Lipid Peroxidation Structure Selectivity: A Clue to Coal Workers' Pneumoconiosis

2024年5月30日(木) 16:00 - 17:00

Cai Tie (Associate Professor, China University of Mining and Technology, China)

Coal workers' pneumoconiosis (CWP), resulting from the inhalation of coal dust mixtures, is one of the leading occupational diseases globally. Despite its seriousness, there is still no effective curative method available for CWP. Therefore, a systemic understanding of CWP's pathogenesis is urgently needed. Peroxidation is an oxidation chain reaction in which lipids (glycerophospholipids and other membrane lipids) are degraded into excretory forms, such as fatty aldehydes. This process involves a series of enzymes that catalyze the reactions leading to lipid degradation. Our previous work identified specific regulatory mechanisms in lipid peroxidation processes triggered by diseases or various interventions. To gain a comprehensive understanding of lipid peroxidation, we developed a systematic profiling strategy that allows for the detailed observation of these oxidative processes. Additionally, we adapted this profiling strategy to investigate risk factors associated with coal workers' pneumoconiosis (CWP). By applying our methods to the study of CWP, we aimed to uncover the metabolic and molecular changes induced by coal dust inhalation, providing insights that could contribute to better prevention and treatment strategies for this occupational disease. To comprehensively investigate the lung alterations associated with CWP, both a cohort of coal miners and a CWP rat model were studied. Through the analysis of lipid peroxidation alterations associated with CWP occurrence, several CYP subtype-specific metabolic processes were identified. These findings suggest that coal-derived polycyclic aromatic hydrocarbons (PAHs) are major risk factors for CWP due to the specific activation of the Aryl Hydrocarbon Receptor (AhR) pathway. Further evidence at the gene level and morphological changes supports the role of coal-derived PAHs as key factors in the development of CWP. Hence, it is crucial to consider the toxicity induced by PAHs in the prevention and treatment of CWP.

会場: via Zoom

イベント公式言語: 英語

The New World of Spin Zero - Some Novel Approaches at QUP for Experimental Particle Cosmology -

2024年5月28日(火) 13:30 - 15:00

羽澄 昌史 (高エネルギー加速器研究機構 (KEK) 量子場計測システム国際拠点(QUP) 拠点長)

Particle cosmology is a discipline seeking a fundamental understanding of the Universe based on particle physics. Five mysteries drive our research today: cosmic inflation, baryon asymmetry, neutrino properties, dark matter, and dark energy. Resolving any of the five mysteries will revolutionize our picture of the Universe. Numerous interesting theoretical hypotheses have been proposed to this end. Many require new scalar quantum fields, such as inflatons, axions, supersymmetric particles, etc. They are, in a sense, an attempt to expand the role of the vacuum. Since we have not found such spin-zero fields yet, we shall invent new eyes to make an experimental or observational breakthrough. The International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP) was established in December 2021 at KEK under the WPI program of MEXT and JSPS. With its tagline of "bring new eyes to humanity," one of the primary missions of QUP is inventing and developing such new eyes for particle cosmology. In this seminar, after briefly introducing QUP, I focus on research topics I have contributed, including the LiteBIRD satellite to study inflatons and light scalar quantum field searches with novel methods using quantum sensing techniques.

会場: 大河内記念ホール / via Zoom

イベント公式言語: 英語

Introduction to homotopy theory

2024年5月24日(金) 15:00 - 17:00

小泉 淳之介 (数理創造プログラム 基礎科学特別研究員)

In a narrow sense, homotopy theory is a framework for capturing the essential structures of shapes and has long been used as a powerful tool in topology. On the other hand, the concept of homotopy is so universal that it appears even in purely algebraic settings and has recently had a significant impact on other fields such as number theory and algebraic geometry. This talk aims to introduce homotopy theory in this broader sense from multiple perspectives. If time permits, I will also touch upon recent developments in the homotopy theory of algebraic varieties.

