The 116th KARC Colloquium
The 116th KARC Colloquium was ended. Thank you for the participation.
| Date&Time | 13 July 2012 (Fri) 13:30-17:20 |
| Place | Conference Room, 3F , Research Building 2, |
| Hosted by | SIG-MBI of JSAI and KARC Colloquium |
| Introduction 13:30-14:10 |
Konagaya Akihiko, Prof. of Tokyo Institute of Technology |
| Lecturer1 14:10-15:10 |
Large-scale vortex lattice emerging from collectively moving microtubules driven by axonemal dynein |
| Speaker | Oiwa Kazuhiro, Director General, Advanced ICT Research Institute, NICT |
| 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 hysics: 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. |
| Lecturer2 15:20-16:20 |
Topological Comparison of Brain Functional Networks and Internet Service Providers |
| Speaker | Leibnitz Kenji, Senior Researcher, Brain ICT Laboratory, Advanced ICT Research Institute, NICT |
| 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). |
| Lecturer3 16:20-17:20 |
Nobel methods for extraction of brain information from electroencephalogram |
| Speaker | Naruse Yasushi, Senior Researcher, Brain ICT Laboratory, Advanced ICT Research Institute, NICT |
| 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. |
| Language | English/Japanese |
| Admission | Free |
| Organizer | Hidefumi Sawai, Chief Senior Researcher, Planning Office, Advanced ICT Research Institute, NICT |