PREYING on PLANTS How Parasites Target Healthy Vegetation

SUMMER 2021

SHOWCASING THE BEST OF JAPAN’S PREMIER RESEARCH ORGANIZATION • www.riken.jp/en/ PREYING ON PLANTS How parasites target healthy vegetation

UPPING THE ANTI New physics possibilities from classic device

DRAWING ON DATA AI provides answers in a crisis

HAIR TODAY, HAIR TOMORROW Stem cells regenerate follicle growth ▲ Bigger fish to fry A RIKEN-led team has developed larger strains of zooplankton by creating mutations with a heavy-ion beam. Bigger versions of this important feed stock for fish nurseries could improve fish farming efficiencies and help supply the needs of a growing global population (see page 16).

ADVISORY BOARD

RIKEN, Japan’s flagship publication is a selection For further information on the BIOLOGY ARTIFICIAL INTELLIGENCE research institute, conducts of the articles published research in this publication or • Kuniya Abe (BRC) • Hiroshi Nakagawa (AIP) basic and applied research in by RIKEN at: https://www. to arrange an interview with a • Makoto Hayashi (CSRS) • Satoshi Sekine (AIP) a wide range of fields riken.jp/en/news_pubs/ researcher, please contact: • Shigeo Hayashi (BDR) including physics, chemistry, research_news/ RIKEN International • Joshua Johansen (CBS) PHYSICS medical science, biology Please visit the website for Affairs Division • Atsuo Ogura (BRC) • Akira Furusaki (CEMS) and engineering. recent updates and related 2-1, Hirosawa, Wako, • Yasushi Okada (BDR) • Hiroaki Minamide (RAP) articles. Articles showcase Saitama, 351-0198, Japan • Hitoshi Okamoto (CBS) • Yasuo Nabekawa (RAP) Initially established RIKEN’s groundbreaking Tel: +81 48 462 1225 • Kensaku Sakamoto (BDR) • Shigehiro Nagataki (CPR) as a private research results and are written for a Fax: +81 48 463 3687 • Kazuhiro Sakurada (R-IH) • Masaki Oura (RSC) foundation in Tokyo in 1917, non-specialist audience. [email protected] • Harukazu Suzuki (IMS) • Toru Tamagawa (RNC) RIKEN became a national • Toshitada Takemori (IMS) • Tomohiro Uesaka (RNC) research and development RIKEN Research is published ISSN 1883-3519 • Koji Yonekura (RSC) • Yasunori Yamazaki (CPR) institute in 2015. by RIKEN in collaboration www.riken.jp/en with Nature Research CHEMISTRY COMPUTER / RIKEN Research is an online Custom Media, a part • Hideki Abe (CSRS) COMPUTATIONAL SCIENCE and print publication that of Springer Nature. • Keisuke Tajima (CEMS) • Toshiaki Iitaka (ISC) highlights the best research • Katsunori Tanaka (CPR) • Takahito Nakajima (R-CCS) published by RIKEN. This • Hirofumi Tomita (R-CCS) © FRANK FOX / SCIENCE PHOTO LIBRARY TABLE OF CONTENTS

Editorial Infographic Quantum questions 3 Calling all 8 The new RIKEN Center for Quantum collaborators Computing (RQC) is co-ordinating the Japanese-government's quantum agenda, and exploring a number of important People approaches for qubits, quantum circuits 4 and quantum architecture. Physics modeling of viral spread between cells Catherine Beauchemin Deputy Program Director

Managing a marmoset brain atlas Alexander Woodward Research Unit leader 10 highlights 10 Revealing the origins of skyrmion lattices Briefs 11 Glycans play crucial role 6 in COVID-19 infection Gene database 12 Choreographing the RIKEN protects cherry downward dance of blossoms plant roots 13 Giant pulses have gigantic BDR Symposium levels of energy

RNA diagnostic test for 14 New way to create COVID-19 faster than particles for quantum current PCR detection computers predicted p.13 Virtual open day 15 Bringing inductors down to size Japan’s new quantum headquarters 16 Supersized snacks for growing fish

17 Chemical reaction zips along at water surface

18 A new drug target for schizophrenia p.15

SUMMER 2021 1 TABLE OF CONTENTS

Research COVER STORY 19 highlights Feature 26 Hunting for big game in physics with a small trap: An instrument designed to probe 19 Mysterious magnetar may power bright the imbalance between matter and antimatter binary star could make the search for axions much, much more affordable. 20 Unfertilized egg modifications key to some traits

21 Organic make-up of planetary systems differs from early on

22 Alpha particles lurk at the surface of neutron-rich nuclei

COVER STORY 23 Parasitic plants make their point with ethylene

24 Quantum nanodevice can simultaneously do work and cool Perspectives COVER STORY 30 AI of the storm: During the pandemic, RIKEN’s artificial COVER STORY intelligence teams have been able to advance everything from 25 Regenerating hair travel advice to online medicine. Has COVID-19 unlocked in the lab Japan’s big data doors?

p.21

2 RIKEN RESEARCH EDITORIAL

Calling all collaborators

Hidetoshi Kotera Executive Director, RIKEN

ne of our goals in publishing and of our research to society in the form of innovation. distributing this magazine is to provide For this, we work with universities and research SUMMER 2021 SHOWCASING THE BEST OF JAPAN’S PREMIER RESEARCH ORGANIZATION • www.riken.jp/en/ information with the potential to institutes, as well as with a number of companies in PREYING stimulate new collaborations between the private sector. ON PLANTS How parasites target ORIKEN and partners around the world. Today, I We have seen many positive results from such healthy vegetation would like to update our readers on some exciting collaborations, including the establishment of a new

developments regarding our collaborations. research organization, the Interdisciplinary Theo- UPPING THE ANTI New physics possibilities from classic At RIKEN, our collaborations are now managed retical and Mathematical Sciences Program, based device

DRAWING ON DATA by a new organization called the Science, Technol- on collaboration between RIKEN, Kyoto University, AI provides answers in a crisis

HAIR TODAY, ogy, and Innovation Hub. As the name implies, it and research groups in China, India and the United HAIR TOMORROW Stem cells regenerate is meant to act as a hub for collaborations. One States. Another collaboration with Hiroshima Uni- follicle growth of its functions is to promote collaboration inside versity has furthered cell-imaging technologies and RIKEN, through initiatives such as our Engineering one with Nagoya University has led to the devel- COVER STORY: The invasive organs Network, which brings together people working opment of a new rice strain that is currently being (pictured) of parasitic on joint research projects beyond each discipline. evaluated in Kenya. We are looking to expand these plants, such as Phthei- Another important function is to promote projects networks to many more universities and companies rospermum japonicum, between RIKEN researchers and other institutes outside of Japan. respond to the plant and universities. We hope that you will find examples of research hormone ethylene. Page 23 The basic method we use to find collaborators is in this issue of RIKEN Research that will lead to to analyze the fields where we have strengths, and future collaborations. © 2021 RIKEN then identify partners that we can work with to enable us to pioneer new research fields, nurture young scientists, and ultimately return the results

Keep up to date

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SUMMER 2021 3 PEOPLE

infected cell sees the same amount of virus as one that is far away. In my Physics modeling first research project I constructed a simple, spatial model for the spread of a respiratory virus infection to of viral spread show how local effects impact cell- to-cell virus spread, and the immune response. There was very little known about SARS-CoV-1 at that time, so I between cells decided to construct my first model based on the influenza virus. I didn’t Catherine Beauchemin know that influenza would become Deputy Program Director, RIKEN Interdisciplinary Theoretical important due to the possibility of an avian influenza pandemic, which and Mathematical Sciences (iTHEMS) program remains a threat today.

Describe your role at RIKEN mathematical models to explain the I first joined RIKEN in 2016 as a senior experimental observations made when I construct visiting scientist at iTHES, the prede- viruses infect cell cultures. In biology, cessor of the Interdisciplinary Theo- such knowledge is usually advanced computer models to retical and Mathematical through experimental trial and error, explain the observations Sciences (iTHEMS) but physics modeling can help program. In 2020, streamline this process. made when viruses infect I became one cell cultures. of four iTHEMS How did you become deputy program interested in your field? directors. I am As an undergraduate in My research is important to in a field I call computational physics, I society because… ‘virophysics’; became interested in self- Let’s say we want to determine the time the applica- organizing systems and between giving two doses of a vaccine tion of physics distributed intelligence. As a to confer optimal protection. In immunol- methods to virology. graduate student, I intended to ogy or virology, this is done by testing Primarily, I construct work on social insect behavior, different dosing intervals in as many computer and but my doctoral advisor wanted people as possible, and then we can me to work with him on cancer. choose only from the options that were He gave me a paper called tested. Without equations, we cannot Immunology for physicists. predict what happens if the interval is Reading it, I became longer or shorter, because the system is fascinated by how our complex and the response is nonlinear. immune system learns My research is developing physics- about new pathogens based equations that accurately predict and retains that what happens between and beyond the memory over a long scenarios tested. time. Coincidentally, this happened around How has being at RIKEN helped 2003, when the your research? original SARS virus The iTHEMS program was designed to (SARS-CoV-1) hit stimulate interdisciplinary collaborations. China, Canada and There are many seminars on topics other countries. ranging from physics to biology and The mathemati- mathematics to information theory. We cal models in have informal, iTHEMS-wide seminars the papers I was and coffee meetings on many of these reading always topics. At these meetings, new ideas and assumed that a perspectives emerge, and we exchange

4 RIKEN RESEARCH PEOPLE

of software we use to do this is called ANTs (Advanced Normalization Tools). Managing a We also use popular deep-learning libraries such as TensorFlow and PyTorch, and have recently been marmoset looking at how to use artificial intelligence running through web browsers. We have also been leveraging a high- performance computing cluster to batch brain atlas process thousands of brain images.

