James P Keener

Summary

Affiliation: University of Utah
Country: USA

Publications

  1. pmc A biophysical model for defibrillation of cardiac tissue
    J P Keener
    Department of Mathematics, University of Utah, Salt Lake City 84112, USA
    Biophys J 71:1335-45. 1996
  2. doi request reprint Exact reductions of Markovian dynamics for ion channels with a single permissive state
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT, 84112, USA
    J Math Biol 60:473-9. 2010
  3. ncbi request reprint How Salmonella Typhimurium measures the length of flagellar filaments
    J P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
    Bull Math Biol 68:1761-78. 2006
  4. ncbi request reprint Stochastic calcium oscillations
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    Math Med Biol 23:1-25. 2006
  5. ncbi request reprint A model for length control of flagellar hooks of Salmonella typhimurium
    J P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 234:263-75. 2005
  6. ncbi request reprint The topology of defibrillation
    James P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 230:459-73. 2004
  7. doi request reprint A molecular ruler mechanism for length control of extended protein structures in bacteria
    J P Keener
    Department of Mathematics, University of Utah, USA
    J Theor Biol 263:481-9. 2010
  8. ncbi request reprint Model for the onset of fibrillation following coronary artery occlusion
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    J Cardiovasc Electrophysiol 14:1225-32. 2003
  9. ncbi request reprint The effect of spatial scale of resistive inhomogeneity on defibrillation of cardiac tissue
    James P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 223:233-48. 2003
  10. ncbi request reprint Diffusion induced oscillatory insulin secretion
    J P Keener
    Department of Mathematics, University of Utah, Salt Lake City 84112, USA
    Bull Math Biol 63:625-41. 2001

