---
_id: '14226'
abstract:
- lang: eng
  text: "We introduce the notion of a Faustian interchange in a 1-parameter family
    of smooth\r\nfunctions to generalize the medial axis to critical points of index
    larger than 0.\r\nWe construct and implement a general purpose algorithm for approximating
    such\r\ngeneralized medial axes."
alternative_title:
- ISTA Master's Thesis
article_processing_charge: No
author:
- first_name: Elizabeth R
  full_name: Stephenson, Elizabeth R
  id: 2D04F932-F248-11E8-B48F-1D18A9856A87
  last_name: Stephenson
  orcid: 0000-0002-6862-208X
citation:
  ama: Stephenson ER. Generalizing medial axes with homology switches. 2023. doi:<a
    href="https://doi.org/10.15479/at:ista:14226">10.15479/at:ista:14226</a>
  apa: Stephenson, E. R. (2023). <i>Generalizing medial axes with homology switches</i>.
    Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/at:ista:14226">https://doi.org/10.15479/at:ista:14226</a>
  chicago: Stephenson, Elizabeth R. “Generalizing Medial Axes with Homology Switches.”
    Institute of Science and Technology Austria, 2023. <a href="https://doi.org/10.15479/at:ista:14226">https://doi.org/10.15479/at:ista:14226</a>.
  ieee: E. R. Stephenson, “Generalizing medial axes with homology switches,” Institute
    of Science and Technology Austria, 2023.
  ista: Stephenson ER. 2023. Generalizing medial axes with homology switches. Institute
    of Science and Technology Austria.
  mla: Stephenson, Elizabeth R. <i>Generalizing Medial Axes with Homology Switches</i>.
    Institute of Science and Technology Austria, 2023, doi:<a href="https://doi.org/10.15479/at:ista:14226">10.15479/at:ista:14226</a>.
  short: E.R. Stephenson, Generalizing Medial Axes with Homology Switches, Institute
    of Science and Technology Austria, 2023.
date_created: 2023-08-24T13:01:18Z
date_published: 2023-08-24T00:00:00Z
date_updated: 2024-02-26T23:30:04Z
day: '24'
ddc:
- '500'
degree_awarded: MS
department:
- _id: GradSch
- _id: HeEd
doi: 10.15479/at:ista:14226
file:
- access_level: closed
  checksum: 453caf851d75c3478c10ed09bd242a91
  content_type: application/x-zip-compressed
  creator: cchlebak
  date_created: 2023-08-24T13:02:49Z
  date_updated: 2024-02-26T23:30:03Z
  embargo_to: open_access
  file_id: '14227'
  file_name: documents-export-2023-08-24.zip
  file_size: 15501411
  relation: source_file
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  checksum: 7349d29963d6695e555e171748648d9a
  content_type: application/pdf
  creator: cchlebak
  date_created: 2023-08-24T13:03:42Z
  date_updated: 2024-02-26T23:30:03Z
  embargo: 2024-02-25
  file_id: '14228'
  file_name: thesis_pdf_a.pdf
  file_size: 6854783
  relation: main_file
file_date_updated: 2024-02-26T23:30:03Z
has_accepted_license: '1'
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
page: '43'
publication_identifier:
  issn:
  - 2791-4585
publication_status: published
publisher: Institute of Science and Technology Austria
status: public
supervisor:
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
title: Generalizing medial axes with homology switches
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '10754'
abstract:
- lang: eng
  text: Targeting dysregulated Ca2+ signaling in cancer cells is an emerging chemotherapy
    approach. We previously reported that store-operated Ca2+ entry (SOCE) blockers,
    such as RP4010, are promising antitumor drugs for esophageal cancer. As a tyrosine
    kinase inhibitor (TKI), afatinib received FDA approval to be used in targeted
    therapy for patients with EGFR mutation-positive cancers. While preclinical studies
    and clinical trials have shown that afatinib has benefits for esophageal cancer
    patients, it is not known whether a combination of afatinib and RP4010 could achieve
    better anticancer effects. Since TKI can alter intracellular Ca2+ dynamics through
    EGFR/phospholipase C-γ pathway, in this study, we evaluated the inhibitory effect
    of afatinib and RP4010 on intracellular Ca2+ oscillations in KYSE-150, a human
    esophageal squamous cell carcinoma cell line, using both experimental and mathematical
    simulations. Our mathematical simulation of Ca2+ oscillations could fit well with
    experimental data responding to afatinib or RP4010, both separately or in combination.
    Guided by simulation, we were able to identify a proper ratio of afatinib and
    RP4010 for combined treatment, and such a combination presented synergistic anticancer-effect
    evidence by experimental measurement of intracellular Ca2+ and cell proliferation.
    This intracellular Ca2+ dynamic-based mathematical simulation approach could be
    useful for a rapid and cost-effective evaluation of combined targeting therapy
    drugs.
acknowledgement: "This work was partially supported by grants from National Institutes
  of Health (NIH) (R01 CA185055, S10OD0252300) and The University of Texas System
  STARs Award (to Z.P.),\r\nThe University of Texas at Arlington Interdisciplinary
  Research Program (to B.C., H.V.K. and Z.P.). "
article_number: '1763'
article_processing_charge: Yes
article_type: original
author:
- first_name: Yan
  full_name: Chang, Yan
  last_name: Chang
- first_name: Marah
  full_name: Funk, Marah
  last_name: Funk
- first_name: Souvik
  full_name: Roy, Souvik
  last_name: Roy
- first_name: Elizabeth R
  full_name: Stephenson, Elizabeth R
  id: 2D04F932-F248-11E8-B48F-1D18A9856A87
  last_name: Stephenson
  orcid: 0000-0002-6862-208X
- first_name: Sangyong
  full_name: Choi, Sangyong
  last_name: Choi
- first_name: Hristo V.
  full_name: Kojouharov, Hristo V.
  last_name: Kojouharov
- first_name: Benito
  full_name: Chen, Benito
  last_name: Chen
- first_name: Zui
  full_name: Pan, Zui
  last_name: Pan
citation:
  ama: Chang Y, Funk M, Roy S, et al. Developing a mathematical model of intracellular
    Calcium dynamics for evaluating combined anticancer effects of afatinib and RP4010
    in esophageal cancer. <i>International Journal of Molecular Sciences</i>. 2022;23(3).
    doi:<a href="https://doi.org/10.3390/ijms23031763">10.3390/ijms23031763</a>
  apa: Chang, Y., Funk, M., Roy, S., Stephenson, E. R., Choi, S., Kojouharov, H. V.,
    … Pan, Z. (2022). Developing a mathematical model of intracellular Calcium dynamics
    for evaluating combined anticancer effects of afatinib and RP4010 in esophageal
    cancer. <i>International Journal of Molecular Sciences</i>. MDPI. <a href="https://doi.org/10.3390/ijms23031763">https://doi.org/10.3390/ijms23031763</a>
  chicago: Chang, Yan, Marah Funk, Souvik Roy, Elizabeth R Stephenson, Sangyong Choi,
    Hristo V. Kojouharov, Benito Chen, and Zui Pan. “Developing a Mathematical Model
    of Intracellular Calcium Dynamics for Evaluating Combined Anticancer Effects of
    Afatinib and RP4010 in Esophageal Cancer.” <i>International Journal of Molecular
    Sciences</i>. MDPI, 2022. <a href="https://doi.org/10.3390/ijms23031763">https://doi.org/10.3390/ijms23031763</a>.
  ieee: Y. Chang <i>et al.</i>, “Developing a mathematical model of intracellular
    Calcium dynamics for evaluating combined anticancer effects of afatinib and RP4010
    in esophageal cancer,” <i>International Journal of Molecular Sciences</i>, vol.
    23, no. 3. MDPI, 2022.
  ista: Chang Y, Funk M, Roy S, Stephenson ER, Choi S, Kojouharov HV, Chen B, Pan
    Z. 2022. Developing a mathematical model of intracellular Calcium dynamics for
    evaluating combined anticancer effects of afatinib and RP4010 in esophageal cancer.