会場: via Zoom / セミナー室 (359号室)

イベント公式言語: 英語

The collective order of human corneal endothelial cells as a unified biomarker for in vitro cultured cells and in vivo regenerated tissue

2024年5月23日(木) 16:00 - 17:00

山本 暁久 (数理創造プログラム 研究員)

Approximately 200,000 corneal transplantations are performed worldwide yearly, and more than half of them are applied to patients with corneal endothelial dysfunction. Recently, the restoration of functional corneas by injecting culture-expanded cells has developed in contrast to the conventional transplantation which relies on a limited number of donors’ corneas. This novel treatment opens up the potential to cure more patients with less surgical invasion and allows the utilization of cells with consistent and controlled quality. In this talk, I will introduce a unified physical biomarker for the quality assessment of corneal endothelial cells in in vitro culture and the predictive diagnosis of in vivo tissues using a single equation based on the collective order of cells. Taking an analogy to the two-dimensional colloidal assembly, the spatial arrangement of cells is generalized in terms of many-body interactions, and the “spring constant” of the underlying interaction potential is calculated from microscopy images. I also would like to discuss our recent approach to characterize the local structure of the arrangement of cells based on the topological data analysis.

会場: via Zoom

イベント公式言語: 英語

Prefactorization algebra and theta term

2024年5月21日(火) 16:00 - 17:30

川平 将志 (京都大学 基礎物理学研究所 博士課程)

Quantum field theories (QFTs) describe a lot of physical phenomena in our world. And giving a mathematical definition of QFTs is a long-standing problem. There are several mathematical formulations: Wightman formulation, Osterwalder–Schrader formulation and Atiyah-Segal formulation. And each of them cover different aspects of QFTs. Recently, Costello and their collabolators formulate QFTs by using prefactorization algbras. This formulaion cover a lot of classes of QFTs: TQFTs, 2d CFTs and perturbative QFTs. And they reproduce various results such as asymptotic freedom in non-Abelian gauge theories. Prefactorization algbras can be given by Batalin–Vilkovisky quantization (BV quantization) of the Lagrangian. However the original BV quantizations are perturbative and they do not have non-perturbative effects like instantons. In this talk, we propose the way to include Abelian-instanton effects. In modern language, it is the same as ℤgauging.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

iTHEMS-YITP Workshop: Bootstrap, Localization and Holography

2024年5月20日(月) - 24日(金)

会場: 京都大学基礎物理学研究所

イベント公式言語: 英語

Introduction to operator algebras

2024年5月17日(金) 15:00 - 17:00

北村 侃 (数理創造プログラム 基礎科学特別研究員)

I will give a quick introduction to operator algebras. Operator algebras in this talk consist of linear operators over some Hilbert space. Their study was initiated by Murray and von Neumann, motivated partially by the mathematical foundation of quantum mechanics. Starting from the definitions of a few basic notions, I will explain that commutative operator algebras can be interpreted as spaces. On the other hand, simple operator algebras (i.e., those without non-trivial ideals) form a class of operator algebras opposite to commutative ones and have attracted many operator algebraists. I will try to introduce several examples of simple operator algebras, some of which appear in mathematical physics. If time permits, I will also give recent results on ideals in C*-algebras. People with any scientific background are welcome.

会場: via Zoom / セミナー室 (359号室)

イベント公式言語: 英語

Exploring the impact of environments on flower color differentiation: A meta-analytical approach

2024年5月16日(木) 16:00 - 17:00

番場 大 (東北大学 大学院理学研究科 助教)

Flower color is one of the most diverse phenotypes in angiosperms, yet the initial processes of its differentiation remain unclear. Flower color is primarily expressed through the accumulation of pigment compounds in the petals, which are also associated with various stress responses. While it is conceivable that the environmental conditions during plant evolution could contribute to the differentiation of flower color, few studies have examined this hypothesis. Therefore, I conducted a meta-analysis using plant flower color information and growth environment data to elucidate the relationship between flower color differentiation and growth environments. Flower color data was extracted using LLM from botanical descriptions, and growth environment data was acquired by aligning GBIF occurrence information with WorldClim and ISRIC databases. Integrating approximately 30,000 flower color data points and 35 million occurrence records revealed trends such as a predominance of red flowers at higher altitudes and white flowers in arid areas. This study is still preliminary, so I would welcome discussions on more suitable analytical methods and models.