What has been your most Alexander Woodward memorable experience at RIKEN? Unit leader, Connectome Analysis Unit, I have fond memories of traveling, which RIKEN Center for Brain Science has often been linked to the Interna- tional Neuroinformatics Coordinating Facility (INCF). ■ Describe your role at RIKEN Neuroinformatics Unit. Before that I I lead a group that is a member of completed a post-doc at the University Careers at RIKEN Japan’s Brain/MINDS project that of Tokyo with Takashi Ikegami. The lab For further information, focuses specifically on the brain of the there focused on complex systems and visit our Careers page: common marmoset. My group works on artificial life. Website: www. neuroinformatics applied to digital brain riken.jp/en/ atlases and online database develop- How has being at RIKEN helped careers ment. One of our current focuses is your research? E-mail: pr@ riken.jp upgrading a digital marmoset brain atlas Being able to interact with RIKEN’s that we previously developed for world-class researchers in neurosci- Brain/MINDS. ence has definitely helped further Digital atlases are important to large- my understanding of the brain. Addi- scale brain-mapping projects because tionally, working at RIKEN has meant you need a common digital space for we have always been able to get the integrating and organizing data from computer equipment we need. Being diverse experiments in 3D. Marmoset a core part of Japan’s Brain/MINDS research has also become quite active project has also expanded in recent years, due to what it can my network within reveal about human brain structure and the neuroscience function. Other activity from our group community. includes the work of Rui Gong, who has worked on how to improve atlas con- What struction using artificial intelligence, and are some Takuto Okuno, who has developed a technologies new method for causal analysis of func- you use? tional brain networks where different We are always regions are defined by a brain atlas. processing and mapping How did you become interested in datasets your current research? on to one I studied computer vision at the Uni- another or versity of Auckland, New Zealand. A on to brain big focus was on how to get in-depth atlases. To information from images by using a do this we computer. I now apply these techniques rely on image to neuroimaging data. registration (mapping) How and when did you join RIKEN? algorithms. I joined RIKEN about six years ago One of the

SUMMER 2021 5 BRIEFS

BRAIN SCIENCE

One of the aims of a new database of marmoset genes linked to developmental and psychiatric disorders is to identify the key brain regions involved.

Gene database RIKEN protects BDR Symposium A team led by Tomomi Shimogori and Henrik cherry blossoms The virtual RIKEN BDR Symposium 2021 Skibbe of the RIKEN Center for Brain Science Climate change may be why the cherry trees was held between March 1 and 3. The theme has created a database containing 2,000 in Kyoto reached full bloom on March 26 was Structuring Biosystems: Functions marmoset genes linked to expression patterns in 2021—the earliest date in 1,200 years of Emerging from Molecules. Twenty-five in developmental and psychiatric disorders records. The reason: the common Somei leading scientists talked about biomolecules and has identified risk genes for the disorders. Yoshino breed requires a protracted cold spell that sustain essential cellular functions to Comprehensive analysis revealed that genes before spring to flower profusely, a pattern 345 registrants from 22 different countries. involved in psychiatric and neurological that is becoming less common in southern Eisuke Nishida, BDR Center Director, disorders are expressed in specific brain Japan. In 2010, RIKEN’s Abe Tomoko and her noted that, while the cancellation of last regions and neuron clusters. Analysis of colleagues scrambled cherry-cutting DNA via year’s symposium due to the pandemic expression patterns in marmoset, mouse irradiation using a particle accelerator. The was regrettable, the new online format has and human brains showed many common result was the Nishina Otome variety, which allowed many who may not have been able to patterns between marmosets and humans. still flowers after a mild winter. Registrations join to participate. Next year’s symposium, The database will identify brain regions at the have also recently been granted for two new themed Emergence in Biological Systems: root of psychiatric disorders and the causes of varieties, Shinriko and Shinseiko, which Challenges to Bridging Hierarchies, will be genetic neural circuit dysfunction. bloom without low temperatures, and are held online in March 2022. https://doi.org/10.1073/pnas.2020125118 being sold from this year on. https://www2.bdr.riken.jp/sympo/2021/ © 2021 RIKEN

6 RIKEN RESEARCH BRIEFS

RNA diagnostic test for COVID-19 faster than current PCR detection

Scientists from the RIKEN Cluster for Pioneering Research have developed a new technology that can diagnose COVID-19 in minutes, by detecting single molecules of the SARS-CoV-2 virus’ RNA. Unlike when testing using PCR, the most common method, RIKEN’s method cuts out the time required for amplification of the RNA. The breakthrough, led by chief scientist Rikiya Watanabe and published in Communications Biology, was developed using a method called SATORI, which is a combination of leading- edge microchip technology and CRISPR- Cas13, which is used to detect nucleic acids. What is more, the cost per test is relatively close to that of the PCR test. In addition to detecting COVID-19, it is hoped SATORI technology could also be used to detect bio- markers of other diseases, including cancers. Read the paper: 10.1038/s42003-021-02001-8 At the new RIKEN Center for Quantum Computing, researchers are already creating the complex More: www.riken.jp/en/news_pubs/ architecture required of superconducting qubit computer processing. news/2020/20210419_2/index.html Japan’s new quantum center

Virtual open day The new RIKEN Center of Quantum Limited, with which On April 17, a virtual Open Day was Computing (RQC) was established on a joint research held for three RIKEN campuses in Wako, April 1, 2021. center was recently Tsukuba and Sendai. During the online It forms a focal point for a national established. event, Shun-ichi Amari, from the RIKEN strategy aimed at innovation in quantum RIKEN also Center for Brain Science, discussed the brain information technology. The center will serves as the and artificial intelligence, Atsushi Yoshiki focus on the basics of quantum infor- headquarters of of the RIKEN BioResource Research Center mation, as well as creating quantum the Quantum lectured on mouse models, and Tomoko computing systems and different types of Technology Abe from the RIKEN Nishina Center for qubits (see page 8). Innovation Hubs Accelerator-Based Science talked about The new center will focus on super- (QIH), which are Yasunobu Nakamura. creating novel plants using heavy-ion beams. conducting qubits, based on the work of also linked to the The Sendai campus offered a virtual director Yasunobu Nakamura and team government plan and have been set up lab tour and multimedia information on leader Jaw-Shen Tsai, as well as optical elsewhere, including at the Tokyo Institute terahertz-wave research. The Interna- quantum computers led by Deputy Director of Technology, the National Institute for tional Affairs Division also organized an Akira Furusawa, and hardware relating to Materials Science, the National Institutes informal virtual talk by Junichi Aikawa the use of various types of physical systems for Quantum and Radiological Science from the RIKEN Innovation project. including electron spins in semiconduc- and Technology, the National Institute Aikawa studies protein in termites. tors and atoms in vacuum. Software will of Information and Communications Another speaker at this virtual 'science also be explored with regards to quantum Technology, Osaka University, the National cafe', Alia Oktiavani, from the RIKEN computing theory, quantum algorithms Institute of Advanced Industrial Science and Center for Sustainable Resource Science, and quantum architecture. Technology, and the University of Tokyo. gave a talk titled ‘Unraveling how spiders Partners outside RIKEN include Fujitsu www.riken.jp/en/research/labs/rqc/

SUMMER 2021 7 INFOGRAPHIC

QUANTUM QUESTIONS The new RIKEN Center for Quantum Computing (RQC) is co-ordinating the Japanese-government's quantum agenda, and exploring a number of important approaches for qubits, quantum circuits and quantum architecture.

QUANTUM COMPUTING AND QUBIT 101 Researchers have long predicted that harnessing the complex quantum-mechanical properties of atoms and subatomic particles for computer processing could help tackle certain types of problems—especially those involving a daunting number of variables and potential outcomes, like simulations or optimization questions— faster than any classical computer.

Quantum computers can process A qubit is unique in that it can be in two Qubits can also be subject to information using 'qubits', which act in states simultaneously. For example, it entanglement, in which the state of one much the same way as classic binary can be placed into superpositions, in qubit is correlated to the state of one or bits. But while a bit represents either of which one state is imposed over another, more others, even if they are separated two distinct states (0 or 1), the unique as if the qubit then exists in both states by space. properties of a qubit means it can be in at once. more than two states (see right).

BITS (0 OR 1) QUBITS (SUPERPOSITION) QUBITS (ENTANGLEMENT)

The newly established RIKEN Center for Quantum Computing is exploring quantum frontiers. Four examples of their approaches are shown to the right.

8 RIKEN RESEARCH INFOGRAPHIC 123028 (2020) 22

New J. Phys. et al

SUPERCONDUCTING QUANTUM BIT OPTICAL QUANTUM COMPUTING CLUSTERS Superconducting circuits are macroscopic in size, but Developing useful qubit cluster states is key to scaling up 1 feature quantum properties such as quantized energy levels, 2 quantum computers, as they will help facilitate complex control superposition states and entanglement. Their qubits are manipulated by over many qubits. These clusters can be formed by entangled qubits—in using electromagnetic pulses that control the magnetic flux, the electric which the state of each qubit is correlated to the state of one or more other charge or the phase difference across a Josephson Junction (a device with qubits. Cluster states that use optical modes and multipartite entangled nonlinear inductance and no energy dissipation). On this RIKEN designed states could act as a sort of index for quantum information. The RQC wants 16-qubit superconducting circuit on a 1 cm2 silicon chip, the qubits are to use the uncertainty associated with the amplitude and phase of the state placed at the gray dots with rings. A number of holes in the chip electrically of light. If this quantum uncertainty is unequally distributed, the state is said connect the top and bottom surfaces. Coaxial wires for microwave signals to be squeezed; and the more the state is squeezed, the more photons are are attached to the backside of the chip to help with control and to read the correlated. Processing information via multi-photon squeezed light could states of the qubits. be a basis for optical quantum computing in cluster states.

