研究者紹介システム

桑村 雅隆
クワムラ マサタカ
大学院人間発達環境学研究科 人間環境学専攻
教授
自然科学関係
Last Updated :2022/01/10

研究者情報

所属

  • 【主配置】

    大学院人間発達環境学研究科 人間環境学専攻
  • 【配置】

    国際人間科学部 環境共生学科, 発達科学部 人間環境学科

学位

  • 博士(理学), 広島大学

授業科目

ジャンル

  • 科学・技術 / 数学

コメントテーマ

  • 応用解析学
  • コンピュータシミュレーション
  • 微分方程式

研究活動

研究キーワード

  • 数値シミュレーション
  • 非線形現象
  • 微分方程式

研究分野

  • 自然科学一般 / 応用数学、統計数学
  • 自然科学一般 / 数学基礎

受賞

  • 2009年09月 日本応用数理学会, 日本応用数理学会論文賞, Japan Journal of Industrial and Applied Mathematics, vol 25, pp.281-303 (2008) に掲載された論文

    桑村 雅隆

論文

  • Dynamics of localized unimodal patterns in reaction-diffusion systems for cell polarization by extracellular signaling

    Masataka Kuwamura, Sungrim Seirin-Lee, Shin-ichiro Ei

    2018年, SIAM Journal on Applied Mathematics, 78 (6), 3238 - 3257, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masataka Kuwamura, Hirofumi Izuhara

    We study the diffusion-driven destabilization of a spatially homogeneous limit cycle with large amplitude in a reaction-diffusion system on an interval of finite size under the periodic boundary condition. Numerical bifurcation analysis and simulations show that the spatially homogeneous limit cycle becomes unstable and changes to a stable spatially nonhomogeneous limit cycle for appropriate diffusion coefficients. This is analogous to the diffusion-driven destabilization (Turing instability) of a spatially homogeneous equilibrium. Our approach is based on a reaction-diffusion system with mass conservation and its perturbed system considered as an infinite dimensional slow-fast system (relaxation oscillator). Published by AIP Publishing.

    AMER INST PHYSICS, 2017年03月, CHAOS, 27 (3), 012908, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Turing instabilities in prey-predator systems with dormancy of predators

    Masataka Kuwamura

    2015年, Journal of Mathematical Biology, 71, 125 - 149, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Perturbations and dynamics of reaction-diffusion systems with mass conservation

    Masataka Kuwamura, Yoshihisa Morita

    2015年, Physical Review E, 92, 012908, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Stability of Coexisting Equilibrium of Prey-Predator Systems with Dormancy of Predators

    Masataka Kuwamura

    In this paper, we study the stability of a coexistence equilibrium in a prey-predator system with dormancy of predators. The results suggest that dormancy of predators can stabilize the population dynamics of prey-predator systems if the switch to predators entering dormancy is very sharp or if both the hatching and mortality rates of dormant predators are sufficiently low.

    KOBE UNIV, DEPT MATHEMATICS, 2014年08月, FUNKCIALAJ EKVACIOJ-SERIO INTERNACIA, 57 (2), 339 - 350, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masataka Kuwamura, Kousuke Maeda, Takashi Adachi-Yamada

    The Drosophila posterior midgut epithelium mainly consists of intestinal stem cells (ISCs); semi-differentiated cells, i.e. enteroblasts (EBs); and two types of fully differentiated cells, i.e. enteroendocrine cells (EEs) and enterocytes (ECs), which are controlled by signalling pathways. In [M. Kuwamura, K. Maeda, and T. Adachi-Yamada, Mathematical modeling and experiments for the proliferation and differentiation of Drosophila intestinal stem cells I, J. Biol. Dyn. 4 (2009), pp. 248-257], on the basis of the functions of the Wnt and Notch signalling pathways, we studied the regulatory mechanism for the proliferation and differentiation of ISCs under the assumption that the Wnt proteins are supplied from outside the cellular system of ISCs. In this paper, we experimentally show that the Wnt proteins are specifically expressed in ISCs, EBs, and EEs, and theoretically show that the cellular system of ISCs can be self-maintained under the assumption that the Wnt proteins are produced in the cellular system of ISCs. These results provide a useful basis for determining whether an environmental niche is required for maintaining the cellular system of tissue stem cells.