会場: via Zoom

イベント公式言語: 英語

Black hole graviton and quantum gravity

2024年5月16日(木) 15:00 - 16:30

木村 裕介 (理化学研究所 量子コンピュータ研究センター (RQC) 量子複雑性解析理研白眉研究チーム 研究員)

Drawing from a thought experiment that we conduct, we propose that a virtual graviton gives rise to a black hole geometry when its momentum surpasses a certain threshold value on the Planck scale. This hypothesis implies that the propagator of a virtual graviton, that possesses momentum surpassing this threshold, vanishes. Consequently, a Feynman diagram containing this type of graviton propagator does not add to the overall amplitude. This mechanism suggests the feasibility of formulating an ultraviolet-finite four-dimensional quantum gravitational theory. The elementary particles including the gravitons are treated as point particles in this formulation.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

Boundary-induced transitions in Möbius quenches of holographic BCFT

2024年5月15日(水) 16:00 - 17:30

Dongsheng Ge (大阪大学 大学院理学研究科 特任研究員)

Boundary effects play an interesting role in finite-size physical systems. In this work, we study the boundary-induced properties of 1+1-dimensional critical systems driven by inhomogeneous Möbius-like quenches. We focus on the entanglement entropy in BCFTs with a large central charge and a sparse spectrum of low-dimensional operators. We find that the choice of boundary conditions leads to different scenarios of dynamical phase transitions. We also derive these results in a holographic description in terms of intersecting branes in AdS3, and find a precise match.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

iTHEMS Cosmology Forum 1 - Cosmic Birefringence and Parity Violation in the Universe

2024年5月14日(火) 9:30 - 18:00

並河 俊弥 (東京大学 カブリ数物連携宇宙研究機構 (Kavli IPMU) 特任助教)
白石 希典 (公立諏訪東京理科大学 共通・マネジメント教育センター 准教授)
高橋 史宜 (東北大学 大学院理学研究科物理学専攻 教授)

iTHEMS Cosmology Forum Workshop is a series of short workshops, each focused on an emerging topics in cosmology. The targeted audience is cosmologists, high-energy physicists and astronomers interested in learning about the subject, not just those who have already worked on the topic. The goal of the workshop is to provide working knowledge of the topic and leave dedicated time for discussions to encourage mutual interactions among participants. The first workshop is devoted to cosmic birefringence, a newly establishing cosmological probe of the nature of our universe. Cosmic birefringence is the rotation of the linear polarization plane of the cosmic microwave background (CMB) radiation and, thanks to its origin, inherently measures the degree of parity violation in the cosmic history. This one-day workshop gathers both the observational and theoretical aspects of this growing topic. The workshop will be in English. The venue is on RIKEN Wako Campus, and the exact room is yet to be determined, depending on the number of registered participants. The workshops are organised by the iTHEMS Cosmology Forum working group, which is the successor of the Dark Matter Working Group at RIKEN iTHEMS. Important dates: 30th April - Registration deadline 14th May - Workshop Day Invited Speakers: Toshiya Namikawa (Kavli IPMU) Maresuke Shiraishi (Suwa University of Science) Fuminobu Takahashi (Tohoku University) Organisers: Kohei Hayashi, Nagisa Hiroshima, Derek Inman, Amaury Micheli, Ryo Namba

会場: 研究本館 4階 435-437号室

イベント公式言語: 英語

Nuclear Fusion and its Interdisciplinary Fields

2024年5月14日(火) 9:00 - 18:15

We will learn about nuclear fusion and related subjects, such as turbulence in astronomy and astrophysics, from experts and discuss possible interdisciplinary collaborations in the near future. Some researchers will visit RIKEN iTHEMS from the National Institute for Fusion Science (NIFS) and other universities and research institutes for the workshop. We will have the workshop in a hybrid style so that many researchers in Japan can hear the presentations even remotely. This workshop is supported by Moonshot Goal 10 (Program Director Yoshida Zensho (NIFS)). Program Session１ 9:00-9:35 (25+10: 25 mins for Presentation, 10 mins for Q&A)：Shinya Maeyama 9:35-10:10 (25+10): Naoki Sato 10:10-10:45 (25+10): Yohei Kawazura 10:45-11:15 Coffee Break Session２ 11:15-11:50 (25+10): Takanobu Amano 11:50-12:25 (25+10): Yosuke Matsumoto 12:25-13:00 (25+10): Akira Mizuta 13:00-14:00 Lunch Break Session３ 14:00-14:35 (25+10): Chiho Nonaka 14:35-15:10 (25+10): Takeo Hoshi 15:10-15:45 (25+10): Motoki Nakata 15:45-16:15 Coffee Break Session ４ 16:15-16:50 (25+10): Kumiko Hori 16:50-17:25 (25+10): Yutaka Ohira 17:25-18:00 (25+10): Camilia Demidem (TBC) 18:30-20:30: Dinner in the Main Research Building.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

Quantum Computing in Omics Medicine

2024年5月10日(金) 16:00 - 17:15

角田 達彦 (東京大学 大学院理学系研究科 生物科学専攻 教授)

