Researcher Profile and Settings

Master

Affiliation (Master)

• Faculty of Science　Mathematics　Mathematics

Affiliation (Master)

• Faculty of Science　Mathematics　Mathematics

researchmap

Profile and Settings

Affiliation

• Hokkaido University, Faculty of Science, Associate Professor
• Hokkaido University, Graduate School of Science, Associate Professor
• Hokkaido University, Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Associate Professor

Degree

• Ph.D. in Science（Osaka University）
• M.Eng.（Osaka University）

Profile and Settings

• Name (Japanese)

  Tasaki

• Name (Kana)

  Sohei

• Name

  201201009024944388

Alternate Names

https://sohei-tasaki.github.io

Affiliation

• Hokkaido University, Faculty of Science, Associate Professor
• Hokkaido University, Graduate School of Science, Associate Professor
• Hokkaido University, Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Associate Professor

Achievement

Research Interests

• Model inference   Network inference   Sparse modeling   Data assimilation   Cluster analysis   Topological data analysis   Quantitative data analysis   Numerical analysis   Bifurcation theory   Variational method   Differential equations   Lipid bilayers   Shape memory alloys   Viscoelasticity   Phase separation   Phase transition   Non-equilibrium thermodynamics   Collective motion   Morphogenesis   Reprogramming   Epigenomes   Gene regulatory networks   Cellular diversity   Self-organization   Biofilms   Colony patterns   Bacillus subtilis   Pattern Formation   Data Analysis   Mathematical models   

Research Areas

• Life sciences / Bacteriology
• Life sciences / Developmental biology
• Life sciences / Biophysics
• Natural sciences / Bio-, chemical, and soft-matter physics
• Natural sciences / Applied mathematics and statistics
• Natural sciences / Basic mathematics

Research Experience

• 2021/07 - Today Hokkaido University Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science Associate Professor
• 2021/04 - Today Hokkaido University Graduate School of Science
• 2021/04 - Today Hokkaido University Faculty of Science Assistant Professor
• 2019/10 - 2021/03 RIKEN Center for Biosystems Dynamics Research (BDR) Research Scientist
• 2019/10 - 2021/03 Kyoto University Institute for the Advanced Study of Human Biology (ASHBi), Kyoto University Institute for Advanced Study (KUIAS), Kyoto University Assistant Professor
• 2018/05 - 2019/09 RIKEN Center for Biosystems Dynamics Research (BDR) Research Scientist
• 2018/04 - 2019/03 Sendai National College of Technology Education Coordinator
• 2013/04 - 2018/03 Tohoku University Graduate School of Science Assistant Professor (concurrent post)
• 2013/04 - 2018/03 Tohoku University Frontier Research Institute for Interdisciplinary Sciences (FRIS) Assistant Professor

Committee Memberships

• 2023/11 - Today   The Japan Society for Industrial and Applied Mathematics   学会誌「応用数理」主査（論文部門・チュートリアル部門・特集部門）
• 2023/04 - Today   National Institute of Science and Technology Policy, MEXT   専門調査員
• 2022/04 -2023/10   The Japan Society for Industrial and Applied Mathematics   学会誌「応用数理」編集委員（論文部門・チュートリアル部門）

Published Papers

• Numerical study of anisotropic diffusion in Turing patterns based on Finsler geometry modeling

  Gildas Diguet, Madoka Nakayama, Sohei Tasaki, Fumitake Kato, Hiroshi Koibuchi, Tetsuya Uchimoto

  Physical Review E 109 (1) 2470-0045 2024/01/10
• scEGOT: Single-cell trajectory inference framework based on entropic Gaussian mixture optimal transport

  Toshiaki Yachimura, Hanbo Wang, Yusuke Imoto, Momoko Yoshida, Sohei Tasaki, Yoji Kojima, Yukihiro Yabuta, Mitinori Saitou, Yasuaki Hiraoka

  2023/09/14 

  Abstract Time-series single-cell RNA sequencing (scRNA-seq) data have opened a door to elucidate cell differentiation processes. In this context, the optimal transport (OT) theory has attracted attention to interpolate scRNA-seq data and infer the trajectories of cell differentiation. However, there remain critical issues in interpretability and computational cost. This paper presents scEGOT, a novel comprehensive trajectory inference framework for single-cell data based on entropic Gaussian mixture optimal transport (EGOT). By constructing a theory of EGOT via an explicit construction of the entropic transport plan and its connection to a continuous OT with its error estimates, EGOT is realized as a generative model with high interpretability and low computational cost, dramatically facilitating the inference of cell trajectories and dynamics from time-series data. The scEGOT framework provides comprehensive outputs from multiple perspectives, including cell state graphs, velocity fields of cell differentiation, time interpolations of single-cell data, space-time continuous videos of cell differentiation with gene expressions, gene regulatory networks, and reconstructions of Waddington’s epigenetic landscape. To demonstrate that scEGOT is a powerful and versatile tool for single-cell biology, we applied it to time-series scRNA-seq data of the human primordial germ cell-like cell (human PGCLC) induction system. Using scEGOT, we precisely identified the PGCLC progenitor population and the bifurcation time of the segregation. Our analysis suggests that a known marker geneTFAP2Aalone is not sufficient to identify the PGCLC progenitor cell population, but thatNKX1-2is also required. In addition, we found thatMESP1andGATA6may also be crucial for PGCLC/somatic cell segregation.
• Nutrient-driven dedifferentiation of enteroendocrine cells promotes adaptive intestinal growth in Drosophila

  Hiroki Nagai, Luis Augusto Eijy Nagai, Sohei Tasaki, Ryuichiro Nakato, Daiki Umetsu, Erina Kuranaga, Masayuki Miura, Yuichiro Nakajima

  Developmental Cell 58 (18) 1 - 18 1534-5807 2023/09 [Refereed][Not invited]
  
