of local finiteness of periodic groups of a given exponent was posed, but the Burnside-Magnus problem is the question of the existence of a maximal finite periodic group R(m,n) of a fixed period n with a given number m of generators. These problems complement each other. The publication in a joint paper by the author and Razborov in 1987 of the first effective proof of the well-known result of Kostrikin on the existence of a maximal group R(m,n) for any prime n, together with an indication of primitive recursive upper bounds for the orders of these groups, stimulated investigations of the Burnside-Magnus problem as well. Very soon other effective proofs appeared, and then Zel'manov extended Kostrikin's result to the case when n is any power of a prime number. These results are discussed in the last section of this paper. Bibliography: 105 titles.

  17. [Book review] The Sound Approach to Birding: A Guide to Understanding Bird Sound. --Mark Constantine and The Sound Approach. 2006. Poole, Dorset, United Kingdom.192 pp. + 2 CDs

    USGS Publications Warehouse

    Robbins, C.S.

    2007-01-01

    What is the ?Sound Approach?? It is a trio of enthusiastic bird-sound recordists?analysts (Arnoud B. van den Berg, Mark Constantine, and Magnus Robb) who, with friends, traveled to 42 countries in a massive effort to record all the songs and calls of the birds of the Western Palearctic. The recordings in this guide are selected from the 30,000 or so recorded digitally with stereo microphones by the authors since the year 2000.

  18. Quantum depinning of flux lines from columnar defects

    SciTech Connect

    Chudnovsky, E.M. ); Ferrera, A.; Vilenkin, A. )

    1995-01-01

    The depinning of a flux line from a columnar defect is studied within the path-integral approach. Instantons of the quantum field theory in 1+1 dimensions are computed for the flux line whose dynamics is dominated by the Magnus force. The universal temperature dependence of the decay rate in the proximity of the critical current is obtained. This problem provides an example of macroscopic quantum tunneling, which is accessible to the direct comparison between theory and experiment.

  19. Earth matter effect on active-sterile neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Acero, Mario A.; Aguilar-Arevalo, Alexis A.; D'Olivo, J. C.

    2011-08-01

    Oscillations between active and sterile neutrinos remain as an open possibility to explain some experimental observations. In a four-neutrino mixing scheme, we use the Magnus expansion of the evolution operator to study the evolution of neutrino flavor amplitudes within the Earth. We apply this formalism to calculate the transition probabilities from active to sterile neutrinos taking into account the matter effect for a varying terrestrial density.

  20. Physical optics in a uniform gravitational field

    NASA Astrophysics Data System (ADS)

    Hacyan, Shahen

    2012-01-01

    The motion of a (quasi-)plane wave in a uniform gravitational field is studied. It is shown that the energy of an elliptically polarized wave does not propagate along a geodesic, but in a direction that is rotated with respect to the gravitational force. The similarity with the walk-off effect in anisotropic crystals or the optical Magnus effect in inhomogeneous media is pointed out.

  1. Removing Boundary Layer by Suction

    NASA Technical Reports Server (NTRS)

    Ackeret, J

    1927-01-01

    Through the utilization of the "Magnus effect" on the Flettner rotor ship, the attention of the public has been directed to the underlying physical principle. It has been found that the Prandtl boundary-layer theory furnishes a satisfactory explanation of the observed phenomena. The present article deals with the prevention of this separation or detachment of the flow by drawing the boundary layer into the inside of a body through a slot or slots in its surface.

  2. The algebraic criteria for the stability of control systems

    NASA Technical Reports Server (NTRS)

    Cremer, H.; Effertz, F. H.

    1986-01-01

    This paper critically examines the standard algebraic criteria for the stability of linear control systems and their proofs, reveals important previously unnoticed connections, and presents new representations. Algebraic stability criteria have also acquired significance for stability studies of non-linear differential equation systems by the Krylov-Bogoljubov-Magnus Method, and allow realization conditions to be determined for classes of broken rational functions as frequency characteristics of electrical network.

  3. Quantum depinning in layered superconductors with defects produced by irradiation

    SciTech Connect

    Bulaevskii, L.N.; Larkin, A.I.; Maley, M.P.; Vinokur, V.M.

    1995-10-01

    We consider Magnus force vortex dynamics in superclean superconductors and calculate the quantum tunneling rate of the pancake vortex creep from the pinning cites in the nondissipative limit. The consideration is based on the exact representation of the one-particle wave functions in the magnetic and electric fields. The obtained results are compared to the experimental data and the possibility of the observation of the discrete structure of the pinned pancake energy levels is discussed.

  4. Dynamics of skyrmions in chiral magnets: Dynamic phase transitions and equation of motion

    SciTech Connect

    Lin, Shi-Zeng Reichhardt, Charles; Batista, Cristian D.; Saxena, Avadh

    2014-05-07

    We study the dynamics of skyrmions in a metallic chiral magnet. First, we show that skyrmions can be created dynamically by destabilizing the ferromagnetic background state through a spin polarized current. We then treat skyrmions as rigid particles and derive the corresponding equation of motion. The dynamics of skyrmions is dominated by the Magnus force, which accounts for the weak pinning of skyrmions observed in experiments. Finally, we discuss the quantum motion of skyrmions.

  5. Models of Structure of the Envelope of Influenza Virus*†

    PubMed Central

    Tiffany, John M.; Blough, Herbert A.

    1970-01-01

    Possible models of the structure of the influenza virus envelope are considered in terms of the known chemical composition. Models incorporating lipid in the form of a bimolecular leaflet are shown to be unlikely on geometrical grounds. A model having „inverted toadstool” protein units separated by spherical lipid micelles is favored, and is capable of explaining the appearance of the virus in the electron microscope and differences between normal and incomplete (von Magnus) forms of the virus. Images PMID:5266149

  6. Fos and serotonin immunoreactivity in the raphe nuclei of the cat during carbachol-induced active sleep: a double-labeling study.

    PubMed

    Yamuy, J; Sampogna, S; López-Rodríguez, F; Luppi, P H; Morales, F R; Chase, M H

    1995-07-01

    The microinjection of carbachol into the nucleus pontis oralis produces a state which is polygraphically and behaviorally similar to active sleep (rapid eye movement sleep). In the present study, using double-labeling techniques for serotonin and the protein product of c-fos (Fos), we sought to examine whether immunocytochemically identified serotonergic neurons of the raphe nuclei of the cat were activated, as indicated by their expression of c-fos, during this pharmacologically-induced behavioral state (active sleep-carbachol). Compared with control cats, which were injected with saline, active sleep-carbachol cats exhibited a significantly greater number of c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus. Whereas most of the c-fos-expressing neurons in the raphe dorsalis were small, those in the raphe magnus were medium-sized and in the raphe pallidus they were small and medium-sized. The mean number of serotonergic neurons that expressed c-fos (i.e. double-labeled cells) was similar in control and active sleep-carbachol cats. These data indicate that there is an increased number of non-serotonergic, c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus during the carbachol-induced state.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7477901

  7. Ratchet Effects, Negative Mobility, and Phase Locking for Skyrmions on Periodic Substrates

    NASA Astrophysics Data System (ADS)

    Reichhardt, Charles; Ray, Dipanjan; Olson Reichhardt, Cynthia

    We examine the dynamics of skyrmions interacting with 1D and 2D periodic substrates in the presence of dc and ac drives. We find that the Magnus term strongly affects the skyrmion dynamics and that new kinds of phenomena can occur which are absent for overdamped ac and dc driven particles interacting with similar substrates. We show that it is possible to realize a Magnus induced ratchet for skyrmions interacting with an asymmetric potential, where the application of an ac drive can produce quantized dc motion of the skyrmions even when the ac force is perpendicular to the substrate asymmetry direction. For symmetric substrates it is also possible to achieve a negative mobility effect where the net skyrmion motion runs counter to an applied dc drive. Here, as a function of increasing dc drive, the velocity-force curves show a series of locking phases that have different features from the classic Shapiro steps found in overdamped systems. In the phase locking and ratcheting states, the skyrmions undergo intricate 2D orbits induced by the Magnus term.

  8. STS-112 Crew Training Clip

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Footage shows the crew of STS-112 (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Piers Sellers, Sandra Magnus, and Fyodor Yurchikhin, Mission Specialists) during several parts of their training. The video is arranged into short segments. In 'Topside Activities at the NBL', Wolf and Sellers are fitted with EVA suits for pool training. 'Pre-Launch Bailout Training in CCT II' shows all six crew members exiting from the hatch on a model of a shuttle orbiter cockpit. 'EVA Training in the VR Lab' shows a crew member training with a virtual reality simulator, interspersed with footage of Magnus, and Wolf with Melroy, at monitors. There is a 'Crew Photo Session', and 'Pam Melroy and Sandy Magnus at the SES Dome' also features a virtual reality simulator. The final two segments of the video involve hands-on training. 'Post Landing Egress at the FFT' shows the crew suiting up into their flight suits, and being raised on a harness, to practice rapelling from the cockpit hatch. 'EVA Prep and Post at the ISS Airlock' shows the crew assembling an empty EVA suit onboard a model of a module. The crew tests oxygen masks, and Sellers is shown on an exercise bicycle with an oxygen mask, with his heart rate monitored (not shown).

  9. STS-112 Crew Training Clip

    NASA Astrophysics Data System (ADS)

    2002-09-01

    Footage shows the crew of STS-112 (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Piers Sellers, Sandra Magnus, and Fyodor Yurchikhin, Mission Specialists) during several parts of their training. The video is arranged into short segments. In 'Topside Activities at the NBL', Wolf and Sellers are fitted with EVA suits for pool training. 'Pre-Launch Bailout Training in CCT II' shows all six crew members exiting from the hatch on a model of a shuttle orbiter cockpit. 'EVA Training in the VR Lab' shows a crew member training with a virtual reality simulator, interspersed with footage of Magnus, and Wolf with Melroy, at monitors. There is a 'Crew Photo Session', and 'Pam Melroy and Sandy Magnus at the SES Dome' also features a virtual reality simulator. The final two segments of the video involve hands-on training. 'Post Landing Egress at the FFT' shows the crew suiting up into their flight suits, and being raised on a harness, to practice rapelling from the cockpit hatch. 'EVA Prep and Post at the ISS Airlock' shows the crew assembling an empty EVA suit onboard a model of a module. The crew tests oxygen masks, and Sellers is shown on an exercise bicycle with an oxygen mask, with his heart rate monitored (not shown).

  10. Two new species of the deep-sea genus Parameiropsis (Copepoda: Harpacticoida) from the eastern central Pacific.

    PubMed

    Cho, Dae Hyun; Wi, Jin Hee; Suh, Hae-Lip

    2016-01-01

    Two new species of Parameiropsis are herein described that were identified from the Korean Deep Ocean Study (KODOS) in the Clarion-Clipperton Fracture Zone, located in the eastern central Pacific. Parameiropsis kodosensis n. sp. is similar to P. magnus Itô, 1983 in two key respects: the presence of a distal seta on the syncoxa of the maxilliped, and the general features of its swimming legs. However, P. kodosensis can be differentiated from P. magnus by a higher length-to-width ratio of the caudal ramus (2.5:1 and 1:1 respectively), the setal number on the exp-3 of P1, and the exp and benp of P5 are separated in P. kodosensis, while they are fused in P. magnus. Parameiropsis tetraspinosa n. sp. resembles P. peruanus Becker, 1974 in the absence of a fused seta in the outermost spine on the endopod of antenna and the general features of the swimming legs. However, P. tetraspinosa can be distinguished from P. peruanus by a higher length-to-width ratio of the caudal ramus (3.9:1 and 2.3:1 respectively), the presence of a distal seta on the syncoxa of the maxilliped, and by its medially fused P5. In this study full descriptions and a comparison with previously described species are provided. Additionally, a key to females of Parameiropsis species is given. PMID:27395690

  11. Evolution of the Dynamic Symptoms Model.

    PubMed

    Brant, Jeannine M; Dudley, William N; Beck, Susan; Miaskowski, Christine

    2016-09-01

    Theories and conceptual models can be thought of as broad nets that attempt to rationalize, explain, and master a phenomenon within clinical nursing and interdisciplinary care. They can be used to guide a review of the literature and to formulate and organize research variables and relationships. Gaps in the literature can be identified and opportunities for additional research revealed (Fawcett, 2005). A variety of symptom models or theories exist, including the Theory of Symptom Management (Dodd et al., 2001), Theory of Unpleasant Symptoms (Lenz, Pugh, Milligan, Gift, & Suppe, 1997), Symptoms Experience Model (Armstrong, 2003), and Symptom Experiences in Time Theory (Henly, Kallas, Klatt, & Swenson, 2003). Most recently, the National Institute of Nursing Research identified a new National Institutes of Health Symptom Science Model to guide symptom science research (Cashion & Grady, 2015).
. PMID:27541557

  12. Quantized transport for a skyrmion moving on a two-dimensional periodic substrate

    NASA Astrophysics Data System (ADS)

    Reichhardt, C.; Ray, D.; Reichhardt, C. J. Olson

    2015-03-01

    We examine the dynamics of a skyrmion moving over a two-dimensional periodic substrate utilizing simulations of a particle-based skyrmion model. We specifically examine the role of the nondissipative Magnus term on the driven motion and the resulting skyrmion velocity-force curves. In the overdamped limit, there is a depinning transition into a sliding state in which the skyrmion moves in the same direction as the external drive. When there is a finite Magnus component in the equation of motion, a skyrmion in the absence of a substrate moves at an angle with respect to the direction of the external driving force. When a periodic substrate is added, the direction of motion or Hall angle of the skyrmion is dependent on the amplitude of the external drive, only approaching the substrate-free limit for higher drives. Due to the underlying symmetry of the substrate the direction of skyrmion motion does not change continuously as a function of drive, but rather forms a series of discrete steps corresponding to integer or rational ratios of the velocity components perpendicular ( ) and parallel ( ) to the external drive direction: / =n /m , where n and m are integers. The skyrmion passes through a series of directional locking phases in which the motion is locked to certain symmetry directions of the substrate for fixed intervals of the drive amplitude. Within a given directionally locked phase, the Hall angle remains constant and the skyrmion moves in an orderly fashion through the sample. Signatures of the transitions into and out of these locked phases take the form of pronounced cusps in the skyrmion velocity versus force curves, as well as regions of negative differential mobility in which the net skyrmion velocity decreases with increasing external driving force. The number of steps in the transport curve increases when the relative strength of the Magnus term is increased. We also observe an overshoot phenomena in the directional locking

  13. Yeast biogeography and the effects of species recognition approaches: the case study of widespread basidiomycetous species from birch forests in Russia.

    PubMed

    Yurkov, Andrey; Inácio, João; Chernov, Ivan Yu; Fonseca, Álvaro

    2015-04-01

    Understanding diversity and distribution patterns of fungi, including yeasts, ultimately depends on accuracy of species recognition. However, different approaches to yeast species recognition often result in different entities or operational taxonomic units. We studied the effects of using different yeast species recognition approaches, namely morphological species recognition (MSR) and phylogenetic species recognition (PSR), on the distribution patterns of widespread basidiomycetous yeasts. Hence, we have revised a collection of yeast fungi isolated from spatially remote birch forests in the Moscow Region and Western Siberia with molecular typing and identification tools. PCR fingerprinting and rDNA sequencing analyses of strains of nine species previously identified on the basis of morphological and physiological tests (MSR) yielded 21 phylogenetic species (PSR), including three currently undescribed taxa. The number of distinct phylogenetic species comprised within a single morphospecies ranged from one to seven. A total of ten species were found in both regions, whereas the distribution of 11 yeasts was restricted to a single region only. Both geographical region and type of substrate (plant or soil) influence yeast distribution. Cryptococcus wieringae, C. victoriae, C. magnus, and Leucosporidium scottii were frequently found on plant substrates, whereas C. terricola and C. podzolicus were associated to soil substrates. Occurrence of C. magnus, C. albidus and Sporobolomyces roseus was found to depend on the geographical region. Microsatellite-PCR fingerprinting, MSP-PCR, applied to studying yeast intraspecific variability revealed three different types of distribution: (a) variability that depends on geographical factors (Curvibasidium cygneicollum, C. podzolicus, C. victoriae), (b) genetic identity irrespectively of the region of isolation (Rhodotorula pinicola, C. terricola), and (c) high degree of genetic variability that did not correlate with region of

  14. Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories

    SciTech Connect

    Sharbaugh, R.C.

    1992-03-23

    Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.

  15. Testing the Accuracy of a Projectile Motion Apparatus

    NASA Astrophysics Data System (ADS)

    Henderson, Bret; Martell, Eric

    2013-03-01

    The purpose of this research is to predict where a ball would land given initial velocity, angular velocity, and atmospheric conditions. A spinning spherical object flying through air is affected by gravity, quadratic drag forces, and the Magnus force. Mathematica was used to numerically solve predictions for the equations of motion. These predictions were compared with experimental data gathered by launching tennis balls, baseballs, and/or soccer balls from a machine we designed to propel the balls with a pre-determined initial velocity and initial angular velocity.

  16. Kato expansion in quantum canonical perturbation theory

    NASA Astrophysics Data System (ADS)

    Nikolaev, Andrey

    2016-06-01

    This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson's ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.

  17. Dynamics of two-dimensional vortex pairs in a spatially varying potential

    SciTech Connect

    Lee, H.H. ); Gunn, J.M.F. )

    1992-10-01

    We consider the dynamics of vortices in a superfluid {sup 4}He film flowing over a substrate at zero temperature. The vortex trajectories are assumed to be governed by the Magnus-force equation with the effect of the substrate incorporated via the gradient of a potential. We use an equivalent Hamiltonian formulation to show that two vortices in a slowly varying potential can exhibit stochastic behavior. In this regard, there are differences between the cases of two vortices of the same sign and those of the opposite sign, the latter becoming stochastic more readily.

  18. Hydrodynamic Aspects of the Toms Effect

    NASA Astrophysics Data System (ADS)

    Strel‧nikova, S. A.; Tkachenko, G. V.; Uryukov, B. A.

    2015-11-01

    The physicomathematical model of migration of polymers in a liquid turbulent flow in a pipe is based on a comparison of forces transverse to the motion of the mainstream flow: the Saffman, Magnus, and turbophoresis forces. It has been shown that the polymer particles are grouped near a certain boundary within the limits of the boundary layer. On this basis, the authors have made assumptions on the mechanism of suppression of turbulent pulsations and decrease in the viscous friction near the wall, which makes up the Toms effect. The proposed model satisfies, at least, qualitatively, various actually observed manifestations of the effect.

  19. Improving the In-Medium Similarity Renormalization Group via approximate inclusion of three-body effects

    NASA Astrophysics Data System (ADS)

    Morris, Titus; Bogner, Scott

    2015-10-01

    The In-Medium Similarity Renormalization Group (IM-SRG) has been applied successfully not only to several closed shell finite nuclei, but has recently been used to produce effective shell model interactions that are competitive with phenomenological interactions in the SD shell. A recent alternative method for solving of the IM-SRG equations, called the Magnus expansion, not only provides a computationally feasible route to producing observables, but also allows for approximate handling of induced three-body forces. Promising results for several systems, including finite nuclei, will be presented and discussed.

  20. Dynamics of bubbles in a two-component Bose-Einstein condensate

    NASA Astrophysics Data System (ADS)

    Sasaki, Kazuki; Suzuki, Naoya; Saito, Hiroki

    2011-03-01

    The dynamics of a phase-separated two-component Bose-Einstein condensate are investigated, in which a bubble of one component moves through the other component. Numerical simulations of the Gross-Pitaevskii equation reveal a variety of dynamics associated with the creation of quantized vortices. In two dimensions, a circular bubble deforms into an ellipse and splits into fragments with vortices, which undergo the Magnus effect. The Bénard-von Kármán vortex street is also generated. In three dimensions, a spherical bubble deforms into toruses with vortex rings. When two rings are formed, they exhibit leapfrogging dynamics.

  1. STS-112 crew in front of Launch Pad 39B before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - Members of the STS-112 crew pose in front of Launch Pad 39B during a tour of Kennedy Space Center prior to launch. From left, they are Mission Specialist Sandra H. Magnus, Commander Jeffrey S. Ashby, Pilot Pamela Ann Melroy, a nd Mission Specialists David A. Wolf, Fyodor N. Yurchikhin of the Russian Space Agency, and Piers J. Sellers. The launch of Space Shuttle Atlantis was postponed today to no earlier than Thursday, Oct. 3, while weather forecasters and the mission managemen t team assess the possible effect Hurricane Lili may have on the Mission Control Center located at the Lyndon B. Johnson Space Center in Houston, Texas.

  2. Force balance on two-dimensional superconductors with a single moving vortex

    NASA Astrophysics Data System (ADS)

    Chung, Chun Kit; Arahata, Emiko; Kato, Yusuke

    2014-03-01

    We study forces on two-dimensional superconductors with a single moving vortex based on a recent fully self-consistent calculation of DC conductivity in an s-wave superconductor (E. Arahata and Y. Kato, arXiv:1310.0566). By considering momentum balance of the whole liquid, we attempt to identify various contributions to the total transverse force on the vortex. This provides an estimation of the effective Magnus force based on the quasiclassical theory generalized by Kita [T. Kita, Phys. Rev. B, 64, 054503 (2001)], which allows for the Hall effect in vortex states.

  3. Dynamics of bubbles in a two-component Bose-Einstein condensate

    SciTech Connect

    Sasaki, Kazuki; Suzuki, Naoya; Saito, Hiroki

    2011-03-15

    The dynamics of a phase-separated two-component Bose-Einstein condensate are investigated, in which a bubble of one component moves through the other component. Numerical simulations of the Gross-Pitaevskii equation reveal a variety of dynamics associated with the creation of quantized vortices. In two dimensions, a circular bubble deforms into an ellipse and splits into fragments with vortices, which undergo the Magnus effect. The Benard-von Karman vortex street is also generated. In three dimensions, a spherical bubble deforms into toruses with vortex rings. When two rings are formed, they exhibit leapfrogging dynamics.

  4. Effects of time ordering in quantum nonlinear optics

    NASA Astrophysics Data System (ADS)

    Quesada, Nicolás; Sipe, J. E.

    2014-12-01

    We study time-ordering corrections to the description of spontaneous parametric down-conversion (SPDC), four-wave mixing (SFWM), and frequency conversion using the Magnus expansion. Analytic approximations to the evolution operator that are unitary are obtained. They are Gaussian preserving, and allow us to understand order-by-order the effects of time ordering. We show that the corrections due to time ordering vanish exactly if the phase-matching function is sufficiently broad. The calculation of the effects of time ordering on the joint spectral amplitude of the photons generated in SPDC and SFWM are reduced to quadrature.

  5. STS-112 Flight Day 7 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On this seventh day of STS-112 mission members of the crew (Commander Jeff Ashby; Pilot Pam Melroy; Mission Specialist Sandy Magnus, Piers Sellers, Dave Wolf, and Fyodor Yurchikhin) along with the Expedition Five crew (Commander Valery Korzun; Flight Engineer Peggy Whitson, and Sergei Treschev) are seen answering questions during the mission's press interview and photo opportunity. They answered various questions regarding the mission's objectives, the onboard science experiments, the extravehicular activities (EVAs) and the effects of living in space. Shots of the test deployment of the S1 truss radiator and Canadarm rotor joint are also shown.

  6. Skyrmionic spin Seebeck effect via dissipative thermomagnonic torques

    NASA Astrophysics Data System (ADS)

    Kovalev, Alexey A.

    2014-06-01

    We derive thermomagnonic torque and its "β-type" dissipative correction from the stochastic Landau-Lifshitz-Gilbert equation. The β-type dissipative correction describes viscous coupling between magnetic dynamics and magnonic current and it stems from spin mistracking of the magnetic order. We show that thermomagnonic torque is important for describing temperature gradient induced motion of skyrmions in helical magnets while dissipative correction plays an essential role in generating transverse Magnus force. We propose to detect such skyrmionic motion by employing the transverse spin Seebeck effect geometry.

  7. Second-order shaped pulsed for solid-state quantum computation

    SciTech Connect

    Sengupta, Pinaki

    2008-01-01

    We present the construction and detailed analysis of highly optimized self-refocusing pulse shapes for several rotation angles. We characterize the constructed pulses by the coefficients appearing in the Magnus expansion up to second order. This allows a semianalytical analysis of the performance of the constructed shapes in sequences and composite pulses by computing the corresponding leading-order error operators. Higher orders can be analyzed with the numerical technique suggested by us previously. We illustrate the technique by analyzing several composite pulses designed to protect against pulse amplitude errors, and on decoupling sequences for potentially long chains of qubits with on-site and nearest-neighbor couplings.

  8. Unfolding of Vortices into Topological Stripes in a Multiferroic Material

    NASA Astrophysics Data System (ADS)

    Wang, X.; Mostovoy, M.; Han, M. G.; Horibe, Y.; Aoki, T.; Zhu, Y.; Cheong, S.-W.

    2014-06-01

    Multiferroic hexagonal RMnO3 (R =rare earths) crystals exhibit dense networks of vortex lines at which six domain walls merge. While the domain walls can be readily moved with an applied electric field, the vortex cores so far have been impossible to control. Our experiments demonstrate that shear strain induces a Magnus-type force pulling vortices and antivortices in opposite directions and unfolding them into a topological stripe domain state. We discuss the analogy between this effect and the current-driven dynamics of vortices in superconductors and superfluids.

  9. STS-112 Pilot Melroy inspects cables prior to launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - STS-112 Pilot Pamela Ann Melroy (left) conducts a last-minute inspection of some cables inside Space Shuttle Atlantis at Launch Pad 39B prior to the launch of her mission. The STS-112 crew also includes Commander Jeffrey S. Ashby and Mission Specialists David A. Wolf, Sandra H. Magnus, Piers J. Sellers, and Fyodor N. Yurchikhin of the Russian Space Agency. Launch of the mission was postponed today to no earlier than Thursday, Oct. 3, while weather forecasters and the mission management team assess the possible effect Hurricane Lili may have on the Mission Control Center located at the Lyndon B. Johnson Space Center in Houston, Texas.

  10. Survival of Rydberg atoms in intense laser fields and the role of nondipole effects

    NASA Astrophysics Data System (ADS)

    Klaiber, Michael; Dimitrovski, Darko

    2015-02-01

    We consider the interaction of Rydberg atoms with strong infrared laser pulses using an approach based on the Magnus expansion of the time evolution operator. First-order corrections beyond the electric dipole approximation are also included in the theory. We illustrate the dynamics of the interaction at the parameters of the experiment [Eichmann et al., Phys. Rev. Lett. 110, 203002 (2013), 10.1103/PhysRevLett.110.203002]. It emerges that the depletion of Rydberg atoms in this regime comes predominantly from the nondipole effects.

  11. [Arthur Kronfeld (1886-1941)--a psychiatrist in the service of psychotherapy].

    PubMed

    Schröder, C

    1986-07-01

    The psychotherapeutic life-work of psychiatrist Arthur Kronfeld has almost fallen into oblivion. Against the background of the 100th anniversary of his birth the author traces Kronfeld's psychotherapeutic career, pointing out his activity at the Berliner "Institute of Sexual Research" under Magnus Hirschfeld, and his psychotherapeutic concept--the psychagogic guidance of the patient--and its connection with the individual psychology of Alfred Adler. Kronfeld translated his theoretical positions into activities directed towards socialization and the teachability of psychotherapy which are still worthy of note by those engaged in the field. PMID:3532156

  12. Non-linear meteor trails

    NASA Astrophysics Data System (ADS)

    Beech, Martin

    1988-08-01

    In this essay an attempt is made to not only review but reopen the debate on nonlinear meteor trails. On the basis of data culled from various, now historical, sources it is found that approximately one in every two hundred of the visual meteors is likely to show a nonlinear trail, and that of such trails about 60 percent will be continuously curved and 40 percent sinusoidal. It is suggested that two mechanisms may explain the various trail types: the continuously curved trails being a manifestation of the classical Magnus effect, and the sinusoidal trails resulting from torque-free precession.

  13. The Mass of a Spin Vortex, in a Bose Einstein Condensate

    NASA Astrophysics Data System (ADS)

    Turner, Ari

    2009-03-01

    Ferromagnetic condensates can have both spin-current and charge-current vortices. A moving charge-vortex experiences the Magnus force, perpendicular to its motion, when it moves. This effective ``magnetic field" is so strong that it dominates the inertial term in Newton's law; therefore it is not possible to set a charge-vortex moving at an arbitrary speed relative to the condensate. As we will show, a spin-vortex can move ``inertially" through a condensate and resists acceleration with a mass.

  14. Bioactive Mimetics of Conotoxins and other Venom Peptides

    PubMed Central

    Duggan, Peter J.; Tuck, Kellie L.

    2015-01-01

    Ziconotide (Prialt®), a synthetic version of the peptide ω-conotoxin MVIIA found in the venom of a fish-hunting marine cone snail Conus magnus, is one of very few drugs effective in the treatment of intractable chronic pain. However, its intrathecal mode of delivery and narrow therapeutic window cause complications for patients. This review will summarize progress in the development of small molecule, non-peptidic mimics of Conotoxins and a small number of other venom peptides. This will include a description of how some of the initially designed mimics have been modified to improve their drug-like properties. PMID:26501323

  15. Rigorous Bound on Energy Absorption and Generic Relaxation in Periodically Driven Quantum Systems

    NASA Astrophysics Data System (ADS)

    Mori, Takashi; Kuwahara, Tomotaka; Saito, Keiji

    2016-03-01

    We discuss the universal nature of relaxation in isolated many-body quantum systems subjected to global and strong periodic driving. Our rigorous Floquet analysis shows that the energy of the system remains almost constant up to an exponentially long time in frequency for arbitrary initial states and that an effective Hamiltonian obtained by a truncation of the Floquet-Magnus expansion is a quasiconserved quantity in a long time scale. These two general properties lead to an intriguing classification on the initial stage of relaxation, one of which is similar to the prethermalization phenomenon in nearly integrable systems.

  16. Bioactive Mimetics of Conotoxins and other Venom Peptides.

    PubMed

    Duggan, Peter J; Tuck, Kellie L

    2015-10-01

    Ziconotide (Prialt®), a synthetic version of the peptide ω-conotoxin MVIIA found in the venom of a fish-hunting marine cone snail Conus magnus, is one of very few drugs effective in the treatment of intractable chronic pain. However, its intrathecal mode of delivery and narrow therapeutic window cause complications for patients. This review will summarize progress in the development of small molecule, non-peptidic mimics of Conotoxins and a small number of other venom peptides. This will include a description of how some of the initially designed mimics have been modified to improve their drug-like properties. PMID:26501323

  17. Differentiation of Peptococcus and Peptostreptococcus by gas-liquid chromatography of cellular fatty acids and metabolic products.

    PubMed Central

    Lambert, M A; Armfield, A Y

    1979-01-01

    Gas-liquid chromatographic (GLC) profiles of cellular fatty acids and metabolic products were useful in identifying strains of Peptococcus saccharolyticus, Peptococcus asaccharolyticus, Peptostreptococcus anaerobius, Peptostreptococcus micros, and Streptococcus intermedius. The GLC results supported the recent taxonomic decision to transfer aerotolerant Peptostreptococcus species to the genus Streptococcus. Because inconsistencies in the results prevented our differentiating Peptococcus prevotii. Peptococcus magnus, and Peptococcus variabilis by GLC, additional strains will have to been examined. These GLC techniques are amenable to routine use; however, for interlaboratory results to be meaningful, the classification and nomenclature of the anaerobic gram-positive cocci should be standardized. PMID:528680

  18. A revision of the Chinese Aulacidae (Hymenoptera, Evanioidea)

    PubMed Central

    Chen, Hua-yan; Turrisi, Giuseppe Fabrizio; Xu, Zai-fu

    2016-01-01

    Abstract The Chinese Aulacidae are revised, keyed and illustrated for the first time. In total twenty-five species are recorded from China, included within two genera Aulacus Jurine, 1807 and Pristaulacus Kieffer, 1900, with five and twenty species respectively. Among the treated species, six are newly described for science: Aulacus magnus sp. n., Pristaulacus calidus sp. n., Pristaulacus centralis sp. n., Pristaulacus fopingi sp. n., Pristaulacus obscurus sp. n., and Pristaulacus pseudoiosephi sp. n. Three species are newly recorded from China: Pristaulacus excisus Turner, 1922, Pristaulacus iosephi Turrisi & Madl, 2013, and Pristaulacus rufobalteatus Cameron, 1907. PMID:27408528

  19. Extent of colocalization of serotonin and GABA in neurons of the ventral medulla oblongata in rat.

    PubMed

    Millhorn, D E; Hökfelt, T; Seroogy, K; Verhofstad, A A

    1988-09-27

    The colocalization of serotonin (5-hydroxytryptamine; 5-HT) and gamma-aminobutyric acid (GABA) in the ventral aspect of the rat medulla oblongata was studied using antibodies directed against 5-HT and GABA. Although 5-HT- and GABA-immunoreactive cell bodies were observed over the entire rostral-caudal extent of the ventral medulla, the colocalization of these two classical neurotransmitters in single cells was, for the most part, limited to a region that corresponds anatomically to nucleus raphe magnus/nucleus paragigantocellularis. Schematic drawings showing the distribution of 5-HT/GABA cell bodies in the ventral medulla are provided. PMID:3066433

  20. ["Different from the others". Kraepelin's assessment of Hirschfeld's educational film. A contribution to the history of psychiatry of the Weimar Republic].

    PubMed

    Weber, M M; Burgmair, W

    1997-01-01

    In 1921 the Medical Court of Honour of the County Brandenburg and Berlin procured an expert opinion by the well-known psychiatrist Emil Kraepelin on the first sex education film "Anders als die Andern". The Berlin sexologist Magnus Hirschfeld had launched the film in 1919 to bring his scientific targets of abolition of section 175 StGB and the liberalization of sexual morality to a greater public. Kraepelin succeeded in banning the film because of its subject being a threat to population policy in post World War I Germany. PMID:9333997

  1. New Staphylinidae (Coleoptera) records with new collection data from New Brunswick, Canada: Omaliinae, Micropeplinae, Phloeocharinae, Olisthaerinae, and Habrocerinae

    PubMed Central

    Webster, Reginald P.; Sweeney, Jon D.; DeMerchant, Ian

    2012-01-01

    Abstract Eleven species of Omaliinae are newly recorded from New Brunswick, bringing the total number of species known from the province to 32 described species. Supporting data are presented for the New Brunswick record of Geodromicus strictus (Fauvel) reported by Majka et al. (2011). Micropeplus browni Campbell, Micropeplus laticollis Mäklin (Micropeplinae), Charyhyphus picipennis (LeConte) (Phloeocharinae), Olisthaerus substriatus (Paykull) (Olisthaerinae), Habrocerus capillaricornis (Gravenhorst), Habrocerus magnus LeConte, and Habrocerus schwarzi Horn (Habrocerinae) are also newly recorded for New Brunswick. These are the first records of the latter four subfamilies from New Brunswick. Collection and bionomic data are presented for each species and discussed. PMID:22577316

  2. Lethal outcome in xanthogranulomatous endometritis.

    PubMed

    Noack, Frank; Briese, Juliane; Stellmacher, Florian; Hornung, Daniela; Horny, Hans-Peter

    2006-05-01

    Xanthogranulomatous inflammation is rare, mainly involving the kidneys, while primary xanthogranulomatous endometritis (XE) is a very unusual finding, histologically characterized by partial or complete replacement of the mucosa by granulation tissue with an abundance of foamy histiocytes, siderophages and multinucleated giant cells. We present the case of a 69-year-old woman with a short history of abdominal pain and a palpable mass in the pouch of Douglas. Dilatation of the cervix drained a pyometra. Histological examination of the curettage rendered the diagnosis of XE. Microbiological studies revealed enterococcus spp. and Peptostreptococcus magnus. Despite antibiotic treatment the patient died of heart failure due to systemic inflammation. Autopsy confirmed the diagnosis of XE with transmural extension into the peritoneal cavity. Such a lethal course of XE is extraordinary. Proposed causes of XE include obstruction, infection and hemorrhage. Demonstration of enterococcus spp. and P. magnus supports the probable significance of bacteria in the development of XE. Because this condition may mimic malignant disease macroscopically and histologically, knowledge of XE is of major importance for both pathologists and gynecologists. PMID:16725016

  3. STS-112 Crew exit O&C building before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew eagerly exit the Operations and Checkout Building for their ride to Launch Pad 39B and the launch scheduled 3:46 p.m. EDT. Leading the way are Pilot Pamela Melroy and Commander Jeffrey Ashby. In the second row are Mission Specialists David Wolf (left) and Sandra Magnus. Behind them are Mission Specialists Fyodor Yurchikhin and Piers Sellers. Sellers, Magnus and Yurchikhin are making their first Shuttle flights. STS-112 is the 15th assembly flight to the International Space Station, carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss to the Station. [Photo courtesy of Scott Andrews

  4. Cycloid motions of grains in a dust plasma

    NASA Astrophysics Data System (ADS)

    Yong-Liang, Zhang; Fan, Feng; Fu-Cheng, Liu; Li-Fang, Dong; Ya-Feng, He

    2016-02-01

    Hypocycloid and epicycloid motions of irregular grains (pine pollen) are observed for the first time in a dust plasma in a two-dimensional (2D) horizontal plane. These cycloid motions can be regarded as a combination of a primary circle and a secondary circle. An inverse Magnus force originating from the spin of the irregular grain gives rise to the primary circle. Radial confinement resulting from the electrostatic force and the ion drag force, together with inverse Magnus force, plays an important role in the formation of the secondary circle. In addition, the cyclotron radius is seen to change periodically during the cycloid motion. Force analysis and comparison experiments have shown that the cycloid motions are distinctive features of an irregular grain immersed in a plasma. Project supported by the National Natural Science Foundation of China (Grant Nos. 11205044 and 11405042), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2011201006 and A2012201015), the Research Foundation of Education Bureau of Hebei Province, China (Grant No. Y2012009), the Program for Young Principal Investigators of Hebei Province, and the Midwest Universities Comprehensive Strength Promotion Project.

  5. Topological dynamics and current-induced motion in a skyrmion lattice

    NASA Astrophysics Data System (ADS)

    Martinez, J. C.; Jalil, M. B. A.

    2016-03-01

    We study the Thiele equation for current-induced motion in a skyrmion lattice through two soluble models of the pinning potential. Comprised by a Magnus term, a dissipative term and a pinning force, Thiele’s equation resembles Newton’s law but in virtue of the topological character to the first, it differs significantly from Newtonian mechanics and because the Magnus force is dominant, unlike its mechanical counterpart—the Coriolis force—skyrmion trajectories do not necessarily have mechanical counterparts. This is important if we are to understand skyrmion dynamics and tap into its potential for data-storage technology. We identify a pinning threshold velocity for the one-dimensional pinning potential and for a two-dimensional attractive potential we find a pinning point and the skyrmion trajectories toward that point are spirals whose frequency (compare Kepler’s second law) and amplitude-decay depend only on the Gilbert constant and potential at the pinning point. Other scenarios, e.g. other choices of initial spin velocity, a repulsive potential, etc are also investigated.

  6. Aerodynamics in the classroom and at the ball park

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2012-04-01

    Experiments suitable for classroom projects or demonstrations are described concerning the aerodynamics of polystyrene balls. A light ball with sufficient backspin can curve vertically upward through the air, defying gravity and providing a dramatic visual demonstration of the Magnus effect. A ball projected with backspin can also curve downward with a vertical acceleration greater than that due to gravity if the Magnus force is negative. These effects were investigated by filming the flight of balls projected in an approximately horizontal direction so that the lift and drag forces could be easily measured. The balls were also fitted with artificial raised seams and projected with backspin toward a vertical target in order to measure the sideways deflection over a known horizontal distance. It was found that (a) a ball with a seam on one side can deflect either left or right depending on its launch speed and (b) a ball with a baseball seam can also deflect sideways even when there is no sideways component of the drag or lift forces acting on the ball. Depending on the orientations of the seam and the spin axis, a sideways force on a baseball can arise either if there is rough patch on one side of the ball or if there is a smooth patch. A scuff ball with a rough patch on one side is illegal in baseball. The effect of a smooth patch is a surprising new observation.

  7. STS-112 crew walks out of O&C building before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew wave to spectators as they exit the Operations and Checkout Building for their ride to Launch Pad 39B and the launch scheduled 3:46 p.m. EDT. Leading the way are Pilot Pamela Melroy and Commander Jeffrey Ashby. In the second row are Mission Specialists David Wolf (left) and Sandra Magnus. Behind them are Mission Specialists Fyodor Yurchikhin and Piers Sellers. Sellers, Magnus and Yurchikhin are making their first Shuttle flights. STS-112 is the 15th assembly flight to the International Space Station, carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss to the Station.

  8. Interaction of vortices with ultrasound and the acoustic Faraday effect in type-II superconductors

    SciTech Connect

    Dominguez, D.; Bulaevskii, L.; Ivlev, B. |; Maley, M.; Bishop, A.R.

    1996-03-01

    We study the interaction of sound waves with vortices in type-II superconductors, taking into account pinning and electrodynamic forces between vortices and crystal displacements. We propose ultrasound techniques as a method for obtaining information about vortex dynamics. This is particularly appropiate at low temperatures where transport measurements are ineffective. The changes in sound velocity and attenuation due to vortices, can provide information on the elastic constants of the vortex system and on vortex dissipation, respectively. At low temperatures the Magnus force acting on vortices leads to the {ital acoustic} {ital Faraday} {ital effect}: there is a rotation of the polarization plane of tranverse sound waves propagating along the magnetic field. This effect is linear in the Magnus force and magnetic field in crystals with equivalent {ital a} and {ital b} axes for a field parallel to the {ital c} axis. We discuss how this effect can be measured by means of either pulse-echo techniques or standing sound waves. Also, we show that an ac electromagnetic field acting on the vortex system can generate ultrasound. We calculate the amplitude of the generated sound waves in the linear regime and compare with recent experiments. {copyright} {ital 1996 The American Physical Society.}

  9. Spin-orbit torques and anisotropic magnetization damping in skyrmion crystals

    NASA Astrophysics Data System (ADS)

    Hals, Kjetil M. D.; Brataas, Arne

    2014-02-01

    The length scale of the magnetization gradients in chiral magnets is determined by the relativistic Dzyaloshinskii-Moriya interaction. Thus, even conventional spin-transfer torques are controlled by the relativistic spin-orbit coupling in these systems, and additional relativistic corrections to the current-induced torques and magnetization damping become important for a complete understanding of the current-driven magnetization dynamics. We theoretically study the effects of reactive and dissipative homogeneous spin-orbit torques and anisotropic damping on the current-driven skyrmion dynamics in cubic chiral magnets. Our results demonstrate that spin-orbit torques play a significant role in the current-induced skyrmion velocity. The dissipative spin-orbit torque generates a relativistic Magnus force on the skyrmions, whereas the reactive spin-orbit torque yields a correction to both the drift velocity along the current direction and the transverse velocity associated with the Magnus force. The spin-orbit torque corrections to the velocity scale linearly with the skyrmion size, which is inversely proportional to the spin-orbit coupling. Consequently, the reactive spin-orbit torque correction can be the same order of magnitude as the nonrelativistic contribution. More importantly, the dissipative spin-orbit torque can be the dominant force that causes a deflected motion of the skyrmions if the torque exhibits a linear or quadratic relationship with the spin-orbit coupling. In addition, we demonstrate that the skyrmion velocity is determined by anisotropic magnetization damping parameters governed by the skyrmion size.

  10. Spin-Orbit Torques and Anisotropic Magnetization Damping in Skyrmion Crystals

    NASA Astrophysics Data System (ADS)

    Hals, Kjetil; Brataas, Arne

    2014-03-01

    We theoretically study the effects of reactive and dissipative homogeneous spin-orbit torques and anisotropic damping on the current-driven skyrmion dynamics in cubic chiral magnets. Our results demonstrate that spin-orbit torques play a significant role in the current-induced skyrmion velocity. The dissipative spin-orbit torque generates a relativistic Magnus force on the skyrmions, whereas the reactive spin-orbit torque yields a correction to both the drift velocity along the current direction and the transverse velocity associated with the Magnus force. The spin-orbit torque corrections to the velocity scale linearly with the skyrmion size, which is inversely proportional to the spin-orbit coupling. Consequently, the reactive spin-orbit torque correction can be the same order of magnitude as the non-relativistic contribution. More importantly, the dissipative spin-orbit torque can be the dominant force that causes a deflected motion of the skyrmions if the torque exhibits a linear or quadratic relationship with the spin-orbit coupling. In addition, we demonstrate that the skyrmion velocity is determined by anisotropic magnetization damping parameters governed by the skyrmion size.

  11. STS-112 Flight Day 1 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On the first day of STS-112 the crew (Commander Jeff Ashby, Pilot Pam Melroy and Mission Specialists Sandy Magnus, Piers Sellers, David Wolf and Fyodor Yurchikhin) are shown preparing for launch at Kennedy Space Center, being transported to the Space Shuttle Atlantis at its launch pad, and being seated in the Orbiter. During the launch, the External Tank (ET) camera, mounted to the top of Atlantis's ET and aimed downward) will provide never before seen footage of the shuttle during lift-off. Following the final countdown and liftoff, the ET camera provides footage as Atlantis quickly leaves the Earth behind, at speeds over 2,800 miles per hour. Following orbital insertion, the shuttle's payload bay doors are shown opening in footage provided by a payload bay camera. Sellers and Magnus narrate their thoughts during a replay of the initial launch sequence, shortly after entering orbit. Following the tape, they are shown in the crewcabin with the rest of the crew, and they each share brief thoughts.

  12. STS-112 Flight Day 1 Highlights

    NASA Astrophysics Data System (ADS)

    2002-10-01

    On the first day of STS-112 the crew (Commander Jeff Ashby, Pilot Pam Melroy and Mission Specialists Sandy Magnus, Piers Sellers, David Wolf and Fyodor Yurchikhin) are shown preparing for launch at Kennedy Space Center, being transported to the Space Shuttle Atlantis at its launch pad, and being seated in the Orbiter. During the launch, the External Tank (ET) camera, mounted to the top of Atlantis's ET and aimed downward) will provide never before seen footage of the shuttle during lift-off. Following the final countdown and liftoff, the ET camera provides footage as Atlantis quickly leaves the Earth behind, at speeds over 2,800 miles per hour. Following orbital insertion, the shuttle's payload bay doors are shown opening in footage provided by a payload bay camera. Sellers and Magnus narrate their thoughts during a replay of the initial launch sequence, shortly after entering orbit. Following the tape, they are shown in the crewcabin with the rest of the crew, and they each share brief thoughts.

  13. ConnesFusionTensorProduct/Photon GluonFusion in Mitochondria

    NASA Astrophysics Data System (ADS)

    Wh-Maksoed, Prodi Of Physics Ui, Depok 16415-Indonesia; Ssi, Wh-Maksoed

    2016-05-01

    As in AJ Wassermann distinguished of classical invariant theory & quantum invariant theory subfactor, in S. Palcoux:``From Neveu-Schwarz Subfactors & Connes Fusion'' described the subfactor theory & Witt-algebra whereas Andreas Thom's explanation about ConnesFusionTensorProduct/CFTP related Connes fusion to composition of homomorphism (i). classical tensor product O-X adds the changes,(ii). Relative tensor product H-X preserve the changes. For photonGluonFusion/PGF defined:''photon is the gauge boson of QED, the simplest of all boson'' devotes to CFT as ``quantum field theory which are invariant under conformal transformation & in 2D there are infinite dimensional algebra. Alain Connes states theirselves Connes fusion as ``associative tensor operation'' to be in coincidences with ``their dynamic behavior driven by the balance in mitochondrial fusion & fission (Carveney, 2007) from Peter Alexander Williams: ``Retinal neuronal remodeling in a model of Optic Atrophy'', Dec, 2011. Great acknowledged to the VicePresident of the R.I, HE.Mr. Drs. M. JUSUF KALLA.

  14. Kinetics of gas phase oxygen control system (OCS) for stagnant and flowing Pb-Bi Systems

    NASA Astrophysics Data System (ADS)

    Lefhalm, C. H.; Knebel, J. U.; Mack, K. J.

    2001-07-01

    Pb and Pb-Bi are known to be very corrosive to structural materials at elevated temperatures. In recent studies, the necessity of measurement and control of the oxygen concentration in the liquid metal in order to safely operate a liquid Pb or Pb-Bi loop has been shown. The dynamic behaviour of the gas phase oxygen control system (OCS), which was developed at Forschungszentrum Karlsruhe (FZK), is investigated with respect to diffusion as the limiting process of oxygen exchange between the gas phase and the liquid metal. In this paper the development of a physical model for this diffusion process is described and compared to experimental results of a stagnant liquid Pb-Bi system. The experimental findings are in very good agreement with the theoretical equations describing the thermodynamic and kinetic behaviour of such a system. Recent investigations in a Pb-Bi loop at the Karlsruhe Lead Laboratory (KALLA) indicate that this gas phase OCS is a promising candidate system for an accelerator-driven subcritical system (ADS).

  15. Deep pockets for deep seas

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Peter Auster, a fisheries ecologist with the National Undersea Research Center in Connecticut, plans to assess degradation of the deep-shelf seafloor from bottom trawling. Magnus Ngoile, an official with Tanzania's National Environmental Management Council, will work on building capacity of poor villagers to protect their coastline. And Alison Rieser, a lawyer with the University of Maine School of Law, will produce a textbook to educate scientists on how to apply the law for marine conservation.These individuals are among 11 recipients of the Pew Charitable Trust's 10th annual marine conservation fellowships, announced on July 12. With each recipient receiving an award of $150,000, the program is the world's largest award for marine conservationists. Other 1999 recipients will be involved with areas including investigating marine pollution in the Arctic region, examining economic incentives for conservation in Baja, Mexico, and establishing a marine conservation biology training program for minority students.