(The speaker is also the team leader of Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Sciences. This is a joint seminar with the iTHEMS Biology Group.) In medical science, the recent explosive development of omics technologies has enabled the measurement not only of bulk data from entire tissues, but also data for individual cells and their spatial location information, and even allowed collection of such information in real-time. Meaningful interpretation of these rich data requires an ability to understand high-order and complex relationships that underpin biological phenomena such as drug response, simulating their dynamics, and selecting the optimal treatment for each patient based on these results. While these data are large-scale and of ultra-high dimensionality, they are also often sparse, with many missing values in the measurements and frequent higher-order interactions among variables, making them hard to handle with conventional statistics. To make further progress, machine learning – especially deep learning – is emerging as one of the promising ways forward. We have developed a method to transform omics data into an image-like representation for analysis with deep learning (DeepInsight) and have successfully used it to predict drug response and to identify original cell types from single-cell RNA-seq data. However, anticipation of the vast amount of medical data being accumulated gives particular urgency to addressing the problems of the time it actually takes to train deep learning models and the complexity of the necessary computational solutions. One possible way to resolve many of these problems is “quantum transcendence”, which is made possible by quantum superposition computation. Among all the different ways to apply quantum computation to medical science, we are particularly interested in quantum deep learning based on optimization and search problems, quantum modeling of single nucleotide detection by observational systems and statistical techniques such as regression analysis by inverse matrix computation and eigenvalue computation. In this seminar, I will first present an overview of how quantum machine learning and quantum deep learning can be used to formulate treatment strategies in medicine. We will discuss how to implement the quantum DeepInsight method, the challenges of noise in quantum computation when training QCNNs, feature mapping issues, problems of pretraining in quantum deep learning, and concerns relating to handling sensitive data such as genomic sequences. I hope this seminar will enhance our understanding of how to effectively facilitate medical research with quantum computing.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

Surrogate Modeling for Supernova Feedback toward Star-by-Star Simulations of Milky-Way-sized Galaxies

2024年5月10日(金) 14:00 - 15:15

Keiya Hirashima (東京大学 大学院理学系研究科 天文学専攻 博士課程)

Galaxy simulations have found the interdependence of multiscale gas physics, such as star formation, stellar feedback, inflow/outflow, and so on, by improving the physical models and resolution. The mass resolution remains capped at around 1,000 solar masses (e.g., Applebaum et al. 2021). To overcome the limitations, we are developing a new N-body/SPH code, ASURA-FDPS, to leverage exascale computing (e.g., Fugaku), handle approximately one billion particles, and simulate individual stars and stellar feedback within the galaxy. However, the emergence of communication costs hinders scalability beyond one thousand CPU cores. One of the causes is short timescale events localized in tiny regions, such as supernova explosions. In response, we have developed a surrogate model using machine learning to duplicate supernova feedback quickly (Hirashima et al., 2023a,b). In the presentation, I report the fidelity and progress of the simulations with our new machine-learning technique.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

Deep Learning for Estimating Two-Body Interactions in Mixed-Species Collective Motion

2024年5月9日(木) 16:00 - 17:00

上道 雅仁 (東京大学 大学院総合文化研究科 特任研究員)

(This is a joint seminar with the Information Theory Study Group.) Collective motion is a fundamental phenomenon observed in various biological systems, characterized by the coordinated movement of individual entities. Such dynamics are especially crucial in understanding cellular behaviors, which can now be observed at an individual level in complex tissue formations involving multiple types of cells, thanks to recent advancements in imaging technology. To harness this rich data and uncover the hidden mechanisms of such dynamics, we developed a deep learning framework that estimates equations of motion from observed trajectories. By integrating graph neural networks with neural differential equations, our framework effectively predicts the two-body interactions as a function of the states of the interacting entities. In this seminar, I will first introduce the structure and hyperparameters of our framework. Subsequently, I will detail two numerical experiments. The first is a simple toy model that was employed to generate data for testing our framework to refine the hyperparameters. The second explores a more complex scenario mimicking the collective motion of cellular slime molds, highlighting our model's ability to adapt to mixed-species interactions.

