第49回 人工知能学会 分子生物情報研究会 (SIG-MBI)

日時:2012年7月13日(金) 午後1:30―5:20
場所:情報通信研究機構(NICT) 未来ICT研究所(神戸)
第2研究棟3F 中会議室(アクセス)
主催:SIG-MBIとKARCコロキウムとの共催

スケジュール:
PM
1:30−2:10 研究会の趣旨説明 小長谷主査

2:10−3:10 Presentation 1
Oiwa Kazuhiro, Director General 大岩 和弘 所長

Title: Large-scale vortex lattice emerging from collectively moving
microtubules driven by axonemal dynein.
(軸糸ダイニンによる微小管滑り運動が創発する巨大な渦構造)

Abstract: The physics of active matter is a new emerging field dealing with
systems where energy is spent locally to produce persistent, directed
motion. Numerous situations are concerned, at all scales, in natural and
in man-made systems, from the collective displacement of large groups of
animals, swarms of robots without central control, bacteria and amoeba
colonies, cells in organs, down to the subcellular level where molecular
motors, transforming chemical energy into mechanical work, are in charge
of many transport processes and of the general, large-scale integrity of
the cell. It is in this last context that well-controlled in vitro
experiments on active matter are nowadays possible: purified biological
components extracted from living cells, are mixed in well-defined
conditions, giving rise to large-scale, self-organized, cooperative
phenomena, which can be observed, via fluorescent marking, under the
microscope.
We performed the in vitro motility assays consisted in putting
microtubules in contact with a high-density carpet of axonemal dynein
molecules grafted to a substrate. In presence of ATP, the dynein heads
attach to the microtubules and cooperatively move them around in a
smooth, steady, two-dimensional motion. In a few minutes, a lattice of
vortices spontaneously appear, which have a very large diameter (about
400 um) compared to the microtubule's length (about 10 um) and size of a
dynein molecule (about 50 nm).
The analysis of further experiments performed on isolated filaments and
the construction of a semi-quantitative mathematical model have allowed
to show that only two basic ingredients are at the origin of the
organized collective motion of millions of filaments forming the vortex
lattice: the smooth, reptation-like motion of isolated microtubules and
their physical collisions leading to nematic alignment.
This set of results constitutes a breakthrough in the field since it has
allowed to show clearly, on a real case, what often remains a belief,
albeit a well-grounded one, in theoretical statistical physics: a
minimal set of simple mechanisms is sufficient to account quantitatively
for complex emergent phenomena. Beyond this intellectual satisfaction,
these results have also an important potential relevance in biology, in
particular for understanding the formation of the plant cell cortex.
More generally, they could be exploited in the quest for novel biomaterials.

Break(10 min.)

3:20−4:20 Presentation 2
Leibnitz Kenji Senior Researcher, ライプニッツ・ケンジ 主任研究員

Title: Topological Comparison of Brain Functional Networks and Internet
Service Providers

Abstract: Network structures can be found in almost any kind of natural
or artificial systems as transport medium for communication between the
respective nodes. In this talk we study topological features of brain
functional networks and discuss similarities and differences of their
network measures to those of Internet service providers (ISPs).

4:20−5:20 Presentation 3
Naruse Yasushi Senior Researcher, 成瀬 康 主任研究員

Title: Nobel methods for extraction of brain information from
electroencephalogram.
(脳情報を脳波から抽出する技術の開発)

Abstract: Brain information communication technology (Brain ICT) is a
futuristic technology that aims to achieve freer, smoother
communications by extracting information from the brain and transmitting
it. To develop brain ICT, the first thing we need is a technology for
extracting brain information with high accuracy. We succeeded in
development of novel methods for extracting brain information that
relate to non-linear phenomena in the brain from single trials
electroencephalographic data.

脳情報通信技術というのは脳から情報をとりだし,それを通信することにより,
ブレインマシンインターフェースといったシステムを実現するための技術であ
る.脳情報通信技術の実現の為に,まず,はじめに確立するべき技術は,重要な
脳情報を脳から取り出す技術である.我々は脳内処理の過程で起こっていると思
われる非線形現象に伴う脳情報を単一試行脳波から取り出す技術の開発に成功した.

5:20− Closing