  16. A Common Miscitation of William Gilbert

    NASA Astrophysics Data System (ADS)

    Sluijs, Marinus Anthony

    2014-04-01

    Dozens of scientific textbooks [e.g., Spaldin, 2011, p. v; Krijgsman and Langereis, 2009, p. 252; Prölls, 2004, p. 211; Merrill et al., 1996, p. 7; Livingston, 1996, p. 27; Blakely, 1996, pp. xiv, 154; Gillmor, 1990, p. 9] attribute the famous dictum magnus magnes ipse est globus terrestris ("the terrestrial globe is itself a big magnet") to the English physician and scientist William Gilbert (1544-1603). It is repeatedly claimed that these words were contained in the title of Gilbert's book or one of his chapters [e.g., Carlowicz and Lopez, 2002, n.p.; Courtillot, 2002, pp. 26, 49; Lang and Whitney, 1991, p. 120]. Certainly, they convey the thrust of Gilbert's De Magnete, in which it was argued for the first time that the Earth sustains its own magnetic dipole field, on the basis of experimentation on magnets.

  17. Augmentation of transfers for a quadriplegic patient using an implanted FNS system. Case report.

    PubMed

    Marsolais, E B; Scheiner, A; Miller, P C; Kobetic, R; Daly, J J

    1994-08-01

    A 22 year old man with incomplete quadriplegia (C6-7) was unable to perform either a sliding or a pivot transfer. He was instrumented with an implanted functional neuromuscular stimulation (FNS) system, radio frequency-linked to a belt-worn controller. The system activated eight muscles selected from among quadriceps, hamstrings, posterior portion of the adductor magnus, gluteus maximus, and erector spinae, bilaterally. The two-stage implantation procedure included electrode implantation with percutaneous leads followed by stimulator implantation and removal of the percutaneous leads. All implants were well tolerated with no adverse effects. The subject was able independently to put on the external controller portion of the system and to perform a standing pivot transfer with only standby assistance. An unexpected outcome of the FNS system use was increased voluntary upper body strength that resulted in improvement of the sliding transfer from 'inability' to 'independent'. PMID:7970864

  18. STS-112 crew practices emergency egress training during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - STS-112 Mission Specialist Sandra Magnus (left) sits in the slidewire basket basket on the 195-foot level of the Fixed Service Structure, Launch Pad 39B, while Mission Specialist Piers Sellers (right) reaches for the release lever. They and the rest of the crew are practicing emergency egress from the pad during Terminal Countdown Demonstration Test activities. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  19. Comparison of four commercial brucella agar media for growth of anaerobic organisms.

    PubMed Central

    Mangels, J I; Douglas, B P

    1989-01-01

    Four different commercial brucella blood agar plating media (Anaerobe Systems, BBL Microbiology Systems, Remel, and Scott Laboratories) were compared for the abilities to recover anaerobic organisms from clinical specimens and to support the growth of American Type Culture Collection anaerobic stock cultures. Following 24 h of incubation in an anaerobe chamber, Anaerobe Systems prereduced, anaerobically sterilized brucella plates yielded 63% of the total clinical anaerobe isolates, the Scott medium yielded 51%, the Remel medium yielded 42%, and the BBL medium yielded 37%. Poor growth of Peptostreptococcus magnus, P. anaerobius, Fusobacterium necrophorum, F. nucleatum, and pigmented Bacteroides spp. was observed on brucella media obtained from BBL, Remel, and Scott. Data obtained with stock anaerobic cultures showed that Anaerobe Systems plates yielded good growth and produced a larger colony size with all of the strains tested in 1 day, whereas poor growth of Peptostreptococcus spp., B. melaninogenicus, and Fusobacterium spp. was noted on brucella media from BBL, Remel, and Scott. PMID:2584378

  20. A numerical study of the motion of a neutrally buoyant cylinder in two dimensional shear flow

    NASA Astrophysics Data System (ADS)

    Pan, Tsorng-Whay; Huang, Shih-Lin; Chen, Shih-Di; Chu, Chin-Chou; Chang, Chien-Cheng

    2012-11-01

    We have investigated the motion of a neutrally buoyant cylinder of circular or elliptic shape in two dimensional shear flow of a Newtonian fluid by direct numerical simulation. The numerical results are validated by comparisons with existing theoretical, experimental and numerical results, including a power law of the normalized angular speed versus the particle Reynolds number. The centerline between two walls is an expected equilibrium position of the cylinder mass center in shear flow. When placing the particle away from the centerline initially, it migrates toward another equilibrium position for higher Reynolds numbers due to the interplay between the slip velocity, the Magnus force, and the wall repulsion force. T-W Pan acknowledges the support by the US NSF and S-L Huang, S-D Chen, C-C Chu, C-C Chang acknowledge the support by the National Science Council of Taiwan, ROC.

  1. Non-Abelian evolution of electromagnetic waves in a weakly anisotropic inhomogeneous medium

    SciTech Connect

    Bliokh, K. Yu.; Frolov, D. Yu.; Kravtsov, Yu. A.

    2007-05-15

    A theory of electromagnetic wave propagation in a weakly anisotropic smoothly inhomogeneous medium is developed, based on the quantum-mechanical diagonalization procedure applied to Maxwell equations. The equations of motion for the translational (ray) and intrinsic (polarization) degrees of freedom are derived ab initio. The ray equations take into account the optical Magnus effect (spin Hall effect of photons) as well as trajectory variations owing to the medium anisotropy. Polarization evolution is described by the precession equation for the Stokes vector. In the generic case, the evolution of wave turns out to be non-Abelian: it is accompanied by mutual conversion of the normal modes and periodic oscillations of the ray trajectories analogous to electron zitterbewegung. The general theory is applied to examples of wave evolution in media with circular and linear birefringence.

  2. The Versatile Elastohydrodynamics of a Free Particle near a Thin Soft Wall

    NASA Astrophysics Data System (ADS)

    Salez, Thomas; Saintyves, Baudouin; Mahadevan, L.

    2015-03-01

    We address the free motion of a buoyant particle inside a viscous fluid, in the vicinity of a thin compressible elastic wall. After discussing the main scalings, we obtain analytically the dominant drag forces within the soft lubrication approximation. By including those into the equations of motion of the particle, we establish a general governing system of three coupled nonlinear and singular differential equations, that describe the three essential motions: sedimentation, hydroplaning, and hydrospinning, through four dimensionless control parameters. Numerical integration allows us to predict a wide zoology of exotic solutions - despite the low-Reynolds feature of the flow - including: spontaneous oscillation, Magnus-like effect, enhanced sedimentation, and boomerang-like effect. We compare these predictions to experiments. The presented elementary approach could be of interest in the description of a broad variety of elastohydrodynamical phenomena, including: landslides, ageing of cartilaginous joints, and motion of a cell in a microfluidic channel or in a blood vessel.

  3. Analysis of the performance of a phase alternated multiple pulse sequence in spin I = 7/2 zero-field NQR spectroscopy

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, A.

    Zero-field nuclear magnetic resonance spectroscopy of solids containing quadrupole nuclei usually results in broad spectral lines. This line-broadening is due mainly to the inhomogeneity of the electric field gradient (EFG) at the quadrupolar nuclear site. High resolution spectra of such solids can be obtained with the application of suitably designed multiple radiofrequency (RF) pulse sequences. The performance is reported for a periodic and cyclic phase alternated multiple RF pulse sequence (PAPS) in a spin I = 7/2 system in zero external magnetic field. Average Hamiltonian theory based on the Magnus expansion is used to solve the time-dependent Liouville-von Neumann equation of motion of the spin system under the effect of the PAPS sequence. Single transition operators are employed in the spin dynamics calculations. It is shown that the multiple pulse seqeuncearation pulse, suppresses the EFG inhomogeneity to a maximum extent when = 2 . [-- ] 2 , where is the prep1 2 2 N 1 2 1

  4. STS-112 Crew walkout of O&C building for TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew heads for the Astrovan and a ride to the launch pad for a simulated countdown. From left are Mission Specialists Fyodor Yurchikhin (RSA), David Wolf and Piers Sellers; Pilot Pamela Melroy; Mission Specialist Sandra Magnus; and Commander Jeffrey Ashby. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  5. STS-112 Crew walkout of O&C building for TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew strides out of the Checkout and Operations Building on their way to the launch pad and a simulated countdown. On the left, front to back, are Pilot Pamela Melroy and Mission Specialists David Wolf and Fyodor Yurchikhin (RSA). On the right, front to back, are Commander Jeffrey Ashby and Mission Specialists Sandra Magnus and Piers Sellers. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  6. STS-112 crew arrives at KSC's SLF for launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- After their arrival at the KSC Shuttle Landing Facility, the STS-112 crew members stride happily to the side of the parking apron and a photo opportunity. From left are Commander Jeffrey Ashby, Mission Specialist Piers Sellers, Pilot Pamela Melroy and Mission Specialists David Wolf, Sandra Magnus and Fyodor Yurchikhin, who is with the Russian Space Agency. Launch is scheduled for Oct. 2 between 2 and 6 p.m. STS-112, aboard Space Shuttle Atlantis, is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. The 11-day mission includes three spacewalks.

  7. STS-112 crew arrives at KSC's SLF for launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 Mission Specialist Sandra Magnus is happy to return to KSC to prepare for launch. She will be making her first Shuttle flight. STS-112, aboard Space Shuttle Atlantis, is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. The 11-day mission includes three spacewalks. Launch is scheduled for Oct. 2 between 2 and 6 p.m.

  8. STS-112 crew take break during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 Commander Jeffrey Ashby, Mission Specialist Sandra Magnus, and Pilot Pamela Melroy take a momentary break from training at Pad 39B during Terminal Countdown Demonstration Test activities, which include a simulated launch countdown. Launch of STS-112 aboard Space Shuttle Atlantis is scheduled for Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  9. STS-112 crew practices emergency egress training during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 Mission Specialist Sandra Magnus takes a break during emergency egress practice on the 195-foot level of the Fixed Service Structure, Launch Pad 39B. She and the rest of the crew are taking part in Terminal Countdown Demonstration Test activities, which include a simulated launch countdown. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  10. STS-112 crew boarding Atlantis for TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- In the White Room at Launch Pad 39B, STS-112 Mission Specialist Sandra Magnus, Ph.D., receives assistance with her spacesuit during a simulated launch countdown, part of Terminal Countdown Demonstration Test activities, a dress rehearsal for launch. Launch of STS-112 aboard Space Shuttle Atlantis is scheduled for Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, which will be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  11. STS-112 crew practices emergency egress training during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - During emergency egress practice on the 195-foot level of the Fixed Service Structure, Launch Pad 39B, STS-112 Mission Specialist Sandra Magnus opens her helmet visor. She and the rest of the crew are taking part in Terminal Countdown Demonstration Test activities, which include a simulated launch countdown. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  12. STS-112 Atlantis landing at KSC's shuttle landing facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis approaches the runway at the Shuttle Landing Facility, completing the 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment. The returning crew of Atlantis are Commander Jeffrey Ashby, Pilot Pamela Melroy, and Mission Specialists David Wolf, Piers Sellers, Sandra Magnus and Fyodor Yurchikhin. This landing is the 60th at KSC in the history of the Shuttle program.

  13. [Topography and cytoarchitecture of the raphe nuclei in the rat].

    PubMed

    Hölzel, B; Pfister, C

    1981-01-01

    Within the raphe complex of adult rat, ribonucleoproteids have been demonstrated by means of the Gallocyanin-Chromalaun-reaction according to EINARSON. The following subnuclei were characterized in a topographical and cytological view: nucleus raphe dorsalis, nucleus centralis superior, nucleus raphe pontis, nucleus raphe magnus, nucleus raphe obscurus, nucleus raphe pallidus. In all raphe nuclei 3 neuron types could be differentiated which differ both with respect to size and shape of their soma and nuclear morphology and intensity and distribution of the cellular ribonucleoproteids: 1. Large polygonal neurons, 2. medium-sized fusiform neurons, 3. small pyriform neurons. The results may serve as a basis for performing further investigations of these brain regions, employing morphological and pharmacological methods. PMID:7338625

  14. Ethanol and oxidative stress.

    PubMed

    Sun, A Y; Ingelman-Sundberg, M; Neve, E; Matsumoto, H; Nishitani, Y; Minowa, Y; Fukui, Y; Bailey, S M; Patel, V B; Cunningham, C C; Zima, T; Fialova, L; Mikulikova, L; Popov, P; Malbohan, I; Janebova, M; Nespor, K; Sun, G Y

    2001-05-01

    This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Albert Y. Sun. The presentations were (1) Ethanol-inducible cytochrome P-4502E1 in alcoholic liver disease, by Magnus Ingelman-Sundberg and Etienne Neve; (2) Regulation of NF-kappaB by ethanol, by H. Matsumoto, Y. Nishitani, Y. Minowa, and Y. Fukui; (3) Chronic ethanol consumption increases concentration of oxidized proteins in rat liver, by Shannon M. Bailey, Vinood B. Patel, and Carol C. Cunningham; (4) Antiphospholipids antibodies and oxidized modified low-density lipoprotein in chronic alcoholic patients, by Tomas Zima, Lenka Fialova, Ludmila Mikulikova, Ptr Popov, Ivan Malbohan, Marta Janebova, and Karel Nespor; and (5) Amelioration of ethanol-induced damage by polyphenols, by Albert Y. Sun and Grace Y. Sun. PMID:11391077

  15. [Histotopographic and morphometric studies of the intramural coronary arteries in the trabecula septomarginalis of swine and pigmy goats].

    PubMed

    Lorenz, G; Guski, H

    1990-01-01

    Up to six arteries traverse from the interventricular septum to the M. papillaris magnus in the trabecula septomarginalis (moderator band) of swine and pygmy goat. Musculo-elastic intimal thickenings, many of them quite extensive, are recordable from along the entire length of all these intramural coronary arteries which are between 50 microns and 300 microns in diameter. The conclusion may be drawn from the results of morphometric analysis that coronary arteries undergo enlargement in response to increased intimal thickening and that such enlargement does not lead to narrowing of the lumen. Peculiarities in wall structure of the arteries in the trabecula septomarginalis are interpreted as adaptive processes of the vascular wall to the extraordinary stress on those vessels. PMID:2327188

  16. High-frequency approximation for periodically driven quantum systems from a Floquet-space perspective

    NASA Astrophysics Data System (ADS)

    Eckardt, André; Anisimovas, Egidijus

    2015-09-01

    We derive a systematic high-frequency expansion for the effective Hamiltonian and the micromotion operator of periodically driven quantum systems. Our approach is based on the block diagonalization of the quasienergy operator in the extended Floquet Hilbert space by means of degenerate perturbation theory. The final results are equivalent to those obtained within a different approach (Rahav et al 2003 Phys. Rev. A 68 013820), (Goldman and Dalibard 2014 Phys. Rev. X 4 031027) and can also be related to the Floquet-Magnus expansion (Casas et al 2001 J. Phys. A 34 3379). We discuss that the dependence on the driving phase, which plagues the latter, can lead to artifactual symmetry breaking. The high-frequency approach is illustrated using the example of a periodically driven Hubbard model. Moreover, we discuss the nature of the approximation and its limitations for systems of many interacting particles.

  17. STS-112 crew talks to media after landing

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - The STS-112 crew pauses at the microphone in front of Atlantis after exiting the crew transport vehicle. From left are Mission Specialist Sandra Magnus, Pilot Pamela Melroy, Commander Jeffrey Ashby, and Mission Specialists David Wolf, Fyodor Yurchikhin and Piers Sellers. The flawless landing of Space Shuttle Atlantis on Runway 33 at KSC completed a 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment.

  18. [SCIENCE AND DREAMS IN THE MIDDLE AGES: IL "DE SOMNIIS" DI BOEZIO DI DACIA].

    PubMed

    Feti, Viola

    2015-01-01

    Boethius of Dacia's opera "De somnis" can be defined as a brief treaty that partially follows the traditional quaestio scheme. It includes a passage that seems to copy Etienne Tempier's proposition number sixty-five, which condemns the importance attributed to astrology by many medieval authors. Boethius moves off Aristotle's "De somno et vigilia" idea of physiological dreams to assert a new kind of oneiric phenomena linked to constellations, that, according to the author, aren't divinely inspired, whereas they are to be considered as natural events. Boethius isn't the only philosopher who writes about this particular type of dream as another medieval author, Albertus Magnus, in his "Speculum Astronomiae", describes astrology and its relationship to medicine. PMID:26946816

  19. Spinal and locus coeruleus noradrenergic lesions abolish the analgesic effects of 5-methoxy-N,N-dimethyltryptamine.

    PubMed

    Danysz, W; Jonsson, G; Minor, B G; Post, C; Archer, T

    1986-07-01

    Two experiments were performed on Sprague-Dawley rats to study the effects of noradrenaline and 5-hydroxytryptamine depletion upon the antinociceptive effects of acute 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) administration. 6-Hydroxydopamine-induced lesions following microinjections to either the locus coeruleus or the spinal cord (lumbar) abolished completely 5-MeODMT-induced analgesia in the tail-flick, hot-plate, and shock titration tests whereas 5,7-dihydroxytryptamine-induced lesions of the nucleus raphe magnus and the lumbar spinal cord attenuated 5-MeODMT analgesia in the tail-flick and shock titration tests. Thus, the experiments serve to demonstrate an important interaction between descending noradrenergic and serotonergic pathways, possibly at a spinal locus. PMID:3015120

  20. What Is the Best Launch Angle To Hit a Home Run?

    NASA Astrophysics Data System (ADS)

    Kagan, David

    2010-04-01

    Your students will proudly raise their hands and answer, "45 degrees!" They are, however, answering a different question. It is true that in the absence of air resistance, for a given initial speed, the launch angle that maximizes the range is 45°. For a real homer, there are many complicating factors that make the question far more challenging to answer. Here is a partial list: 1. The initial speed off the bat is not fixed. Garvey's law, "The harder you hit it, the further it goes" is definitely at play; 2. Air resistance is a substantial influence on the flight of the ball. ; 3. The backspin on a well-hit ball creates lift due to the Magnus effect.2; 4. Atmospheric conditions such as humidity, temperature, air density, and the wind affect the motion as well.3; 5. Baseball parks are unique in size and shape. So, a home run in one park may not be a home run in another.

  1. How Far Would a Home Run Really Have Gone?

    NASA Astrophysics Data System (ADS)

    Sherwin, W. G.; Cheng, Y. C.; Chunko, J. D.; Eagan, T. P.; Brown, R. W.

    2002-04-01

    A controversial issue in professional baseball arises from attempts to estimate how far home run balls would have traveled if they had not hit some obstruction, such as a scoreboard or bleacher seating. A Runge-Kutta numerical simulation model is developed for baseball trajectories including the effects of velocity-dependent drag forces, velocity-dependent Magnus spin forces (including a model for the decrease of the spin rate over the trajectory), and the wind. The computational model is used to build a numerical catalog for the combination of initial ball speeds and angles that give rise to a set of trajectories that have the same final impact point (e.g., on the scoreboard). The data required by an observer to estimate the actual home run range are discussed. A homerun hit by Mark McGwire against the Cleveland Indians on 30 April 1997 that dented the Jacobs Field scoreboard is analyzed.

  2. STS-112 Flight Day 2 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On the second flight day of STS-112 (Commander Jeff Ashby, Pilot Pam Melroy and Mission Specialists Sandy Magnus, Piers Sellers, David Wolf and Fyodor Yurchikhin), video footage is shown of the Space Shuttle Atlantis's payload bay, which contains the International Space Station's (ISS) S1 (S-One) truss section, which will be installed on the ISS by Sellers and Wolf during EVAs (extravehicular activities) following Atlantis's docking with the station. Also shown, via a camera on the shuttle's robotic arm, are the three radiators that reside on the truss structure and will provide cooling capability for the entire station. During this flight day, Atlantis passes over Southern California, Nevada, Wyoming, South Dakota, and Minnesota in a track that will eventually bring it over Newfoundland and Labrador.

  3. STS-112 crew during meal before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew relaxes at the traditional crew meal before getting ready for launch later in the day. Seated, from left, are Mission Specialist Piers Sellers and Fyodor Yurchikhin, Pilot Pamela Melroy, Commander Jeffrey Ashby, and Mission Specialists Sandra Magnus and David Wolf. STS-112 is the 15th assembly flight to the International Space Station, carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. On the 11-day mission, three spacewalks are planned to attach the S1 truss to the Station. Launch is scheduled for 3:46 p.m. EDT from Launch Pad 39B.

  4. An Unusual Course and Termination of Small Saphenous Vein: A Case Report.

    PubMed

    Shetty, Prakashchandra; D'Souza, Melanie Rose; Nayak, Satheesha B

    2016-03-01

    The superficial veins of the lower limb can vary in their course and termination. We report a relatively rare type of variation in the course and termination of small saphenous vein. The small saphenous vein had normal origin and course in the leg. However, instead of terminating into the popliteal vein, it continued up in the posterior compartment of the thigh and terminated into the femoral vein after piercing the fleshy part of the adductor magnus muscle. This course might lead to varicosity of the small saphenous vein due to the compression by the fleshy fibres of adductor magus near its termination. The case may be of interest to general and plastic surgeons and even cardiothoracic surgeons. PMID:27134850

  5. An Unusual Course and Termination of Small Saphenous Vein: A Case Report

    PubMed Central

    Shetty, Prakashchandra; D’Souza, Melanie Rose

    2016-01-01

    The superficial veins of the lower limb can vary in their course and termination. We report a relatively rare type of variation in the course and termination of small saphenous vein. The small saphenous vein had normal origin and course in the leg. However, instead of terminating into the popliteal vein, it continued up in the posterior compartment of the thigh and terminated into the femoral vein after piercing the fleshy part of the adductor magnus muscle. This course might lead to varicosity of the small saphenous vein due to the compression by the fleshy fibres of adductor magus near its termination. The case may be of interest to general and plastic surgeons and even cardiothoracic surgeons. PMID:27134850

  6. International Program and Local Organizing Committees

    NASA Astrophysics Data System (ADS)

    2012-12-01

    International Program Committee Dionisio Bermejo (Spain) Roman Ciurylo (Poland) Elisabeth Dalimier (France) Alexander Devdariani (Russia) Milan S Dimitrijevic (Serbia) Robert Gamache (USA) Marco A Gigosos (Spain) Motoshi Goto (Japan) Magnus Gustafsson (Sweden) Jean-Michel Hartmann (France) Carlos Iglesias (USA) John Kielkopf (USA) John C Lewis (Canada) Valery Lisitsa (Russia) Eugene Oks (USA) Christian G Parigger (USA) Gillian Peach (UK) Adriana Predoi-Cross (Canada) Roland Stamm (Germany) Local Organizing Committee Nikolay G Skvortsov (Chair, St Petersburg State University) Evgenii B Aleksandrov (Ioffe Physico-Technical Institute, St Petersburg) Vadim A Alekseev (Scientific Secretary, St Petersburg State University) Sergey F Boureiko (St.Petersburg State University) Yury N Gnedin (Pulkovo Observatory, St Petersburg) Alexander Z Devdariani (Deputy Chair, St Petersburg State University) Alexander P Kouzov (Deputy Chair, St Petersburg State University) Nikolay A Timofeev (St Petersburg State University)

  7. Many-body energy localization transition in periodically driven system

    NASA Astrophysics Data System (ADS)

    D'Alessio, Luca; Polkovnikov, Anatoli

    2013-03-01

    According to the second law of thermodynamics the total entropy and energy of a system is increased during almost any dynamical process. Notable exceptions are known in noninteracting systems of particles moving in periodic potentials. Here the phenomenon of dynamical localization can prevent heating beyond certain threshold. However, it was believed that driven ergodic systems will always heat without bound. Here, on the contrary, we report strong evidence of dynamical localization transition in periodically driven ergodic systems in the thermodynamic limit. This phenomenon is reminiscent of many-body localization in energy space. We report numerical evidence based on exact diagonalization of small spin chains and theoretical arguments based on the Magnus expansion. Our findings are valid for both classical and quantum systems.

  8. On the transgressiveness of ambiguity: Richard Bruce Nugent and the flow of sexuality and race.

    PubMed

    Bauer, J Edgar

    2015-01-01

    The study focuses on the slender corpus of literary work by Harlem Renaissance poet, author and visual artist Richard Bruce Nugent (1906-1987), arguably America's foremost Black aesthete. As an individualist in the footsteps of post-Hegelian and pre-Nietzschean philosopher Max Stirner (1806-1856), Nugent sought to re-think sexuality and race beyond fixed schemes of categorial distribution. To this end, Nugent deployed a strategy of sexual and racial ambiguity that aimed at situating the uniquely sexed and raced individual within the continuities of ever-diversifying Nature. Nugent's deconstructive approach of sexuality and race proves to be convergent with (but not genealogically dependent on) the universalization of sexual intermediariness and racial miscegenation postulated by German-Jewish sexologist Magnus Hirschfeld during the first third of the twentieth century. Nugent's non-identitarian conception of sex acts anticipated by more than a decade comparable insights propounded by Alfred Kinsey. PMID:25710478

  9. [CCA of water beetles' distribution and environmental factors in lentic samples of north Changbai Mountain].

    PubMed

    We, Yulian; Ji, Lanzhu; Wang, Miao; Zhao, Min

    2002-01-01

    The relationship between 28 species water beetles in 12 lentic samples and environmental factors of North Chang-bai Mountain was studied by Cononical Correspondence Analysis (CCA). The results showed that degree of underwater humus and altitude are the major factors correlated with beetles distribution, and the correlation coefficients of environmental factors and axes of CCA were 0.8371 and 0.7206 respectively, while water temperature and plant density also had certain effects. Under the influence of environmental factors, the water beetles' populations were different in different habitat. Coelambus impressopunctatus, Colymbetes magnus, Helophorus browni, Haliplus spp. distributed in deep water pool. Water temperature was not important for those beetles. Ilybius sp. and Limnebius glabriventris correlated with altitude and humus. PMID:11962329

  10. Comparative Susceptibility of Anaerobic Bacteria to Minocycline, Doxycycline, and Tetracycline

    PubMed Central

    Chow, Anthony W.; Patten, Valerie; Guze, Lucien B.

    1975-01-01

    The comparative susceptibility of 622 recent clinical isolates of anaerobic bacteria to minocycline, doxycycline, and tetracycline was determined by an agar-dilution technique. In addition to Bacteroides fragilis, a variety of other anaerobic bacteria was resistant to achievable blood concentrations of tetracycline (55% inhibited by 6.25 μg/ml) and doxycycline (58% inhibited by 2.5 μg/ml). In contrast, minocycline was significantly more active (P < 0.05) than both doxycycline and tetracycline, and 70% of strains were inhibited by achievable blood concentrations of this antibiotic (2.5 μg/ml). The enhanced activity of minocycline was particularly striking for Peptococcus asaccharolyticus, P. magnus, P. prevotii, Peptostreptococcus anaerobius, and Bacteroides melaninogenicus. Further evaluation of the clinical efficacy of minocycline against anaerobic infections is indicated. PMID:1137358

  11. STS-112 Atlantis landing at KSC's shuttle landing facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - Space Shuttle Atlantis drops to the runway at the Shuttle Landing Facility, completing the 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment. The returning crew of Atlantis are Commander Jeffrey Ashby, Pilot Pamela Melroy, and Mission Specialists David Wolf, Piers Sellers, Sandra Magnus and Fyodor Yurchikhin. This landing is the 60th at KSC in the history of the Shuttle program.

  12. Does Kutta lift exist on a vortex ring in a uniform cross flow?

    NASA Astrophysics Data System (ADS)

    Lim, T. T.; Lua, K. B.; Thet, K.

    2008-05-01

    Past works [Y. K. Chang and A. D. Vakili, Phys. Fluids 7, 1583 (1995); R. Sau and K. Mahesh, AIAA Paper No. 2007-1316] show that a vortex ring ejected normal to a cross flow tilts and deforms as it propagates downstream, and they attribute this phenomenon to the Kutta lift or Magnus effect. Here, we show through a controlled experiment that there is no physical evidence of the existence of a Kutta lift when a fully developed vortex ring is exposed to a uniform cross flow. The observed phenomenon could be attributed to the modification of vorticity distribution of the vortex core due to the combined effect of the cross flow itself and the entrainment of boundary layer material during the formation of vortex ring.

  13. Rarefaction Effects in Hypersonic Aerodynamics

    NASA Astrophysics Data System (ADS)

    Riabov, Vladimir V.

    2011-05-01

    The Direct Simulation Monte-Carlo (DSMC) technique is used for numerical analysis of rarefied-gas hypersonic flows near a blunt plate, wedge, two side-by-side plates, disk, torus, and rotating cylinder. The role of various similarity parameters (Knudsen and Mach numbers, geometrical and temperature factors, specific heat ratios, and others) in aerodynamics of the probes is studied. Important kinetic effects that are specific for the transition flow regime have been found: non-monotonic lift and drag of plates, strong repulsive force between side-by-side plates and cylinders, dependence of drag on torus radii ratio, and the reverse Magnus effect on the lift of a rotating cylinder. The numerical results are in a good agreement with experimental data, which were obtained in a vacuum chamber at low and moderate Knudsen numbers from 0.01 to 10.

  14. Multitime correlation functions in nonclassical stochastic processes

    NASA Astrophysics Data System (ADS)

    Krumm, F.; Sperling, J.; Vogel, W.

    2016-06-01

    A general method is introduced for verifying multitime quantum correlations through the characteristic function of the time-dependent P functional that generalizes the Glauber-Sudarshan P function. Quantum correlation criteria are derived which identify quantum effects for an arbitrary number of points in time. The Magnus expansion is used to visualize the impact of the required time ordering, which becomes crucial in situations when the interaction problem is explicitly time dependent. We show that the latter affects the multi-time-characteristic function and, therefore, the temporal evolution of the nonclassicality. As an example, we apply our technique to an optical parametric process with a frequency mismatch. The resulting two-time-characteristic function yields full insight into the two-time quantum correlation properties of such a system.

  15. Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories. Aerospace Nuclear Safety Program

    SciTech Connect

    Sharbaugh, R.C.

    1992-03-23

    Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth`s atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.

  16. Geometrical Optics of Beams with Vortices: Berry Phase and Orbital Angular Momentum Hall Effect

    SciTech Connect

    Bliokh, Konstantin Yu.

    2006-07-28

    We consider propagation of a paraxial beam carrying the spin angular momentum (polarization) and intrinsic orbital angular momentum (IOAM) in a smoothly inhomogeneous isotropic medium. It is shown that the presence of IOAM can dramatically enhance and rearrange the topological phenomena that previously were considered solely in connection to the polarization of transverse waves. In particular, the appearance of a new type of Berry phase that describes the parallel transport of the beam structure along a curved ray is predicted. We derive the ray equations demonstrating the splitting of beams with different values of IOAM. This is the orbital angular momentum Hall effect, which resembles the Magnus effect for optical vortices. Unlike the spin Hall effect of photons, it can be much larger in magnitude and is inherent to waves of any nature. Experimental means to detect the phenomena are discussed.

  17. Numerical calculations of the driving force on an Abrikosov vortex

    NASA Astrophysics Data System (ADS)

    Chen, D.-X.; Pardo, E.; Sanchez, A.

    2010-05-01

    The driving force on an Abrikosov vortex is calculated numerically from the London equation and involved energies for a vortex perpendicular to the screening current near the surface of a superconductor. Compared with previous analytical derivation of the total force, the partial magnetic, kinematic, and external forces are also obtained so that the nature of the driving force may be deeply discussed. It is shown that the force is neither a Lorentz force nor a Magnus force as often believed and that in order to get a correct result, the image effects and the work done by the applied field must be taken into account. A name of London force is suggested for the driving force. A deep understanding of the nature of the driving force on Abrikosov vortices may also be important in the study of vortex pinning and dynamics in type-II superconductors.

  18. Comparing the dynamics of skyrmions and superconducting vortices

    NASA Astrophysics Data System (ADS)

    Olson Reichhardt, C. J.; Lin, S. Z.; Ray, D.; Reichhardt, C.

    2014-08-01

    Vortices in type-II superconductors have attracted enormous attention as ideal systems in which to study nonequilibrium collective phenomena, since the self-ordering of the vortices competes with quenched disorder and thermal effects. Dynamic effects found in vortex systems include depinning, nonequilibrium phase transitions, creep, structural order-disorder transitions, and melting. Understanding vortex dynamics is also important for applications of superconductors which require the vortices either to remain pinned or to move in a controlled fashion. Recently, topological defects called skyrmions have been realized experimentally in chiral magnets. Here we highlight similarities and differences between skyrmion dynamics and vortex dynamics. Many of the previous ideas and experimental setups that have been applied to superconducting vortices can also be used to study skyrmions. We also discuss some of the differences between the two systems, such as the potentially large contribution of the Magnus force in the skyrmion system that can dramatically alter the dynamics and transport properties.

  19. Static and Dynamical Properties of Antiferromagnetic Skyrmions in the Presence of Applied Current and Temperature

    NASA Astrophysics Data System (ADS)

    Barker, Joseph; Tretiakov, Oleg A.

    2016-04-01

    Skyrmions are topologically protected entities in magnetic materials which have the potential to be used in spintronics for information storage and processing. However, Skyrmions in ferromagnets have some intrinsic difficulties which must be overcome to use them for spintronic applications, such as the inability to move straight along current. We show that Skyrmions can also be stabilized and manipulated in antiferromagnetic materials. An antiferromagnetic Skyrmion is a compound topological object with a similar but of opposite sign spin texture on each sublattice, which, e.g., results in a complete cancellation of the Magnus force. We find that the composite nature of antiferromagnetic Skyrmions gives rise to different dynamical behavior due to both an applied current and temperature effects.

  20. Quantum vortex dynamics in two-dimensional neutral superfluids

    SciTech Connect

    Wang, C.-C. Joseph; Duine, R. A.; MacDonald, A. H.

    2010-01-15

    We derive an effective action for the vortex-position degree of freedom in a superfluid by integrating out condensate phase- and density-fluctuation environmental modes. When the quantum dynamics of environmental fluctuations is neglected, we confirm the occurrence of the vortex Magnus force and obtain an expression for the vortex mass. We find that this adiabatic approximation is valid only when the superfluid droplet radius R, or the typical distance between vortices, is very much larger than the coherence length xi. We go beyond the adiabatic approximation numerically, accounting for the quantum dynamics of environmental modes and capturing their dissipative coupling to condensate dynamics. For the case of an optical-lattice superfluid, we demonstrate that vortex motion damping can be adjusted by tuning the ratio between the tunneling energy J and the on-site interaction energy U. We comment on the possibility of realizing vortex-Landau-level physics.

  1. Transformation of the vector part of the 4-momentum in the Dirac equation and in Maxwell's equations in Majorana form for chiral media

    NASA Astrophysics Data System (ADS)

    Sadykov, N. R.

    2011-03-01

    It is suggested to extend the results obtained for Maxwell's equations in Majorana form (spin-1 particles) for spin particles with a half-integer spin and a nonzero mass. It is shown that in an unbounded "chiral medium" (twisted media) the degeneration existing between particles of different helicities is removed. For ultrarelativistic particles, an analog to the inverse optical Magnus effect follows where the effect is determined by the chirality of the medium. From the inverse scattering problem for the transforms under consideration it follows that the amplitude of the wave function of a particle in a chiral medium can vary with time according to a linear law (for example, the process of neutrino (antineutrino) production or annihilation), and the parameters of the medium satisfy the evolution equation.

  2. A brief summary of the attempts to develop large wind-electric generating systems in the U.S.

    NASA Technical Reports Server (NTRS)

    Savino, J. M.

    1974-01-01

    Interest in developing large wind-electric generating systems in the United States was stimulated primarily by one man, Palmer C. Putnam. He was responsible for the construction of the largest wind-power system ever built - the 1250 kilowatt Smith-Putnam wind-electric plant. The existence of this system prompted the U.S. Federal Power Commission to investigate the potential of using the winds as a source energy. Also, in 1933 prior to Putnam's effort, there was an abortive attempt by J. D. Madaras to develop a wind system based on the Magnus effect. These three projects comprise the only serious efforts in America to develop large wind driven plants. In this paper, the history of each project is briefly described. Also discussed are some of the reasons why wind energy was not seriously considered as a major source of energy for the U.S.

  3. Semiclassical Dynamics of Electron Wave Packet States with Phase Vortices

    SciTech Connect

    Bliokh, Konstantin Yu.; Bliokh, Yury P.; Savel'ev, Sergey; Nori, Franco

    2007-11-09

    We consider semiclassical higher-order wave packet solutions of the Schroedinger equation with phase vortices. The vortex line is aligned with the propagation direction, and the wave packet carries a well-defined orbital angular momentum (OAM) ({Dirac_h}/2{pi})l (l is the vortex strength) along its main linear momentum. The probability current coils around the momentum in such OAM states of electrons. In an electric field, these states evolve like massless particles with spin l. The magnetic-monopole Berry curvature appears in momentum space, which results in a spin-orbit-type interaction and a Berry/Magnus transverse force acting on the wave packet. This brings about the OAM Hall effect. In a magnetic field, there is a Zeeman interaction, which, can lead to more complicated dynamics.

  4. Edge tunneling of vortices in superconducting thin films

    SciTech Connect

    Iengo, R. |; Jug, G. |

    1996-11-01

    We investigate the phenomenon of the decay of a supercurrent due to the zero-temperature quantum tunneling of vortices from the edge in a thin superconducting film in the absence of an external magnetic field. An explicit formula is derived for the tunneling rate of vortices, which are subject to the Magnus force induced by the supercurrent, through the Coulomb-like potential barrier binding them to the film{close_quote}s edge. Our approach ensues from the nonrelativistic version of a Schwinger-type calculation for the decay of the two-dimensional vacuum previously employed for describing vortex-antivortex pair nucleation in the bulk of the sample. In the dissipation-dominated limit, our explicit edge-tunneling formula yields numerical estimates which are compared with those obtained for bulk nucleation to show that both mechanisms are possible for the decay of a supercurrent. {copyright} {ital 1996 The American Physical Society.}

  5. A brief summary of the attempts to develop large wind-electric generating systems in the US

    NASA Technical Reports Server (NTRS)

    Savino, J. M.

    1974-01-01

    Interest in developing large wind-electric generating systems in the United States was simulated primarily by one man, Palmer C. Putnam. He was responsible for the construction of the 1250 kilowatt Smith-Putnam wind-electric plant. The existence of this system prompted the U. S. Federal Power Commission to investigate the potential of using the winds as a source energy. Also, in 1933 prior to Putnam's effort, there was an abortive attempt by J. D. Madaras to develop a wind system based on the Magnus effect. These three projects comprise the only serious efforts in America to develop large wind driven plants. In this paper the history of each project is briefly described. Also discussed are some of the reasons why wind energy was not seriously considered as a major source of energy for the U. S.

  6. Self-propulsion of a body with rigid surface and variable coefficient of lift in a perfect fluid

    NASA Astrophysics Data System (ADS)

    Ramodanov, Sergey M.; Tenenev, Valentin A.; Treschev, Dmitry V.

    2012-11-01

    We study the system of a 2D rigid body moving in an unbounded volume of incompressible, vortex-free perfect fluid which is at rest at infinity. The body is equipped with a gyrostat and a so-called Flettner rotor. Due to the latter the body is subject to a lifting force (Magnus effect). The rotational velocities of the gyrostat and the rotor are assumed to be known functions of time (control inputs). The equations of motion are presented in the form of the Kirchhoff equations. The integrals of motion are given in the case of piecewise continuous control. Using these integrals we obtain a (reduced) system of first-order differential equations on the configuration space. Then an optimal control problem for several types of the inputs is solved using genetic algorithms.

  7. STS-112 crew in front of Launch Pad 39B before launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - STS-112 Commander Jeffrey S. Ashby poses in front of Launch Pad 39B during a tour of Kennedy Space Center prior to launch. Also on the tour were the other members of the crew including Pilot Pamela Ann Melroy and Mission Speci alists David A. Wolf, Sandra H. Magnus, Piers J. Sellers, and Fyodor N. Yurchikhin of the Russian Space Agency. The launch of Space Shuttle Atlantis was postponed today to no earlier than Thursday, Oct. 3, while weather forecasters and the mission managem ent team assess the possible effect Hurricane Lili may have on the Mission Control Center located at the Lyndon B. Johnson Space Center in Houston, Texas.

  8. Vortex loops: Are they always doomed to die

    SciTech Connect

    Ben-Ya'acov, U. )

    1995-03-15

    The effective equations of motion of relativistic strings in material media are derived and applied to moving rings with a time-dependent radius. The equations contain the Magnus force, due to the motion of the ring relative to the medium, whose eventual effect is the possible stabilization of the ring against shrinking. A constant solution is identified, and small fluctuations around it are bound, demonstrating the stability of the solution. If the string loops created in the cosmological cosmic string scenario interact via this mechanism with a formed-up Higgs particle condensate, then the stabilizing velocities are [similar to][delta][sub loop]/[ital R][sub loop], and the overall effect of this phenomenon is to stabilize large loops and reduce the general disappearance rate of the string loops.

  9. STS-112 crew with President of Ajara in Georgia (Russia)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- In the Operations and Checkout Building, Aslan Abashidze (right), President of the Autonomous Republic of Ajara in Georgia (Russia), visits with the STS-112 crew. From left, they are Mission Specialist Piers J. Sellers; Pilot Pamela Ann Melroy; Mission Specialist Fyodor N. Yurchikhin, a cosmonaut with the Russian Space Agency; Mission Specialist Sandra H. Magnus; and CommanderJeffrey S. Ashby. Mission Specialist David A. Wolf, not pictured, is also a member of the crew. The crew is awaiting launch on mission STS-112 to the International Space Station aboard Space Shuttle Atlantis. The launch has been postponed to no earlier than Monday, Oct. 7, so that the Mission Control Center, located at the Lyndon B. Johnson Space Center in Houston, Texas, can be secured and protected from potential storm impacts from Hurricane Lili.

  10. Pharmacogenomics: from cell to clinic (Part 1).

    PubMed

    Siest, Gérard; Medeiros, Rui; Melichar, Bohuslav; Stathopoulou, Maria; Van Schaik, Ron H N; Cacabelos, Ramon; Abt, Peter Meier; Monteiro, Carolino; Gurwitz, David; Queiroz, Jao; Mota-Filipe, Helder; Ndiaye, Ndieye Coumba; Visvikis-Siest, Sophie

    2014-04-01

    The second international European Society of Pharmacogenomics and Theranostics (ESPT) conference was organized in Lisbon, Portugal, and attracted 250 participants from 37 different countries. The participants could listen to 50 oral presentations, participate in five lunch symposia and were able to view 83 posters and an exhibition. The first part of this Conference Scene will focus on the pharmacogenomics and biomarkers used in medical oncology, and in particular solid tumors. In addition, this article covers the two keynote conference introductory lectures by Ann K Daly and Magnus Ingelman-Sundberg. The second part of this article will discuss the clinical implementation of pharmacogenomic tests; the role of transports and pharmacogenomics; how stem cells and other new tools are helping the development of pharmacogenomics and drug discovery; and an update on the clinical translation of pharmacogenomics to personalized medicine. Part two of this Conference Scene will be featured in the next issue of Pharmacogenomics. PMID:24798716

  11. Static and Dynamical Properties of Antiferromagnetic Skyrmions in the Presence of Applied Current and Temperature.

    PubMed

    Barker, Joseph; Tretiakov, Oleg A

    2016-04-01

    Skyrmions are topologically protected entities in magnetic materials which have the potential to be used in spintronics for information storage and processing. However, Skyrmions in ferromagnets have some intrinsic difficulties which must be overcome to use them for spintronic applications, such as the inability to move straight along current. We show that Skyrmions can also be stabilized and manipulated in antiferromagnetic materials. An antiferromagnetic Skyrmion is a compound topological object with a similar but of opposite sign spin texture on each sublattice, which, e.g., results in a complete cancellation of the Magnus force. We find that the composite nature of antiferromagnetic Skyrmions gives rise to different dynamical behavior due to both an applied current and temperature effects. PMID:27104724

  12. A novel series of pyrazolylpiperidine N-type calcium channel blockers.

    PubMed

    Subasinghe, Nalin L; Wall, Mark J; Winters, Michael P; Qin, Ning; Lubin, Mary Lou; Finley, Michael F A; Brandt, Michael R; Neeper, Michael P; Schneider, Craig R; Colburn, Raymond W; Flores, Christopher M; Sui, Zhihua

    2012-06-15

    Selective blockers of the N-type calcium channel have proven to be effective in animal models of chronic pain. However, even though intrathecally delivered synthetic ω-conotoxin MVIIA from Conus magnus (ziconotide [Prialt®]) has been approved for the treatment of chronic pain in humans, its mode of delivery and narrow therapeutic window have limited its usefulness. Therefore, the identification of orally active, small-molecule N-type calcium channel blockers would represent a significant advancement in the treatment of chronic pain. A novel series of pyrazole-based N-type calcium channel blockers was identified by structural modification of a high-throughput screening hit and further optimized to improve potency and metabolic stability. In vivo efficacy in rat models of inflammatory and neuropathic pain was demonstrated by a representative compound from this series. PMID:22608964

  13. STS-112 crew on SLF after landing

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 Pilot Pamela Melroy (left) and Mission Specialist Sandra Magnus (center) talk to Acting Deputy Director JoAnn Morgan (right) after the crew's return to KSC. A flawless landing of Space Shuttle Atlantis completed a 4.5 -million-mile journey to the International Space Station. Other crew members are Commander Jeffrey Ashby and Mission Specialists David Wolf, Fyodor Yurchikhin and Piers Sellers. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11: 43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment.

  14. High efficiency in mode-selective frequency conversion.

    PubMed

    Quesada, Nicolás; Sipe, J E

    2016-01-15

    Frequency conversion (FC) is an enabling process in many quantum information protocols. Recently, it has been observed that upconversion efficiencies in single-photon, mode-selective FC are limited to around 80%. In this Letter, we argue that these limits can be understood as time-ordering corrections (TOCs) that modify the joint conversion amplitude of the process. Furthermore, using a simple scaling argument, we show that recently proposed cascaded FC protocols that overcome the aforementioned limitations act as "attenuators" of the TOCs. This observation allows us to argue that very similar cascaded architectures can be used to attenuate TOCs in photon generation via spontaneous parametric downconversion. Finally, by using the Magnus expansion, we argue that the TOCs, which are usually considered detrimental for FC efficiency, can also be used to increase the efficiency of conversion in partially mode-selective FC. PMID:26766715

  15. Some Aspects of the Physics of Shooting a Basketball

    NASA Astrophysics Data System (ADS)

    Fontanella, John J.

    2006-12-01

    The flight of a basketball is considered.1 Video analysis of the path and spin for several shots was carried out. It is shown that four forces are required to reproduce the trajectory: gravity, buoyancy, the drag force and the Magnus force. The relative contribution of each force is determined. The model is used to evaluate what it is that good shooters do. For a foul shot, the approach speed (speed when the basketball is just above the rim), launch speed, and launch angle were calculated. It is found that the minimum in the approach speed occurs at a launch angle closer to the experimental values for good shooters than does the minimum in the launch speed. This suggests the hoopothesis that a good shooter strives for the “softest” shot. 1. J. J. Fontanella, The Physics of Basketball, The Johns Hopkins University Press, Baltimore, 2006.

  16. New species and records of Burmagomphus Williamson, 1907 (Odonata, Gomphidae) from China.

    PubMed

    Zhang, Hao-Miao; Kosterin, Oleg E; Cai, Qing-Hua

    2015-01-01

    Four new species of Burmagomphus Williamson, 1907 are described from Southwestern China: B. apricus sp. nov. from Xishuangbanna National Nature Reserve, Menglun Town, Xishuangbanna Dai Autonomous Prefecture, Yunnan Province; B. magnus sp. nov. from Huayudong, Nanxi Town, Hekou County, Hani-Yi Autonomous Prefecture of Honghe, Yunnan Province, B. dentatus sp. nov. from Zhangjiang River in Xiaoqikong scenic spot, altitude 400 m, Libo County, Guizhou Province, and B. latescens sp. nov. from Sifangjing, Mengding Town, Gengma County, Lincang City, Yunnan Province. New records of Burmagomphus spp. in China are provided, with B. asahinai and B. williamsoni williamsoni for the first time reported from China. A revised checklist of Burmagomhus spp. of China is provided which includes 14 species. A doubtful record of B. arboreus and relations of the newly described species are discussed. All types are deposited in the Collection of Aquatic Animals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan City, Hubei Province, China. PMID:26250326

  17. Elastohydrodynamics of a free cylinder near a soft wall

    NASA Astrophysics Data System (ADS)

    Mahadevan, L.; Salez, Thomas

    2015-11-01

    We consider the motion of a fluid-immersed negatively buoyant particle in the vicinity of a thin compressible elastic wall. We use scaling arguments to establish different regimes of settling, sliding, rolling and complement these estimates using thin-film lubrication dynamics to determine an asymptotic theory for the sedimentation, sliding, and spinning motions of a cylinder. Numerical integration of the resulting equations confirms our scaling relations and further yields a range of behaviours such as spontaneously oscillations when sliding, lift via a Magnus-like effect, a spin-induced reversal effect, and an unusual sedimentation singularity. Our description also allows us to address a sedimentation-sliding transition that can lead to the particle coasting over very long distances, similar to certain geophysical phenomena.

  18. STS-112 crew talks to media after landing

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The STS-112 crew clown for the camera in front of Atlantis after saying a few words about their 4.5-million-mile journey to the International Space Station. From left are Mission Specialist Sandra Magnus, Pilot Pamela Melroy, Commander Jeffrey Ashby, and Mission Specialists David Wolf, Fyodor Yurchikhin and Piers Sellers. The flawless landing of Space Shuttle Atlantis on Runway 33 at KSC completed the 10 day, 19 hour, 58 minute, 44 second- long mission. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment.

  19. Somatostatin- and enkephalin-like immunoreactivities are frequently colocalized in neurons in the caudal brain stem of rat.

    PubMed

    Millhorn, D E; Hökfelt, T; Terenius, L; Buchan, A; Brown, J C

    1987-01-01

    The medulla oblongata and pons of colchicine treated rats were analyzed with a double-staining technique using mouse monoclonal antibodies to somatostatin and rabbit polyclonal antibodies raised against methionine-enkephalin. Numerous cells reacted with both antisera but cells reacting with only one antiserum were also observed. Double-stained cells were most frequently encountered at all levels of the nucleus tractus solitarii, in a well defined group in the caudal medullary reticular formation, along the lateral ventral surface of the medulla oblongata, dorsolateral to the inferior olive and in the nucleus raphe magnus. These findings provide further examples of coexistence of two peptides and indicate the possibility that somatostatin- and enkephalin-like peptides are co-released. PMID:2887451

  20. STS-112 Atlantis landing at KSC's shuttle landing facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Its drag chute deployed, Space Shuttle Atlantis slows to a stop after touchdown on Runway 33 at the Shuttle Landing Facility, completing the 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment. The returning crew of Atlantis are Commander Jeffrey Ashby, Pilot Pamela Melroy, and Mission Specialists David Wolf, Piers Sellers, Sandra Magnus and Fyodor Yurchikhin. This landing is the 60th at KSC in the history of the Shuttle program. .

  1. Three-loop master integrals for ladder-box diagrams with one massive leg

    NASA Astrophysics Data System (ADS)

    Di Vita, Stefano; Mastrolia, Pierpaolo; Schubert, Ulrich; Yundin, Valery

    2014-09-01

    The three-loop master integrals for ladder-box diagrams with one massive leg are computed from an eighty-five by eighty-five system of differential equations, solved by means of Magnus exponential. The results of the considered box-type integrals, as well as of the tower of vertex- and bubble-type master integrals associated to subtopologies, are given as a Taylor series expansion in the dimensional regulator parameter ɛ = (4 - d)/2. The coefficients of the series are expressed in terms of uniform weight combinations of multiple polylogarithms and transcendental constants up to weight six. The considered integrals enter the next-to-next-to-next-to-leading order virtual corrections to scattering processes like the three-jet production mediated by vector boson decay, V * → jjj, as well as the Higgs plus one-jet production in gluon fusion, pp → Hj.

  2. Antiferromagnetic skyrmions

    NASA Astrophysics Data System (ADS)

    Tretiakov, Oleg; Barker, Joseph

    Skyrmions are topologically protected entities in magnetic materials which have the potential to be used in spintronics for information storage and processing. However, skyrmions in ferromagnets have some intrinsic difficulties which must be overcome to use them for spintronic applications, such as the inability to move straight along current. We show that skyrmions can also be stabilized and manipulated in antiferromagnetic materials. An antiferromagnetic skyrmion is a compound topological object with a similar but of opposite sign spin texture on each sublattice, which e.g. results in a complete cancelation of the Magnus force. We find that the composite nature of antiferromagnetic skyrmions gives rise to different dynamical behavior, both due to an applied current and temperature effects. O.A.T. and J.B. acknowledge support by the Grants-in-Aid for Scientific Research (Nos. 25800184, 25247056, 25220910 and 15H01009) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan and SpinNet.

  3. STS-112 Atlantis landing at KSC's shuttle landing facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- Space Shuttle Atlantis stirs up dust as it touches down on Runway 33 at the Shuttle Landing Facility, completing the 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment. The returning crew of Atlantis are Commander Jeffrey Ashby, Pilot Pamela Melroy, and Mission Specialists David Wolf, Piers Sellers, Sandra Magnus and Fyodor Yurchikhin. This landing is the 60th at KSC in the history of the Shuttle program. .

  4. Direct and indirect pathways to lamina I in the medulla oblongata and spinal cord of the cat

    NASA Technical Reports Server (NTRS)

    Holstege, Gert

    1988-01-01

    The pathways to lamina I in the medulla oblongata and spinal cord of the cat were traced using horse-radish-peroxidase (HRP) and autoradiographic techniques. The HRP results indicated that several neuronal cell groups in the brain stem and hypothalamus project to the spinal cord throughout its total length. The autoradiographic tracing results demonstrated that the strongest projections to lamina I are derived from the following four areas: the caudal nucleus raphe magnus (NRM), the ventral part of the caudal pontine and NRM, the contralaterally projecting lateral pontine or paralemniscal tegmentum, and the paraventricular nucleus of the hypothalamus. In addition, a limited, especially at lumbosacral levels, distinct projection to lamina I was found to originate in the most caudal part of the medullary tegmentum.

  5. STS-112 Atlantis landing at KSC's shuttle landing facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - A fire rescue truck stands by for safety reasons as Space Shuttle Atlantis slows to a stop on Runway 33 at the Shuttle Landing Facility, completing the 4.5-million-mile journey to the International Space Station. Main gear touchdown occurred at 11:43:40 a.m. EDT; nose gear touchdown at 11:43:48 a.m.; and wheel stop at 11:44:35 a.m. Mission elapsed time was 10:19:58:44. Mission STS-112 expanded the size of the Station with the addition of the S1 truss segment. The returning crew of Atlantis are Commander Jeffrey Ashby, Pilot Pamela Melroy, and Mission Specialists David Wolf, Piers Sellers, Sandra Magnus and Fyodor Yurchikhin. This landing is the 60th at KSC in the history of the Shuttle program. .

  6. Guided current-induced skyrmion motion in 1D potential well

    PubMed Central

    Purnama, I.; Gan, W. L.; Wong, D. W.; Lew, W. S.

    2015-01-01

    Magnetic skyrmions are particle-like magnetization configurations which can be found in materials with broken inversion symmetry. Their topological nature allows them to circumvent around random pinning sites or impurities as they move within the magnetic layer, which makes them interesting as information carriers in memory devices. However, when the skyrmion is driven by a current, a Magnus force is generated which leads to the skyrmion moving away from the direction of the conduction electron flow. The deflection poses a serious problem to the realization of skyrmion-based devices, as it leads to skyrmion annihilation at the film edges. Here, we show that it is possible to guide the movement of the skyrmion and prevent it from annihilating by surrounding and compressing the skyrmion with strong local potential barriers. The compressed skyrmion receives higher contribution from the spin transfer torque, which results in the significant increase of the skyrmion speed. PMID:26024469

  7. STS-112 Flight Day 4 Highlights

    NASA Astrophysics Data System (ADS)

    2002-10-01

    On the fourth day of STS-112, its crew (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Mission Specialist; Piers Sellers, Mission Specialist; Sandra Magnus, Mission Specialist; Fyodor Yurchikhin, Mission Specialist) onboard Atlantis and the Expedition 5 crew (Valery Korzun, Commander; Peggy Whitson, Flight Engineer; Sergei Treschev, Flight Engineer) onboard the International Space Station (ISS) are seen preparing for the installation of the S1 truss structure. Inside the Destiny Laboratory Module, Korzun and other crewmembers are seen as they busily prepare for the work of the day. Sellers dons an oxygen mask and uses an exercise machine in order to purge the nitrogen from his bloodstream, in preparation for an extravehicular activity (EVA). Whitson uses the ISS's Canadarm 2 robotic arm to grapple the S1 truss and remove it from Atlantis' payload bay, with the assistance of Magnus. Using the robotic arm, Whitson slowly maneuvers the 15 ton truss structure into alignment with its attachment point on the starboard side of the S0 truss structure, where the carefully orchestrated mating procedures take place. There is video footage of the entire truss being rotated and positioned by the arm, and ammonia tank assembly on the structure is visible, with Earth in the background. Following the completion of the second stage capture, the robotic arm is ungrappled from truss. Sellers and Wolf are shown exiting the the Quest airlock hatch to begin their EVA. They are shown performing a variety of tasks on the now attached S1 truss structure, including work on the Crew Equipment Translation Cart (CETA), the S-band Antenna Assembly, and umbilical cables that provide power and remote operation capability to cameras. During their EVA, they are shown using a foot platform on the robotic arm. Significant portions of their activities are shown from the vantage of helmet mounted video cameras. The video closes with a final shot of the ISS and its new S1 truss.

  8. STS-112 Flight Day 4 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On the fourth day of STS-112, its crew (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Mission Specialist; Piers Sellers, Mission Specialist; Sandra Magnus, Mission Specialist; Fyodor Yurchikhin, Mission Specialist) onboard Atlantis and the Expedition 5 crew (Valery Korzun, Commander; Peggy Whitson, Flight Engineer; Sergei Treschev, Flight Engineer) onboard the International Space Station (ISS) are seen preparing for the installation of the S1 truss structure. Inside the Destiny Laboratory Module, Korzun and other crewmembers are seen as they busily prepare for the work of the day. Sellers dons an oxygen mask and uses an exercise machine in order to purge the nitrogen from his bloodstream, in preparation for an extravehicular activity (EVA). Whitson uses the ISS's Canadarm 2 robotic arm to grapple the S1 truss and remove it from Atlantis' payload bay, with the assistance of Magnus. Using the robotic arm, Whitson slowly maneuvers the 15 ton truss structure into alignment with its attachment point on the starboard side of the S0 truss structure, where the carefully orchestrated mating procedures take place. There is video footage of the entire truss being rotated and positioned by the arm, and ammonia tank assembly on the structure is visible, with Earth in the background. Following the completion of the second stage capture, the robotic arm is ungrappled from truss. Sellers and Wolf are shown exiting the the Quest airlock hatch to begin their EVA. They are shown performing a variety of tasks on the now attached S1 truss structure, including work on the Crew Equipment Translation Cart (CETA), the S-band Antenna Assembly, and umbilical cables that provide power and remote operation capability to cameras. During their EVA, they are shown using a foot platform on the robotic arm. Significant portions of their activities are shown from the vantage of helmet mounted video cameras. The video closes with a final shot of the ISS and its new S1 truss.

  9. Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework

    SciTech Connect

    Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A. E-mail: mcgl@qb.ffyb.uba.ar; Lebrero, Mariano C. González E-mail: mcgl@qb.ffyb.uba.ar

    2014-04-28

    This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.

  10. Shapiro steps for skyrmion motion on a washboard potential with longitudinal and transverse ac drives

    NASA Astrophysics Data System (ADS)

    Reichhardt, C.; Reichhardt, C. J. Olson

    2015-12-01

    We numerically study the behavior of two-dimensional skyrmions in the presence of a quasi-one-dimensional sinusoidal substrate under the influence of externally applied dc and ac drives. In the overdamped limit, when both dc and ac drives are aligned in the longitudinal direction parallel to the direction of the substrate modulation, the velocity-force curves exhibit classic Shapiro step features when the frequency of the ac drive matches the washboard frequency that is dynamically generated by the motion of the skyrmions over the substrate, similar to previous observations in superconducting vortex systems. In the case of skyrmions, the additional contribution to the skyrmion motion from a nondissipative Magnus force shifts the location of the locking steps to higher dc drives, and we find that the skyrmions move at an angle with respect to the direction of the dc drive. For a longitudinal dc drive and a perpendicular or transverse ac drive, the overdamped system exhibits no Shapiro steps; however, when a finite Magnus force is present, we find pronounced transverse Shapiro steps along with complex two-dimensional periodic orbits of the skyrmions in the phase-locked regimes. Both the longitudinal and transverse ac drives produce locking steps whose widths oscillate with increasing ac drive amplitude. We examine the role of collective skyrmion interactions and find that additional fractional locking steps occur for both longitudinal and transverse ac drives. At higher skyrmion densities, the system undergoes a series of dynamical order-disorder transitions, with the skyrmions forming a moving solid on the phase locking steps and a fluctuating dynamical liquid in regimes between the steps.

  11. Gram-Positive Anaerobic Cocci

    PubMed Central

    Murdoch, D. A.

    1998-01-01

    Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of organisms defined by their morphological appearance and their inability to grow in the presence of oxygen; most clinical isolates are identified to species in the genus Peptostreptococcus. GPAC are part of the normal flora of all mucocutaneous surfaces and are often isolated from infections such as deep organ abscesses, obstetric and gynecological sepsis, and intraoral infections. They have been little studied for several reasons, which include an inadequate classification, difficulties with laboratory identification, and the mixed nature of the infections from which they are usually isolated. Nucleic acid studies indicate that the classification is in need of radical revision at the genus level. Several species of Peptostreptococcus have recently been described, but others still await formal recognition. Identification has been based on carbohydrate fermentation tests, but most GPAC are asaccharolytic and use the products of protein degradation for their metabolism; the introduction of commercially available preformed enzyme kits affords a physiologically more appropriate method of identification, which is simple and relatively rapid and can be used in routine diagnostic laboratories. Recent reports have documented the isolation in pure culture of several species, notably Peptostreptococcus magnus, from serious infections. Studies of P. magnus have elucidated several virulence factors which correlate with the site of infection, and reveal some similarities to Staphylococcus aureus. P. micros is a strongly proteolytic species; it is increasingly recognized as an important pathogen in intraoral infections, particularly periodontitis, and mixed anaerobic deep-organ abscesses. Comparison of antibiotic susceptibility patterns reveals major differences between species. Penicillins are the antibiotics of choice, although some strains of P. anaerobius show broad-spectrum β-lactam resistance. PMID:9457430

  12. Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework

    NASA Astrophysics Data System (ADS)

    Morzan, Uriel N.; Ramírez, Francisco F.; Oviedo, M. Belén; Sánchez, Cristián G.; Scherlis, Damián A.; Lebrero, Mariano C. González

    2014-04-01

    This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.

  13. A review of the genus Neoechinorhynchus (Acanthocephala:Neoechinorhynchidae) from Australia with the description of two new species.

    PubMed

    Smales, L R

    2013-12-01

    Abstract Eight species of Neoechinorhynchus were reported from Australian waters. Neoechinorhynchus vittiformis n. sp. is described from Eleutheronema tetradactylum (Shaw). It can be distinguished from all its congeners by the following combination of characters: long cylindrical trunk without cuticular plaques, globular proboscis, proboscis armature with the anterior circle of hooks larger with simple roots and the middle and posterior hooks the same size and smaller, short neck, lemnisci nearly equal, almost reaching the anterior testis which is more than half the length of the posterior testis. Neoechinorhynchus (Neoechinorhynchus) bryanti n. sp., described from Liza subviridis (Valenciennes), also with an elongated trunk, can be distinguished from its congeners by the combination of a wider anterior trunk without cuticular plaques, a relatively long conical neck, a subglobular proboscis having anterior hooks with manubria, the hooks becoming gradually smaller posteriorly, the lemnisci not reaching level of testes and the anterior testis being longer than posterior testis. Neoechinorhynchus sp. resembled Neoechinorhynchus aldrichettae Edmonds, 1971 but had a rectangular-shaped proboscis with larger anterior hooks. New host and locality records were presented for N. aldrichettae, Neoechinorhynchus (Hebesoma) agilis (Rudolphi) and Neoechinorhynchus tylosuri Yamaguti, 1939 . No additional specimens of either Neoechinorhynchus ningalooensis Pichelin and Cribb, 2001 or the species inquirenda, Neoechinorhynchus magnus Southwell and Macfie, 1925, were available for study. Of the 8 putative species listed here, 5 (N. [N.] bryanti, N. magnus , N. ningalooensis, N. vittiformis, and Neoechinorhynchus sp.) are endemic to Australian waters. By comparison with the North American fauna the Australian fauna was considered impoverished. The morphological and zoogeographical similarities within the group of 8 long, slender neoechinorhynchid species found in the African, Indo

  14. Ambient Seismic Noise Tomography of Southern Norway

    NASA Astrophysics Data System (ADS)

    Köhler, Andreas; Weidle, Christian; Maupin, Valerie

    2010-05-01

    The noise cross-correlation technique is especially useful in regions like southern Norway since local seismicity is rare and teleseismic records are not able to resolve the upper crust. Within the TopoScandiaDeep project, which aims to investigate the relation between surface topography and lithosphere-asthenosphere structure, we process seismic broadband data from the temporary MAGNUS network in Southern Norway. The receivers were recording 20 months of continuous data between September 2006 and June 2008. Additionally, permanent stations of the National Norwegian Seismic Network, NORSAR and GSN stations in the region are used. After usual preprocessing steps (filtering, prewhitening, temporal normalization), we compute 820 cross-correlation functions from 41 receivers for three month time windows. Evaluation of the azimuthal and temporal variation of signal to noise ratios and f-k analysis of NORSAR array data shows that the dominant propagation direction of seismic noise is south-west to north, corresponding well to the Norwegian coast line. During summer months, the signal to noise ratios decrease and the azimuthal distribution becomes smoother. Time-frequency analysis is applied to measure Rayleigh and Love wave group velocity dispersion curves between each station pair for each three-month correlation stack. The mean and variance of all dispersion curves is computed for each path. After rejection of low-quality data using a signal to noise ratio, minimum wavelength and velocity variance criterion, we obtain a large number of reliable velocity estimates (about 600) for periods between 2 and 15 seconds, which we invert for group velocity maps at respective periods. At all inverted periods, we find positive and negative velocity anomalies for Rayleigh and Love waves that correlate very well with local surface geology. While higher velocities (+5%) can be associated with the Caledonian nappes in the central part of southern Norway, the Oslo Graben is reflected

  15. Crustal structure, and topographic relief in the high southern Scandes, Norway

    NASA Astrophysics Data System (ADS)

    Stratford, W.; Thybo, H.; Frassetto, A.

    2010-05-01

    Resolving the uplift history of southern Norway is hindered by the lack of constraint available from the geologic record. Sediments that often contain information of burial and uplift history have long since been stripped from the onshore regions in southern Norway, and geophysical, dating methods and geomorphological studies are the remaining means of unraveling uplift history. New constraints on topographic evolution and uplift in southern Norway have been added by a recent crustal scale refraction project. Magnus-Rex (Mantle investigation of Norwegian uplift Structure, refraction experiment) recorded three ~400 km long active source seismic profiles across the high southern Scandes Mountains. The goal of the project is to determine crustal thickness and establish whether these mountains are supported at depth by a crustal root or by other processes. The southern Scandes Mountains were formed during the Caledonian Orogeny around 440 Ma. These mountains, which reach elevations of up to ~2.5 km, are comprised of one or more palaeic (denudation) surfaces of rolling relief that are incised by fluvial and glacial erosion. Extreme vertical glacial incision of up to 1000 m cuts into the surfaces in the western fjords, while the valleys of eastern Norway are more fluvial in character. Climatic controls on topography here are the Neogene - Recent effects of rebound due to removal of the Fennoscandian ice sheet and isostatic rebound due to incisional erosion. However, unknown tectonic uplift mechanisms may also be in effect, and separating the tectonic and climate-based vertical motions is often difficult. Sediment and rock has been removed by the formation of the palaeic surfaces and uplift measurements cannot be directly related to present elevations. Estimates so far have indicated that rebound due to incisional erosion has a small effect of ~500 m on surface elevation. Results from Magnus-Rex indicate the crust beneath the high mountains is up to 40 km thick. This

  16. Crustal composition in southern Norway from active and passive source seismology

    NASA Astrophysics Data System (ADS)

    Stratford, W. R.; Frassetto, A. M.; Thybo, H.

    2010-12-01

    Crustal composition and structure beneath the Fennoscandian shield are highly variable due to the method of crustal accretion and the long history of extensional and compressional tectonics. In southern Norway, the Moho and crust are inferred to be the youngest of the shield, however, it is likely that a large discrepancy between crustal age and Moho age exists beneath the high southern Scandes where the Caledonian orogeny was in effect and beneath the Oslo Graben where 60 million years of rifting and magmatism has altered the crust. Crustal structure in southern Norway was targeted with a multi-disciplinary seismic study (Magnus-Rex - Mantle investigations of Norwegian uplift Structure). Three ~400 km long active source seismic profiles across the southern Norway and a region wide array of broadband seismometers were deployed. P and S-wave arrivals were recorded in the Magnus-Rex project, from which Poisson ratios for the crust in southern Norway are calculated from both active source profiling and receiver functions. Unusually strong S-wave arrivals allow rare insight into crustal Poisson’s ratio structure, within crustal layers, that is not normally available from active source data and are usually determined by earthquake tomography studies where only bulk crustal values are available. An average Poisson’s ratio of 0.25 is calculated for the crust in southern Norway, suggesting it is predominantly of felsic-intermediate composition and lacks any significant mafic lower crust. This differs significantly from the adjacent crust in the Svecofennian domain of the Fennoscandian shield where Moho depths reach ~50 km and an up to 20 km thick mafic lower crust is present. The vast difference in Moho depths in the Fennoscandian shield are, therefore, mostly due to the variation in thickness of the high Vp lower crust. Estimates of crustal composition and the effect of Magma intrusion within the Oslo Graben, and possible delamination of the lowermost crust beneath

  17. Moho depth and age in southern Norway

    NASA Astrophysics Data System (ADS)

    Stratford, W.; Thybo, H.

    2010-05-01

    Moho ages beneath the Fennoscandian shield are highly variable due to the method of crustal accretion and to the long history of extensional and compressional tectonics. In southern Norway, the Moho and crust are inferred to be the youngest of the shield, however, it is likely that a large discrepancy between crustal age and Moho age exists beneath the high southern scandes where the Caledonian orogeny was in effect. Moho structure in southern Norway was targeted recently with a seismic refraction study (Magnus-Rex - Mantle investigations of Norwegian uplift Structure, refraction experiment). Three ~400 km long active source seismic profiles across the high southern Scandes Mountains, the youngest section of the Fennoscandian shield were recorded. Moho depths beneath the high mountains are 36-40 km, thinning towards the Atlantic Margin and the Oslo graben. A new Moho depth map is constructed for southern Norway by compiling new depth measurements with previous refraction Moho measurements. Gaining better constraint on Moho depths in this area is timely, as debate over the source of support for the mountains has provided the impetus for a new focus project, TopoScandesdeep, to find the depth and mechanisms of compensation. P and S-wave arrivals were recorded in the Magnus-Rex project, from which Poisson ratios for the crust in southern Norway are calculated. Unusually strong S-wave arrivals allow rare insight into crustal Poisson's ratio structure that is not normally available from active source data and are usually determined by earthquake tomography studies where only bulk crustal values are available. An average Poisson's ratio of 0.25 is calculated for the crust in southern Norway, suggesting it is predominantly of felsic-intermediate composition and lacks any significant mafic lower crust. This differs significantly from the adjacent crust in the Svecofennian domain of the Fennoscandian shield where Moho depths reach ~50 km and an up to 20 km thick mafic lower

  18. Fluid Mechanics of Cricket and Tennis Balls

    NASA Astrophysics Data System (ADS)

    Mehta, Rabindra D.

    2009-11-01

    Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports. The main interest is in the fact that the ball can often deviate from its initial straight path, resulting in a curved, or sometimes an unpredictable, flight path. It is particularly fascinating that that not all the parameters that affect the flight of a ball are always under human influence. Lateral deflection in flight, commonly known as swing, swerve or curve, is well recognized in cricket and tennis. In tennis, the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight, which gives rise to what is commonly known as the Magnus effect. It is now well recognized that the aerodynamics of sports balls are strongly dependent on the detailed development and behavior of the boundary layer on the ball's surface. A side force, which makes a ball curve through the air, can also be generated in the absence of the Magnus effect. In one of the cricket deliveries, the ball is released with the seam angled, which trips the laminar boundary layer into a turbulent state on that side. The turbulent boundary layer separates relatively late compared to the laminar layer on the other side, thereby creating a pressure difference and hence side force. The fluid mechanics of a cricket ball become very interesting at the higher Reynolds numbers and this will be discussed in detail. Of all the round sports balls, a tennis ball has the highest drag coefficient. This will be explained in terms of the contribution of the ``fuzz" drag and how that changes with Reynolds number and ball surface wear. It is particularly fascinating that, purely through historical accidents, small disturbances on the ball surface, such as the stitching on cricket balls and the felt cover on tennis balls are all about the right size to affect boundary layer transition and development in the Reynolds numbers of interest. The fluid

  19. Dreissena polymorpha Pall. postveligers in submersed macrophyte beds of Put-in-Bay, Ohio, as related to rate and density of settlement, macrophyte preference, water depth, and position within beds

    SciTech Connect

    Moore, D.L.

    1995-06-01

    Increased water clarity due in large part to the invasion and spread of Dreissena polymorpha Pall., has allowed reestablishment of nearly continuous beds of submersed macrophytes in Put-in-Bay, Ohio. These beds now serve as sites for settlement by Dreissena veligers. Four transects extending from a maximum depth of 4.0 m to a minimum depth of 0.5 m were established in 1994, to document the time of recruitment, density of postveliger settlement, preferred macrophyte as a substrate, and effects of water depth and location within transects on recruitment. Settlement densities were determined for 100 g wet weight samples of macrophytes harvested along transects by snorkel and scuba. Peak settlement occurred 23 August, 11 days after the second planktonic veliger peak, but continued until early October. Maximum densities were greatest in 1.5-3.5 m water nearer the lakeward end of the transects and decreased in 1.0 m water or shoreward in dense submersed macrophyte beds. A maximum density of 15,150 Dreissena/100 g macrophyte occurred on the perennial Myriophyllum spicatum L., although mean settlement densities were greatest for the perennials M. spicatum, Ceratophyllum demersum L., and the annuals Vallisneria americana Michx. and Najas quadalupensis (Spreng.) Magnus. Macrophyte preference as a settling substrate is most probably a reflection of relative macrophyte abundance and position within dense beds rather than a particular plant architecture. Assessment of densities after autumnal vegetational growth is not yet complete.

  20. Revision of the stick insect genus Clitarchus Stål (Phasmatodea: Phasmatidae): new synonymies and two new species from northern New Zealand.

    PubMed

    Buckley, Thomas R; Myers, Shelley S; Bradler, Sven

    2014-01-01

    We describe two new species of Clitarchus Stål from Northland, New Zealand. Clitarchus rakauwhakanekeneke sp. nov. is described from the Poor Knights Islands and Clitarchus tepaki sp. nov. is described from the Te Paki / North Cape area and the Karikari Peninsula at the northernmost tip of New Zealand. Two new synonymies are proposed including Clitarchus multidentatus Brunner (syn. nov.) and Clitarchus tuberculatus Salmon (syn. nov.) as synonyms of Clitarchus hookeri (White). Clitarchus magnus Brunner, recorded from Thailand, is transferred to Ramulus Saussure and given the replacement name Ramulus changmaiense nom. nov. The holotype of C. multidentatus was recorded as being collected from New Caledonia; however we believe this is a labelling error and the specimen was collected from New Zealand. These taxonomic changes render Clitarchus endemic to New Zealand and consisting of three species; C. hookeri, C. rakauwhakanekeneke and C. tepaki. Keys to the adult males and females of Clitarchus species are given in addition to notes on host plants, ecology and geographic distributions. PMID:25543751

  1. The biological soil crusts of the San Nicolas Island: Enigmatic algae from a geographically isolated ecosystem

    USGS Publications Warehouse

    Flechtner, V.R.; Johansen, J.R.; Belnap, J.

    2008-01-01

    Composite soil samples from 7 sites on San Nicolas Island were evaluated quantitatively and qualitatively for the presence of cyanobacteria and eukaryotic microalgae. Combined data demonstrated a rich algal flora with 19 cyanobacterial and 19 eukaryotic microalgal genera being identified, for a total of 56 species. Nine new species were identified and described among the cyanobacteria and the eukaryotic microalgae that were isolated: Leibleinia edaphica, Aphanothece maritima, Chroococcidiopsis edaphica, Cyanosarcina atroveneta, Hassallia californica, Hassallia pseudoramosissima, Microchaete terrestre, Palmellopsis californiens, and Pseudotetracystis compactis. Distinct distributional patterns of algal taxa existed among sites on the island and among soil algal floras of western North America. Some algal taxa appeared to be widely distributed across many desert regions, including Microcoleus vaginatus, Nostoc punctiforme, Nostoc paludosum, and Tolypothrix distorta, Chlorella vulgaris, Diplosphaera cf. chodatii, Myrmecia astigmatica, Myrmecia biatorellae, Hantzschia amphioxys, and Luticola mutica. Some taxa share a distinctly southern distribution with soil algae from southern Arizona, southern California, and Baja California (e.g., Scenedesmus deserticola and Eustigmatos magnus). The data presented herein support the view that the cyanobacterial and microalgal floras of soil crusts possess significant biodiversity, much of it previously undescribed.

  2. Ivane S. Beritashvili (1884-1974): from spinal cord reflexes to image-driven behavior.

    PubMed

    Tsagareli, M G; Doty, R W

    2009-10-20

    Ivane Beritashvili ("Beritoff" in Russian, and often in Western languages) was a major figure in 20th-century neuroscience. Mastering the string galvanometer, he founded the electrophysiology of spinal cord reflexes, showing that inhibition is a distinctly different process from excitation, contrary to the concepts of his famous mentor, Wedensky. Work on postural reflexes with Magnus was cut short by World War I, but he later demonstrated that navigation in two-dimensional space without vision is a function solely of the vestibular system rather than of muscle proprioception. Persevering in his experiments despite postwar turmoil he founded an enduring Physiology Institute in Tbilisi, where he pursued an ingenious and extensive investigation of comparative memory in vertebrates. This revealed the unique nature of mammalian memory processes, which he forthrightly called "image driven," and distinguished them unequivocally from those underlying conditional reflexes. For some 30 years the Stalinist terror confined his publications to the Russian language. Work with his colleague, Chichinadze, discovering that memory confined to one cerebral hemisphere could be accessed by the other via a specific forebrain commissure, did reach the West, and ultimately led to recognition of the fascinating "split brain" condition. In the 1950s he was removed from his professorial position for 5 years as being "anti-Pavlovian." Restored to favor, he was honorary president of the "Moscow Colloquium" that saw the foundation of the International Brain Research Organization. PMID:19589370

  3. Afferent projections to the Bötzinger complex from the upper cervical cord and other respiratory related structures in the brainstem in cats: retrograde WGA-HRP tracing.

    PubMed

    Gang, S; Sato, Y; Kohama, I; Aoki, M

    1995-12-01

    Following injection of WGA-HRP (30-60 nl, 5%) into the Bötzinger complex (Böt.c), a group of expiratory neurons in the vicinity of the retrofacial nucleus, a number of labeled neurons were observed, predominantly ipsilaterally, in the intermediate zone of the upper cervical cord at the C1 and C2 segments, the retrotrapezoid nucleus (RTN) in the ventrolateral medulla and the parabrachial-Kölliker-Fuse nuclear complex in the rostral pons. In addition, clusters of labeled cells were also observed in and around the solitary tract nucleus, nuclei ambiguus and retroambiguus, and nucleus raphe magnus. Control injections into the magnocellular tegmental field adjacent to the Böt.c resulted in a diffuse distribution of labeled neurons in the reticular formation. These results demonstrate that the Böt.c receives convergent monosynaptic axonal projections from the upper cervical spinal cord, the pontine pneumotaxic area, the RTN and several other respiratory related structures in the medulla. PMID:8786271

  4. A preliminary survey of the epidemiology of bluetongue in Kenya

    PubMed Central

    Walker, A. R.; Davies, F. G.

    1971-01-01

    A survey of the species composition and distribution of the Culicoides midge populations at a range of sites where bluetongue is enzootic isolated a group of dominant species: C. cornutus, C. grahamii, C. magnus, C. milnei, C. pallidipennis and C. 23. † Monthly light-trap sampling of Culicoides showed that the population densities of the dominant species greatly increased after the rain seasons and that these species concentrated around flocks of sheep and cattle. The larval habitats of C. cornutus and C. pallidipennis were found associated with stock pens. Precipitin tests on blood-fed Culicoides showed that most of the dominant species regularly feed on sheep and cattle. Bluetongue virus was isolated from C. milnei, C. pallidipennis and C. 23. Serological surveys of wild and domestic bovids from the enzootic area showed a high proportion with antibody to bluetongue virus. The colonization of C. cornutus, a potential vector, is described briefly. A causal relationship between peak rainfall in April—May, peak numbers of Culicoides in May—June and peak bluetongue incidence in June—July is postulated. The vector status of the above species and C. austeni was evaluated. PMID:4337112

  5. Gateable Skyrmion Transport via Field-induced Potential Barrier Modulation

    PubMed Central

    Fook, Hiu Tung; Gan, Wei Liang; Lew, Wen Siang

    2016-01-01

    We report on the influence of pinning potentials on current-driven skyrmion dynamics and demonstrate that skyrmions can be gated via either magnetic or electric fields. When encountering pinning potentials, skyrmions are well known to simply skirt around them. However, we show that skyrmions can be depinned much more easily when their driving force is oriented against the pinning site rather that the intuitive option of being oriented away. This observation can be exploited together with the normally undesirable Magnus force for the creation of a skyrmion diode. The phenomenon is explained by the increased skyrmion compression resulting from the spin transfer torque opposing the repulsive potential. The smaller skyrmion size then experiences a reduced pinning potential. For practical low-power device applications, we show that the same skyrmion compression can be recreated by applying either a magnetic or electric field. Our analysis provides an insight on the skyrmion dynamics and manipulation that is critical for the realization of skyrmion-based transistors and low-power memory. PMID:26883575

  6. STS-112 crew practices emergency egress training during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- During emergency egress training from the launch pad, the STS-112 crew get instructions on using the slidewire basket. From left, Mission Specialist Piers Sellers (back to camera), Pilot Pamela Melroy, Mission Specialists Sandra Magnus and Fyodor Yurchikhin (with the Russian Space Agency), watch as Commander Jeffrey Ashby (below right) grabs the release lever. Not seen is Mission Specialist David Wolf. The training is part of Terminal Countdown Demonstration Test activities, which include a simulated launch countdown. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  7. Flight and Stability of a Laser Inertial Fusion Energy Target in the Drift Region between Injection and the Reaction Chamber with Computational Fluid Dynamics

    SciTech Connect

    Mitori, T.

    2013-12-01

    A Laser Inertial Fusion Energy (LIFE) target’s flight through a low Reynolds number and high Mach number regime was analyzed with computational fluid dynamics software. This regime consisted of xenon gas at 1,050 K and approximately 6,670 Pa. Simulations with similar flow conditions were performed with a sphere and compared with experimental data and published correlations for validation purposes. Transient considerations of the developing flow around the target were explored. Simulations of the target at different velocities were used to determine correlations for the drag coefficient and Nusselt number as functions of the Reynolds number. Simulations with different angles of attack were used to determine the aerodynamic coefficients of drag, lift, Magnus moment, and overturning moment as well as target stability. The drag force, lift force, and overturning moment changed minimally with spin. Above an angle of attack of 15°, the overturning moment would be destabilizing. At low angles of attack (less than 15°), the overturning moment would tend to decrease the target’s angle of attack, indicating the lack of a need for spin for stability at small angles. This stabilizing moment would cause the target to move in a mildly damped oscillation about the axis parallel to the free-stream velocity vector through the target’s center of gravity.

  8. Contribution of anterior cingulate cortex and descending pain inhibitory system to analgesic effect of lemon odor in mice

    PubMed Central

    2014-01-01

    Background Affections are thought to regulate pain perception through the descending pain inhibitory system in the central nervous system. In this study, we examined in mice the affective change by inhalation of the lemon oil, which is well used for aromatherapy, and the effect of lemon odor on pain sensation. We also examined the anterior cingulate cortex (ACC) and descending pain inhibitory system to such regulation of pain. Results In the elevated plus maze, the time spent in the open arms was increased by inhalation of lemon oil. The pain behavior induced by injection of formalin into the hind paw was decreased. By inhalation of lemon oil, the number of c-Fos expression by formalin injection was significantly increased in the ACC, periaqueductal grey (PAG), nucleu raphe magnus (NRM) and locus ceruleus, and decreased in the spinal dorsal horn (SDH). The destruction of the ACC with ibotenic acid led to prevent the decrease of formalin-evoked nocifensive behavior in mice exposed to lemon oil. In these mice, the change of formalin-induced c-Fos expression in the ACC, lateral PAG, NRM and SDH by lemon odor was also prevented. Antagonize of dopamine D1 receptor in the ACC prevented to the analgesic effect of lemon oil. Conclusions These results suggest that the analgesic effect of lemon oil is induced by dopamine-related activation of ACC and the descending pain inhibitory system. PMID:24555533

  9. Aerodynamics of sports balls

    NASA Astrophysics Data System (ADS)

    Mehta, R. D.

    Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.

  10. Analysis of muscle forces acting on fragments in pelvic fractures.

    PubMed

    Elabjer, Esmat; Nikolić, Vasilije; Matejcić, Aljosa; Stancić, Marin; Kuzmanović Elabjer, Biljana

    2009-12-01

    CT was used in 50 adult pelvic fractures to determine the size and the position of relevant muscles with regard to bony elements in order to calculate muscle forces acting upon certain pelvic portions. Muscle length was measured to calculate muscle volume and physiological muscle cross-section. Among others, the size and direction of muscle forces were calculated for iliac, pubic and ischiadic fractures. The strongest muscle acting in iliac fractures is m. gluteus medius. The strongest upward pulling of iliac bone fragments is exerted by the erector muscles, while the major anterior, medial and downward pulling is performed by the iliopsoas muscle. In pubic bone fractures, eight muscles push bone fragments downward, the strongest among them being m. adductor magnus. Two muscles pull them upwards: m. rectus abdominis and m. obliquus externus. Nine muscles are responsible for downward displacement of bone fragments in ischiadic fractures, but the strongest is m. semitendinosus. Calculation of moments of muscle forces acting upon bone fragments using CT of pelvic fractures gives additional data for planning of optimal operative treatment that can guarantee stable fixation in individual patients. PMID:20102053

  11. Electromyographic analysis of thigh muscles during track cycling on a velodrome.

    PubMed

    Watanabe, Kohei; Sato, Takayuki; Mukaimoto, Takahiro; Takashima, Wataru; Yamagishi, Michio; Nishiyama, Tetsunari

    2016-08-01

    We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles. PMID:26571039

  12. STS-112 crew takes a group photo at the 215-foot level

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. - The STS-112 crew gathers for a group photo on the 215-foot level of the Fixed Service Structure. From left are Mission Specialists Fyodor Yurchikhin, Piers Sellers and David Wolf; Pilot Pamela Melroy; Commander Jeffrey Ashby; and Mission Specialist Sandra Magnus. Behind them at left is seen one of the white solid rocket boosters and the orange external tank on Space Shuttle Atlantis. Mission STS-112 is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. The 11-day mission is expected to conclude with a landing at KSC Oct. 13.

  13. STS-112 crew arrives at KSC's SLF for launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-112 crew members share a few words after their arrival at the KSC Shuttle Landing Facility to begin launch preparations. In the center are Commander Jeffrey Ashby (left) and Mission Specialist David Wolf (right). With their backs to the camera are Mission Specialists Piers Sellers (far left) and Sandra Magnus (far right). Not shown are Pilot Pamela Melroy and Mission Specialist Fyodor Yurchikhin, who is with the Russian Space Agency. STS-112, aboard Space Shuttle Atlantis, is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts. The 11-day mission includes three spacewalks. Launch is scheduled for Oct. 2 between 2 and 6 p.m.

  14. The Medieval Origins of the Concept of Hypertension

    PubMed Central

    Heydari, Mojtaba; Dalfardi, Behnam; Golzari, Samad E. J.; Habibi, Hamzeh; Zarshenas, Mohammad Mehdi

    2014-01-01

    Despite the well-known history of hypertension research in the modern era, like many other cardiovascular concepts, main points in the medieval concept of this disease and its early management methods remain obscure. This article attempts to make a brief review on the medieval origin of the concept of this disease from the Hidayat of Al-Akhawayni (?-983 AD). This article has reviewed the chapter of “Fi al-Imtela” (About the Fullness) from the Hidβyat al-Muta’allimin fi al-Tibb (The Students' Handbook of Medicine) of Al-Akhawayni. The definition, symptoms and treatments presented for the Imtela are compared with the current knowledge on hypertension. Akhawayni believed that Imtela could result from the excessive amount of blood within the blood vessels. It can manifest with symptoms including the presence of a pulsus magnus, sleepiness, weakness, dyspnea, facial blushing, engorgement of the vessels, thick urine, vascular rupture, and hemorrhagic stroke. He also suggested some ways to manage al-Imtela'. These include recommendations of changes in lifestyle (staying away from anger and sexual intercourse) and dietary program for patients (avoiding the consumption of wine, meat, and pastries, reducing the volume of food in a meal, maintaining a low-energy diet and the dietary usage of spinach and vinegar). Al-Akhawayni's description of “Imtela,” despite of its numerous differences with current knowledge of hypertension, can be considered as medieval origin of the concept of hypertension. PMID:25538828

  15. STS-112 Crew Portrait

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These 5 astronauts and cosmonaut, all members of the STS-112 mission, pose for a crew portrait. Pictured from left to right are: Astronauts Sandra H. Magnus, mission specialist; David A. Wolf, mission specialist; Pamela A. Melroy, pilot; Jeffrey S. Ashby, commander; Piers J. Sellers, mission specialist; and cosmonaut Fyodor Yurchikhin, mission specialist representing Rosaviakosmos. STS-112 launched aboard the Space Shuttle Atlantis October 7, 2002 for an 11-day mission completing three sessions of Extra Vehicular Activity(EVA). Its primary mission was to install the Starboard (S1) Integrated Truss Structure and Equipment Translation Aid (CETA) Cart to the ISS. The S1 truss provides structural support for the orbiting research facility's radiator panels, which use ammonia to cool the Station's complex power system. The S1 truss, attached to the S0 (S Zero) truss installed by the previous STS-110 mission, flows 637 pounds of anhydrous ammonia through three heat rejection radiators. The truss is 45-feet long, 15-feet wide, 10-feet tall, and weighs approximately 32,000 pounds. The CETA is the first of two human-powered carts that will ride along the railway on the ISS providing a mobile work platform for future extravehicular activities by astronauts.

  16. Analgesic Neural Circuits Are Activated by Electroacupuncture at Two Sets of Acupoints

    PubMed Central

    Hu, Man-Li; Qiu, Zheng-Ying

    2016-01-01

    To investigate analgesic neural circuits activated by electroacupuncture (EA) at different sets of acupoints in the brain, goats were stimulated by EA at set of Baihui-Santai acupoints or set of Housanli acupoints for 30 min. The pain threshold was measured using the potassium iontophoresis method. The levels of c-Fos were determined with Streptavidin-Biotin Complex immunohistochemistry. The results showed pain threshold induced by EA at set of Baihui-Santai acupoints was 44.74% ± 4.56% higher than that by EA at set of Housanli acupoints (32.64% ± 5.04%). Compared with blank control, EA at two sets of acupoints increased c-Fos expression in the medial septal nucleus (MSN), the arcuate nucleus (ARC), the nucleus amygdala basalis (AB), the lateral habenula nucleus (HL), the ventrolateral periaqueductal grey (vlPAG), the locus coeruleus (LC), the nucleus raphe magnus (NRM), the pituitary gland, and spinal cord dorsal horn (SDH). Compared with EA at set of Housanli points, EA at set of Baihui-Santai points induced increased c-Fos expression in AB but decrease in MSN, the paraventricular nucleus of the hypothalamus, HL, and SDH. It suggests that ARC-PAG-NRM/LC-SDH and the hypothalamus-pituitary may be the common activated neural pathways taking part in EA-induced analgesia at the two sets of acupoints. PMID:27429635

  17. Atmospheric Flight Mechanics Conference, Williamsburg, VA, August 18-20, 1986, Technical Papers

    SciTech Connect

    Not Available

    1986-01-01

    The present conference considers a robust adaptive flightpath reconstruction technique, the application of parameter estimation to highly unstable aircraft, dynamical path optimization of aerospace vehicles, the use of flight simulation to develop terminal instrument procedures for transport category aircraft, the flight dynamics of aeroelastic vehicles, optimal missile range with respect to thrust and altitude profiles, the attenuation of Magnus effect on a missile with N-vanes, the effects of heave damping on helicopter handling qualitities, and an optimal descending hypersonic turn-to-heading. Also discussed are an unsteady low speed aerodynamic model for complete aircraft configurations, a dynamic model for the real time estimation of aerodynamic characteristics, the aerodynamics of delta wings with leading edge blowing, an analysis of airline flight records for winds and performance with reference to the Delta 191 accident, the use of hinged strakes for lateral control at high angles-of-attack, vortex-induced effects on aircraft dynamics, the spherical mapping and analysis of aircraft angles for maneuvering flight, and a concept of automated aircraft guidance for air-to-air missiles.

  18. Berry curvature and dynamics of a magnetic bubble

    NASA Astrophysics Data System (ADS)

    Koshibae, Wataru; Nagaosa, Naoto

    2016-04-01

    Magnetic bubbles have been the subject of intensive studies aiming to investigate their applications to memory devices. A bubble can be regarded as the closed domain wall and is characterized by the winding number of the in-plane components or the skyrmion number N sk , which are related to the number of Bloch lines (BLs). For the magnetic bubbles without BLs, the Thiele equation assuming no internal distortion describes the center-of-mass motion of the bubbles very well. For the magnetic bubbles with BLs, on the other hand, their dynamics is affected seriously by that of BLs along the domain wall. Here we show theoretically, that the distribution of the Berry curvature b z , i.e., the solid angle formed by the magnetization vectors, in the bubble plays the key role in the dynamics of a bubble with {N}{sk}=0 in a dipolar magnet. In this case, the integral of b z over the space is zero, while the nonuniform distribution of b z and associated Magnus force induce several nontrivial coupled dynamics of the internal deformation and center-of-mass motion as explicitly demonstrated by numerical simulations of Landau–Lifshitz-Gilbert equation. These findings give an alternative view and will pave a new route to design the bubble dynamics.

  19. Universal current-velocity relation of skyrmion motion in chiral magnets.

    PubMed

    Iwasaki, Junichi; Mochizuki, Masahito; Nagaosa, Naoto

    2013-01-01

    Current-driven motion of the magnetic domain wall in ferromagnets is attracting intense attention because of potential applications such as racetrack memory. There, the critical current density to drive the motion is ~10(9)-10(12) A m(-2). The skyrmions recently discovered in chiral magnets have much smaller critical current density of ~10(5)-10(6) A m(-2), but the microscopic mechanism is not yet explored. Here we present a numerical simulation of Landau-Lifshitz-Gilbert equation, which reveals a remarkably robust and universal current-velocity relation of the skyrmion motion driven by the spin-transfer-torque unaffected by either impurities or nonadiabatic effect in sharp contrast to the case of domain wall or spin helix. Simulation results are analysed using a theory based on Thiele's equation, and it is concluded that this behaviour is due to the Magnus force and flexible shape-deformation of individual skyrmions and skyrmion crystal, which enable them to avoid pinning centres. PMID:23403564

  20. Brainstem metabotropic glutamate receptors reduce food intake and activate dorsal pontine and medullar structures after peripheral bacterial lipopolysaccharide administration.

    PubMed

    Chaskiel, Léa; Paul, Flora; Gerstberger, Rüdiger; Hübschle, Thomas; Konsman, Jan Pieter

    2016-08-01

    During infection-induced inflammation food intake is reduced. Vagal and brainstem pathways are important both in feeding regulation and immune-to-brain communication. Glutamate is released by vagal afferent terminals in the nucleus of the solitary tract and by its neurons projecting to the parabrachial nuclei. We therefore studied the role of brainstem glutamate receptors in spontaneous food intake of healthy animals and during sickness-associated hypophagia after peripheral administration of bacterial lipopolysaccharides or interleukin-1beta. Brainstem group I and II metabotropic, but not ionotropic, glutamate receptor antagonism increased food intake both in saline- and lipopolysaccharide-treated rats. In these animals, expression of the cellular activation marker c-Fos in the lateral parabrachial nuclei and lipopolysaccharide-induced activation of the nucleus of the solitary tract rostral to the area postrema were suppressed. Group I metabotropic glutamate receptors did not colocalize with c-Fos or neurons regulating gastric function in these structures. Group I metabotropic glutamate receptors were, however, found on raphé magnus neurons that were part of the brainstem circuit innervating the stomach and on trigeminal and hypoglossal motor neurons. In conclusion, our findings show that brainstem metabotropic glutamate receptors reduce food intake and activate the lateral parabrachial nuclei as well as the rostral nucleus of the solitary tract after peripheral bacterial lipopolysaccharide administration. They also provide insight into potential group I metabotropic glutamate receptor-dependent brainstem circuits mediating these effects. PMID:27016016

  1. Effective Hamiltonians for Rapidly Driven Many-Body Lattice Systems: Induced Exchange Interactions and Density-Dependent Hoppings

    NASA Astrophysics Data System (ADS)

    Itin, A. P.; Katsnelson, M. I.

    2015-08-01

    We consider 1D lattices described by Hubbard or Bose-Hubbard models, in the presence of periodic high-frequency perturbations, such as uniform ac force or modulation of hopping coefficients. Effective Hamiltonians for interacting particles are derived using an averaging method resembling classical canonical perturbation theory. As is known, a high-frequency force may renormalize hopping coefficients, causing interesting phenomena such as coherent destruction of tunneling and creation of artificial gauge fields. We find explicitly additional corrections to the effective Hamiltonians due to interactions, corresponding to nontrivial processes such as single-particle density-dependent tunneling, correlated pair hoppings, nearest neighbor interactions, etc. Some of these processes arise also in multiband lattice models, and are capable of giving rise to a rich variety of quantum phases. The apparent contradiction with other methods, e.g., Floquet-Magnus expansion, is explained. The results may be useful for designing effective Hamiltonian models in experiments with ultracold atoms, as well as in the field of ultrafast nonequilibrium magnetism. An example of manipulating exchange interaction in a Mott-Hubbard insulator is considered, where our corrections play an essential role.

  2. Elastohydrodynamics of a sliding, spinning and sedimenting cylinder near a soft wall

    NASA Astrophysics Data System (ADS)

    Salez, Thomas; Mahadevan, L.

