Mapping of the local environmental changes in proteins by cysteine scanning

Protein conformational changes, which regulate the activity of proteins, are induced by the alternation of intramolecular interactions. Therefore, the detection of the local environmental changes around the key amino acid residues is essential to understand the activation mechanisms of functional proteins. Here we developed the methods to scan the local environmental changes using the vibrational band of cysteine S-H group. We validated the sensitivity of this method using bathorhodopsin, a photoproduct of rhodopsin trapped at liquid nitrogen temperature, which undergoes little conformational changes from the dark state as shown by the X-ray crystallography. The cysteine residues were individually introduced into 15 positions of Helix III, which contains several key amino acid residues for the light-induced conformational changes of rhodopsin. The shifts of S-H stretching modes of these cysteine residues and native cysteine residues upon the formation of bathorhodopsin were measured by Fourier transform infrared spectroscopy. While most of cysteine residues demonstrated no shift of S-H stretching mode, cysteine residues introduced at positions 117, 118, and 122, which are in the vicinity of the chromophore, demonstrated the significant changes. The current results are consistent with the crystal structure of bathorhodopsin, implying that the cysteine scanning is sensitive enough to detect the tiny conformational changes

The Development of an Interaction Analysis Support System for asynchronous CSCL

近年、初等中等教育や高等教育における協調学習の重要性がますます指摘されるようになっている。また、学校へのインターネット接続が急速に進み、CSCL(Computer Supported Collaborative Learning)に関する研究が多く行われ、実践でも掲示板等を使ったWeb上での協調学習が多く見られる。しかし、授業実践者が学習者の学習過程を分析する際、対話の履歴が保存されることは大きな利点となるが、学習者の知識構造が変化する過程といった質的な分析は授業実践者が対話の内容を一つ一つチェックして行うしかなく、この困難さが掲示板によるCSCL実践のネックの一つであると言える。そこで本研究では、授業実践者が蓄積された対話のデータをいくつかの観点からカテゴライズすることによって、協調学習を量的・質的に分析するのを支援するシステムの開発を行う。Recently, the importance of collaborative learning in school education is coming to be recognized more. And, internet connectivity to each school is proceeding rapidly. By these reasons, much research about CSCL (Computer Support Collaborative Learning) and much collaborative learning on the Web bulletin board in school education are being done. But, a teacher must check each content of the learner's dialogue in detail to analyze learning process in CSCL. This difficutty is one of the bottlenecks of the CSCL using the bulletin board. So, in this research, we develop a support system that supports a teacher to analyze collaborative learning by categorizing the dialog data based on some viewpoints

5.Technology

熊本大学Nihonrimonaito, CoHujikinzoku CoEditor : Tazaki, Kazue, Cover:Scanning electoron microscopic photograph of Gallionella sp. in biomats of Aso caldera, Kyusyu, Japan. Various shapes of Gallonella sp. are shown (image:Moriichi, Shingo).COE, 金沢大学 水・土壌環境領域シンポジウム「地球環境における微生物の役割」, 日時：2002年12月4日（水）13：00～, 場所：金沢大学理学部3階第一実験

Spicule Dynamics over Plage Region

We studied spicular jets over a plage area and derived their dynamic characteristics using Hinode Solar Optical Telescope (SOT) high-resolution images. The target plage region was near the west limb of the solar disk. This location permitted us to study the dynamics of spicular jets without the overlapping effect of spicular structures along the line of sight. In this work, to increase the ease with which we can identify spicules on the disk, we applied the image processing method `MadMax' developed by Koutchmy et al. (1989). It enhances fine, slender structures (like jets), over a diffuse background. We identified 169 spicules over the target plage. This sample permits us to derive statistically reliable results regarding spicular dynamics. The properties of plage spicules can be summarized as follows: (1) In a plage area, we clearly identified spicular jet features. (2) They were shorter in length than the quiet region limb spicules, and followed ballistic motion under constant deceleration. (3) The majority (80%) of the plage spicules showed the cycle of rise and retreat, while 10% of them faded out without a complete retreat phase. (4) The deceleration of the spicule was proportional to the velocity of ejection (i.e. the initial velocity).Comment: 12 pages, 9 figures, accepted for publication in PAS