    TAYLOR & FRANCIS LTD, 2012年, JOURNAL OF BIOLOGICAL DYNAMICS, 6 (2), 267 - 276, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masataka Kuwamura, Kousuke Maeda, Takashi Adachi-Yamada

    The Drosophila posterior midgut epithelium mainly consists of intestinal stem cells (ISCs); semi-differentiated cells, i.e. enteroblasts (EBs); and two types of fully differentiated cells, i.e. enteroendocrine cells (EEs) and enterocytes (ECs), which are controlled by signalling pathways. In [M. Kuwamura, K. Maeda, and T. Adachi-Yamada, Mathematical modeling and experiments for the proliferation and differentiation of Drosophila intestinal stem cells I, J. Biol. Dyn. 4 (2009), pp. 248-257], on the basis of the functions of the Wnt and Notch signalling pathways, we studied the regulatory mechanism for the proliferation and differentiation of ISCs under the assumption that the Wnt proteins are supplied from outside the cellular system of ISCs. In this paper, we experimentally show that the Wnt proteins are specifically expressed in ISCs, EBs, and EEs, and theoretically show that the cellular system of ISCs can be self-maintained under the assumption that the Wnt proteins are produced in the cellular system of ISCs. These results provide a useful basis for determining whether an environmental niche is required for maintaining the cellular system of tissue stem cells.

    TAYLOR & FRANCIS LTD, 2012年, JOURNAL OF BIOLOGICAL DYNAMICS, 6 (2), 267 - 276, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Takefumi Nakazawa, Masataka Kuwamura, Norio Yamamura

    In this study, we numerically investigated to what extent introducing resting-egg dynamics would stabilize simple Daphnia-algae consumer-resource models. In the models, the density of viable resting eggs was explicitly expressed, and we assumed that zooplankton produced resting eggs seasonally or in response to food deficiency and that resting eggs hatched seasonally. The models predicted that, although the paradox of enrichment was not completely resolved (i.e., the system was destabilized by eutrophication), we found the following conditions under which the stabilizing effects of resting eggs would be significantly large: (1) resting eggs are produced seasonally (rather than in response to food deficiency), (2) the annual average allocation ratio to resting eggs is large, and (3) the annual average hatching rate of resting eggs is low. The results suggest that resting-egg dynamics can significantly reduce the paradox of enrichment within the biologically meaningful parameter space and contribute to the stability of plankton community dynamics.

    SPRINGER TOKYO, 2011年04月, POPULATION ECOLOGY, 53 (2), 341 - 350, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masataka Kuwamura, Takefumi Nakazawa

    In this paper, a simple model is used to demonstrate that the dormancy of predators dependent on the rate of decline in the prey density can strongly stabilize the population dynamics of prey-predator systems. This result may help explain why the population dynamics of phytoplankton-zooplankton (-resting eggs) is frequently observed to be strongly stable in nature. Moreover, it is numerically shown that the model can have two stable prey-predator cycles with different amplitudes and periods, which suggests that prey-predator (-dormant predator) systems have the potential to generate multiple stable cycles without any other mechanism.

    SIAM PUBLICATIONS, 2011年, SIAM JOURNAL ON APPLIED MATHEMATICS, 71 (1), 169 - 179, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Masataka Kuwamura, Takefumi Nakazawa, Toshiyuki Ogawa

    In this paper, a mathematical model of a prey-predator system is proposed to resolve the paradox of enrichment in ecosystems. The model is based on the natural strategy that a predator takes, i.e, it produces resting eggs in harsh environment. Our result gives a criterion for a functional response, which ensures that entering dormancy stabilizes the population dynamics. It is also shown that the hatching of resting eggs can stabilize the population dynamics when the switching between non-resting and resting eggs is sharp. Furthermore, the bifurcation structure of our model suggests the simultaneous existence of a stable equilibrium and a large amplitude cycle in natural enriched environments. © 2008 Springer-Verlag.

