- 著者
- Kimiko YAMAKAWA-KOBAYASHI Yuya OHHARA Takumi KAWASHIMA Yoshitatsu OHISHI Yasunari KAYASHIMA
- 出版者
- Biomedical Research Press
- 雑誌
- Biomedical Research (ISSN:03886107)
- 巻号頁・発行日
- vol.41, no.3, pp.131-138, 2020-06-01 (Released:2020-06-11)
- 参考文献数
- 40
- 被引用文献数
- 2
Increasing oxidative stress seems to be the result of an imbalance between free radical production and antioxidant defenses. During the course of aging, oxidative stress causes tissue/cellular damage, which is implicated in numerous age-related diseases. Carnosinase (CN or CNDP) is dipeptidase, which is associated with carnosine and/or glutathione (GSH) metabolism, those are the most abundant naturally occurring endogenous dipeptide and tripeptides with antioxidant and free radical scavenger properties. In the present study, we generated Drosophila cndp (dcndp) mutant flies using the CRISPR/Cas9 system to study the roles of dcndp in vivo. We demonstrate that dcndp mutant flies exhibit shorter lifespan and increased sensitivity to paraquat or hydrogen peroxide (H2O2) induced oxidative stress. These results suggest that dcndp maintains homeostatic conditions, protecting cells and tissues against the harmful effects of oxidative stress in the course of aging.
- 著者
- Shigeaki Amano Hideki Kawahara Hideki Banno Katuhiro Maki Kimiko Yamakawa
- 出版者
- ACOUSTICAL SOCIETY OF JAPAN
- 雑誌
- Acoustical Science and Technology (ISSN:13463969)
- 巻号頁・発行日
- vol.43, no.2, pp.105-112, 2022-03-01 (Released:2022-03-01)
- 参考文献数
- 30
A perception experiment and analyses were conducted to clarify the acoustic features of pop-out voice. Speech items pronounced by 779 native Japanese speakers were prepared for stimuli by mixing them with a babble noise that consisted of overlapping short sentences spoken by 10 Japanese speakers. Using a 5-point scale, 12 Japanese participants rated the pop-out score of the speech items listened using headphones. The scores and acoustic features of the speech items were investigated using correlation analysis and principal coordinate analysis. It was revealed that the pop-out score relates to the acoustic features such as overall intensity, relative intensity in the high-frequency range, fundamental frequency, dynamic feature of the spectrum, and a spectrum shape in high frequency. The results suggest that these are crucial acoustic features for the pop-out voice.
- 著者
- Kimiko Yamakawa Shigeaki Amano Mariko Kondo
- 出版者
- ACOUSTICAL SOCIETY OF JAPAN
- 雑誌
- Acoustical Science and Technology (ISSN:13463969)
- 巻号頁・発行日
- vol.43, no.5, pp.241-250, 2022-09-01 (Released:2022-09-01)
- 参考文献数
- 27
Vietnamese speakers' mispronunciations of Japanese singleton and geminate stops were identified using the category boundary of the stops pronounced by native Japanese speakers. To clarify the characteristics of the Vietnamese speakers' mispronunciations, their speech segment durations were analyzed. In comparison with native Japanese speakers' correct pronunciations, Vietnamese speakers mispronounced a singleton stop with a longer closure and a shorter preceding consonant-vowel segment, whereas they mispronounced a geminate stop with a shorter closure and a longer following consonant-vowel segment. These results were consistent with the findings of Korean, Taiwanese Mandarin, and Thai speakers in previous studies, suggesting that non-native speakers may have a common tendency to have inadequate durations of closure and anteroposterior consonant-vowel segments in mispronunciations of Japanese singleton and geminate stops.
- 著者
- Yasunari KAYASHIMA Keiko YAMANASHI Ayaka SATO Shigenori KUMAZAWA Kimiko YAMAKAWA-KOBAYASHI
- 出版者
- (社)日本農芸化学会
- 雑誌
- Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
- 巻号頁・発行日
- pp.120496, (Released:2012-11-07)
- 被引用文献数
- 19 10
Royal jelly (RJ), a honeybee-derived product, has been found to possess developmental and physiological bioactivity in the fruit fly, Drosophila melanogaster, but little is known about the in vivo bioactivity of freeze-dried RJ (FDRJ) powder, which is another form of RJ processed for human use. To address this, we used Drosophila as a model animal to examine the effects of FDRJ in multicellular organisms. When flies were reared on food supplemented with FDRJ, the developmental time from larva to adult was shortened, the adult male lifespan was prolonged, and female fecundity was increased without any significant morphological alterations. Moreover, the expression of dilp5, an insulin-like peptide, its receptor InR, and the nutrient sensing molecule TOR, the target of rapamycin, was significantly increased in FDRJ-fed female flies as compared with ones reared on standard and on protein-enriched food. These findings suggest that like RJ, FDRJ maintains its bioactivity even after processing from RJ, what is expected to have bioactivity for multicellular organisms, including humans.