会場: 研究本館 3階 359号室とZoomのハイブリッド開催

イベント公式言語: 英語

Role of self-gravity on the central halo structure of fuzzy dark matter

2024年4月30日(火) 13:30 - 15:00

間仁田 侑典 (京都大学 基礎物理学研究所 協力研究員)

Fuzzy dark matter (FDM) is a dark matter model that is characterized by the ultralight masses around 10−22 eV. As FDM has the wave-like nature, the self-gravitating structure is described by the Schrödinger-Poisson equation. Previous simulations based on the Schrödinger-Poisson equation have demonstrated that soliton-like structure having a high-density flat core is formed at the central region of the FDM halos, and the size of such a core is typically determined by the de Broglie wavelength. Away from the central core, the density profile of the FDM halos resembles that of the cold dark matter halos on average, and is shown to be described by the Navarro-Frenk-White (NFW) profile. In this paper, we study the role of the self-gravity of the soliton core, and its relation to the bulk halo properties by solving the Schrödinger-Poisson equation in a simplified setup. The findings indicate that the contribution from the soliton self-gravity must dominate over the NFW potential in order to sustain the soliton.

会場: 研究本館 3階 359号室とZoomのハイブリッド開催

イベント公式言語: 英語

How Stars End Their Lives

2024年4月26日(金) 14:00 - 15:15

Philipp Podsiadlowski (Professor, University of Oxford, UK)

While the basic evolution of stars has been understood for many decades, there are still major uncertainties in our overall understanding of how stars end their lives, both in the context of low- and intermediate-mass stars (including the Sun) and massive stars. I will first review some of key principles that govern the structure and evolution of stars and then present recent progress that has been made for both groups of stars. I will argue and present numerical simulations that show that all stars become dynamically unstable when they become large giant stars, which leads to sporadic, dynamical mass ejections. Low- and intermediate-mass stars may lose all of their envelopes as a consequence, leaving white-dwarf remnants. More massive stars experience core collapse, leaving a neutron-star or black-hole remnant, possibly associated with a supernova explosion. I will show how the dramatic recent progress on understanding the core-collapse process, for the first time, allows us to connect the late evolution of massive stars with the resulting supernova explosions and the final remnants and discuss how observations with current gravitational-wave detectors (such as LIGO) will allow us to test this theoretical connection.

会場: セミナー室 (359号室) (メイン会場) / via Zoom

イベント公式言語: 英語

Tracing link of cell ageing and disease progression: Joining factors and facilitators

2024年4月25日(木) 16:00 - 17:00

ラジクマール・シング カルラ (沖縄科学技術大学院大学 (OIST) 免疫シグナルユニット 研究員)

Cell ageing is an inevitable biological process. It marks declined homeostatic processes in a cell, the impact of which is reflected in the organism’s function/physiology. Ageing, thus, raises risks of disease progression in elderly people and compromises their immunity. Progression of cancer and neurodegenerative diseases and weak immune response against a pathogen(s) represent cases of ageing-related diseases. What molecular factors/signaling could be associated with disease progression or take part in governing such decisions in aging? – remained a key focus of my research so far. In my talk, I shall shed light on the part characterizing key proteins and their signalling in ageing-related diseases with an emphasis on cancer, neurodegenerative disease, and immunity. Taking advantage of wet lab and system biology studying gene networks, and genomic, proteomic, and metabolomic readouts, I investigated the molecular expression and processes impacted and compromised by ageing. I shall be discussing new knowledge from my work on the linkage of cell ageing and disease progression and therein role of key factors and facilitators I studied.

会場: via Zoom

イベント公式言語: 英語

A night out with ghosts

2024年4月24日(水) 16:00 - 17:30

Veronica Errasti Diez (Research Fellow, Faculty of Physics, Ludwig-Maximilians-Universität München, Germany)

Field theories are the chief theoretical framework for physics. For instance, the Standard Model and General Relativity are widely accepted as accounting for subatomic particle and gravitational behavior, respectively. Nonetheless, even such acclaimed field theories have their limitations, such as the mysterious neutrino masses and dark sector. A natural and popular way around the hurdles consists in generalizations of field theories, via the inclusion of non-linear and/or higher-order corrections. Unless painstakingly avoided, these corrections lead to the propagation of negative kinetic energy modes, or ghosts for short. Ghosts have earned an appalling fame: kill, exorcise, avoid… No efforts are spared to guarantee their absence. In this talk, we will delve into the root causes for the ill name of ghosts. As a result, we will take up the cudgels for ghosts. While they do have a strong tendency to yield ill-behaved theories, ghosts are not intrinsically pathological. As we will see, good-natured ghosts open the door to multi-disciplinary tantalizing opportunities…! And ghosts make excellent party-goers, so make sure not to miss this appointment!

会場: 研究本館 3階 359号室とZoomのハイブリッド開催

イベント公式言語: 英語