    2015-09-01

    We consider the motion of a fluid-immersed negatively buoyant particle in the vicinity of a thin compressible elastic wall, a situation that arises in a variety of technological and natural settings. We use scaling arguments to establish different regimes of sliding, and complement these estimates using thin-film lubrication dynamics to determine an asymptotic theory for the sedimentation, sliding, and spinning motions of a cylinder. The resulting theory takes the form of three coupled nonlinear singular-differential equations. Numerical integration of the resulting equations confirms our scaling relations and further yields a range of unexpected behaviours. Despite the low-Reynolds feature of the flow, we demonstrate that the particle can spontaneously oscillate when sliding, can generate lift via a Magnus-like effect, can undergo a spin-induced reversal effect, and also shows an unusual sedimentation singularity. Our description also allows us to address a sedimentation-sliding transition that can lead to the particle coasting over very long distances, similar to certain geophysical phenomena. Finally, we show that a small modification of our theory allows to generalize the results to account for additional effects such as wall poroelasticity.

  3. Revealing the diversity of Cloeodes Traver, 1938 (Ephemeroptera: Baetidae) in the Neotropics: description of eleven new species from Brazilian mountain ranges.

    PubMed

    Salles, F F; Massariol, F C; Angeli, K B; Lima, M M; Gattolliat, J-L; Sartori, M

    2015-01-01

    In the present work, based on material from distinct mountain ranges in Brazil, 11 new species of Cloeodes with hind wings or hind wing pads are described, illustrated and discussed. Among the new species, in C. aiuruoca, C. amantykyra, C. atlanticus, C. boldrinii and C. ioachimi, the apex of the fore femora in the nymphs is extremely projected (a characteristic previously found only in two species of the genus). Cloeodes guara and C. tracheatus share the presence of unusual large and dark gills. Cloeodes melanotarsus is readily distinguished by conspicuous blackish tarsi, C. lucifer by the bright yellow coloration of tergum I, and C. xyrognathos by blade-like incisors. Cloeodes magnus, besides being the largest species of the genus, with a body size reaching 12 mm, possess short maxillary palp. Comments on the presence of C. irvingi and C. opacus in Brazil are also provided. An interactive online key is provided for the nymphs of all the species of Cloeodes in which hind wing pads are present. PMID:26624088

  4. The Flight of a Baseball

    NASA Astrophysics Data System (ADS)

    Nathan, Alan

    2010-03-01

    The trajectory of a baseball moving through the air is very different from the one we teach in our introductory classes in which the only force is that due to gravity. In reality, the aerodynamic drag force (which retards the motion) and the Magnus force on a spinning baseball (which causes the ball to curve) play very important roles that are crucial to many of the subtleties of the game. These forces are governed by three phenomenological quantities: the coefficients of drag, lift, and moment, the latter determining the spin decay time constant. In past years, these quantities were studied mainly in wind tunnel experiments, whereby the forces on the baseball are measured directly. More recently, new tools have been developed that focus on measuring accurate baseball trajectories, from which the forces can be inferred. These tools include high-speed motion analysis, video tracking (the so-called PITCHf/x and HITf/x systems), and Doppler radar tracking via the TrackMan system. In this talk, I will discuss how these new tools work, what they are teaching us about baseball aerodynamics, and how they have the potential to revolutionize the analysis of the game itself.

  5. Why bigger may in fact be better... in the context of table tennis

    NASA Astrophysics Data System (ADS)

    Truscott, Tadd; Pan, Zhao; Belden, Jesse

    2014-11-01

    We submit that table tennis is too fast. Because of the high ball velocities relative to the small table size, players are required to act extremely quickly, often exceeding the limits of human reaction time. Additionally, the Magnus effect resulting from large rotation rates introduces dramatically curved paths and causes rapid direction changes after striking the table or paddle, which effectively reduces reaction time further. Moreover, watching a professional game is often uninteresting and even tiring because the ball is moving too quickly to follow with the naked eye and the action of the players is too subtle to resolve from a distance. These facts isolate table tennis from our quantitatively defined ``fun game club,'' and make it less widely appealing than sports like baseball and soccer. Over the past 100 years, the rules of table tennis have changed several times in an effort to make the game more attractive to players and spectators alike, but the game continues to lose popularity. Here, we experimentally quantify the historic landmark equipment changes of table tennis from a fluid dynamics perspective. Based on theory and observation, we suggest a larger diameter ball for table tennis to make the game more appealing to both spectators and amateur players.

  6. Aerodynamics of sports balls

    NASA Technical Reports Server (NTRS)

    Mehta, R. D.

    1985-01-01

    Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.

  7. The effect of spin on the flight of a baseball

    NASA Astrophysics Data System (ADS)

    Nathan, Alan M.

    2008-02-01

    Measurements are presented of the Magnus force on a spinning baseball. The experiment utilizes a pitching machine to project the baseball horizontally, a high-speed motion analysis system to determine the initial velocity and angular velocity and to track the trajectory over 5m of flight, and a ruler to measure the total distance traversed. Speeds in the range v =50-110mph and spin rates ω (topspin or backspin) in the range 1500-4500rpm were utilized, corresponding to Reynolds numbers of Re =(1.1-2.4)×105 and spin factors S ≡Rω/v in the range 0.090-0.595. Least-squares fits were used to extract the initial parameters of the trajectory and to determine the lift coefficients. Comparison is made with previous measurements and parametrizations, and implications for the effect of spin on the flight of a baseball are discussed. The lift coefficient CL is found not to depend strongly on v at fixed values of S.

  8. STS-112 Flight Day 10 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On Flight Day 10 of the STS-112 mission, its crew (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Mission Specialist; Piers Sellers, Mission Specialist; Sandra Magnus, Mission Specialist; Fyodor Yurchikhin, Mission Specialist) on the Atlantis and the Expedition 5 crew on the International Space Station (ISS) (Valery Korzun, Commander; Peggy Whitson, Flight Engineer; Sergei Treschev, Flight Engineer) are shown exchanging farewells in the ISS's Destiny Laboratory Module following the completion of a week-long period of docked operations. The Expedition 5 crew is nearing the end of five and a half continuous months aboard the space station. Following the closing of the hatches, the Atlantis Orbiter undocks from the station, and Melroy pilots the shuttle slowly away from the ISS, and engages in a radial fly-around of the station. During the fly-around cameras aboard Atlantis shows ISS from a number of angles. ISS cameras also show Atlantis. There are several shots of each craft with a variety of background settings including the Earth, its limb, and open space. The video concludes with a live interview of Ashby, Melroy and Yurchikhin, still aboard Atlantis, conducted by a reporter on the ground. Questions range from feelings on the conclusion of the mission to the experience of being in space. The primary goal of the mission was the installation of the Integrated Truss Structure S1 on the ISS.

  9. STS-112 Flight Day 3 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    During the third flight day of STS-112 (Commander Jeff Ashby, Pilot Pam Melroy and Mission Specialists Sandy Magnus, Piers Sellers, David Wolf and Fyodor Yurchikhin), the Space Shuttle Atlantis begins its final approach to the International Space Station (ISS) with which it will dock. The Chinese mainland is seen, at night, at a height of 242 statute miles. In one section of video from a camera onboard the ISS, Atlantis can be seen to be almost directly below the station, at a distance of several hundred feet. The orbiter's docking system is shown, as it is slowly guided by Ashby towards the forward docking port on the ISS's Destiny Laboratory Module and its forward docking port. Above the docking port, the S0 truss structure can be seen, to which the S1 truss structure in Atlantis' payload bay will be attached during this mission. Also seen are the Unity airlock and other modules. Following the completion of docking, in which an excellent shot of the docking system in hard dock is visible, the hatches between the two crafts are opened and the members of Atlantis are greeted by the very excited members of Expedition 5, who have been aboard the ISS for several months.

  10. STS-112 Flight Day 6 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On the sixth flight day of STS-112 (Atlantis crewmembers include Dave Wolf, Mission Specialists; Sandy Magnus, Mission Specialists; Pam Melroy, Pilot; Jeff Ashby, Commander; Piers Sellers, Mission Specialists; Fyodor Yurchikhin, Mission Specialists), Wolf and Sellers are seen preparing for an EVA (extravehicular activity) during which they will service the ISS (International Space Station) to which Atlantis is docked. This will be the 45th EVA in support of ISS assembly and maintenance and the 20th conducted from the ISS. While the astronauts prepare, video footage is shown of the Sahara desert, over which the ISS is passing in a track that will take it over North Africa and the Mediterranean Sea. During the EVA, the External Television Camera Group will be brought out of the station and attached to the station. As the astronauts work, their helmet mounted cameras provide excellent footage of the ISS with the Shuttle docked at the Destiny Laboratory Module. Multiple shots of the station show several modules including Destiny, Quest, Unity and Zarya, as well as Canadarm 2 and Atlantis. The video closes with a wide angle shot of the ISS.

  11. Antiferromagnetic Skyrmion: Stability, Creation and Manipulation

    PubMed Central

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-01-01

    Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topo-logical number Q = ± 1, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials. PMID:27099125

  12. High-fidelity two-qubit gates via dynamical decoupling of local 1 /f noise at the optimal point

    NASA Astrophysics Data System (ADS)

    D'Arrigo, A.; Falci, G.; Paladino, E.

    2016-08-01

    We investigate the possibility of achieving high-fidelity universal two-qubit gates by supplementing optimal tuning of individual qubits with dynamical decoupling (DD) of local 1 /f noise. We consider simultaneous local pulse sequences applied during the gate operation and compare the efficiencies of periodic, Carr-Purcell, and Uhrig DD with hard π pulses along two directions (πz /y pulses). We present analytical perturbative results (Magnus expansion) in the quasistatic noise approximation combined with numerical simulations for realistic 1 /f noise spectra. The gate efficiency is studied as a function of the gate duration, of the number n of pulses, and of the high-frequency roll-off. We find that the gate error is nonmonotonic in n , decreasing as n-α in the asymptotic limit, α ≥2 , depending on the DD sequence. In this limit πz-Urhig is the most efficient scheme for quasistatic 1 /f noise, but it is highly sensitive to the soft UV cutoff. For small number of pulses, πz control yields anti-Zeno behavior, whereas πy pulses minimize the error for a finite n . For the current noise figures in superconducting qubits, two-qubit gate errors ˜10-6 , meeting the requirements for fault-tolerant quantum computation, can be achieved. The Carr-Purcell-Meiboom-Gill sequence is the most efficient procedure, stable for 1 /f noise with UV cutoff up to gigahertz.

  13. Gateable Skyrmion Transport via Field-induced Potential Barrier Modulation.

    PubMed

    Fook, Hiu Tung; Gan, Wei Liang; Lew, Wen Siang

    2016-01-01

    We report on the influence of pinning potentials on current-driven skyrmion dynamics and demonstrate that skyrmions can be gated via either magnetic or electric fields. When encountering pinning potentials, skyrmions are well known to simply skirt around them. However, we show that skyrmions can be depinned much more easily when their driving force is oriented against the pinning site rather that the intuitive option of being oriented away. This observation can be exploited together with the normally undesirable Magnus force for the creation of a skyrmion diode. The phenomenon is explained by the increased skyrmion compression resulting from the spin transfer torque opposing the repulsive potential. The smaller skyrmion size then experiences a reduced pinning potential. For practical low-power device applications, we show that the same skyrmion compression can be recreated by applying either a magnetic or electric field. Our analysis provides an insight on the skyrmion dynamics and manipulation that is critical for the realization of skyrmion-based transistors and low-power memory. PMID:26883575

  14. Geometric morphometrics of the shoulder girdle in extant turtles (Chelonii)

    PubMed Central

    Depecker, Marion; Berge, Christine; Penin, Xavier; Renous, Sabine

    2006-01-01

    The aim of this study was to identify shape patterns of the shoulder girdle in relation to different functional and environmental behaviours in turtles. The Procrustes method was used to compare the shoulder girdles (scapula and coracoid) of 88 adult extant turtles. The results indicate that four shape patterns can be distinguished. The shoulder girdles of (1) terrestrial (Testudinidae), (2) highly aquatic freshwater (Trionychidae, Carettochelyidae) and (3) marine turtles (Cheloniidae, Dermochelyidae) correspond to three specialized morphological patterns, whereas the shoulder girdle of (4) semi-aquatic freshwater turtles (Bataguridae, Chelidae, Chelydridae, Emydidae, Kinosternidae, Pelomedusidae, Platysternidae, Podocnemididae) is more generalized. In terrestrial turtles, the long scapular prong and the short coracoid are associated with a domed shell and a mode of locomotion in which walking is predominant. By contrast, highly aquatic freshwater turtles share traits with marine turtles. In both, the short scapular prong and the long coracoid are associated with a flat shell, and swimming locomotion. The enlarged attachment sites of the biceps, coracobrachialis magnus, and supracoracoideus also give these strong swimmers a mechanical advantage during adduction and retraction of the arm. Increasing size leads to allometrical shape changes that emphasize mechanical efficiency both in terrestrial and in aquatic turtles. PMID:16420377

  15. A taxonomic revision of the genus Oxyopomyrmex André, 1881 (Hymenoptera: Formicidae).

    PubMed

    Salata, Sebastian; Borowiec, Lech

    2015-01-01

    Oxyopomyrmex André, 1881 is a small genus of myrmicine ants found in arid grasslands of the Mediterranean region. Here we provide a new taxonomic revision of the genus. Twelve species are recognized, including five new to science: O. laevibus sp. nov. (Greece: Crete), O. magnus sp. nov. (Spain), O. negevensis sp. nov. (Israel) O. polybotesi sp. nov. (Greece: Nisyros, W Turkey) and O. pygmalioni sp. nov. (Cyprus). Oxyopomyrmex santschii var. nigripes Santschi, 1907 and O. santschii var. nitidior Santschi, 1910 are raised to species level. The following new synonymies are proposed: O. krueperi Forel, 1911 = O. lagoi Menozzi, 1936 syn. nov.; O. nigripes Santschi, 1907 = O. sabulonis var. rugocciput Santschi, 1923 syn. nov. = O. emeryi var. brunnescens Santschi, 1929 syn. nov.; O. nitidior Santschi, 1910 = O. emeryi var. laticeps Santschi, 1915 syn. nov. = O. emeryi st. sabulonis Santschi, 1915 syn. nov.; O. saulcyi Emery, 1889 = O. santschii Forel, 1904 syn. nov. = O. santschii var. siciliana Karavaiev, 1912 syn. nov. = O. gaetulus Santschi, 1929 syn. nov. = O. saulcyi var. latinodis Santschi, 1939 syn. nov. A neotype for O. oculatus André, 1881 is designated. An identification key based on the gyne, male and worker caste is provided. PMID:26624163

  16. A New Technique for Studying the Pinning Force on a Single Vortex in a Thin-Film Superconductor

    NASA Astrophysics Data System (ADS)

    Cunningham, Charles E.; de Young, Tyce; Cochran, Matthew; Rinehart, Adam; Peterson, Sarah; Andrews, Timothy

    1998-03-01

    We have developed a new SQUID-based technique for studying the pinning of a single vortex in a superconducting thin film patterned into a cross shape. Ends of each strip are connected via superconducting wires to the input coils of two SQUIDs, forming superconducting inductive loops. The vortex is trapped by heating the intersection of the cross above its critical temperature with a laser pulse.(G.S. Park, C.E. Cunningham, B. Cabrera, and M.E. Huber, J. Appl. Phys. 73 (1993) 2419.) The vortex is detected and its position measured by a shift in the quantization currents in the loops coupled to the SQUIDs. This technique provides a combination of good temporal and spatial resolution of the vortex position. By sending currents through both strips, we can exert on the vortex a Magnus force in any direction, and we can detect its motion in the superconductor with the SQUIDs. We are using this technique to study flux motion between pinning sites and to measure the temperature-dependence of the pinning force in thin-film niobium.

  17. Anti-inflammatory and analgesic components from "hierba santa," a traditional medicine in Peru.

    PubMed

    Kawano, Marii; Otsuka, Mayumi; Umeyama, Kazuhiro; Yamazaki, Mikio; Shiota, Tetsuo; Satake, Motoyoshi; Okuyama, Emi

    2009-04-01

    "Hierba santa," a Peruvian herbal medicine, is used to alleviate many symptoms, including headache, hemorrhoids, fever, and rheumatism. Several Cestrum species are said to be the origin of hierba santa. Three lots of hierba santa: Cestrum auriculatum (herb 1 and herb 2) and C. hediundinum (herb 3), which were purchased from Peruvian markets at Cuzco (Andes area) and Equitos (Amazon area), respectively, were examined for their pharmacological activities and active components. Herbs 1-3 showed anti-inflammatory and analgesic activities in the in vivo writhing inhibition test in mouse and inhibited prostaglandin E(1)-, E(2)-, or ACh-induced contractions of guinea pig ileum in the Magnus method. Activity-based separation of each extract yielded cestrumines A and B, cestrusides A and B, a mixture of (+)- and (-)-pinoresinol glucosides, nicotiflorin, rutin, sinapoyl glucose, ursolic acid, beta-sitosteryl glucoside, and 2-sec-butyl-4,6-dihydroxyphenyl-beta-D: -glucopyranoside. Among them, cestrumine A and cestrusides A and B are new compounds. All three lots of hierba santa do not contain exactly the same active components. PMID:19067116

  18. Modifications of arterial baroreflexes: obligatory roles in cardiovascular regulation in stress and poststress recovery.

    PubMed

    Nosaka, S

    1996-08-01

    Despite the physiological importance of arterial baroreflexes as a powerful stabilizer of blood pressure, their functions themselves are not always stable and there are a variety of circumstances in which they are significantly modulated. During stressful conditions, including fight/flight, defense/attack, somatic nociception, visceral nociception, exercise, and mental stress, arterial baroreflexes are generally inhibited. The inhibition is purposeful for achieving dynamic readjustment of circulation needed for the animal's reaction to cope with these conditions. Central sites which are proposed to be involved in the inhibition include the motor cortex, amygdala, hypothalamus, dorsolateral part of the periaqueductal gray matter, parabrachial nucleus, cerebellar vermis, etc. On the other hand, arterial baroreflexes are occasionally facilitated, during sleep, following endurance exercise, etc. The facilitation favors restoration of energy exhausted during a stressful phase in which the animal reacts actively to changing environment. The central sites proven to elicit the facilitation are the medial prefrontal cortex, the preoptic/anterior hypothalamus, the ventrolateral part of the periaqueductal gray matter, and the nucleus raphe magnus. The inhibition and facilitation of arterial baroreflexes, which probably occur alternatively, are essential mechanisms supporting reactions to stressful conditions and poststress recovery, respectively. This review describes when, how, and why the arterial baroreflexes are so modulated. PMID:8988438

  19. Selection of optimal muscle set for 16-channel standing neuroprosthesis

    PubMed Central

    Gartman, Steven J.; Audu, Musa L.; Kirsch, Robert F.; Triolo, Ronald J.

    2009-01-01

    The Case Western Reserve University/Department of Veterans Affairs 8-channel lower-limb neuroprosthesis can restore standing to selected individuals with paraplegia by application of functional electrical stimulation. The second generation of this system will include 16 channels of stimulation and a closed-loop control scheme to provide automatic postural corrections. This study used a musculoskeletal model of the legs and trunk to determine which muscles to target with the new system in order to maximize the range of postures that can be statically maintained, which should increase the system’s ability to provide adequate support to maintain standing when the user’s posture moves away from a neutral stance, either by an external disturbance or a volitional change in posture by the user. The results show that the prime muscle targets should be the medial gastrocnemius, tibialis anterior, vastus lateralis, semimembranosus, gluteus maximus, gluteus medius, adductor magnus, and erector spinae. This set of 16 muscles supports 42 percent of the standing postures that are attainable by the nondisabled model. Coactivation of the lateral gastrocnemius and peroneus longus with the medial gastrocnemius and of the peroneus tertius with the tibialis anterior increased the percentage of feasible postures to 71 percent. PMID:16847793

  20. Gateable Skyrmion Transport via Field-induced Potential Barrier Modulation

    NASA Astrophysics Data System (ADS)

    Fook, Hiu Tung; Gan, Wei Liang; Lew, Wen Siang

    2016-02-01

    We report on the influence of pinning potentials on current-driven skyrmion dynamics and demonstrate that skyrmions can be gated via either magnetic or electric fields. When encountering pinning potentials, skyrmions are well known to simply skirt around them. However, we show that skyrmions can be depinned much more easily when their driving force is oriented against the pinning site rather that the intuitive option of being oriented away. This observation can be exploited together with the normally undesirable Magnus force for the creation of a skyrmion diode. The phenomenon is explained by the increased skyrmion compression resulting from the spin transfer torque opposing the repulsive potential. The smaller skyrmion size then experiences a reduced pinning potential. For practical low-power device applications, we show that the same skyrmion compression can be recreated by applying either a magnetic or electric field. Our analysis provides an insight on the skyrmion dynamics and manipulation that is critical for the realization of skyrmion-based transistors and low-power memory.

  1. Occultifur kilbournensis f.a. sp. nov., a new member of the Cystobasidiales associated with maize (Zea mays) cultivation.

    PubMed

    Kurtzman, Cletus P; Robnett, Christie J

    2015-05-01

    During a study of microorganisms associated with maize (Zea mays) cultivation, yeasts were isolated from overwintered stalks, cobs and surrounding soil, which were collected from an agricultural field in south-central Illinois, USA. Predominant among isolates were two species of Cryptococcus (Cr. flavescens, Cr. magnus) and a red yeast that D1/D2 LSU rRNA gene sequences revealed to be a new species of the basidiomycete yeast genus Occultifur. The species, which was not detected in the same field during the growing season, is described here as Occultifur kilbournensis (MycoBank number MB 811259; type strain NRRL Y-63695, CBS 13982, GenBank numbers, D1/D2 LSU rRNA gene, KP413160, ITS, KP413162; allotype strain NRRL Y-63699, CBS 13983). Mixture of the type and allotype strains resulted in formation of hyphae with clamp connections and a small number of apparent basidia following incubation on 5% malt extract agar at 15 °C for 2 months. In view of the uncertainty of the life cycle, the new species is being designated as forma asexualis. From analysis of D1/D2 and ITS nucleotide sequences, the new species is most closely related to Occultifur externus. PMID:25761862

  2. STS-112/Atlantis/ISS 9A Pre-Launch - Launch On-Orbit - Landing - Crew Egress

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The video starts with an introduction of the crew of Space Shuttle Atlantis on STS-112 at their customary pre-flight meal. The crew consists of Commander Jeffrey Ashby, Pilot Pam Melroy, and Mission Specialists David Wolf, Sandra Magnus, Piers Sellers, and Fyodor Yurchikhin. The crew is then shown during suit-up, while exiting the Operations and Checkout Building to board the Astrovan, and during ingress and seating. Launch views include: Beach Tracker, VAB, PAD-B, Tower-1, DLTR-3, Grandstand, Cocoa Beach DOAMS, Playalinda DOAMS, UCS-23, OTV-170, OTV-171, and External Tank Camera. On-orbit footage includes the Atlantis orbiter docking with the ISS (International Space Station). The video shows clips of extravehicluar activities (EVAs), and some of the tasks performed during the mission. Footage included shows the installation of the S1 Truss onto the ISS with the Space Station Remote Manipulator System (Canadarm 2), Canadarm 2 carrying the Ammonia Tank Assembly prior to connection, the checkout of the Thermal Radiator Rotary Joint, the soft docking of an S-Band antenna, and the deployment of the S1 Radiator. An onboard repair of the ISS humidity separator is also shown. Landing views include: VAB, Tower 1, Mid-Field, Runway South End, Runway North End, Tower-2, Cocoa Beach DOAMS, and PPOV. Kennedy Space Center managers greet the crew upon arrival, and Commander Ashby gives a brief speech while standing with his crew members.

  3. Scaling analysis for the investigation of slip mechanisms in nanofluids

    NASA Astrophysics Data System (ADS)

    Savithiri, S.; Pattamatta, Arvind; Das, Sarit K.

    2011-07-01

    The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.

  4. Quantum tunneling of vortices in two-dimensional condensates

    SciTech Connect

    Auerbach, Assa; Arovas, Daniel P.; Ghosh, Sankalpa

    2006-08-01

    The tunneling rate t{sub v}/({Dirac_h}/2{pi}) of a vortex between two pinning sites (of strength V separated by d) is computed using the Bogoliubov expansion of vortex wave-functions overlap. For BCS vortices, tunneling is suppressed beyond a few Fermi wavelengths. For Bose condensates, t{sub v}=V exp(-{pi}n{sub s}d{sup 2}/2), where n{sub s} is the boson density. The analogy between vortex hopping in a superconducting film and two-dimensional electrons in a perpendicular magnetic field is exploited. We derive the variable range hopping temperature, below which vortex tunneling contributes to magnetoresistance. Using the 'quantum Hall insulator' analogy we argue that the Hall conductivity (rather than the inverse Hall resistivity) measures the effective carrier density in domains of mobile vortices. Details of vortex wave functions and overlap calculations, and a general derivation of the Magnus coefficient for any wave function on the sphere, are provided in appendixes.

  5. Magnification of signatures of a topological phase transition by quantum zero point motion

    NASA Astrophysics Data System (ADS)

    Lopes, Pedro L. e. S.; Ghaemi, Pouyan

    2015-08-01

    We show that the zero point motion of a vortex in superconducting doped topological insulators leads to significant changes in the electronic spectrum at the topological phase transition in this system. This topological phase transition is tuned by the doping level, and the corresponding effects are manifest in the density of states at energies which are on the order of the vortex fluctuation frequency. Although the electronic energy gap in the spectrum generated by a stationary vortex is but a small fraction of the bulk superconducting gap, the vortex fluctuation frequency may be much larger. As a result, this quantum zero point motion can induce a discontinuous change in the spectral features of the system at the topological vortex phase transition to energies which are well within the resolution of scanning tunneling microscopy. This discontinuous change is exclusive to superconducting systems in which we have a topological phase transition. Moreover, the phenomena studied in this paper present effects of Magnus forces on the vortex spectrum which are not present in the ordinary s -wave superconductors. Finally, we demonstrate explicitly that the vortex in this system is equivalent to a Kitaev chain. This allows for the mapping of the vortex fluctuating scenario in three dimensions into similar one-dimensional situations in which one may search for other novel signatures of topological phase transitions.

  6. Antiferromagnetic Skyrmion: Stability, Creation and Manipulation.

    PubMed

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-01-01

    Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topo-logical number Q = ± 1, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials. PMID:27099125

  7. Quantum Hall effect with small numbers of vortices in Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Byrnes, Tim; Dowling, Jonathan P.

    2015-08-01

    When vortices are displaced in Bose-Einstein condensates (BECs), the Magnus force gives the system a momentum transverse in the direction to the displacement. We show that BECs in long channels with vortices exhibit a quantization of the current response with respect to the spatial vortex distribution. The quantization originates from the well-known topological property of the phase around a vortex; it is an integer multiple of 2 π . In a way similar to that of the integer quantum Hall effect, the current along the channel is related to this topological phase and can be extracted from two experimentally measurable quantities: the total momentum of the BEC and the spatial distribution. The quantization is in units of m /2 h , where m is the mass of the atoms and h is Planck's constant. We derive an exact vortex momentum-displacement relation for BECs in long channels under general circumstances. Our results present the possibility that the configuration described here can be used as a novel way of measuring the mass of the atoms in the BEC using a topological invariant of the system. If an accurate determination of the plateaus are experimentally possible, this gives the possibility of a topological quantum mass standard and precise determination of the fine structure constant.

  8. Three-dimensional simulation of the motion of a single particle under a simulated turbulent velocity field

    NASA Astrophysics Data System (ADS)

    Moreno-Casas, P. A.; Bombardelli, F. A.

    2015-12-01

    A 3D Lagrangian particle tracking model is coupled to a 3D channel velocity field to simulate the saltation motion of a single sediment particle moving in saltation mode. The turbulent field is a high-resolution three dimensional velocity field that reproduces a by-pass transition to turbulence on a flat plate due to free-stream turbulence passing above de plate. In order to reduce computational costs, a decoupled approached is used, i.e., the turbulent flow is simulated independently from the tracking model, and then used to feed the 3D Lagrangian particle model. The simulations are carried using the point-particle approach. The particle tracking model contains three sub-models, namely, particle free-flight, a post-collision velocity and bed representation sub-models. The free-flight sub-model considers the action of the following forces: submerged weight, non-linear drag, lift, virtual mass, Magnus and Basset forces. The model also includes the effect of particle angular velocity. The post-collision velocities are obtained by applying conservation of angular and linear momentum. The complete model was validated with experimental results from literature within the sand range. Results for particle velocity time series and distribution of particle turbulent intensities are presented.

  9. Quantum melting of a two-dimensional vortex lattice at zero temperature

    SciTech Connect

    Rozhkov, A.; Stroud, D.

    1996-11-01

    We consider the quantum melting of a two-dimensional flux lattice at temperature {ital T} = 0 in the {open_quote}{open_quote}superclean limit.{close_quote}{close_quote} In this regime, we find that vortex motion is dominated by the Magnus force. A Lindemann criterion predicts melting when {ital n}{sub {ital v}}/{ital n}{sub {ital p}}{ge}{beta}, where {ital n}{sub {ital v}} and {ital n}{sub {ital p}} are the areal number densities of vortex pancakes and Cooper pairs, and {beta}{approx_equal}0.1. A second criterion is derived by using Wigner-crystal and Laughlin wave functions for the solid and liquid phases respectively, and setting the two energies equal. This gives a melting value similar to the Lindemann result. We discuss the numerical value of the {ital T}=0 melting field for thin layers of a low-{ital T}{sub {ital c}} superconductor, such as {ital a}-MoGe, and single layers of high-{ital T}{sub {ital c}} materials. {copyright} {ital 1996 The American Physical Society.}

  10. Behavior of Heavy Particles in Turbulent Channel Flow

    NASA Astrophysics Data System (ADS)

    Lee, Junghoon; Lee, Changhoon

    2010-11-01

    The motion of heavy particles in turbulent channel flow was investigated by using direct numerical simulation. We assumed that Stokes drag, Saffman lift and Magnus lift act on the motion of heavy spherical particles in turbulence. In this study, Stokes number is defined as the particle response time normalized by the wall units. The range of the Stokes number is 0.1˜50 and the diameter of a particle is 0.06˜0.3 in wall unit. Collision of particles with the wall is modelled by an elastic collision. Relevant velocity and acceleration statistics of heavy particles for the given range of Stokes number were investigated to interpret the particle accumulation near the wall. Particle accumulation at the wall is maximized when the Stokes number is around 15. And we found that Saffman lift force has a great effect on particle acceleration in the wall-normal direction near the wall. Detailed statistics including probability density function and autocorrelation of particle velocity and acceleration will be presented in the meeting.

  11. Effects of particle mixing and scattering in the dusty gas flow through moving and stationary cascades of airfoils

    NASA Astrophysics Data System (ADS)

    Tsirkunov, Yu. M.; Romanyuk, D. A.; Panfilov, S. V.

    2011-10-01

    Time-dependent two-dimensional (2D) flow of dusty gas through a set of two cascades of airfoils (blades) has been studied numerically. The first cascade was assumed to move (rotor) and the second one to be immovable (stator). Such a flow can be considered, in some sense, as a flow in the inlet stage of a turbomachine, for example, in the inlet compressor of an aircraft turbojet engine. Dust particle concentration was assumed to be very low, so that the interparticle collisions and the effect of the dispersed phase on the carrier gas were negligible. Flow of the carrier gas was described by full Navier-Stokes equations. In calculations of particle motion, the particles were considered as solid spheres. The particle drag force, transverse Magnus force, and damping torque were taken into account in the model of gas-particle interaction. The impact interaction of particles with blades was considered as frictional and partly elastic. The effects of particle size distribution and particle scattering in the course of particle-blade collisions were investigated. Flow fields of the carrier gas and flow patterns of the particle phase were obtained and discussed.

  12. Maximum group velocity in a one-dimensional model with a sinusoidally varying staggered potential

    NASA Astrophysics Data System (ADS)

    Nag, Tanay; Sen, Diptiman; Dutta, Amit

    2015-06-01

    We use Floquet theory to study the maximum value of the stroboscopic group velocity in a one-dimensional tight-binding model subjected to an on-site staggered potential varying sinusoidally in time. The results obtained by numerically diagonalizing the Floquet operator are analyzed using a variety of analytical schemes. In the low-frequency limit we use adiabatic theory, while in the high-frequency limit the Magnus expansion of the Floquet Hamiltonian turns out to be appropriate. When the magnitude of the staggered potential is much greater or much less than the hopping, we use degenerate Floquet perturbation theory; we find that dynamical localization occurs in the former case when the maximum group velocity vanishes. Finally, starting from an "engineered" initial state where the particles (taken to be hard-core bosons) are localized in one part of the chain, we demonstrate that the existence of a maximum stroboscopic group velocity manifests in a light-cone-like spreading of the particles in real space.

  13. Subsonic Aerodynamics of Spinning and Non-Spinning Type 200 Lightcraft: Progress Report

    NASA Astrophysics Data System (ADS)

    Kenoyer, David A.; Myrabo, Leik N.

    2010-05-01

    A combined experimental and numerical investigation of subsonic aerodynamics for Type 200 laser lightcraft is underway for both spinning and non-spinning cases. A 12.2 cm diameter aluminum model with a "closed" annular airbreathing inlet was fitted to a sting balance in RPI's 61 cm by 61 cm subsonic wind tunnel. Aerodynamic forces and moments were measured first for the non-spinning case vs. angle of attack, at several freestream flow velocities (e.g., 30, 45, and 60 m/s) to assess Reynolds number effects. The CFD analysis was performed for 0-180° angles of attack for a fixed coordinate system (i.e., non-spinning Type 200 model), and predictions compared favorably with the experimental data. In the near future, for the spinning case, a brushless electric motor has been installed to rotate the wind tunnel model at 3000 to 13,000 RPM; Magnus force effects upon the coefficients (Cd, Cl, and Cm) are expected to reveal interesting departures from the non-spinning database in forthcoming experiments.

  14. Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

    NASA Astrophysics Data System (ADS)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

    2014-07-01

    The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

  15. A computational study of golfball aerodynamics: effects of rotation

    NASA Astrophysics Data System (ADS)

    Beratlis, Nikolaos; Squires, Kyle; Balaras, Elias

    2010-11-01

    An efficient finite-difference Navier-Stokes solver is used to carry out a series of simulations of a spinning golfball at three distinct flow regimes: subcritical, critical and super-critical. The golfball is treated using an embedded boundary formulation, where the velocity near the surface is locally reconstructed to satisfy the proper boundary conditions. All scales down to the dimples are resolved by means of direct numerical simulations. Results exhibit all the qualitative flow features that are unique in each regime, namely the drag crisis and the alternation of the Magnus effect. In particular, the key features in each regime are captured and the correct trends are reproduced in all cases, namely a significant drop in the drag coefficient from the sub-critical to the critical regime and a subsequent drop as the Reynolds number gets into the super- critical regime. In addition, the lift exhibits a change in sign from positive to negative values when the Reynolds number increases from sub-critical to critical values. These phenomena are explained in terms of the distinct boundary layer dynamics present in each regime and are further illuminated by flow visualizations.

  16. Universal current-velocity relation of skyrmion motion in chiral magnets

    NASA Astrophysics Data System (ADS)

    Iwasaki, Junichi; Mochizuki, Masahito; Nagaosa, Naoto

    2013-03-01

    Current-driven motion of the magnetic domain wall requires large critical current density jc ~109 -1012 A/m2, at which the joule heating is a serious problem. The skyrmions recently discovered in chiral magnets, on the other hand, have much smaller critical current of jc ~105 -106 A/m2. We present a numerical simulation of the Landau-Lifshitz-Gilbert equation, which reveals a remarkably robust and universal current-velocity relation of the slyrmion motion driven by the spin transfer torque unaffected by either impurities or nonadiabatic effect in sharp contrast to the case of domain wall or spin helix (HL). Simulation results are analyzed using a theory based on Thiele's equation, and it is concluded that this surprising behavior is due to the Magnus force and flexible shape-deformation of individual skyrmions and skyrmion crystal (SkX), which enable them to avoid pinning centers and then weaken the net pinning force. Dynamical deformation of SkX leads to the fluctuation of Bragg peak with large amplitude, which can be detected by the recent neutron-scattering experiment.

  17. Poiseuille flow of a mixture of neutrally buoyant particles in a fluid

    SciTech Connect

    Reinerrsman, P.N.

    1988-01-01

    Constitutive equations are given for the stress, couple stress, and interphase momentum transfer in a mixture consisting of neutrally buoyant particles in a fluid. The interphase momentum transfer terms include objective expressions quantifying Stokes; drag, Faxen force, shear life, Magnus lift, and rotational drag. Coefficients of the drag and lift terms are deduced from macroscopic theory. The viscosity of the solid phase and the cross viscosities are estimated to coincide with previous work in micropolar flow theory. The resulting equations of motion are solved numerically for this general model and for the subset of this model which complies with the principle of phase separation. These solutions are compared with the flows predicted by micropolar theory. Although the micropolar theory may provide a good approximation for multiphase flow in some regimes, micropolar theory cannot model the phase velocity differences and volume fraction gradients that occur in high pressure, small channel flow. The effect of controlling the boundary values of particle and fluid spin is investigated, including the effect of back spin and symmetric spin.

  18. Dissipative preparation of squeezed states with ultracold atomic gases

    NASA Astrophysics Data System (ADS)

    Watanabe, Gentaro; Caballar, Roland Cristopher F.; Diehl, Sebastian; Mäkelä, Harri; Oberthaler, Markus

    2014-05-01

    We present a dissipative quantum state preparation scheme for the creation of phase- and number-squeezed states. It utilizes ultracold atoms in a double-well configuration immersed in a background BEC acting as a dissipative quantum reservoir. We derive a master equation starting from microscopic physics, and show that squeezing develops on a time scale proportional to 1 / N , where N is the number of particles in the double well. This scaling, caused by bosonic enhancement, allows us to make the time scale for the creation of squeezed states very short. Effects of the dephasing which limits the lifetime of the squeezed states can be avoided by stroboscopically switching the driving off and on. We show that this approach leads to robust stationary squeezed states. We also provide the necessary ingredients for a potential experimental implementation. NRF (No. 2012R1A1A2008028), MPS, Korea MEST, FWF (No. F4006-N16), Alfred Kordelin Foundation, Magnus Ehrnrooth Foundation, Emil Aaltonen Foundation, Academy of Finland (No. 251748).

  19. Adiabatic and nonadiabatic perturbation theory for coherence vector description of neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Hollenberg, Sebastian; Päs, Heinrich

    2012-01-01

    The standard wave function approach for the treatment of neutrino oscillations fails in situations where quantum ensembles at a finite temperature with or without an interacting background plasma are encountered. As a first step to treat such phenomena in a novel way, we propose a unified approach to both adiabatic and nonadiabatic two-flavor oscillations in neutrino ensembles with finite temperature and generic (e.g., matter) potentials. Neglecting effects of ensemble decoherence for now, we study the evolution of a neutrino ensemble governed by the associated quantum kinetic equations, which apply to systems with finite temperature. The quantum kinetic equations are solved formally using the Magnus expansion and it is shown that a convenient choice of the quantum mechanical picture (e.g., the interaction picture) reveals suitable parameters to characterize the physics of the underlying system (e.g., an effective oscillation length). It is understood that this method also provides a promising starting point for the treatment of the more general case in which decoherence is taken into account.

  20. Lift hysteresis at stall as an unsteady boundary-layer phenomenon

    NASA Technical Reports Server (NTRS)

    Moore, Franklin K

    1956-01-01

    Analysis of rotating stall of compressor blade rows requires specification of a dynamic lift curve for the airfoil section at or near stall, presumably including the effect of lift hysteresis. Consideration of the magnus lift of a rotating cylinder suggests performing an unsteady boundary-layer calculation to find the movement of the separation points of an airfoil fixed in a stream of variable incidence. The consideration of the shedding of vorticity into the wake should yield an estimate of lift increment proportional to time rate of change of angle of attack. This increment is the amplitude of the hysteresis loop. An approximate analysis is carried out according to the foregoing ideas for a 6:1 elliptic airfoil at the angle of attack for maximum lift. The assumptions of small perturbations from maximum lift are made, permitting neglect of distributed vorticity in the wake. The calculated hysteresis loop is counterclockwise. Finally, a discussion of the forms of hysteresis loops is presented; and, for small reduced frequency of oscillation, it is concluded that the concept of a viscous "time lag" is appropriate only for harmonic variations of angle of attack with time at mean conditions other than maximum lift.

  1. INTERWELL CONNECTIVITY AND DIAGNOSIS USING CORRELATION OF PRODUCTION AND INJECTION RATE DATA IN HYDROCARBON PRODUCTION

    SciTech Connect

    Jerry L. Jensen; Larry W. Lake; Thang D. Bui; Ali Al-Yousef; Pablo Gentil

    2004-08-01

    This report details much of the progress on inferring interwell communication from well rate fluctuations. The goal of the project was to investigate the feasibility of inferring reservoir properties through weights derived from correlations between injection and production rates. We have focused on and accomplished the following items: (1) We have identified two possible causes for the source of negative weights. These are colinearity between injectors, and nonstationarity of be production data. (2) Colinearity has been addressed through ridge regression. Though there is much to be done here, such regression represents a trade-off between a minimum variance estimator and a biased estimator. (3) We have applied the ridge regression and the original Albertoni procedure to field data from the Magnus field. (4) The entire procedure (with several options) has been codified as a spreadsheet add-in. (5) Finally, we have begun, and report on, an extension of the method to predicting oil rates. Successful completion of these items will constitute the bulk of the final year's report.

  2. Universal current-velocity relation of skyrmion motion in chiral magnets

    NASA Astrophysics Data System (ADS)

    Iwasaki, Junichi; Mochizuki, Masahito; Nagaosa, Naoto

    2013-02-01

    Current-driven motion of the magnetic domain wall in ferromagnets is attracting intense attention because of potential applications such as racetrack memory. There, the critical current density to drive the motion is ~109-1012 A m-2. The skyrmions recently discovered in chiral magnets have much smaller critical current density of ~105-106 A m-2, but the microscopic mechanism is not yet explored. Here we present a numerical simulation of Landau-Lifshitz-Gilbert equation, which reveals a remarkably robust and universal current-velocity relation of the skyrmion motion driven by the spin-transfer-torque unaffected by either impurities or nonadiabatic effect in sharp contrast to the case of domain wall or spin helix. Simulation results are analysed using a theory based on Thiele’s equation, and it is concluded that this behaviour is due to the Magnus force and flexible shape-deformation of individual skyrmions and skyrmion crystal, which enable them to avoid pinning centres.

  3. Boattail juncture shaping for spin-stabilized rounds in supersonic flight

    NASA Astrophysics Data System (ADS)

    Jiajan, W.; Chue, R. S. M.; Nguyen, T.; Yu, S. C. M.

    2015-03-01

    In this paper, the effects of boattail junction shaping on aerodynamic drag and stability of supersonic spin-stabilized rounds are investigated using computational fluid dynamics. For a generic round body comprising of a secant-ogive nose, a cylindrical body and a conical boattail, the shaping technique was achieved by adding a convex surface of varying degrees of radius of curvature to the junction between the cylindrical body and the boattail. It was shown through numerical simulations that this shaping technique can provide a reduction in aerodynamic drag of up to 5.4 % without destabilizing the round bodies when the radius of curvature is less than 8.8 times the diameter of the cylindrical body. The more gradual change of the flow characteristics, e.g., the pressure over the convex surface, was identified as the main reason for the drag reduction. A unique aspect of the current work is that stability is treated as an integral part of the performance assessment. It was also found that the dynamic instability encountered at large radii of curvature is due to the Magnus effects.

  4. Wave-vortex interactions in the nonlinear Schrödinger equation

    NASA Astrophysics Data System (ADS)

    Guo, Yuan; Bühler, Oliver

    2014-02-01

    This is a theoretical study of wave-vortex interaction effects in the two-dimensional nonlinear Schrödinger equation, which is a useful conceptual model for the limiting dynamics of superfluid quantum condensates at zero temperature. The particular wave-vortex interaction effects are associated with the scattering and refraction of small-scale linear waves by the straining flows induced by quantized point vortices and, crucially, with the concomitant nonlinear back-reaction, the remote recoil, that these scattered waves exert on the vortices. Our detailed model is a narrow, slowly varying wavetrain of small-amplitude waves refracted by one or two vortices. Weak interactions are studied using a suitable perturbation method in which the nonlinear recoil force on the vortex then arises at second order in wave amplitude, and is computed in terms of a Magnus-type force expression for both finite and infinite wavetrains. In the case of an infinite wavetrain, an explicit asymptotic formula for the scattering angle is also derived and cross-checked against numerical ray tracing. Finally, under suitable conditions a wavetrain can be so strongly refracted that it collapses all the way onto a zero-size point vortex. This is a strong wave-vortex interaction by definition. The conditions for such a collapse are derived and the validity of ray tracing theory during the singular collapse is investigated.

  5. Floquet spin states in graphene under ac-driven spin-orbit interaction

    NASA Astrophysics Data System (ADS)

    López, A.; Sun, Z. Z.; Schliemann, J.

    2012-05-01

    We study the role of periodically driven time-dependent Rashba spin-orbit coupling (RSOC) on a monolayer graphene sample. After recasting the originally 4×4 system of dynamical equations as two time-reversal related two-level problems, the quasienergy spectrum and the related dynamics are investigated via various techniques and approximations. In the static case, the system is gapped at the Dirac point. The rotating wave approximation (RWA) applied to the driven system unphysically preserves this feature, while the Magnus-Floquet approach as well as a numerically exact evaluation of the Floquet equation show that this gap is dynamically closed. In addition, a sizable oscillating pattern of the out-of-plane spin polarization is found in the driven case for states that are completely unpolarized in the static limit. Evaluation of the autocorrelation function shows that the original uniform interference pattern corresponding to time-independent RSOC gets distorted. The resulting structure can be qualitatively explained as a consequence of the transitions induced by the ac driving among the static eigenstates, i.e., these transitions modulate the relative phases that add up to give the quantum revivals of the autocorrelation function. Contrary to the static case, in the driven scenario, quantum revivals (suppressions) are correlated to spin-up (down) phases.

  6. Antiferromagnetic Skyrmion: Stability, Creation and Manipulation

    NASA Astrophysics Data System (ADS)

    Zhang, Xichao; Zhou, Yan; Ezawa, Motohiko

    2016-04-01

    Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topo-logical number Q = ± 1, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials.

  7. Symmetry breaking and singularity structure in Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Commeford, K. A.; Garcia-March, M. A.; Ferrando, A.; Carr, Lincoln D.

    2012-08-01

    We determine the trajectories of vortex singularities that arise after a single vortex is broken by a discretely symmetric impulse in the context of Bose-Einstein condensates in a harmonic trap. The dynamics of these singularities are analyzed to determine the form of the imprinted motion. We find that the symmetry-breaking process introduces two effective forces: a repulsive harmonic force that causes the daughter trajectories to be ejected from the parent singularity and a Magnus force that introduces a torque about the axis of symmetry. For the analytical noninteracting case we find that the parent singularity is reconstructed from the daughter singularities after one period of the trapping frequency. The interactions between singularities in the weakly interacting system do not allow the parent vortex to be reconstructed. Analytic trajectories were compared to the actual minima of the wave function, showing less than 0.5% error for an impulse strength of v=0.00005. We show that these solutions are valid within the impulse regime for various impulse strengths using numerical integration of the Gross-Pitaevskii equation. We also show that the actual duration of the symmetry-breaking potential does not significantly change the dynamics of the system as long as the strength is below v=0.0005.

  8. First oilfields of the Central and Northern North Sea

    SciTech Connect

    Swarbrick, R.E. ); Martin, J.A. )

    1991-03-01

    Only 25 years ago the areas now termed the Central and Northern North Sea were the true frontier exploration basins. Stratigraphy and structure were essentially unknown, except inferences drawn from the Mesozoic outcrops of Britain and Denmark. At that time the majority of small British onshore oil fields were reservoired in Paleozoic strata. In the Central North Sea, oil was first discovered in Paleocene deep-water sandstone and Upper Cretaceous chalk reservoirs. The first commercial reserves were proven with the discovery of the Ekofisk field (Upper Cretaceous) in 1969 and Forties field (Paleocene) in 1970, both now classed as giants. Subsequently stratigraphically deeper reservoirs were established, including Jurassic sandstones (Piper field) and Permian carbonates and sandstones (Auk and Argyll fields). Diversity of trap type and reservoir age is now a hallmark of the Central North Sea basin. In the Northern North Sea, the first exploration well in 1971 on the Brent field structure, a true wildcat whose nearest UK well control was 320 mi to the south, found oil in Middle Jurassic deltaic sandstones. A spate of discoveries on similar tilted fault blocks with Middle Jurassic and underlying Triassic alluvial-fluvial sandstone targets followed. Later, Upper Jurassic deep-water sandstones became established as a further significant reservoir with the Brae field and Magnus field discoveries. Original seismic data, well prognoses, and structure maps tell the story of these early discoveries. Public response in Norway and the UK to the emergence of the North Sea oil province on their doorstep will be reviewed.

  9. Mechanical model of the Lorentz force and Coulomb interaction

    NASA Astrophysics Data System (ADS)

    Dmitriyev, Valery

    2008-09-01

    The centripetal and Coriolis accelerations experienced by a cart traveling over a rotating turntable are usually calculated proceeding from the known kinematics of the problem. Respective forces can be regarded as due to the entrainment of the cart in the moving solid environs. We extend the approach to the general case of a particle entrained in the flow of the surrounding medium. The expression for the driving force on the particle obtained from the kinematics of the entrainment prescribed appears to be isomorphic to the Lorentz and Coulomb force on a positive electric charge. The inverse direction of the electromagnetic force on a negative charge implies that a growing applied flow induces the upstream motion of the particle. A possible microscopic mechanism for it may be the Magnus force dynamics of a kink in a vortex tangle. The loop on a straight vortex filament can be taken as a model of the electron, the loop with a cavitation models the positron. The Lorentz force is concerned with the Coriolis acceleration. The Coulomb interaction is due to the centripetal or centrifugal force that arises in the turbophoresis of the kink in the perturbation field generated in the medium by the center of pressure.