    International Journal of Molecular Sciences. 23(3), 1763.
  mla: Chang, Yan, et al. “Developing a Mathematical Model of Intracellular Calcium
    Dynamics for Evaluating Combined Anticancer Effects of Afatinib and RP4010 in
    Esophageal Cancer.” <i>International Journal of Molecular Sciences</i>, vol. 23,
    no. 3, 1763, MDPI, 2022, doi:<a href="https://doi.org/10.3390/ijms23031763">10.3390/ijms23031763</a>.
  short: Y. Chang, M. Funk, S. Roy, E.R. Stephenson, S. Choi, H.V. Kojouharov, B.
    Chen, Z. Pan, International Journal of Molecular Sciences 23 (2022).
date_created: 2022-02-13T23:01:35Z
date_published: 2022-02-01T00:00:00Z
date_updated: 2023-08-09T10:17:07Z
day: '01'
ddc:
- '510'
- '576'
department:
- _id: HeEd
doi: 10.3390/ijms23031763
external_id:
  isi:
  - '000754773500001'
file:
- access_level: open_access
  checksum: 8890ad20c54e90dc58ad5ea97c902998
  content_type: application/pdf
  creator: dernst
  date_created: 2022-02-14T07:46:30Z
  date_updated: 2022-02-14T07:46:30Z
  file_id: '10756'
  file_name: 2022_IJMS_Chang.pdf
  file_size: 24416183
  relation: main_file
  success: 1
file_date_updated: 2022-02-14T07:46:30Z
has_accepted_license: '1'
intvolume: '        23'
isi: 1
issue: '3'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
publication: International Journal of Molecular Sciences
publication_identifier:
  eissn:
  - '14220067'
  issn:
  - '16616596'
publication_status: published
publisher: MDPI
quality_controlled: '1'
scopus_import: '1'
status: public
title: Developing a mathematical model of intracellular Calcium dynamics for evaluating
  combined anticancer effects of afatinib and RP4010 in esophageal cancer
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 23
year: '2022'
...
---
_id: '11428'
abstract:
- lang: eng
  text: The medial axis of a set consists of the points in the ambient space without
    a unique closest point on the original set. Since its introduction, the medial
    axis has been used extensively in many applications as a method of computing a
    topologically equivalent skeleton. Unfortunately, one limiting factor in the use
    of the medial axis of a smooth manifold is that it is not necessarily topologically
    stable under small perturbations of the manifold. To counter these instabilities
    various prunings of the medial axis have been proposed. Here, we examine one type
    of pruning, called burning. Because of the good experimental results, it was hoped
    that the burning method of simplifying the medial axis would be stable. In this
    work we show a simple example that dashes such hopes based on Bing’s house with
    two rooms, demonstrating an isotopy of a shape where the medial axis goes from
    collapsible to non-collapsible.
acknowledgement: 'Partially supported by the DFG Collaborative Research Center TRR
  109, “Discretization in Geometry and Dynamics” and the European Research Council
  (ERC), grant no. 788183, “Alpha Shape Theory Extended”. Erin Chambers: Supported
  in part by the National Science Foundation through grants DBI-1759807, CCF-1907612,
  and CCF-2106672. Mathijs Wintraecken: Supported by the European Union’s Horizon
  2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement
  No. 754411. The Austrian science fund (FWF) M-3073 Acknowledgements We thank André
  Lieutier, David Letscher, Ellen Gasparovic, Kathryn Leonard, and Tao Ju for early
  discussions on this work. We also thank Lu Liu, Yajie Yan and Tao Ju for sharing
  code to generate the examples.'
article_processing_charge: No
author:
- first_name: Erin
  full_name: Chambers, Erin
  last_name: Chambers
- first_name: Christopher D
  full_name: Fillmore, Christopher D
  id: 35638A5C-AAC7-11E9-B0BF-5503E6697425
  last_name: Fillmore
- first_name: Elizabeth R
  full_name: Stephenson, Elizabeth R
  id: 2D04F932-F248-11E8-B48F-1D18A9856A87
  last_name: Stephenson
  orcid: 0000-0002-6862-208X
- first_name: Mathijs
  full_name: Wintraecken, Mathijs
  id: 307CFBC8-F248-11E8-B48F-1D18A9856A87
  last_name: Wintraecken
  orcid: 0000-0002-7472-2220
citation:
  ama: 'Chambers E, Fillmore CD, Stephenson ER, Wintraecken M. A cautionary tale:
    Burning the medial axis is unstable. In: Goaoc X, Kerber M, eds. <i>38th International
    Symposium on Computational Geometry</i>. Vol 224. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik; 2022:66:1-66:9. doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2022.66">10.4230/LIPIcs.SoCG.2022.66</a>'
  apa: 'Chambers, E., Fillmore, C. D., Stephenson, E. R., &#38; Wintraecken, M. (2022).
