Memory Asymmetry: A Key to Convergence in Zero-Sum Games

This study provides a new convergence mechanism in learning in games. Learning in games considers how multiple agents maximize their own rewards through repeated plays of games. Especially in two-player zero-sum games, where agents compete with each other for their rewards, the reward of the agent depends on the opponent's strategy. Thus, a critical problem emerges when both agents learn their strategy following standard algorithms such as replicator dynamics and gradient ascent; their learning dynamics often draw cycles and cannot converge to their optimal strategies, i.e., the Nash equilibrium. We tackle this problem with a novel perspective on asymmetry in learning algorithms between the agents. We consider with-memory games where the agents can store the played actions in their memories in order to choose their subsequent actions. In such games, we focus on the asymmetry in memory capacities between the agents. Interestingly, we demonstrate that learning dynamics converge to the Nash equilibrium when the agents have different memory capacities, from theoretical and experimental aspects. Moreover, we give an interpretation of this convergence; the agent with a longer memory can use a more complex strategy, endowing the utility of the other with strict concavity.Comment: 11 pages & 5 figures (main), 4 pages & 1 figure (appendix

On the improvement performance of a dual rotor segment type SRM

A dual rotor segment type switched reluctance motor (SRM) is proposed for flat configuration. It has toroidal stator coil and has inner rotor as well as outer rotor. The performance characteristics are calculated using finite element method. On a flat type SRM, leakage flux is greatly generated at both side coil. To reduce the leakage flux we propose shield structure. Effectiveness of the shield structure is verified analytically.2013 IEEE 10th International Conference on Power Electronics and Drive Systems, PEDS 2013; Kitakyushu; Japan; 22 April 2013 through 25 April 201

COMPARISON OF THE ABUNDANCE OF PREY ANIMALS FOR ORIENTAL STORKS IN A BIOTOPE AND LOTUS FIELDS IN NARUTO CITY, TOKUSHIMA PREFECTURE, JAPAN.

本研究では，鳴門市に造成されたビオトープが，コウノトリの餌場として機能するかを明らかにするため，周囲の飛来回数の異なるレンコン田とコウノトリの餌生物量を比較した．餌生物は，すくい採りとペットボトルトラップによって採集した．調査の結果，ビオトープで採集された餌生物の湿重量は，コウノトリの飛来回数が多いレンコン田より小さかった．レンコン田で採集された生物は，アメリカザリガニやウシガエルといった外来種が大半を占めた．これらの生物はコウノトリの主要な餌となり得るが，在来種を捕食するなど，在来生態系に負の影響を与えることが懸念される．今後のビオトープ管理においては，在来種の生息に適した環境づくりとともに，外来種の侵入・拡大防止を両立する取り組みが重要であると考えられた．In order to clarify whether the biotope created in Naruto City functions as a feeding sites for storks, this study compared the amount of stork prey in a lotus root field and a biotope created with different numbers of storks flying to the field. Prey organisms were collected by scooping and plastic bottle traps. The results showed that the wet weight of prey organisms collected in the biotope was smaller than that in the lotus root fields, where the storks visited more frequently. The majority of organisms collected in the lotus root fields were non-native species such as American crayfish and bullfrogs. These organisms are the main food source for storks, but there is concern that they may have a negative impact on native ecosystems, for example, by preying on native species. In future biotope management, it is important to create an environment suitable for habitat of native species as well as to prevent the invasion and spread of non-native species

Intersatellite-link demonstration mission between CubeSOTA (LEO CubeSat) and ETS9-HICALI (GEO satellite)

LEO-to-GEO intersatellite links using laser communications bring important benefits to greatly enhance applications such as downloading big amounts of data from LEO satellites by using the GEO satellite as a relay. By using this strategy, the total availability of the LEO satellite increases from less than 1% if the data is downloaded directly to the ground up to about 60% if the data is relayed through GEO. The main drawback of using a GEO relay is that link budget is much more difficult to close due to the much larger distance. However, this can be partially compensated by transmitting at a lower data rate, and still benefiting from the much-higher link availability when compared to LEO-to-ground downlinks, which additionally are more limited by the clouds than the relay option. After carrying out a feasibility study, NICT and the University of Tokyo started preparing a mission to demonstrate the technologies needed to perform these challenging lasercom links. Furthermore, to demonstrate the feasibility of this technique, an extremely-small satellite, i.e. a 6U CubeSat, will be used to achieve data rates as high as 10 Gbit/s between LEO and GEO. Some of the biggest challenges of this mission are the extremely low size, weight and power available in the CubeSat, the accurate pointing precision required for the lasercom link, and the difficulties of closing the link at such a high speed as 10 Gbit/s.Comment: 5 pages, 10 figures, 3 table

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Validation of a Strategy for Cancer Therapy: Delivering Aminoglycoside Drugs to Mitochondria in HeLa Cells

Mitochondria in human cancer cells have been implicated in cancer cell proliferation, invasion, metastasis, and even drug-resistance mechanisms, making them a potential target organelle for the treatment of human malignancies. Gentamicin (GM), an aminoglycoside drug (AG), is a small molecule that functions as an antibiotic and has ototoxic and nephrotoxic characteristics. Thus, the delivery of GM to mitochondria in cancer cells would be an innovative anticancer therapeutic strategy. In this study, we attempted mitochondrial delivery of GM in HeLa cells derived from a human cervical cancer. For the mitochondrial delivery, we used MITO-Porter, a liposomal nanocarrier for mitochondrial delivery via membrane fusion. We first encapsulated GM in the aqueous phase of the carrier to construct GM-MITO-Porter. Flow cytometry analysis and fluorescent microscopy observations permitted us to confirm that the GMeMITO-Porter was efficiently taken up by HeLa cells and accumulated in mitochondria, whereas naked GM was not taken up by the cells. Moreover, cell viability assays using HeLa cells showed that the GMeMITO-Porter induced strong cytotoxic effects related to mitochondrial disorder. This finding is the first report of the mitochondrial delivery of an AG to cancer cells for cancer therapeutic strategy. (C) 2016 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved

In Vivo Transgene Expression in the Pancreas by the Intraductal Injection of Naked Plasmid DNA

Patients with type I diabetes, which is caused by the destruction of pancreatic islets, now require regular therapeutic injections of insulin. The use of transgene therapy represents an alternate and potent strategy for the treatment of type I diabetes. However, only a limited number of studies regarding in vivo gene delivery targeting the pancreas and islets have been reported. Here, we report on the possibility of in vivo transgene expression in the pancreas by the intraductal injection of naked plasmid DNA (pDNA). Gene expression activities were detected in the pancreas of mice after the injection of naked pDNA encoding luciferase into the common bile duct. We then investigated the effects of injection dose, volume, and speed on gene delivery and determined the optimal conditions for the delivery of pDNA to the pancreas. Exogenous luciferase mRNA was detected in the pancreatic islets by reverse transcription PCR analysis. Moreover, no injury was detected in the liver, the common bile duct, or the pancreas over time after the injection. These findings indicate that the intraductal injection of naked pDNA promises to be a useful technique for in vivo gene delivery targeted to pancreatic tissue and islets. (c) 2018 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved