早稲田大学 21世紀COEプログラム多元要素からなる自己組織系の物理


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∥１9年度(2007年度)∥
∥１8年度(2006年度)∥∥17年度(2005年度)∥∥16年度(2004年度)∥∥15年度(2003年度)∥

ＣＯＥシンポジウム
	第５回自己組織系物理国際シンポジウム　講師　Pierre Gaspard(Université Libre de Bruxelles, Belgium) 他　日程　９月１３日（木）-１４日（金）　場所　早稲田大学国際会議場井深ホール　　講師　Pierre Gaspard(Université Libre de Bruxelles, Belgium) 　　　　　　Yoshitsugu Oono (Univ. Illinois, USA) 　　　　　　Bei-Lok B. Hu (Univ. Maryland, USA) 　　　　　　Shin-ichi Uchida (Univ. Tokyo) 　　　　　　他 ※プログラムはこちらのページをご覧ください。 Symposium Program ※日本語の予定表はこちら Symposium Program （日本語）

ＣＯＥノーベルレクチャー
	第３回ＣＯＥノーベルレクチャー　　講師　ロデリック・マッキノン教授（米国ロックフェラー大）　　　　　　　2003年ノーベル化学賞受賞　　日程　１０月１２日　１５：００－１７：００　　場所　62号館W棟大会議室　　タイトル　Mechanism of Voltage-Dependent Gating アブストラクト： Ion channels are responsible for generating electrical impulses and mediating numerous cellular processes. To accomplish their tasks in biology ion channels must exhibit two basic properties, selectivity and gating. Recent developments on the molecular principles of selectivity and gating in K channels will be presented.

　ＣＯＥワークショップ

第7回ＣＯＥワークショップ 　
　共催　研究会「ドメイン成長のモデリング　－バクテリア・結晶に着目して－」
　講師　小田切健太（東京大学）、松下貢（中央大学）、飯島徹也
　　　　（中央大学）、山崎義弘（早稲田大学）
　日程　２００８年１月２３日（水）
　場所　５５号館Ｓ棟２階　第４会議室
　時間　１３：３０－１８：００
　紹介教員　山崎義弘
　趣旨
バクテリアのコロニー形成や結晶成長などの「ドメイン成長現象」については、これまで、反応拡散方程式やセルオートマン法に基づく様々なモデルが提案されてきた。このようなモデル構築の利点は、観察により抽出された「ドメインの形成様式」をモデルにおける時間発展のルールとして取り入れやすい点にある。しかしながら、この利点は、様式の抽出過程における恣意性がモデルの中に入り込みやすいという欠点もはらんでいる。
本研究会では、実験事実との対応に重点を置き、モデル構築の際に潜む恣意性の除去、および、種々な手法に基づいたモデル間の対応関係についての意見および知見の交換を行う。

13:30-13:35　はじめに
　13:35-14:50 自己増殖反応系におけるパターン形成とダイナミクス：離散的･確率的ダイナミクスが引き起こす多様なパターン形成
　　　　　　　　　小田切健太氏（東京大学）　
　15:00-16:15 バクテリアのコロニー形成－実験とモデル化－
　　　　　　　　　松下貢氏（中央大学）
　16:25-17:10 セルオートマトン法によるバクテリアコロニーのモデリング
　　　　　　　　　飯島徹也氏（中央大学）
　17:20-18:00　アスコルビン酸の結晶成長
　　　　　　　　　山崎義弘氏（早稲田大学）

第６回ＣＯＥワークショップ 　
　講師　Prof. Schneider(École Polytechnique Fédérale de Lausanne)
　　　　　Prof. Varga(Vienna University of Technology)
　　　　　Prof. Altman (Hong Kong University of Science and Technology)
　日程　２００８年１月２１日（月）
　場所　５５号館Ｓ棟２階　第４会議室
　時間　１４：３０−１８：３０
　紹介教員　大島忠平
アブストラクト：
Prof. Schneider
Recent advances in low-temperature scanning tunnelling microscopy and spectroscopy (STM, STS) have provided new opportunities for investigating locally chiral recognition phenomena and supramolecular self-assembly.
Two examples are chosen, which illustrate the power and the potential of this local approach. (i) Combining STM observations and manipulations with first-principle electronic structure calculations, 1-nitronaphthalene molecules are found to become pseudo-chiral upon adsorption. The chirality of the individual molecules is determined from high resolution STM images which closely reflect the asymmetric electronic structure of the molecules. Hydrogen bonds are at the origin of their self-assembly into two-dimensional supramolecular clusters and chains.¹ The separation of a racemic mixture of two-dimensional molecular clusters is achieved by the tip of an STM.² A real space observation of a coverage-driven chiral phase transition from a conglomerate to a racemate at low and high molecular coverages, respectively, is presented.³ (ii) Conservation of chirality in a hierarchical supramolecular self-assembly of pentagonal symmetry of the organic molecule rubrene on a reconstructed Au(111) surface has been observed recently.⁴ We show the spontaneous chiral resolution of the racemate into disjoint homochiral complex architectures and demonstrate the ability to monitor directly the evolution of chiral recognition processes on the molecular and supramolecular level. We are able to probe and to locally modify the intrinsic electronic structure and the conformation of the supported nonplanar molecules.⁵
The work was supported by the Swiss National Science Foundation.
[1] M. Böhringer, K. Morgenstern, W.-D. Schneider, R. Berndt, F. Mauri, A. De Vita, R. Car, Phys. Rev. Lett., 1999, 83, 324.
[2] M. Böhringer, K. Morgenstern, W.-D. Schneider, R. Berndt, Angew. Chem. Int. Ed., 1999, 38 , 821.
[3] M. Böhringer, W.-D. Schneider, R. Berndt, Angew. Chem. Int. Ed., 2000,39, 792.
[4] M.-C. Blüm, E. Cavar, M. Pivetta, F. Patthey, and W.-D. Schneider, Angew. Chem. Int. Ed., 2005, 44 , 5334.
[5] M.-C. Blüm, M. Pivetta, F. Patthey, and W.-D. Schneider, Phys. Rev. B, 2006, 73, 195409.

Prof. Varga
We have investigated the structure and morphology of several metal clusters grown on alumina films on NiAl(110) [1] and Ni₃Al(111) [2] respectively with scanning tunneling microscopy. For NiAl(110) we found for many metals that the nucleation takes place at step edges and domain boundaries and the thermodynamically favorable shape of the cluster is one with a steep slope and rounded top. Truncated spheres with a high contact angle can approximate this shape. Only for Pd at room temperature, growth is kinetically limited and Pd forms mostly facetted islands which transform towards the thermodynamically favorable shape after annealing to 300 °C.. The low work of adhesion, somewhere around 1.5 J/m² for Co and approximately 1 J/m² for the Pd clusters, calculated from the contact angles supports the finding that both metals are wetting the alumina film badly.
The structure of the alumina oxide on Ni3Al(111), which has been solved recently exhibits holes at the corner of the (V67xV67)R 12.2o unit cell, reaching down to the metal substrate. These holes are large enough to trap atoms of any kind of metal. Therefore , the ultra-thin oxide film, forming a nano-mesh, should be a perfect template for growing highly regular arranged metal cluster. It has been observed that only Pd atoms nucleate exclusively at the corner holes and, hence , show a perfect hexagonal arrangement. Fe and Co clusters grow on other local defects without showing the regularity of Pd clusters. By pre-deposition of a Pd seed layer, however, we can create a metallic nucleation site on each corner hole and Fe as well as Co clusters form a well ordered hexagonal arrangement on the oxide nano-mesh.
[1] E. Napetschnig, M. Schmid, and P. Varga, Surf. Sci. 601 (2007) 3233
[2] M. Schmid, G. Kresse, A. Buchsbaum, E. Napetschnig, S. Gritschneder, M. Reichling, P. Varga Phys. Rev. Lett. 99 (2007) 196104

Prof. Altman
Vacuum tunneling from sharp W tips has long been exploited in the past to generate bright, coherent electron beams by field emission and to obtain atomic resolution in scanning tunneling microscopy (STM) and spectroscopy of surfaces. Spin polarized electron tunneling in field emission and STM has also been achieved previously from W tips coated with ferromagnetic and antiferromagnetic thin films. In the present work, ultrathin films are grown on refractory metal surfaces as the basis for spin polarized vacuum tunneling. Growth and magnetism are characterized on macroscopic surfaces using low energy electron microscopy (LEEM) and spin polarized LEEM. Spin polarization of field emitted electrons from Co/W(111) and Fe/W(100) tips has been measured using a compact high-efficiency retarding potential Mott polarization analyzer. Until now, only moderate polarization of 20-35% has been observed. Transverse spin polarization directions in field emission are consistent with in-plane magnetization and symmetry that are observed in films on macroscopic surfaces. Polarization manipulation has also been achieved by application of transverse magnetic field pulses and by thermally assisted spontaneous magnetization flipping. Investigations of spontaneous superparamagnetic flipping behavior provide insight on the fundamental limits of spin polarized vacuum tunneling from ferromagnetic film coated tips.


14:30-15:30   A Local View on Chirality　
                    Prof. Schneider  École Polytechnique Fédérale de Lausanne 
(EPFL)、Switzerland

15:30-   15:30-16:30   Well Ordered Metal Clusters on Alumina Film 
Vienna                      Prof. Varga ViennaUniversity of Technology, Austria

16:30-17:30   Spin polarized-electron emission 
                    Prof. Altman Hong Kong University of Science and Technology、Hong kong 
17:30-18:30   Summary and Discussions

第５回ＣＯＥワークショップ 　
　共催　強相関電子物性研究ミニ研究会
　　　　　「層状コバルト酸化物の物性と物理」
　講師　黒木和彦（電気通信大学）、藤井武則（東京大学）、寺崎一郎
　　　　　　（早稲田大）
　日程　１１月１３日（火）
　場所　大久保キャンパス 51号館3階第5会議室
　時間　１５：００－１８：００
　 ※詳細はこちらのページをご覧ください。
       Program

第４回ＣＯＥワークショップ 　
　共催　早稲田大学COE「多元要素からなる自己組織系の物理」
　　　　　「アクチン・ミオシン：分子と細胞を如何にして結び付けるか」
　講師　鈴木団（早稲田大学）、藤田英明（東北大学）、中野賢太郎（筑波大）他
　日程　１１月１０日（土）
　場所　早稲田大学理工学術院大久保キャンパス 55号館N棟1階大会議室
　時間　１２：３０－１９：００
　 ※詳細はこちらのページをご覧ください。
       Program

第２回ＣＯＥワークショップ 　
　講師　Jean-Michel KIAT
　　　　　　（フランス、エコール・サントラル・パリ、物性研究所(SPMS)所長）
　　　　　 Charlotte Malibert
　　　　　　（エコール・サントラル・パリ物性研究所研究員）
　日程　１０月２２日（月）
　場所　55号館N棟２階物理学科応用物理学科会議室
　時間　１０：００－１３：００
　タイトル
　　(JMK) From the structure of relaxors to the structure of morphotropic
　　phase boundary compounds, application to nano powders and
     nanoceramics.
　　(CM) Origin of temperature evolution of lattice strains in thin films of
　　ferroelectric compounds : example of PSN-PT films.
　アブストラクト：TBA

第３回ＣＯＥワークショップ（協賛）　
　主催　早稲田大学各務記念材料技術研究所
　協賛　早稲田大学COE「多元要素からなる自己組織系の物理」
　早稲田大学各務記念材料技術研究所(材研)
　2007 年度教育プログラム
　教育基礎講座
　「強相関電子材料開発の新展開」・連続講座
　１．開講期間：１１月２日(金) ９日(金) 　計２回
　２．開講時間：１３：００－１７：３０
　３．会場：早稲田大学各務記念材料技術研究所講演室 (材料技術研究所
　キャンパス 42-1 号館　1階)
※プログラム・申し込みはこちらをご覧下さい。
　http://www.f.waseda.jp/katsuf/Takuro/2007_ZAIKEN_program.pdf

2007年度第１回ＣＯＥワークショップ　
　早稲田２１COEコロキウム
「New Approaches to Phenomena Originated from Heterogeneity in    Ferroelectrics and Related Materials」
　講演者：M. Glazer (Oxford Univ. UK)、P. A.Thomas (Warwick Univ. UK)、
              T.Shigenari（Waseda Univ., Univ. Electro-Commun.）
              K.Hirota (ISSP, Tokyo Univ.)、T.Katsufuji (Waseda Univ.)
　日程　４月７日（土）
　場所　早稲田大学理工学術院　62号館１階大会議室　アクセス
　時間　１０：３０－１５：００

　10:25   Introductory Y.Uesu
　10:30-11:30 The Morphotropic Phase Boundary -My Part in its Downfall-
                   M. Glazer (Oxford Univ. UK)
　11:30-12:30 Ferroelectric Domains Studied by X-ray Imaging　
　　　　　　　　　 P. A.Thomas (Warwick Univ. UK)
　12:30-13:30 Lunch
　13:30-14:00 Soft Mode in the Ferroelectric Phase of Isotope Substituted SrTi18O3.
　　　　　　　　　 T.Shigenari（Univ. Electro-Commun., Waseda Univ.,）
　14:00-14:30 Controlling Heterogeneity in Relaxors -- Neutron and X-ray scattering of PMN-xPT and PIN
     　　　　　　 K.Hirota (ISSP, Tokyo Univ.)
　14:30-15:00 Orbital Ordering in Spinel Vanadates
                   T.Katsufuji (Waseda Univ.)
　

