News

12 news in 2022

2022-01-25

Seminar Report

NEW WG Seminar by Mr. Tomohiro Tanogami on January 20, 2022

Tomohiro Tanogami from Kyoto University gave a talk titled "A simple XY model for cascade transfer." Cascade transfer is a ubiquitous phenomenon that appears in various physical systems. During a cascade transfer an inviscid conserved quantity such as energy is transferred conservatively from large/small to small/large scales, which results in a universal scaling law in the spectrum (e.g., Kolmogorov energy spectrum). In the talk, Tomohiro proposed a simple XY model which shows inverse energy cascade with a non-Kolmogorov energy spectrum and pointed out that the model may characterize a novel "universality class" of cascade transfer. Tomohiro also explained possible relations between his model and, e.g., spin and atmospheric turbulences. About 20 physicists have joined the seminar and enjoyed discussions from various viewpoints. Reported by Hidetoshi Taya

2022-01-24

Press Release

Origin of Diverse Response Patterns in Signal Transduction - Determining Response Properties by Integrating Experiment and Theory

The ERBB family of receptors, consisting of ERBB1, ERBB2, ERBB3, and ERBB4, is a group of receptors that receive external signaling molecules. When the ERBB receptors receive signaling molecules, they bind to one another and induce phosphorylation reactions, leading to macroscopic responses such as cell proliferation and differentiation. However, it is difficult to measure the details of the binding and phosphorylation reactions of the ERBBs, and it has not been known how the various responses to signals are produced. In this study, we conducted experimental measurements using cells with various compositions of ERBBs and multiple signaling molecules and constructed a mathematical model, which incorporates all possible reactions of ERBBs. By applying the mathematical model, we succeed in explaining and predicting the experimental results on phosphorylation responses. Furthermore, we identified the reactions that play an essential role in the diversity of the phosphorylation responses. Our findings may allow us to control cell responses such as proliferation and differentiation in the future. For more details, please see the press release article from Kyoto University at RELATED LINKS.

2022-01-20

Event Schedule

Events for the 5th week of January 2022

Thursday, January 27, 10:00– 11:00 iTHEMS Biology Seminar Friday, January 28, 12:30- Coffee Meeting Saturday, January 29, 15:30- 16:40 RIKEN AIP-Suri-joshi Joint Seminar

2022-01-20

Seminar Report

iTHEMS Biology Seminar by Dr. Hiroyasu Miyazaki on January 20, 2022

In the iTHEMS Biology Seminar on 20th January, Dr. Hiroyasu Miyazaki (RIKEN iTHEMS) gave a talk on the topological aspect of chemical reaction network. His talk is composed of two parts: motivation and result part and method part. In the first part, he mentioned the reduction of the chemical reaction network in E. Coli and its result which shows the same steady state as that before the reduction. In the second part, he explained how the network should be reduced. The topological information of the network can be described by using the matrix and the vector. He explained that the quotient network is defined to have a sequence of linear maps called “exact sequence”, which describes the relation among the original network, the subnetwork and the quotient network. We enjoyed his beautiful talk. From the audiences, the lively discussion arose during and after the talk. Thank you very much, Hiroyasu! Reported by Hiroshi Yokota

2022-01-20

Paper of the Week

Week 4, January 2022

Title: Current-induced inverse symmetry breaking and asymmetric critical phenomena at current-driven tricritical point Author: Masataka Matsumoto, Shin Nakamura arXiv: http://arxiv.org/abs/2201.06894v1 Title: Global study of the scalar quasi-normal modes of Kerr-AdS${}_5$ black holes: Stability, thermality, and horizon area quantization Author: Issei Koga, Naritaka Oshita, Kazushige Ueda arXiv: http://arxiv.org/abs/2201.07267v1

2022-01-18

Seminar Report

DMWG Seinar by Dr. Kanji Mori on January 17, 2022

In this era of multi-messenger astronomy, axion-like particle (ALP) searches using astrophysical transients are now excitingly discussed. ALPs are an extended class of particles from QCD axion, which could solve the strong CP problem of the Standard Model, and dark matter (DM) candidates of various connections to the physics beyond the Standard Model. ALPs could interact with our sector through their coupling to the photon, electron, and/or nucleons. The coupling of ALP to the photon is previously investigated using observations of SN 1987A, the most famous supernova explosion. MeV gamma-ray signals are expected when considering the conversion of ALP outside the stellar envelope, hence no observations of the associated gamma-ray emission to the supernova lead to the constraint on the coupling strength, for example. Also, the existence of such coupling should modify the dynamics of supernovae. When a star explodes, the difference between the masses of the progenitor star and the resulting compact object sources the radiation, neutrino emission, and kinetic energy of the ejecta material. ALP could be an additional channel for the energy release while its absorption heats the supernova. The balance between heating and cooling controls the supernova dynamics and shock restoration, which directly relates to the electromagnetic observables. Dr. Mori has shown that the heating rate is very sensitive to the coupling strength and enhancement of the electromagnetic emission is expected in the pre-supernova stage. The signatures could also be visible in the neutrino sector after the explosion. The results are fantastic, and there are a lot of things to do. For example, the inclusion of the ALP-nucleon coupling effects is an interesting direction to pursue. Updates in the understanding of stellar models are important as well. We should see the signature of ALP in the near future in this field! Reported by Nagisa Hiroshima