• Migrating mesoderm cells self-organize into a dynamic meshwork structure during chick gastrulation

  Yukiko Nakaya, Mitsusuke Tarama, Sohei Tasaki, Ayako Isomura, Tatsuo Shibata

  2022/09/09 

  Abstract Migration of cell populations is a fundamental process in morphogenesis and disease. The mechanisms of collective cell migration of epithelial cell populations have been well studied. It remains unclear, however, how the highly motile mesenchymal cells, which migrate extensively throughout the embryo, are connected with each other and coordinated as a collective. During gastrulation in chick embryos, the mesoderm cells, that are formed by an epithelial-to-mesenchymal transition (EMT), migrate in the 3D space between ectoderm and endoderm of the embryo. Using live imaging and quantitative analysis, such as topological data analysis (TDA), we found that the mesoderm cells undergo a novel form of collective migration, in which they form a meshwork structure while moving away from the primitive streak. This meshwork is supported by N-cadherin-mediated cell-cell adhesion, which undergoes rapid reorganization. Overexpressing a mutant form of N-cadherin decreases the speed of tissue progression and the directionality of the collective cell movement, whereas the speed of individual cells remains unchanged. To investigate how this meshwork arises and how it contributes to the cell movement, we utilized an agent-based theoretical model, showing that cell elongation, cell-cell adhesion, and cell density are the key parameters for the meshwork formation. These data provide novel insights into how a supracellular structure of migrating mesenchymal cells forms and how it facilitates efficient migration during early mesoderm formation.
• All global bifurcation diagrams of stationary solutions to a phase field model

  Mori T, Tasaki S, Tsujikawa T, Yotsutani S

  Discrete and Continuous Dynamical Systems - Series B 1531-3492 2022/09 [Refereed][Not invited]
   

  <p style='text-indent:20px;'>We are concerned with bifurcation diagrams of stationary solutions to a phase field model proposed by Fix and followed by Caginalp. We show all the global bifurcation diagrams of stationary solutions to the model in the 1-dimension case. We see that bifurcation diagrams are surprisingly rich in variety depending on the latent heat and the initial total enthalpy. For instance, bifurcation diagrams include the secondary bifurcation point where symmetric breaking occurs, and curves which connect a limit of boundary layer solutions to the other limit of internal layer solutions.</p>

• Multicellular model of angiogenesis

  Takashi Nakazawa, Sohei Tasaki, Kiyohiko Nakai, Takashi Suzuki

  AIMS Bioengineering 9 (1) 44 - 60 2375-1495 2022/01 [Refereed]
   

  <abstract> <p>This paper presents a mathematical model governing the dynamics of a morphogenetic vascular endothelial cell (EC) during angiogenesis, and vascular growth formed by EC. Especially, we adopt a multiparticle system for modeling these cells. This model does not distinguish a tip cell from a stalk cell. A formed vessel is modeled using phase-field equation to prevent capillary expansion with time stepping in particular. Numerical simulation reveals that all cells are moving in the direction of high concentration of vascular endothelial growth factor (VEGF), and that they are mutually repellent in cases in which they are closer than some threshold.</p> </abstract>

• Time Changes in the VEGF-A Concentration Gradient Lead Neovasculature to Engage in Stair-Like Growth

  Yukinobu Ito, Dhisa Minerva, Sohei Tasaki, Makoto Yoshida, Takashi Suzuki, Akiteru Goto

  Springer Proceedings in Mathematics & Statistics 370 226 - 234 2194-1009 2021/08 [Refereed]
   

  Arteriovenous malformations consist of tangles of arteries and veins that are often connected by a fistula. The causes of and mechanisms underlying the development of these clinical entities are not fully understood. We previously reported a novel in vivo angiogenesis model as a useful disease model of arteriovenous malformation. With this model, the arterial graft was collected from the left carotid artery and sutured to the left jugular vein as a patchwork. The neovasculature extended from the branch of the subclavian artery toward the arterial graft. We measured the neovasculature, which had sprouted from arterioles, in the tissue samples. In the present study, we collected the arterial patch graft and adipose tissue surrounding the arterial graft and examined the distribution of the VEGF concentration by an enzyme-linked immunosorbent assay. At the area most distant from the arterial graft, the VEGF-A concentration changed over time in a sine wave pattern that gradually attenuated. A mathematical model was then constructed using the results, and a mathematical simulation of the neovasculature growth was performed. The new vessels grew in a stair-like pattern in this simulation, a result that matched those obtained through histological measurements.
• Cell population migration cycle and response to environmental pH in Bacillus subtilis

  Sohei Tasaki, Madoka Nakayama, Izumi Takagi, Jun-ichi Wakita, Wataru Shoji

  2020/09/11 

  Microbial populations are ubiquitous and some form a robust, multicellular structure called biofilm that protects the cells from environmental damage. The dispersion cycle is critical for controlling the population of important target microbes (both pathogenic and beneficial). Here, we show that the hysteresis of Bacillus subtilis cell-type regulation with respect to auto-inducing signal strength triggers the migration cycle of the cell population. We investigate migration cycle and its dependence on environmental conditions by quantitative analysis of cyclically expanding, concentric circular colonies. Next, we construct an input/output model that controls cell types in response to environmental conditions and signal density. On the basis of this model, we propose a migration cycle model for cell populations. The proposed model will widely predict biofilm-related phenomena and provide the basis for the description of highly self-regulating multicellular systems.
• Necessary and sufficient condition for hysteresis in the mathematical model of the cell type regulation of Bacillus subtilis

  Tasaki S, Nakayama M, Takagi I, Wakita J, Shoji W

  arXiv 2009.06524  2020/09 [Not refereed][Not invited]
  
• Morphological changes and their advantages in Bacillus subtilis colonies responding to environmental pH variation

  Tasaki S, Nakayama M, Shoji Y

  RIMS Kokyuroku 2087 24 - 30 2018/08 [Not refereed][Invited]
  
