Conference talks & posters
2019
- P. Swaczyna,
Angular Scattering in Charge Exchange Collisions: Consequences for Interstellar Neutral Atoms Produced in the Outer Heliosheath,
talk, 23rd IBEX / 2nd IMAP Science Working Team Meeting, 18 - 20 June 2019, Santa Fe, NM, USA
- E. J. Zirnstein, D. J. McComas, N. A. Schwadron, M. A. Dayeh, J. Heerikhuisen, P. Swaczyna,
ong Scattering of keV Pickup Ions in the Local Interstellar Magnetic Field Draped Around Our Heliosphere: Implications for the IBEX Ribbon’s Source and IMAP,
talk, 18th Annual International Astrophysics Conference, 18 - 22 Feb. 2019, Pasadena, CA, USA
- P. Swaczyna, D. J. McComas, N. A. Schwadron,
Temperature and Non‐equilibrium Distributions of Interstellar Neutrals,
talk, 18th Annual International Astrophysics Conference, 18 - 22 Feb. 2019, Pasadena, CA, USA
2018
- E. Möbius, N. A. Schwadron, M. Bzowski, S. A. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. A. Lee, D. J. McComas, P. Swaczyna, J. M. Sokół, P. Wurz,
Precise Measurement of the Interstellar Flow with IMAP, Informed by IBEX Observations,
poster SH13C-2964, AGU Fall Meeting 2018, 10 - 14 Dec. 2018, Washington, DC, USA
- P. Swaczyna, D. J. McComas, E. J. Zirnstein,
Population of He+ Ions Co-moving with the Solar Wind in the Outer Heliosphere,
poster SH13C-2963, AGU Fall Meeting 2018, 10 - 14 Dec. 2018, Washington, DC, USA
- M. Bzowski, A. Czechowski, P. C. Frisch, S. A. Fuselier, A. Galli, J. Grygorczuk, J. Heerikhuisen, M. A. Kubiak, H. Kucharek, D. J. McComas, E. Möbius, N. A. Schwadron, J. D. Slavin, J. M. Sokół, P. Swaczyna, P. Wurz, E. Zirnstein,
The ionization state of the local interstellar matter revealed by IBEX observations of interstellar neutral atoms,
talk SH11A-05, AGU Fall Meeting 2018, 10 - 14 Dec. 2018, Washington, DC, USA
- E. Möbius, M. Bzowski, S. A. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. A. Lee, D. J. McComas, N. A. Schwadron, P. Swaczyna, J. M. Sokół, P. Wurz,
Precise measurement of the ISN flow with IMAP informed by IBEX observations,
talk, 22nd IBEX / 1st IMAP Science Working Team Meeting, 28 - 29 Aug. 2018, Princeton, NJ, USA
- P. Swaczyna
Prospect for observations of heavy ENAs from the heliosphere and the LISM on IMAP,
talk, 22nd IBEX / 1st IMAP Science Working Team Meeting, 28 - 29 Aug. 2018, Princeton, NJ, USA
- M. Bzowski, A. Czechowski, P. C. Frisch, S. A. Fuselier, A. Galli, J. Grygorczuk, J. Heerikhuisen, D. Heirtzler, M. A. Kubiak, H. Kucharek, D. J. McComas, E. Möbius, N. A. Schwadron, J. D. Slavin, J. M. Sokół, P. Swaczyna, P. Wurz, E. Zirnstein,
He+ density in the LISM based on observations of the helium Warm Breeze,
talk, 22nd IBEX / 1st IMAP Science Working Team Meeting, 28 - 29 Aug. 2018, Princeton, NJ, USA
- M. Bzowski, A. Czechowski, P. C. Frisch, S.A. Fuselier, A. Galli, J. Grygorczuk, J. Heerikhuisen, D. Heirtzler, M. A. Kubiak, H. Kucharek, D. J. McComas, E. Möbius, N. A. Schwadron, J. Slavin, J. M. Sokół, P. Swaczyna, P. Wurz, E. Zirnstein,
The Local Interstellar Medium revealed by IBEX observations of interstellar neutral atoms,
talk D1.2-0011-18, 42nd COSPAR Assembly, 14 - 22 July 2018, Pasadena, CA, USA (presenting author: P. Swaczyna)
- A. Galli, D. J. McComas, H. O. Funsten, S. A. Fuselier, P. Wurz, N. A. Schwadron, H. Kucharek, E. Möbius, F. Rahmanifard, M. Bzowski, J. M. Sokół, M. A. Kubiak, P. Swaczyna, I. Kowalska-Leszczyńska
The not so fast and furious – what can slow energetic neutral atoms and interstellar neutral hydrogen tell us about the heliosphere?,
talk D1.3-0001-18, 42nd COSPAR Assembly, 14 - 22 July 2018, Pasadena, CA, USA
- P. Swaczyna, M. Bzowski, J. M. Sokół
Modeling the time evolution of the IBEX Ribbon over the solar cycle,
talk D1.2-0009-18, 42nd COSPAR Assembly, 14 - 22 July 2018, Pasadena, CA, USA
- E. Möbius, M. Bzowski, S. A. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. A. Lee, D. J. McComas, N. Schwadron, P. Swaczyna, J. M. Sokół, P. Wurz,
Interstellar He flow analysis over the past 10 years with varying pointing strategies,
talk D1.2-0018-18, 42nd COSPAR Assembly, 14 - 22 July 2018, Pasadena, CA, USA
- M. Bzowski, A. Czechowski, P. C. Frisch, S. A. Fuselier, A. Galli, J. Grygorczuk, J. Heerikhuisen, D. Heirtzler, M. A. Kubiak, H. Kucharek, D. J. McComas, E. Möbius, N. A. Schwadron, J. Slavin, J. M. Sokół, P. Swaczyna, P. Wurz, E. Zirnstein,
The ionization state of H and He in the Local Interstellar Medium revealed by IBEX observations of interstellar neutral atoms,
poster, Solar Wind 15, 18 - 23 June 2018, Brussels, Belgium
- M. Bzowski, M. A. Kubiak, J. Heerikhuisen, A. Czechowski, J. Grygorczuk, P. Swaczyna, E. Zirnstein, J. M. Sokół,
Diagnosing the Local Interstellar Medium Using the Warm Breeze and IBEX Ribbon,
talk, 17th Annual International Astrophysics Conference, 5 - 9 Mar. 2018, Santa Fe, NM, USA
- P. Swaczyna, M. Bzowski, J. M. Sokół,
Modeling the Evolution of the IBEX Ribbon’s Position due to the Solar Cycle Variation of the Solar Wind Structure,
talk, 17th Annual International Astrophysics Conference, 5 - 9 Mar. 2018, Santa Fe, NM, USA
2017
- E. Möbius, E. Bower, M. Bzowski, S. A. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. A. Lee, D. J. McComas, N. Schwadron, P. Swaczyna, J. M. Sokół, P. Wurz,
Interstellar He Flow Analysis over the Past 9 Years with Observations over the Full IBEX-Lo Energy Range,
talk SH54B-08, AGU Fall Meeting 2017, 11 - 15 Dec. 2017, New Orleans, LA, USA
- M. Bzowski, A. Czechowski, H. O. Funsten, J. Grygorczuk, J. Heerikhuisen, M. A. Kubiak, E. Möbius, D. J. McComas, N. Schwadron, J. M. Sokół, P. Swaczyna, E. Zirnstein,
Observational Evidence For The Comet-Like Heliosphere,
talk SH54B-07, AGU Fall Meeting 2017, 11 - 15 Dec. 2017, New Orleans, LA, USA
- P. Swaczyna, M. Bzowski, J. M. Sokół,
Time-dependent models of ENA emission and comparison to the IBEX observations,
poster SH51D-2526, AGU Fall Meeting 2017, 11 - 15 Dec. 2017, New Orleans, LA, USA
- P. Swaczyna, M. Bzowski, M. A. Kubiak, J. M. Sokół, S. A. Fuselier, A. Galli, D. Heirtzler, H. Kucharek, D. J. McComas, E. Möbius, N. A. Schwadron, P. Wurz,
Interstellar neutrals observed by IBEX-Lo in ESA 1-3,
talk, 21st IBEX Science Working Team Meeting, 28 - 30 June 2017, Warsaw, Poland
