• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.41-48
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• 2009

Natural magnetic fields are attenuated by electrically conductive water. For that reason, marine magnetotelluric surveys have collected data at long periods (1000-100 000 s). The mantle structure has been the main target of seafloor magnetotelluric measurements. To ascertain crustal structure, however, electromagnetic data at shorter periods are important, e.g. in investigations of megathrust earthquake zones, or in natural resource surveys. To investigate of the former, for example, electromagnetic data for periods of less than 1000 s are necessary. Because no suitable ocean bottom electromagnetometer (OBEM) has been available, we have developed a small OBEM and ocean bottom electrometer (OBE) system with a high sample rate, which has an arm-folding mechanism to facilitate assembly and recovering operations. For magnetic observation, we used a fluxgate sensor. Field observations were undertaken to evaluate the field performance of our instruments. All instruments were recovered and their electromagnetic data were obtained. Results of the first experiment show that our system functioned well throughout operations and observations. Results of other field experiments off Tottori support the claim that the electromagnetic data obtained using the new OBEM and OBE system are of sufficient quality for the survey target. These results suggest that this device removes all instrumental obstacles to measurement of electromagnetic fields on the seafloor.

• Journal of the Ergonomics Society of Korea
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• v.33 no.2
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• pp.109-124
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• 2014

Objective: This study was conducted for one-hand users including hemiplegic clients currently using general folding manual wheelchairs, so as to analyze their specific problems and recommend solutions regarding usage. Background: Traditional manual wheelchairs require considerable use and control of both hands for operation, thus adaptations become necessary for individuals with asymmetrical use of hands. Method: Thirty hemiplegic clients who were admitted to rehabilitation and convalescent hospitals participated as subjects. The research tools were general folding manual wheelchairs commonly used by people with impaired gait, and the Wheelchair Skills Tests (WST) WST-M/WCU 4.1 version was adopted as the assessment tool. All participants were asked to fill out questionnaires on demographics and wheelchair usage characteristics. Assessment procedures were performed with currently used manual wheelchairs and with/without the use of foot to control the wheelchair. Results: When the participants drove folding manual wheelchairs without the use of foot, even the lowest failure rate among the WST items tested recorded 96.7%. On the contrary, with the use of foot in maneuvering the wheelchairs, failure rates dropped noticeably and success rate among the WST items tested was as high as 86.7%. Conclusion: These findings imply that the use of one-arm (hand) propellable (drivable) wheelchair can be an active and effective solution in resolving problems for hemiplegic clients using existing manual wheelchairs. As such, the government should provide institutional support to further develop and distribute this device or technology, and promote relative research in tandem. For now, the supply of commercially available device to hemiplegic clients is deemed urgent and also a mechanism to provide the devices and relevant services. Application: This study offers viable solutions for hemiplegic clients who rely on existing manual wheelchairs to increase their mobility and occupational performance.

• Journal of the Korean Magnetic Resonance Society
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• v.12 no.1
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• pp.1-13
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• 2008

Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis: the synthesis of malonyl-CoA from acetyl-CoA. As essential regulators of fatty acid biosynthesis and metabolism, ACCs are regarded as therapeutic targets for the treatment of metabolic diseases such as obesity, In ACC, the biotinoyl domain performs a critical function by transferring an activated carboxyl group from the biotin carboxylase domain to the carboxyl transferase domain, followed by carboxyl transfer to malonyl-CoA. Despite the intensive research on this enzyme, only the bacterial and yeast ACC structures are currently available, To explore the mechanism of ACC holoenzyme function, we determined the structure of the biotinoyl domain of human ACC2 and analyze its characteristics using NMR spectroscopy. The 3D structure of the hACC2 biotinoyl domain has a similar folding topology to the previously determined domains from E. coli and P. Shermanii, however, the 'thumb' structure is absent in the hACC2 biotinoyl domain. Observations of the NMR signals upon the biotinylation indicate that the biotin group of hACC2 does not affect the structure of the biotinoyl domain, while the biotin group for E. coli ACC interacts directly with the thumb residues that are not present in the hACC2 structure. These results imply that, in the E. coli ACC reaction, the biotin moiety carrying the carboxyl group from BC to CT can pause at the thumb of the BCCP domain. The human biotinoyl domain, however, lacks the thumb structure and does not have additional non-covalent interactions with the biotin moiety; thus, the flexible motion of the biotinylated lysine residue must underlie the "swinging arm" motion. This study provides insight into the mechanism of ACC holoenzyme function and supports the "swinging arm" model in human ACCs.