Kyushu University · Materials Science
Professor Koji Takahashi's research lab specializes in molecular phylogenetics, focusing on the evolutionary significance of short interspersed repetitive elements (SINEs) in vertebrate speciation, particularly in adaptive radiations such as cichlid fish in Lake Tanganyika. The lab also conducts interdisciplinary research in bio-signals and emotion recognition, leveraging multi-modal physiological data and machine learning techniques like SVM for affective computing. Additionally, the lab explores nanoscale materials and fluid behavior, investigating epitaxial crystal growth on silicon substrates and the unique properties of water confined in carbon nanotubes. These diverse research directions reflect a strong integration of molecular biology, biomedical engineering, and nanomaterials science.
Figures are computed from collected data and may differ slightly.
Short interspersed repetitive elements (SINEs) have been shown to be excellent markers of molecular phylogeny, since the integration of a SINE at a particular position in a genome can be considered an unambiguous derived homologous character. In the present study, we isolated a new family of SINEs from cichlids in Lake Tanganyika, whose speciation and diversification have been regarded as prime examples of explosive adaptive radiation. Members of this new SINE family, which we named the AFC fami
This paper proposes an emotion recognition system from multi-modal bio-potential signals. For emotion recognition, support vector machines (SVM) are applied to design the emotion classifier and its characteristics are investigated. Using gathered data under psychological emotion stimulation experiments, the classifier is trained and tested. In experiments of recognizing five emotion: joy, anger, sadness, fear, and relax, recognition rate of 41.7% is achieved. The experimental result shows that u
This work proposes an emotion recognition system from multi-modal bio-potential signals. For emotion recognition, support vector machines (SVM) are applied to design the emotion classifier and its characteristics are investigated. Using gathered data under psychological emotion stimulation experiments, the classifier is trained and tested. In experiments of recognizing five emotion: joy, anger, sadness, happiness, and relax, recognition rate of 41.1% is achieved. The experimental result shows th
Crystal growth of on Si(100), (111) substrate was carried out by atmospheric pressure chemical vapor deposition using hexamethyldisilane and gas mixtures. Temperature dependence of growth rate and crystallinity of films were examined. The growth process was characterized by a mass spectrometric study of the decomposition of HMDS and mixtures. Using HMDS as a source material, low temperature epitaxy was realized at a substrate temperature of 1100°C. With and without a carbonized buffer layer, sin
Fluids confined in a nanoscale space behave differently than in the bulk due to strong interactions between fluid molecules and solid atoms. Here, we observed water confined inside "open" hydrophilized carbon nanotubes (CNT), with diameter of tens of nanometers, using transmission electron microscopy (TEM). A 1–7 nm water film adhering to most of the inner wall surface was observed and remained stable in the high vacuum (order of 10–5 Pa) of the TEM. The superstability of this film was attribute
This paper proposes an algorithm for detecting bicycles on the road from a sequence of images acquired by a stationary video camera. This algorithm is suitable for monitoring the traffic situation for safety, our algorithm includes shape-based object detection using HOG and SVM and relative motion detection for leg movements in bicycle pedaling. The leg movement, which can be achieved by using spatiotemporal 3D Gabor filtering, can discriminate bicycles from similar objects such as motorbikes.
The adaptive response is a cellular process to induce DNA repair enzymes in response to a challenge of alkylating agents. In this process Ada protein, the product of the ada gene, plays a major role; it accepts the methyl groups of the methylated DNA at the cysteine residues of its own molecule, and the methylated form of Ada protein promotes transcription of its own gene, thereby triggering induction of the whole process. In addition to this DNA-mediated activation of Ada protein, we have propo
Water confined in carbon nanotubes (CNTs) can exhibit distinctly different behaviors from the bulk. We report transmission electron microscopy (TEM) observation of water phases inside hydrophobic cup-stacked CNTs exposed to high vacuum. Unexpectedly, we observed stable water morphologies beyond surface-tension dominance, including nanometer thin free water films, complex water-bubble structures, and zigzag-shaped liquid-gas interface. The menisci of the water phases are complex and inflected, wh
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