ＣＯＥセミナー
	第１４回ＣＯＥセミナー　NEW!! 　　　講師　若林克三（大阪大学基礎工学部名誉教授）　　演題　シンクロトロン放射X線回折／散乱による筋収縮の分子メカニックスと構造変化（Molecular mechanics and structural changes of the actin and myosin filaments in muscle contraction, studied by synchrotron X-ray diffraction and scattering）　　日程　３月１１日(火)　１６：００－１７：３０　　場所　55号館N棟第２階　物理・応物会議室　　紹介教員　石渡信一アブストラクト： 1990年に入って筋収縮を担う主要なモ−タ−タンパク質、アクチン分子とエネルギートランスデュ−サ−、ミオシン分子頭部の結晶構造が明らかにされて以来、筋収縮のメカニズム研究が一挙に原子レベルへと発展した。さらに2000年に入って筋収縮の制御を担うタンパク質トロポニン、トロポミオシンの結晶解析が進み、筋収縮における力の発生、制御メカニズムの研究が大きく進歩した。それらの発展には1980年代に本格化した第2世代のシンクロトロン放射光の利用によるＸ線回折が重要な役割を果たし、筋収縮メカニズムへの構造的基礎を提供してきた。さらに、今日第3世代の放射光が利用できるようになって単一筋細胞（single fiber、太さ100μm）を使っての研究が本格的に始まり、数十μsの時分割測定と数千nmの角度分解能を利用した新規な測定が可能になり、生理学により密着した研究が進められてきた。しかしながら、より正確な理解のためには、全筋（whole muscle）を使っての空間分解能の高いデータによるアクチン、ミオシン両フィラメントの構造解析が依然重要である。この立場による我々の筋収縮の分子メカニックスとアクチン、ミオシンフィラメントの原子レベルでの構造変化のＸ線研究を紹介し、細いアクチンフィラメントに注目した筋収縮の化学−力学エネルギ−変換の分子メカニズムを考察する。第１３回ＣＯＥセミナー（学科と共催）　NEW!! 　　　講師　S. G. Moiseenko（ロシア科学アカデミースペースリサーチインスティテュート）　　演題　Core collapse supernovae 　　日程　３月６日(木)　１６：３０－１８：００　　場所　55号館N棟第２階　物理・応物会議室　　紹介教員　山田章一アブストラクト： The explanation of the mechanism of core collapse supernovae is one of the most interesting and still not completely solved problems of modern astrophysics. We discuss current state of the core collapse supernovae problem and review different mechanisms of such supernovae. Numerical simulations of the bounce shock and neutrino driven supernova mechanisms either do not lead to the explosion or the explosion energy is too small. The Standing Accretion Shock Instability(SASI) mechanism also does not lead to the explosion in self-consistent simulations. In the talk we plan to review the results of our researches of MagnetoRotaional(MR) supernova mechanism in 2D approach. In MR supernova mechanism the rotational energy of the differentially rotating presupernova is partially transformed to the explosion energy by magnetic field. In 2D numerical simulations of the MR supernova. The evolution of the magnetic field leads to the development of the magnetorotational instability leading to the exponential growth both poloidal and toroidal magnetic fields. Our results of our simulations show that the supernova explosion corresponds to the observational data. The explosion energy depends on the initial core mass and initial rotational energy. 第１２回ＣＯＥセミナー　NEW!! 　　　講師　Seok-Cheol Hong（Assistant Professor in Department of Physics, Korea University）　　演題　Biophysical studies on structural changes of single DNA molecules 　　日程　２月２６日(火)　１５：００－１６：３０　　場所　55S号館 2階第四会議室　　紹介教員　石渡信一アブストラクト： Single molecule biophysical techniques have proven to be powerful approaches to illuminate physical principles behind a wide range of biological phenomena. Direct measurement of physical properties of individual biomolecules can reveal detailed dynamics by the molecule in real time without suffering from population averaging. In my talk, I will discuss our recent results of single-molecule investigations on structural changes in DNA. First, we report salt-dependent activity of cisplatin on DNA via micromanipulation of a single DNA molecule with magnetic tweezers. Upon binding to DNA, cisplatin, a potent mutagenic anti-cancer drug, was revealed to induce a dramatic change in the DNA persistence length in a strongly salt-dependent manner. At physiological salt concentration (~ 150 mM), cisplatin did not effectively bind to bare DNA. To understand this paradoxical behavior of the anti-cancer drug, we propose an alternative mechanism for the anti-cancer activity of cisplatin, in which a tiny amount of bound cisplatin may be sufficient to cause drastic modification in chromatin structure by irreversibly trapping histones. Second, we examined conformational transitions of a short palindromic AT-only region under tension and torsion. Under torsion, this sequence can readily form a bubble and in higher negative superhelicity, can take a cruciform structure. To investigate formation & dynamics of the cruciform structure in the short AT-only sequence at single molecule level, we developed a combined technique of single molecule FRET & magnetic tweezers, which enables us to observe conformational dynamics of a single DNA molecule in real time under tension and torsion, two important physical variables on DNA supercoiling & cruciform formation. In the AT-only palindromic sequence, we observed that even small negative twist induces bubble formation and that B-DNA, DNA bubble and cruciform coexist under proper tension and torsion. Furthermore, we revealed that the population of cruciform is changed by the tension because DNA buckling depends on pulling force. We confirmed that the cruciform initiation follows the S-type mechanism. 