2022-01-17

Seminar Report

iTHEMS Biology Seminar by Dr. Wataru Nishima on January 13, 2022

Dr. Wataru Nishima (New Mexico Consortium, USA) gave a very interesting presentation about his published paper on the spike protein of the SARS-CoV-2, the virus which causes COVID-19 [1]. He described the conformational change which the SARS-CoV-2 spike protein undergoes when it fuses with the host cell to initiate infection. His work offers and interesting alternative view of the process wherein parts of the spike protein ends up inside the host cell. This differs from the usual view where the spike protein would be left on the outside of the cell after virus fusion with the host. This alternative hypothesis could have important implication for better understanding disease severity, e.g. based on the possible toxic effect of spike protein components shed as part of the fusion process. Dr. Nishima's expertise is primarily in Molecular Dynamics and Bioinformatics and he is very interested to establish new collaborations with iTHEMS members. Reported by Catherine Beauchemin

2022-01-17

Hot Topic

Reading the World through the Window of Math Focusing on the Sensitivity of Young Researchers

A column article about "Reading the World through the Window of Math" appeared on Imagineer Co., Ltd. Ten Minutes TV. The article is based on the co-authored book "Reading the World through the Window of Math: Exploring Prime Numbers, AI, Biology, and the Universe" (edited by Tetsuo Hatsuda and Ryosuke Shibato, Iwanami Shoten), which was written by young researchers from iTHEMS. Please see the related link for details.

2022-01-14

Research News

RIKEN NEWS: Uncovering the laws of evolution hidden in genomic information

Senior Research Scientist Jeffrey Fawcett is interviewed on the RIKEN website. Life on Earth has been around for about 4 billion years. Over the years, organisms have evolved into a wide variety of species. This is also the history of how the genomes have evolved. Jeffrey Fawcett (Senior Research Scientist, iTHEMS) is trying to unravel the mystery of how the differences between species arose by taking a mathematical science approach. To read more, please see the related link.

2022-01-13

Paper of the Week

Week 3, January 2022

Title: Biexciton-like quartet condensates in an electron-hole liquid Author: Yixin Guo, Hiroyuki Tajima, Haozhao Liang arXiv: http://arxiv.org/abs/2201.03031v1 Title: Optimized Two-Baryon Operators in Lattice QCD Author: Yan Lyu, Hui Tong, Takuya Sugiura, Sinya Aoki, Takumi Doi, Tetsuo Hatsuda, Jie Meng, Takaya Miyamoto arXiv: http://arxiv.org/abs/2201.02782v1 Title: A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs Author: James O. Chibueze, et al.; H.E.S.S. Collaboration (Naomi Tsuji) arXiv: http://arxiv.org/abs/2201.00069v1 Title: Analyticity of the energy in an Ising spin glass with correlated disorder Author: Hidetoshi Nishimori Journal Reference: J. Phys. A 55, 045001 (2022) doi: https://doi.org/10.1088/1751-8121/ac44ef arXiv: http://arxiv.org/abs/2110.01196v2 Title: The hyperon spectrum from lattice QCD Author: Nolan Miller, Grant Bradley, M. A. Clark, Ben Hörz, Dean Howarth, Malcolm Lazarow, Henry Monge-Camacho, Amy Nicholson, Enrico Rinaldi, Pavlos Vranas, André Walker-Loud arXiv: http://arxiv.org/abs/2201.01343v1 Title: A path integral derivation of the equations of anomalous Hall effect Author: Kazuo Fujikawa, Koichiro Umetsu arXiv: http://arxiv.org/abs/2201.01104v1 Title: Gravitational wave asteroseismology on cooling neutron stars Author: Hajime Sotani, Akira Dohi arXiv: http://arxiv.org/abs/2201.00648v1 Title: Non-Equilibrating a Black Hole with Inhomogeneous Quantum Quench Author: Kanato Goto, Masahiro Nozaki, Kotaro Tamaoka, Mao Tian Tan, Shinsei Ryu arXiv: http://arxiv.org/abs/2112.14388v1 Title: Chaos by Magic Author: Kanato Goto, Tomoki Nosaka, Masahiro Nozaki arXiv: http://arxiv.org/abs/2112.14593v1 Title: Cooling of Isolated Neutron Stars with Pion Condensation: Possible Fast Cooling in a Low-Symmetry-Energy Model Author: Akira Dohi, Helei Liu, Tsuneo Noda, Masa-aki Hashimoto arXiv: http://arxiv.org/abs/2112.13302v1 Title: Dynamical stability and filamentary instability in holographic conductors Author: Shuta Ishigaki, Shunichiro Kinoshita, Masataka Matsumoto arXiv: http://arxiv.org/abs/2112.11677v2

2022-01-13

Event Schedule

Events for the 4th week of January 2022

Monday, January 17, 11:00– 12:00 DMWG Seminar Thursday, January 20, 10:00– 11:00 iTHEMS Biology Seminar Thursday, January 20, 13:30– 15:00 NEW WG Seminar Friday, January 21, 12:30- Coffee Meeting

2022-01-12

Seminar Report

iTHEMS Biology Seminar by Prof. Tetsuya Yamamoto on January 6, 2022

On January 6th, Prof. Tetsuya Yamamoto gave us a comprehensive talk about the physical aspects of nuclear bodies. He first introduced the liquid-liquid phase separation and other self-assembly mechanisms in soft-matter physics, such as micelle formation, with motivations from the experimental side. In the main part, he told us about three recent topics regarding how RNAs' dynamics and sequence properties lead to different types of assembly of nuclear bodies. The mathematical formulation, schematic figures, and comparisons with experiments were clear to understand. We are very grateful to Prof. Yamamoto for the exciting seminar. Reported by Kyosuke Adachi

12 news in 2022