    2009年03月, Journal of Mathematical Biology, 58 (3), 459 - 479, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Mixed-mode oscillations and chaos in a prey-predator system with dormancy of predators

    Masataka Kuwamura, Hayato Chiba

    2009年, Chaos, , vol. 19, 043121, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Deviation from the predicted wavenumber in a mode selection problem for the Turing patterns

    Masataka Kuwamura

    2008年, Japan Journal of Industrial and Applied Mathematics, , vol. 25, pp.281-303, 英語

    [査読有り]

    研究論文(学術雑誌)

  • The Hamiltonian formalism in reaction-diffusion systems

    Masataka Kuwamura

    2007年, Advanced Studies in Pure Mathematics, , vol. 47, pp.635-646, 英語

    [査読有り]

    研究論文(学術雑誌)

  • 散逸系のパターン形成問題に現れるハミルトン形式

    桑村 雅隆

    2006年03月, 応用数理, vol.16 No.1, 17-26, 日本語

    [査読有り]

    研究論文(学術雑誌)

  • Krein's formula for indefinite multipliers in linear periodic Hamiltonian systems

    Masataka Kuwamura, Eiji Yanagida

    2006年, Journal of Differential Equations, , vol. 230, pp.446-464, 英語

    [査読有り]

    研究論文(学術雑誌)

  • M Kuwamura

    In this article, fundamental properties concerning the Turing patterns are considered in one-dimensional dissipative systems with gradient/skew-gradient structure introduced in [ M. Kuwamura and E. Yanagida, Phys. D, 175 ( 2003), pp. 185 - 195]. It is a natural extension of free energy, which covers reaction-diffusion systems of activator-inhibitor type. The theory based on this concept provides a new perspective on a fundamental problem of what unique Turing pattern is to be selected among many.

    SIAM PUBLICATIONS, 2005年, SIAM JOURNAL ON APPLIED MATHEMATICS, 65 (2), 618 - 643, 英語

    [査読有り]

    研究論文(学術雑誌)

  • A variational approach to singular perturbation problems in reaction-diffusion systems

    Shin-ichiro Ei, Masataka Kuwamura, Yoshihisa Morita

    2005年, Physica D, , vol.207, pp.171-219, 英語

    [査読有り]

    研究論文(学術雑誌)

  • The Eckhaus and zigzag instability criteria in gradient/skew-gradient dissipative systems

    M Kuwamura, E Yanagida

    The concept of gradient/skew-gradient structure-an extension of free energy-is introduced. In dissipative systems with this structure, the Eckhaus and zigzag instability criteria can be represented in terms of first integral and free energy per unit length for steady states. Moreover, an exact relation between these criteria is presented. These results are valid for steady states of arbitrary profile and amplitude, which implies that the instability criteria are valid for steady states far from threshold. Furthermore, our results support the marginal stability hypothesis for roll solutions in the wavenumber selection problem in gradient systems. The derivation for the results is simple and rigorous. (C) 2002 Elsevier Science B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2003年02月, PHYSICA D-NONLINEAR PHENOMENA, 175 (3-4), 185 - 195, 英語

    [査読有り]

    研究論文(学術雑誌)

  • A perspective of renormalization group approaches

    Masataka Kuwamura

    2001年, Japan Journal of Industrial and Applied Mathematics, , vol.18, pp.739-768, 英語

    [査読有り]

    研究論文(学術雑誌)

  • The stability of roll solutions of the two-dimensional Swift-Hohenberg equation and the phase-diffusion equation

    M Kuwamura

    A stability criterion of roll solutions of the two-dimensional Swift-Hohenberg equation is presented. It clarifies the effect of the system size on the primary instabilty of rolls. An interpretation of the phase-diffusion equation is also given from the viewpoint of spectral analysis. The key to carrying out the spectral analysis is that the infinite-dimensional system of linear equations naturally induced by the Fourier decomposition for the linearized eigenvalue problem of the roll solution can be reduced to the three-dimensional system.