SEMICONDUCTOR ELECTRON SPIN Spin is an intrinsic property of electrons, which can be 3 thought of as rotating around an axis in either a clockwise or ULTRACOLD ATOMS/ FLOATING ELECTRONS anticlockwise manner. Based on their spins, electrons react to magnetic Patterns of ultracold atoms or 2D formations created by electrons fields in different ways, for example, by aligning themselves with other 4 and using electrostatic charge to make them hover above liquid electrons in a specific pattern. In 2020, RIKEN researchers created a helium could provide the basis for new qubit systems. In 2020, RIKEN useful qubit system by controlling the synchronization of electron spins of researchers demonstrated single-atom resolved imaging of ultracold natural silicon quantum dots (found at the end of the red and gray lines, rubidium (87Rb) atoms in a triangular optical lattice. They managed a above) using microwave drive. The group showed that a resonant drive detection fidelity of 96.3% during imaging through machine-learning-based controlled the electron spins of two silicon quantum dots that aligned with automatic optimization of the Raman sideband experimental parameters for an accuracy of 99.6%, the highest reported for two-spin synchronization. fluorescence imaging. © 2021 RIKEN; Arjan van Loo; Optical Quantum Computing Research Team, RQC ; Reprinted, with permission, from Ref. 1. Copyright (2020) by the American Physical Society; Ryuta Yamamoto

SUMMER 2021 9 RESEARCH HIGHLIGHTS

SKYRMIONS Revealing the origins of skyrmion lattices Interactions between electrons help to organize magnetic whirlpool structures into a repeating grid

IKEN physicists have the ruthenium atoms contribute R discovered how interactions ‘itinerant’ electrons that are between electrons can stabilize more mobile. a repeating arrangement of The team had previously found swirling magnetic patterns that by applying a magnetic field known as skyrmions, which to the material, they could create could help to further exploit a square lattice of skyrmions these structures1. arranged in a grid pattern at The spin of an electron causes intervals of about 2 nanometers. it to behave like a miniature In the new study, they used a magnet. In a skyrmion, many technique called spectroscopic- of these spins are arranged in a imaging scanning tunneling swirling pattern that resembles microscopy (SI-STM) to study the a tiny tornado. Skyrmions are itinerant electrons in GdRu2Si2. highly promising as a means of The researchers cooled carrying information in a new the material to −271 degrees generation of high-density, low- Celsius and applied a range energy data-storage devices. of magnetic fields to generate Skyrmions behave as if they different magnetic patterns. are distinct particles, and SI-STM measurements showed multiple skyrmions can arrange that changes in the material’s themselves into a regular grid magnetic patterns were reflected within certain types of material. in the distribution of itinerant But researchers are still debating electrons. Crucially, the team how these stable skyrmion also saw that the skyrmion lattices form. lattice pattern is imprinted on the material’s itinerant electrons, due to interactions between the This could provide spins of localized and itinerant researchers with a electrons. The researchers suggest that useful tool to study The crystal structure of gadolinium ruthenium silicide, which can host a square these interactions could play an lattice of swirling magnetic skyrmions (orange = gadolinium; green = ruthenium; skyrmion lattices in important role in the formation blue = silicon). of the square skyrmion lattice. other materials “The proposed mechanism by SI-STM, lending support to Reference stabilizes skyrmion lattices,” the mechanism proposed by the 1. Yasui, Y., Butler, C. J., To discover more about says Yasui. researchers. Khanh, N. D., Hayami, S., skyrmion lattices, Yuuki Yasui at The team also performed In addition to providing clues Nomoto, T., Hanaguri, the RIKEN Center for Emergent theoretical calculations, based about how skyrmion lattices are T., Motome, Y., Arita, R., Arima, T., Tokura, Y. & Seki, Matter Science and colleagues on the interactions between stabilized, the research shows S. Imaging the coupling studied a metallic material called localized and itinerant electrons, that SI-STM can be used to between itinerant electrons gadolinium ruthenium silicide to predict the distribution of indirectly monitor the behavior and localised moments in the centrosymmetric (GdRu2Si2; see image). Electrons itinerant electrons in the material of skyrmions. “This could skyrmion magnet GdRu2Si2. in the material’s gadolinium under different magnetic fields. provide researchers with a useful Nature Communications 11, atoms are largely responsible for These distributions were very tool to study skyrmion lattices in 5925 (2020). its magnetic properties, while similar to the patterns observed other materials,” says Yasui. Modified from Ref. 1 and licensed under CC BY 4.0 Yasui © 2021 et Y. al

10 RIKEN RESEARCH RESEARCH HIGHLIGHTS

COVID-19 Glycans play crucial role in COVID-19 infection Simulations by a pair of supercomputers reveal how glycans help SARS-CoV-2 to invade cells

fforts to design drugs for spike proteins, the detailed R-CCS and Oakforest-PACS the spike protein that play an E preventing and treating molecular structure of the at the University of Tokyo. important role in stabilizing COVID-19 stand to benefit highly fluctuating glycans is Using these powerful machines, the structure of the receptor- from the discovery by RIKEN still not understood and the role they performed molecular binding domain. Their results scientists that sugar molecules glycans play in the process of cell dynamics simulations of the suggest that electrostatic called glycans play an important invasion remains unclear. spike proteins at a time scale of repulsion between the domains role in the structural changes 1 microsecond. drives the conformational that occur when SARS-CoV-2, “Research projects like this change to the up-form the virus that causes the disease, “We need to develop show us how the new generation structure. They also indicate invades a human cell1. of powerful supercomputers that glycans that stabilize When invasion occurs, a spike better preventative will allow us to gain new the down-form structure are protein on the virus’ surface and therapeutic insights into many phenomena dislodged and replaced by other binds to an enzyme called ACE2 measures to bring by performing simulations at a glycans after the domains are on the surface of the cell. The level of detail that would have displaced. spike protein consists of three the pandemic to been impossible previously,” Information like this is polypeptide chains, and it has an end” says Sugita. valuable for combating the glycans attached to its surface. The study provided new pandemic. “We need to These glycans are thought to insights into how glycans develop better preventative help viruses to evade attack Now, a team led by Yuji Sugita help to stabilize the dynamic and therapeutic measures to by antibodies produced by the of the RIKEN Center for structure of the proteins. From bring the pandemic to an end,” body’s immune system. Computational Science (R-CCS) the calculations, the team says Sugita. “It would be very Structural analyses have has conducted molecular was able to identify specific useful to be able to design drugs shown that the spike proteins dynamics simulations for the glycan-attached amino acids in taking the structural changes of SARS-CoV-2 have up- and up- and down-form structures of spike proteins into account, down-form structures. While of the proteins, using two by stabilizing the down-form these analyses have advanced supercomputers—Fugaku at the or inhibiting the change to the our understanding of the three- up-form, for example.” dimensional structure of the

Reference 1. Mori, T., Jung, J., Kobayashi, C., Dokainish, H. M., Re, S. & Sugita, Y. Elucidation of interactions regulating conformational Illustration of spike proteins on the SARS-CoV-2, the coronavirus that stability and dynamics of causes COVID-19. Molecular dynamics SARS-CoV-2 S-protein. simulations by RIKEN researchers have Biophysical Journal 120, shown that the glycans help stabilize 1060–1071 (2021).

ROOT GRAVITROPISM Choreographing the downward dance of plant roots The identification of a transporter protein involved in root gravitropism should benefit agriculture

n a finding that could be responses and root gravitropism I used to improve the nutrient in the model plant Arabidopsis. uptake of crops, a RIKEN-led “We noticed that seedlings in team has identified a trans- which the gene encoding NPF7.3 porter protein that is involved was mutated displayed abnormal in the tendency of plant roots to root growth,” says Mitsunori grow downwards in response to Seo of the RIKEN Center for gravity, a phenomenon known as Sustainable Resource Science. root gravitropism1. “Closer inspection revealed Charles Darwin was among specific defects in gravitropic the first scientists to investigate responses, which were not root gravitropism in plants. explained by previously reported Through simple but elegant functions of NPF7.3 as a nitrate experiments, Darwin showed and potassium transporter. This that plant root tips sense gravity made us suspect that this protein and that they transmit the might have additional, previously signal to neighboring tissues so uncharacterized functions.” that roots bend toward gravity. Subsequent experiments We now know that the plant demonstrated that NPF7.3 hormone auxin plays a key role functions as a transporter of in this gravitropic response. indole-3-butyric acid (IBA), and that IBA taken up by specific root cells via NPF7.3 is converted This should improve into indole-3-acetic acid (IAA), which is the major naturally the uptake of water occurring plant auxin. This helps establish auxin gradients in root and nutrients by roots Asymmetric distribution of auxin activities (shown in red), which is required for tissues, which in turn direct the proper gravitropic responses, is observed in wild type (top), but not in roots in gravitropic response. which the gene encoding NPF7.3 is mutated (bottom). Plant hormones serve many IBA is a minor precursor of physiological functions and help IAA, and the involvement of IBA- NPF proteins were originally plants withstand fluctuations in derived IAA in gravitropism was identified as nitrate or peptide Reference their environment. To function previously unknown. However, transporters, but it is becoming 1. Watanabe, S., Takahashi, N., Kanno, Y., Suzuki, properly, their distribution and it seems likely that other plants, clear that they are more H., Aoi, Y., Takeda- activity in cells and tissues must including crop species, share adaptable than previously Kamiya, N., Toyooka, K., be precisely choreographed. similar regulatory mechanisms, thought. “Recent studies, Kasahara, H., Hayashi, This often involves transporter which could lead to agricultural including this one, indicate that K. et al. The Arabidopsis proteins that mediate the uptake and horticultural applications. this transporter family conveys NRT1/PTR family protein NPF7.3/NRT1.5 is an or export of hormones or their “We will be able to modify various compounds including indole-3-butyric acid precursors by cells. root architecture by regulating plant hormones and secondary transporter involved in root RIKEN biologists have IBA transport,” says Seo. “This metabolites,” says Seo. “As a next gravitropism. Proceedings now shown that a previously should improve the uptake of big question, we want to know of the National Academy of Sciences USA 117, 31500– described transporter protein, water and nutrients by roots, and how NPF proteins recognize 31509 (2020).

NPF7.3, regulates auxin hence promote crop production.” such a variety of substrates.” Science Sustainable Resource for RIKEN Center 2021 ©

12 RIKEN RESEARCH RESEARCH HIGHLIGHTS

THE CRAB PULSAR Giant pulses have gigantic levels of energy After decades of observations, astronomers have finally found clear evidence of an increase in x-ray emission associated with giant pulses previously observed in the radio band

he giant pulses emanating T from the Crab pulsar may be hundreds of times more energetic than previously believed, observations by RIKEN astronomers suggest1. They found an increase in x-ray emission associated with the giant radio pulses. A dozen pulsars in our Galaxy emit extremely short (microsecond duration) pulses of radio waves known as giant radio pulses. Little is known about the mechanism that causes them. They may be the origin of the mysterious phenomenon known as fast radio bursts—rapid bursts of radio waves that are believed to originate from energetic events in the extragalactic universe. To gain insights into these phenomena, the RIKEN-led group made coordinated observations of the Crab pulsar—one of the most famous and well- observed pulsars. Chinese and Giant pulses from the Crab pulsar in the Crab Nebula (shown) may be hundreds of times more energetic than previously thought. Japanese observers witnessed the explosion of this star in a instrument aboard the Interna- previously thought,” says fast radio burst science but also supernova explosion in 1054, tional Space Station, while the Teruaki Enoto, the leader of the represents a fitting legacy for and it led to the formation of the radio observations were made by Extreme Natural Phenomena the Kashima 34-meter telescope, beautiful Crab Nebula that can two observatories in Japan. After RIKEN Hakubi Research Team. which was a valuable instrument still be seen today. continuing the campaign for These observations also for the radio-astronomy The group began looking three years, the team eventually impose important constraints community but was irreparably to see if there was an increase found a clear signal indicating an on models of fast radio bursts, damaged by a typhoon in 2019,” in x-ray emissions associated enhancement of x-ray emissions which are thought to be associ- adds Enoto. with giant radio pulses. Despite associated with an increase at the ated with pulsars and possibly many observations over several radio wavelength. young ones like the Crab pulsar. decades, researchers had been The enhanced emission “However, the relationship Reference unable to make any unam- detected in the x-ray band between the two is still con- 1. Enoto, T., Terasawa, T., Kisaka, S., Hu, C.-P., Guillot, biguous detections in x-rays. was similar to that previously troversial,” says Enoto. “These S., Lewandowska, N., The observations were based reported in the visible band, findings, along with upcoming Malacaria, C., Ray, P. S., on a coordinated international but nothing similar has ever discoveries regarding fast radio Ho, W. C. G., Harding, A. campaign of simultaneous been observed from any of the bursts, will help us to understand K. et al. Enhanced x-ray space-based x-ray and ground- other 2,800 known pulsars. the relationship between these emission coinciding with giant radio pulses from the based radio observations. “Our measurements imply that phenomena.” Crab Pulsar. Science 372, The space-based observations these giant pulses are hundreds “Our result not only has a 187–190 (2021).