• Non-invasive force measurement reveals the number of active kinesins on a synaptic vesicle precursor in axonal transport regulated by ARL-8

  Kumiko Hayashi, Shin Hasegawa, Takashi Sagawa, Sohei Tasaki, Shinsuke Niwa

  Physical Chemistry Chemical Physics 20 (5) 3403 - 3410 1463-9076 2018/02/07 [Refereed][Not invited]
   

  Kinesin superfamily protein UNC-104, a member of the kinesin-3 family, transports synaptic vesicle precursors (SVPs). In this study, the number of active UNC-104 molecules hauling a single SVP in axons in the worm Caenorhabditis elegans was counted by applying a newly developed non-invasive force measurement technique. The distribution of the force acting on a SVP transported by UNC-104 was spread out over several clusters, implying the presence of several force-producing units (FPUs). We then compared the number of FPUs in the wild-type worms with that in arl-8 gene-deletion mutant worms. ARL-8 is a SVP-bound arf-like small guanosine triphosphatase, and is known to promote unlocking of the autoinhibition of the motor, which is critical for avoiding unnecessary consumption of adenosine triphosphate when the motor does not bind to a SVP. There were fewer FPUs in the arl-8 mutant worms. This finding indicates that a lack of ARL-8 decreased the number of active UNC-104 motors, which then led to a decrease in the number of motors responsible for SVP transport.
• Morphologies of Bacillus subtilis communities responding to environmental variation

  Sohei Tasaki, Madoka Nakayama, Wataru Shoji

  Development, Growth & Differentiation 59 (5) 369 - 378 0012-1592 2017/06 [Refereed][Invited]
  
• Self-organization of bacterial communities against environmental pH variation: Controlled chemotactic motility arranges cell population structures in biofilms

  Sohei Tasaki, Madoka Nakayama, Wataru Shoji

  PLOS ONE 12 (3) e0173195 - e0173195 1932-6203 2017/03 [Refereed][Not invited]
   

  As with many living organisms, bacteria often live on the surface of solids, such as foods, organisms, buildings and soil. Compared with dispersive behavior in liquid, bacteria on surface environment exhibit significantly restricted mobility. They have access to only limited resources and cannot be liberated from the changing environment. Accordingly, appropriate collective strategies are necessarily required for long-term growth and survival. However, in spite of our deepening knowledge of the structure and characteristics of individual cells, strategic self-organizing dynamics of their community is poorly understood and therefore not yet predictable. Here, we report a morphological change in Bacillus subtilis biofilms due to environmental pH variations, and present a mathematical model for the macroscopic spatiotemporal dynamics. We show that an environmental pH shift transforms colony morphology on hard agar media from notched `volcano-like' to round and front-elevated `crater-like'. We discover that a pH-dependent dose-response relationship between nutritional resource level and quantitative bacterial motility at the population level plays a central role in the mechanism of the spatio-temporal cell population structure design in biofilms.
• Environmental pH dependence of dense branching morphology-like colonies of Bacillus subtilis

  Nakayama M, Tasaki S, Shoji W

  RIMS Kokyuroku 1994 22 - 27 2016/04 [Not refereed][Not invited]
  
• Interactions in mixed lipid bilayers

  Tasaki S

  Mathematics for Industry 1 265 - 274 2014/07 [Refereed][Invited]
  
• Phase-separating elastic system of mixed lipid bilayers

  Sohei Tasaki

  PHYSICA D-NONLINEAR PHENOMENA 246 (1) 23 - 38 0167-2789 2013/03 [Refereed][Not invited]
   

  A phase-separating elastic system is studied to investigate the morphological dynamics in mixed lipid bilayers. The system can realize two kinds of interactions, elastic and trans-bilayer coupling. In the numerical simulations, even in simple situations with homogeneous and isotropic moduli, some characteristic intramembrane subdomain structures can be observed. The elastic interaction produces fine, distinctive morphology in the lipid membrane and the trans-bilayer coupling interaction regulates the symmetry of the two leaflets of the bilayer. On the basis of the numerical observation, some special states are formulated to simplify the system and to focus on the elastic interaction. Several mathematical properties of the resulting steady states are presented. In particular, it is proved that the elastic interaction stabilizes intramembrane subdomain structures by secondary bifurcations of the steady states. (C) 2012 Elsevier B.V. All rights reserved.
• Stationary solutions to a strain-gradient type thermoviscoelastic system

  Pawlow I, Suzuki T, Tasaki S

  Differential and Integral Equations 25 (3-4) 289 - 340 2012/12 [Refereed][Not invited]
  
• Hamilton formalism to compressible non-viscous fluid equations and application

  Murakami T, Suzuki T, Tasaki S

  NCTAM 59 105  2011/01 [Not refereed][Not invited]
  
• Stationary states and their stability in mathematical models of non-equilibrium thermodynamics

  Tasaki S

  Osaka University 1 - 131 2010/09 [Refereed][Not invited]
  
• Stationary solutions to a thermoelastic system on shape memory materials

  Suzuki T, Tasaki S

  Nonlinearity 23 (10) 2623 - 2656 2010/08 [Refereed][Not invited]
  
• Stationary solutions to the Falk system on shape memory alloys

  Suzuki T, Tasaki S

  Mathematical Methods in the Applied Sciences 33 (8) 994 - 1011 2010/05 [Refereed][Not invited]
  
• Stationary Fix-Caginalp equation with non-local term

  Suzuki T, Tasaki S

  Nonlinear Analysis 71 (3-4) 1329 - 1349 2009/05 [Refereed][Not invited]
  

Books etc

• 数理科学 2021年9月号 No. 699 数理モデリングと生命科学

  (Contributor枯草菌コロニーの形態形成モデル)
  サイエンス社 2021/08
• The Impact of Applications on Mathematics

  (Chapter 20)
  Springer Nature 2014/07

Presentations

• Multilevel concepts in bacterial cell populations  [Invited]