第１１回ＣＯＥセミナー　　　講師　Prof. Svetlana Strukova （モスクワ大学教授）　　演題　Proteinases of Haemostasis as cell regulators 　　日程　２月１２日(火)　１６：００－１７：３０　　場所　55号館N棟第２階　物理・応物会議室　　紹介教員　石渡信一アブストラクト： Serine proteinase thrombin via proteinase-activated receptors (PARs) is involved in regulation and control of blood coagulation, inflammation, tissue repair and neurodegenerative diseases. Concepts about the role of thrombin and other proteinase of blood coagulation system- APC ( Activated Protein C ), and their receptors (PARs, EPCR), which are expressed in CNS (Central Nervous System), gut and other systems during tissue injury, are very contradictory. There exists enough evidence for the deleterious or protective effects of thrombin via PARs in CNS and other systems, and the anti-inflammatory and anti-apoptotic effects of APC in endothelial cells and neurons (Henrich-Noack et al, 2006, Guo et al, 2004, Esmon, 2007, Steinhoff et al 2005, Strukova, 2006, Gorbacheva et al 2007). We hypothesize that the two events, the appearance of extremely low (pM-nM) concentrations of proteinase(s) in site of tissue/cell injury and coupling with PARs/coreceptors, which are expressed in this sites, are accounted for protective effects of these proteinase(s). In addition to other regulators (mediators, peptides, hormones, etc) the proteinases of haemostasis may be key modulators of cell survival and function at exitotoxicity. Taken together, our present data suggest that (1) APC may modulate neuron death at Glu-induced cytotoxicity via PAR1 (and/or EPCR?) activation, like very low thrombin concentrations, (2) APC via mast cell PAR1 can be involved in regulation of inflammatory processes and (3) APC can accelerate gastric ulcer healing in a rat model. Our data suggest a key role of APC in modulation of neuronal death and inflammation/tissue repair, but the precision mechanisms of APC protective effects on cells are yet unknown. 第１０回ＣＯＥセミナー　　　　講師　藤原郁子（米国　NIH/NHLBI研究員）　　演題　Direct observation of the uncapping of capped actin filaments by 　　　　　　CARMIL 　　日程　１２月２５日(火)　１６：００－１８：００　　場所　55号館S棟第４会議室　　紹介教員　石渡信一アブストラクト： Recent solution studies have shown that the ~80-residue CAH3 domain of CARMIL binds free Capping Protein (CP) with low nanomolar affinity, strongly inhibits the capping activity of CP, and rapidly and potently restores actin polymerization from actin filaments previously capped with CP. To investigate the mechanism of this uncapping activity directly, we observed individual capped actin filaments before and after the addition of the CAH3 domain of mouse CARMIL-1 (mCAH3) using TIRF microscopy. Real time observations showed that mCAH3 rescues the polymerization of capped filaments by driving the rapid dissociation of CP from the barbed end. The number of uncapped actin filaments was proportional to the concentration of mCAH3 added and saturated at ~250 nM mCAH3. The time interval between mCAH3 addition and uncapping decreased with increasing concentration of mCAH3, with the average half-life of CP at the barbed end decreasing from ~40 minutes without mCAH3 to ~10 seconds with saturating amounts of mCAH3. The actin polymerization rate itself was not altered at either the barbed or pointed ends by mCAH3. As anticipated from solution studies, mCAH3 containing a single point mutation (R993E) that blocks its binding to free CP was totally devoid of uncapping activity as measured by TIRF microscopy. We conclude that the isolated CAH3 domain of CARMIL, and presumably the intact molecule as well, possesses the ability to uncap capped actin filaments. This activity may drive, along with de novo nucleation and filament severing, the generation of free barbed ends in vivo, and may be responsible at least in part for the short half-life of CP at the barbed end inside cells (JCB, 2006). Our results contrast with a recent report that PIP2, which was also thought from previous solution studies to uncap capped filaments, does not do so when examined by TIRF microscopy (JBC, 2007). 第９回ＣＯＥセミナー　　　講師　Dr. Saxena (University of Cambridge) 　　演題　From quantum critical magnets to superconducting graphite 　　日程　１２月２５日(火)　１３：００－１６：００　　場所　55号館S棟第４会議室　　紹介教員　勝藤拓郎アブストラクト： This talk will discuss pressure induced superconductivity in the vicinity of magnetic quantum phase transitions. It will focus on how the search for magnetically mediated superconductivity in low dimensional systems led to new graphite superconductors. Low dimensionality is generally considered as a necessary ingredient for high superconducting transition temperatures. Surprisingly, perhaps, systems based on graphite have received little attention in this context. Introducing metal atoms between the carbon layers can tune the interlayer spacing and charging of the graphite host through a variety of electronic ground states. One such ground state is superconductivity, which is not present in pure graphite. Here we report the discovery of superconductivity in the intercalation compounds C6Yb and C6Ca, with transition temperatures of 6.5 and 11.5 K, respectively. These critical temperatures are unprecedented in graphitic systems and have not been explained exclusively by a simple phonon mechanism for the superconductivity. This discovery has already stimulated several proposals for the superconducting mechanism that range from coupling by way of the intercalant phonons through to acoustic plasmons. It also points towards the potential of superconductivity in other graphitic systems such as carbon nanotubes. 