- E. Möbius, D. Heirtzler, H. Kucharek, M. A. Lee, T. Leonard, N. Schwadron, E. Bower, M. Bzowski, M. A. Kubiak, P. Swaczyna, J. M. Sokół,
IBEX Observations and Modeling of the ISN Flow at 1 AU over the full Energy Range (an update),
talk, 21st IBEX Science Working Team Meeting, 28 - 30 June 2017, Warsaw, Poland
- A. Galli, P. Wurz, M. Bzowski, J. M. Sokół, P. Swaczyna, N. A. Schwadron, E. Möbius, H. Kucharek, J. Park, S. A. Fuselier, D. B. Reisenfeld, D. J. McComas,
The downwind hemisphere of the heliosphere: what do IBEX observations at low energies tell us and which questions remain open?,
poster EGU2017-3346, EGU General Assembly 2017, 23 - 28 Apr. 2017, Vienna, Austria
- P. Swaczyna, M. Bzowski, J. M. Sokół, E. R. Christian, H. O. Funsten, D. J. McComas, N. A. Schwadron,
Position of the IBEX ribbon as a key to understand its origin,
poster EGU2017-687, EGU General Assembly 2017, 23 - 28 Apr. 2017, Vienna, Austria
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Imaging heliosphere with energetic neutral atoms of heavy species – perspectives for ENA detectors on IMAP,
talk, 16th Annual International Astrophysics Conference, 6 - 10 Mar. 2017, Santa Fe, NM, USA
2016
- P. Swaczyna, M. Bzowski, J. M. Sokół, E. R. Christian, H. O. Funsten, D. J. McComas, N. A. Schwadron,
The parallax and the energy-dependent position of the IBEX Ribbon – implications for its origin,
poster SH31A-2541, AGU Fall Meeting 2016, 12 - 16 Dec. 2016, San Francisco, CA, USA
- E. Möbius, M. Bzowski, S. A. Fuselier, D. Heirtzler, H. Kucharek. M. A. Lee, T. W. Leonard, D. J. McComas, N. Schwadron, P. Swaczyna, J. M. Sokół, P. Wurz,
Interstellar He flow analysis over the past 8 years with IBEX neutral observations,
poster SH31A-2528, AGU Fall Meeting 2016, 12 - 16 Dec. 2016, San Francisco, CA, USA
- M. Bzowski, M. A. Kubiak, P. Swaczyna, J. M. Sokół, S. A. Fuselier, A. Galli, D. Heirtzler, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, J. Park, N. A. Schwadron, P. Wurz,
Using IBEX data to constrain the heliosphere’s large-scale structure: Interstellar Neutral Gas and the Warm Breeze,
talk SH23A-07, AGU Fall Meeting 2016, 12 - 16 Dec. 2016, San Francisco, CA, USA
- M. Bzowski, M. A. Kubiak, P. Swaczyna, J. M. Sokół, S. A. Fuselier, A. Galli, D. Heirtzler, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, J. Park, N. A. Schwadron, P. Wurz,
Warm Breeze to probe the outer heliosheath,
talk, 20th IBEX Science Working Team Meeting, 9 - 12 Aug. 2016, Princeton, NJ, USA
- P. Swaczyna, M. Bzowski, J. M. Sokół, E. R. Christian, H. O. Funsten, D. J. McComas, N. A. Schwadron,
Implications for the origin of the ribbon from parallax and energy-dependent position in the sky,
talk, 20th IBEX Science Working Team Meeting, 9 - 12 Aug. 2016, Princeton, NJ, USA
2015
- M. Bzowski, P. Swaczyna, M. A. Kubiak, J. M. Sokół, S. A. Fuselier, A. Galli, D. Heirtzler, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, N. A. Schwadron, P. Wurz,
The local interstellar medium based on ISN He observations with Ulysses and IBEX and future IMAP measurements,
invited talk SH53C-09, AGU Fall Meeting 2015, 14 - 18 Dec. 2015, San Francisco, CA, USA
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Helium Energetic Neutral Atoms - a New Perspective for Heliospheric and Extraheliospheric Observations with IMAP,
invited talk SH53C-05, AGU Fall Meeting 2015, 14 - 18 Dec. 2015, San Francisco, CA, USA
- E. Möbius, M. Bzowski, C. Drews, P. Frisch, S. A. Fuselier, A. Galli, G. Gloeckler, M. A. Kubiak, H. Kucharek, M. Lee, T. W. Leonard, D. J. McComas, J. Park, N. A. Schwadron, P. Swaczyna, J.M. Sokół, B. Wood, P. Wurz,
Interstellar neutral flow characteristics, composition, and interaction with the heliosphere – neutral gas and pickup ion analysis from ongoing observations and perspectives for IMAP,
invited talk SH52B-04, AGU Fall Meeting 2015, 14 - 18 Dec. 2015, San Francisco, CA, USA
- J.M. Sokół, M. Bzowski, S. Grzedzielski, P. Swaczyna, M.A. Kubiak, A. Galli, P. Wurz, E. Möbius, H. Kucharek, S.A. Fuselier, D.J. McComas,
Hypothetical signals beyond the primary ISN He flow as perspective targets for IMAP,
poster SH41E-2407, AGU Fall Meeting 2015, 14 - 18 Dec. 2015, San Francisco, CA, USA
- P. Swaczyna et al.,
The IBEX Ribbon ridge position in the ram and antiram directions,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA
- J.M. Sokół, M. Bzowski, S. Grzedzielski, P. Swaczyna, M. A. Kubiak, A. Galli, P. Wurz, E. Möbius, H. Kucharek, N. A. Schwadron, S. A. Fuselier, D. J. McComas,
Beyond the ISN He flow: what IMAP might see,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA (presenting author: M. Bzowski)
- M. Bzowski, P. Swaczyna, M. A. Kubiak, J. M. Sokół, S. A. Fuselier, A. Galli, D. Heirtzler, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, N. A. Schwadron, P. Wurz,
Analysis of ISN He parameters in front of the heliosphere observed by IBEX,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA
- P. Swaczyna, J. M. Sokół, M. Bzowski, M. A. Kubiak, S. A. Fuselier, D. Heirtzler, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, N. A. Schwadron,
Intestellar neutral helium in the heliosphere from IBEX. Data corrections, uncertainties, and backgrounds, Warsaw Test Particle Model, and fitting method,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA
- A. Galli, P. Wurz, J. Park, H. Kucharek, E. Möbius, N. A. Schwadron, J. M. Sokół, M.Bzowski, M. A. Kubiak, P. Swaczyna, S. A. Fuselier, D. J. McComas,
Did IBEX detect interstellar neutral helium or oxygen in the fall season?,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA
- D. J. McComas, M. Bzowski, S. A. Fuselier, P. C. Frisch, A. Galli, V. V. Izmodenov, O. A. Katushkina, M. A. Kubiak, M. A. Lee, T. W. Leonard, E. Möbius, J. Park, N. A. Schwadron, J. M. Sokół, P. Swaczyna, B. E. Wood, P. Wurz,
Local interstellar medium: six years of direct sampling by the Interstellar Boundary Explorer,
talk, 19th IBEX Science Working Team Meeting, 18 - 20 Aug. 2015, Boulder, CO, USA
- J. M. Sokół, M. Tokumaru, M. Bzowski, P. Swaczyna,
Time variations of solar wind structure derived from interplanetary scintillation observations,
invited talk S4-29, workshop "New Paradigms for the Heliosphere", 29 June - 3 July 2015, Bad Honnef, Germany
- M. Bzowski, P. Swaczyna, M. A. Kubiak, J. M. Sokół, M. Banaszkiewicz, S. A. Fuselier, A. Galli, D. Heirtzler, M. Hłond, H. Kucharek, T. W. Leonard, D. J. McComas, E. Möbius, N. A. Schwadron, M. Witte, P. Wurz,
Interstellar neutral He ahead of the heliosphere: consolidation from direct sampling,
invited talk S3-70, workshop "New Paradigms for the Heliosphere", 29 June - 3 July 2015, Bad Honnef, Germany
- M. Bzowski, P. Swaczyna, M. A. Kubiak, J. M. Sokół, E. Möbius, T. Leonard, D. Heirtzler,
Analysis of IBEX-Lo Observations of Interstellar Neutral Helium from 2009 to 2014,
talk, 14th Annual International Astrophysics Conference, 19 - 24 Apr. 2015, Tampa, FL, USA
- A. Galli, P. Wurz, J. Park, H. Kucharek, E. Möbius, N. A. Schwadron, M. Bzowski, J. M. Sokół, M. A. Kubiak, P. Swaczyna, S. A. Fuselier, D. J. McComas,
Did IBEX detect interstellar neutral helium or oxygen from anti-ram direction?,
talk EGU2015-3659, EGU General Assembly 2015, 12 - 17 Apr. 2015, Vienna, Austria
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Energetic neutral helium atoms as a tool to study the heliosphere and the Local Interstellar Medium,
poster EGU2015-723, EGU General Assembly 2015, 12 - 17 Apr. 2015, Vienna, Austria
[pdf]
2014
- D. J. McComas, M. Bzowski, P. Frisch, S. Fuselier, M. A. Kubiak, H. Kucharek, T. Leonard, E. Möbius, N. Schwadron, J. M. Sokół, P. Swaczyna, M. Witte,
Warmer Local Interstellar Medium: Resolving the Ulysses-Ibex Enigma and the Promise of IMAP,
invited talk SH21D-03, AGU Fall Meeting 2014, 15 - 19 Dec. 2014, San Francisco, CA, USA
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Potential of Energetic Neutral Helium Atoms to Resolve Structure of the Local Interstellar Medium within 0.1 parsec,
talk SH21D-02, AGU Fall Meeting 2014, 15 - 19 Dec. 2014, San Francisco, CA, USA
[pdf]
- E. Möbius, M. Bzowski, P. Frisch, S. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. Lee, T. Leonard, D. J. McComas, N. Schwadron, J. M. Sokół, P. Swaczyna, P. Wurz,
Local Interstellar Cloud Temperatures as Observed with IBEX,
poster SH11C-4060, AGU Fall Meeting 2014, 15 - 19 Dec. 2014, San Francisco, CA, USA
- M. Bzowski, M. A. Kubiak, J. M. Sokół, P. Swaczyna, E. Möbius, T. Leonard, D. Heirtzler, M. Hłond, M. Banaszkiewicz, M. Witte, P. Wurz, D. Rodriguez, N. Schwadron, S. Fuselier, D. J. McComas, H. Kucharek,
Interstellar He parameters in front of the heliosphere: view from IBEX and Ulysses,
poster SH11C-4056, AGU Fall Meeting 2014, 15 - 19 Dec. 2014, San Francisco, CA, USA (presenting author: P. Swaczyna)
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Expected fluxes of energetic neutral helium atoms from the heliosheath and the IBEX Ribbon,
talk, 18th IBEX Science Working Team Meeting, 14 - 18 July 2014, Durham, NH, USA
- P. Swaczyna, M. Bzowski, M. A. Kubiak,
Investigating uncertainties in the IBEX-Lo interstellar neutral helium measurements and including them in the Warsaw Test Particle Model,
talk, 18th IBEX Science Working Team Meeting, 14 - 18 July 2014, Durham, NH, USA
- M. A. Kubiak, M. Bzowski, P. Swaczyna, J.M. Sokół,