  10. [Effect of the destruction of the brain serotoninergic system on the alcohol consumption by rats in the early periods of experimental alcoholism].

    PubMed

    Zhukov, V N; Varkov, A I; Burov, Iu V

    1985-05-01

    Albino noninbred rats were divided into groups, according to the duration of alcoholic anesthesia (4.5 g/kg i.p.), of predisposed (195.6 min) and non-predisposed (69.1 min) to voluntary intake of alcohol. Another group included animals screened for 21 days according to the level of intake of 15% ethanol under the conditions of free choice between alcohol and water (6.15 and 2.62 g/kg pure ethanol per day, respectively). The animals were subjected to electro-coagulation of the dorsal or magnus raphe nucleus or were injected with 5,6-dihydroxytryptamine--DNT (75 micrograms/microliters) into the ventricles of the brain. It was established that in rats non-predisposed to alcohol intake, the destruction of the raphe nuclei, of the dorsal in particular, or injection of DOT to animals with a weak alcoholic motivation produces a dramatic increase in alcohol intake. In alcohol intake predisposed rats and in animals with a high level of alcohol use, analogous exposures do not bring about any significant differences in alcohol intake. The data obtained indicate that the reduced serotonin content in the brain is associated with an increase in the level of alcoholic motivation. PMID:4039957

  11. Rotylenchus castilloi n. sp. (Nematoda: Hoplolaimidae), a new species with long stylet from northern Iran.

    PubMed

    Talezari, Atefeh; Pourjam, Ebrahim; Kheiri, Ahmad; Liébanas, Gracia; Aliramaji, Farzad; Pedram, Majid; Rezaee, Saeed; Atighi, Mohammad Reza

    2015-01-01

    Rotylenchus castilloi n. sp., a new bisexual species is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by having a hemispherical, continuous lip region with an irregular corncob-like appearance under SEM, very long stylet (62-68 µm), vulva located at 49.7-62.2% of body length from anterior end, with a protruding double epiptygma, a rounded to convex-conoid (rarely bi-lobed) tail with 8-12 annuli and specific sequences of D2-D3 segments of 28S and ITS1-rRNA genes. Differences between the new species and four other species of the genus (R. mesorobustus, R. cazorlaensis, R. magnus and R. jaeni) are discussed. Morphologically, the new species can be separated from these species mostly by its body length, lip region characters, stylet length and location of phasmid. Phylogenetic analyses using 721 bp partial sequences of D2-D3 expansion segments of the 28S and 590 bp ITS1-rRNA genes revealed the new species forming a clade with two isolates of R. eximius and two isolates of R. unisexus, two morphologically unrelated species. PMID:25781816

  12. Affinity purification and characterization of a biodegradable plastic-degrading enzyme from a yeast isolated from the larval midgut of a stag beetle, Aegus laevicollis.

    PubMed

    Suzuki, Ken; Sakamoto, Hironori; Shinozaki, Yukiko; Tabata, Jun; Watanabe, Takashi; Mochizuki, Atsushi; Koitabashi, Motoo; Fujii, Takeshi; Tsushima, Seiya; Kitamoto, Hiroko K

    2013-09-01

    Two yeast strains, which have the ability to degrade biodegradable plastic films, were isolated from the larval midgut of a stag beetle, Aegus laevicollis. Both of them are most closely related to Cryptococcus magnus and could degrade biodegradable plastic (BP) films made of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) effectively. A BP-degrading enzyme was purified from the culture broth of one of the isolated strains employing a newly developed affinity purification method based on the binding action of the enzyme to the substrate (emulsified PBSA) and its subsequent degradative action toward the substrate. Partial amino acid sequences of this enzyme suggested that it belongs to the cutinase family, and thus, the enzyme was named CmCut1. It has a molecular mass of 21 kDa and a degradative activity for emulsified PBSA which was significantly enhanced by the simultaneous presence of Ca(2+) or Mg(2+) at a concentration of about 2.5 mM. Its optimal pH was 7.5, and the optimal temperature was 40 °C. It showed a broad substrate specificity for p-nitrophenyl (pNP)-fatty acid esters ranging from pNP-acetate (C2) to pNP-stearate (C18) and films of PBSA, PBS, poly(ε-caprolactone), and poly(lactic acid). PMID:23224497

  13. STS-112 crew practices emergency egress training during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- During emergency egress training from the launch pad, the STS-112 crew listens to a trainer about use of the system. The crew members are, from left in the center, Commander Jeffrey Ashby, Mission Specialists Sandra Magnus, Piers Sellers and Fyodor Yurchikhin; and Pilot Pamela Melroy. In the foreground, left, is Mission Specialist David Wolf. Yurchikhin is with the Russian Space Agency. The training is part of Terminal Countdown Demonstration Test activities, which include a simulated launch countdown. Mission STS-112 aboard Space Shuttle Atlantis is scheduled to launch no earlier than Oct. 2, between 2 and 6 p.m. EDT. STS-112 is the 15th assembly mission to the International Space Station. Atlantis will be carrying the S1 Integrated Truss Structure, the first starboard truss segment, to be attached to the central truss segment, S0, and the Crew and Equipment Translation Aid (CETA) Cart A. The CETA is the first of two human-powered carts that will ride along the ISS railway, providing mobile work platforms for future spacewalking astronauts.

  14. [Arthur Simons on tonic neck reflexes in persons with hemiplegia. From the years 1916 to 1919].

    PubMed

    Holdorff, B

    2012-04-01

    Tonic neck reflexes described in 1921 by Magnus and deKlejn in animals and men were studied in hemiplegic patients who were mainly victims of WWI by Arthur Simons, a neurologist in Berlin and coworker of Hermann Oppenheim. The effect of the asymmetric neck reflexes after head rotation was restricted to the paralyzed side: tonus (spasms) of extension and adduction during mid-position of the head or head version to the paralyzed side; flexion tonus and abduction during head version to the non-paralyzed side; and flexion tonus (spasms) of the paralyzed limbs during flexion of the head and extension spasms by head extension. More than this, hemiplegic "Mitbewegungen" or associated reactions (Walshe) were observed. They are elicited by conscious innervations of the unaffected side, e.g. by fist closure, and are increased or varied by head rotation, the tonic neck reflexes. They occurred in 25%. A film with Arthur Simons as examiner from the years 1916-1919 shows these nearly forgotten phenomena. Their everyday significance was already stressed in 1920, long before the rules of antispastic positions were defined by Bobath. PMID:21845452

  15. Selectivity in multiple quantum nuclear magnetic resonance

    SciTech Connect

    Warren, W.S.

    1980-11-01

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible.

  16. C-fos expression in the pons and medulla of the cat during carbachol-induced active sleep.

    PubMed

    Yamuy, J; Mancillas, J R; Morales, F R; Chase, M H

    1993-06-01

    Microinjection of carbachol into the rostral pontine tegmentum of the cat induces a state that is comparable to naturally occurring active (REM, rapid eye movement) sleep. We sought to determine, during this pharmacologically induced behavioral state, which we refer to as active sleep-carbachol, the distribution of activated neuron within the pons and medulla using c-fos immunocytochemistry as a functional marker. Compared with control cats, which were injected with saline, active sleep-carbachol cats exhibited higher numbers of c-fos-expressing neurons in (1) the medial and portions of the lateral reticular formation of the pons and medulla, (2) nuclei in the dorsolateral rostral pons, (3) various raphe nuclei, including the dorsal, central superior, magnus, pallidus, and obscurus, (4) the medial and lateral vestibular, prepositus hypoglossi, and intercalatus nuclei, and (5) the abducens nuclei. On the other hand, the mean number of c-fos-expressing neurons found in the masseter, facial, and hypoglossal nuclei was lower in carbachol-injected than in control cats. The data indicate that c-fos expression can be employed as a marker of state-dependent neuronal activity. The specific sites in which there were greater numbers of c-fos-expressing neurons during active sleep-carbachol are discussed in relation to the state of active sleep, as well as the functional role that these sites play in generating the various physiological patterns of activity that occur during this state. PMID:8501533

  17. Exfoliative cytology of buccal squames: A quantitative cytomorphometric analysis of patients with diabetes

    PubMed Central

    Sankhla, Bharat; Sharma, Abhishek; Shetty, Raju Singam; Bolla, Sheetal Chowdary; Gantha, Naga Sribala; Reddy, Prasun

    2014-01-01

    Background: Diabetes is a third leading cause of mortality and morbidity in the world. Diabetes is one of the most common endocrine metabolic disorders and its prevalence has been increasing worldwide. Oral exfoliative cytology may be a more appropriate adjunctive diagnostic tool in conditions like diabetes mellitus, where the invasive techniques lose viability. Aims: The purpose of this study is to analyze the cytomorphometric changes in the exfoliated cells of the oral mucosa, as an adjunct to the diagnosis of diabetes. Materials and Methods: Smears were taken from the buccal mucosa of 30 diabetes patients (study group) and 30 healthy individuals (control group). All the smears were stained with rapid Papanicolaou stain (PAP). In the PAP smears, the nuclear area (NA), cytoplasmic area (CA), and cytoplasmic-to-nuclear ratio (CNR) were evaluated for 50 cells in each smear, using the Image Analysis Software (Magnus Pro™) and research microscope (Lawrence and Mayo™). Results: The results showed that the mean NA was significantly higher (P < 0.001) in the study group, whereas, the mean CA did not exhibit a statistically significant difference (P > 0.001). The mean CNR was significantly lower in the study group (P < 0.001). Interpretation and Conclusion: The results associated with the clinical observations suggest that diabetes can produce morphological and functional alterations in the oral epithelial cells, detectable by microscopic and cytomorphometric analysis using exfoliative cytology, which can be used in the diagnosis of the disease. PMID:25374837

  18. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    González-Tizón, Ana M.; Rojo, Verónica; Vierna, Joaquín; Jensen, K. Thomas; Egea, Emilie; Martínez-Lage, Andrés

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linné 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  19. The personal is scientific: Women, gender, and the production of sexological knowledge in Germany and Austria, 1900-1931.

    PubMed

    Leng, Kirsten

    2015-08-01

    This article addresses the roles women and gender played in the production of sexological knowledge in the early 20th century, particularly in German-speaking Europe. Although existing scholarship focuses almost exclusively on the work of "founding fathers" such as Richard von Krafft-Ebing and Magnus Hirschfeld, women in fact made important contributions to the field. Based on analysis of texts written between 1900 and 1931, this article shows how women were able to successfully mobilize their gender as a privileged form of "situated knowledge," and thereby assert their authority over and superior insights into certain subject areas, namely, female sexualities and sexual difference. At the same time, however, this article also highlights the constraints upon women's gendered standpoint. It shows that women's sexological writing was not just informed by their gender but also by their class and race. Moreover, because gender threatened to cast their work as insufficiently objective and scientific, women cleaved to sexology's rules of evidence and argumentation, and adopted the field's ideological trappings in order to participate in discursive contestations over sexual truths. By interrogating gender, this article introduces much-needed nuance into existing understandings of sexology, and reframes sexology itself as a site wherein new sexual subjectivities were imagined, articulated, and debated. However, it also raises fundamental questions about women sexologists' capacity to create knowledge about women and female sexualities that was truer, more correct, and more authentic than that produced by men. PMID:26375153

  20. Detection of yeast species also occurring in substrates associated with animals and identification of a novel dimorphic species in Verbascum flowers from Georgia.

    PubMed

    Sipiczki, Matthias

    2013-03-01

    The molecular taxonomic analysis of yeasts isolated from Verbascum flowers collected in central Georgia identified strains that could be assigned to the species Cryptococcus adeliensis, Cryptococcus magnus and Moniliella megachiliensis detected previously also in substrates associated with insects and other animals and a hitherto undescribed species for which the name Candida verbasci is proposed. The new species forms slightly pink colonies, propagates by mostly unipolar budding, forms invasive pseudomycelium, and the sequences of its D1/D2 LSU rRNA genes and ITS1-5.8S-ITS2 regions indicate close phylogenetic relationship with a group of species that form a cluster basal to the Candida albicans/Lodderomyces elongisporus clade. The type strain is 11-1055(T). It has been deposited in Centralbureau voor Schimmelcultures (Utrecht, the Netherlands) as CBS 12699(T), the National Collection of Agricultural and Industrial Microorganisms (Budapest, Hungary) as NCAIM Y.02048(T) and the Culture Collection of Yeasts (Bratislava, Slovakia) as CCY 29-185-1(T). The GenBank accession numbers for nucleotide sequences of the C. verbasci type strain are: JX515981 (D1/D2 domain of the 26S rRNA gene) and JX515982 (ITS1-5.8S-ITS2). Mycobank: MB 801391. PMID:23114573

  1. The Serotonergic Anatomy of the Developing Human Medulla Oblongata: Implications for Pediatric Disorders of Homeostasis

    PubMed Central

    Kinney, Hannah C.; Broadbelt, Kevin G.; Haynes, Robin L.; Rognum, Ingvar J.; Paterson, David S.

    2011-01-01

    The caudal serotonergic (5-HT) system is a critical component of a medullary “homeostatic network” that regulates protective responses to metabolic stressors such as hypoxia, hypercapnia, and hyperthermia. We define anatomically the caudal 5-HT system in the human medulla as 5-HT neuronal cell bodies located in the raphé (raphé obscurus, raphé magnus, and raphé pallidus), extra-raphé (gigantocellularis, paragigantocellularis lateralis, intermediate reticular zone, lateral reticular nucleus, and nucleus subtrigeminalis), and ventral surface (arcuate nucleus). These 5-HT neurons are adjacent to all of the respiratory- and autonomic-related nuclei in the medulla where they are positioned to modulate directly the responses of these effector nuclei. In the following review, we highlight the topography and development of the caudal 5-HT system in the human fetus and infant, and its inter-relationships with nicotinic, GABAergic, and cytokine receptors. We also summarize pediatric disorders in early life which we term “developmental serotonopathies” of the caudal (as well as rostral) 5-HT domain and which are associated with homeostatic imbalances. The delineation of the development and organization of the human caudal 5-HT system provides the critical foundation for the neuropathologic elucidation of its disorders directly in the human brain. PMID:21640183

  2. Matrix operator approach to the quantum evolution operator and the geometric phase

    NASA Astrophysics Data System (ADS)

    Kim, Sang Pyo; Kim, Jewan; Soh, Kwang Sup

    2013-11-01

    The Moody-Shapere-Wilczek's adiabatic effective Hamiltonian and Lagrangian method is developed further into the matrix effective Hamiltonian (MEH) and Lagrangian (MEL) approach to a parameter-dependent quantum system. The matrix-operator approach formulated in the product integral (PI) provides not only a method to find the wave function efficiently in the MEH approach but also higher order corrections to the effective action systematically in the MEL approach, a la the Magnus expansion and the Kubo cumulant expansion. A coupled quantum system of a light particle of a harmonic oscillator is worked out, and as a by-product, a new kind of gauge potential (Berry's connection) is found even for nondegenerate cases (real eigenfunctions). Moreover, in the PI formulation the holonomy of the induced gauge potential is related to Schlesinger's exact formula for the gauge field tensor. A superadiabatic expansion is also constructed, and a generalized Dykhne formula, depending on the contour integrals of the homotopy class of complex degenerate points, is rephrased in the PI formulation.

  3. Research of the gas-solid flow character based on the DEM method

    NASA Astrophysics Data System (ADS)

    Wang, Xueyao; Xiao, Yunhan

    2011-12-01

    Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM). Euler method and Lagrange method are employed to deal with the gas phase and solid phase respectively. The collided force among particles, striking force between particle and wall, drag force, gravity, Magnus lift force and Saffman lift force are considered when establishing the mathematic models. Soft-sphere model is used to describe the collision of particles. In addition, the Euler method is also used for modeling the solid phase to compare with the results of DEM. The flow patterns, particle mean velocities, particles' diffusion and pressure drop of the bed under typical operating conditions are obtained. The results show that the DEM method can describe the detailed information among particles, while the Euler-Euler method cannot capture the micro-scale character. No matter which method is used, the diffusion of particles increases with the increase of gas velocity. But the gathering and crushing of particles cannot be simulated, so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is larger. In addition, it is shown by DEM method, with strengthening of the carrying capacity, more and more particles can be schlepped upward and the dense suspension upflow pattern can be formed. However, the results given by the Euler-Euler method are not consistent with the real situation.

  4. Cardiocentric neurophysiology: the persistence of a delusion.

    PubMed

    Smith, C U M

    2013-01-01

    Aristotle is well known to have taught that the brain was a mere coolant apparatus for overheated blood and to have located the hegemonikon in the heart. This teaching was hotly disputed by his immediate successors in the Alexandrian Museum, who showed that the brain played the central role in psychophysiology. This was accepted and developed by the last great biomedical figure of classical antiquity - Claudius Galen. However, Aristotle's cardiocentric theory did not entirely disappear and this article traces its influence through the Arabic physicians of the Islamic ascendancy, into the European Middle Ages where Albertus Magnus' attempt to reconcile cardiocentric and cerebrocentric physiology was particularly influential. It shows how cardiocentricity was sufficiently accepted to attract the attention of, and require refutation by, many of the great names of the Renaissance, including Vesalius, Fernel, and Descartes, and was still taken seriously by luminaries such as William Harvey in the mid-seventeenth century. The article, in rehearsing this history, shows the difficulty of separating the first-person perspective of introspective psychology and the third-person perspective of natural science. It also outlines an interesting case of conflict between philosophy and physiology. PMID:23323528

  5. Wave–vortex interactions in the nonlinear Schrödinger equation

    SciTech Connect

    Guo, Yuan Bühler, Oliver

    2014-02-15

    This is a theoretical study of wave–vortex interaction effects in the two-dimensional nonlinear Schrödinger equation, which is a useful conceptual model for the limiting dynamics of superfluid quantum condensates at zero temperature. The particular wave–vortex interaction effects are associated with the scattering and refraction of small-scale linear waves by the straining flows induced by quantized point vortices and, crucially, with the concomitant nonlinear back-reaction, the remote recoil, that these scattered waves exert on the vortices. Our detailed model is a narrow, slowly varying wavetrain of small-amplitude waves refracted by one or two vortices. Weak interactions are studied using a suitable perturbation method in which the nonlinear recoil force on the vortex then arises at second order in wave amplitude, and is computed in terms of a Magnus-type force expression for both finite and infinite wavetrains. In the case of an infinite wavetrain, an explicit asymptotic formula for the scattering angle is also derived and cross-checked against numerical ray tracing. Finally, under suitable conditions a wavetrain can be so strongly refracted that it collapses all the way onto a zero-size point vortex. This is a strong wave–vortex interaction by definition. The conditions for such a collapse are derived and the validity of ray tracing theory during the singular collapse is investigated.

  6. The Evolutionary Implications of Hemipenial Morphology of Rattlesnake Crotalus durissus terrificus (Laurent, 1768) (Serpentes: Viperidae: Crotalinae)

    PubMed Central

    Porto, Marcovan; de Oliveira, Marco Antonio; Pissinatti, Lorenzo; Rodrigues, Renata Lopes; Rojas-Moscoso, Julio Alejandro; Cogo, José Carlos; Metze, Konradin; Antunes, Edson; Nahoum, César; Mónica, Fabíola Z.; De Nucci, Gilberto

    2013-01-01

    Most amniotes vertebrates have an intromittent organ to deliver semen. The reptile Sphenodon and most birds lost the ancestral penis and developed a cloaca-cloaca mating. Known as hemipenises, the copulatory organ of Squamata shows unique features between the amniotes intromittent organ. They are the only paired intromittent organs across amniotes and are fully inverted and encapsulated in the tail when not in use. The histology and ultrastructure of the hemipenes of Crotalus durissus rattlesnake is described as the evolutionary implications of the main features discussed. The organization of hemipenis of Crotalus durissus terrificus in two concentric corpora cavernosa is similar to other Squamata but differ markedly from the organization of the penis found in crocodilians, testudinata, birds and mammals. Based on the available data, the penis of the ancestral amniotes was made of connective tissue and the incorporation of smooth muscle in the framework of the sinusoids occurred independently in mammals and Crotalus durissus. The propulsor action of the muscle retractor penis basalis was confirmed and therefore the named should be changed to musculus hemipenis propulsor.The retractor penis magnus found in Squamata has no homology to the retractor penis of mammals, although both are responsible for the retraction of the copulatory organ. PMID:23840551

  7. Specific features of the dynamics of epiphytic and soil yeast communities in the thickets of Indian balsam on mucky gley soil

    NASA Astrophysics Data System (ADS)

    Glushakova, A. M.; Kachalkin, A. V.; Chernov, I. Yu.

    2011-08-01

    The annual dynamics of the number and taxonomic composition of yeast communities were studied in the phyllosphere, on the flowers, and on the roots of Indian balsam ( Impatiens glandulifera Royle) and in the mucky gley soil under the thickets of this plant. It was shown that typical phyllosphere yeast communities with a predominance of the red-pigmented species Rhodotorula mucilaginosa and Rhodotorula glutinis and the typical epiphyte Cryptococcus magnus are formed on the leaves of this annual hygrophyte. However, yeast groups with a predominance of the ascosporous species Saccharomyces paradoxus, Kazachstania barnettii, and Torulaspora delbrueckii, which are not typical of soils at all, were found in the mucky gley soil under the thickets of Indian balsam. Thus, the epiphytic and soil yeast complexes under the thickets of Indian balsam are represented by two entirely discrete communities without common species. In other biogeocenoses of the forest zone, the rearrangement of the structure of yeast communities in passing from the aboveground substrates to the soil proceeds gradually, and most of the species can be isolated both from the aboveground parts of plants and from the soil. The strong difference between the yeast communities in the phyllosphere of Indian balsam and in the soil under its thickets is apparently related to the fact that the annual hygrophytes are decomposed very quickly (during several days after the first frosts). Because of this, an intermediate layer between the phyllosphere and the soil (the litter layer), in which epiphytic microorganisms can develop, is not formed under these plants.

  8. Effectiveness of Selected Fitness Exercises on Stress of Femoral Neck using Musculoskeletal Dynamics Simulations and Finite Element Model.

    PubMed

    Qian, Jing-Guang; Li, Zhaoxia; Zhang, Hong; Bian, Rong; Zhang, Songning

    2014-06-28

    The purpose of the study was to establish a dynamics model and a three-dimensional (3D) finite element model to analyze loading characteristics of femoral neck during walking, squat, single-leg standing, and forward and lateral lunges. One male volunteer performed three trials of the five movements. The 3D kinematic data were captured and imported into the LifeMOD to establish a musculoskeletal dynamics model to obtain joint reaction and muscle forces of iliacus, gluteus medius, gluteus maximus, psoas major and adductor magnus. The loading data LfeMOD were imported and transformed into a hip finite-element model. The results of the finite element femur model showed that stress was localized along the compression arc and the tension arc. In addition, the trabecular bone and tension lines of the Ward's triangle also demonstrated high stress. The compact bone received the greatest peak stress in the forward lunge and the least stress in the squat. However, the spongy bone in the femoral neck region had the greatest stress during the walk and the least stress in the squat. The results from this study indicate that the forward lunge may be an effective method to prevent femoral neck fractures. Walking is another effective and simple method that may improve bone mass of the Ward's triangle and prevent osteoporosis and femoral neck fracture. PMID:25114732

  9. Neurons of the ventral medulla oblongata that contain both somatostatin and enkephalin immunoreactivities project to nucleus tractus solitarii and spinal cord.

    PubMed

    Millhorn, D E; Seroogy, K; Hökfelt, T; Schmued, L C; Terenius, L; Buchan, A; Brown, J C

    1987-10-20

    The ventral aspect of the medulla oblongata of colchicine-treated rats was examined immunohistochemically using mouse monoclonal antibodies raised against somatostatin (SOM) and rabbit polyclonal antibodies to methionine enkephalin (ENK). Numerous perikarya showed positive immunostaining for both antisera. For the most part, the double-labelled cells were located (1) along the ventrolateral surface in a region that corresponds to nucleus paragigantocellularis, (2) in the region of nucleus gigantocellularis-nucleus raphe magnus and (3) in a discrete area just above the inferior olivary nucleus. In an attempt to determine the projection sites of the SOM/ENK somata, the retrogradely transported fluorescent dye Fluoro-Gold was injected into either the nucleus tractus solitarii (NTS) or the upper part of the thoracic spinal cord. SOM/ENK cells in all 3 regions were labelled by dye administered into the spinal cord whereas only those SOM/ENK cells located in nucleus paragigantocellularis were stained by dye microinjected into NTS. This is the first evidence of a SOM/ENK projection from the ventral medulla to either the spinal cord or NTS. PMID:2446706

  10. The antinociceptive action of etorphine in the dorsal horn is due to a direct spinal action and not to activation of descending inhibition.

    PubMed Central

    Clark, S. L.; Ryall, R. W.

    1983-01-01

    1--Etorphine, microinjected into the brainstem or administered intravenously, inhibited the firing of dorsal horn neurones to noxious heat in spinal or non-spinal anaesthetized cats and in decerebrate, non-anaesthetized cats with intact spinal cords. 2--Small doses of etorphine sometimes caused facilitation, especially when the cord was intact, but this was invariably followed by inhibition at higher doses. 3--The ED50 for inhibition (mean 3.9 micrograms/kg) after microinjection into nucleus raphe magnus, nucleus reticularis magnocellularis or the lateral tegmental field was similar at all sites in anaesthetized, non-spinal cats. 4--The ED50 for microinjection was not increased by spinal transection in anaesthetized cats (mean ED50, 2.6 micrograms/kg) and was similar to the ED50 in decerebrate, non-anaesthetized cats. 5--Intravenous administration was 2 to 3 times more effective than microinjection and the time course of inhibition was faster after intravenous administration than after microinjection. 6--It is concluded that etorphine inhibits dorsal horn neurones after microinjection or intravenous administration by a direct action on the spinal cord and not by activating a descending inhibition. After microinjection it rapidly enters the general circulation and subsequently distributes into the spinal cord. 7--It is also concluded that naloxone readily gains entry to the circulation from the brain because microinjection antagonized the effects of systemic etorphine on dorsal horn neurones in spinal cats. PMID:6338986

  11. Medial Patellofemoral Ligament Reconstruction in Skeletally Immature Patients

    PubMed Central

    Yercan, Hüseyin Serhat; Kale, Gürler; Erkan, Serkan; Özalp, Taçkın; Okcu, Güvenir

    2014-01-01

    Objectives: To evaluate the clinical outcome after medial patellofemoral ligament (MPFL) reconstruction for patellofemoral instability in skeletally immature patients. Methods: Study participants were 8 patients ( median age, 10 years; range, 5-14 and one male , others female) who had suffered from persistent patellofemoral instability. Our technique preserves femoral and patellar insertion anatomy of MPFL using a free semitendinosus autograft, together with tenodesis to the adductor magnus tendon thus sparing the open physis of distal femur and the patellar attachment of MPFL. The clinical results were evaluated preoperatively and the final follow-up period using the Kujala patellofemoral score. Patellar shift, tilt and height were measured preoperatively and on the latest follow-up on plain radiographs. Results: At average 42 months follow-up ( range, 16 to 56), %80 of patients were satisfied with the treatment. Redislocation or instability symptoms occurred in two patients. No apprehension signs or redislocations were seen in the remanining six patients. A significant improvement (p‹0.05) in Kujala score (from 36 to 77) was found. Patellar shift & tilt decreased to anatomic values in six patients but patella alta persisted. Conclusion: The result of this study show that MPFL reconstruction with our technique seems to be an effective treatment for recurrent and habitual patellofemoral dislocation in skeletally immature patients; leading to significant increases in stability and functionality.

  12. Numerical study on the aerodynamics of a golf ball and its comparison with a smooth sphere

    NASA Astrophysics Data System (ADS)

    Li, Jing; Tsubokura, Makoto; Tsunoda, Masaya

    2014-11-01

    The present study has numerically investigated the flow over a golf ball and a smooth sphere by conducting large-eddy simulation (LES) using hundreds of millions of unstructured elements. Simulations were conducted at various Reynolds numbers ranging from the subcritical to the supercritical regimes. Special attention was paid to the phenomenon of drag crisis as well as the effect of surface roughness on the drag crisis. The simulation result shows that the surface roughness introduced by the dimples of the golf ball causes a local instability of the flow around the ball and subsequently leads to a momentum transfer in the near-wall region inside the dimples. The flow with high momentum in the near-wall region travels further downstream, which consequently results in the drag crisis occurring at a relatively lower Reynolds number compared with that of the smooth sphere. Moreover, the Magnus effect resulting from the rotating motion of a sphere was also one of the main concerns in this study. The simulation result shows that lift forces are imposed on both the rotating smooth sphere and rotating golf ball. For most cases the lift force points to the positive direction, however, the negative lift force appears also under certain conditions.

  13. A general transfer-function approach to noise filtering in open-loop quantum control

    NASA Astrophysics Data System (ADS)

    Viola, Lorenza

    2015-03-01

    Hamiltonian engineering via unitary open-loop quantum control provides a versatile and experimentally validated framework for manipulating a broad class of non-Markovian open quantum systems of interest, with applications ranging from dynamical decoupling and dynamically corrected quantum gates, to noise spectroscopy and quantum simulation. In this context, transfer-function techniques directly motivated by control engineering have proved invaluable for obtaining a transparent picture of the controlled dynamics in the frequency domain and for quantitatively analyzing performance. In this talk, I will show how to identify a computationally tractable set of ``fundamental filter functions,'' out of which arbitrary filter functions may be assembled up to arbitrary high order in principle. Besides avoiding the infinite recursive hierarchy of filter functions that arises in general control scenarios, this fundamental set suffices to characterize the error suppression capabilities of the control protocol in both the time and frequency domain. I will show, in particular, how the resulting notion of ``filtering order'' reveals conceptually distinct, albeit complementary, features of the controlled dynamics as compared to the ``cancellation order,'' traditionally defined in the Magnus sense. Implications for current quantum control experiments will be discussed. Work supported by the U.S. Army Research Office under Contract No. W911NF-14-1-0682.

  14. Component Repair Experiment-1: An Experiment Evaluating Electronic Component-Level Repair During Spaceflight

    NASA Technical Reports Server (NTRS)

    Easton, John W.; Struk, Peter M.

    2012-01-01

    The Component Repair Experiment-1 (CRE-1) examines the capability for astronauts to perform electronics repair tasks in space. The goal is to determine the current capabilities and limits for the crew, and to make recommendations to improve and expand the range of work that astronauts may perform. CRE-1 provided two-layer, functional circuit boards and replacement components, a small tool kit, written and video training materials, and 1 hr of hands on training for the crew slated to perform the experiment approximately 7 months prior to the mission. Astronauts Michael Fincke and Sandra Magnus performed the work aboard the International Space Station (ISS) in February and March 2009. The astronauts were able to remove and replace components successfully, demonstrating the feasibility of performing component-level electronics repairs within a spacecraft. Several unsuccessful tasks demonstrated areas in need of improvement. These include improved and longer training prior to a mission, an improved soldering iron with a higher operating temperature and steady power source, video training and practice boards for refresher work or practice before a repair, and improved and varied hand tools and containment system.

  15. Calculating Floquet states of large quantum systems: A parallelization strategy and its cluster implementation

    NASA Astrophysics Data System (ADS)

    Laptyeva, T. V.; Kozinov, E. A.; Meyerov, I. B.; Ivanchenko, M. V.; Denisov, S. V.; Hänggi, P.

    2016-04-01

    We present a numerical approach to calculate non-equilibrium eigenstates of a periodically time-modulated quantum system. The approach is based on the use of a chain of single-step propagating operators. Each operator is time-specific and constructed by combining the Magnus expansion of the time-dependent system Hamiltonian with the Chebyshev expansion of an operator exponent. The construction of the unitary Floquet operator, which evolves a system state over the full modulation period, is performed by propagating the identity matrix over the period. The independence of the evolution of basis vectors makes the propagation stage suitable for realization on a parallel cluster. Once the propagation stage is completed, a routine diagonalization of the Floquet matrix is performed. Finally, an additional propagation round, now involving the eigenvectors as the initial states, allows to resolve the time-dependence of the Floquet states and calculate their characteristics. We demonstrate the accuracy and scalability of the algorithm by applying it to calculate the Floquet states of two quantum models, namely (i) a synthesized random-matrix Hamiltonian and (ii) a many-body Bose-Hubbard dimer, both of the size up to 104 states.

  16. Toledo School of Translators and their influence on anatomical terminology.

    PubMed

    Arráez-Aybar, Luis-Alfonso; Bueno-López, José-L; Raio, Nicolas

    2015-03-01

    Translation facilitates transmission of knowledge between cultures. The fundamental transfer of anatomic terminology from the Ancient Greek and Islamic Golden Age cultures, to medieval Latin Christendom took place in the so-called Toledo School of Translators in the 12th-13th centuries. Translations made in Toledo circulated widely across Europe. They were the foundation of scientific thinking that was born in the boards of first universities. In Toledo, Gerard of Cremona translated Avicenna's Canon of Medicine, the key work of Islamic Golden Age of medicine. Albertus Magnus, Mondino de Luzzi and Guy de Chauliac, the leading authors of anatomical Latin words in the Middle Ages, founded their books on Gerard's translations. The anatomical terms of the Canon retain auctoritas up to the Renaissance. Thus, terms coined by Gerard such as diaphragm, orbit, pupil or sagittal remain relevant in the current official anatomical terminology. The aim of the present paper is to bring new attention to the highly significant influence that the Toledo School of Translators had in anatomical terminology. For this, we shall review here the onomastic origins of a number of anatomical terms (additamentum; coracoid process; coxal; false ribs; femur; panniculus; spondylus; squamous sutures; thorax; xiphoid process, etc.) which are still used today. PMID:25667112

  17. Time-kill study of the activity of trovafloxacin compared with ciprofloxacin, sparfloxacin, metronidazole, cefoxitin, piperacillin and piperacillin/tazobactam against six anaerobes.

    PubMed

    Spangler, S K; Jacobs, M R; Appelbaum, P C

    1997-06-01

    A time-kill method was developed to examine the killing kinetics of trovafloxacin, ciprofloxacin, sparfloxacin, metronidazole, cefoxitin, piperacillin and piperacillin/tazobactam against one strain each of Bacteroides fragilis, Bacteroides thetaiotaomicron, Prevotella melaninogenica, Fusobacterium mortiferum, Peptostreptococcus magnus and Clostridium perfringens. Solutions and suspensions were prepared inside an anaerobic glove box, using syringes and prereduced broth. Bottles were then incubated outside the chamber and viability counts determined after incubation for 0, 6, 24 and 48 h in a shaking water bath, avoiding introduction of air. Bacteriostatic/bactericidal concentrations (mg/L) after 48 h for the six strains were: trovafloxacin, 0.03-1/0.03-1; ciprofloxacin, 0.25-16/0.25-32; sparfloxacin, 0.06-2/0.06-8; metronidazole 1-64/1-64; cefoxitin, 0.125-16/0.125-32; piperacillin, 0.125-64/0.125-64; piperacillin/tazobactam, 0.06-2/0.125-8. Bacteriostatic levels were within two dilutions of broth MICs. By this time-kill method, trovafloxacin had the lowest bacteriostatic concentrations of all compounds tested. PMID:9222066

  18. Effectiveness of Selected Fitness Exercises on Stress of Femoral Neck using Musculoskeletal Dynamics Simulations and Finite Element Model

    PubMed Central

    Qian, Jing-Guang; Li, Zhaoxia; Zhang, Hong; Bian, Rong; Zhang, Songning

    2014-01-01

    The purpose of the study was to establish a dynamics model and a three-dimensional (3D) finite element model to analyze loading characteristics of femoral neck during walking, squat, single-leg standing, and forward and lateral lunges. One male volunteer performed three trials of the five movements. The 3D kinematic data were captured and imported into the LifeMOD to establish a musculoskeletal dynamics model to obtain joint reaction and muscle forces of iliacus, gluteus medius, gluteus maximus, psoas major and adductor magnus. The loading data LfeMOD were imported and transformed into a hip finite-element model. The results of the finite element femur model showed that stress was localized along the compression arc and the tension arc. In addition, the trabecular bone and tension lines of the Ward’s triangle also demonstrated high stress. The compact bone received the greatest peak stress in the forward lunge and the least stress in the squat. However, the spongy bone in the femoral neck region had the greatest stress during the walk and the least stress in the squat. The results from this study indicate that the forward lunge may be an effective method to prevent femoral neck fractures. Walking is another effective and simple method that may improve bone mass of the Ward’s triangle and prevent osteoporosis and femoral neck fracture. PMID:25114732

  19. Medullary raphe midline is involved in production of expulsive expirations in anesthetized rabbits.

    PubMed

    Poliacek, I; Jakus, J; Knocikova, J; Barani, H; Halasova, E; Visnovcova, N

    2008-12-01

    Effects of kainic acid lesions in the medullary raphe midline on reflex expirations induced mechanically from the trachea were examined. Spontaneously breathing rabbits were anesthetized by ketamine and xylazine i.m., followed by pentobarbitone i.v. Excitatory neurotoxin kainic acid (2 mg/ml in artificial CSF, total volume of 55-100 nl) was pressure microinjected into the medullary midline, rostral to the obex (2 microinjections at 2 different depths). The lesion (mostly affected the obscurus and magnus raphe nuclei) reduced the number of reflex expirations by 80% and expiratory amplitudes of esophageal pressure, abdominal EMG moving averages, and abdominal EMG powers by 71%, 62%, and 57%, respectively (in all cases P<0.05). The duration of abdominal activity in post-lesion responses was not altered. Control microinjections of artificial CSF had no effect on the reflex responses. We conclude that in rabbits, the medullary raphe nuclei participate in the control of expiratory expulsions originating from the trachea. PMID:19218686

  20. [Nazi Terror against the Danish Medical Profession. The February 20, 1945 Murders in Odense].

    PubMed

    Jeune, Bernard; Hess, Søren; Skytthe, Axel; Stræde, Therkel

    2015-01-01

    On February 20, 1945, during the German occupation of Denmark, members of a notorious Nazi terror organization named the Petergroup murdered four young medical doctors at the city and regional hospital of Odense. On the 70th anniversary of the crime, a symposium was organized at the Odense University Hospital, and a monument revealed close to the site of the murders in commemoration of the four victims of the crime. The young physicians were not known to be connected with the Danish resistance, and they were shot without their murderers even knowing their identities in an attempt to revenge the growing resistance in Denmark's central, third largest city, and as a reprisal for several cases where the hospital had treated wounded resistance fighters, and prevented their being handed over to the German police. The article describes the terror action of February 20, 1945 and its perpetrators, as well as other Nazi attacks on members of the Danish medical profession. It lines out the strong protest voiced by the Danish central administration against the Odense hospital killings which were on the very same day seconded by further killings and a German campaign of blowing up important Odense buildings including two newspaper printing houses. Conclusively, the authors - by way of obituaries and material from relatives of the murdered - portray the four victims of the atrocity Christian Fabricius Møller, Jørgen Hvalkof, Henning Magnus Adelsteen Dalsgaard, and Henning Ørsberg. PMID:27086451

  1. Dispersal of non-sporeforming anaerobic bacteria from the skin.

    PubMed Central

    Benediktsdóttir, E.; Hambraeus, A.

    1982-01-01

    Dispersal of non-sporeforming anaerobic bacteria was studied. Skin samples were taken from the subjects, and dispersed from different parts of the body was examined. The number of anaerobic bacteria dispersed was not correlated to their density on the surface of skin area exposed. The highest density of anaerobic bacteria on the skin was found in the face and upper trunk, but the highest yield of anaerobic bacteria dispersed came from the lower trunk. The dominant anaerobic bacteria dispersed were Propionibacterium acnes, but Propionibacterium avidum, Propionibacterium granulosum and Gram-positive cocci were also isolated from the dispersal samples. Peptococcus magnus was the most common coccus isolated. For the less frequently isolated bacteria, the best correlation was found between the perineal flora and airborne bacteria. A comparison was also made of bacterial dispersal by naked and dressed subjects. The dispersal of both aerobic and anaerobic bacteria was higher when the subjects were dressed in conventional operating theatre cotton clothing than when they were naked. The increased dispersal of anaerobic bacteria when the subjects were dressed was mainly due to increased dispersal of Propionibacterium sp. PMID:6806353

  2. Instability of superfluid flow in the neutron star core

    NASA Astrophysics Data System (ADS)

    Link, B.

    2012-04-01

    Pinning of superfluid vortices to magnetic flux tubes in the outer core of a neutron star supports a velocity difference of ˜105 cm s-1 between the neutron superfluid and the proton-electron fluid as the star spins down. Under the Magnus force that arises on the vortex array, vortices undergo vortex creep through thermal activation or quantum tunnelling. We examine the hydrodynamic stability of this situation. Vortex creep introduces two low-frequency modes, one of which is unstable above a critical wavenumber for any non-zero flow velocity of the neutron superfluid with respect to the charged fluid. For typical pinning parameters of the outer core, the superfluid flow is unstable over wavelengths λ≲ 10 m and over time-scales of ˜(λ/1 m)1/2 yr down to ˜1 d. The vortex lattice could degenerate into a tangle, and the superfluid flow would become turbulent. We suggest that superfluid turbulence could be responsible for the red timing noise seen in many neutron stars, and find a predicted spectrum that is generally consistent with observations.

  3. Response of soil mites to organic cultivation in an ultisol in southeast Brazil.

    PubMed

    Badejo, M Adetola; De Aquino, Adriana Maria; De-Polli, Helvecio; Correia, Maria Elizabeth Fernandes

    2004-01-01

    Soil-dwelling mites of four plots under organic management were investigated in April and December 1998 and in December 1999. Their populations were compared with mite populations in a pasture and forest in the vicinity. It was observed that there was always an initial reduction in the populations of soil mites and in the activity of the epigeic forms whenever a plot was opened up and disturbed mechanically in preparation for cultivation, irrespective of previous organic inputs. With time, the densities and activities of mites recovered under organic management. The uropodine and oribatid mites in particular benefited more from organic management than gamasine and actinedid mites. Uropodine mites increased tremendously under banana where there was fresh cow dung manure. Oribatid mite species Nothrus seropedicalensis and Archegozetes magnus were dominant in organic plots where the soil was moist and temperatures were lower than the ambient. Protoribates rioensis was dominant in organic plots where the soil was drier and temperatures were higher than the ambient. Galumna was the most active oribatid taxon on the floor of all plots, with the highest activity recorded under maracuja and in pasture plots. The results suggest that while densities and activities of soil mites increased in the organic plots, the community structure and recruitment period of oribatid mites were altered. Oribatid mite diversity was higher in the organic plots than in the pasture but lower than in the forest, where Belba sp. and many Eremobelboid brachypiline genera were present, but absent in the organic plots and pasture. PMID:15651531

  4. STS-112 crew visits with Russian officials prior to launch

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- In the Operations and Checkout Building, the STS-112 crew takes time out from a visit with Russian officials to pose for a portrait. From left are Mission Specialist Fyodor N. Yurchikhin, Ph.D., a cosmonaut with the Russian Space Agency; Aslan Abashidze, President of the Autonomous Republic of Ajara in Georgia (Russia); Commander Jeffrey S. Ashby; Mission Specialist Sandra H. Magnus, Ph.D.; Pilot Pamela Ann Melroy; Georgi Abashidze, Mayor of Batumi (Yurchikhin's hometown); and Mission Specialist Piers J. Sellers, Ph.D. Mission Specialist David A. Wolf, M.D., not pictured, is also a member of the crew. The STS-112 crew is awaiting launch to the International Space Station aboard Space Shuttle Atlantis. The launch has been postponed to no earlier than Monday, Oct. 7, so that the Mission Control Center, located at the Lyndon B. Johnson Space Center in Houston, Texas, can be secured and protected from potential storm impacts from Hurricane Lili.

  5. [Skeletal muscle magnetic resonance imaging study in a patient with diabetic lumbosacral radiculoplexus neuropathy].

    PubMed

    Matsuda, Nozomu; Kobayashi, Shunsuke; Ugawa, Yoshikazu

    2014-01-01

    A 63-year-old man with type 2 diabetes mellitus developed deep aching and numbness in the right hip and lower extremity with rapid body weight loss. Neurological examination revealed weakness of the right hamstrings, tibialis anterior, and peroneus longus muscles with diminished ankle tendon reflex. We diagnosed him with diabetic lumbosacral radicuoloplexus neuropathy (DLRPN) based on neurological, radiological, and neurophysiological findings. Magnetic resonance imaging (MRI) of skeletal muscles showed high intensity signals on T2-weighted images in bilateral hamstrings, adductor magnus and right tensor fasciae latae, and lower leg extensor muscles. The MRI findings suggested muscle edema caused by acute denervation. DLRPN, or diabetic amyotrophy, is known to be caused by ischemic axonal degeneration. Our patient showed good functional recovery, and abnormal MRI signals in the involved muscles mostly disappeared in parallel to the clinical course. Distribution of the denervated muscles suggested that our patient had either patchy lesions in the lumbosacaral plexus or mononeuropathy multiplex in the nerve branches. The current study highlights the potential of skeletal muscle MRI for clinical evaluation of DLRPN. PMID:25283832

  6. The medieval origins of the concept of hypertension.

    PubMed

    Heydari, Mojtaba; Dalfardi, Behnam; Golzari, Samad E J; Habibi, Hamzeh; Zarshenas, Mohammad Mehdi

    2014-07-01

    Despite the well-known history of hypertension research in the modern era, like many other cardiovascular concepts, main points in the medieval concept of this disease and its early management methods remain obscure. This article attempts to make a brief review on the medieval origin of the concept of this disease from the Hidayat of Al-Akhawayni (?-983 AD). This article has reviewed the chapter of "Fi al-Imtela" (About the Fullness) from the Hidβyat al-Muta'allimin fi al-Tibb (The Students' Handbook of Medicine) of Al-Akhawayni. The definition, symptoms and treatments presented for the Imtela are compared with the current knowledge on hypertension. Akhawayni believed that Imtela could result from the excessive amount of blood within the blood vessels. It can manifest with symptoms including the presence of a pulsus magnus, sleepiness, weakness, dyspnea, facial blushing, engorgement of the vessels, thick urine, vascular rupture, and hemorrhagic stroke. He also suggested some ways to manage al-Imtela'. These include recommendations of changes in lifestyle (staying away from anger and sexual intercourse) and dietary program for patients (avoiding the consumption of wine, meat, and pastries, reducing the volume of food in a meal, maintaining a low-energy diet and the dietary usage of spinach and vinegar). Al-Akhawayni's description of "Imtela," despite of its numerous differences with current knowledge of hypertension, can be considered as medieval origin of the concept of hypertension. PMID:25538828

  7. Arthur Simons (1877-1942) and Tonic Neck Reflexes With Hemiplegic "Mitbewegungen" (Associated Reactions): Cinematography From 1916-1919.

    PubMed

    Holdorff, Bernd

    2016-01-01

    Tonic neck reflexes were investigated by Rudolf Magnus and Adriaan de Kleijn in animals and men in 1912 and eventually by Arthur Simons, a neurologist in Berlin and coworker of Hermann Oppenheim. Simons studied these reflexes in hemiplegic patients, who were mainly victims of World War I. This work became his most important contribution and remained unsurpassed for many years. The film (Filmarchiv, Bundesarchiv [Film Archive, National Archive] Berlin) with Simons as an examiner shows 11 war casualties with brain lesions that occurred between 1916 and 1919. The injuries reveal asymmetric neck reflexes with "Mitbewegungen," that is, flexion or extension on the hemiplegic side. Mitbewegungen is identical with Francis Walshe's "associated reactions" caused by neck rotation and/or by cocontraction of the nonaffected extremities, for example, by closing of the fist (Walshe). The knowledge of the neck reflexes is important in acute neurology and in rehabilitation therapy of hemiplegics for antispastic positions. Simons' investigations were conducted in the early era of increasing use of cinematography in medical studies. The film had been nearly forgotten until its rediscovery in 2010. PMID:26684424

  8. Photoballistics of volcanic jet activity at Stromboli, Italy

    NASA Technical Reports Server (NTRS)

    Chouet, B.; Hamisevicz, N.; Mcgetchin, T. R.

    1974-01-01

    Two night eruptions of the volcano Stromboli were studied through 70-mm photography. Single-camera techniques were used. Particle sphericity, constant velocity in the frame, and radial symmetry were assumed. Properties of the particulate phase found through analysis include: particle size, velocity, total number of particles ejected, angular dispersion and distribution in the jet, time variation of particle size and apparent velocity distribution, averaged volume flux, and kinetic energy carried by the condensed phase. The frequency distributions of particle size and apparent velocities are found to be approximately log normal. The properties of the gas phase were inferred from the fact that it was the transporting medium for the condensed phase. Gas velocity and time variation, volume flux of gas, dynamic pressure, mass erupted, and density were estimated. A CO2-H2O mixture is possible for the observed eruptions. The flow was subsonic. Velocity variations may be explained by an organ pipe resonance. Particle collimation may be produced by a Magnus effect.