第８回ＣＯＥセミナー　　　講師　船引宏則（Rockefeller大、助教授）　　演題　Signals on and off chromosomes: mechanisms of 　　　　　　chromatin-induced phosphorylation during spindle assembly 　　　　　　and DNA damage-induced ubiquitylation 　　日程　１２月１９日(水)　１６：３０－１８：００　　場所　シルマンホール（66号館）10階会議室アブストラクト： Certain signals can be transmitted from chromosomes to their environment by transcription- and translation-independent mechanisms to control local and global molecular events. Using Xenopus egg extracts, we have been studying two such events important for maintaining genome integrity. During mitosis, chromosomes trigger molecular pathways that promote spindle microtubule assembly. Recently, we have demonstrated that the chromosomal protein kinase Aurora B is responsible for chromatin-induced phosphorylation, which locally inhibits microtubule-destabilizing proteins and contributes to chromatin-induced spindle assembly. We suggest that clustering and activation of Aurora B are coupled to spatially regulate this signaling pathway. Since Aurora B is localized between a pair of sister kinetochores and is a candidate for the protein that senses tension between sister kinetochores, the clustering-mediated activation mechanism may contribute to sense the tension between sister kinetochores. When DNA breaks are generated, specific proteins are recruited to the damage sites to repair the breaks and to delay cell cycle progression. However, it remains unclear how these proteins know the sites are repaired and dissociate from the repaired site. We show that poly-ubiquitination is specifically promoted by the DNA breaks, and that the Ku ring complex, which encircles DNA ends to promote DNA repair, is removed by ubiquitin-mediated proteolysis. We propose that topologically linked Ku at the repaired site would interfere with DNA replication fork progression and possibly other repair-related events, and thus the regulated degradation of Ku plays an important role during the DNA repair process. The mechanism by which Ku at the damage site is specifically ubiquitylated will be discussed. 第７回ＣＯＥセミナー　　講師　Prof. Christos Panagopoulos（University of Cambridge & IESL 　　　　　-FORTH）　　演題　Electronic complexity on the border of magnetism 　　日程　１２月１４日(金)　１３：００－１４：３０　　場所　55号館S棟2階　第3会議室　　紹介教員　勝藤拓郎アブストラクト： A variety of modern materials whose behaviour cannot be understood with traditional ideas have in common the dominant role played by electron-electron interaction effects. Examples of such systems are transition metal oxides, including high-temperature superconductors, heavy fermion metals, organic charge transfer compounds, and one-and two-dimensional electron gas systems. In the transition metal oxides for example, the charge, spin, and orbital degrees of freedom, and their coupled dynamics, produce complex phases such as liquid-like, crystal-like, and liquid-crystal-like states of electrons. Understanding and controlling the tendencies toward complexity will open the way to novel functionalities. In some cases, associated slow density fluctuations may even act in favour of superconductivity. The talk will address the physics and implications of electronic complexity in low dimensional systems with rich phase diagrams including insulating, metallic and superconducting ground states. 第６回ＣＯＥセミナー（北京大学デー特別講演）　　講師　Professor Shiyi Chen (College of Engineering, Peking University) 　　演題　Constrained variation in multiscale simulations of micro- and nano-　　　　　 fluidics and subgrid-scale stress model of fluid turbulence 　　日程　１１月１２日（月）　１３：３０－１５:００　　場所　55号館N棟2階　物理応物会議室アブストラクト：　 Finding physically consistent solutions in multiscale methods is crucial for various multiscale modeling and simulations. A framework for continuum and molecular dynamics hybrid multiscale method has been recently developed to simulate micro- and nano-fluid flows. In this approach, the continuum. Navier-Stokes equation is used in one flow region and atomistic molecular dynamics in another. The spatial coupling between two methods is achieved through the constrained dynamics in an overlap region. The proposed multiscale method has been validated in simple fluid flows, including sudden-start Couette flow and channel flow with nano-scale wall roughness, showing quantitative agreement with results from analytical solutions and full molecular dynamics simulations. The hybrid method is then used to study the singularity problems in the driven cavity and moving contact lines. Following the stress over more than six decades in length in systems with characteristic scales of millimeters and milliseconds allows us to resolve the singularity and determine the force for the first time. The speedup over pure atomistic calculation is more than fourteen orders of magnitudes. The similar idea of constrained variation has also been used for developing constrained dynamic subgrid-scale (C-SGS) stress model of fluid turbulence. In the C-SGS, we impose physical constraints in the dynamic procedure of calculating the SGS coefficients. In particular, we study dynamics mixed models with energy flux and helicity flux constraints. The comparison between the large eddy simulation results in steady and decay isotropic turbulence using constrained and non-constrained SGS models and those from direct numerical simulation (DNS) will be presented. It is found that the C-SGS not only predicts the turbulent dissipation more accurately, but also shows a strong correlation between the model stress and the real stress from a priori test, which is a desirable feature combing the advantages of dynamics Smagorinsky and traditional mixed models. 