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The theoretical prediction of Majorana fermions in superconducting topological crystalline insulators could lead to them being used in quantum computers.

TOPOLOGICAL SUPERCONDUCTORS that the crystalline symmetry that creates the surface states in a topological crystalline insulator New way to create particles for also plays an important role in protecting Majorana fermions. quantum computers predicted Furthermore, the pair discovered that these systems can A large class of quantum materials could host hypothetical particles support states with multiple useful for quantum computers Majorana fermions. Unlike a single Majorana fermion, these multiple Majorana fermions broad class of quantum been created in exotic materials. still highly challenging to create can react to external perturba- A materials could be used Quasiparticle Majorana Majorana fermions.” tions such as magnetic fields to create particles for use in fermions have been observed Kobayashi and his CEMS or physical strain. This finding quantum computers, calcula- at the interface between super- colleague Akira Furusaki are offers ways to manipulate the tions by two RIKEN theoretical conductors and topological hoping to make it easier to form fermions, which is vital if they physicists have predicted1. insulators—materials that are Majorana fermions through are to be implemented in a topo- Every fundamental particle has electrically insulating on the identifying a broader range of logical quantum computer. an antiparticle counterpart with inside but conduct a current materials that can support them. “The next step will be to apply the same mass but the opposite on their surfaces. Majorana So they theoretically investigated our generalized mechanism to electric and magnetic character- fermions observed in this two- a type of topological insulator material databases and predict istics. For example, the antipar- component system maintain known as a topological crys- materials that are suitable ticle of the negatively charged their state even in the presence talline insulator, in which the for achieving these Majorana electron is the positively charged of defects and disturbances. surface is conducting due to fermions,” says Kobayashi. positron. This robustness makes them the symmetry of the material’s A special class of particles promising as a platform for atomic structure. that are their own antiparticles quantum computation. “Recent work that combined Reference has been theoretically predi- “Recent experiments have calculations and material 1. Kobayashi, S. & Furusaki, A. Double Majorana cated. These so-called Majorana found evidence for a Majorana databases has theoretically vortex zero modes fermions have not yet been fermion at vortices in hybrid uncovered several thousand in superconducting identified in experiments that systems of topological insulators topological materials with topo- topological crystalline probe the physics of elementary and superconductors,” explains logical phases enabled by crystal- insulators with surface rotation anomaly. Physical particles. However, composite Shingo Kobayashi from the line symmetry,” notes Kobayashi. Review B 102, 180505 particles or quasiparticles that RIKEN Center for Emergent The calculations performed by (2020). mimic the same properties have Matter Science (CEMS). “But it is Kobayashi and Furusaki showed LIBRARY/Getty SAKKMESTERKE/SCIENCE© PHOTO

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INDUCTORS Bringing inductors down to size Inductors are set to join other electronic components in being miniaturized thanks to a quantum effect

obile-phone chargers M and other devices could become much smaller after an all-RIKEN team of physicists successfully shrunk an electrical component known as an inductor to microscale dimensions using a quantum effect1. Inductors are a basic component of modern electrical circuits, and they are used in a wide range of applications including information processing, wireless circuits and chargers for mobile devices. They are based on the law of induction that English physicist Michael Faraday discovered in 1831. But while physics has made great leaps since then, the fundamental principles of inductors remain essentially the same—they are basically coils of wire. Unlike other electrical circuit components, inductors have A conventional inductor mounted on a printed circuit board. Inductors have resisted miniaturization until now, but the been difficult to miniaturize demonstration of a quantum source of inductance by RIKEN researchers promises to result in much smaller inductors. because the size of their inductance diminishes with their increases with decreasing specially engineered systems. The team’s nanoscale inductor volume, such that if you halve cross-sectional area. In the present study, the team operates only at very low their volume, the inductance “We discovered an realized this effect by using a temperatures, so they are now drops by half too. electromagnetic inductance of micrometer-scale magnet. The looking for materials that behave Now, Yoshinori Tokura, quantum-mechanical origin,” electron spins that give rise to similarly at high temperatures. Tomoyuki Yokouchi and their says Yokouchi. “This has big the magnetism are arranged “For applications, we have to find co-workers, all at the RIKEN potential for the miniaturization in a spiral-like arrangement, a material that generates emergent Center for Emergent Matter of inductors, one of the mimicking the coils of a inductance at and above room Science, have generated an most fundamental parts of conventional inductor. temperature,” says Yokouchi. inductance equivalent to that contemporary electric circuits.” Yokouchi notes that the “We’ve already started searching of commercial inductors but in One of the authors, Naoto success of the study hinged on for prospective materials.” a component whose volume is Nagaosa, had previously the collaborative environment about a million times smaller. theoretically proposed a at RIKEN. “Strong collaboration They achieved this by using a totally new mechanism for between theorists and Reference 1. Yokouchi, T., Kagawa, F., new mechanism for generating electromagnetic induction based experimentalists was essential Hirschberger, M., Otani, Y., inductance that depends on on emergent electromagnetism, for this project,” he says. In Nagaosa, N. & Tokura, Y. quantum effects. Inductors a new form of electromagnetism particular, the experimentalists Emergent electromagnetic based on this mechanism that arises from the quantum- have tremendous expertise induction in a helical-spin magnet. Nature 586, will be easy to shrink since mechanical properties of in fabricating advanced 232–236 (2020).

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MUTATION BREEDING Supersized snacks for growing fish Larger strains of zooplankton could improve survival rates in fish farms

RIKEN-led team has “We decided to try to do A developed larger strains something to improve the of zooplankton, which are an survival rate of fish larvae, as important feed stock in fish this would help to increase nurseries, by creating mutations aquaculture productivity,” with a heavy-ion beam1. These says Tomoko Abe of the RIKEN new strains could improve Nishina Center for Accelerator- the survival rate and optimize Based Science. “We thought that the growth of juvenile fish if we could create a large rotifer in farms. strain using our expertise, it Food shortages due to would contribute to stabilizing population growth and the income for aquafarmers.” increased consumption are The team used a technique a major global concern, and known as heavy-ion-beam countries around the world irradiation to create larger are seeking ways to increase rotifers. It involves exposing food production. Resources cells to a beam of heavy atomic from the oceans, which cover nuclei. By adjusting the type 70% of the Earth’s surface, are of ion and dose, the beam can one promising solution to this induce random mutations in challenge. the genome, and strains with desirable phenotypes can be selected. The bred rotifers Using the RIKEN RI Beam were approximately Factory, the team irradiated proliferating rotifers with 1.2 times larger beams of argon and carbon than other strains ions. They then selected larger individuals and cultured the plankton for several Economically important generations to create a large A differential interference contrast light micrograph of a rotifer. RIKEN researchers fish species, such as bluefin mutant line. The bred rotifers have created larger strains of the zooplankton, which is used for feeding fish in tuna, yellowtail and flatfish, were approximately 1.2 times fish farms. are fed live bait until they are larger than other strains, sufficiently large to be fed which the team judged would large mutant among live rotifers with artificial foods. Rotifers be an ideal size for growing that are moving quickly around Reference (see image) are a type of juvenile fish. under a microscope was far more 1. Tsuneizumi, K., Yamada, animal plankton, and they are Some of the strains were difficult than we had anticipated M., Kim, H.-J., Ichida, H., Ichinose, K., Sakakura, Y., commonly used as the initial not only larger, but also grew and actually was the hardest part Suga, K., Hagiwara, A., live food. Fish need progressively faster than the parent strains. of this study.” Kawata, M., Katayama, larger bait as they grow, but “In general, larger mutants The enlarged rotifers could T. et al. Application of rotifers are often too small to grow more slowly than normal provide a stable supply of larger heavy-ion-beam irradiation to breeding large rotifer. satisfy the growing fish, leading rotifers, but we were lucky to rotifers at low cost, enhancing Bioscience, Biotechnology, to cannibalism or growth discover a line that grows not aquaculture. The team now plans and Biochemistry 85, abnormalities that curb the only larger but faster as well,” to see if the larger rotifers survive 703–713 (2021). survival rate. says Abe. “However, picking a longer in field tests. © WIM VAN EGMOND / SCIENCE PHOTO LIBRARY

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Chemists at RIKEN have found that the photoionization of phenol occurs 10,000 times faster at the interface between water and air than entirely within water.

INTERFACE CHEMISTRY Chemical reaction zips along at water surface A light-induced reaction proceeds much faster at the surface of water

chemical reaction powered light to analyze the photoioni- also very important for catalytic A by light occurs about 10,000 The same reaction zation of phenol, a reaction chemistry, the field of study that times faster at the interface in which light knocks out an aims to promote and control between air and water than also occurred at an electron and a proton from a chemical reactions,” says Tahara, within water, three RIKEN air–water interface, phenol molecule. They found that who led the trio. chemists have demonstrated1. the same reaction also occurred The findings could have impli- This finding could improve but roughly 10,000 at an air–water interface, but cations for environmental studies our understanding of the many times faster roughly 10,000 times faster due to as well. “Water in nature exists important chemical and biologi- the different conditions there. as seawater, which has bubbles cal processes that occur at the “It was exciting to find that and aerosols, thus having a vast water surface. who were all at the RIKEN the reaction speed for phenol surface area. Our work could help Chemical reactions that occur Molecular Spectroscopy is so phenomenally different,” us to understand how molecules at the interface between air and Laboratory at the time of the says Nihonyanagi. “But in are adsorbed and react on the water abound in nature and study, have used an advanced addition, our method for directly surface of water, leading to the many industrially important spectroscopy technique to observing chemical reactions elucidation of chemical reactions processes. Considerable indirect take high-speed movies of at the water surface in real time that have an enormous impact on evidence indicates that chemical the intermediate molecules could also be applied to other the global environment.” reactions at water interfaces created as a chemical reaction reactions, and might help us get differ from those in water. But occurred at an interface. The a better understanding of how reactions at liquid interfaces are movie frames were obtained reactions proceed in this special Reference 1. Kusaka, R., Nihonyanagi, difficult to study because it is so every 100 femtoseconds or environment.” S. & Tahara, T. The hard to isolate the molecules on so (1,000 femtoseconds are “The fact that there is a 10,000- photochemical reaction of the surface from those immedi- equivalent to one trillionth of fold difference in the reaction phenol becomes ultrafast ately below the surface. a second). rate of a basic organic molecule at the air–water interface. Nature Chemistry 13, Now, Ryoji Kusaka, Satoshi The researchers’ method used such as phenol between the bulk 306–311 (2021).

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RIKEN researchers have found that the gene that codes for a key regulator of the formation of synapses between neurons in the brain such as these is mutated in people with schizophrenia.

SCHIZOPHRENIA in various mouse models of schizophrenia. However, because fenofibrate A new drug target for schizophrenia does not readily cross the blood– brain barrier, the scientists had A protein involved in fat metabolism is also found to control synaptic growth, to administer very high doses a process that’s deficient in schizophrenia-affected brains of the drug. That approach would be risky in people, says Maekawa, since fenofibrate can ew therapies that improve Yoshikawa and Motoko Additionally, mice engineered to sometimes seriously damage N connectivity and circuitry Maekawa from the RIKEN lack PPARα displayed behavioral muscle tissue. To avoid that in the brains of people with Center for Brain Science and molecular deficits consistent potential side effect, drug schizophrenia could result from focused on a metabolic pathway with symptoms of schizophrenia. developers may have to refine the discovery by a RIKEN-led previously implicated in the A gene-expression analysis the chemistry of fenofibrate or team of a potential new target development of schizophrenia. of brain tissue taken from discover new agents that activate for drugs to treat the psychiatric They used targeted sequencing the mutant and normal mice PPARα. “To test the therapeu- disorder1. techniques to probe six genes, revealed that PPARα is a key tic strategy in people, we need Treatment for schizophrenia each encoding a protein from regulator of synapse formation more drugs that penetrate has not changed much in 60 the peroxisome-proliferator- in the brain. This adds to the the brain for clinical trials,” years. Doctors still generally activated receptor (PPAR) family protein’s known metabolic role Maekawa says. prescribe medicines designed or one of its signaling partners. throughout the body. to tame psychosis by blocking By conducting a genetic To boost synaptic function—a neurotransmitter signaling in analysis of 1,200 people with well-documented problem in Reference 1. Wada, Y., Maekawa, the brain. While the drugs ease schizophrenia, the research- people with schizophrenia—the M., Ohnishi, T., Balan, symptoms such as delusions ers identified several harmful team gave mice a drug called S., Matsuoka, S., and hallucinations, they leave mutations in the gene encoding fenofibrate, which activates Iwamoto, K., Iwayama, many other aspects of the illness PPARα that were absent in a PPARα. Fenofibrate is already Y., Ohba, H., Watanabe, A., Hisano, Y. et al. untreated and their side effects large sequence database of DNA taken by millions of people every Peroxisome proliferator- can be off-putting to many from Japanese individuals in day to help control cholesterol activated receptor α patients. Researchers are thus the general population. Experi- and fat levels in the blood. The as a novel therapeutic keen to find new targets for drugs. ments involving cells showed researchers showed that the target for schizophrenia. In search of new molecular that these mutations reduced drug helped alleviate brain EBioMedicine 62, 103130 (2020). targets, a team led by Takeo the expression levels of PPARα. and behavioral abnormalities Viaframe/Getty©

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ASTROPHYSICS Mysterious magnetar may power bright binary star The enormous magnetic field generated by a spinning neutron star could explain the intense luminosity of a binary star system

strophysicists are better A positioned to understand mysterious magnetars—neutron stars that boast the strongest magnetic fields in the Universe— after RIKEN researchers found evidence that the brightest gamma-ray binary star system in our Galaxy may contain a magnetar1. Known rather prosaically as LS 5039, the binary system consists of two stars that accelerate particles to extremely high energies, generating powerful gamma rays. One star is a hot, blue-white star about 23 times more massive than our Sun. The other was thought to be a pulsar, a spinning neutron star that emits beams of electromagnetic radiation as it rotates, rather like the beams of a lighthouse.

“Our result Observations of high-energy x-rays from the binary-star system LS 5039 suggest that it harbors a powerful magnetar (blue challenges the and white sphere on bottom left). current most popular scenario for Based on observations from two “We were surprised by this, to do next is to confirm the space telescopes, they found that because our result challenges the pulsation by an additional hard this binary system” LS 5039 emits high-energy x-ray current most popular scenario x-ray observation,” says Yoneda. pulses every 9 seconds. Their for this binary system,” says Further observations may also Previous observations of observations suggest that the Yoneda. “So far, all magnetars pin down a more precise mass LS 5039 had not revealed any pulsar has a mass of 1.23–2.35 have been found as isolated for the magnetar, which could pulses from the pulsar, which may times that of our Sun. systems. If our findings are help to reveal why they differ have been due to disruption of the But the researchers’ analysis true, the magnetar in LS 5039 from normal neutron stars that telltale beams by a stellar wind—a showed that an ordinary pulsar is the first one to be found in a have weaker magnetic fields. stream of gas and particles could not supply enough energy binary system.” pouring from the larger star. to generate LS 5039’s powerful The researchers suggest that Now, Hiroki Yoneda of the gamma rays. Instead, they LS 5039 is so bright because Reference 1. Yoneda, H., Makishima, K., RIKEN Nishina Center for found that the star is most the magnetar is immersed in Enoto, T., Khangulyan, D., Accelerator-Based Science and likely to be a rotating magnetar, its companion’s stellar wind, Matsumoto, T. & Takahashi, his colleagues have studied x-rays with a magnetic field roughly leading to interactions that T. Sign of hard-X-ray emitted by LS 5039 that are more 1,000 times stronger than accelerate electrons in a few pulsation from the γ-ray energetic than those investigated typical pulsars—and about one seconds to extreme levels (of the binary system LS 5039. 15 Physical Review Letters in previous studies and are thus quadrillion (10 ) times stronger order of teraelectronvolts). 125, 111103 (2020).

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EPIGENETICS Unfertilized egg modifications key to some traits Two epigenetic marks in an unfertilized mouse egg cell determine inherited DNA modifications

n a discovery that has The team discovered a mark where subsequent H3K27me3 I implications for reproductive left behind in unfertilized egg should follow. medicine, RIKEN scientists have cells that determines which “We discovered that found that miscarriages and DNA modifications would be H2AK119ub1 is necessary enlarged placentas can occur if inherited if the egg is fertilized. for maternal inheritance a mouse egg cell with normal Specifically, they found that of H3K27me3, making the DNA lacks proper epigenetic without initial modifications H2AK119ub1-H3K27me3 instructions1. to histone H2A at lysine 119 pathway a major player in For many years, students (H2AK119ub1), later inheritable transgenerational epigenetic were taught that acquired modifications would not occur. inheritance in mammals,” traits are not inherited. In One consequence of this deficit says Inoue. some sense, this is correct; was an enlarged placenta after Surprisingly, testing showed stretching your neck embryo implantation. that the loss of H3K27me3 was a lot will not result in itself inherited by fertilized children with longer embryos, and could not be necks. However, your It was surprising reversed. Furthermore, this DNA function can be to find that defects deficiency led to increased modified throughout miscarriages and enlarged your life. For example, in an egg’s histone placentas. “It was surprising DNA in chromosomes modification to find that defects in an is supported by egg’s histone modification proteins called histones, are irreversibly are irreversibly inherited by which can be modified, inherited by embryos and cause long-term changing how genes consequences in development,” are expressed in the embryos says Inoue. body. These changes These findings have clinical are known as epigenetic The researchers first examined implications, especially for modifications. the timing of the two histone reproductive medicine and Previously, Azusa Inoue modifications. They found that placental defects. “The next step at the RIKEN Center every gene exhibiting H3K27me3 is to see whether any diseases for Integrative Medical also showed H2AK119ub1 in or surrounding environments Sciences and his mouse egg cells. can affect the heritable histone colleagues had found Suspecting its importance, modification,” says Inoue. that acquired the researchers knocked out trimethylation two proteins that make up of histone H3 H2AK119ub1 in egg cells. They Reference at lysine 27 found that the knock-out egg 1. Mei, H., Kozuka, C., Hayashi, R., Kumon, (H3K27me3) cells had much less H3K27me3 M., Koseki, H. & Inoue, in mammalian than controls at a subset of A. H2AK119ub1 guides egg cells can be genes that normally bring maternal inheritance inherited. Now, H3K27me3 into the next and zygotic deposition of H3K27me3 in mouse in a new study, generation. Thus, H2AK119ub1 embryos. Nature Genetics they investigated acts like a kind of marker 53, 539–550 (2021). how this happens. left by a scout, identifying

Light micrograph of a 13 day old mouse embryo. RIKEN researchers have found that histone modifications to an

unfertilized mouse egg cell are irreversibly inherited by embryos, leading to long-term consequences in development. © CRAIG RHODES AND KENNETH YAMADA LCDB / / NIDCR / NATIONAL INSTITUTES OF HEALTH SCIENCE / PHOTO LIBRARY

RIKEN RESEARCH RESEARCH HIGHLIGHTS

Illustration of the central region of a protoplanetary disk. RIKEN astronomers have found that these infant planetary systems exhibit a surprising variation in the organic compounds they contain.

ASTROCHEMISTRY there is little comparative data hinting that there is something to understand these young stars about the denser conditions that Organic make-up of as a group. The RIKEN-led allows them to be abundant. group decided to use observa- “This raises important tions from the ALMA obser- questions regarding how special planetary systems vatory in Chile, whose high the chemical environment of resolution allows scientists to the infant Solar System is,” says differs from early on study chemical compounds in Nami Sakai, leader of the RIKEN protoplanetary disks. Star and Planet Formation Labo- Infant planetary systems show a surprising The group surveyed the ratory. “We will be able to answer variation in the organic compounds they contain emission from organic molecules this question in the future at specific frequencies in very by examining the chemical young disks. They looked at evolution of the gas surrounding n a finding that has implica- used to explain why we have not methanol and acetonitrile, as well young protostars. We hope that I tions for the origins of life on found evidence of life outside as two larger molecules: methyl such knowledge will be a base for Earth, a RIKEN-led interna- the Earth. However, the last two formate and dimethyl ether. The understanding the origin of life tional team has discovered that decades have revealed that these researchers found that different on the Earth.” 50 regions where protoplanetary molecules are actually common. regions exhibited large variations disks are forming in the Perseus “Today, scientists have begun in the abundances of methanol molecular cloud contain quite to systematically survey proto- and acetonitrile. Intriguingly, Reference differing amounts of complex planetary disks—disks where the relative abundance between 1. Yang, Y.-L., Sakai, N., organic molecules1. Interest- planets eventually form around the two species was remark- Zhang, Y., Murillo, N. M., ingly, the chemically rich young a star—in the hope of determin- ably similar. “This implies that Zhang, Z. E., Higuchi, A. E., Zeng, S., López- disks have similar compositions ing how these molecules form, there is a common produc- Sepulcre, A., Yamamoto, of organic molecules. These how common they are, and what tion mechanism of these two S. & Lefloch, B. The findings raise an important impact they have on planetary molecular species, and this gives Perseus ALMA Chemistry question: do solar-like systems systems,” says Yao-Lun Yang, us important hints on how they Survey (PEACHES). I. The complex organic share a common chemistry who was at the RIKEN Star and form in space,” says Yang. molecules in Perseus at birth? Planet Formation Laboratory at In addition, the abundances embedded protostars. The Complex organic molecules the time of the study. of methyl formate and dimethyl Astrophysical Journal 910, were once thought to be rare in Although astronomers have ether tended to be higher relative 20 (2021).

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NUCLEAR PHYSICS Alpha particles lurk at the surface of neutron-rich nuclei Measurements on neutron-rich tin nuclei uncover alpha particles in their outer layer

ew insights into the series of neutron-rich isotopes of N structure of neutron stars tin ranging from tin-112, which and the radioactive process of has only 62 neutrons, to tin-124, alpha decay could result from which has 74 neutrons and hence a RIKEN-led study, finding a much thicker neutron skin. evidence that alpha particles— They knocked out alpha particles groups of two protons and two from the nuclei by bombarding neutrons—may lie at the surface them with protons and then of heavy atomic nuclei that are examined how frequently they rich in neutrons1. were able to observe alpha Neutron stars are extremely particles in progressively dense, being composed almost heavier isotopes. entirely of neutrons. Matter The team identified alpha exists at similar densities, albeit clusters in the very surface at a much smaller scale, in region of neutron-rich tin atomic nuclei. atomic nuclei, implying that the so-called neutron skin does not consist only of neutrons, This finding but also contains alpha clusters. has important Importantly, they discovered that the probability of finding implications for alpha clusters in nuclei decreased our understanding gradually with the number of neutrons. The researchers of the nuclear attributed this decrease to the equation of state interplay between alpha-cluster and neutron stars formation and the thickness of the neutron skin that surrounds the nucleus. Nuclear physicists at RIKEN have discovered that the neutron skin at the surface “Intriguingly, despite the vast This finding has of neutron-rich tin nuclei contain alpha particles. difference in size and mass, important implications for the tiny atomic nuclei found our understanding of the an alpha particle. About shed light on the origin of alpha on Earth and the enigmatic nuclear equation of state and 90 years ago, physicist George particles in alpha decay. neutron star are actually neutron stars. In the near Gamow proposed that alpha governed by the same type of future, electromagnetic and decay occurs due to quantum interactions,” notes Zaihong gravitational-wave observations tunneling of preformed alpha Reference Yang of the RIKEN Nishina will provide more-accurate particles or clusters. However, 1. Tanaka, J., Yang, Z., Typel, Center for Accelerator-Based data on the properties of although the theory was S., Adachi, S., Bai, S., van Science. This connection neutron stars. generally accepted, it has never Beek, P., Beaumel, D., Fujikawa, Y., Han, J., Heil, is expressed by the nuclear The study is also a key step been conclusively shown that S. et al. Formation of α equation of state, which relates toward a full understanding such clusters exist in heavy clusters in dilute neutron- the pressure and the density of of alpha decay—radioactive atoms. Hence, the finding rich matter. Science 371, nuclear matter. decay in which an atomic that alpha clusters exist at the 260–264 (2021).

The researchers investigated a nucleus spontaneously emits surface of heavy nuclei could © PROF. K.SEDDON & DR. T.EVANS, QUEEN'S UNIVERSITY BELFAST / SCIENCE PHOTO LIBRARY

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The formation of haustoria in Phtheirospermum japonicum seedlings grown on agar under different conditions.

PLANT DEVELOPMENT Parasitic plants make their point with ethylene The hormone ethylene plays a critical role in the infectious activity of parasitic plants

he invasive organs of looked for plants that developed seems to be very sensitive to ethylene is perceived by parasitic plants such as abnormal haustoria. They ethylene signaling, but since the parasite. 1492–1503 (2016); permission conveyed through Copyright Clearance Center, Inc. Center, Copyright Clearance through conveyed permission (2016); 1492–1503 T witchweeds and broomrapes found two mutants in which the mutations did not affect the Taken together, these findings 170,

respond to the hormone ethylene the haustoria grew longer than number of haustoria, ethylene indicate that ethylene signaling when invading the roots of usual and also began to produce signaling is not needed early in guides the various stages of their hosts, RIKEN researchers transport tissues even in the haustorium development. haustorium development. Cui have found1. This finding could absence of a host root. Turning to the later stages of believes that uncovering the Plant Physiology Plant . provide researchers with new The team then used whole- haustorium growth, the team basic biology of the parasite will et al avenues for controlling these genome sequencing to identify found that cell proliferation lead to strategic ways to tackle destructive plants. the mutations. Surprisingly, continued for longer in the it. “I’m continuing this work Striga is a devastating parasitic both mutants had defects in apex of mutant haustoria, to understand the molecular weed that is particularly genes in the same pathway— and this was accompanied by mechanisms of this interaction problematic in sub-Saharan the signaling pathway of the continued activity of another in more detail, because many Africa, Europe and parts of Asia. hormone ethylene. “I couldn’t plant hormone, auxin. The basic questions remain,” says It is estimated to cause global believe we were that lucky,” mutant haustoria also proved Cui. “There may be more agricultural losses that exceed says lead author Songkui Cui, less effective at invading roots, specific processes we can US$1 billion. who has since moved to the sometimes failing to form eventually target.” Striga and other broomrapes Nara Institute of Science and invasive cells and instead invade plant roots using an Technology. continuing to elongate around infectious organ known as When the researchers the host root. Reference a haustorium (see image). treated P. japonicum plants Finally, the researchers 1. Cui, S., Kubota, T., Nishiyama, T., Ishida, J. K., To investigate haustorium with ethylene, they found that tested whether haustorium Shigenobu, S., Shibata, T. development, a team led by even a very small amount was development responds to F., Toyoda, A., Hasebe, M., researchers at the RIKEN enough to reduce the number ethylene from the host. Host Shirasu, K. & Yoshida, S. Center for Sustainable Resource of haustoria in normal plants, plants with defects in ethylene Ethylene signaling mediates host invasion by parasitic Science produced various but this effect was absent in the biosynthesis were infected plants. Science Advances mutants of the model broomrape ethylene-signaling mutants. 35% less than wild-type plants, 6, eabc2385 (2020).

SUMMER 2021 23 RESEARCH HIGHLIGHTS

RIKEN researchers have produced a quantum nanodevice that can behave both as an engine and a refrigerator— at the same time.

QUANTUM THERMODYNAMICS smaller devices, sometimes that the nanodevice could act based on single atoms. At these as either a heat engine or as Quantum nanodevice tiny scales, they have to account a refrigerator. But then they for quantum theory—the strange showed something far stranger— set of laws that says, for instance, the nanomachine could act as can simultaneously an electron can exist in two both at the same time, which is places at the same time or have a purely quantum effect. The do work and cool two different energies. Physicists researchers confirmed this by are developing new theoretical looking at the occupancy of A quantum nanodevice can simultaneously act frameworks and experiments to the upper energy level, which as a heat engine and a refrigerator try to work out how such systems combined to create a charac- will behave. teristic interference pattern. The quantum version of the “There was an almost perfect multitasking nanoma- cycle, the pools will exchange heat engine uses an electron match between the experimental A chine that can act as a heat energy and the system can be in a transistor. The electron interference pattern and that engine and a refrigerator at the used as either a heat engine or has two possible energy states. predicted by theory,” says Ono. same time has been created by a fridge. The team could increase or “This may allow rapid RIKEN engineers1. The device It would be impossible to set up decrease the gap between these switching between the two is one of the first to test how a macroscale machine that does energy states by applying an modes of operation,” Ono quantum effects, which govern both tasks simultaneously— electric field and microwaves. explains. “This ability could help the behavior of particles on the nor would engineers want to, “This can be analogous to the create novel applications with smallest scale, might one day be says Keiji Ono of the RIKEN periodic expanding–compress- such systems in the future.” exploited to enhance the perfor- Advanced Device Laboratory. ing operation of a fluid in a mance of nanotechnologies. “Combining a traditional heat chamber,” says Ono, who led Conventional heat engines and engine with a refrigerator would the experiment. The device also Reference refrigerators work by connecting make it a completely useless emitted microwaves when the 1. Ono, K., Shevchenko, S. two pools of fluid. Compressing machine,” he says. “It wouldn’t electron went from the high- N., Mori, T., Moriyama, S. & Nori, F. Analog of a quantum one pool causes its fluid to heat know what to do.” energy level to the lower one. heat engine using a single- up, while rapidly expanding the But things are different when By monitoring whether the spin qubit. Physical Review other pool cools its fluid. If these you shrink things down. Physi- upper energy level was occupied, Letters 125, 166802 (2020). operations are done in a periodic cists have been developing ever the team first demonstrated Martin© Steinthaler/Getty; lilographik/Getty ©