NIS He flow after 2012 seen from Warsaw: present status,
talk, 18th IBEX Science Working Team Meeting, 14 - 18 July 2014, Durham, NH, USA
- P. Swaczyna, S. Grzedzielski, M. Bzowski,
Fluxes of energetic neutral helium atoms from the heliosheath and the IBEX Ribbon,
poster EGU2014-223, EGU General Assembly 2014, 27 Apr. - 2 May 2014, Vienna, Austria
- J. M. Sokół, P. Swaczyna, M. Bzowski, M. Tokumaru,
Heliolatitude structure of the solar wind proton speed and density at 1 AU for heliospheric modeling,
talk EGU2014-222, EGU General Assembly 2014, 27 Apr. - 2 May 2014, Vienna, Austria
- M. Bzowski, M. A. Kubiak, J. M. Sokół, P. Swaczyna, S. Grzedzielski, V. V. Izmodenov, D. B. Alexashov, E. Möbius, T. Leonard, P. Wurz, S. A. Fuselier, D. J. McComas,
Warm Helium Breeze from the starboard bow discovered in the heliosphere,
talk, 13th Annual International Astrophysics Conference, 10 - 14 Mar. 2014, Myrtle Beach, SC, USA
2013
- M. Bzowski, E. Möbius, S.A. Fuselier, D. Heirtzler, M. A. Kubiak, H. Kucharek, M. A. Lee, D. J. McComas, J. Park, N. A. Schwadron, J. M. Sokół, P. Wurz, T. Leonard, D. Rodriguez, V. V. Izmodenov, D. B. Alexashov, P. Swaczyna, S. Grzedzielski, P. Bochsler,
Interstellar gas flow measurements with the Interstellar Boundary Explorer (IBEX) – implications on heliospheric boundary diagnostic,
invited talk SH13B-03, AGU Fall Meeting 2013, 9 - 13 Dec. 2013, San Francisco, CA, USA
- M. Bzowski, M.A. Kubiak, J.M. Sokół, P. Swaczyna, E. Möbius, T. Leonard, H. Kucharek, D.B. Alexashov, V.V. Izmodenov, D.J. McComas, G. Livadiotis,
New population of neutral helium in the heliosphere discovered by IBEX,
poster SH23C-2118, AGU Fall Meeting 2013, 9 - 13 Dec. 2013, San Francisco, CA, USA
- D. Sokołowska in collaboration with M. Krawczyk, B. Świeżewska, P. Swaczyna,
Inert Doublet Model in light of new experimental results: combining astrophysial and the LHC data,
Scalars 2013, 12 - 16 Sept. 2013, Warsaw, Poland
- B. Świeżewska in collaboration with M. Krawczyk, D. Sokołowska, P. Swaczyna,
Higgs decays to γγ and Zγ in the Inert Doublet Model,
talk, Scalars 2013, 12 - 16 Sept. 2013, Warsaw, Poland
- B. Świeżewska in collaboration with M. Krawczyk, D. Sokołowska, P. Swaczyna,
Higgs → γγ, Zγ in the Inert Doublet Model,
talk, Matter to the Deepest, XXXVII International Conference of Theoretical Physics, 1 - 6 Sept. 2013, Ustroń, Poland
[DOI,
arXiv,
ADS]
- D. Sokołowska in collaboration with M. Krawczyk, B. Świeżewska, P. Swaczyna,
Dark Matter and 125 GeV Higgs for the IDM,
talk, 25th Rencontres de Blois: Particle Physics and Cosmology, 26 - 31 May 2013, Blois, France
2012
- P. Swaczyna, S. Grzedzielski,
Possible source of ENA fluxes from Galactic Center direction,
talk, 14th IBEX Science Team Meeting, 28 - 31 Mar. 2012, Bad Honnef, Germany
- S. Grzedzielski, M. Bzowski, J. M. Sokół, P. Swaczyna,
Observed H ENA and expected He ENA in the IBEX energy range: where are the sources?,
talk, 14th IBEX Science Working Team Meeting, 28 - 31 Mar. 2012, Bad Honnef, Germany
Unless stated otherwise, the posters and talks were presented by the first author.