第５回ＣＯＥセミナー　　　講師　Prof. Sarah Rice (Cell and Molecular Biology, Northwestern univ.,USA) 　　演題　The Kinesin-1 Tail Regulates Motor Activity through an Interaction with Switch I 　　日程　９月２５日(火)　１６：００－１７:３０　　場所　 62号館W棟中会議室アブストラクト： In its regulated conformation, the kinesin-1 molecule folds such that the C-terminal tails are close to the heads and microtubule-stimulated ADP release is slowed significantly. Here we present the first direct evidence for a head-tail interaction. We cross-linked specific single cysteines on the kinesin head to random locations on the tail. Specific and efficient cross-links formed between a region very close to the conserved ⁹⁴¹QIAKPIRP₉₄₈ sequence of the tail and the a3/Switch I region of the head. We also performed cryo-electron microscopy on the head-tail cross-link bound to microtubules to confirm the interaction of the tail with a3/Switch 1. Other kinesin and/or myosin family members may have similar regulatory mechanisms. 第４回ＣＯＥセミナー　　　講師　Tae-Whan Kim 教授漢陽大学（韓国）　　演題　Formation and physical properties of hybrid nanomaterials for　　　　　　　　　　　　　applications in electronic and optical devices 　　日程　７月２４日（火）　１０：４０－　　場所　早稲田大学理工学部　51号館3階第二会議室　　紹介教員　竹内淳アブストラクト： TBA 第３回ＣＯＥセミナー　　　講師　小林航　氏（CRISMAT，フランス）　　演題　Thermoelectric properties of the misfit layered cobalt oxides and layered rhodium oxide　　　　　　　　　　　　　日程　６月１４日（木）　１６：００－１８：００　　場所　早稲田大学理工学部55号館N棟２階物理応物会議室　　紹介教員　寺崎一郎 ※なお講演は英語で行われます。アブストラクト： I would like to talk about my studies of thermoelectric oxides at CRISMAT laboratory in this seminar focusing on a relationship between transport properties and crystallography.　We have synthesized single-crystal samples of [Bi2A2O4-d][CoO2]p (A= Ca, Sr, and Ba, 1.65£p£2), [Bi1.6Pb0.6Sr2O4-d][CoO2]1.86, and Bi0.78Sr0.4RhO3+d by using flux method, and measured in-plane resistivity, thermopower and Hall coefficient. We found that the resistivity, the thermopower, and the Hall coefficient systematically decrease with increasing misfit ratio p and with Pb doping, which implies that carrier concentration increases with p and Pb doping. On the other hand, estimated power factors of these five samples converge to 2.2±0.3 microW/cmK2 at room temperature, which is not so trivial. Because variation of the carrier　concentration should cause variation of the power factor as seen in conventional thermoelectric semiconductors. Thus, not only carrier concentration but also another parameter such as effective mass and scattering time changes with p and Pb doping, which realizes the almost unique value of 2.2±0.3 microW/cmK2 at room temperature. ※詳細　第２回ＣＯＥセミナー　　　講師　Tassos Bountis （University of Patras）　　演題　Geometrical Properties of Local Dynamics in Hamiltonian systems: The Generalized Alignment Index (GALI) method 　　日程　４月１７日（火）１３：００－１４：３０　　場所　55号館Ｎ棟２階会議室　　紹介教員　相澤洋二アブストラクト： We investigate the dynamics of multidimensional Hamiltonian systems and symplectic maps, by studying volume elements formed by unit deviation vectors about their orbits. The different time evolution of these volumes is used to identify rapidly and efficiently the nature of the dynamics, leading to the introduction of quantities called the Generalized Alignment Index of order k (GALI_k). We show analytically and verify numerically on particular examples of N degree of freedom Hamiltonian systems that, for chaotic orbits, GALI_k tends exponentially to zero with exponents that depend on several Lyapunov exponents. In the case of regular orbits, GALI_k is nearly constant for N ³ k ³2 and goes to zero for 2N ³ k ³ N following power laws that depend on the dimension of the torus . We are thus able to: (i) detect chaotic oscillations of N—particle systems much faster than other methods, (ii) identify low--dimensional tori of Fermi--Pasta --Ulam lattices at low energies, (iii) identify 2- dimensional tori of quasiperiodic breathers in a lattice without linear dispersion and (iv) predict weak diffusion away from quasiperiodic motion in these lattices, long before it is actually observed in the oscillations. 2007年度　第１回ＣＯＥセミナー　　　講師　Tassos Bountis （University of Patras）　　演題　Simple Periodic, Lvapunov Spectra and the Themodynamic Limit in Hamiltonian Lattices 　　日程　４月６日（金）１３：００－１４：３０　　場所　 55号館Ｎ棟２階会議室　　紹介教員　相澤洋二アブストラクト： The connection between local and global stability of motion of N - degree of freedom Hamiltonian systems will be discussed, in an attempt to understand the properties of these systems when statistical mechanics is expected to take over from classical mechanics. I will focus on Simple Periodic Orbits (SPOs), i.e. periodic solutions with all degrees of freedom oscillating in phase (or out of phase) and with equal characteristic frequencies. In the case of the Fermi - Pasta - Ulam (FPU) lattice, I shall explain how the stability of these SPOs is related to the breakdown of FPU recurrences and discuss how the study of SPOs can shed light on the transition to large scale chaotic behavior characterized by invariant spectra of Lyapunov exponents. I shall concentrate on the relevance of these quantities to the case of N very large and in particular, in the thermodynamic limit, where both the energy E and N increase, with E/N = constant