  9. P-wave and S-wave traveltime residuals in Caledonian and adjacent units of Northern Europe and Greenland

    NASA Astrophysics Data System (ADS)

    Hejrani, Babak; Balling, Niels; Holm Jacobsen, Bo; Kind, Rainer; Tilmann, Frederik; England, Richard; Bom Nielsen, Søren

    2014-05-01

    This work combines P-wave and S-wave travel time residuals from in total 477 temporary and 56 permanent stations deployed across Caledonian and adjacent units in Northern Europe and Greenland (Tor, Gregersen et al. 2002; SVEKALAPKO, Sandoval et al., 2003; CALAS, Medhus et al, 2012a; MAGNUS, Weidle et al. 2010; SCANLIPS south, England & Ebbing 2012; SCANLIPS north, Hejrani et al. 2012; JULS Hejrani et al. 2013; plus permanent stations in the region). We picked data from 2002 to 2012 (1221 events) using a cross correlation technique on all waveforms recorded for each event. In this way we achieve maximum consistency of relative residuals over the whole region (Medhus et al. 2012b). On the European side 18362 P-wave travel time residuals was delivered. In East Greenland 1735 P-wave residuals were recovered at the Central Fjord array (13 stations) and 2294 residuals from the sparse GLISN-array (23 stations). Likewise, we picked a total of 6034 residuals of the SV phase (For the Tor and SVEKALAPKO projects we used data from Amaru et al. 2008). Relative residuals within the region are mainly due to sub-crustal uppermost mantle velocity anomalies. A dominant subvertical boundary was detected by Medhus et al. (2012), running along the Tornquist zone, east of the Oslo Graben and crossing under high topography of the southern Scandes. We delineated this boundary in more detail, tracking it towards the Atlantic margin north of Trondheim. Further north (Scanlips north), a similar subvertical upper mantle boundary seems to be present close to the coast, coinciding with the edge of the stretched crust. The North German Caledonides were probed by the new JULS (JUtland Lower Saxony) profile which closes the gap between Tor and CALAS arrays. Mantle structure found by the Tor project was confirmed, and modelling was extended to the eastern edge of the North Sea. References: Amaru, M. L., Spakman, W., Villaseñor, A., Sandoval, S., Kissling, E., 2008, A new absolute arrival time data

  10. Systematics of the parasitic wasp genus Oxyscelio Kieffer (Hymenoptera, Platygastridae s.l.), Part I: Indo-Malayan and Palearctic fauna

    PubMed Central

    Burks, Roger A.; Masner, Lubomír; Johnson, Norman F.; Austin, Andrew D.

    2013-01-01

    Abstract The Indo-Malayan and Palearctic species of Oxyscelio (Hymenoptera: Platygastridae s.l.) are revised. A total of 90 species are recognized as valid, 19 of which are redescribed - Oxyscelio acutiventris (Kieffer), Oxyscelio brevinervis (Kieffer), Oxyscelio carinatus (Kieffer), Oxyscelio ceylonensis (Dodd), Oxyscelio consobrinus (Kieffer), Oxyscelio crassicornis (Kieffer), Oxyscelio cupularis (Kieffer), Oxyscelio dorsalis (Kieffer), Oxyscelio excavatus (Kieffer), Oxyscelio flavipennis (Kieffer), Oxyscelio florus Kononova, Oxyscelio foveatus Kieffer, Oxyscelio kiefferi Dodd, Oxyscelio magnus (Kieffer), Oxyscelio marginalis (Kieffer), Oxyscelio naraws Kozlov & Lê, Oxyscelio perpensus Kononova, Oxyscelio rugosus (Kieffer) and Oxyscelio spinosiceps (Kieffer), and 71 which are described as new - Oxyscelio aclavae Burks, sp. n., Oxyscelio amrichae Burks, sp. n., Oxyscelio anguli Burks, sp. n., Oxyscelio angustifrons Burks, sp. n., Oxyscelio angustinubbin Burks, sp. n., Oxyscelio arcus Burks, sp. n., Oxyscelio arvi Burks, sp. n., Oxyscelio asperi Burks, sp. n., Oxyscelio aureamediocritas Burks, sp. n., Oxyscelio bipunctuum Burks, sp. n., Oxyscelio brevidentis Burks, sp. n., Oxyscelio caesitas Burks, sp. n., Oxyscelio capilli Burks, sp. n., Oxyscelio capitis Burks, sp. n., Oxyscelio cavinetrion Burks, sp. n., Oxyscelio chimaerae Burks, sp. n., Oxyscelio codae Burks, sp. n., Oxyscelio convergens Burks, sp. n., Oxyscelio cordis Burks, sp. n., Oxyscelio crateris Burks, sp. n., Oxyscelio crebritas Burks, sp. n., Oxyscelio crustum Burks, sp. n., Oxyscelio cuculli Burks, sp. n., Oxyscelio cyrtomesos Burks, sp. n., Oxyscelio dasymesos Burks, sp. n., Oxyscelio dasynoton Burks, sp. n., Oxyscelio dermatoglyphes Burks, sp. n., Oxyscelio doumao Burks, sp. n., Oxyscelio fistulae Burks, sp. n., Oxyscelio flabellae Burks, sp. n., Oxyscelio flaviventris Burks, sp. n., Oxyscelio fodiens Burks, sp. n., Oxyscelio fossarum Burks, sp. n., Oxyscelio fossularum Burks, sp. n., Oxyscelio

  11. SUPERFLUID VORTEX UNPINNING AS A COHERENT NOISE PROCESS, AND THE SCALE INVARIANCE OF PULSAR GLITCHES

    SciTech Connect

    Melatos, A.; Warszawski, L.

    2009-08-01

    The scale-invariant glitch statistics observed in individual pulsars (exponential waiting-time and power-law size distributions) are consistent with a critical self-organization process, wherein superfluid vortices pin metastably in macroscopic domains and unpin collectively via nearest-neighbor avalanches. Macroscopic inhomogeneity emerges naturally if pinning occurs at crustal faults. If, instead, pinning occurs at lattice sites and defects, which are macroscopically homogeneous, we show that an alternative, noncritical self-organization process operates, termed coherent noise, wherein the global Magnus force acts uniformly on vortices trapped in a range of pinning potentials and undergoing thermal creep. It is found that vortices again unpin collectively, but not via nearest-neighbor avalanches, and that, counterintuitively, the resulting glitch sizes are scale invariant, in accord with observational data. A mean-field analytic theory of the coherent noise process, supported by Monte Carlo simulations, yields a power-law size distribution, between the smallest and largest glitch, with exponent a in the range -2 {<=} a {<=} 0. When the theory is fitted to data from the nine most active pulsars, including the two quasi-periodic glitchers PSR J0537-6910 and PSR J0835-4510, it directly constrains the distribution of pinning potentials in the star, leading to two conclusions: (1) the potentials are broadly distributed, with the mean comparable to the standard deviation; and (2) the mean potential decreases with characteristic age. Fitting the theory to the data also constrains the pinned vortex fraction and the rate of thermal creep. An observational test is proposed to discriminate between nearest-neighbor avalanches and coherent noise: the latter process predicts a statistical excess of large glitches ('aftershocks') following a large glitch, whereas the former process does not. Its discriminatory power is discussed under various microphysical scenarios.

  12. A Comparative Evaluation of the Dimensional Stability of Three Different Elastomeric Impression Materials after Autoclaving – An Invitro Study

    PubMed Central

    Thota, Kiran Kumar; Ravuri, Rajyalakshmi; Tella, Suchita

    2014-01-01

    Aim of the Study: The purpose of the study was to determine the effect of autoclaving on the dimensional stability of three different elastomeric impression materials at three different time intervals. Materials and Methods: Standardized stainless steel master die as per ADA specification number 19 was fabricated. The impression materials used for the study were condensation silicone (GP1), addition silicone (GP2) and polyether (GP3). A total of 45 samples of the stainless steel die were made (n = 45), that is 15 samples for each group. Impression materials were mixed according to the manufacturer’s instructions and were loaded into the mold to make an impression of the die. Impressions were identified with the help of numerical coding system and measurements were made using stereomicroscope (MAGNUS MSZ-Bi) of 0.65x magnification with the help of image analysis software (IMACE PRO-INSIGHT VERSION.The results were subjected to statistical analysis using one way analysis of variance and student t-test for comparison between the groups. Results: Within the limitations of the study statistically significant dimensional changes were observed for all the three impression materials at three different time intervals but this change was not clinically significant. Conclusion: It is well-known fact that all impressions should be disinfected to avoid possible transmission of infectious diseases either by direct contact or cross contamination. Immersion and spray disinfection as well as various disinfection solutions have been tested and proven to be effective for this purpose. But for elastomeric impression materials these methods have proven to be ineffective as they do not prevent cross contamination among the dental team. So autoclaving was one of the most effective sterilization procedure for condensation silicone and addition silicone. Since polyether is hydrophilic it is better to disinfect the impressions as recommended by the manufacturer or by immersion or spray

  13. The identification and neurochemical characterization of central neurons that target parasympathetic preganglionic neurons involved in the regulation of choroidal blood flow in the rat eye using pseudorabies virus, immunolabeling and conventional pathway tracing methods.

    PubMed

    Li, Chunyan; Fitzgerald, Malinda E C; Del Mar, Nobel; Cuthbertson-Coates, Sherry; LeDoux, Mark S; Gong, Suzhen; Ryan, James P; Reiner, Anton

    2015-01-01

    The choroidal blood vessels of the eye provide the main vascular support to the outer retina. These blood vessels are under parasympathetic vasodilatory control via input from the pterygopalatine ganglion (PPG), which in turn receives its preganglionic input from the superior salivatory nucleus (SSN) of the hindbrain. The present study characterized the central neurons projecting to the SSN neurons innervating choroidal PPG neurons, using pathway tracing and immunolabeling. In the initial set of studies, minute injections of the Bartha strain of the retrograde transneuronal tracer pseudorabies virus (PRV) were made into choroid in rats in which the superior cervical ganglia had been excised (to prevent labeling of sympathetic circuitry). Diverse neuronal populations beyond the choroidal part of ipsilateral SSN showed transneuronal labeling, which notably included the parvocellular part of the paraventricular nucleus of the hypothalamus (PVN), the periaqueductal gray, the raphe magnus (RaM), the B3 region of the pons, A5, the nucleus of the solitary tract (NTS), the rostral ventrolateral medulla (RVLM), and the intermediate reticular nucleus of the medulla. The PRV+ neurons were located in the parts of these cell groups that are responsive to systemic blood pressure signals and involved in systemic blood pressure regulation by the sympathetic nervous system. In a second set of studies using PRV labeling, conventional pathway tracing, and immunolabeling, we found that PVN neurons projecting to SSN tended to be oxytocinergic and glutamatergic, RaM neurons projecting to SSN were serotonergic, and NTS neurons projecting to SSN were glutamatergic. Our results suggest that blood pressure and volume signals that drive sympathetic constriction of the systemic vasculature may also drive parasympathetic vasodilation of the choroidal vasculature, and may thereby contribute to choroidal baroregulation during low blood pressure. PMID:26082687

  14. Efficient time-symmetric simulation of torqued rigid bodies using Jacobi elliptic functions

    NASA Astrophysics Data System (ADS)

    Celledoni, E.; Säfström, N.

    2006-05-01

    If the three moments of inertia are distinct, the solution to the Euler equations for the free rigid body is given in terms of Jacobi elliptic functions. Using the arithmetic-geometric mean algorithm (Abramowitz and Stegun 1992 Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables (New York: Dover)), these functions can be calculated efficiently and accurately. Compared to standard numerical ODE and Lie-Poisson solvers, the overall approach yields a faster and more accurate numerical solution to the Euler equations. This approach is designed for mass asymmetric rigid bodies. In the case of symmetric bodies, the exact solution is available in terms of trigonometric functions, see Dullweber et al (1997 J. Chem. Phys. 107 5840-51), Reich (1996 Fields Inst. Commun. 10 181-91) and Benettin et al (2001 SIAM J. Sci. Comp. 23 1189-203) for details. In this paper, we consider the case of asymmetric rigid bodies subject to external forces. We consider a strategy similar to the symplectic splitting method proposed in Reich (1996 Fields Inst. Commun. 10 181-91) and Dullweber et al (1997 J. Chem. Phys. 107 5840-51). The method proposed here is time-symmetric. We decompose the vector field of our problem into a free rigid body (FRB) problem and another completely integrable vector field. The FRB problem consists of the Euler equations and a differential equation for the 3 × 3 orientation matrix. The Euler equations are integrated exactly while the matrix equation is approximated using a truncated Magnus series. In our experiments, we observe that the overall numerical solution benefits greatly from the very accurate solution of the Euler equations. We apply the method to the heavy top and the simulation of artificial satellite attitude dynamics.

  15. Molecular identity and prevalence of Cryptococcus spp. nasal carriage in asymptomatic feral cats in Italy.

    PubMed

    Danesi, Patrizia; Furnari, Carmelo; Granato, Anna; Schivo, Alice; Otranto, Domenico; Capelli, Gioia; Cafarchia, Claudia

    2014-10-01

    Cryptococcosis is a life-threatening fungal disease that infects humans and animals worldwide. Inhalation of fungal particles from an environmental source can cause primary infection of the respiratory system. As animals can be considered a sentinel for human diseases, the aim of this study was to determine the prevalence and molecular identity of Cryptococcus spp. in the nasal cavity of feral cats. Cats from 162 urban and rural feral cat colonies were sampled over 3 years. Of 766 cats from which nasal swabs were obtained, Cryptococcus spp. were recovered from 95 (12.6%), including 37 C. magnus (4.8%), 16 C. albidus (2.0%), 15 C. carnescens (1.9%), 12 C. neoformans (1.6%), as well as C. oeirensis (n = 3), C. victoriae (n = 3), C. albidosimilis (n = 2), Filobasidium globisporum (n = 2), C. adeliensis (n = 1), C. flavescens (n = 1), C. dimnae (n = 1), C. saitoi (n = 1), and C. wieringae (n = 1) with prevalence <1%. Thirteen Cryptococcus species were identified by polymerase chain reaction and sequencing of internal transcribed spacer amplicons. Statistical analysis did not identify any predisposing factors that contributed to nasal colonization (eg, sex, age, season, or habitat). Results suggest that asymptomatic feral cats may carry C. neoformans and other Cryptococcus species in their sinonasal cavity. Genotyping of the specific cryptococcal isolates provides a better understanding of the epidemiology of these yeasts. PMID:25082953

  16. β-Hydroxy-β-methylbutyrate attenuates cytokine response during sustained military training.

    PubMed

    Hoffman, Jay R; Gepner, Yiftach; Stout, Jeffrey R; Hoffman, Mattan W; Ben-Dov, Daniel; Funk, Shany; Daimont, Ido; Jajtner, Adam R; Townsend, Jeremy R; Church, David D; Shelef, Ilan; Rosen, Philip; Avital, Guy; Chen, Yacov; Frankel, Hagai; Ostfeld, Ishay

    2016-06-01

    This study tested the hypothesis that of 23 days of β-hydroxy-β-methylbutyrate (HMB) supplementation can maintain muscle mass and attenuate the immune and inflammatory response in combat soldiers during highly intense military training. Soldiers were randomly assigned to either a HMB (n = 6) or placebo (PL; n = 7) group and provided with 3 g · day(-1) of either HMB or PL. During the final week of supplementation soldiers participated in extreme physical training, which included night navigation of 6-8 hours across difficult terrain carrying heavy loads combined with sleep deprivation (3.8 ± 3.0 h per night). Blood draws were performed prior to and following the supplementation period. Magnetic resonance imaging, which included diffusion tensor imaging sequence, was used for muscle fiber tracking analysis. Data was analyzed using a two-way mixed factorial analysis of variance. Magnitude-based inferences were used to provide inferences on the true effects that HMB may have had on the dependent variables compared to PL, calculated from 90% confidence intervals. Changes in tumor necrosis factor-α for HMB (-3.9 ± 8.2 pg · mL(-1)) were significantly lower (P = .043) compared to the change in PL (+4.0 ± 3.7 pg · mL(-1)). HMB ingestion was also very likely (92%-95% Likelihood) to lower granulocyte colony-stimulating factor and interleukin 10 compared to PL. In addition, HMB supplementation was likely (78%-87% likelihood) to reduce interferon-γ, interleukin 8, CX3CL1, and increase muscle volume for the adductor magnus (77% likelihood) compared to PL. In summary, the results of this study provides evidence that HMB supplementation may attenuate the inflammatory response to high intense military training, and maintain muscle quality. PMID:27188901

  17. [Alpha1-adrenoceptor subtype selectivity and organ specificity of silodosin (KMD-3213)].

    PubMed

    Tatemichi, Satoshi; Kobayashi, Kumi; Maezawa, Ayaka; Kobayashi, Mamoru; Yamazaki, Yoshinobu; Shibata, Nobuo

    2006-03-01

    The selectivity of silodosin (KMD-3213), an antagonist of alpha(1)-adrenoceptor (AR), to the subtypes (alpha(1A)-, alpha(1B)- and alpha(1D)-ARs) was examined by a receptor-binding study and a functional pharmacological study, and we compared its subtype-selectivity with those of other alpha(1)-AR antagonists. In the receptor-binding study, a replacement experiment using [(3)H]-prazosin was conducted using the membrane fraction of mouse-derived LM (tk-) cells in which each of three human alpha(1)-AR subtypes was expressed. In the functional pharmacological study, the following isolated tissues were used as representative organs with high distribution densities of alpha(1)-AR subtypes (alpha(1A)-AR: rabbit prostate, urethra and bladder trigone; alpha(1B)-AR: rat spleen; alpha(1D)-AR: rat thoracic aorta). Using the Magnus method, we studied the inhibitory effect of silodosin on noradrenaline-induced contraction, and compared it with those of tamsulosin hydrochloride, naftopidil and prazosin hydrochloride. Silodosin showed higher selectivity for the alpha(1A)-AR subtype than tamsulosin hydrochloride, naftopidil or prazosin hydrochloride (affinity was highest for tamsulosin hydrochloride, followed by silodosin, prazosin hydrochloride and naftopidil in that order). Silodosin strongly antagonized noradrenaline-induced contractions in rabbit lower urinary tract tissues (including prostate, urethra and bladder trigone, with pA(2) or pKb values of 9.60, 8.71 and 9.35, respectively). On the other hand, the pA(2) values for antagonism of noradrenaline-induced contractions in rat isolated spleen and rat isolated thoracic aorta were 7.15 and 7.88, respectively. Selectivity for lower urinary tract was higher for silodosin than for the other alpha(1)-AR antagonists. Our data suggest that silodosin has a high selectivity for the alpha(1A)-AR subtype and for the lower urinary tract. PMID:16518085

  18. Possible Loss of GABAergic Inhibition in Mice With Induced Adenomyosis and Treatment With Epigallocatechin-3-Gallate Attenuates the Loss With Improved Hyperalgesia

    PubMed Central

    Chen, Yumei; Zhu, Bo; Zhang, Hongping; Ding, Ding; Liu, Xishi

    2014-01-01

    We have previously reported that induction of adenomyosis in mice results in progressive hyperalgesia, uterine hyperactivity, and elevated plasma corticosterone levels and that epigallocatechin-3-gallate (EGCG) treatment dose dependently suppressed myometrial infiltration and improved generalized hyperalgesia. In this study, we examined whether adenomyosis induced in mice results in the loss of GABAergic inhibition as manifested by the diminished glutamate decarboxylase (GAD) 65-expressing neurons in the brainstem nucleus raphe magnus (NRM) that could correlate with heightened hyperalgesia. We also evaluated whether EGCG treatment would reverse these changes and also improve the expression of some proteins known to be involved in adenomyosis. Adenomyosis was induced in 28 female ICR mice and additional 12 were used as blank controls, as reported previously. At the 16th week, all mice with induced adenomyosis received low- or high-dose EGCG treatment or untreated. Mice without adenomyosis received no treatment. After 3 weeks of treatment, their uterine horns and brains were harvested. The right uterine horn was used for immunohistochemistry analysis and for counting the number of macrophages infiltrating into the ectopic endometrium. The brainstem NRM sections were subjected to immunofluorescence staining for GAD65. We found that mice with induced adenomyosis had significantly diminished GAD65-expressing neurons, concomitant with heightened hyperalgesia. Treatment with EGCG increased these neurons in conjunction with improved hyperalgesia, reduced the expression of p-p65, cycloxygenase 2, oxytocin receptor, collagen I and IV, and transient receptor potential vanilloid type 1 in ectopic endometrium or myometrium, reduced the number of macrophages infiltrating into the ectopic endometrium while elevated the expression of progesterone receptor isoform B. Thus, adenomyosis-induced pain resembles neuropathic pain in that there is a remarkable central plasticity. PMID

  19. Monitoring creatine and phosphocreatine by (13)C MR spectroscopic imaging during and after (13)C4 creatine loading: a feasibility study.

    PubMed

    Janssen, Barbara H; Lassche, Saskia; Hopman, Maria T; Wevers, Ron A; van Engelen, Baziel G M; Heerschap, Arend

    2016-08-01

    Creatine (Cr) supplementation to enhance muscle performance shows variable responses among individuals and different muscles. Direct monitoring of the supplied Cr in muscles would address these differences. In this feasibility study, we introduce in vivo 3D (13)C MR spectroscopic imaging (MRSI) of the leg with oral ingestion of (13)C4-creatine to observe simultaneously Cr and phosphocreatine (PCr) for assessing Cr uptake, turnover, and the ratio PCr over total Cr (TCr) in individual muscles. (13)C MRSI was performed of five muscles in the posterior thigh in seven subjects (two males and two females of ~20 years, one 82-year-old male, and two neuromuscular patients) with a (1)H/(13)C coil in a 3T MR system before, during and after intake of 15 % (13)C4-enriched Cr. Subjects ingested 20 g Cr/day for 4 days in four 5 g doses at equal time intervals. The PCr/TCr did not vary significantly during supplementation and was similar for all subjects and investigated muscles (average 0.71 ± 0.07), except for the adductor magnus (0.64 ± 0.03). The average Cr turnover rate, assessed in male muscles, was 2.1 ± 0.7 %/day. The linear uptake rates of Cr were variable between muscles, although not significantly different. This assessment was possible in all investigated muscles of young male volunteers, but less so in muscles of the other subjects due to lower signal-to-noise ratio. Improvements for future studies are discussed. In vivo (13)C MRSI after (13)C-Cr ingestion is demonstrated for longitudinal studies of Cr uptake, turnover, and PCr/TCr ratios of individual muscles in one exam. PMID:27401085

  20. Fast and accurate approximate inference of transcript expression from RNA-seq data

    PubMed Central

    Hensman, James; Papastamoulis, Panagiotis; Glaus, Peter; Honkela, Antti; Rattray, Magnus

    2015-01-01

    Motivation: Assigning RNA-seq reads to their transcript of origin is a fundamental task in transcript expression estimation. Where ambiguities in assignments exist due to transcripts sharing sequence, e.g. alternative isoforms or alleles, the problem can be solved through probabilistic inference. Bayesian methods have been shown to provide accurate transcript abundance estimates compared with competing methods. However, exact Bayesian inference is intractable and approximate methods such as Markov chain Monte Carlo and Variational Bayes (VB) are typically used. While providing a high degree of accuracy and modelling flexibility, standard implementations can be prohibitively slow for large datasets and complex transcriptome annotations. Results: We propose a novel approximate inference scheme based on VB and apply it to an existing model of transcript expression inference from RNA-seq data. Recent advances in VB algorithmics are used to improve the convergence of the algorithm beyond the standard Variational Bayes Expectation Maximization algorithm. We apply our algorithm to simulated and biological datasets, demonstrating a significant increase in speed with only very small loss in accuracy of expression level estimation. We carry out a comparative study against seven popular alternative methods and demonstrate that our new algorithm provides excellent accuracy and inter-replicate consistency while remaining competitive in computation time. Availability and implementation: The methods were implemented in R and C++, and are available as part of the BitSeq project at github.com/BitSeq. The method is also available through the BitSeq Bioconductor package. The source code to reproduce all simulation results can be accessed via github.com/BitSeq/BitSeqVB_benchmarking. Contact: james.hensman@sheffield.ac.uk or panagiotis.papastamoulis@manchester.ac.uk or Magnus.Rattray@manchester.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online

  1. Muscle imaging data in late-onset Pompe disease reveal a correlation between the pre-existing degree of lipomatous muscle alterations and the efficacy of long-term enzyme replacement therapy

    PubMed Central

    Gruhn, Kai Michael; Heyer, Christoph Malte; Güttsches, Anne-Katrin; Rehmann, Robert; Nicolas, Volkmar; Schmidt-Wilcke, Tobias; Tegenthoff, Martin; Vorgerd, Matthias; Kley, Rudolf Andre

    2015-01-01

    Background Late-onset Pompe disease (LOPD) is a metabolic myopathy caused by mutations in GAA and characterized by proximal muscle weakness and respiratory insufficiency. There is evidence from clinical studies that enzyme replacement therapy (ERT) with human recombinant alpha-glucosidase improves motor performance and respiratory function in LOPD. Objective We analyzed quantitative muscle MRI data of lower limbs to evaluate the effects of long-term ERT on muscle parameters. Methods Three symptomatic LOPD patients who received ERT for five years and four untreated presymptomatic LOPD patients were included in the study. T1-weighted MRI images were used to determine volumes of thigh and lower leg muscles. In addition, mean gray values of eight individual thigh muscles were calculated to assess the degree of lipomatous muscle alterations. Results We detected a decrease in thigh muscle volume of 6.7% (p < 0.001) and an increase in lower leg muscle volume of 8.2% (p = 0.049) after five years of ERT. Analysis of individual thigh muscles revealed a positive correlation between the degree of lipomatous muscle alterations at baseline and the increase of gray values after five years of ERT (R2 = 0.68, p < 0.001). Muscle imaging in presymptomatic patients showed in one case pronounced lipomatous alteration of the adductor magnus muscle and mild to moderate changes in further thigh muscles. Conclusions The results demonstrate that fatty muscle degeneration can occur before clinical manifestation of muscle weakness and suggest that mildly affected muscles may respond better to ERT treatment than severely involved muscles. If these findings can be validated by further studies, it should be discussed if muscle alterations detected by muscle MRI may be an objective sign of disease manifestation justifying an early start of ERT in clinically asymptomatic patients in order to improve the long-term outcome. PMID:26937398

  2. Unravelling the Biodiversity and Molecular Phylogeny of Needle Nematodes of the Genus Longidorus (Nematoda: Longidoridae) in Olive and a Description of Six New Species

    PubMed Central

    Archidona-Yuste, Antonio; Navas-Cortés, Juan A.; Cantalapiedra-Navarrete, Carolina; Palomares-Rius, Juan E.; Castillo, Pablo

    2016-01-01

    The genus Longidorus includes a remarkable group of invertebrate animals of the phylum Nematoda comprising polyphagous root-ectoparasites of numerous plants including several agricultural crops and trees. Damage is caused by direct feeding on root cells as well as by transmitting nepoviruses that cause disease on those crops. Thus, correct identification of Longidorus species is essential to establish appropriate control measures. We provide the first detailed information on the diversity and distribution of Longidorus species infesting wild and cultivated olive soils in a wide-region in southern Spain that included 159 locations from which 449 sampling sites were analyzed. The present study doubles the known biodiversity of Longidorus species identified in olives by including six new species (Longidorus indalus sp. nov., Longidorus macrodorus sp. nov., Longidorus onubensis sp. nov., Longidorus silvestris sp. nov., Longidorus vallensis sp. nov., and Longidorus wicuolea sp. nov.), two new records for wild and cultivate olives (L. alvegus and L. vineacola), and two additional new records for wild olive (L. intermedius and L. lusitanicus). We also found evidence of some geographic species associations to western (viz. L. alvegus, L. intermedius, L. lusitanicus, L. onubensis sp. nov., L. vineacola, L. vinearum, L. wicuolea sp. nov.) and eastern distributions (viz. L. indalus sp. nov.), while only L. magnus was detected in both areas. We developed a comparative study by considering morphological and morphometrical features together with molecular data from nuclear ribosomal RNA genes (D2–D3 expansion segments of 28S, ITS1, and partial 18S). Results of molecular and phylogenetic analyses confirmed the morphological hypotheses and allowed the delimitation and discrimination of six new species of the genus described herein and four known species. Phylogenetic analyses of Longidorus spp. based on three molecular markers resulted in a general consensus of these species

  3. Organization of projections from the raphe nuclei to the vestibular nuclei in rats

    NASA Technical Reports Server (NTRS)

    Halberstadt, A. L.; Balaban, C. D.

    2003-01-01

    Previous anatomic and electrophysiological evidence suggests that serotonin modulates processing in the vestibular nuclei. This study examined the organization of projections from serotonergic raphe nuclei to the vestibular nuclei in rats. The distribution of serotonergic axons in the vestibular nuclei was visualized immunohistochemically in rat brain slices using antisera directed against the serotonin transporter. The density of serotonin transporter-immunopositive fibers is greatest in the superior vestibular nucleus and the medial vestibular nucleus, especially along the border of the fourth ventricle; it declines in more lateral and caudal regions of the vestibular nuclear complex. After unilateral iontophoretic injections of Fluoro-Gold into the vestibular nuclei, retrogradely labeled neurons were found in the dorsal raphe nucleus (including the dorsomedial, ventromedial and lateral subdivisions) and nucleus raphe obscurus, and to a minor extent in nucleus raphe pallidus and nucleus raphe magnus. The combination of retrograde tracing with serotonin immunohistofluorescence in additional experiments revealed that the vestibular nuclei receive both serotonergic and non-serotonergic projections from raphe nuclei. Tracer injections in densely innervated regions (especially the medial and superior vestibular nuclei) were associated with the largest numbers of Fluoro-Gold-labeled cells. Differences were observed in the termination patterns of projections from the individual raphe nuclei. Thus, the dorsal raphe nucleus sends projections that terminate predominantly in the rostral and medial aspects of the vestibular nuclear complex, while nucleus raphe obscurus projects relatively uniformly throughout the vestibular nuclei. Based on the topographical organization of raphe input to the vestibular nuclei, it appears that dense projections from raphe nuclei are colocalized with terminal fields of flocculo-nodular lobe and uvula Purkinje cells. It is hypothesized that

  4. Marcella O'Grady Boveri (1865-1950) and the chromosome theory of cancer.

    PubMed Central

    McKusick, V A

    1985-01-01

    Born into a Boston Irish family, Marcella Imelda O'Grady was the first woman graduate in biology from MIT (1885) where she came under the influence of two recent PhD graduates of Johns Hopkins University, William Townsend Sedgwick and Edmund Beecher Wilson. She taught science at Bryn Mawr School for girls in Baltimore 1885 to 1887 and was teaching assistant with E B Wilson at Bryn Mawr College for women in Bryn Mawr, Pennsylvania, 1887 to 1889. From 1889 to 1896 she headed the Department of Biology at Vassar College for women in Poughkeepsie, New York. On the recommendation of E B Wilson (who from the first edition in 1896 dedicated his famous book The cell in development and inheritance to Boveri) Marcella went to Würzburg to spend a sabbatical with Boveri. One year later she married Boveri and during the next 18 years until Boveri's untimely death in 1915 she was her husband's close scientific collaborator, especially in his work at the marine zoological stations in Naples and Villefranche, France. She also acquired (from Freiburg) the doctorate she had unsuccessfully attempted to get at Johns Hopkins. Marcella returned to the United States in 1926 and headed the Biology Department at Albertus Magnus College in New Haven. She was there in 1929 when her English translation of her husband's 1914 monograph advancing the chromosome theory of cancer was published. The translation did much to bring that theory to the attention of a wider audience which has thereby been able to rediscover Boveri, despite lack of a reading knowledge of German. Boveri's theory was based on the views that cancer is a cellular problem, cancers originate from a single cell, this cell has an abnormality of its chromosomal constitution, and the chromosomal abnormality which is passed on to all the descendants of the cell of origin is the cause of rapid cell proliferation. Images PMID:3908684

  5. Effect of electroacupuncture pretreatment at GB20 on behaviour and the descending pain modulatory system in a rat model of migraine

    PubMed Central

    Pei, Pei; Liu, Lu; Zhao, Luopeng; Cui, Yingxue; Qu, Zhengyang; Wang, Linpeng

    2016-01-01

    Background While electroacupuncture (EA) pretreatment has been found to ameliorate migraine-like symptoms, the underlying mechanisms remain poorly understood. Emerging evidence suggests that the brainstem descending pain modulatory system, comprising the periaqueductal grey (PAG), raphe magnus nucleus (RMg), and trigeminal nucleus caudalis (TNC), may be involved in migraine pathophysiology. We hypothesised that EA would ameliorate migraine-like symptoms via modulation of this descending system. Methods We used a conscious rat model of migraine induced by repeated electrical stimulation of the dura. Forty male Sprague-Dawley rats were randomly assigned to one of four groups: an EA group, which received EA at GB20 following dural stimulation; a sham acupuncture (SA) group, which received manual acupuncture at a non-acupuncture point following dural stimulation; a Model group, which received dural stimulation but no acupuncture; and a Control group, which received neither dural stimulation nor acupuncture (electrode implantation only). HomeCageScan was used to measure effects on behaviour, and immunofluorescence staining was used to examine neural activation (c-Fos immunoreactivity) in the PAG, RMg, and TNC. Results Compared to the Model group, rats in the EA group showed a significant increase in exploratory, locomotor and eating/drinking behaviour (p<0.01) and a significant decrease in freezing-like resting and grooming behaviour (p<0.05). There was a significant increase in the mean number of c-Fos neurons in the PAG, RMg, and TNC in Model versus Control groups (p<0.001); however, this was significantly attenuated by EA treatment (p<0.001). There were no significant differences between the SA and Model groups in behaviour or c-Fos immunoreactivity. Conclusions EA pretreatment ameliorates behavioural changes in a rat model of recurrent migraine, possibly via modulation of the brainstem descending pathways. PMID:26438555

  6. Asteroid Phase Curves: Two- And Three-parameter Fits

    NASA Astrophysics Data System (ADS)

    Oszkiewicz, Dagmara; Muinonen, K.; Bowell, E.; Trilling, D.

    2010-10-01

    We apply the two-parameter H, G12 and the three-parameter H, G1, G2 magnitude phase functions (Muinonen et al., Icarus, in press) to photometric data from the Minor Planet Center, as modified in observational data files at Lowell Observatory, to derive improved absolute magnitudes (H) and slope parameters for individual asteroids (G12) and for groups of asteroids: e.g., main-belt zones, families (G1, G2). The Lowell Observatory orbital data file comprises about 535,000 records. Most of the photometric data are of low precision (generally rounded to 0.1 mag) and low accuracy (rms magnitude uncertainties of ± 0.5 mag are typical). To offset the low accuracy, the photometric data are very numerous: about 73,000,000 individual, largely independent magnitude estimates exist. Here we present our preliminary estimates of absolute magnitudes using the H, G1, G2 magnitude phase functions and compare them with the values derived using the H, G12 two-parameter phase functions. A java applet version of the fitting procedures will soon be available on the web. In future, we plan to combine the derived absolute magnitudes with thermal data from the "Spitzer Asteroid Catalog". The Spitzer catalog includes observations of several hundred near-Earth asteroids and about 100,000 main-belt asteroids most of them observed at 24 micrometer wavelength. The catalog contains fluxes, derived albedos, and diameters. By far the biggest source of error in the catalog stems from inaccurate visible magnitudes. Improved asteroid absolute magnitudes will also lead to better visible magnitude prediction and hence better calibrated asteroid albedos derived from thermal-models. Further, we plan to explore correlations among taxa, color indices, albedos, and phase curves. A significant data product will be a frequently updated list of asteroid photometric parameters and their uncertainties. Research supported, by Magnus Ehrnrooth Foundation, Spitzer Science Center and Lowell Observatory.

  7. The S1 Truss Prior to Installation on the International Space Station

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Being attached to the Canadarm2 on the International Space Station (ISS), the Remote Manipulator System arm built by the Canadian Space Agency, the Integrated Truss Assembly (S1) Truss is suspended over the Space Shuttle Orbiter Atlantis' cargo bay. Astronauts Sandra H. Magnus, STS-112 mission specialist, and Peggy A. Whitson, Expedition Five flight engineer, used the Canadarm2 from inside the Destiny laboratory on the ISS to lift the S1 truss out of the orbiter's cargo bay and move it into position prior to its installation on the ISS. The primary payloads of this mission, ISS Assembly Mission 9A, were the Integrated Truss Assembly S1 (S One), the starboard side thermal radiator truss, and the Crew Equipment Translation Aid (CETA) cart to the ISS. The S1 truss provides structural support for the orbiting research facility's radiator panels, which use ammonia to cool the Station's complex power system. The S1 truss was attached to the S0 (S Zero) truss, which was launched on April 8, 2002 aboard the STS-110, and flows 637 pounds of anhydrous ammonia through three heat-rejection radiators. The truss is 45-feet long, 15-feet wide, 10-feet tall, and weighs approximately 32,000 pounds. The CETA cart was attached to the Mobil Transporter and will be used by assembly crews on later missions. Manufactured by the Boeing Company in Huntington Beach, California, the truss primary structure was transferred to the Marshall Space Flight Center in February 1999 for hardware installations and manufacturing acceptance testing. The launch of the STS-112 mission occurred on October 7, 2002, and its 11-day mission ended on October 18, 2002.

  8. [A complex study of the movement biomechanics in patients with post-stroke hemiparesis].

    PubMed

    Skvortsov, D V; Bulatova, M A; Kovrazhkina, E A; Suvorov, A Iu; Ivanova, G E; Skvortsova, V I

    2012-01-01

    The authors present results of a pilot study on biomechanics of non-cyclic movements of the human consequent verticalization in the ontogenesis of patients with post-stroke hemiparesis (10 patients in the acute stage of cerebral stroke) and 10 healthy volunteers without neurologic and orthopedic pathology. Some movements of therapeutic exercises Balance (a model of ontogenetic kinesitherapy) have been selected for the study. Cinematic parameters have been recorded using a system of motion 3D video analysis, a kinematic model was build in accordance to standard protocols. The skin (native and straightened) electromyogram (EMG) was recorded synchronously with kinematic data using 16-channel electromyography from the following pairs of muscles: mm. sternocleido-mastoideus, trapezius (горизонтальная порция), biceps brachii, triceps brachii, rectus femoris, adductor magnus. Major differences in the EMG picture between patients and controls were: 1) the EMG "monotony" with the involvement of multiple additional muscles in locomotions with the prevalence of the peculiar "tonic" muscle activity (low amplitudes without distinct peaks), stretching along the whole cycle of movement. In controls, EMG demonstrated variability and had mostly "phasic" character with distinct 1 or 2 peaks; 2) the asymmetry of EMG profile in symmetric movements. i.e. when performed simultaneously from the right and from the left sides. The latter feature may be considered as predictive because it was never found in healthy people. It allows to identify objectively weak muscles even in the absence of visible parethis during the routine neurological examination. PMID:22983241

  9. Electroacupuncture suppresses hyperalgesia and spinal Fos expression by activating the descending inhibitory system

    PubMed Central

    Li, Aihui; Wang, Yi; Xin, Giagia; Lao, Lixing; Ren, Ke; Berman, Brian M.; Zhang, Rui-Xin

    2008-01-01

    Although electroacupuncture (EA) is widely used to treat pain, its mechanisms have not been completely understood. The present study investigated the descending inhibitory system involvement in EA action. Inflammatory pain was induced by injecting complete Freund’s adjuvant subcutaneously into one hind paw of rats with dorsolateral funiculus lesions and sham-operated rats. EA treatment, 10 Hz at 3 mA, was given twice for 20 min each, once immediately post- and again 2 h post-Freund’s adjuvant at GB 30, at the junction of the lateral 1/3 and medial 2/3 of the distance between the greater trochanter and sacral hiatus. For sham EA control, acupuncture needles were inserted bilaterally into GB 30 without electrical or manual stimulation. Paw withdrawal latency to a noxious thermal stimulus was measured at baseline and 20 min after EA treatment. Compared to sham EA, EA significantly (P<0.05, n=9) increased withdrawal latency of the inflamed hind paws in the sham-operated rats but not in those with dorsolateral funiculus lesions, indicating that lesioning blocked EA-produced anti-hyperalgesia. EA, compared to sham EA, also significantly inhibited Fos expression in laminae I-II of the spinal cord in the sham-operated rats (58.4 ± 6.5 vs 35.2 ± 5.4 per section) but not in those with dorsolateral funiculus lesions. Further, EA activated serotonin- and catecholamine-containing neurons in the nucleus raphe magnus and locus coeruleus that project to the spinal cord. The results demonstrate that EA inhibits transmission of noxious messages and hyperalgesia by activating supraspinal neurons that project to the spinal cord. PMID:18001697

  10. An anomalous upper mantle unit beneath southern Norway revealed by P-wave travel time residuals.

    NASA Astrophysics Data System (ADS)

    Bondo, A.; Balling, N.; Jacobsen, B. H.; England, R. W.; Kind, R.; Bödvarsson, R.; Weidle, C.; Gregersen, S.; Voss, P.

    2009-04-01

    We investigate whether high topography in southern Norway is associated with an anomalous upper mantle and we identify the western boundary of thick shield lithosphere. Several studies describe crustal structure in southern Scandinavia, whereas high-resolution information on upper mantle structures is sparse. We present relative P-wave travel time residuals (P-residuals) and preliminary tomography from southern Norway, southern Sweden and northern Denmark. We analyze distant earthquakes registered by seismological stations in projects CENMOVE, CALAS, MAGNUS and SCANLIPS together with selected TOR stations, and permanent stations in southern Sweden, southern Norway and Denmark. Station means of P-residuals corrected for topography and contributions from the crust varies by up to about 1 s across the study area. We associate early arrivals to the east of the Sorgenfrei-Tornquist Zone (STZ) and east of the Oslo Graben with thick shield lithosphere. Late arrivals observed in the Norwegian-Danish Basin southwest of the STZ are consistent with thinned lithosphere related to the basin formation. In southern Norway west of the Oslo Graben area, late arrivals indicate reduced P-wave velocity in the upper mantle and perhaps some regional isostatic buoyancy from the upper mantle. However, arrivals are early in the northern part of southern Norway, still in areas of high topography. Thus, a clear spatial correlation with areas of high topography is not observed. We identify the western boundary of thick shield lithosphere by interpretation of station means of P-residuals, together with the azimuthal dependence of single P-residuals in southern Scandinavia. We find this boundary to follow the STZ from the southeast into the northern part of Jutland. From there it proceed northwards. In southern Norway the western boundary of thick shield lithosphere is found around the Oslo Graben, proceeding to the northwest approaching the Norwegian coast.

  11. Man against volcano: The eruption on Heimaey, Vestmann Islands, Iceland

    USGS Publications Warehouse

    Williams, R.S., Jr.; Moore, J.G.

    1976-01-01

    The U.S. Geological Survey carries out scientific studies in the geological, hydrological, and cartographic sciences generally within the 50 states, but also in cooperation with scientific organizations in many foreign countries for the investigation of unusual earth science phenomena throughout the world. The following material discusses the impact of the 1973 volcanic eruption of Eldfell on the fishing port of Vestmannaeyjar on the island of Heimaey, Iceland. Before the eruption was over, approximately one-third of the town of Vestmannaeyjar had been obliterated but, more importantly, the potential damage had been reduced markedly by the spraying of seawater onto the advancing lava flows, causing them to be slowed, stopped, or diverted from the undamaged portion of the town. The Survey's interest and involvement in the Heimaey eruption in Iceland was occasioned by the possibility that the procedures used to control the course of the flowing lava and to reduce the damage in a modern town may some day be needed in Hawaii and possibly even in the continental United States. This publication is based on the observations of two USGS geologists, Richard S. Williams, Jr. and James G. Moore, as well as on information from the Icelandic Ministry for Foreign Affairs, Icelandic scientists' reports through the Center for Short-Lived Phenomena, and other published scientific reports. A number of Icelandic scientists studied the scientific aspects of the eruption and the engineering aspects of the control of lava flows, in particular, Professors Thorbjb'rn Sigurgeirsson and Sigurdur Thorarinsson of the University of Iceland Science Institute. Also, Icelandic governmental officials provided logistical and other support, in particular, Mr. Steingnmur Hermannsson, Director, Icelandic National Research Council and Professor Magnus Magnusson, Director, University of Iceland Science Institute.

  12. Brillouin-Wigner theory for high-frequency expansion in periodically driven systems: Application to Floquet topological insulators

    NASA Astrophysics Data System (ADS)

    Mikami, Takahiro; Kitamura, Sota; Yasuda, Kenji; Tsuji, Naoto; Oka, Takashi; Aoki, Hideo

    2016-04-01

    We construct a systematic high-frequency expansion for periodically driven quantum systems based on the Brillouin-Wigner (BW) perturbation theory, which generates an effective Hamiltonian on the projected zero-photon subspace in the Floquet theory, reproducing the quasienergies and eigenstates of the original Floquet Hamiltonian up to desired order in 1 /ω , with ω being the frequency of the drive. The advantage of the BW method is that it is not only efficient in deriving higher-order terms, but even enables us to write down the whole infinite series expansion, as compared to the van Vleck degenerate perturbation theory. The expansion is also free from a spurious dependence on the driving phase, which has been an obstacle in the Floquet-Magnus expansion. We apply the BW expansion to various models of noninteracting electrons driven by circularly polarized light. As the amplitude of the light is increased, the system undergoes a series of Floquet topological-to-topological phase transitions, whose phase boundary in the high-frequency regime is well explained by the BW expansion. As the frequency is lowered, the high-frequency expansion breaks down at some point due to band touching with nonzero-photon sectors, where we find numerically even more intricate and richer Floquet topological phases spring out. We have then analyzed, with the Floquet dynamical mean-field theory, the effects of electron-electron interaction and energy dissipation. We have specifically revealed that phase transitions from Floquet-topological to Mott insulators emerge, where the phase boundaries can again be captured with the high-frequency expansion.

  13. High performance computing and communications grand challenges program

    SciTech Connect

    Solomon, J.E.; Barr, A.; Chandy, K.M.; Goddard, W.A., III; Kesselman, C.

    1994-10-01

    The so-called protein folding problem has numerous aspects, however it is principally concerned with the {ital de novo} prediction of three-dimensional (3D) structure from the protein primary amino acid sequence, and with the kinetics of the protein folding process. Our current project focuses on the 3D structure prediction problem which has proved to be an elusive goal of molecular biology and biochemistry. The number of local energy minima is exponential in the number of amino acids in the protein. All current methods of 3D structure prediction attempt to alleviate this problem by imposing various constraints that effectively limit the volume of conformational space which must be searched. Our Grand Challenge project consists of two elements: (1) a hierarchical methodology for 3D protein structure prediction; and (2) development of a parallel computing environment, the Protein Folding Workbench, for carrying out a variety of protein structure prediction/modeling computations. During the first three years of this project, we are focusing on the use of two proteins selected from the Brookhaven Protein Data Base (PDB) of known structure to provide validation of our prediction algorithms and their software implementation, both serial and parallel. Both proteins, protein L from {ital peptostreptococcus magnus}, and {ital streptococcal} protein G, are known to bind to IgG, and both have an {alpha} {plus} {beta} sandwich conformation. Although both proteins bind to IgG, they do so at different sites on the immunoglobin and it is of considerable biological interest to understand structurally why this is so. 12 refs., 1 fig.

  14. Lattice Boltzmann method simulations of Stokes number effects on particle motion in a channel flow

    NASA Astrophysics Data System (ADS)

    Zhang, Lenan; Jebakumar, Anand Samuel; Abraham, John

    2016-06-01

    In a recent experimental study by Lau and Nathan ["Influence of Stokes number on the velocity and concentration distributions in particle-laden jets," J. Fluid Mech. 757, 432 (2014)], it was found that particles in a turbulent pipe flow tend to migrate preferentially toward the wall or the axis depending on their Stokes number (St). Particles with a higher St (>10) are concentrated near the axis while those with lower St (<1) move toward the walls. Jebakumar et al. ["Lattice Boltzmann method simulations of Stokes number effects on particle trajectories in a wall-bounded flow," Comput. Fluids 124, 208 (2016)] have carried out simulations of a particle in a laminar channel flow to investigate this behavior. In their work, they report a similar behavior where particles with low St migrate toward the wall and oscillate about a mean position near the wall while those with high St oscillate about the channel center plane. They have explained this behavior in terms of the Saffman lift, Magnus lift, and wall repulsion forces acting on the particle. The present work extends the previous work done by Jebakumar et al. and aims to study the behavior of particles at intermediate St ranging from 10 to 20. It is in this range where the equilibrium position of the particle changes from near the wall to the axis and the particle starts oscillating about the axis. The Lattice Boltzmann method is employed to carry out this study. It is shown that the change in mean equilibrium position is related to increasing oscillations of the particle with mean position near the wall which results in the particle moving past the center plane to the opposite side. The responsible mechanisms are explained in detail.

  15. New constraints on the 3D shear wave velocity structure of the upper mantle underneath Southern Scandinavia revealed from non-linear tomography

    NASA Astrophysics Data System (ADS)

    Wawerzinek, B.; Ritter, J. R. R.; Roy, C.

    2013-08-01

    We analyse travel times of shear waves, which were recorded at the MAGNUS network, to determine the 3D shear wave velocity (vS) structure underneath Southern Scandinavia. The travel time residuals are corrected for the known crustal structure of Southern Norway and weighted to account for data quality and pick uncertainties. The resulting residual pattern of subvertically incident waves is very uniform and simple. It shows delayed arrivals underneath Southern Norway compared to fast arrivals underneath the Oslo Graben and the Baltic Shield. The 3D upper mantle vS structure underneath the station network is determined by performing non-linear travel time tomography. As expected from the residual pattern the resulting tomographic model shows a simple and continuous vS perturbation pattern: a negative vS anomaly is visible underneath Southern Norway relative to the Baltic Shield in the east with a contrast of up to 4% vS and a sharp W-E dipping transition zone. Reconstruction tests reveal besides vertical smearing a good lateral reconstruction of the dipping vS transition zone and suggest that a deep-seated anomaly at 330-410 km depth is real and not an inversion artefact. The upper part of the reduced vS anomaly underneath Southern Norway (down to 250 km depth) might be due to an increase in lithospheric thickness from the Caledonian Southern Scandes in the west towards the Proterozoic Baltic Shield in Sweden in the east. The deeper-seated negative vS anomaly (330-410 km depth) could be caused by a temperature anomaly possibly combined with effects due to fluids or hydrous minerals. The determined simple 3D vS structure underneath Southern Scandinavia indicates that mantle processes might influence and contribute to a Neogene uplift of Southern Norway.