24 RIKEN RESEARCH RESEARCH HIGHLIGHTS

REGENERATIVE THERAPY reached three hair cycles when Itgβ5 was also bioengineered into the hair-follicle germ,” explains Regenerating hair in the lab first author Makoto Takeo. “In contrast, only 13% reached three By nourishing stem cells with just the right combination of nutrients, cycles when it was not present.” scientists have succeeded in growing hair that cyclically grows and falls out Analysis showed that these important cells are naturally located in the upper part of the ew clinical therapies for cultured them in 220 different whether stem cells cultured in the hair follicle’s bulge region. N hair regeneration could combinations of various biologi- NFFSE medium produce hair that “Our culture system estab- come from a recipe discovered by cal ingredients. They achieved grows in cycles, the researchers lishes a method for cyclical RIKEN researchers for realizing the highest rate of stem-cell placed bioengineered hair follicle regeneration of hair follicles continuous cyclical regeneration amplification in the shortest stem cells in NFFSE medium or from stem cells and will help of mouse hair follicles cultured time when they combined a in a medium lacking one of the make hair follicle regeneration from stem cells1. type of collagen with five factors factors and observed the regener- therapy a reality in the near Regenerative medicine, which called NFFSE medium. ated hair for several weeks. They future,” says Tsuji. exploits the ability of special cells found that 81% of hair follicles The team is hoping to find an known as stem cells to differenti- generated in NFFSE medium outside collaborator to help them ate into a wide variety of special- Our culture system went through at least three hair conduct clinic trials. “We are ized cells, is an exciting emerging cycles and produced normal hair. looking for a partner company field in modern medicine. A establishes a In contrast, 79% of follicles grown to help develop clinical applica- team led by Takashi Tsuji of the method for cyclical in the other medium produced tions,” says Tsuji. RIKEN Center for Biosystems regeneration of only one hair cycle. Dynamics Research has been Knowing that stem-cell working on ways to regenerate hair follicles from renewal can depend on what is Reference lost hair from stem cells. Now, attached to the outside of the 1. Takeo, M., Asakawa, K., stem cells Toyoshima, K., Ogawa, in an important step, they have cells, the researchers looked for M., Tong, J., Irié, T., identified a recipe for realizing markers on the surface of cells Yanagisawa, M., Sato, cyclical hair regeneration in the Since hair growth in mammals cultured in the NFFSE medium. A. & Tsuji, T. Expansion lab from a critical population of is a continuous cyclical process In addition to the expected CD34 and characterization of hair follicle stem cells harvested in which hair grows, falls out, and CD49f markers, they found epithelial stem cells with potential for cyclical hair from the skin. and grows again, a successful the best hair cycling was related regeneration. Scientific The researchers took fur and hair-regeneration treatment to the addition of Itgβ5. “We Reports 11, 1173 (2021). whisker cells from mice and must replicate this cycle. To test found almost 80% of follicles

The ability to use stem cells to grow hair that regenerates itself could lead to hair follicle regeneration therapy. © Gary John Norman/DigitalVision/Getty Gary John © Images

26 RIKEN RESEARCH FEATURES

Hunting for big game in physics with a small trap

An instrument designed to probe the imbalance between matter and antimatter could make the search for axions much, much more affordable.

he hunt for a hypothetical particle known as an axion, which would resolve some of the biggest problems in modern physics, could be made a lot easier using the sin- Tgle-particle detectors in Penning traps, a team led by Stefan Ulmer of the RIKEN Ulmer Fundamental Symmetries Laboratory has demonstrated1. First proposed in 1977, the axion was named after a washing powder brand because, if found, it has the potential to ‘clean up’ a vexing quantum mechanical problem. The strong CP problem is an issue with the strong nuclear force, the strongest of four fundamental forces of nature and the one that binds protons and neutrons together in atomic nuclei. However, it doesn't play according to the expected mathematical rules. “Many physicists are hunting for the axion at the moment,” says Jack Devlin, first author of the study and a member of the Baryon Antibaryon Symmetry Experiment (BASE) team at the European Organiza- tion for Nuclear Research (CERN). “If we could con- vincingly detect axions, it would be huge—the biggest physics you can think of. It would answer some of the most fundamental questions.”

SETTING A TRAP FOR AXIONS

SPRING 2020 27 FEATURES

Measurement trap: A region PENNING TRAP PRECISION where the magnetic and A photograph of the Penning trap used as part of the search for electric fields are controlled axions. Voltages are applied to the gold-coated, ring-shaped very precisely to make highly electrodes, trapping antiprotons. The antiprotons are used to accurate measurements of characterize the superconducting detection circuit. the frequencies at which the antiprotons move about.

Storage trap: Stores trapped ions.

them that might hint at the reason for the imbalance. But it struck them that they could use the same mystery in modern physics, namely why matter seems equipment to search for the axion. While, in theory, to be in much greater supply than antimatter when axions are dark and don’t interact with normal particles the present theory predicts they should be present in except via gravity (the weakest of the four fundamental exactly equal amounts. forces), theory predicts that when placed in a strong All fundamental particles have an antiparticle. For magnetic field, an axion will decay into a photon of example, the electron’s antiparticle is the positron, but light once in a blue moon. This gives experimentalists there are far more electrons than positrons around us, an opportunity to spot telltale signs of axions in the lab. and far more matter than antimatter. That’s where Ulmer’s Penning traps, based at CERN According to the most accurate experimental mea- in Switzerland, can help. Penning traps are operated surements, the binding nuclear force in atomic nuclei in the highly uniform magnetic fields provided by remains identical when you swap every particle with superconducting coils. Using a roughly two-meter- its antiparticle and reflect everything in a mirror. long instrument, Ulmer’s team was able to determine But that goes against the theory that gave birth to the constraints on the rate at which axions turn into standard model of particle physics, which has been photons for a narrow range of axion masses, effec- such a success in every other test thrown at it. tively narrowing the search. Ulmer’s team has been using the Penning trap to The beauty of this demonstration is that it was at perform measurements on protons and antiprotons a fraction of the cost of equivalent observations by

28 RIKEN RESEARCH FEATURES

This feature looks at the work of STEFAN ULMER

Chief Scientist Stefan Ulmer leads the Ulmer Fundamental Symmetries Laboratory at RIKEN. He is also the founder of the BASE collaboration at the European particle- physics laboratory CERN in Switzerland. BASE Part of the copper tube that surrounds performs high-precision the trap electrodes, measurements of helping to maintain protons and antiprotons an ultrahigh vacuum. to better understand matter and antimatter symmetry. Some of their experiments have had unprecedented sensitivity, including (IAXO), built from an almost 10-meter-long decom- the axion measurement was a doddle. “The data for magnetic moments, missioned superconducting test magnet for the taking was simple—I mean, really straightforward,” which allowed the first Large Hadron Collider, also based at CERN. Ulmer says. Despite the simplicity of the measure- ever observation of "And if our resonant single-particle detectors ment, the demonstration attracted a lot of interest. proton and antiproton were purpose-built to search for axions, it could “I’m really surprised at the discussion this study spin quantum transitions. Using their Penning search a much greater area with higher sensitivity,” has generated,” Ulmer says. “The axion physics traps, his group has says Ulmer. community is extremely interested in this project.” performed several world- When asked how he would celebrate if his team record measurements, CLEANING UP TWO PROBLEMS found the axion, Ulmer says that at the very least he including one for WITH ONE PARTICLE would break open a bottle of champagne. He also precision in charge– The presence of the hypothetical axion, which notes the internal conflict when performing such parity–time invariance should be at least 50,000 times lighter than the measurements, “On the one hand, you measure in the baryon sector by comparing proton/ electron, would solve the strong CP problem. Some basically expecting to find nothing because you antiproton charge-to- think it could also actually be the hypothetical want to avoid bias. But on the other hand, you really mass ratios. Recently, substance known as dark matter. hope that you will find something that will revolu- the lab has started using The axion is also a highly attractive candidate for tionize physics.” antiproton spins as the enigmatic dark matter that is believed to make up dark-matter antennas 85% of the Universe’s mass. Astrophysicists know that REFERENCE and single-particle Penning trap detectors dark matter is out there because the outer regions of 1. Devlin, J. A., Borchert, M. J., Erlewein, S., as antennas for axion-to- galaxies are spinning faster than if galaxies were just Fleck, M., Harrington, J. A., Latacz, B., Warncke, photon conversion. composed of normal matter. But since none of the J., Wursten, E., Bohman, M. A., Mooser, A. H. elementary particles in the standard model of particle et al. Constraints on the coupling between physics fits the properties of dark matter, physicists axionlike dark matter and photons using an are searching for exotic particles such as the axion. antiproton superconducting tuned detection Compared to the highly demanding single-par- circuit in a cryogenic Penning trap. Physical

SUMMER 2021 29 PERSPECTIVES

AI OF THE STORM During the pandemic, RIKEN’s artificial intelligence teams have been able to advance everything from travel advice to online medicine. Has COVID-19 unlocked Japan’s big data doors?

he old-fashioned sense of ‘pulling together’ manage social security, taxation and disaster-response that occurred during the SARS-CoV-2 information. However, uptake of the cards in Japan crisis may in fact help reshape the trajec- has been low and the system was plagued by problems tory of Japan’s artificial intelligence (AI) when last year the government tried to distribute Tresearch by opening the door to better data sharing. stimulus money through it to combat the effects of For example, I believe the basis for progress toward the pandemic. a truly digital society in Japan will be an effective In October 2020, Japanese Prime Minister universal digital ID system. And indeed, in 2020, Yoshihide Suga announced that his government Japan’s national digital ID system was the topic of would be creating a special agency devoted to digitiza- much discussion. Twelve-digit, chipped ‘My Number’ tion. Official statements followed about increasing My

cards have been available in Japan since 2016 and help Number card uptake and expanding the system’s © Mustafa Maki / EyeEm / Getty Images; kontekbrothers / Getty Images