    SIAM PUBLICATIONS, 1996年09月, SIAM JOURNAL ON MATHEMATICAL ANALYSIS, 27 (5), 1311 - 1335, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Phase dynamics method with applications to the Swift-Hohenberg equation

    Masataka Kuwamura

    1994年, Journal of Dynamics and Differential Equations, , vol.6, pp.185-225, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Very slow dynamics for some reaction-diffusion system with activator-inhibitor type

    Masataka Kuwamura, Shin-ichiro Ei, Masayasu Mimura

    1992年, Japan Journal of Industrial and Applied Mathematics, , vol.9, pp.35-77, 英語

    [査読有り]

    研究論文(学術雑誌)

MISC

  • ハミルトン構造とパターン形成

    桑村 雅隆

    2005年04月, 物性研究, vol.84 No.1, 2-21, 日本語

    記事・総説・解説・論説等(学術雑誌)

書籍等出版物

  • 応用解析概論

    桑村 雅隆

    単著, 裳華房, 2018年11月, 日本語

    教科書・概説・概論

  • 線形代数学入門

    桑村 雅隆

    単著, 裳華房, 2016年02月, 日本語

    教科書・概説・概論

  • パターン形成と分岐理論

    桑村 雅隆

    単著, 共立出版, 2015年01月, 日本語

    学術書

  • 微分積分入門

    桑村 雅隆

    単著, 裳華房, 2008年11月, 日本語

    教科書・概説・概論

講演・口頭発表等

  • 細胞極性化に関連する微分方程式の解の性質について

    明治大学MIMS共同研究集会「幾何学・連続体力学・情報科学の交差領域の探索」, 2020年12月

  • 保存量をもつ反応拡散系における特異摂動の例について

    桑村雅隆

    OCAMI共同研究「反応拡散方程式と非線形分散型方程式の解の挙動」, 2020年02月, 日本語

    口頭発表(一般)

  • Dynamics of localized patterns in reaction-diffusion systems for cell polarization by extracellular signaling

    桑村 雅隆

    The 43rd Sapporo Symposium on Partial Differential Equations, 2018年08月, 英語, 国際会議

    [招待有り]

    口頭発表(招待・特別)

  • 保存量をもつ反応拡散系におけるパルス状局在解の挙動について

    桑村 雅隆, 李 聖林, 栄 伸一郎

    2017年度応用数学合同研究集会, 2017年12月, 日本語, 国内会議

    口頭発表(一般)

  • Diffusion driven destabilization of a spatially homogeneous limit cycle in reaction-diffusion systems

    桑村 雅隆

    JSMB2016, 2016年09月, 英語, Fukuoka, Japan, 国際会議

    口頭発表(一般)

  • Conservation breaking dynamics in reaction-diffusion systems

    桑村 雅隆

    ICIAM2015, 2015年08月, 英語, Beijing, China, 国際会議

    口頭発表(一般)

  • 捕食者の休眠を伴う prey-predator 系に現れるTuring 不安定性について

    桑村 雅隆

    生物数学の理論とその応用, 2014年09月, 日本語, 京都大学数理解析研究所, 国内会議

    口頭発表(一般)

  • Turing patterns in prey-predator systems with dormancy of predators

    Masataka Kuwamura

    3rd Italian-Japanese workshop on geometric properties for parabolic and elliptic PDE's, 2013年09月, 英語, Tokyo, 国際会議

    口頭発表(一般)

  • Dormancy of predators in prey-predator systems

    Masataka Kuwamura

    The 7th East Asia SIAM Conference, 2011年06月, 英語, Waseda University, Kitakyushu Campus, 国際会議

    口頭発表(一般)

  • Mathematical modeling and experiments for the proliferation and differentiation of Drosophila intestinal stem cells

    Masataka Kuwamura, Kousuke Maeda, Takashi Adachi-Yamada

    The second China-Japan Colloquim of Mathematical Biology, 2008年08月, 英語, Okayama University, 国際会議

    口頭発表(一般)

  • 散逸系におけるパターン選択問題について

    桑村 雅隆

    日本数学会春期応用数学分科会特別講演, 2004年, 日本語, 日本数学会, 筑波,, 国内会議

    [招待有り]

    口頭発表(招待・特別)

所属学協会

  • SIAM

  • 日本数学会

共同研究・競争的資金等の研究課題