  Tasaki S

  7th Joint Conference of A3 Foresight Program on Computational and Applied Mathematics  2024/09  Wuhan University, Wuhan
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Tasaki S

  KSMB-SMB2024SEOUL  2024/07  Konkuk University, Seoul
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Tasaki S

  Turing Symposium on Morphogenesis, 2024 — a Panorama in Turing's Sight —  2024/02  Tohoku University, Sendai
• 最適輸送理論を用いた細胞分化の軌跡推定について

  Yachimura T, Imoto Y, Tasaki S, Hiraoka Y

  2023年度応用数学合同研究集会  2023/12
• バクテリアコロニー形成モデルの構築を目指して

  Murata R, Nagayama M, Tasaki S, Nakayama M

  2023年度応用数学合同研究集会  2023/12
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Tasaki S

  International Conference on Recent Developments of Theory and Methods in Mathematical Biology  2023/10  National Taiwan University
• Eigenpairs of the linear elasticity operator on the disk  [Not invited]

  Sohei Tasaki

  The Mathematical Society of Japan. Autumn Meeting 2023  2023/09
• 枯草菌の集団形態形成の実験と数理  [Invited]

  Sohei Tasaki

  札幌非線形現象研究会2023  2023/08
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Sohei Tasaki

  One-day workshop on pattern dynamics appearing in reaction-diffusion system  2023/08
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Sohei Tasaki

  10th International Congress on Industrial and Applied Mathematics (ICIAM2023)  2023/08
• Multilevel mathematical modeling methods for morphogenesis of bacterial cell populations  [Invited]

  Sohei Tasaki

  反応拡散系パターンダイナミクスの新展開  2023/06
• Mathematical analysis of dedifferentiation in the intestinal epithelial cell community

  Tasaki S, Nagai H, Nagai L, Nakato R, Miura M, Nakajima Y

  2023日本数学会年会  2023/03
• Mathematical analysis of dedifferentiation in the intestinal epithelial cell community

  Tasaki S, Nagai H, Nagai L, Nakato R, Umetsu D, Miura M, Nakajima Y

  2022年度応用数学合同研究集会  2022/12
• Secondary bifurcation and the direction of bifurcation of stationary solutions to a phase field model

  Tatsuki Mori, Sohei Tasaki, Tohru Tsujikawa, Shoji Yotsutani

  The Mathematical Society of Japan. Autumn Meeting 2022  2022/09
• Mathematical analysis of dedifferentiation in the intestinal epithelial cell community  [Invited]

  田崎 創平, 長井 広樹, ルイスアウグストエイジ ナガイ, 中戸 隆一郎, 三浦 正幸, 中嶋 悠一朗

  JSIAM 2022  2022/09
• Data assimilation of a cellular signal transduction system  [Invited]

  Sohei Tasaki

  JSIAM 2022  2022/09
• 腸管上皮細胞社会の数理モデル ー脱分化の役割と腸管増大の定量的解明ー

  Sohei Tasaki

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第4回若手ワークショップ  2022/01
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Sohei Tasaki

  The 22ND RIES-Hokudai International Symposium ‘癒’ [Yu]  2021/12
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Sohei Tasaki

  Modeling and Mathematical Analysis of Dynamics of Patterns  2021/10  Zoom Online Meeting
• Data assimilation of a cellular signal transduction system

  Tasaki S

  Hokkaido University PDE Seminar  2021/06
• Data assimilation of a cellular signal transduction system  [Invited]

  Tasaki S

  第5回マルチNGSオミクス解析研究会  2021/06
• Morphologies of Bacillus subtilis communities responding to environmental variation

  Tasaki S

  北海道大学理学研究院数学部門談話会  2021/05
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  117th HMMC Seminar  2021/05
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  第32回さいたま数理解析セミナー  2020/12
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  明治非線型数理セミナー・秋の学校  2020/11
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  MIMS Workshop "Mathematical Modellogy"  2020/11
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  JSPS Core-to-Core Program “Establishing International Research Network of Mathematical Oncology”  2020/10
• Multilevel life sciences by data assimilation  [Invited]

  Tasaki S

  JSMB2020  2020/09  Online Meeting
• A mathematical modeling approach to epigenetic dynamics  [Not invited]

  Tasaki S

  9th ASHBi Colloquium  2020/07  Zoom Online Meeting
• 細菌集団のライフサイクル  [Not invited]

  田﨑 創平

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第3回若手ワークショップ  2020/02  KKRホテル熱海
• 細胞のシグナル伝達系のデータ同化  [Not invited]

  田﨑 創平

  第16回生物数学の理論とその応用  2020/01  京都大学数理解析研究所
• 細菌集団のライフサイクル  [Not invited]

  田﨑 創平, 中山 まどか, 高木 泉, 東海林 亙

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第5回公開シンポジウム  2020/01  公益財団法人がん研究会
• 枯草菌の集団形態形成（第1部：細菌の細胞ダイバーシティー（講演と実演）、第2部：枯草菌の集団形態形成（講演））  [Invited]

  田﨑 創平

  2019年度第9回明治非線型数理セミナー  2020/01  明治大学生田キャンパス
• 枯草菌の集団形態形成  [Invited]

  田﨑 創平

  第79回京都駅前セミナー  2020/01  キャンパスプラザ京都
• 枯草菌の細胞タイプ制御の数理モデルとヒステリシスの条件  [Not invited]

  田﨑 創平, 中山 まどか, 高木 泉, 東海林 亙

  2019年度応用数学合同研究集会  2019/12  龍谷大学
• Mesoderm cells collectively migrate in the form of dynamic meshwork during chick gastrulation

  Nakaya U, Tasaki S, Isomura A, Shibata T

  The 42nd Annual Meeting of The Molecular Biology Society of Japan  2019/12  Fukuoka International Congress Center
• Life cycle of bacterial population  [Invited]

