Now showing items 905-924 of 4818

    • Corticospinal responses of resistance-trained and un-trained males during dynamic muscle contractions 

      Tallent, J.; Goodall, S.; Hortobágyi, T.; St Clair Gibson, A.; Howatson, G. (ELSEVIER, 2013)
      Little is known regarding the modulation and the plasticity of the neural pathway interconnecting elements of the central nervous system and skeletal muscle in resistant-trained individuals. The aim of the study was to ...
    • Cortisol: brain-derived neurotrophic factor ratio associated with silent ischaemia in a black male cohort: the SABPA study 

      Schutte, Christiaan E.; Malan, Leoné; Scheepers, Jacobus D.; Oosthuizen, Woudri; Cockeran, Maricke; Malan, Nicolaas T. (SASA, 2016)
      Aim: Emotional distress has been associated with cardiovascular disease (CVD) in Africans. Cortisol and brain-derived neurotrophic factor (BDNF), as markers of emotional distress, increase cardiometabolic risk. We therefore ...
    • A cosmic collider: was the IceCube neutrino generated in a precessing jet-jet interaction in TXS 0506+056? 

      Britzen, S.; Böttcher, M.; Fendt, C.; Zajaček, M.; Jaron, F. (EDP Sciences, 2019)
      Context. The neutrino event IceCube−170922A appears to originate from the BL Lac object TXS 0506+056. To understand the neutrino creation process and to localize the emission site, we studied the radio images of the jet ...
    • Cosmic ray diffusion tensor throughout the heliosphere 

      Pei, C.; Burger, R.A.; Bieber, J.W.; Breech, B.; Clem, J. (American Geophysical Union, 2010)
      We calculate the cosmic ray diffusion tensor based on a recently developed model of magnetohydrodynamic (MHD) turbulence in the expanding solar wind. Parameters of this MHD model are tuned by using published observations ...
    • Cosmic ray flux anisotropies caused by astrospheres 

      Scherer, K.; Strauss, R.D.; Ferreira, S.E.S.; Fichtner, H. (Elsevier, 2016)
      Huge astrospheres or stellar wind bubbles influence the propagation of cosmic rays at energies up to the TeV range and can act as small-scale sinks decreasing the cosmic ray flux. We model such a sink (in 2D) by a sphere ...
    • Cosmic ray flux at the earth in a variable heliosphere 

      Scherer, K.; Ferreira, S.E.S.; Potgieter, M.S.; Fichtner, H.; Heber, B. (Elsevier, 2008)
      In recent years the variability of the cosmic ray flux has become one of the main issues not only for the interpretation of the abundances of cosmogenic isotopes in cosmochronic archives like, e.g., ice cores, but also for ...
    • Cosmic ray modulation beyond the heliopause: a hybrid modeling approach 

      Strauss, R.D.; Potgieter, M.S.; Ferreira, S.E.S.; Fichtner, H.; Scherer, K. (IOP Publishing, 2013)
      Results from a newly developed hybrid cosmic ray (CR) modulation model are presented. In this approach, the transport of CRs is computed by incorporating the plasma flow from a magnetohydrodynamic model for the heliospheric ...
    • Cosmic ray modulation in the outer heliosphere: predictions for cosmic ray intensities up to the heliopause along Voyager 1 and 2 trajectories 

      Manuel, R.; Ferreira, S.E.S.; Potgieter, M.S. (Elsevier, 2011)
      Time dependent cosmic ray modulation in the outer heliosphere is calculated and results are compared to Voyager 1 and 2 observations using a two-dimensional time-dependent cosmic ray transport model. We predict possible ...
    • Cosmic ray modulation with a Fisk-type heliospheric magnetic field and a latitude-dependent solar wind speed 

      Hitge, M.; Burger, R.A. (Elsevier, 2009)
      The effect of a latitude-dependent solar wind speed on a Fisk heliospheric magnetic field [Fisk, L. A. Motion of the footpoints of heliospheric magnetic field lines at the Sun: implications for recurrent energetic particle ...
    • Cosmic rays in astrospheres 

      Scherer, K.; Van der Schyff, A.; Ferreira, S.E.S.; Strauss, R.D.; Bomans, D.J. (EDP Sciences, 2015)
      Context: Cosmic rays passing through large astrospheres can be efficiently cooled inside these “cavities” in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front ...
    • Cosmic rays in the dynamic heliosheath 

      Ferreira, S.E.S.; Potgieter, M.S.; Scherer, K. (Elsevier, 2008)
      Cosmic ray modulation in the outer heliosphere is discussed from a modeling perspective. Emphasis is on the transport and acceleration of these particles at and beyond the solar wind termination shock in the inner heliosheath ...
    • Cosmic rays in the dynamic heliosphere 

      Potgieter, Marius S. (Japan Society of Plasma Science and Nuclear Fusion Research, 2009)
      he relation between the dynamics of the heliosphere, its shape and geometry, so lar activity and cosmic ray variations is addressed. The global features of the helio sphere influence what happens inside its boundaries ...
    • Cosmic rays in the heliosphere: observations 

      Moraal, Harm (Elsevier, 2014)
      This contribution to the 100th commemoration of the discovery of cosmic rays (6–8 August, 2012 in Bad Saarow, Germany) is about observations of those cosmic rays that are sensitive to the structure and the dynamics of the ...
    • Cosmic rays in the inner heliosphere: insights from observations, theory and models 

      Potgieter, M.S. (Springer, 2011)
      The global modulation of galactic cosmic rays in the inner heliosphere is determined by four major mechanisms: convection, diffusion, particle drifts (gradient, curvature and current sheet drifts), and adiabatic energy ...
    • Cosmic-ray acceleration and escape from post-adiabatic supernova remnants 

      Brose, R.; Sushch, I.; Pohl, M.; Petruk, O.; Kuzyo, T. (EDP Sciences, 2020)
      Context. Supernova remnants are known to accelerate cosmic rays on account of their nonthermal emission of radio waves, X-rays, and gamma rays. Although there are many models for the acceleration of cosmic rays in supernova ...
    • The cosmic-ray ground-level enhancement of 1989 September 29 

      Moraal, H.; Cabellero-Lopez, R.A. (IOP Publishing, 2014)
      The ground-level enhancement (GLE) of 1989 September 29 is one of the largest of 71 solar energetic particle events observed by neutron monitors on Earth. It was smaller than the record-breaking GLE 5 of 1956 February 23, ...
    • Cosmic-ray modulation equations 

      Moraal, Harm (Springer, 2011)
      The temporal variation of the cosmic-ray intensity in the heliosphere is called cosmic-ray modulation. The main periodicity is the response to the 11-year solar activity cycle. Other variations include a 27-day solar ...
    • Cosmic-ray modulation: an ab initio approach 

      Engelbrecht, N.E.; Burger, R.A. (Springer Verlag, 2014)
      A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model ...
    • A cosmic-ray positron anisotropy due to two middle-aged, nearby pulsars? 

      Büsching, I.; De Jager, O.C.; Potgieter, M.S.; Venter, C. (IOP Publishing, 2008)
      Geminga and B0656+14 are the closest pulsars with characteristic ages in the range of 100 kyr to 1 Myr. They both have spin-down powers of the order 3 × 1034 ergs s–1 at present. The winds of these pulsars had most probably ...
    • Cosmic-ray positrons from millisecond pulsars 

      Venter, C.; Kopp, A.; Büsching, I.; Harding, A.K.; Gonthier, P.L. (IOP Publishing, 2015)
      Observations by the Fermi Large Area Telescope of γ-ray millisecond pulsar (MSP) light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may ...