ＣＯＥ談話会
	第２回ＣＯＥ談話会　　日時　９月２７日（木）１２：００－１２：４５　　場所　55号館Ｓ棟第三会議室　　講師　松田梓　物理学科教授　　題目　高温超伝導アブストラクト：はじめに高温超伝導の最近の研究の概略、到達点をごく簡単に紹介する。次に、擬ギャップ領域の特異性について、主にSTMを用いた研究を銅酸化物以外の酸化物のを交えて紹介する。第１回ＣＯＥ談話会　日時　６月２１日（木）１２：００－１２：４５　　場所　55号館Ｓ号館第三会議室　　講師　鵜飼一彦教授（応用物理学科）　　題目　視覚系情報処理機構の機能的解析アブストラクト：　　研究室で行われている研究は，大きく視覚のメカニズムの研究と動画像の生体影響に分けられる．今回は，前者（下記参照）につき，できるだけ多くの項目の目的と成果を簡単明瞭にお話しする．その過程で研究目的の選び方と手法の基本的考え方が伝われば幸いである．各項目の詳細については別の機会にお話ししたい．　●眼光学　・波面センサの開発　・調節測定装置の開発　●色と形　・色のついたcafé wall 錯視　・Neon Color Spreading と背景色　●奥行知覚　・ステレオスラント順応　・心理的手がかりと輻輳　●知覚交替　・加齢　・点滅による交替加速　・２種類の瞬目と知覚交替　●ベクション　・膨張／収縮運動：注意の位置・眼球運動・酔い　・回転運動：ベクションと物体運動の知覚交替　●眼球運動　・サッカードと視野安定　・カラーブレイクアップ　・輻輳眼球運動：中枢　・回旋眼球運動記録　・前庭動眼反射：運動種類による性格の差　●調節と輻輳：刺激矛盾時の調節　・輻輳性調節とぼけ刺激の綱引　・調節刺激の空間成分との関係　・輻輳性調節の個人差による動特性変化　●瞳孔　・膨張収縮運動刺激の運動変化時の認知的反応