  Tasaki S

  Mathematics and Phenomena in Miyazaki (MPM) 2019  2019/11  Miyazaki University
• Morphologies of Bacillus subtilis communities  [Invited]

  Tasaki S

  17th Colloquium, Research Center for Mathematics and Data Science, Kwansei Gakuin University  2019/11  Kwansei Gakuin University
• Data assimilation simulation of a cellular signal transduction system  [Invited]

  Shibata T, Tasaki S

  29th Annual Meeting of the Japanese Society for Mathematical Biology (JSMB), 2019  2019/09  Tokyo Institute of Technology
• Dynamic self-organization of migrating mesoderm cell collective during chick gastrulation  [Invited]

  Tasaki S, Nakaya Y, Shibata T

  JSIAM Annual Meeting 2019  2019/09  The University of Tokyo
• Mesoderm cells collectively migrate in the form of dynamic meshwork during chick gastrulation  [Not invited]

  Nakaya Y, Tasaki S, Isomura A, Shibata T

  EMBO-EMBL Symposium: Mechanical Forces in Development  2019/07  EMBL, Heidelberg
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Not invited]

  Tasaki S

  西日本非線形研究会2019  2019/06  Kyushu University
• Challenge to uncover the mystery of meshwork structure of migrating mesoderm cell during chicken gastrulation  [Not invited]

  Nakaya Y, Tasaki S, Isomura A, Shibata T

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第4回公開シンポジウム  2019/06  RIKEN BDR
• Dynamic self-organization of migrating mesoderm cell collective  [Invited]

  Tasaki S

  第12回SaMPLセミナー・2019年度第3回広島大学数学科談話会  2019/06  Hiroshima University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  Modeling Biological Phenomena by Parabolic PDEs and their Analysis  2019/06  Renmin University of China
• Roles of N-cadherin mediated cell-cell contact in collective cell migration during chick mesoderm formation  [Not invited]

  Nakaya Y, Tasaki S, Isomura A, Shibata T

  52nd Annual Meeting of the Japanese Society of Developmental Biologists  2019/05  Osaka International House
• Morphologies of Bacillus subtilis communities  [Invited]

  Tasaki S

  第2回はこだて現象数理研究集会  2019/05  Future University Hakodate
• Necessary and sufficient condition for hysteresis in a mathematical model of cell type regulation of Bacillus subtilis  [Not invited]

  Tasaki S, Nakayama M, Takagi I, Shoji W

  The Mathematical Society of Japan. Annual Meeting 2019  2019/03  Tokyo Institute of Technology
• Challenge to uncover the mystery of meshwork structure of migrating mesoderm cell  [Not invited]

  Nakaya Y, Tasaki S, Isomura A, Shibata T

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第2回若手ワークショップ  2019/02
• Dynamic self-organization of migrating mesoderm cell collective  [Not invited]

  Tasaki S, Nakaya Y, Isomura A, Shibata T

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第2回若手ワークショップ  2019/02  仙台秋保 岩沼屋
• Morphologies of Bacillus subtilis communities responding to environmental variation and their multiscale modeling  [Not invited]

  Tasaki S, Nakayama M, Shoji Y

  JSDB Autumn Symposium 2018  2018/11  Okazaki Conference Center
• Challenge to uncover the mystery of meshwork structure of migrating mesoderm cell during chicken gastrulation  [Not invited]

  Nakaya Y, Tasaki S, Isomura A, Shibata T

  JSDB Autumn Symposium 2018  2018/11  Okazaki Conference Center
• 生命現象の解析〜「分かる」を形にする、「分からない」をあぶり出す  [Invited]

  Tasaki S

  データサイエンスが切り拓く生命科学・生体工学の未来  2018/09  Graduate School of Engineering Science, Osaka University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Not invited]

  Tasaki S

  Physical Biology Laboratory Seminar  2018/03  RIKEN CDB
• Morphologies and cellular diversity of Bacillus subtilis commuinities  [Not invited]

  Tasaki S

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第1回若手ワークショップ  2018/03  Hotel New Welcity Yugawara
• Morphologies and cellular diversity of Bacillus subtilis commuinities  [Not invited]

  Tasaki S

  新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第1回公開シンポジウム  2018/02  Graduate School of Engineering Science, Osaka University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  Theory of Biomathematics and its Applications XIV - Modelling and Analysis for Structured Population Dynamics and its Applications  2017/11  Masukawa Hall, Kyoto University
• 枯草菌の集団形態の予測と最適化  [Invited]

  Tasaki S

  土木工学とデータ科学の融合による土木構造物の革新的な健全度診断方法の開発  2017/10  Ito Campus, Kyushu University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Not invited]

  Tasaki S

  水戸数学・情報数理研究会2017  2017/08  水戸中央ビル
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  時空間ダイナミクス〜生命現象における時間変化を伴う空間秩序  2017/06  Nakano Campus, Meiji University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  第1回数理物理・統計力学セミナー  2017/05  Graduate School of Engineering, Tohoku University
• Self-organization of Bacillus subtilis communities responding to environmental pH variation  [Invited]

  Tasaki S

  拡散成分と非拡散成分が共存する反応拡散系がつくるパターン  2017/02  Kawai Hall, Tohoku University
• Self-organization of Bacillus subtilis communities responding to environmental pH variation  [Invited]

  Tasaki S

  数理科学と生体医工学  2016/09  Graduate School of Information Science, Tohoku University
• Morphologies of Bacillus subtilis communities responding to environmental variation  [Invited]

  Tasaki S

  The 2016 (26th) annual meeting of the Japanese Society for Mathematical Biology  2016/09  Shiiki Hall, Kyushu University
• Self-organization of microbial communities against environmental pH variation  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  Mathematical Approaches to Medical and Life Sciences  2016/06  Kawai Hall, Tohoku University
• 枯草菌集団の危機管理戦略と動態予測  [Invited]

  Tasaki S

  One day workshop 〜菌類に係るコロニーパターンの形成メカニズムの解明に向けて〜  2016/02  Faculty of Science, Chiba University
• Self-organization of microbial communities designed by dose-response relationships  [Invited]

  Tasaki S

  生物の動的集団の形成と制御  2015/10  Nakano Campus, Meiji University
• 生物の戦略的自己組織化とその予測  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  生物現象におけるパターン形成と数理  2015/10  RIMS, Kyoto University
• 数理モデルを用いた細菌コロニーの時空間成長予測  [Invited]

  Tasaki S

  第1回東北ドラッグデリバリーシステム研究会・第2回プラズマ遺伝子導入・治療機器研究会「生体システムの定量的解明に基づくドラッグデリバリーシステムの開発」  2015/08  Tohoku University
• Effective direction of bacterial activity 1: Big difference between "high-resistance" and "insensitivity" of bacteria to environmental pH variation  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  -Interdisciplinary Mathematics toward Smart Innovations- Mini-workshop on Models of Directional Movement and their Analysis  2015/03  Tohoku University
• Effective direction of bacterial activity 2: Spatio-temporal growth prediction of colonies self-organized by input-saturating positive feedback  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  -Interdisciplinary Mathematics toward Smart Innovations- Mini-workshop on Models of Directional Movement and their Analysis  2015/03  Tohoku University
• Growth prediction of colonies of motile bacteria  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  -Interdisciplinary Mathematics toward Smart Innovations- Mathematical Approaches to Pattern Formation  2014/10  Tohoku University
• Structure-preserving discretization  [Not invited]

  Tasaki S, Takagi I

  German-Japanese HeKKSaGOn Consortium Summer School @ Goettingen; Inference on Pattern Formation: Applications to Biology and Materials Science  2014/09  Goettingen University
• Practical introduction to numerical methods for diffusion equations  [Not invited]

  Takagi I, Tasaki S

  German-Japanese HeKKSaGOn Consortium Summer School @ Goettingen; Inference on Pattern Formation: Applications to Biology and Materials Science  2014/09  Goettingen University
• Prediction of motile bacterial colonies  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  German-Japanese HeKKSaGOn Consortium Summer School @ Goettingen; Inference on Pattern Formation: Applications to Biology and Materials Science  2014/09  Goettingen University
• Prediction of motile bacterial colonies  [Invited]

  Tasaki S, Nakayama M, Shoji Y

  Mini-workshop on Modeling, Simulation & Analysis of Pattern Formation  2014/07  Tohoku University
• Phase-separating elastic system of mixed lipid bilayers  [Invited]

  Tasaki S

  Forum "Math-for-Industry" 2013: The Impact of Applications on Mathematics  2013/11  Kyushu University
• Phase-separating elastic system of mixed lipid bilayers  [Invited]

  Tasaki S

  BioQuant Seminars  2013/09  BioQuant, Heidelberg University
• Interactions between heat, phase, deformation, chemical reaction, and biological movement  [Not invited]

  Tasaki S

  HeKKSaGOn Satellite Workshop  2013/09  Goettingen University
• 相分離弾性系とその分岐・安定性解析  [Invited]

  Tasaki S

  第6回 Math Mate セミナー  2013/04  AIMR, Tohoku University
• Phase-separating elastic system of mixed lipid bilayers  [Not invited]

  Tasaki S

  東北大学 SMART セミナー  2013/04  Tohoku University
• 混合脂質二重膜の相分離弾性系とその分岐・安定性解析  [Invited]

  Tasaki S

  第5回福島応用数学研究集会  2013/03  コラッセふくしま
• Second gradient energy-induced secondary bifurcations of steady states in phase-separating elastic systems  [Not invited]

  Tasaki S

  The 14th Northeastern Symposium on Mathematical Analysis  2013/02  Tohoku University
• Second gradient energy-induced secondary bifurcations of steady states in phase-separating elastic systems  [Not invited]

  Tasaki S

  Tohoku University Applied Mathematics Seminar  2012/10  Tohoku University
• Phase-separating elastic system of mixed lipid bilayers  [Not invited]

  Tasaki S

  第7回大阪大学非線形テクノサイエンス講演会  2012/02  Osaka University
• 混合脂質二重膜の相分離弾性系  [Invited]

  Tasaki S

  KSU Nonlinear Analysis Seminar  2012/02  Kyoto Sangyo University
• Phase-separating elastic system of mixed lipid bilayers  [Invited]

  Tasaki S

  京都駅前セミナー  2011/12  Campus Plaza Kyoto
• Stationary solutions to a strain-gradient type thermoviscoelastic system  [Invited]

  Tasaki S

  Analysis of non-equilibrium evolution problems: selected topics in material and life sciences  2011/11  Eindhoven University of Technology, Eindhoven, The Netherlands
• Formation and coarsening of microdomains in a mathematical model of mixed lipid bilayers  [Invited]

  Tasaki S

  Analysis of non-equilibrium evolution problems: selected topics in material and life sciences  2011/11  Eindhoven University of Technology, Eindhoven, The Netherlands
• ある歪み勾配型熱粘弾性系における定常状態とその安定性  [Invited]

  Tasaki S

  変分問題セミナー  2011/03  Tokyo Metropolitan University
• 生体膜上の側方拡散における曲率の効果  [Not invited]

  Saitou T, Tasaki S

  第6回大阪大学非線形テクノサイエンス講演会  2011/03  Osaka University Nakanoshima Center
• Mathematical Analysis of Microdomain Formation in Mixed Lipid Bilayer Membranes  [Not invited]

  Tasaki S, Saitou T

  第6回大阪大学非線形テクノサイエンス講演会  2011/03  Osaka University Nakanoshima Center
• Stationary states and their stability in a strain-gradient type thermoviscoelastic system  [Invited]

