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418 results on '"Yamashita, Takahiro"'

1. Enforce and selective operators of combinatorial games

Author

Abuku, Tomoaki, Kimura, Shun-ichi, Kiya, Hironori, Larsson, Urban, Saha, Indrajit, Suetsugu, Koki, and Yamashita, Takahiro

Subjects
Mathematics - Combinatorics
Abstract

We consider an {\em enforce operator} on impartial rulesets similar to the Muller Twist and the comply/constrain operator of Smith and St\u anic\u a, 2002. Applied to the rulesets A and B, on each turn the opponent enforces one of the rulesets and the current player complies, by playing a move in that ruleset. If the outcome table of the enforce variation of A and B is the same as the outcome table of A, then we say that A dominates B. We find necessary and sufficient conditions for this relation. Additionally, we define a {\em selective operator} and explore a distributive-lattice-like structure within applicable rulesets. Lastly, we define nim-values under enforce-rulesets, and establish that the Sprague-Grundy theory continues to hold, along with illustrative examples., Comment: 25 pages, 12 figures, 1 table

Published
2023

2. On variations of Yama Nim and Triangular Nim

Author

Kimura, Shun-ichi and Yamashita, Takahiro

Subjects
Mathematics - Combinatorics, 91A46
Abstract

Yama Nim is a two heaps Nim game introduced in the second author's Master Thesis, where the player takes more than $2$ tokens from one heap, and return $1$ token to the other heap. Triangular Nim is a generalization, where the player takes several tokens from one heap, and return some tokens (at least one token) to the other heap, so that the total number of the tokens in the heaps decrease strictly. In this paper, we investigate their winning strategies, Grundy numbers, and their variations and generalizations. Particularly interesting is the Wythoff variations, where in addition to the Yama/Triangular Nim moves, the player is allowed to take tokens from both heaps, say $i$ tokens from the first heap and $j$ tokens from the other, under some restrictions for $i$ and $j$. For example when we force $i=j>0$ for the Triangular Nim, then the pair of non-negative integers $(x, y)$ with $x$ less than or equal to $y$ is in the $P$-position if and only if $(x, y) is in {(0, 0), (0, 1), (1, 3), (3, 6), (6, 10), (10, 15), ...}$, namely the winning strategy is described by triangular numbers. In other rulesets, we also found examples where the square numbers, pentagonal numbers, geometric progressions, and so on., Comment: 20 pages

Published
2023

8. Rhodopsin-mediated light-off-induced protein kinase A activation in mouse rod photoreceptor cells

Author

Sato, Shinya, Yamashita, Takahiro, and Matsuda, Michiyuki

Subjects
Biological Psychology, Biomedical and Clinical Sciences, Psychology, Neurosciences, Eye Disease and Disorders of Vision, Neurodegenerative, Aetiology, 2.1 Biological and endogenous factors, Animals, Cyclic AMP-Dependent Protein Kinases, Dopamine, Enzyme Activation, Mice, Transgenic, Microscopy, Fluorescence, Multiphoton, Retinal Rod Photoreceptor Cells, Rhodopsin, Transducin, retina, two-photon microscopy, FRET biosensor, protein kinase A, rhodopsin
Abstract

Light-induced extrasynaptic dopamine release in the retina reduces adenosine 3',5'-cyclic monophosphate (cAMP) in rod photoreceptor cells, which is thought to mediate light-dependent desensitization. However, the fine time course of the cAMP dynamics in rods remains elusive due to technical difficulty. Here, we visualized the spatiotemporal regulation of cAMP-dependent protein kinase (PKA) in mouse rods by two-photon live imaging of retinal explants of PKAchu mice, which express a fluorescent biosensor for PKA. Unexpectedly, in addition to the light-on-induced suppression, we observed prominent light-off-induced PKA activation. This activation required photopic light intensity and was confined to the illuminated rods. The estimated maximum spectral sensitivity of 489 nm and loss of the light-off-induced PKA activation in rod-transducin-knockout retinas strongly suggest the involvement of rhodopsin. In support of this notion, rhodopsin-deficient retinal explants showed only the light-on-induced PKA suppression. Taken together, these results suggest that, upon photopic light stimulation, rhodopsin and dopamine signals are integrated to shape the light-off-induced cAMP production and following PKA activation. This may support the dark adaptation of rods.

Published
2020

12. Dark noise and retinal degeneration from D190N-rhodopsin

Author

Silverman, Daniel, Chai, Zuying, Yue, Wendy W. S., Ramisetty, Sravani Keerthi, Lokappa, Sowmya Bekshe, Sakai, Kazumi, Frederiksen, Rikard, Bina, Parinaz, Tsang, Stephen H., Yamashita, Takahiro, Chen, Jeannie, and Yau, King-Wai

Published
2020

16. Validity of a Web-Based 24-Hour Dietary Recall of Energy and Nutrient Intakes in Japanese Adults.

Author

Nakadate, Misako, Kobayashi, Shunichiro, Ishihara, Junko, Takachi, Ribeka, Sugawara, Shiori, Hoshina, Yuchie, Kito, Kumiko, Kotemori, Ayaka, Maruya, Sachiko, Suzuki, Aoi, Obara, Taku, Ishikuro, Mami, Ueno, Fumihiko, Noda, Aoi, Aizawa, Misato, Takahashi, Ippei, Yonezawa, Yudai, Yamashita, Takahiro, Suzuki, Shigenori, and Murakami, Keiko

Abstract

Recently, web-based dietary assessment tools for the targeted population have been developed and used to estimate the dietary intake level in several epidemiological studies. This study aimed to examine the validity of estimating energy and nutrient intake by the web-based 24 h dietary recall (Web24HR), which we developed for the Japanese population. Overall, 228 adults aged ≥20 years who agreed to participate were included. Web24HR was administered three times per person: twice within 3 weeks and once 3 months later. The data on 3-day weighed food records (WFR) at 3-month intervals in the four seasons were collected using the reference method. The intake of energy and nutrients between Web24HR and WFR were compared using Pearson's correlation coefficients and the Bland–Altman analysis. As results, the correlations were moderate for both men (median r = 0.51) and women (median r = 0.38) except for iodine, retinol, retinol equivalents, and β-tocopherol. The Bland–Altman method revealed that the bias in intake was within ±10% for most nutrients, except for cholesterol, iodine, vitamin C, and the water content, in both sexes. Additionally, monounsaturated fatty acids in men and β-cryptoxanthin in women exhibited an underestimation of more than 10%. In conclusion, the Web24HR intake assessment showed moderate correlations for most nutrients in both sexes. The bias in intake was within ±10% for most nutrients, but there were discrepancies for some nutrients. This tool's performance is comparable to Japan's standard dietary exposure assessment methods and will be helpful for future applications in epidemiological studies, though caution is needed for certain nutrient assessments. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Functional diversification process of opsin genes for teleost visual and pineal photoreceptions

Author

50378535, Fujiyabu, Chihiro, Gyoja, Fuki, Sato, Keita, Kawano-Yamashita, Emi, Ohuchi, Hideyo, Kusakabe, Takehiro G., Yamashita, Takahiro, 50378535, Fujiyabu, Chihiro, Gyoja, Fuki, Sato, Keita, Kawano-Yamashita, Emi, Ohuchi, Hideyo, Kusakabe, Takehiro G., and Yamashita, Takahiro

Abstract

Most vertebrates have a rhodopsin gene with a five-exon structure for visual photoreception. By contrast, teleost fishes have an intron-less rhodopsin gene for visual photoreception and an intron-containing rhodopsin (exo-rhodopsin) gene for pineal photoreception. Here, our analysis of non-teleost and teleost fishes in various lineages of the Actinopterygii reveals that retroduplication after branching of the Polypteriformes produced the intron-less rhodopsin gene for visual photoreception, which converted the parental intron-containing rhodopsin gene into a pineal opsin in the common ancestor of the Teleostei. Additional analysis of a pineal opsin, pinopsin, shows that the pinopsin gene functions as a green-sensitive opsin together with the intron-containing rhodopsin gene for pineal photoreception in tarpon as an evolutionary intermediate state but is missing in other teleost fishes, probably because of the redundancy with the intron-containing rhodopsin gene. We propose an evolutionary scenario where unique retroduplication caused a “domino effect” on the functional diversification of teleost visual and pineal opsin genes.

Published
2024

26. Impact of Excessive Increase in Systolic Blood Pressure after Exercise on Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction

Author

Yamashita, Takahiro, primary, Sakakura, Kenichi, additional, Jinnouchi, Hiroyuki, additional, Taniguchi, Yousuke, additional, Tsukui, Takunori, additional, Hatori, Masashi, additional, Tamanaha, Yusuke, additional, Kasahara, Taku, additional, Watanabe, Yusuke, additional, Yamamoto, Kei, additional, Seguchi, Masaru, additional, and Fujita, Hideo, additional

Published
2023
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29. Serum brain natriuretic peptide levels may be a useful marker for early diagnosis of cardiomyopathy secondary to neuroblastoma: A case report.

Author

Fujiyama, Natsumi, Matsuo, Osamu, Yamashita, Takahiro, Kohrogi, Kensaku, Miyamura, Fumiya, Anan, Tadashi, and Nakamura, Kimitoshi

Subjects
BRAIN natriuretic factor, CARDIOMYOPATHIES, NEUROBLASTOMA, HEART failure, EARLY diagnosis, DILATED cardiomyopathy
Abstract

Key Clinical Message: Cardiomyopathy is a rare but serious complication associated with neuroblastoma. The brain natriuretic peptide level led to a diagnosis of secondary dilated cardiomyopathy before the worsening of heart failure symptoms. [ABSTRACT FROM AUTHOR]

Published
2024
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34. Diversification processes of teleost intron-less opsin genes

Author

50378535, Fujiyabu, Chihiro, Sato, Keita, Ohuchi, Hideyo, Yamashita, Takahiro, 50378535, Fujiyabu, Chihiro, Sato, Keita, Ohuchi, Hideyo, and Yamashita, Takahiro

Abstract

Opsins are universal photosensitive proteins in animals. Vertebrates have a variety of opsin genes for visual and non-visual photoreceptions. Analysis of the gene structures shows that most opsin genes have introns in their coding regions. However, teleosts exceptionally have several intron-less opsin genes which are presumed to have been duplicated by an RNA-based gene duplication mechanism, retroduplication. Among these retrogenes, we focused on the Opn4 (melanopsin) gene responsible for non-image-forming photoreception. Many teleosts have five Opn4 genes including one intron-less gene, which is speculated to have been formed from a parental intron-containing gene in the Actinopterygii. In this study, to reveal the evolutionary history of Opn4 genes, we analyzed them in teleost (zebrafish and medaka) and non-teleost (bichir, sturgeon and gar) fishes. Our synteny analysis suggests that the intron-less Opn4 gene emerged by retroduplication after branching of the bichir lineage. In addition, our biochemical and histochemical analyses showed that, in the teleost lineage, the newly acquired intron-less Opn4 gene became abundantly used without substantial changes of the molecular properties of the Opn4 protein. This stepwise evolutionary model of Opn4 genes is quite similar to that of rhodopsin genes in the Actinopterygii. The unique acquisition of rhodopsin and Opn4 retrogenes would have contributed to the diversification of the opsin gene repertoires in the Actinopterygii and the adaptation of teleosts to various aquatic environments.

Published
2023

35. miR-34a-5p might have an important role for inducing apoptosis by down-regulation of SNAI1 in apigenin-treated lung cancer cells

Author

Aida, Rieko, Hagiwara, Keitaro, Okano, Kazunori, Nakata, Kyoko, Obata, Yuho, Yamashita, Takahiro, Yoshida, Kaoru, Hagiwara, Hiromi, Aida, Rieko, Hagiwara, Keitaro, Okano, Kazunori, Nakata, Kyoko, Obata, Yuho, Yamashita, Takahiro, Yoshida, Kaoru, and Hagiwara, Hiromi

Abstract

Apigenin is a flavonoid with antioxidant and anticancer effects. It has been reported that apigenin inhibits proliferation, migration, and invasion and induces apoptosis in cultured lung cancer cells. However, there is little information on the involvement of microRNAs (miRNAs) in its effects. miRNA microarray analysis and polymerase-chain-reaction analysis of miRNAs revealed that treatment of human lung cancer A549 cells with apigenin up-regulated the level of miR-34a-5p. Furthermore, mRNA microarray analysis and the results of three microRNA target prediction tools showed that Snail Family Transcriptional Repressor 1 (SNAI1), which inhibits the induction of apoptosis, had its mRNA expression down-regulated in A549 cells treated with apigenin. Our findings suggest that apigenin might induce apoptosis by down-regulation of SNAI1 through up-regulation of miR-34a-5p in A549 cells.

Published
2023

36. Chromophore Structure in an Inactive State of a Novel Photosensor Protein Opn5L1: Resonance Raman Evidence for the Formation of a Deprotonated Adduct at the 11th Carbon Atom

Author

1000010464257, Mizuno, Misao, 1000080725622, Sato, Keita, 1000050378535, Yamashita, Takahiro, Sakai, Kazumi, 1000080263200, Imamoto, Yasushi, 1000050208831, Yamano, Yumiko, 1000080158683, Wada, Akimori, 1000000253229, Ohuchi, Hideyo, 1000060127090, Shichida, Yoshinori, 1000060270469, 0000-0002-3754-5720, Mizutani, Yasuhisa, 1000010464257, Mizuno, Misao, 1000080725622, Sato, Keita, 1000050378535, Yamashita, Takahiro, Sakai, Kazumi, 1000080263200, Imamoto, Yasushi, 1000050208831, Yamano, Yumiko, 1000080158683, Wada, Akimori, 1000000253229, Ohuchi, Hideyo, 1000060127090, Shichida, Yoshinori, 1000060270469, 0000-0002-3754-5720, and Mizutani, Yasuhisa

Abstract

Misao Mizuno, Keita Sato, Takahiro Yamashita, Kazumi Sakai, Yasushi Imamoto, Yumiko Yamano, Akimori Wada, Hideyo Ohuchi, Yoshinori Shichida, and Yasuhisa Mizutani, Chromophore Structure in an Inactive State of a Novel Photosensor Protein Opn5L1: Resonance Raman Evidence for the Formation of a Deprotonated Adduct at the 11th Carbon Atom, The Journal of Physical Chemistry B, 127(10), 2169-2176, March 16, 2023, © 2023 American Chemical Society. DOI: 10.1021/acs.jpcb.2c08780, Opsins are photosensitive G protein-coupled receptor proteins and are classified into visual and nonvisual receptors. Opn5L1 is a nonvisual opsin that binds all-trans retinal as a chromophore. A unique feature of Opn5L1 is that the protein exhibits a photocyclic reaction upon photoexcitation. Determining the chromophore structures of intermediates in the photocycle is essential for understanding the functional mechanism of Opn5L1. A previous study revealed that a long-lived intermediate in the photocycle cannot activate the G protein and forms a covalent bond between the retinal chromophore and a nearby cysteine residue. However, the position of this covalent bond in the chromophore remains undetermined. Here, we report a resonance Raman study on isotopically labeled samples in combination with density functional theory calculations and reveal that the 11th carbon atom of the chromophore of the intermediate forms a covalent linkage to the cysteine residue. Furthermore, vibrational assignments based on the isotopic substitutions and density functional theory calculations suggested that the Schiff base of the intermediate is deprotonated. The chromophore structure determined in the present study well explains the mechanism of the photocyclic reaction, which is crucial to the photobiological function of Opn5L1.

Published
2023

37. Chromophore Structure in an Inactive State of a Novel Photosensor Protein Opn5L1: Resonance Raman Evidence for the Formation of a Deprotonated Adduct at the 11th Carbon Atom

Author

Mizuno, Misao, primary, Sato, Keita, additional, Yamashita, Takahiro, additional, Sakai, Kazumi, additional, Imamoto, Yasushi, additional, Yamano, Yumiko, additional, Wada, Akimori, additional, Ohuchi, Hideyo, additional, Shichida, Yoshinori, additional, and Mizutani, Yasuhisa, additional

Published
2023
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38. Association of Plasma Lipopolysaccharide-Binding Protein Concentration with Dietary Factors, Gut Microbiota, and Health Status in the Japanese General Adult Population: A Cross-Sectional Study

Author

Fuke, Nobuo, primary, Yamashita, Takahiro, additional, Shimizu, Sunao, additional, Matsumoto, Mai, additional, Sawada, Kaori, additional, Jung, Songee, additional, Tokuda, Itoyo, additional, Misawa, Mina, additional, Suzuki, Shigenori, additional, Ushida, Yusuke, additional, Mikami, Tatsuya, additional, Itoh, Ken, additional, and Suganuma, Hiroyuki, additional

Published
2023
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