  16. Marginal zone B-cells, a gatekeeper of innate immunity.

    PubMed

    Zouali, Moncef; Richard, Yolande

    2011-01-01

    To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B lymphocytes were initially thought to only play a role in the adaptive branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ) and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount a local antibody response against type-2 T-cell-independent (TI-2) antigens, MZ B-cells can participate to T-cell-dependent (TD) immune responses through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in humans, non-human primates, and rodents. We also summarize studies - performed in transgenic mice expressing fully human antibodies on their B-cells and in macaques whose infection with Simian immunodeficiency virus (SIV) represents a suitable model for HIV-1 infection in humans - showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus) as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells - MZ B-cells and/or B1 B-cells - with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies. PMID:22566852

  17. Micro, meso, macro

    NASA Astrophysics Data System (ADS)

    Liljenström, Hans; Svedin, Uno

    1. System features, dynamics, and resilience - some introductory remarks / Hans Liljenström & Uno Svedin -- pt. I. The "vertical" system structure and meso-level characteristics. 2. Mesoscopic levels in science - some comments / Hermann Haken. 3. The necessity for mesoscopic organization to connect neural function to brain function / Walter J. Freeman. 4. Dynamic state transitions in the nervous system: from ion channels to neurons to networks / Peter Århem ... [et al.]. 5. A revolution in the Middle Kingdom / Robert E. Ulanowicz. 6. The meso-scale level of self-maintained reflective systems / Abir U. Igamberdiev -- pt. II. Inner and outer dynamics. 7. Time rescaling and generalized entropy in relation to the internal measurement concept / Igor Rojdestvenski & Michael G. Cottam. 8. Studying dynamic and stochastic systems using Poisson simulation / Leif Gustafsson. 9. Resource dynamics, social interactions, and the tragedy of the commons / Alia Mashanova & Richard Law. 10. Stability of social interaction / Sjur D. Flåm -- pt. III. Resilience and shocks. 11. Systems, shocks and time bombs / Nick Winder. 12. Biodiversity decreases the risk of collapse in model food webs / Charlotte Borrvall, Maria Christianou & Bo Ebenman. 13. A long-term perspective on resilience in socio-natural systems / Sander E. van der Leeuw & Christina Aschan-Leygonie. 14. Resilience in utility technologies / Roger Seaton. 15. Economic growth under shocks: path dependencies and stabilization / Yuri M. Ermoliev, Tatiana Y. Ermolieva & Vladimir I. Norkin. 16. Risk and crises management in complex systems / Koen Bertels, Jean-Marie Jacques & Magnus Boman. 17. Bridges, connections and interfaces - reflections over the meso theme / Uno Svedin & Hans Liljenström.

  18. Work-family conflict and self-discrepant time allocation at work.

    PubMed

    Dahm, Patricia C; Glomb, Theresa M; Manchester, Colleen Flaherty; Leroy, Sophie

    2015-05-01

    We examine the relationships between work-to-family conflict, time allocation across work activities, and the outcomes of work satisfaction, well-being, and salary in the context of self-regulation and self-discrepancy theories. We posit work-to-family conflict is associated with self-discrepant time allocation such that employees with higher levels of work-to-family conflict are likely to allocate less time than preferred to work activities that require greater self-regulatory resources (e.g., tasks that are complex, or those with longer term goals that delay rewards and closure) and allocate more time than preferred to activities that demand fewer self-regulatory resources or are replenishing (e.g., those that provide closure or are prosocial). We suggest this self-discrepant time allocation (actual vs. preferred time allocation) is one mechanism by which work-to-family conflict leads to negative employee consequences (Allen, Herst, Bruck, & Sutton, 2000; Mesmer-Magnus & Viswesvaran, 2005). Using polynomial regression and response surface methodology, we find that discrepancies between actual and preferred time allocations to work activities negatively relate to work satisfaction, psychological well-being, and physical well-being. Self-discrepant time allocation mediates the relationship between work-to-family conflict and work satisfaction and well-being, while actual time allocation (rather than the discrepancy) mediates the relationship between work-to-family conflict and salary. We find that women are more likely than men to report self-discrepant time allocations as work-to-family conflict increases. PMID:25664468

  19. Hemosporidian blood parasites in seabirds—a comparative genetic study of species from Antarctic to tropical habitats

    PubMed Central

    Martínez, Javier; Hennicke, Janos; Ludynia, Katrin; Gladbach, Anja; Masello, Juan F.; Riou, Samuel; Merino, Santiago

    2010-01-01

    Whereas some bird species are heavily affected by blood parasites in the wild, others reportedly are not. Seabirds, in particular, are often free from blood parasites, even in the presence of potential vectors. By means of polymerase chain reaction, we amplified a DNA fragment from the cytochrome b gene to detect parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus in 14 seabird species, ranging from Antarctica to the tropical Indian Ocean. We did not detect parasites in 11 of these species, including one Antarctic, four subantarctic, two temperate, and four tropical species. On the other hand, two subantarctic species, thin-billed prions Pachyptila belcheri and dolphin gulls Larus scoresbii, were found infected. One of 28 thin-billed prions had a Plasmodium infection whose DNA sequence was identical to lineage P22 of Plasmodium relictum, and one of 20 dolphin gulls was infected with a Haemoproteus lineage which appears phylogenetically clustered with parasites species isolated from passeriform birds such as Haemoproteus lanii, Haemoproteus magnus, Haemoproteus fringillae, Haemoproteus sylvae, Haemoproteus payevskyi, and Haemoproteus belopolskyi. In addition, we found a high parasite prevalence in a single tropical species, the Christmas Island frigatebird Fregata andrewsi, where 56% of sampled adults were infected with Haemoproteus. The latter formed a monophyletic group that includes a Haemoproteus line from Eastern Asian black-tailed gulls Larus crassirostris. Our results are in agreement with those showing that (a) seabirds are poor in hemosporidians and (b) latitude could be a determining factor to predict the presence of hemosporidians in birds. However, further studies should explore the relative importance of extrinsic and intrinsic factors on parasite prevalence, in particular using phylogenetically controlled comparative analyses, systematic sampling and screening of vectors, and within-species comparisons. PMID:20652673

  20. A Modification and Analysis of Lagrangian Trajectory Modeling and Granular Dynamics of Lunar Dust Particles

    NASA Technical Reports Server (NTRS)

    Long, Jason M.; Lane, John E.; Metzger, Philip T.

    2008-01-01

    A previously developed mathematical model is amended to more accurately incorporate the effects of lift and drag on single dust particles in order to predict their behavior in the wake of high velocity gas flow. The model utilizes output from a CFD or DSMC simulation of exhaust from a rocket nozzle hot gas jet. An extension of the Saffman equation for lift based on the research of McLaughlin (1991) and Mei (1992) is used, while an equation for the Magnus force modeled after the work of Oesterle (1994) and Tsuji et al (1985) is applied. A relationship for drag utilizing a particle shape factor (phi = 0.8) is taken from the work of Haider and Levenspiel (1989) for application to non-spherical particle dynamics. The drag equation is further adjusted to account for rarefaction and compressibility effects in rarefied and high Mach number flows according to the work of Davies (1945) and Loth (2007) respectively. Simulations using a more accurate model with the correction factor (Epsilon = 0.8 in a 20% particle concentration gas flow) given by Richardson and Zaki (1954) and Rowe (1961) show that particles have lower ejection angles than those that were previously calculated. This is more prevalent in smaller particles, which are shown through velocity and trajectory comparison to be more influenced by the flow of the surrounding gas. It is shown that particles are more affected by minor changes to drag forces than larger adjustments to lift forces, demanding a closer analysis of the shape and behavior of lunar dust particles and the composition of the surrounding gas flow.

  1. Toward an In Vivo Neuroimaging Template of Human Brainstem Nuclei of the Ascending Arousal, Autonomic, and Motor Systems.

    PubMed

    Bianciardi, Marta; Toschi, Nicola; Edlow, Brian L; Eichner, Cornelius; Setsompop, Kawin; Polimeni, Jonathan R; Brown, Emery N; Kinney, Hannah C; Rosen, Bruce R; Wald, Lawrence L

    2015-12-01

    Brainstem nuclei (Bn) in humans play a crucial role in vital functions, such as arousal, autonomic homeostasis, sensory and motor relay, nociception, sleep, and cranial nerve function, and they have been implicated in a vast array of brain pathologies. However, an in vivo delineation of most human Bn has been elusive because of limited sensitivity and contrast for detecting these small regions using standard neuroimaging methods. To precisely identify several human Bn in vivo, we employed a 7 Tesla scanner equipped with multi-channel receive-coil array, which provided high magnetic resonance imaging sensitivity, and a multi-contrast (diffusion fractional anisotropy and T2-weighted) echo-planar-imaging approach, which provided complementary contrasts for Bn anatomy with matched geometric distortions and resolution. Through a combined examination of 1.3 mm(3) multi-contrast anatomical images acquired in healthy human adults, we semi-automatically generated in vivo probabilistic Bn labels of the ascending arousal (median and dorsal raphe), autonomic (raphe magnus, periaqueductal gray), and motor (inferior olivary nuclei, two subregions of the substantia nigra compatible with pars compacta and pars reticulata, two subregions of the red nucleus, and, in the diencephalon, two subregions of the subthalamic nucleus) systems. These labels constitute a first step toward the development of an in vivo neuroimaging template of Bn in standard space to facilitate future clinical and research investigations of human brainstem function and pathology. Proof-of-concept clinical use of this template is demonstrated in a minimally conscious patient with traumatic brainstem hemorrhages precisely localized to the raphe Bn involved in arousal. PMID:26066023

  2. Multiple vacancy production by high energy heavy ions

    SciTech Connect

    Becker, R.L.; Ford, A.L.; Reading, J.F.

    1984-01-01

    The theory of atomic collisions has two ingredients: collision theory and atomic structure theory. The collision theories differ with respect to (A) the collision dynamics and (B) the treatment of the relative motion of the projectile and target nuclei. With regard to the dynamics multiple vacancy production is of fundamental interest because it is a signature for and probe of strong interactions between the projectile and the target electrons. For projectiles of large nuclear charge, Z/sub p/, especially for those which are highly stripped so as to have a large ionic charge, q, the interaction becomes strong enough to give a high probability of multiple vacancy production and a breakdown of perturbation theory. The familiar first and second Born approximations and their off-shoots cease to be adequate. Not even the recent strong-potential Born approximation (see Taulbjerg 1984) is sufficient, because the weaker of the potentials generated by the projectile and the target nuclei, respectively, is treated in first order. One needs a unitary, non-perturbative collision theory. At present this is generally available for multiple vacancy production only in the form of the highly numerical coupled channels theory (Becker et al. 1983, 1984b). For special problems analytically tractable models have been devised. For example, a simple, unitary, geometrical encounter probability model for the calculation of p/sub L/(0), the inclusive L-shell vacancy probability per electron in collisions with impact parameter B = 0, has been introduced by Sulik et al. (1984) and further developed by Sulik and Hock (1984). Along with earlier coupled-channels calculations (Becker et al. 1984ab) and first Magnus calculations (Becker et al. 1984b), this model is able to describe the saturation of p/sub L/(0) with Z/sub p/ at fixed impact speed, v, whereas all the first-order theories predict p/sub L/ proportional to Z/sub p//sup 2/, which eventually exceeds unity.

  3. Hemosporidian blood parasites in seabirds—a comparative genetic study of species from Antarctic to tropical habitats

    NASA Astrophysics Data System (ADS)

    Quillfeldt, Petra; Martínez, Javier; Hennicke, Janos; Ludynia, Katrin; Gladbach, Anja; Masello, Juan F.; Riou, Samuel; Merino, Santiago

    2010-09-01

    Whereas some bird species are heavily affected by blood parasites in the wild, others reportedly are not. Seabirds, in particular, are often free from blood parasites, even in the presence of potential vectors. By means of polymerase chain reaction, we amplified a DNA fragment from the cytochrome b gene to detect parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus in 14 seabird species, ranging from Antarctica to the tropical Indian Ocean. We did not detect parasites in 11 of these species, including one Antarctic, four subantarctic, two temperate, and four tropical species. On the other hand, two subantarctic species, thin-billed prions Pachyptila belcheri and dolphin gulls Larus scoresbii, were found infected. One of 28 thin-billed prions had a Plasmodium infection whose DNA sequence was identical to lineage P22 of Plasmodium relictum, and one of 20 dolphin gulls was infected with a Haemoproteus lineage which appears phylogenetically clustered with parasites species isolated from passeriform birds such as Haemoproteus lanii, Haemoproteus magnus, Haemoproteus fringillae, Haemoproteus sylvae, Haemoproteus payevskyi, and Haemoproteus belopolskyi. In addition, we found a high parasite prevalence in a single tropical species, the Christmas Island frigatebird Fregata andrewsi, where 56% of sampled adults were infected with Haemoproteus. The latter formed a monophyletic group that includes a Haemoproteus line from Eastern Asian black-tailed gulls Larus crassirostris. Our results are in agreement with those showing that (a) seabirds are poor in hemosporidians and (b) latitude could be a determining factor to predict the presence of hemosporidians in birds. However, further studies should explore the relative importance of extrinsic and intrinsic factors on parasite prevalence, in particular using phylogenetically controlled comparative analyses, systematic sampling and screening of vectors, and within-species comparisons.

  4. The identification and neurochemical characterization of central neurons that target parasympathetic preganglionic neurons involved in the regulation of choroidal blood flow in the rat eye using pseudorabies virus, immunolabeling and conventional pathway tracing methods

    PubMed Central

    Li, Chunyan; Fitzgerald, Malinda E. C.; Del Mar, Nobel; Cuthbertson-Coates, Sherry; LeDoux, Mark S.; Gong, Suzhen; Ryan, James P.; Reiner, Anton

    2015-01-01

    The choroidal blood vessels of the eye provide the main vascular support to the outer retina. These blood vessels are under parasympathetic vasodilatory control via input from the pterygopalatine ganglion (PPG), which in turn receives its preganglionic input from the superior salivatory nucleus (SSN) of the hindbrain. The present study characterized the central neurons projecting to the SSN neurons innervating choroidal PPG neurons, using pathway tracing and immunolabeling. In the initial set of studies, minute injections of the Bartha strain of the retrograde transneuronal tracer pseudorabies virus (PRV) were made into choroid in rats in which the superior cervical ganglia had been excised (to prevent labeling of sympathetic circuitry). Diverse neuronal populations beyond the choroidal part of ipsilateral SSN showed transneuronal labeling, which notably included the parvocellular part of the paraventricular nucleus of the hypothalamus (PVN), the periaqueductal gray, the raphe magnus (RaM), the B3 region of the pons, A5, the nucleus of the solitary tract (NTS), the rostral ventrolateral medulla (RVLM), and the intermediate reticular nucleus of the medulla. The PRV+ neurons were located in the parts of these cell groups that are responsive to systemic blood pressure signals and involved in systemic blood pressure regulation by the sympathetic nervous system. In a second set of studies using PRV labeling, conventional pathway tracing, and immunolabeling, we found that PVN neurons projecting to SSN tended to be oxytocinergic and glutamatergic, RaM neurons projecting to SSN were serotonergic, and NTS neurons projecting to SSN were glutamatergic. Our results suggest that blood pressure and volume signals that drive sympathetic constriction of the systemic vasculature may also drive parasympathetic vasodilation of the choroidal vasculature, and may thereby contribute to choroidal baroregulation during low blood pressure. PMID:26082687

  5. Conditional depletion of methyl-CpG-binding protein 2 in astrocytes depresses the hypercapnic ventilatory response in mice.

    PubMed

    Garg, Saurabh K; Lioy, Daniel T; Knopp, Sharon J; Bissonnette, John M

    2015-09-15

    Mice that are deficient in the transcription factor methyl-CpG-binding protein 2 (MeCP2) have a depressed hypercapnic ventilatory response (HCVR). The expression of MeCP2 can be selectively removed from astrocytes or neurons, thus offering a tool to dissect the role of this transcription factor in astrocytes from that in neurons. Studies were carried out in the progeny of mice that were a cross between those harboring a tamoxifen (TAM)-inducible Cre recombinase transgene driven by the human astrocytic glial fibrillary acidic protein (hGFAP) promoter, or Cre recombinase under control of the synapsin promoter, with mice containing a Cre-excisable exon III in the Mecp2 gene. The TAM-conditional excision of the Mecp2 exon allowed the respiratory CO2 response to be studied in the same animals before and after selective depletion of MeCP2 in astrocytes. Immunohistochemistry showed that following TAM treatment only ∼20% of GFAP-labeled cells in the retrotrapazoid nucleus and in the raphé magnus were positive for MeCP2. The slope of the relative increase in minute ventilation as a function of 1, 3, and 5% inspired CO2 was depressed in mice with depleted astrocyte MeCP2 compared with wild-type littermates. In contrast, selective depletion of MeCP2 in neurons did not significantly affect slope. While neurons which constitute the respiratory network ultimately determine the ventilatory response to CO2, this study demonstrates that loss of MeCP2 in astrocytes alone is sufficient to result in a dramatic attenuation of the HCVR. We propose that the glial contribution to HCVR is under the control of the MeCP2 gene. PMID:26205541

  6. Medullary raphe neurones and baroreceptor modulation of the respiratory motor pattern in the cat

    PubMed Central

    Lindsey, B G; Arata, A; Morris, K F; Hernandez, Y M; Shannon, R

    1998-01-01

    Perturbations of arterial blood pressure change medullary raphe neurone activity and the respiratory motor pattern. This study sought evidence for actions of baroresponsive raphe neurones on the medullary respiratory network.Blood pressure was perturbed by intravenous injection of an α1-adrenergic receptor agonist, unilateral pressure changes in the carotid sinus, or occlusion of the descending aorta in thirty-six Dial-urethane-anaesthetized, vagotomized, paralysed, artificially ventilated cats. Neurones were monitored with microelectrode arrays in two or three of the following domains: nucleus raphe obscurus-nucleus raphe pallidus, nucleus raphe magnus, and rostral and caudal ventrolateral medulla. Data were analysed with cycle-triggered histograms, peristimulus time and cumulative sum histograms, cross-correlograms and spike-triggered averages of efferent phrenic nerve activity.Prolongation of the expiratory phase and decreased peak integrated phrenic amplitude were most frequently observed. Of 707 neurones studied, 310 had altered firing rates during stimulation; changes in opposite directions were monitored simultaneously in fifty-six of eighty-seven data sets with at least two baroresponsive neurones.Short time scale correlations were detected between neurones in 347 of 3388 pairs. Seventeen pairs of baroresponsive raphe neurones exhibited significant offset correlogram features indicative of paucisynaptic interactions. In correlated raphe-ventrolateral medullary neurone pairs with at least one baroresponsive neurone, six of seven ventrolateral medullary decrementing expiratory (E-Decr) neurones increased their firing rate during baroreceptor stimulation. Thirteen of fifteen ventrolateral medullary inspiratory neurones correlated with raphe cells decreased their firing rate during baroreceptor stimulation.The results support the hypothesis that raphe neuronal assemblies transform and transmit information from baroreceptors to neurones in the ventral

  7. Hypoxia and electrical stimulation of the carotid sinus nerve induce Fos-like immunoreactivity within catecholaminergic and serotoninergic neurons of the rat brainstem.

    PubMed

    Erickson, J T; Millhorn, D E

    1994-10-01

    A complete understanding of the neural mechanisms responsible for the chemoreceptor and baroreceptor reflexes requires precise knowledge of the locations and chemical phenotypes of higher-order neurons within these reflex pathways. In the present study, the protein product (Fos) of the c-fos protooncogene was used as a metabolic marker to trace central neural pathways following activation of carotid sinus nerve afferent fibers. In addition, immunohistochemical double-labeling techniques were used to define the chemical phenotypes of activated neurons. Both electrical stimulation of the carotid sinus nerve and physiological stimulation of the carotid bodies by hypoxia induced Fos-like immunoreactivity in catecholaminergic neurons containing tyrosine hydroxylase or phenylethanolamine-N-methyltransferase in the ventrolateral medulla oblongata and, to a lesser degree, in the dorsal vagal complex. Tyrosine hydroxylase/Fos colocalization was also observed in the locus coeruleus and the A5 noradrenergic cell group in pons. Many serotoninergic neurons in nucleus raphe pallidus, nucleus raphe magnus, and along the ventral medullary surface contained Fos-like immunoreactivity. In pons and midbrain, Fos-like immunoreactivity was observed in the lateral parabrachial and Kölliker-Fuse nuclei, the inferior colliculus, the cuneiform nucleus, and in the vicinity of the Edinger-Westphal nucleus, but no catecholaminergic or serotoninergic colocalization was observed in these regions. Although Fos-labeled cells were observed within and lateral to the dorsal raphe nucleus, few were catecholaminergic or serotoninergic. This study further defines a potential central neuroanatomical substrate for the chemoreceptor and/or baroreceptor reflexes. PMID:7814687

  8. Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study

    PubMed Central

    Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald

    2015-01-01

    Objective Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman’s ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. Materials and methods This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Results Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. Conclusion In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the

  9. Phylogeny and biogeography of Asthenopodinae with a revision of Asthenopus, reinstatement of Asthenopodes, and the description of the new genera Hubbardipes and Priasthenopus (Ephemeroptera, Polymitarcyidae)

    PubMed Central

    Molineri, Carlos; Salles, Frederico F.; Peters, Janice G.

    2015-01-01

    Abstract The Neotropical species of Asthenopodinae are revised in a formal phylogenetic context. The five known species of Asthenopus Eaton, 1871, together with other five new species were included in a cladistic analysis using morphological characters (continuous and discretes). Representatives of the Afro-Oriental group of the subfamily (Povilla Navás, 1912 and Languidipes Hubbard, 1984) were also included to test the monophyletic hypothesis traditionally accepted for the group. Additional taxa representing the other subfamilies of Polymitarcyidae were incorparated: Ephoron Williamson, 1802 (Polymitarcyinae) and Campsurus Eaton, 1868, Tortopus Needham & Murphy, 1924 and Tortopsis Molineri, 2010 (Campsurinae). A matrix of 17 taxa and 72 characters was analyzed under parsimony resulting in a single tree supporting the monophyly of the subfamily Asthenopodinae. Other results include the monophyly of the Afro-Oriental taxa (Povilla and Languidipes), the paraphyletic nature of Neotropical Asthenopodinae, and the recognition of four South American genera: Asthenopus (including Asthenopus curtus (Hagen), 1861, Asthenopus angelae de Souza & Molineri, 2012, Asthenopus magnus sp. n., Asthenopus hubbardi sp. n., Asthenopus guarani sp. n.), Asthenopodes Ulmer, 1924, stat. n. (including Asthenopus picteti Hubbard, 1975, stat. n., Asthenopodes traverae sp. n., Asthenopodes chumuco sp. n.), Priasthenopus gen. n. (including Priasthenopus gilliesi (Domínguez), 1988, comb. n.), and Hubbardipes gen. n. (including Hubbardipes crenulatus (Molineri et al.), 2011, comb. n.). Descriptions, diagnoses, illustrations and keys are presented for all Neotropical taxa of Asthenopodinae (adults of both sexes, eggs and nymphs). Additionally a key to the subfamilies and genera of Polymitarcyidae is included. A quantitative biogeographic analysis of vicariance is presented and discussed through the study of the “taxon history” of the group. PMID:25685010

  10. Temperature and relative humidity distributions in a medium-size administrative town in southwest Nigeria.

    PubMed

    Akinbode, O M; Eludoyin, A O; Fashae, O A

    2008-04-01

    This study was carried out in one of the medium-sized public administrative towns in the southwestern part of Nigeria. Its aim is to highlight the effect of spatial distribution of settlements, population, and socio-economic activities on urban air temperature and humidity in the town. Temperature and relative humidity data from 1992 to 2001 were obtained from three meteorological stations in Akure, the Administrative Capital of Ondo State, Nigeria. The stations are located within the Federal Ministry of Aviation, Akure Airport (FMA), Federal University of Technology, Akure (FUTA) and Federal School of Agriculture (SOA). Air temperature and relative humidity measurements were also obtained from 27 points, which were cited to include road junctions, markets, built up areas, etc., using sling psychrometer. The data were subsequently analysed for spatial and temporal variations using statistical packages (SPSS and Microsoft Excel) and isolines. Actual vapour pressure and dew point temperature were computed using Magnus conversion formulae. The results obtained showed that spatial variation was insignificant, in terms of the temperature and humidity variables. The annual mean temperature (Tmean) ranged between 21.9 and 30.4 degrees C while minimum (Tmin) and maximum (Tmax) temperatures varied from 13 to 26 and 21.5-39.6 degrees C, respectively. Relative humidity (RH), actual vapour pressure (Es) and dew point temperature (Td) values also varied from 39.1% to 98.2%, 19.7-20.8 gm(-3), and 17.3-17.8 degrees C, respectively. A significant relationship (p>0.6; r<0.05) between Tmin, Es and Td was observed while the daytime 'urban heat island' intensity (UHI) ranged between 0.5 and 2.5 degrees C within the study period. The study concluded that there is influence of urban canopy on the microclimate of Akure, and hypothesizes that the urban dwellers may be subjected to some levels of weather related physiological disorderliness. PMID:17482750

  11. Normalized Lift: An Energy Interpretation of the Lift Coefficient Simplifies Comparisons of the Lifting Ability of Rotating and Flapping Surfaces

    PubMed Central

    Burgers, Phillip; Alexander, David E.

    2012-01-01

    For a century, researchers have used the standard lift coefficient CL to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½ρv2, where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex adjustments as is the case for flapping wings and rotating cylinders. This paper interprets the standard lift coefficient of a fixed wing slightly differently, as the work exerted by the wing on the surrounding flow field (L/ρ·S), compared against the total kinetic energy required for generating said lift, ½v2. This reinterpreted coefficient, the normalized lift, is derived from the work-energy theorem and compares the lifting capabilities of dissimilar lift systems on a similar energy footing. The normalized lift is the same as the standard lift coefficient for fixed wings, but differs for wings with more complex motions; it also accounts for such complex motions explicitly and without complex modifications or adjustments. We compare the normalized lift with the previously-reported values of lift coefficient for a rotating cylinder in Magnus effect, a bat during hovering and forward flight, and a hovering dipteran. The maximum standard lift coefficient for a fixed wing without flaps in steady flow is around 1.5, yet for a rotating cylinder it may exceed 9.0, a value that implies that a rotating cylinder generates nearly 6 times the maximum lift of a wing. The maximum normalized lift for a rotating cylinder is 1.5. We suggest that the normalized lift can be used to evaluate propellers, rotors, flapping wings of animals and micro air vehicles, and underwater thrust-generating fins in the same way the lift coefficient is currently used to evaluate fixed wings. PMID:22629326

  12. Development and Validation of a High Anatomical Fidelity FE Model for the Buttock and Thigh of a Seated Individual.

    PubMed

    Al-Dirini, Rami M A; Reed, Matthew P; Hu, Jingwen; Thewlis, Dominic

    2016-09-01

    Current practices for designing new cushions for seats depend on superficial measurements, such as pressure mapping, which do not provide sufficient information about the condition of sub-dermal tissues. Finite element (FE) modelling offers a unique alternative to integrate assessment of sub-dermal tissue condition into seat/cushion design and development processes. However, the development and validation of such FE models for seated humans requires accurate representation of the anatomy and material properties, which remain challenges that are yet to be addressed. This paper presents the development and validation of a detailed 3D FE model with high anatomical fidelity of the buttock and thigh, for a specific seated subject. The developed model consisted of 28 muscles, the pelvis, sacrum, femur, and one layer of inter-muscular fat, subcutaneous fat and skin. Validation against in vivo measurements from MRI data confirmed that the FE model can simulate the deformation of soft tissues under sitting loads with an accuracy of (mean ± SD) 4.7 ± 4.4 mm. Simulation results showed that the maximum strains (compressive, shear and von-Mises) on muscles (41, 110, 79%) were higher than fat tissues (21, 62, 41%). The muscles that experienced the highest mechanical loads were the gluteus maximus, adductor magnus and muscles in the posterior aspect of the thighs (biceps femoris, semitendinosus and semimembranosus muscles). The developed FE model contributes to the progression towards bio-fidelity in modelling the human body in seated postures by providing insight into the distribution of stresses/strains in individual muscles and inter-muscular fat in the buttock and thigh of seated individuals. Industrial applications for the developed FE model include improving the design of office and household furniture, automotive and airplane seats and wheelchairs as well as customisation and assessment of sporting and medical equipment to meet individual requirements. PMID:26857008

  13. Comparison of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and Molecular Biology Techniques for Identification of Culicoides (Diptera: Ceratopogonidae) Biting Midges in Senegal

    PubMed Central

    Sambou, Masse; Aubadie-Ladrix, Maxence; Fenollar, Florence; Fall, Becaye; Bassene, Hubert; Almeras, Lionel; Sambe-Ba, Bissoume; Perrot, Nadine; Chatellier, Sonia; Faye, Ngor; Parola, Philippe; Wade, Boubacar; Raoult, Didier

    2014-01-01

    Biting midges of the genus Culicoides are implicated as vectors for a wide variety of pathogens. The morphological identification of these arthropods may be difficult because of a lack of detailed investigation of taxonomy for this species in Africa. However, matrix-assisted laser desorption ionization−time of flight mass spectrometry (MALDI-TOF MS) profiling is efficient for arthropod identification at the species level. This study established a spectrum database of Culicoides spp. from Senegal using MALDI-TOF. Identification of Culicoides insects to the species level before mass spectrometry was performed on the basis of morphological characters. MALDI-TOF MS reference spectra were determined for 437 field-caught Culicoides of 10 species. The protein profiles of all tested Culicoides revealed several peaks with mass ranges of 2 to 20 kDa. In a validation study, 72 Culicoides specimens in the target species were correctly identified at the species level with a similarity of 95 to 99.9%. Four Culicoides protein profiles were misidentified. Nevertheless, six SuperSpectra (C. imicola, C. enderleini, C. oxystoma, C. kingi, C. magnus, and C. fulvithorax) were created. Abdomens of midges were used to amplify and sequence a portion of the mitochondrial cytochrome oxidase I gene (COI). The results obtained using the MALDI-TOF MS method were consistent with the morphological identification and similar to the genetic identification. Protein profiling using MALDI-TOF is an efficient approach for the identification of Culicoides spp., and it is economically advantageous for approaches that require detailed and quantitative information of vector species that are collected in field. The database of African Culicoides MS spectra created is the first database in Africa. The COI sequences of five Culicoides species that were previously noncharacterized using molecular methods were deposited in GenBank. PMID:25411169

  14. Hydrodynamics of sediment threshold

    NASA Astrophysics Data System (ADS)

    Ali, Sk Zeeshan; Dey, Subhasish

    2016-07-01

    A novel hydrodynamic model for the threshold of cohesionless sediment particle motion under a steady unidirectional streamflow is presented. The hydrodynamic forces (drag and lift) acting on a solitary sediment particle resting over a closely packed bed formed by the identical sediment particles are the primary motivating forces. The drag force comprises of the form drag and form induced drag. The lift force includes the Saffman lift, Magnus lift, centrifugal lift, and turbulent lift. The points of action of the force system are appropriately obtained, for the first time, from the basics of micro-mechanics. The sediment threshold is envisioned as the rolling mode, which is the plausible mode to initiate a particle motion on the bed. The moment balance of the force system on the solitary particle about the pivoting point of rolling yields the governing equation. The conditions of sediment threshold under the hydraulically smooth, transitional, and rough flow regimes are examined. The effects of velocity fluctuations are addressed by applying the statistical theory of turbulence. This study shows that for a hindrance coefficient of 0.3, the threshold curve (threshold Shields parameter versus shear Reynolds number) has an excellent agreement with the experimental data of uniform sediments. However, most of the experimental data are bounded by the upper and lower limiting threshold curves, corresponding to the hindrance coefficients of 0.2 and 0.4, respectively. The threshold curve of this study is compared with those of previous researchers. The present model also agrees satisfactorily with the experimental data of nonuniform sediments.

  15. Managing a Female Patient with Left Low Back Pain and Sacroiliac Joint Pain with Therapeutic Exercise: A Case Report

    PubMed Central

    2011-01-01

    ABSTRACT Purpose: The purpose of this case study is to describe the management of a female patient with chronic left low back pain and sacroiliac joint pain (LBP/SIJP) using unique unilateral exercises developed by the Postural Restoration Institute (PRI) to address pelvic asymmetry and left hip capsule restriction, which is consistent with a Right Handed and Left Anterior Interior Chain pattern of postural asymmetry. Client Description: The client was 65-year-old woman with a 10-month history of constant left LBP/SIJP and leg pain. Intervention: The patient was seen six times to correct pelvic position/posture and left hip posterior capsule restriction via (1) muscle activation (left hamstrings, adductor magnus, and anterior gluteus medius) and (2) left hip adduction to lengthen the left posterior capsule/ischiofemoral ligament. Stabilization exercises included bilateral hamstrings, gluteus maximus, adductors, and abdominals to maintain pelvic position/posture. Measures and Outcome: Left Ober's test (initially positive) was negative at discharge. Pain as measured on the Numeric Pain Rating Scale (initially 1/10 at best and 8/10 at worst) was 0/10–0/10 at discharge. Oswestry Disability Index score (initially 20%) was 0% at discharge. The patient no longer had numbness in her left leg, and sexual intercourse had become pain free. Implications: Interventions to restore and maintain the optimal position of pelvis and hip (femoral head in the acetabulum) may be beneficial for treating patients with chronic LBP/SIJP. The patient's pain was eliminated 13 days after she first performed three exercises to reposition the pelvis and restore left posterior hip capsule extensibility and internal rotation. PMID:22379254

  16. Time-variant fMRI activity in the brainstem and higher structures in response to acupuncture.

    PubMed

    Napadow, Vitaly; Dhond, Rupali; Park, Kyungmo; Kim, Jieun; Makris, Nikos; Kwong, Kenneth K; Harris, Richard E; Purdon, Patrick L; Kettner, Norman; Hui, Kathleen K S

    2009-08-01

    Acupuncture modulation of activity in the human brainstem is not well known. This structure is plagued by physiological artifact in neuroimaging experiments. In addition, most studies have used short (<15 min) block designs, which miss delayed responses following longer duration stimulation. We used brainstem-focused cardiac-gated fMRI and evaluated time-variant brain response to longer duration (>30 min) stimulation with verum (VA, electro-stimulation at acupoint ST-36) or sham point (SPA, non-acupoint electro-stimulation) acupuncture. Our results provide evidence that acupuncture modulates brainstem nuclei important to endogenous monoaminergic and opioidergic systems. Specifically, VA modulated activity in the substantia nigra (SN), nucleus raphe magnus, locus ceruleus, nucleus cuneiformis, and periaqueductal gray (PAG). Activation in the ventrolateral PAG was greater for VA compared to SPA. Linearly decreasing time-variant activation, suggesting classical habituation, was found in response to both VA and SPA in sensorimotor (SII, posterior insula, premotor cortex) brain regions. However, VA also produced linearly time-variant activity in limbic regions (amygdala, hippocampus, and SN), which was bimodal and not likely habituation--consisting of activation in early blocks, and deactivation by the end of the run. Thus, acupuncture induces different brain response early, compared to 20-30 min after stimulation. We attribute the fMRI differences between VA and SPA to more varied and stronger psychophysical response induced by VA. Our study demonstrates that acupuncture modulation of brainstem structures can be studied non-invasively in humans, allowing for comparison to animal studies. Our protocol also demonstrates a fMRI approach to study habituation and other time-variant phenomena over longer time durations. PMID:19345268

  17. Experimental investigation of the radiation shielding of a MCP detector in the radiation environment near Europa

    NASA Astrophysics Data System (ADS)

    Tulej, Marek; Wurz, Peter; Meyer, Stefan; Lasi, Davide; Lüthi, Matthias; Galli, André; Piazza, Daniele; Desorgher, Laurent; Hajdas, Wojciech; Reggiani, Davide; Karlsson, Stefan; Kalla, Leif

    2016-04-01

    range of the beam momentum 17.5-345 MeV/c. The MCP measurements yield detection efficiency to the remaining primary radiation and the produced secondary radiation and the determination of beam attenuation coefficients in the range of investigated beam momenta. The studies define key performance parameters for the shielding and show direction for its further improvements. Literature [1] O. Grasset, M. K. Dougherty, A. Coustenis, E. J. Bunce, C. Erd, D. Titov, M. Blanc, A. Coates, P. Drossart, L. N. Fletcher, H. Hussmann, R. Jaumann, N. Krupp, J. P. Lebreton, O. Prieto-Ballesteros, P. Tortora, F. Tosi and T. Van Hoolst Planet Space Sci 78, (2013). [2] P. Wurz, D. Abplanalp, M. Tulej, M. Iakovleva, V. A. Fernandes, A. Chumikov and G. G. Managadze Solar Syst Res 46, (2012). [3] P. Wurz, D. Abplanalp, M. Tulej and H. Lammer Planet Space Sci 74, (2012). 6A. Vorburger, P. Wurz, H. Lammer, S. Barabash and O. Mousis Icarus 262, (2015).[4] M. Tulej, S. Meyer, M. Luthi, D. Lasi, A. Galli, L. Desorgher, W. Hajdas, S. Karlsson, L. Kalla and P. Wurz Rev Sci Instrum 86, (2015).[5] W. Hajdas, L. Desorgher, K. Deiters, D. Reggiani, T. Rauber, T. M., P. Wurz, L. M., K. Wojczuk and P. Kalaczynski Journal of Applied Mathematics and Physics 2, (2014).

  18. Use of microorganisms to improve the cementation of granular structures. Applications in the restoration of monuments

    NASA Astrophysics Data System (ADS)

    González, Isabel; Mayoral, Eduardo; Ortiz, Pilar; Segura, Dolores; Vazquez, Auxiliadora; Barba, Cinta; Ortiz, Rocio; Romero, Antonio

    2015-04-01

    This researching work focuses on the development of new procedures to be applied in heritage rehabilitation, through the implementation of low-cost biotechnological processes in the realm of engineering and architecture. In doing so, it explores the possibilities of MICP (Microbially Induced Calcite Precipitation), which is a biomineralization process applied to improve the engineering properties of granular structures. This is a novelty approach at present, as there are few researches putting together knowledge in biotechnology and mineralogy to by applied in architecture and engineer. Some authors propose the bacteria use to generate habitable structures that reduce desertification (Magnus Larsson 2008). Innovative research teams led by De Jong and the University of California UC Davis (XXXX) study how cement or stabilize soils to prevent landslides, improving the foundation injecting populations of Bacillus pasteurii in the field. Bacterially induced mineralization has emerged as a method for protecting and consolidating decayed ornamental stone, which offers noticeable advantages compared to traditional restoration procedures (Tiano et al., 1999). Castanier et al. (2000) found that Bacillus cereus was able to induce extracellular precipitation of calcium carbonate on decayed limestones. Rodriguez-Navarro et al. (2003) tested the ability of Myxococcus xanthus to induce calcium carbonate precipitation. Current studies are evaluating the potential of bacteria as self-healing agents for the autonomous decrease of permeability of concrete upon crack formation (De Muynck, et al 2010) In the urban area of Seville, most historical buildings are constructed with calcarenites, limestones, sandstones and bricks, the weathering forms associated to this building materials often are granular disintegration, so the proposed technology has a huge potential to be applied to these materials for possible restoration. This research is mainly grounded on laboratory work, which

  19. Postnatal changes in the expressions of serotonin 1A, 1B, and 2A receptors in ten brain stem nuclei of the rat: implication for a sensitive period

    PubMed Central

    Liu, Qiuli; Wong-Riley, Margaret T.T.

    2009-01-01

    A critical period in respiratory network development occurs in the rat around postnatal days (P)12–13, when abrupt neurochemical, metabolic, and physiological changes were evident. As serotonin (5-HT) and its receptors are involved in respiratory modulation, and serotonergic abnormality is implicated in Sudden Infant Death Syndrome, we hypothesized that 5-HT receptors are significantly down-regulated during the critical period. This was documented recently for 5-HT2AR in several respiratory nuclei. The present study represents a comprehensive analysis of postnatal development of 5-HT1AR and 5-HT1BR in ten brain stem nuclei and 5-HT2AR in six nuclei not previously examined. Optical densitometric analysis of immunohistochemically-reacted neurons from P2 to P21 indicated four developmental patterns of expression: 1) Pattern I: a high level of expression at P2–P11, an abrupt and significant reduction at P12, followed by a plateau until P21 (5-HT1AR and 5-HT1BR in raphé magnus [RM], raphé obscurus [ROb], raphé pallidus [RP], pre-Bötzinger complex [PBC], nucleus ambiguus [Amb], and hypoglossal nucleus [XII; 5-HT1AR only]). 2) Pattern II: a high level at P2–P9, a gradual decline from P9 to P12, followed by a plateau until P21 (5-HT1AR and 5-HT1BR in the retrotrapezoid nucleus [RTN]/parafacial respiratory group [pFRG]). 3) Pattern III: a high level at P2–P11, followed by a gradual decline until P21 (5-HT1AR in the ventrolateral subnucleus of solitary tract nucleus [NTSVL] and the non-respiratory cuneate nucleus [CN]). 4) Pattern IV: a relatively constant level maintained from P2 to P21 (5-HT1AR in the commissural subnucleus of solitary tract nucleus [NTSCOM]; 5-HT1BR in XII, NTSVL, NTSCOM, and CN; and 5-HT2AR in RM, ROb, RP, RTN/pFRG, NTSVL, and NTSCOM). Thus, a significant reduction in the expression of 5-HT1AR, 5-HT1BR, and 5-HT2AR in multiple respiratory-related nuclei at P12 is consistent with reduced serotonergic transmission during the critical period

  20. Injections of Algesic Solutions into Muscle Activate the Lateral Reticular Formation: A Nociceptive Relay of the Spinoreticulothalamic Tract

    PubMed Central

    Panneton, W. Michael; Gan, Qi; Ariel, Michael

    2015-01-01

    Although musculoskeletal pain disorders are common clinically, the central processing of muscle pain is little understood. The present study reports on central neurons activated by injections of algesic solutions into the gastrocnemius muscle of the rat, and their subsequent localization by c-Fos immunohistochemistry in the spinal cord and brainstem. An injection (300μl) of an algesic solution (6% hypertonic saline, pH 4.0 acetate buffer, or 0.05% capsaicin) was made into the gastrocnemius muscle and the distribution of immunolabeled neurons compared to that obtained after control injections of phosphate buffered saline [pH 7.0]. Most labeled neurons in the spinal cord were found in laminae IV-V, VI, VII and X, comparing favorably with other studies, with fewer labeled neurons in laminae I and II. This finding is consistent with the diffuse pain perception due to noxious stimuli to muscles mediated by sensory fibers to deep spinal neurons as compared to more restricted pain localization during noxious stimuli to skin mediated by sensory fibers to superficial laminae. Numerous neurons were immunolabeled in the brainstem, predominantly in the lateral reticular formation (LRF). Labeled neurons were found bilaterally in the caudalmost ventrolateral medulla, where neurons responsive to noxious stimulation of cutaneous and visceral structures lie. Immunolabeled neurons in the LRF continued rostrally and dorsally along the intermediate reticular nucleus in the medulla, including the subnucleus reticularis dorsalis caudally and the parvicellular reticular nucleus more rostrally, and through the pons medial and lateral to the motor trigeminal nucleus, including the subcoerulear network. Immunolabeled neurons, many of them catecholaminergic, were found bilaterally in the nucleus tractus solitarii, the gracile nucleus, the A1 area, the CVLM and RVLM, the superior salivatory nucleus, the nucleus locus coeruleus, the A5 area, and the nucleus raphe magnus in the pons. The

  1. Finishing high school: alternative pathways and dropout recovery.

    PubMed

    Tyler, John H; Lofstrom, Magnus

    2009-01-01

    John Tyler and Magnus Lofstrom take a close look at the problems posed when students do not complete high school. The authors begin by discussing the ongoing, sometimes heated, debate over how prevalent the dropout problem is. They note that one important reason for discrepancies in reported dropout rates is whether holders of the General Educational Development (GED) credential are counted as high school graduates. The authors also consider the availability of appropriate student data. The overall national dropout rate appears to be between 22 and 25 percent, but the rate is higher among black and Hispanic students, and it has not changed much in recent decades. Tyler and Lofstrom conclude that schools are apparently doing about as well now as they were forty years ago in terms of graduating students. But the increasingly competitive pressures associated with a global economy make education ever more important in determining personal and national well-being. A student's decision to drop out of school, say the authors, is affected by a number of complex factors and is often the culmination of a long process of disengagement from school. That decision, not surprisingly, carries great cost to both the student and society. Individual costs include lower earnings, higher likelihood of unemployment, and greater likelihood of health problems. Because minority and low-income students are significantly more likely than well-to-do white students to drop out of school, the individual costs fall unevenly across groups. Societal costs include loss of tax revenue, higher spending on public assistance, and higher crime rates. Tyler and Lofstrom go on to survey research on programs designed to reduce the chances of students' dropping out. Although the research base on this question is not strong, they say, close mentoring and monitoring of students appear to be critical components of successful programs. Other dropout-prevention approaches associated with success are family

  2. Scattering resonance of elastic wave and low-frequency equivalent slow wave

    NASA Astrophysics Data System (ADS)

    Meng, X.; Liu, H.; Hu, T.; Yang, L.

    2015-12-01

    Transmitted wave occurs as fast p-wave and slow p-wave in certain conditions when seismic waves travel through inhomogeneous layers. Energy of slow p-waves is strongest at some frequency band, but rather weak at both high frequency band and low frequency band, called scattering resonance. For practical seismic exploration, the frequency of slow p-wave occurs is below 10Hz, which cannot be explained by Biot's theory which predicts existence of the slow p-wave at ultrasonic band in the porous media. The slow p-wave equation have been derived, but which only adapted to explaining slow p-wave in the ultrasonic band. Experimental observations exhibit that slow p-wave also exists in nonporous media but with enormous low-velocity interbeds. When vertical incidence, elastic wave is simplified as compressing wave, the generation of slow waves is independent on shear wave. In the case of flat interbed and gas bubble, Liu (2006) has studied the transmission of acoustic waves, and found that the slow waves below the 10Hz frequency band can be explained. In the case of general elastic anisotropy medium, the tiheoretical research on the generation of slow waves is insufficient. Aiming at this problem, this paper presents an exponential mapping method based on transmitted wave (Magnus 1954), which can successfully explain the generation of the slow wave transmission in that case. Using the prediction operator (Claerbout 1985) to represent the transmission wave, this can be derived as first order partial differential equation. Using expansions in the frequency domain and the wave number domain, we find that the solutions have different expressions in the case of weak scattering and strong scattering. Besides, the method of combining the prediction operator and the exponential map is needed to extend to the elastic wave equation. Using the equation (Frazer and Fryer 1984, 1987), we derive the exponential mapping solution for the prediction operator of the general elastic medium

  3. The effect of spin in swing bowling in cricket: model trajectories for spin alone

    NASA Astrophysics Data System (ADS)

    Robinson, Garry; Robinson, Ian

    2015-02-01

    In ‘swing’ bowling, as employed by fast and fast-medium bowlers in cricket, back-spin along the line of the seam is normally applied in order to keep the seam vertical and to provide stability against ‘wobble’ of the seam. Whilst spin is normally thought of as primarily being the slow bowler's domain, the spin applied by the swing bowler has the side-effect of generating a lift or Magnus force. This force, depending on the orientation of the seam and hence that of the back-spin, can have a side-ways component as well as the expected vertical ‘lift’ component. The effect of the spin itself, in influencing the trajectory of the fast bowler's delivery, is normally not considered, presumably being thought of as negligible. The purpose of this paper is to investigate, using calculated model trajectories, the amount of side-ways movement due to the spin and to see how this predicted movement compares with the total observed side-ways movement. The size of the vertical lift component is also estimated. It is found that, although the spin is an essential part of the successful swing bowler's delivery, the amount of side-ways movement due to the spin itself amounts to a few centimetres or so, and is therefore small, but perhaps not negligible, compared to the total amount of side-ways movement observed. The spin does, however, provide a considerable amount of lift compared to the equivalent delivery bowled without spin, altering the point of pitching by up to 3 m, a very large amount indeed. Thus, for example, bowling a ball with the seam pointing directly down the pitch and not designed to swing side-ways at all, but with the amount of back-spin varied, could provide a very powerful additional weapon in the fast bowler's arsenal. So-called ‘sling bowlers’, who use a very low arm action, can take advantage of spin since effectively they can apply side-spin to the ball, giving rise to a large side-ways movement, ˜ 20{}^\\circ cm or more, which certainly is

  4. Modeling and Simulation of the Dynamics of Dissipative, Inelastic Spheres with Applications to Planetary Rovers and Gravitational Billiards

    NASA Astrophysics Data System (ADS)

    Hartl, Alexandre E.