  Tasaki S

  第10回松山解析セミナー  2011/02  Ehime University
• Stationary states and their stability in a strain-gradient type thermoviscoelastic system  [Not invited]

  Tasaki S

  大阪市立大学数学研究所「複素解析セミナー」  2010/12  Osaka City University
• Stationary states and their stability in a strain-gradient type thermoviscoelastic system  [Invited]

  Tasaki S

  Regularity aspects of PDE - a week for Wojciech Zajaczkowski  2010/09  Bedlewo Conference Center, Polish Academy of Sciences, Poland
• Hamilton formalism to compressible non-viscous fluid equations and application  [Not invited]

  Murakami T, Suzuki T, Tasaki S

  The 59th NCTAM  2010/06  Science Council of Japan
• Pawlow's System on Thermoelastic Bodies with Shape Memory  [Not invited]

  Tasaki S

  第5回大阪大学非線形テクノサイエンス講演会  2010/03  Osaka University
• Stationary solutions to the Pawlow system on shape memory materials  [Not invited]

  Tasaki S

  The Mathematical Society of Japan. Annual Meeting 2010  2010/03  Keio University
• Stationary solutions to the Pawlow system on shape memory materials  [Not invited]

  Tasaki S

  Second Workshop on Mathematical Science and Nonlinear Partial Differential Equations  2010/02  Osaka University
• Stationary solutions to the Falk system on shape memory alloys  [Not invited]

  Tasaki S

  The Mathematical Society of Japan. Autumn Meeting 2009  2009/09  Osaka University
• Stationary Fix-Caginalp equation with non-local term  [Invited]

  Tasaki S

  京都駅前セミナー  2009/05  Campus Plaza Kyoto
• Stationary Solutions to the Falk System on Shape Memory Alloys  [Not invited]

  Tasaki S

  第4回大阪大学非線形テクノサイエンス講演会  2009/03  Osaka University
• Nonlocal eigenvalue problems in phase transition  [Not invited]

  Tasaki S

  Workshop on Mathematical Science and Nonlinear Partial Differential Equations  2009/02  Osaka University
• Stationary Fix-Caginalp equation with non-local term  [Invited]

  Tasaki S

  若手のための偏微分方程式と数学解析  2009/02  Kyushu University
• Stationary Fix-Caginalp equation with non-local term  [Invited]

  Tasaki S

  変分問題セミナー  2009/01  Tokyo Metropolitan University
• Stationary Fix-Caginalp equation with non-local term  [Invited]

  Tasaki S

  Workshop on Stationary Problems in Nonlinear Partial Differential Equations  2008/12  Kobe University
• Stationary Fix-Caginalp equation with non-local term  [Not invited]

  Tasaki S

  大阪大学数学教室微分方程式セミナー  2008/11  Osaka University
• Stationary Fix-Caginalp equation with non-local term  [Not invited]

  Tasaki S

  The Mathematical Society of Japan. Autumn Meeting 2008  2008/09
• Stationary Fix-Caginalp equation with non-local term  [Not invited]

  Tasaki S

  Third Euro-Japan Workshop on blow-up  2008/09  Tohoku University
• Steady states for the Falk model system of shape memory alloys  [Not invited]

  Tasaki S

  第3回大阪大学非線形テクノサイエンス講演会  2008/03  Senri Life Science Center
• Caginalp-Fix 方程式の定常問題  [Not invited]

  Tasaki S

  第30回上越教育大学における微分方程式セミナー  2007/08  Joetsu University of Education
• Stationary problems for non-isothermal phase transition models  [Not invited]

  Tasaki S, Suzuki T

  第2回大阪大学非線形テクノサイエンス講演会  2007/03  Senri Life Science Center

Teaching Experience

Exercises on Basic Mathematics C2Exercises on Basic Mathematics C2 Hokkaido University
Basic Mathematics C2Basic Mathematics C2 Hokkaido University
Mathematical Science BMathematical Science B Hokkaido University
Introductory CalculusIntroductory Calculus Hokkaido University
Calculus ICalculus I Hokkaido University
Advanced Mathematical AnalysisAdvanced Mathematical Analysis Hokkaido University
Analytic Studies (Nonlinear Mathematics)Analytic Studies (Nonlinear Mathematics) Hokkaido University
Calculus IICalculus II Hokkaido University
Calculus ICalculus I Hokkaido University
Analytic StudiesAnalytic Studies Hokkaido University
Advanced Mathematical AnalysisAdvanced Mathematical Analysis Hokkaido University
Calculus IICalculus II Hokkaido University
Exercises on Basic Mathematics A1Exercises on Basic Mathematics A1 Hokkaido University
Basic Mathematics A1Basic Mathematics A1 Hokkaido University
Linear Algebra ILinear Algebra I Hokkaido University
Linear Algebra IILinear Algebra II Hokkaido University
Lecture course (Developmental Biology/Cell Biology/Systems Biology)Lecture course (Developmental Biology/Cell Biology/Systems Biology) Kyoto University
Chemistry; Physics; MathematicsChemistry; Physics; Mathematics Sendai National College of Technology
Exercises in PhysicsExercises in Physics Tohoku University
Exercises in ElectromagnetismExercises in Electromagnetism Tohoku University
Fourier AnalysisFourier Analysis Tohoku University

Association Memberships

• THE MATHEMATICAL SOCIETY OF JAPAN   THE JAPAN SOCIETY FOR INDUSTRIAL AND APPLIED MATHEMATICS   

Research Projects

• Construction and analysis of a hybrid mathematical model describing the dynamics of bacterial cellular society

  JSPS：JSPS Kakenhi

  Date (from‐to) : 2023/04 -2026/03 

  Author : Sohei Tasaki
• Creation of multilevel model for predicting self-organization of bacterial population

  Japan Society for the Promotion of Science：Grant-in-Aid for Scientific Research (C)