    A cautionary tale: Burning the medial axis is unstable. In X. Goaoc &#38; M. Kerber
    (Eds.), <i>38th International Symposium on Computational Geometry</i> (Vol. 224,
    p. 66:1-66:9). Berlin, Germany: Schloss Dagstuhl - Leibniz-Zentrum für Informatik.
    <a href="https://doi.org/10.4230/LIPIcs.SoCG.2022.66">https://doi.org/10.4230/LIPIcs.SoCG.2022.66</a>'
  chicago: 'Chambers, Erin, Christopher D Fillmore, Elizabeth R Stephenson, and Mathijs
    Wintraecken. “A Cautionary Tale: Burning the Medial Axis Is Unstable.” In <i>38th
    International Symposium on Computational Geometry</i>, edited by Xavier Goaoc
    and Michael Kerber, 224:66:1-66:9. LIPIcs. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2022. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2022.66">https://doi.org/10.4230/LIPIcs.SoCG.2022.66</a>.'
  ieee: 'E. Chambers, C. D. Fillmore, E. R. Stephenson, and M. Wintraecken, “A cautionary
    tale: Burning the medial axis is unstable,” in <i>38th International Symposium
    on Computational Geometry</i>, Berlin, Germany, 2022, vol. 224, p. 66:1-66:9.'
  ista: 'Chambers E, Fillmore CD, Stephenson ER, Wintraecken M. 2022. A cautionary
    tale: Burning the medial axis is unstable. 38th International Symposium on Computational
    Geometry. SoCG: Symposium on Computational GeometryLIPIcs vol. 224, 66:1-66:9.'
  mla: 'Chambers, Erin, et al. “A Cautionary Tale: Burning the Medial Axis Is Unstable.”
    <i>38th International Symposium on Computational Geometry</i>, edited by Xavier
    Goaoc and Michael Kerber, vol. 224, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2022, p. 66:1-66:9, doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2022.66">10.4230/LIPIcs.SoCG.2022.66</a>.'
  short: E. Chambers, C.D. Fillmore, E.R. Stephenson, M. Wintraecken, in:, X. Goaoc,
    M. Kerber (Eds.), 38th International Symposium on Computational Geometry, Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik, 2022, p. 66:1-66:9.
conference:
  end_date: 2022-06-10
  location: Berlin, Germany
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2022-06-07
date_created: 2022-06-01T14:18:04Z
date_published: 2022-06-01T00:00:00Z
date_updated: 2023-02-21T09:50:52Z
day: '01'
ddc:
- '510'
department:
- _id: HeEd
doi: 10.4230/LIPIcs.SoCG.2022.66
ec_funded: 1
editor:
- first_name: Xavier
  full_name: Goaoc, Xavier
  last_name: Goaoc
- first_name: Michael
  full_name: Kerber, Michael
  last_name: Kerber
file:
- access_level: open_access
  checksum: b25ce40fade4ebc0bcaae176db4f5f1f
  content_type: application/pdf
  creator: dernst
  date_created: 2022-06-07T07:58:30Z
  date_updated: 2022-06-07T07:58:30Z
  file_id: '11437'
  file_name: 2022_LIPICs_Chambers.pdf
  file_size: 17580705
  relation: main_file
  success: 1
file_date_updated: 2022-06-07T07:58:30Z
has_accepted_license: '1'
intvolume: '       224'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 66:1-66:9
project:
- _id: fc390959-9c52-11eb-aca3-afa58bd282b2
  grant_number: M03073
  name: Learning and triangulating manifolds via collapses
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '788183'
  name: Alpha Shape Theory Extended
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
publication: 38th International Symposium on Computational Geometry
publication_identifier:
  isbn:
  - 978-3-95977-227-3
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
series_title: LIPIcs
status: public
title: 'A cautionary tale: Burning the medial axis is unstable'
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 224
year: '2022'
...