Collaborators

Detail Information

Publications28

  1. pmc A biophysical model for defibrillation of cardiac tissue
    J P Keener
    Department of Mathematics, University of Utah, Salt Lake City 84112, USA
    Biophys J 71:1335-45. 1996
    ..To illustrate the usefulness of the model, numerical stimulations are used to show the difference between successful and unsuccessful defibrillation of large pieces of tissue...
  2. doi request reprint Exact reductions of Markovian dynamics for ion channels with a single permissive state
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT, 84112, USA
    J Math Biol 60:473-9. 2010
    ..Finally, we conclude that solutions of the reduced model are globally asymptotically stable solutions of the full master equation system...
  3. ncbi request reprint How Salmonella Typhimurium measures the length of flagellar filaments
    J P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
    Bull Math Biol 68:1761-78. 2006
    ..The combination of this regulatory network with the length-dependent rate of growth enable the bacterium to detect length shortening and regrow severed flagellar filaments...
  4. ncbi request reprint Stochastic calcium oscillations
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    Math Med Biol 23:1-25. 2006
    ..By solving this model numerically, information about the timing of whole-cell calcium release is obtained. The results of this analysis show a transition to oscillations that agrees well with data and with Monte Carlo simulations...
  5. ncbi request reprint A model for length control of flagellar hooks of Salmonella typhimurium
    J P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 234:263-75. 2005
    ..We propose that this transition can be detected by the secretant FliK, allowing FliK to interact with FlhB thereby changing the secretion target of the type III secretion machinery and terminating the growth of the hook...
  6. ncbi request reprint The topology of defibrillation
    James P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 230:459-73. 2004
    ..Using topological arguments we draw the general conclusion that with a generic placement of stimulating electrodes, large-scale virtual electrodes do not give an adequate explanation for the mechanism of defibrillation...
  7. doi request reprint A molecular ruler mechanism for length control of extended protein structures in bacteria
    J P Keener
    Department of Mathematics, University of Utah, USA
    J Theor Biol 263:481-9. 2010
    ..Thus, it is much more likely that interaction will occur when the hook is long than when the hook is short...
  8. ncbi request reprint Model for the onset of fibrillation following coronary artery occlusion
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    J Cardiovasc Electrophysiol 14:1225-32. 2003
    ..quot; The border zone arrhythmia may drive a "breakup instability" (related to the action potential duration restitution instability) in the surrounding tissue, leading to self-sustained fibrillation...
  9. ncbi request reprint The effect of spatial scale of resistive inhomogeneity on defibrillation of cardiac tissue
    James P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, UT 84112, USA
    J Theor Biol 223:233-48. 2003
    ..With small spatial scale inhomogeneity, there are no similar restrictions...
  10. ncbi request reprint Diffusion induced oscillatory insulin secretion
    J P Keener
    Department of Mathematics, University of Utah, Salt Lake City 84112, USA
    Bull Math Biol 63:625-41. 2001
    ..Bull. Math. Biol., 57(1995), 569-591). Furthermore, with reasonable numbers for the experimental parameters and the diffusion of insulin, the model equations do not exhibit oscillations...
  11. ncbi request reprint The biphasic mystery: why a biphasic shock is more effective than a monophasic shock for defibrillation
    J P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT, 84112, USA
    J Theor Biol 200:1-17. 1999
    ..The effect can be seen easily in a model of a single cell and also in a cable model with a ring of excitable cells. Finally, we demonstrate the phenomenon in a two-dimensional model of cardiac tissue...
  12. doi request reprint Invariant manifold reductions for Markovian ion channel dynamics
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    J Math Biol 58:447-57. 2009
    ..We also use this to show that the original Hodgkin-Huxley formulations of potassium channel conductance and sodium channel conductance are the exact solutions of full Markov models for these channels...
  13. ncbi request reprint Perturbation analysis of spontaneous action potential initiation by stochastic ion channels
    James P Keener
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
    Phys Rev E Stat Nonlin Soft Matter Phys 84:011918. 2011
    ..We also explore why different diffusion approximation techniques fail to estimate the MFT...
  14. pmc Toward an understanding of fibrin branching structure
    Aaron L Fogelson
    Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
    Phys Rev E Stat Nonlin Soft Matter Phys 81:051922. 2010
    ..A higher rate of monomer supply leads to a gel with a higher branch concentration and with shorter fiber segments between branch points. The origin of this dependence is explained...
  15. ncbi request reprint Influence of the standard free energy on swelling kinetics of gels
    James P Keener
    Department of Mathematics, University of Utah, Salt Lake City, Utah 84112, USA
    Phys Rev E Stat Nonlin Soft Matter Phys 83:041802. 2011
    ....
  16. pmc Modeling electrical activity of myocardial cells incorporating the effects of ephaptic coupling
    Joyce Lin
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    Proc Natl Acad Sci U S A 107:20935-40. 2010
    ..This model can be relatively easily extended to higher dimensions while maintaining numerical efficiency and incorporating ephaptic effects through modeling of complex, irregular cellular geometry...
  17. doi request reprint Ephaptic coupling of cardiac cells through the junctional electric potential
    Elizabeth D Copene
    Department of Mathematics, The University of Utah, Salt Lake City, UT 84112, USA
    J Math Biol 57:265-84. 2008
    ..We find that there are two distinct types of propagation failure and we are able to characterize parameter space into regions of propagation success and the two different types of propagation failure...
  18. ncbi request reprint Fibrin gel formation in a shear flow
    Robert D Guy
    Department of Mathematics, University of Utah, 155 South 1400 East, Room 233, Salt Lake City, UT 84112 0090, USA
    Math Med Biol 24:111-30. 2007
    ..The results show that the thrombin inhibition rate, the gel permeability and the shear rate are key parameters in regulating the height of the fibrin gel...
  19. pmc Facilitation of intracellular H(+) ion mobility by CO(2)/HCO(3)(-) in rabbit ventricular myocytes is regulated by carbonic anhydrase
    K W Spitzer
    Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
    J Physiol 541:159-67. 2002
    ..By regulating the carbonic shuttle, CA regulates effective H(+)(i) mobility which, in turn, regulates the spatiotemporal uniformity of pH(i). This is postulated to be a major function of CA in heart...
  20. ncbi request reprint Low-Reynolds-number swimming in viscous two-phase fluids
    Jian Du
    Department of Mathematics, University of Utah, Salt Lake City, Utah 84112, USA
    Phys Rev E Stat Nonlin Soft Matter Phys 85:036304. 2012
    ..Our results indicate that both the swimming speed and efficiency may be decreased substantially relative to those for a single-phase fluid...
  21. doi request reprint A mechanomolecular model for the movement of chromosomes during mitosis driven by a minimal kinetochore bicyclic cascade
    Blerta Shtylla
    Mathematics Department, University of Utah, Salt Lake City, UT, USA
    J Theor Biol 263:455-70. 2010
    ..Our feedback control model can recreate chromosome movement from prometaphase to anaphase in good agreement with experimental data...
  22. ncbi request reprint Calsequestrin mediates changes in spontaneous calcium release profiles
    Nessy Tania
    Department of Mathematics, University of Utah, 155 S 1400 E Room 233, Salt Lake City, UT 84112, USA
    J Theor Biol 265:359-76. 2010
    ..Finally, we show that with increased bulk cytoplasmic calcium concentration, the CRU model exhibits deterministic oscillations...
  23. doi request reprint Ephaptic coupling in cardiac myocytes
    Joyce Lin
    Department of Mathematics, University of Utah, Salt Lake City, UT 84112, USA
    IEEE Trans Biomed Eng 60:576-82. 2013
    ....
  24. ncbi request reprint A mathematical study of volume shifts and ionic concentration changes during ischemia and hypoxia
    Chung Seon Yi
    Department of Mathematics, University of Utah, 155 South 1400 East, 233 JWB, Salt Lake City, Utah 84112, USA
    J Theor Biol 220:83-106. 2003
    ..The same mechanism is not present in cardiac ion models, and this may explain the qualitative difference in response shown in cardiac tissue...
  25. ncbi request reprint A mathematical model for quorum sensing in Pseudomonas aeruginosa
    J D Dockery
    Department of Mathematics, Montana State University, Bozeman, MT 59718, USA
    Bull Math Biol 63:95-116. 2001
    ..Using this model we show that quorum sensing works because of a biochemical switch between two stable steady solutions, one with low levels of autoinducer and one with high levels of autoinducer...
  26. ncbi request reprint Phase singularities and termination of spiral wave reentry
    James P Keener
    J Cardiovasc Electrophysiol 14:556-7; author reply 557-8. 2003
  27. ncbi request reprint The role of the biofilm matrix in structural development
    N G Cogan
    Mathematics Department, Tulane University, New Orleans, LA 70118, USA
    Math Med Biol 21:147-66. 2004
    ....
  28. doi request reprint A calcium-induced calcium release mechanism mediated by calsequestrin
    Young Seon Lee
    Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
    J Theor Biol 253:668-79. 2008
    ..Furthermore, this CICR model produces a nonlinear relationship between fractional jSR Ca(2+) release and jSR load. These findings agree with experimental observations in lipid bilayers and cardiac myocytes...