  Date (from‐to) : 2019/04 -2023/03 

  Author : Tasaki S
• Integrated analysis and regulation of cellular diversity for disease treatment

  Ministry of Education, Culture, Sports, Science and Technology：Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

  Date (from‐to) : 2017/06 -2022/03 

  Author : Fujita N
• Prediction and control of biological self-organization dynamics

  Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University：Research Fellow Grant

  Date (from‐to) : 2013/04 -2018/03 

  Author : Tasaki S
• 数理解析による神経パターン形成機構の解明

  Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University：Program for Creation of Interdisciplinary Research

  Date (from‐to) : 2014/04 -2016/03 

  Author : Shoji W
• Stationary states and their stability in mathematical models of phase transition and shape memory materials

  Japan Society for the Promotion of Science：Grant-in-Aid for JSPS Research Fellows

  Date (from‐to) : 2010/04 -2012/03 

  Author : Tasaki S

   

  非平衡熱力学に現れる数理モデルの研究を行った.特に,申請者が形状記憶合金の数理モデルにおいて得ていた結果が普遍的に成り立つものであることを示した.そのために,形状記憶物質やポリマー物質を含む,広範な熱弾性体に関する熱力学的に矛盾のないシステムを構築した.このシステムにおいて,対象に応じて自由エネルギーおよび散逸ポテンシャルを適当に設定することでモデル方程式が導出される.この一般的なシステムにおいて,二つの双対的な変分構造があり,その間に安定性に関する比較構造が存在することを示した.この結果は例えば,保存系では温度ではなく保存量が定常状態の安定性を定めていることを意味しているが,各々のモデル方程式を分岐理論などを用いて詳しく解析していくときに応用することもできる重要なものである. 脂質二重膜における微小ドメインの形成は,生体膜においても重要な役割を担っていると考えられている.このような脂質二重膜内の形態を考察するため,相分離する弾性膜を記述するシステムを考え,数値計算および数学的解析を行った.弾性的相互作用が膜内ドメイン構造を作り,二層間相互作用が脂質組成の対称・非対称を制御している.適当に単純化したシステムを定式化し,得られる定常状態に関するいくつかの数学的性質を明らかにした.特に,定常解の二次分岐構造を提示し,この構造によって弾性的相互作用が膜内ドメイン構造を安定化していることを明らかにした.
• Analysis for nonlinear critical phenomena described by mean field equations

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2012 

  Author : SUZUKI Takashi, MISAWA Masashi, TAKAHASHI Futoshi, NAITO Yuki, OHTSUKA Hiroshi, SUGIYAMA Yoshie, ISHIWATA Michinori, KOBAYASHI Takayuki, NAWA Hayato, WATANABE Kazuo, SATO Tomohiko, MATSUMURA Akitaka, YAGI Atsushi, MISAWA Masashi, TAKAHASHI Futoshi, NAITO Yuki, OHTSUKA Hiroshi, SUGIYAMA Yoshie, KOBAYASHI Takayuki, NAWA Hayato, WATANABE Kazuo, SATO Tomohiko, MATSUMURA Akitaka, YAGI Atsushi, YOSHIKAWA Shuji, KUROKIBA Masaki, FURIHATA Daisuke, KUWATA Kazuhiro, TANAKA Mieko, YAMADA Yoshio, SAITO Norikazu, TAKAHASHI Ryo, TASAKI Sohei, RICCIARDI Tonia, STEVENS Angela, KAVALLARIS Nikos, PAWLOW Irena, CHAPLAIN Mark, QUARANTA Vito, CHAVANIS Pierre-henri

   

  Several common mathematical structures are found in the models describing the motion of mean field of many particles, point vortices, and so on. In this project we focused on a series of nonlinear partial differential equations provides with scaling invariance, and also variational structure associated with a variable regarded as field. We rigorously proved several phenomena emerged from the model, such as concentration or homeostasis, and at the same time developed new mathematical tools to approach interactions between species and global dynamics under strong nonlinearities

Social Contribution

• 令和５年度札幌啓成高校SSH事業 北海道大学研修（理学部数学科）「成長と増殖の数学」

  Date (from-to) : 2023/09/09-2023/09/09

  Role : Lecturer
• 「角度を変えないで写す」、「地図と折り紙」

  Date (from-to) : 2014/08/17-2014/08/19

  Role : Lecturer

  Sponser, Organizer, Publisher  : 主催：公益財団法人川井数理科学財団 協賛：ジブラルタ生命保険会社・東北大学大学院理学研究科

  Event, Program, Title : 第21回 〜高校生のための〜 仙台数学セミナー「複素数で遊ぶ」

  第21回高校生のための「仙台数学セミナー」にて講師を担当した。

Others

• 2022/01 -2022/01 [世話人] 新学術領域「細胞社会ダイバーシティーの統合的解明と制御」第4回若手ワークショップ
• 2020/12 -2020/12 [Organizer] 第43回日本分子生物学会年会 ワークショップ 1AW-11 「細胞運命ダイナミクスの定量的理解と操作の実現に向けて」
• 2020/09 -2020/09 [Organizing Committee] 2nd ASHBi Mathematical Biology Workshop
• 2015/04 -2018/03 [Organizer] Collaborative Mathematics Seminar (Tohoku University)
• 2014/04 -2018/03 [世話人] 全領域合同研究交流会（東北大学）
• 2013/04 -2018/03 [Steering Committee] Applied Mathematics Forum (Tohoku University)
• 2015/04 -2015/04 [Organizing Committee] International Conference “Frontiers in Mathematical Sciences”
• 2013/04 -2014/03 [世話人] 縦横無尽に階層・領域をまたぐ融合理工学セミナー（東北大学）
• 2013/03 -2013/03 [Organizing Committee] International Conference “Quantization Blow-up and Concentration in Mathematical Physics View Point”
• 2012/04 -2013/03 [Organizer] Applied Mathematics Seminar (Tohoku University)