---
_id: '12307'
abstract:
- lang: eng
  text: Point-set topology is among the most abstract branches of mathematics in that
    it lacks tangible notions of distance, length, magnitude, order, and size. There
    is no shape, no geometry, no algebra, and no direction. Everything we are used
    to visualizing is gone. In the teaching and learning of mathematics, this can
    present a conundrum. Yet, this very property makes point set topology perfect
    for teaching and learning abstract mathematical concepts. It clears our minds
    of preconceived intuitions and expectations and forces us to think in new and
    creative ways. In this paper, we present guided investigations into topology through
    questions and thinking strategies that open up fascinating problems. They are
    intended for faculty who already teach or are thinking about teaching a class
    in topology or abstract mathematical reasoning for undergraduates. They can be
    used to build simple to challenging projects in topology, proofs, honors programs,
    and research experiences.
article_processing_charge: No
article_type: original
author:
- first_name: Barbara A.
  full_name: Shipman, Barbara A.
  last_name: Shipman
- first_name: Elizabeth R
  full_name: Stephenson, Elizabeth R
  id: 2D04F932-F248-11E8-B48F-1D18A9856A87
  last_name: Stephenson
  orcid: 0000-0002-6862-208X
citation:
  ama: Shipman BA, Stephenson ER. Tangible topology through the lens of limits. <i>PRIMUS</i>.
    2022;32(5):593-609. doi:<a href="https://doi.org/10.1080/10511970.2021.1872750">10.1080/10511970.2021.1872750</a>
  apa: Shipman, B. A., &#38; Stephenson, E. R. (2022). Tangible topology through the
    lens of limits. <i>PRIMUS</i>. Taylor &#38; Francis. <a href="https://doi.org/10.1080/10511970.2021.1872750">https://doi.org/10.1080/10511970.2021.1872750</a>
  chicago: Shipman, Barbara A., and Elizabeth R Stephenson. “Tangible Topology through
    the Lens of Limits.” <i>PRIMUS</i>. Taylor &#38; Francis, 2022. <a href="https://doi.org/10.1080/10511970.2021.1872750">https://doi.org/10.1080/10511970.2021.1872750</a>.
  ieee: B. A. Shipman and E. R. Stephenson, “Tangible topology through the lens of
    limits,” <i>PRIMUS</i>, vol. 32, no. 5. Taylor &#38; Francis, pp. 593–609, 2022.
  ista: Shipman BA, Stephenson ER. 2022. Tangible topology through the lens of limits.
    PRIMUS. 32(5), 593–609.
  mla: Shipman, Barbara A., and Elizabeth R. Stephenson. “Tangible Topology through
    the Lens of Limits.” <i>PRIMUS</i>, vol. 32, no. 5, Taylor &#38; Francis, 2022,
    pp. 593–609, doi:<a href="https://doi.org/10.1080/10511970.2021.1872750">10.1080/10511970.2021.1872750</a>.
  short: B.A. Shipman, E.R. Stephenson, PRIMUS 32 (2022) 593–609.
date_created: 2023-01-16T10:07:21Z
date_published: 2022-05-28T00:00:00Z
date_updated: 2023-01-30T13:02:30Z
day: '28'
department:
- _id: HeEd
- _id: GradSch
doi: 10.1080/10511970.2021.1872750
intvolume: '        32'
issue: '5'
keyword:
- Education
- General Mathematics
language:
- iso: eng
month: '05'
oa_version: None
page: 593-609
publication: PRIMUS
publication_identifier:
  eissn:
  - 1935-4053
  issn:
  - 1051-1970
publication_status: published
publisher: Taylor & Francis
quality_controlled: '1'
scopus_import: '1'
status: public
title: Tangible topology through the lens of limits
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 32
year: '2022'
...