    This dissertation provides a thorough treatment on the dynamic modeling and simulation of spherical objects, and its applications to planetary rovers and gravitational billiards. First, the equations governing the motion of a wind-driven spherical rover are developed, and a numerical procedure for their implementation is shown. Dynamic simulations (considering the Earth and Mars atmospheres) for several terrain types and conditions illustrate how a rover may maneuver across flat terrain, channels and craters. The effects of aerodynamic forces on the rover's motion is studied. The results show the wind force may both push and hinder the rover's motion while sliding, rolling and bouncing. The rover will periodically transition between these modes of movement when the rover impacts sloped surfaces. Combinations of rolling and bouncing may be a more effective means of transport for a rover traveling through a channel when compared to rolling alone. The aerodynamic effects, of drag and the Magnus force, are contributing factors to the possible capture of the rover by a crater. Next, a strategy is formulated for creating randomized Martian rock fields based on statistical models, where the rover's interactions with these fields are analyzed. Novel procedures for creating randomized Martian rock fields are presented, where optimization techniques allow terrain generation to coincide with the rover's motion. Efficient collision detection routines reduce the number of tests of potential collisions between the rover and the terrain while establishing new contact constraints. The procedures allow for the exploration of large regions of terrain while minimizing computational costs. Simulations demonstrate that bouncing is the rover's dominant mode of travel through the rock fields. Monte-Carlo simulations illustrate how the rover's down-range position depends on the rover design and atmospheric conditions. Moreover, the simulations verify the rover's capacity for long distance

  5. Heat Transfer in Boiling Dilute Emulsion with Strong Buoyancy

    NASA Astrophysics Data System (ADS)

    Freeburg, Eric Thomas

    Little attention has been given to the boiling of emulsions compared to that of boiling in pure liquids. The advantages of using emulsions as a heat transfer agent were first discovered in the 1970s and several interesting features have since been studied by few researchers. Early research focuses primarily on pool and flow boiling and looks to determine a mechanism by which the boiling process occurs. This thesis looks at the boiling of dilute emulsions in fluids with strong buoyant forces. The boiling of dilute emulsions presents many favorable characteristics that make it an ideal agent for heat transfer. High heat flux electronics, such as those seen in avionics equipment, produce high heat fluxes of 100 W/cm2 or more, but must be maintained at low temperatures. So far, research on single phase convection and flow boiling in small diameter channels have yet to provide an adequate solution. Emulsions allow the engineer to tailor the solution to the specific problem. The fluid can be customized to retain the high thermal conductivity and specific heat capacity of the continuous phase while enhancing the heat transfer coefficient through boiling of the dispersed phase component. Heat transfer experiments were carried out with FC-72 in water emulsions. FC-72 has a saturation temperature of 56 °C, far below that of water. The parameters were varied as follows: 0% ≤ epsilon ≤ 1% and 1.82 x 1012 ≤ RaH ≤ 4.42 x 1012. Surface temperatures along the heated surface reached temperature that were 20 °C in excess of the dispersed phase saturation temperature. An increase of ˜20% was seen in the average Nusselt numbers at the highest Rayleigh numbers. Holography was used to obtain images of individual and multiple FC-72 droplets in the boundary layer next to the heated surface. The droplet diameters ranged from 0.5 mm to 1.3 mm. The Magnus effect was observed when larger individual droplets were injected into the boundary layer, causing the droplets to be pushed

  6. “Target” and “Sandwich” Signs in Thigh Muscles have High Diagnostic Values for Collagen VI-related Myopathies

    PubMed Central

    Fu, Jun; Zheng, Yi-Ming; Jin, Su-Qin; Yi, Jun-Fei; Liu, Xiu-Juan; Lyn, He; Wang, Zhao-Xia; Zhang, Wei; Xiao, Jiang-Xi; Yuan, Yun

    2016-01-01

    Background: Collagen VI-related myopathies are autosomal dominant and recessive hereditary myopathies, mainly including Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). Muscle magnetic resonance imaging (MRI) has been widely used to diagnosis muscular disorders. The purpose of this study was to evaluate the diagnostic value of thigh muscles MRI for collagen VI-related myopathies. Methods: Eleven patients with collagen VI gene mutation-related myopathies were enrolled in this study. MRI of the thigh muscles was performed in all patients with collagen VI gene mutation-related myopathies and in 361 patients with other neuromuscular disorders (disease controls). T1-weighted images were used to assess fatty infiltration of the muscles using a modified Mercuri's scale. We assessed the sensitivity and specificity of the MRI features of collagen VI-related myopathies. The relationship between fatty infiltration of muscles and specific collagen VI gene mutations was also investigated. Results: Eleven patients with collagen VI gene mutation-related myopathies included six UCMD patients and five BM patients. There was no significant difference between UCMD and BM patients in the fatty infiltration of each thigh muscle except sartorius (P = 0.033); therefore, we combined the UCMD and BM data. Mean fatty infiltration scores were 3.1 and 3.0 in adductor magnus and gluteus maximus, while the scores were 1.3, 1.3, and 1.5 in gracilis, adductor longus, and sartorius, respectively. A “target” sign in rectus femoris (RF) was present in seven cases, and a “sandwich” sign in vastus lateralis (VL) was present in ten cases. The “target” and “sandwich” signs had sensitivities of 63.6% and 90.9% and specificities of 97.3% and 96.9% for the diagnosis of collagen VI-related myopathies, respectively. Fatty infiltration scores were 2.0–3.0 in seven patients with mutations in the triple-helical domain, and 1.0–1.5 in three of four patients with

  7. The complete mitochondrial genome of the house dust mite Dermatophagoides pteronyssinus (Trouessart): a novel gene arrangement among arthropods

    PubMed Central

    Dermauw, Wannes; Van Leeuwen, Thomas; Vanholme, Bartel; Tirry, Luc

    2009-01-01

    Background The apparent scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). This subclass encompasses over 48,000 species and forms the largest group within the Arachnida. Although mitochondrial genomes are widely utilised for phylogenetic and population genetic studies, only 20 mitochondrial genomes of Acari have been determined, of which only one belongs to the diverse order of the Sarcoptiformes. In this study, we describe the mitochondrial genome of the European house dust mite Dermatophagoides pteronyssinus, the most important member of this largely neglected group. Results The mitochondrial genome of D. pteronyssinus is a circular DNA molecule of 14,203 bp. It contains the complete set of 37 genes (13 protein coding genes, 2 rRNA genes and 22 tRNA genes), usually present in metazoan mitochondrial genomes. The mitochondrial gene order differs considerably from that of other Acari mitochondrial genomes. Compared to the mitochondrial genome of Limulus polyphemus, considered as the ancestral arthropod pattern, only 11 of the 38 gene boundaries are conserved. The majority strand has a 72.6% AT-content but a GC-skew of 0.194. This skew is the reverse of that normally observed for typical animal mitochondrial genomes. A microsatellite was detected in a large non-coding region (286 bp), which probably functions as the control region. Almost all tRNA genes lack a T-arm, provoking the formation of canonical cloverleaf tRNA-structures, and both rRNA genes are considerably reduced in size. Finally, the genomic sequence was used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analysis clustered D. pteronyssinus with Steganacarus magnus, forming a sistergroup of the Trombidiformes. Conclusion Although the mitochondrial genome of D. pteronyssinus shares different features with previously characterised Acari mitochondrial genomes, it is unique in many ways. Gene order is extremely rearranged

  8. Changes in thalamic nociception resulting from morphine- and meperidine-dependence in rats.

    PubMed

    Emmers, R

    1984-01-01

    neural pathway that descends from the periaqueductal gray matter via the nucleus raphe magnus to the spinal cord and there blocks the excitation of the spinothalamic tract cells by A-delta and C fibers. The mechanisms that increase the spontaneous activity of the thalamic nociceptive neurons remain unclear. PMID:6537810

  9. Transient configurations of baroresponsive respiratory-related brainstem neuronal assemblies in the cat

    PubMed Central

    Arata, A; Hernandez, Y M; Lindsey, B G; Morris, K F; Shannon, R

    2000-01-01

    The regulation of gas exchange requires coordination of the respiratory and cardiovascular systems. Previous work suggested that medullary raphe neurones transform and transmit information from baroreceptors to neurones in the ventral respiratory group. This study tested the hypothesis that distributed brainstem neuronal assemblies are transiently reconfigured during the respiratory cycle and baroreceptor stimulation. Blood pressure was perturbed by intravenous injection of an α1-adrenergic receptor agonist, unilateral pressure changes in the carotid sinus, or occlusion of the descending aorta in 14 Dial-urethane anaesthetized, vagotomized, paralysed, artificially ventilated cats. Neurones were monitored simultaneously with microelectrode arrays in two or more of the following sites: n. raphe obscurus, n. raphe magnus, rostral and caudal ventrolateral medulla, and the nucleus tractus solitarii. Transient configurations of baroresponsive assemblies were detected with joint pericycle-triggered histograms, the gravitational representation, and related pattern detection methods. Data were also analysed with cycle-triggered histograms, peristimulus-time and cumulative sum histograms, cross-correlograms, spike-triggered averages of efferent phrenic activity, and joint impulse configuration scatter diagrams (snowflakes). Five to nine simultaneously recorded spike trains from control expiratory phases were compared with data from interleaved equal-duration time blocks from control inspiratory phases. In each of seven animals, significant impulse synchrony detected by gravity analysis was confined to one phase of the respiratory cycle. Repeated patterns of distributed synchrony confined to periods of altered baroreceptor activity were detected and involved neurones that individually did not change firing rates during stimulation. Snowflakes and logical cross-correlation analysis provided evidence for the cooperative actions of impulses in concurrently active parallel

  10. Genetic analysis of the response to eleven Colletotrichum lindemuthianum races in a RIL population of common bean (Phaseolus vulgaris L.)

    PubMed Central

    2014-01-01

    Background Bean anthracnose is caused by the fungus Colletotrichum lindemuthianum (Sacc. & Magnus) Lams.- Scrib. Resistance to C. lindemuthianum in common bean (Phaseolus vulgaris L.) generally follows a qualitative mode of inheritance. The pathogen shows extensive pathogenic variation and up to 20 anthracnose resistance loci (named Co-), conferring resistance to specific races, have been described. Anthracnose resistance has generally been investigated by analyzing a limited number of isolates or races in segregating populations. In this work, we analyzed the response against eleven C. lindemuthianum races in a recombinant inbred line (RIL) common bean population derived from the cross Xana × Cornell 49242 in which a saturated linkage map was previously developed. Results A systematic genetic analysis was carried out to dissect the complex resistance segregations observed, which included contingency analyses, subpopulations and genetic mapping. Twenty two resistance genes were identified, some with a complementary mode of action. The Cornell 49242 genotype carries a complex cluster of resistance genes at the end of linkage group (LG) Pv11 corresponding to the previously described anthracnose resistance cluster Co-2. In this position, specific resistance genes to races 3, 6, 7, 19, 38, 39, 65, 357, 449 and 453 were identified, with one of them showing a complementary mode of action. In addition, Cornell 49242 had an independent gene on LG Pv09 showing a complementary mode of action for resistance to race 453. Resistance genes in genotype Xana were located on three regions involving LGs Pv01, Pv02 and Pv04. All resistance genes identified in Xana showed a complementary mode of action, except for two controlling resistance to races 65 and 73 located on LG Pv01, in the position of the previously described anthracnose resistance cluster Co-1. Conclusions Results shown herein reveal a complex and specific interaction between bean and fungus genotypes leading to

  11. PREFACE: 2nd Russia-Japan-USA Symposium on the Fundamental and Applied Problems of Terahertz Devices and Technologies (RJUS TeraTech - 2013)

    NASA Astrophysics Data System (ADS)

    Karasik, Valeriy; Ryzhii, Viktor; Yurchenko, Stanislav

    2014-03-01

    Kirova, University Paris-Sud, France Andrei Sergeev, Department of Electrical Engineering, The University of Buffalo, The State University of New Your, Buffalo, NY, USA Magnus Willander, Linkoping University (LIU), Department of Science and Technology, Linkopings, Sweden Dmitry R Khohlov, Physical Faculty, Lomonosov Moscow State University, Russia Vladimir L Vaks, Institute for Physics of Microstructures of Russian Academy of Sciences, Russia

  12. [Bernard Schapiro--an orthodox Jew as an early andrologist in the 20th century].

    PubMed

    Borgwardt, Götz

    2002-01-01

    The unusual history and professional background of one of the first andrologists is reported. Bernhard Schapiro, born in 1888 in Dvinsk in Latvia, then a city in the Russian Pale of Settlements for Jews, grew up as an orthodox (hassidic) Jew receiving exclusively talmudic lessons until he was 18 years old. During the final years of this period of life he was educated at the famous Slobodka Talmud Academy Kenesset Israel in Kovno where he absorbed the ideals of Musar-doctrines, thus being influenced for the rest of his life. The Rogachover Gaon J. Rozin supported his desire to study medicine. After a brief stay in Frankfurt/Main he acquired by own efforts the necessary general knowledge to matriculate for access to university. Medical studies at Zurich University (1913-1919) were followed by a one-year-internship at a dermatologic department in Breslau/Silesia. The thesis for his doctorate at Zurich University in 1920 was on, Relations between Nodular Erythema and Tuberculosis'. He spent two years training in dermatology at Breslau University under Jadassohn. Back in Berlin, he married and had four children, while he worked at Magnus Hirschfeld's Institute for Sexual Sciences. After initial clinical studies in venerology he more and more turned to andrological problems, including treatment of underdeveloped male genitals, premature ejaculation and impotence in general. In this context he tested the new drug Praehormon and developed the two remedies Testifortan and Praejaculin. He was the first to describe the effect of anterior pituitary lobe hormone on the descent of cryptorchid testicles, thus initiating a treatment modality still in motion today. When Hitler came to power he and his family were spared as Swiss citizens, but he lost his base for working after the Institute was looted. He established an andrologic practice at Zurich. What he had witnessed in Germany caused him to set up a Swiss branch of Mizrachi, the spiritually based center of Zionism in

  13. Morphological and quantitative comparison between infectious and non-infectious forms of influenza virus.

    PubMed

    WERNER, G H; SCHLESINGER, R W

    1954-08-01

    Electron microscopic study has revealed the morphological entity responsible for the rise in viral hemagglutinin observed in brains of mice after intracerebral inoculation of non-neurotropic strains of influenza virus. This rise in hemagglutinin, although dependent on inoculation of fully infectious virus, is not associated with an increase in infectious titer. The hemagglutinating principle is functionally similar to the "incomplete" influenza virus which can be obtained from chick embryos by serial egg-to-egg transfer of undiluted, infected allantoic fluid according to the method of von Magnus. A method has been described which facilitates selective adsorption of viral particles recovered from organ extracts on saponine-lysed ghosts of fowl erythrocytes. This procedure has been utilized in studying the morphology of non-infectious, hemagglutinating virus from chorio-allantoic membranes or mouse brains and in comparing these two forms with each other and with ordinary, infectious (standard) influenza virus. Standard virus isolated from allantoic fluids or membranes of infected eggs was found to contain uniform particles of predominantly spherical shape with smooth surface and even density, resembling those described by others. The appearance of such particles was not affected by the procedure of extraction and concentration used. In contrast, non-infectious, hemagglutinating virus obtained either from allantoic sacs ("undiluted passages") or from mouse brain was pleomorphic and seemed to consist of disintegrating particles. The majority appeared flattened and bag-like and had a rough, granular surface and reduced, uneven density. 37 per cent of the non-infectious particles isolated from mouse brain infected with the non-neurotropic strain WS had diameters in excess of 170 mmicro, as compared with only 2 per cent of the particles of the parent strain itself. Regardless of whether or not the contrast in appearance of standard and of non-infectious particles was due

  14. A second-order accurate immersed boundary-lattice Boltzmann method for particle-laden flows

    NASA Astrophysics Data System (ADS)

    Zhou, Qiang; Fan, Liang-Shih

    2014-07-01

    A new immersed boundary-lattice Boltzmann method (IB-LBM) is presented for fully resolved simulations of incompressible viscous flows laden with rigid particles. The immersed boundary method (IBM) recently developed by Breugem (2012) [19] is adopted in the present method, development including the retraction technique, the multi-direct forcing method and the direct account of the inertia of the fluid contained within the particles. The present IB-LBM is, however, formulated with further improvement with the implementation of the high-order Runge-Kutta schemes in the coupled fluid-particle interaction. The major challenge to implement high-order Runge-Kutta schemes in the LBM is that the flow information such as density and velocity cannot be directly obtained at a fractional time step from the LBM since the LBM only provides the flow information at an integer time step. This challenge can be, however, overcome as given in the present IB-LBM by extrapolating the flow field around particles from the known flow field at the previous integer time step. The newly calculated fluid-particle interactions from the previous fractional time steps of the current integer time step are also accounted for in the extrapolation. The IB-LBM with high-order Runge-Kutta schemes developed in this study is validated by several benchmark applications. It is demonstrated, for the first time, that the IB-LBM has the capacity to resolve the translational and rotational motion of particles with the second-order accuracy. The optimal retraction distances for spheres and tubes that help the method achieve the second-order accuracy are found to be around 0.30 and -0.47 times of the lattice spacing, respectively. Simulations of the Stokes flow through a simple cubic lattice of rotational spheres indicate that the lift force produced by the Magnus effect can be very significant in view of the magnitude of the drag force when the practical rotating speed of the spheres is encountered. This finding

  15. A Grazing Encounter Between Two Spiral Galaxies

    NASA Technical Reports Server (NTRS)

    1999-01-01

    sets were obtained by Debra Meloy Elmegreen (Vassar College), Bruce G. Elmegreen (IBM Research Division), Michele Kaufman (Ohio State U.), Elias Brinks (Universidad de Guanajuato, Mexico), Curt Struck (Iowa State University), Magnus Thomasson (Onsala Space Obs., Sweden), Maria Sundin (Goteborg University, Sweden), and Mario Klaric (Columbia, South Carolina).

  16. The history of British gynaecological pathology.

    PubMed

    Young, Robert H

    2009-01-01

    for the acceptance in Britain of the concepts of trophoblastic disease espoused by the German investigator Felix Marchand. Wallace Park of Dundee also contributed significantly on trophoblastic disease in later years. The years following the death of Dr Teacher were largely dominated by three individuals, Magnus Haines working in London, Claud Taylor in Birmingham, and Frederick Langley in Manchester. The first two individuals wrote an excellent textbook and Langley brought great fame to the Manchester School, ably assisted by Harold Fox, the latter being the doyen of British gynaecologic pathologists throughout the latter decades of the 20th century. With Langley he wrote an important book on ovarian tumours, an equally influential book on the placenta, and with Dr Hilary Buckley he authored a book on endometrial biopsy interpretation. Additionally, his countless entertaining and instructive lectures throughout the world represented a remarkable educational experience. PMID:19207941

  17. North Pole, South Pole: the quest to understand the mystery of Earth's magnetism

    NASA Astrophysics Data System (ADS)

    Turner, G. M.

    2010-12-01

    The story of the quest to understand Earth’s magnetic field is one of the longest and richest in the history of science. It weaves together Greek philosophy, Chinese mysticism, the development of the compass and navigation, the physics of electromagnetism and the jig-saw like piecing together of the internal structure of the planet beneath our feet. The story begins with Magnes, an old shepherd, trudging up the mountainside after a violent thunder storm, astonished at how the iron studs in his boots stick to the rocks. It was Alexander von Humboldt who, three millennia on, pointed to lightning as the source of such magnetization. The first compass was made 2000 years ago in China - to divine the ways of feng shui - a guide to planting crops, planning streets, orienting buildings and more. It reached Europe as a navigational tool in the 12th century - no-one is quite sure how, but en route it changed from south-pointing to the north-pointing compasses of today. The earliest truly scientific experiments and writings concerned magnets and geomagnetism: Petrus Peregrinus’ Epistola of 1269, and William Gilbert’s De Magnete of1600, in which he declared Magnus magnes globus terrestris ipse est - the Earth itself is a great magnet. By then it was recognized that the compass didn’t point exactly north, and the discrepancy varied from place to place and changed over time - something of a problem for Gilbert’s idea of a geocentric axial dipole. However declination and secular variation were problems well known to Edmund Halley, who, in 1700, charted the angle of declination over the Atlantic Ocean, and in the process introduced the Halleyan line - the contour. Many of the world’s greatest scientists have turned their minds to the problem of magnetism and geomagnetism in particular - Coulomb, Gauss, Faraday, Maxwell - yet in 1905, Einstein described geomagnetism as “one of the great unsolved problems of physics”. In the mid-late nineteenth century new areas of

  18. Topics in mathematical physics, general relativity, and cosmology in honor of Jerzy Plebanski

    NASA Astrophysics Data System (ADS)

    Plebanski, Jerzy; Garcia-Compean, Hugo

    . Maldacena. Yang-Mills type BRST and co-BRST algebra for Teleparallelism / E. W. Mielke & A. A. Rincon Maggiolo. The double role of Einstein's equations: as equations of motion and as vanishing energy-momentum tensor / M. Montesinos. Alternative elements in the Cayley-Dickson algebras / G. Moreno. Coherent state map and deformations of Moyal product / A. Odzijewicz. On uncertainty relations and states in deformation quantization / M. Przanowski & F. J. Turrubiates. On the Dirac-Infeld-Plebanski delta function / O. Rosas-Ortiz. Mathematical structures in perturbation quantum field theory / M. Rosenbaum. A note on the foundation of relativistic mechanics: covariant Hamiltonian general relativity / C. Rovelli. The Magnus series / L. Saenz & R. Suarez. Singular integral equation method for the construction of cylindrical wave solutions of the Einstein-Weyl equations / N. R. Sibgatullin, A. A. Garcia & V. S. Manko. Geometric POV-measures, pseudo-Kahlerian functions and time / M. Skulimowski. Teleparallelism, modified Born-Infeld nonlinearity and space-time as a micromorphic ether / J. J. Slawianowski. Einstein's intuition and the post-Newtonian approximation / J. Stachel. Deformation theory and physics model building / D. Sternheimer. Lanczos potentials via the HH formalism / G. F. Torres del Castillo. Spin foam model for 3D gravity in the continuum / J. A. Zapata -- pt. III. Informal part. Ecology of the Riemann tensor / B. Mielnik. Poem to Prof. Dr. Jerzy F. Plebanski / N. V. Mitskievich (Mickiewicz).

  19. Efficiency of preventive actions for landslides and flooding - evaluation of Scandinavian practices

    NASA Astrophysics Data System (ADS)

    Bergman, R.; Andersson-sköld, Y. B.; Nyberg, L.; Johansson, M.; Persson, E.

    2011-12-01

    Author: Ramona Bergman, Yvonne Andersson-Sköld, Lars Nyberg, Magnus Johansson, Erik Persson Preventive actions can be, and are frequently, taken to reduce accidents and their consequences in different ways. The MSB funded research programme "Effects of Society's Security actions" (ESS, 2009-2013) aims to study the relationship between such actions and their effects. The program is divided into three subgroups: Frequent accidents Natural hazards (such as flooding, erosion and landslide) Chemical and landfill accidents The results presented here covers natural hazards with focus on land slides and flooding. The results are based on Swedish/Scandinavian contexts. Natural events such as erosion, flooding and land slides are common, but the number of accidents (events causing severe negative impact) is rare. Therefore, in such analysis there is limited data and other information available which can be used for example in statistical analysis of actions and their effects. Instead, the analysis must be based on other information. Therefore, the analysis may have to include aspects that only can be assessed by scenario and "what-if" analyses. In this project the main method has been interviews with officials in Swedish municipalities and national agencies in Sweden and Norway. The two levels are chosen since policies are taken on national (or international) level, while the key actions and actors are on the municipal level. The interviews cover experiences and potential scenarios. In all municipalities, one politician and officials working with planning and rescue service have been interviewed. The study covers hazard and risk mapping, follow up of such maps, physical planning and lessons learned from previous events and activities. The final outcome of the research will be a review of what is found to be well functioning, identification of weak points and recommendations for the management of landslides, erosion and flooding. The present results indicate that hazard

  20. [Epilepsy, eponyms and patron saints (history of Western civilization)].

    PubMed

    Janković, S M; Sokić, D V; Lević, Z M; Susić, V; Stojsavljević, N; Drulović, J

    1996-01-01

    about the precipitous decay of attitudes that started with Romans and inaugurated the way of thinking characteristic of Renaissance and the ages thereafter. Serbian literature of the Middle Age was strongly impacted by influences that fanned from Italy (Salerno) and south France (Montpellier), reflecting the attitudes of medical schools and universities prevailing at that time Europe. The name [symbol: see text] from Hilandar Medical Codex No 517 (XV-XVI century) is obviously taken from Byzantine medicine, which was founded on the works of Hippocrates, Galen and Dioscurides. It came down to us through the Serbian folk Byzantine codices named "latrosophia of Hilandar", preserved mostly from the author Michail Pselos (XI century). On the other hand, the name [symbol: see text] or morbus magnus, reflects its Roman origin. The name [symbol: see text] meaning fainting, loss of consciousness or syncope, stems from the same source. The name [symbol: see text] designated epileptic disease in Serbian monks, monasteries probably being the only niche where epileptics could find refuge. Children's epilepsy or convulsions are expressed as [symbol: see text] No mention is found of epileptic status except for the notion [symbol: see text] meaning "to be without consciousness for a longer period of time'; it does not, however, refer directly to epilepsy or convulsions. It is worthy noting that already in the XIV century Serbs had their medical literature translated to their own language, and were the only one of all Slavic peoples that did so. Nevertheless, both apocryphal and canonical, as well as consecrated medicine were based on magic, astrology and occultism. The magic formulas used in Middle Age Serbia for the cure of epileptics as well as sick in general, were basically irrational; still, as a trace of its descension they contained unintelligible words of the eastern origin (Greek, Persian or Jewish). (ABSTRACT TRUNCATED) PMID:9102840

  1. Euophryine jumping spiders of the Afrotropical Region-new taxa and a checklist (Araneae: Salticidae: Euophryinae).

    PubMed

    Wesołowska, Wanda; Azarkina, Galina N; Russell-Smith, Anthony

    2014-01-01

    ), Rumburak laxus (Zhang & Maddison, 2012) (ex Thyenula) and Thyenula munda (Peckham & Peckham, 1903) (ex Saitis). Two names are recognized as nomina dubia: Euophrys nigrescens Caporiacco, 1940 and Saitis magnus Caporiacco, 1947. The first member of the genus Chinophrys Zhang & Maddison, 2012 is reported from Africa. The males of Euophrys leipoldti Peckham & Peckham, 1903 and Thyenula sempiterna Wesołowska, 2000 are described for the first time. Tanzania minutus (Wesołowska & Russell-Smith, 2000) is recorded from South Africa for the first time. A list of valid species of Afrotropical Euophryinae with data on their distribution in the region is provided. A key is supplied for the known genera of the region (based on males).  PMID:24869747

  2. The early fluidic and optical physics of cytometry.

    PubMed

    Watson, J V

    1999-02-15

    All forms of cytometry, depend on the basic laws of physics, including those of fluidics, optics, and electronics, most of which were established centuries ago. Flow cytometry depends critically on the fluidics presenting each individual cell with precision to the sensing volume. This is intersected by a high-intensity light source, and light scattering and fluorescence from suitably stained constituents in each cell are captured by the light-collecting optics and measured. The works and observations of Bernoulli and Euler in the 18th century, Reynolds in the 19th century, and Crosland-Taylor in the 20th century in the field of fluid dynamics laid the foundations for hydrodynamic focussing, which is the primary prerequisite for presenting individual cells to the sensing volume. In addition, electrostatic cell sorters must have the ability to generate stable droplet formation in the jet-stream issuing from the flow chamber nozzle. The origins here can be traced to work carried out in the early to mid-19th century by Savart, Magnus, and Thomson. Flow, image, and confocal cytometry are all dependent on the laws of optics, including those of reflection and refraction as well as numerous other optical principles. The observations and works of Socrates, Ptolemy, Snel, and Descartes between about BC 370 and 1637 were of seminal importance in developing the laws of reflection and refraction. In the mid-17th century Hooke illustrated the power of magnifying glasses and microscopy in his Micrographia and Newton was responsible for explaining colours in the spectrum. Huygens, toward the end of the 17th century, put forward the concept of point source light propagation contributing to a wave front. Finally, Thomas Young, early in the 19th century, established the wave form of light from interference patterns. Most people will be familiar with some of these discoveries and the investigators who carried out the work; some people will be familiar with all of these. However, very

  3. A second-order accurate immersed boundary-lattice Boltzmann method for particle-laden flows

    SciTech Connect

    Zhou, Qiang; Fan, Liang-Shih

    2014-07-01

    A new immersed boundary-lattice Boltzmann method (IB-LBM) is presented for fully resolved simulations of incompressible viscous flows laden with rigid particles. The immersed boundary method (IBM) recently developed by Breugem (2012) [19] is adopted in the present method, development including the retraction technique, the multi-direct forcing method and the direct account of the inertia of the fluid contained within the particles. The present IB-LBM is, however, formulated with further improvement with the implementation of the high-order Runge–Kutta schemes in the coupled fluid–particle interaction. The major challenge to implement high-order Runge–Kutta schemes in the LBM is that the flow information such as density and velocity cannot be directly obtained at a fractional time step from the LBM since the LBM only provides the flow information at an integer time step. This challenge can be, however, overcome as given in the present IB-LBM by extrapolating the flow field around particles from the known flow field at the previous integer time step. The newly calculated fluid–particle interactions from the previous fractional time steps of the current integer time step are also accounted for in the extrapolation. The IB-LBM with high-order Runge–Kutta schemes developed in this study is validated by several benchmark applications. It is demonstrated, for the first time, that the IB-LBM has the capacity to resolve the translational and rotational motion of particles with the second-order accuracy. The optimal retraction distances for spheres and tubes that help the method achieve the second-order accuracy are found to be around 0.30 and −0.47 times of the lattice spacing, respectively. Simulations of the Stokes flow through a simple cubic lattice of rotational spheres indicate that the lift force produced by the Magnus effect can be very significant in view of the magnitude of the drag force when the practical rotating speed of the spheres is encountered

  4. [The modulation of cerebral cortex and subcortical nuclei on NRM and their role in acupuncture analgesia].

    PubMed

    Liu, X

    1996-01-01

    The vast research have demonstrated that the acupuncture analgesia is effected through a physiological mechanism brought about by the nervous system, particularly the central nervous system. We combined the acupuncture effects and theory of channels and collaterals with the new advance of pain neurophysiology, and centred attention on nucleus raphe magnus (NRM), that is one of the origins of the important descending inhibitory pathways of the intrinsic analgesic systems in brain. The unit discharges of NRM neurons and their nociceptors/ph responses were recorded extracellularly with glass microelectrode at 1495 neurons on 634 wastar rats. The modulation of cerebral cortex, the head of N. caudatum (NCa), N. Accumbens (N. Ac), N lateral habenular (NHa) and Periaquaeductal gray matter (PAG) on NRM and their role in acupuncture analgesia were studied by central locational stimulation, lesion and microinjection. The result were as follows: 1. The most NRM neurons could respond to noxious stimulation of tail tip with increasing or decreasing firing rate. Electroacupuncture (EA) at "Zusanli" could activate the NRM neuron, increasing discharges, and inhibit their nociceptive responses, producing analgesia. 2. The activity of NRM neuron was modulated by PAG, NAc, and NCa. Stimulation at one of them can activate neuron of NRM, increasing firing rate, and induce analgesia. When the lesion or microinjection naloxone were made in PAG, NAc or NCa, EA analgesia could be weakened or lost, even the nociceptive responses might be increased. It is suggest that the nuclei participated in EA analgesia with their endogenous opiate like substance, and were playing an important role. It is also indicated that the electroacupuncture was used on the patients with some nuclei lesion or pathological changes should be careful to avoid making patients feel more painful. 3. Somatosensory area II (Sm II) of cerebral cortex participated in EA analgesia. The analgesic effects of EA at "Zusanli

  5. "Modified Adductor Sling Technique"- a surgical therapy for patellar instability in children and adolescents

    PubMed Central

    Alm, Lena; Frosch, Karl-Heinz; Preiss, Achim; Heitmann, Maximilian; Akoto, Ralph

    2016-01-01

    Aims and Objectives: Due to open femoral physis, the therapy of patellar instability in children and adolescents is challenging. We developed a surgical technique, modified form of the "Adductor-Sling-Technique" by Sillanpää which offers a surgical treatment to avoid damage to the femoral physis. The purpose of this study is to determine whether there is a benefit in the clinical outcome for patients operated by the "modified Adductor Sling Technique" in comparison to patients with other surgical procedures. Materials and Methods: Twenty "modified Adductor Sling" reconstructions in 19 patients (age 11-24) were included in the study until now, 15 patients with open physis and 4 patients with closed physis with special indications. Since 2010 "modified Adductor Sling" reconstruction was performed by looping the gracilis tendon around the adductor magnus tendon and attaching it at the medial facette of the patella. Clinical outcome was retrospectively evaluated at a mean follow-up period of 1.3 years (range 0.5-3.6). The evaluation also included Lysholm Score, Kujala Score and DGU score. Statistical analysis was performed using IBM®SPSS®Statistics Version 21. A P value less than 0.5 was considered significant. Results: The average age at the time of operation was 14.9 years (range 11.2-24.3). Recurrent dislocation occurred in 4 out of 20 cases (20%). It was noticeable that out of those 4 patients 2 patients had a lateral release in addition to the "modified Adductor Sling Technique" due to lateral hyperpression. No other patients had a lateral release in our patient population. Also, out of those 4 patients 3 patients had an additional maltracking of the patella, caused by a high TTTG, severe trochlea dysplasia or additional axial deformity. The overall Kujala Score was 87 (range 46-100) points, in patients without re-dislocation it was 94 (range 46-100) points. The overall Lysholm Score was 85 (range 39-100) points, in the group without re-dislocation 90 (range

  6. Once a myth, now an object of study - How the perception of comets has changed over the centuries

    NASA Astrophysics Data System (ADS)

    2004-02-01

    torches hurled into the air by forest spirits - the more easily to detect humans foolish enough to stay out at night. For some Australian aborigines, comets are flaming sticks ridden by mighty shamans. Efforts to provide a scientific explanation of the ‘cometa aster’ (‘hairy star’) phenomenon stretch back to ancient times. A widely held view was that comets were in some way connected with processes at work in the atmosphere. In Meteorologica, Aristotle (384-322 BC) described how inflammable gases escape from clefts in rocks, collect in the upper layers of the sub-lunar world (‘world under the Moon’) and ignite. Rapid release of such gases produced a shooting star; when let out slowly, they gave rise to a comet. That was Aristotle’s best shot - and he was well aware of his limited insight into the question. As he himself acknowledged: “As we have no demonstrable basis for assertions about comets, I have to settle for an interpretation that does not conflict with established truths.” Admittedly such truths were thin on the ground at the time. Comets - something of a disaster As the centuries unfolded, what could be called the opposite view - that the comets were responsible for intense heat spells - also gained a considerable audience, though there was just as little truth in it. The natural philosophers went one further. They said comets lead to heat, heat to storms and storms to natural disasters. Pliny the Elder for example (born circa 23 AD) listed twelve cometary phenomena according to their external appearances. And he assigned one natural disaster to each class. The Christian Middle Ages no longer saw cometary phenomena as the blind raging of an even blinder nature, preferring to interpret them as signs from God. Theologians such as Saint Hildegard of Bingen (1098-1179) and Albert Magnus (1200-1280) cited holy scripture. The Book of Jeremiah for example (1:11,12), in which God caused a fearsome “rod of an almond tree” to appear in the sky, a

  7. PREFACE: XII Latin American workshop on plasma physics (17-21 September 2007, Caracas, Venezuela)

    NASA Astrophysics Data System (ADS)

    Puerta, Julio

    2008-10-01

    Deutsch, Ricardo Galvao, Carlos Hidalgo, Paulo Sakanaka, Konosuke Sato, Malcom Haines and Maher Boulos. The general feeling is that these mini-courses were very successful. As an original idea of Professor Ricardo Magnus Osorio Galvão, Director of Centro Brasileiro de Pesquisas Físicas, we saluted the creation of The Vladimir Tsypin Award to the best Poster in the meeting. This prize was presented by Professor Galvão in memoriam of Vladimir Semenovich Tsypin. It was suggested that the granting of this award be made in every meeting from now on. We think that it is very important to emphasise the mini-courses due to the necessity of increasing in the near future a better formation for our young scientists. The contributions of all the lecturers are greatly appreciated. We had the typical fields in plasma physics as in past meetings. We also appreciated very much the lectures of Professor Malcolm Haines, Professor Sergey Popel, Professor Claude Deutsch, and Professor Antony Peratt for their very interesting talks on the Z-Pinch recorded to prehistory. Special thanks again to these lecturers since they have joined and honoured our meetings in the past as well. As in the VII LAWPP, all the sessions of the workshop were held at the Universidad Simon Bolivar campus, located in the nice green Valley of Sartenejas near Caracas. We also appreciate the stimulus and the financial support that we have always had for the preparation of these workshops from our institution by means of its authorities: Professor Benjamin Sharifker (Rector), Professor Aura Lopez (Dean of Academic Activities), (Professor Jose Luis Paz (Dean of Research and Development), Professor Pedro Berrisbeitia (Dean of Postgraduate Studies) and Professor William Colmenares (Dean of Extended Activities). We must also mention and appreciate the collaboration of architect Alejandro Chataing Roncajolo as Secretary and Coordinator of the Congress, as well as the daily important collaborations of our students Anais M

  8. Alternaria redefined

    PubMed Central

    Woudenberg, J.H.C.; Groenewald, J.Z.; Binder, M.; Crous, P.W.

    2013-01-01

    combinations - Alternaria abundans (E.G. Simmons) Woudenb. & Crous, Alternaria alternariae (Cooke) Woudenb. & Crous, Alternaria atra (Preuss) Woudenb. & Crous, Alternaria bornmuelleri (Magnus) Woudenb. & Crous, Alternaria botrytis (Preuss) Woudenb. & Crous, Alternaria caespitosa (de Hoog & C. Rubio) Woudenb. & Crous, Alternaria cantlous (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria caricis (E.G. Simmons) Woudenb. & Crous, Alternaria cinerea (Baucom & Creamer) Woudenb. & Crous, Alternaria didymospora (Munt.-Cvetk.) Woudenb. & Crous, Alternaria fulva (Baucom & Creamer) Woudenb. & Crous, Alternaria hyacinthi (de Hoog & P.J. Mull. bis) Woudenb. & Crous, Alternaria indefessa (E.G. Simmons) Woudenberg & Crous, Alternaria leptinellae (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria lolii (E.G. Simmons & C.F. Hill) Woudenb. & Crous, Alternaria multiformis (E.G. Simmons) Woudenb. & Crous, Alternaria obclavata (Crous & U. Braun) Woudenb. & Crous, Alternaria obovoidea (E.G. Simmons) Woudenb. & Crous, Alternaria oudemansii (E.G. Simmons) Woudenb. & Crous, Alternaria oxytropis (Q. Wang, Nagao & Kakish.) Woudenb. & Crous, Alternaria penicillata (Corda) Woudenb. & Crous, Alternaria planifunda (E.G. Simmons) Woudenb. & Crous, Alternaria proteae (E.G. Simmons) Woudenb. & Crous, Alternaria scirpinfestans (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria scirpivora (E.G. Simmons & D.A. Johnson) Woudenb. & Crous, Alternaria septospora (Preuss) Woudenb. & Crous, Alternaria slovaca (Svob.-Pol., L. Chmel & Bojan.) Woudenb. & Crous, Alternaria subcucurbitae (Yong Wang bis & X.G. Zhang) Woudenb. & Crous, Alternaria tellustris (E.G. Simmons) Woudenb. & Crous, Alternaria tumida (E.G. Simmons) Woudenb. & Crous, Paradendryphiella salina (G.K. Sutherl.) Woudenb. & Crous, Paradendryphiella arenariae (Nicot) Woudenb. & Crous. New names - Alternaria aspera Woudenb. & Crous, Alternaria botryospora Woudenb. & Crous, Alternaria brassicae-pekinensis Woudenb. & Crous, Alternaria

  9. The Doryctinae (Braconidae) of Costa Rica: genera and species of the tribe Heterospilini

    PubMed Central

    Marsh, Paul M.; Wild, Alexander L.; Whitfield, James B.

    2013-01-01

    . n., H. diecinueve sp. n., H. dieciocho sp. n., H. dieciseis sp. n., H. diecisiete sp. n., H. diez sp. n., H. doce sp. n., H. dos sp. n., H. dulcus sp. n., H. eberhardi sp. n., H. ektorincon sp. n., H. emilius sp. n., H. empalmensis sp. n., H. enderleini sp. n., H. escazuensis sp. n., H. fahringeri sp. n., H. fischeri sp. n., H. flavidus sp. n., H. flavisoma sp. n., H. flavostigmus sp. n., H. foersteri sp. n., H. fonsecai sp. n., H. fournieri sp. n., H. gahani sp. n., H. garifuna sp. n., H. gauldi sp. n., H. golfodulcensis sp. n., H. gouleti sp. n., H. granulatus sp. n., H. grisselli sp. n., H. guanacastensis sp. n., H. guapilensis sp. n., H. hachaensis sp. n., H. halidayi sp. n., H. hansoni sp. n., H. hansonorum sp. n., H. haplocarinus sp. n., H. hedqvisti sp. n., H. hera sp. n., H. heredius sp. n., H. hespenheidei sp. n., H. holleyae sp. n., H. huddlestoni sp. n., H. huetares sp. n., H. hypermekus sp. n., H. itza sp. n., H. ixcatec sp. n., H. ixil sp. n., H. jabillosensis sp. n., H. jakaltek sp. n., H. janzeni sp. n., H. jennieae sp. n., H. jonmarshi sp. n., H. jupiter sp. n., H. kellieae sp. n., H. kiefferi sp. n., H. kikapu sp. n., H. kulai sp. n., H. kuna sp. n., H. lapierrei sp. n., H. lasalturus sp. n., H. laselvus sp. n., H. leenderti sp. n., H. leioenopus sp. n., H. leiponotaulus sp. n., H. lenca sp. n., H. levis sp. n., H. leviscutum sp. n., H. levitergum sp. n., H. limonensis sp. n., H. longinoi sp. n., H. longisulcus sp. n., H. longius sp. n., H. luteogaster sp. n., H. luteoscutum sp. n., H. luteus sp. n., H. macrocarinus sp. n., H. macrocaudatus sp. n., H. magnus sp. n., H. malaisei sp. n., H. mam sp. n., H. maritzaensis sp. n., H. mars sp. n., H. masneri sp. n., H. masoni sp. n., H. mellosus sp. n., H. menkei sp. n., H. mercury sp. n., H. milleri sp. n., H. miskito sp. n., H. mixtec sp. n., H. monteverde sp. n., H. mopanmaya sp. n., H. muertensis sp. n., H. muesebecki sp. n., H. nahua sp. n., H. neesi sp. n., H. nemestrinus sp. n., H. nephilim sp. n., H

  10. The Doryctinae (Braconidae) of Costa Rica: genera and species of the tribe Heterospilini.

    PubMed

    Marsh, Paul M; Wild, Alexander L; Whitfield, James B

    2013-01-01

    . diecinueve sp. n., H. dieciocho sp. n., H. dieciseis sp. n., H. diecisiete sp. n., H. diez sp. n., H. doce sp. n., H. dos sp. n., H. dulcus sp. n., H. eberhardi sp. n., H. ektorincon sp. n., H. emilius sp. n., H. empalmensis sp. n., H. enderleini sp. n., H. escazuensis sp. n., H. fahringeri sp. n., H. fischeri sp. n., H. flavidus sp. n., H. flavisoma sp. n., H. flavostigmus sp. n., H. foersteri sp. n., H. fonsecai sp. n., H. fournieri sp. n., H. gahani sp. n., H. garifuna sp. n., H. gauldi sp. n., H. golfodulcensis sp. n., H. gouleti sp. n., H. granulatus sp. n., H. grisselli sp. n., H. guanacastensis sp. n., H. guapilensis sp. n., H. hachaensis sp. n., H. halidayi sp. n., H. hansoni sp. n., H. hansonorum sp. n., H. haplocarinus sp. n., H. hedqvisti sp. n., H. hera sp. n., H. heredius sp. n., H. hespenheidei sp. n., H. holleyae sp. n., H. huddlestoni sp. n., H. huetares sp. n., H. hypermekus sp. n., H. itza sp. n., H. ixcatec sp. n., H. ixil sp. n., H. jabillosensis sp. n., H. jakaltek sp. n., H. janzeni sp. n., H. jennieae sp. n., H. jonmarshi sp. n., H. jupiter sp. n., H. kellieae sp. n., H. kiefferi sp. n., H. kikapu sp. n., H. kulai sp. n., H. kuna sp. n., H. lapierrei sp. n., H. lasalturus sp. n., H. laselvus sp. n., H. leenderti sp. n., H. leioenopus sp. n., H. leiponotaulus sp. n., H. lenca sp. n., H. levis sp. n., H. leviscutum sp. n., H. levitergum sp. n., H. limonensis sp. n., H. longinoi sp. n., H. longisulcus sp. n., H. longius sp. n., H. luteogaster sp. n., H. luteoscutum sp. n., H. luteus sp. n., H. macrocarinus sp. n., H. macrocaudatus sp. n., H. magnus sp. n., H. malaisei sp. n., H. mam sp. n., H. maritzaensis sp. n., H. mars sp. n., H. masneri sp. n., H. masoni sp. n., H. mellosus sp. n., H. menkei sp. n., H. mercury sp. n., H. milleri sp. n., H. miskito sp. n., H. mixtec sp. n., H. monteverde sp. n., H. mopanmaya sp. n., H. muertensis sp. n., H. muesebecki sp. n., H. nahua sp. n., H. neesi sp. n., H. nemestrinus sp. n., H. nephilim sp. n., H. nephus sp. n

  11. PREFACE: Turbulent Mixing and Beyond Turbulent Mixing and Beyond

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana I.; Gauthier, Serge; Rosner, Robert

    2008-10-01

    ) Institute for Laser Engineering (ILE), Osaka, Japan (Division Head: Dr K Nishihara) Illinois Institute of Technology (IIT), Chicago, USA (College of Science and Letters, Department of Applied Mathematics: Dr S I Abarji) and thanks them for making this event possible. The Organizing Committee appreciates the assistance of Suzie Radosic (administrator and assistant, ICTP) Daniil Ilyin (web-master, Chicago) Elena Magnus (assistant, Chicago) We express our gratitude for the help with the Conference Program to the members of the Scientific Advisory Committee S I Abarzhi (The University of Chicago, Illinois Institute of Technology, USA) G Ahlers (University of California at Santa Barbara, USA) M J Andrews (Los Alamos National Laboratory, Texas A & M University, USA) S I Anisimov (Landau Institute for Theoretical Physics, Russia) E Bodenschatz (Max Plank Institute, Gottingen, Germany) S Dalziel (DAMTP, University of Cambridge, UK) R Ecke (Los Alamos National Laboratory, USA) H J Fernando (Arizona State University, USA) S Gauthier (Commissariat à l'Energie Atomique, France) G A Glatzmaier (University of California at Santa Cruz, USA) W A Goddard III (California Institute of Technology, USA) L P Kadanoff (The University of Chicago, USA) D Q Lamb (The University of Chicago, USA) D P Lathrop (University of Maryland, USA) S Lebedev (Imperial College, UK) P Manneville (Ecole Polytechnique, France) D I Meiron (California Institute of Technology, USA) H Nagib (Illinois Institute of Technology, Chicago, USA) J Niemela (International Center for Theoretical Physics, Italy) K Nishihara (Institute for Laser Engineering, Osaka, Japan) S A Orszag (Yale University, USA) E Ott (University of Maryland, USA) N Peters (RWTS, Aachen, Germany) S B Pope (Cornell, USA) B A Remington (Lawrence Livermore National Laboratory, USA) R Rosner (Argonne National Laboratory and The University of Chicago, USA) A Schmidt (Naval Research Laboratory, USA) K R Sreenivasan (International Centre for Theoretical Physics

  12. Comet or Asteroid?

    NASA Astrophysics Data System (ADS)

    1997-11-01

    When is a minor object in the solar system a comet? And when is it an asteroid? Until recently, there was little doubt. Any object that was found to display a tail or appeared diffuse was a comet of ice and dust grains, and any that didn't, was an asteroid of solid rock. Moreover, comets normally move in rather elongated orbits, while most asteroids follow near-circular orbits close to the main plane of the solar system in which the major planets move. However, astronomers have recently discovered some `intermediate' objects which seem to possess properties that are typical for both categories. For instance, a strange object (P/1996 N2 - Elst-Pizarro) was found last year at ESO ( ESO Press Photo 36/96 ) which showed a cometary tail, while moving in a typical asteroidal orbit. At about the same time, American scientists found another (1996 PW) that moved in a very elongated comet-type orbit but was completely devoid of a tail. Now, a group of European scientists, by means of observations carried out at the ESO La Silla observatory, have found yet another object that at first appeared to be one more comet/asteroid example. However, continued and more detailed observations aimed at revealing its true nature have shown that it is most probably a comet . Consequently, it has received the provisional cometary designation P/1997 T3 . The Uppsala-DLR Trojan Survey Some time ago, Claes-Ingvar Lagerkvist (Astronomical Observatory, Uppsala, Sweden), in collaboration with Gerhard Hahn, Stefano Mottola, Magnus Lundström and Uri Carsenty (DLR, Institute of Planetary Exploration, Berlin, Germany), started to study the distribution of asteroids near Jupiter. They were particularly interested in those that move in orbits similar to that of Jupiter and which are located `ahead' of Jupiter in the so-called `Jovian L4 Lagrangian point'. Together with those `behind' Jupiter, these asteroids have been given the names of Greek and Trojan Heroes who participated in the famous Trojan war

  13. Once a myth, now an object of study - How the perception of comets has changed over the centuries

    NASA Astrophysics Data System (ADS)

    2004-02-01

    torches hurled into the air by forest spirits - the more easily to detect humans foolish enough to stay out at night. For some Australian aborigines, comets are flaming sticks ridden by mighty shamans. Efforts to provide a scientific explanation of the ‘cometa aster’ (‘hairy star’) phenomenon stretch back to ancient times. A widely held view was that comets were in some way connected with processes at work in the atmosphere. In Meteorologica, Aristotle (384-322 BC) described how inflammable gases escape from clefts in rocks, collect in the upper layers of the sub-lunar world (‘world under the Moon’) and ignite. Rapid release of such gases produced a shooting star; when let out slowly, they gave rise to a comet. That was Aristotle’s best shot - and he was well aware of his limited insight into the question. As he himself acknowledged: “As we have no demonstrable basis for assertions about comets, I have to settle for an interpretation that does not conflict with established truths.” Admittedly such truths were thin on the ground at the time. Comets - something of a disaster As the centuries unfolded, what could be called the opposite view - that the comets were responsible for intense heat spells - also gained a considerable audience, though there was just as little truth in it. The natural philosophers went one further. They said comets lead to heat, heat to storms and storms to natural disasters. Pliny the Elder for example (born circa 23 AD) listed twelve cometary phenomena according to their external appearances. And he assigned one natural disaster to each class. The Christian Middle Ages no longer saw cometary phenomena as the blind raging of an even blinder nature, preferring to interpret them as signs from God. Theologians such as Saint Hildegard of Bingen (1098-1179) and Albert Magnus (1200-1280) cited holy scripture. The Book of Jeremiah for example (1:11,12), in which God caused a fearsome “rod of an almond tree” to appear in the sky, a