30 RIKEN RESEARCH PERSPECTIVES

uses, including to insurance, and to data on med- with deep phenotyping based on information ication and medical costs via the government-run geometry, RIKEN has already developed algorithms Mynaportal website. that can help determine who is at risk of mortality Many AI researchers are cheering. For a number and aggravation from COVID-19. Now the group of years, it had been evident that while a focus on will train these algorithms further using fresh THL individual achievement has created some very suc- clinical data. The THL data comes from up to 1,000 cessful scientific cultures, it has hindered widespread patients with positive COVID results drawn from personal data sharing and the next big leaps forward their COVIDprog project, a study originally aiming in science. to identify the individual characteristics, including AI researchers argue that big data drawn from underlying genetics, that affect COVID-19 outcomes. digitized personal information—if shared in secure, This information will be processed securely through ethical ways—will drive huge and important advances BC-Platforms technology. in everything from medical diagnostics to disaster RIKEN-developed machine learning is also being MICHIHIKO MINOH management. That’s not to say that some data privacy used to help tailor online information delivery to an RIKEN Executive concerns aren’t valid, but just that the advantages of a individual’s traits to improve reductions in high-risk Director, Director of digitized, data-rich society may far outweigh the risks. public-health behaviors. This project harnesses the RIKEN Information results of various studies in preventive medicine and R&D and Strategy POWERING THROUGH THE PANDEMIC behavioral economics. Abusive language and disinfor- Headquarters Big data, high-powered computing and artificial intel- mation related to the COVID-19 is also being tracked Michihiko Minoh is ligence managed largely through the RIKEN Center at RIKEN via natural language processing technology, director of the RIKEN for Advanced Intelligence Project (AIP) and the so that interventions can be targeted at sources or Information R&D and RIKEN Center for Computational Science (R-CCS) during peaks. Strategy Headquarters were key to how the scientific community in Japan (R-IH) and leads RIKEN’s addressed the pandemic, for example. SOCIALLY DISTANCED SCIENCE Guardian Robot Project as the part of R-IH. He A number of RIKEN teams have designed and During the pandemic, remote medical check-ups became an Executive trained AI algorithms that do everything from became preferable to many. As a result, the AIP’s Director at RIKEN in visualizing the risks around travel routes and virus Science, Technology and Society Team is taking a April 2018. Previously transmission to simulating individual infections and fresh look at the classifications and the ELSI (Ethics, he served as director of economic activity. Legal and Social Issues) of online initial medical the Academic Center for Many researchers are using a secure personal-data examinations in Japan. Computing and Media Studies from 2006 to management technology developed in Japan, called To remotely support older adults in cognitive 2010 and concurrently the Personal Life Repository (PLR). PLR technology decline, the Cognitive Behavioral Assistive Tech- served as vice director encrypts personal data in such a way that only the nology Team at the AIP has continued to develop in the Kyoto University user can manage it, and only those whom the user an AI-based communication and dialogue support President’s Office from explicitly permits can decrypt and add to a person’s system for use by aged-care and healthcare providers. 2008 to 2010. From 2010 PLR. Even the cloud storage service providers This RIKEN-developed AI uses images collected to 2016, he was chief information officer and involved in the system cannot decrypt PLR informa- during the day by older or cognitively compromised director-general at the tion. This type of system could improve on standard adults to help prompt group discussion, conversa- Institute for Information service provider supplied records, as it makes the tional participation and active recall, which helps Management and information easy to locate and is likely to drive elec- protect against dementia and further deterioration. Communication at tronic record system development that is more univer- The idea is that the AI helps the group maintain Kyoto University. sally transferable. strict rules that balance listening and speaking. More PLR records could, for example, eventually add recently, as group setting have become more limited, much to the work of the Business and Economic a chat bot system called the Text-oriented Artificial Information Fusion Analysis Team at the AIP, who Chat Operation System (TACOS) was shown to be have begun to try to predict COVID-19 infection able to provide conversational support services for up severity in Japan, especially among younger people. to 40 solo users in real time. They are currently training their algorithms on Meanwhile, the AIP’s Technology and Society Team legally secured data from health insurance claims and is monitoring for the potential drawbacks of remote medical check-ups using new data-fusion techniques communication, particularly at work. The project and statistical machine learning methods. has already surveyed 300+ people to investigate the This will complement AI modeling work through impacts of telework and identify working styles that the RIKEN Medical Sciences Innovation Hub mitigate negative outcomes, such as a lack of delinea- Program, which is being used to develop a personal- tion between work and home. ized prediction system for COVID-19 in collaboration In addition, the Decentralized Big Data Team at the with the Finnish Institute for Health and Welfare AIP are investigating formats and user interfaces that

SUMMER 2021 31 PERSPECTIVES

science to improve robotic knowledge acquisition and dialog, psychological processing, interactivity, multi- PANDEMIC PROMTS INCREASED DIGITIZATION Government 'My Number’ cards have been available since 2016 to help streamline services, modal data recognition, man–machine collaboration including social security, taxation and disaster response. The first pandemic outbreaks in and behavior learning. early 2020 renewed interest in these digital efficiencies. In September 2020, the Suga For example, the project will use cognitive government issued a points reward system to promote uptake of the card. In April 2021, roughly 28% of the population had a card. The aim is full uptake by March 2022. modeling to build robotic software that helps provide adaptive and situationally responsive problem solving. It will also work to link sensors and actuators to these Total cards issued systems to facilitate high-level planning, prediction 40 and reflection systems. The program is also working Estimated to develop the ability of its robots to understand 30 natural language and to speak to their users.

JAPAN’S AI FUTURE 20 Overall, digitally savvy populations initially fared well during the pandemic, which will be another driver of Cards (millions) 10 digitization in Japan. In Taiwan, for example, Audrey Tan, the minister in charge of digital affairs, launched a successful mobile site to prevent the hoarding of 0 masks. South Korea, which has the highest penetra- 03/2017 03/2018 03/2019 03/2020 03/2021 tion of smartphones in the world, also had initial Card ownership success controlling the pandemic with very precise 100 infection tracing technology. These examples, and Targeted others, have motivated many governments to re-ex- The Japanese government 80 aims to have a My Number amine their digital infrastructure. Card issued for every In addition, the AI market is also set to boast a 60 resident by ﬁscal year 2022. compound annual growth rate between 2018 and 2025 of anywhere between 33% to 55%, with Asia 40 anticipated to overtake North America’s number one spot in the global market by 2025. Japan is currently Ownership rate (%) 20 number one in the world as a supplier of industrial robots and third, after China and the USA, in AI 0 R&D. Toshiba is Japan’s highest AI patent contribu- 03/2017 03/2018 03/2019 03/2020 03/2021 03/2022 tor, claiming the world’s third spot, right after IBM and Microsoft. On top of all of this, more than 40% of Japan will be elderly by 2030. This puts pressure on the labor force write in digital environments, as the pandemic and healthcare system, but it is also an incentive to is deemed to have accelerated digitization. They develop AI-enhanced care and industrial robots. And are also looking into AI technologies that assist while the pandemic has caused a slowdown in some composition, comprehension and other advanced sectors, it has also sparked AI-driven solutions and uses of digital documents. motivated faster digitalization. Overall, the outlook seems stronger than ever for SUPPORTED BY ROBOTS Japanese AI researchers, although there is much work The COVID-19 outbreaks have also highlighted to be done. One caution I will put forth is that if a gen- robotic technology’s usefulness in facilitating social eralized negative attitude about data sharing holds us distancing. Robots, for example, are particularly back from collecting relevant information, countries promising prospects as carers to vulnerable popula- with less individually oriented cultures may overtake tions, such as the elderly. us in key sectors such as AI healthcare, where careful, I lead the Guardian Robot Project, which is devel- sensitive data input is crucial. Ethical considerations oping next-generation robots. The project, run and data privacy are of course important and RIKEN through the RIKEN Information R&D and Strategy adopts best-practice technology, but the level of data Headquarters and Innovation Hub, is developing sharing within a population may simply boil down to a robot that can autonomously recognize its envi- a feeling of safety or personal preference. Nonetheless, ronment and the state of the person it is supposed we are also partnering with our neighbors on many to support. Five teams are using AI trained on data projects, and are excited about where these collabora-

obtained from psychology, brain science and cognitive tions will go. Ministry Affairs INternal CommunicationsSource: and of

32 RIKEN RESEARCH RIKEN’S CENTERS AND FACILITIES across Japan and around the world

LEGEND (RIKEN’s Headquarters) WAKO ● Strategic Research Center ● Center for Emergent Matter Science (CEMS) ■ Research Infrastructure Center ● RIKEN Center for Quantum Computing (RQC) ◆ Large Research Infrastructure ● Center for Sustainable Resource Science (CSRS) ▲ Research Cluster ● Center for Brain Science (CBS) ▼ Information Research and ● Interdisciplinary Theoretical and Infrastructure Mathematical Sciences Program (iTHEMS) ● RIKEN Nishina Center for Accelerator-Based Science (RNC) ● RIKEN Center for Advanced Photonics (RAP) ▲ RIKEN Cluster for Science, Technology, and Innovation Hub (RCSTI) ▲ Cluster for Pioneering Research (CPR) ◆ Radio Isotope Beam Factory (RIBF) ▼ RIKEN Information R&D and Strategy Headquarters (R-IH) SENDAI ● Center for Advanced Photonics (RAP) YOKOHAMA ● Center for Sustainable Resource Science (CSRS) ● Center for Integrated Medical Sciences (IMS) TSUKUBA ■ ● Center for Biosystems Dynamics Research (BDR) BioResource Research ■ RIKEN Center for Computational Science (R-CCS) Center (BRC) ◆ ▲ RIKEN Cluster for Science, Technology, and Innovation BioResource Hub (RCSTI) ◆ Genome Sequencing ◆ Nuclear Magnetic Resonance (NMR) ▼ RIKEN Information R&D and Strategy Headquarters (R-IH) TOKYO ● Center for Advanced Intelligence Project (AIP) ▼ Innovation Design Office HARIMA NAGOYA ▼ RIKEN Information R&D ■ RIKEN SPring-8 and Strategy Headquarters Center (RSC) (R-IH) ◆ SPring-8 ◆ SACLA KEIHANNA ■ BioResource Research Center (BRC) ● Center for Advanced Intelligence Project (AIP) ▼ Guardian Robot Project (R-IH)

KOBE ● Center for Biosystems Dynamics Research (BDR) OSAKA ■ RIKEN Center for Computational Science (R-CCS) ● Center for Biosystems ◆ Molecular Imaging Dynamics Research (BDR)

Since relocating its original campus from central Tokyo Singapore and other countries. To expand our network, to Wako on the city’s outskirts in 1967, RIKEN has rapidly RIKEN works closely with researchers who have returned to expanded its domestic and international network. their home countries or moved to another institute, with help RIKEN now supports five main research campuses in Japan from RIKEN’s liaison offices in Singapore, Beijing and Brussels. and has set up a number of research facilities overseas. In addition to its facilities in the United States and the United For more information, please visit: Kingdom, RIKEN has joint research centers or laboratories www.riken.jp/en/research/labs/ in Germany, Russia, China, South Korea, India, Malaysia, www.riken.jp/en/collab/research/ www.riken.jp/en

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