東京大学 · 医学
Abe教授の研究室は、音声変換技術とがんのエピジェネティクスを両輪に研究を進めています。音声変換分野では、ベクトル量子化とスペクトルマッピングを応用した高精度な声の個性制御技術を開発しており、性別や話者間の音声変換において優れた音声品質を実現しています。一方、がん研究では神経芽腫(neuroblastoma)の予後に関連するCpG島メチル化プロファイル(CIMP)の解明に貢献し、がんの発症メカニズムの理解を深めています。
Figures are computed from collected data and may differ slightly.
The authors propose a new voice conversion technique through vector quantization and spectrum mapping. The basic idea of this technique is to make mapping codebooks which represent the correspondence between different speakers' codebooks. The mapping codebooks for spectrum parameters, power values and pitch frequencies are separately generated using training utterances. This technique makes it possible to precisely control voice individuality. To evaluate the performance of this technique, heari
Neuroblastoma, one of the most common pediatric solid tumors, is characterized by two extreme disease courses, spontaneous regression and life-threatening progression. Here, we conducted a genome-wide search for differences in DNA methylation that distinguish between neuroblastomas of the two types. Three CpG islands (CGI) and two groups of CGIs were found to be methylated specifically in neuroblastomas with a poor prognosis. By quantitative analysis of 140 independent cases, methylation of all
A new voice conversion technique through vector quantization and spectrum mapping is proposed. This technique is based on mapping codebooks which represent the cor respondencebetween different speakers' codebooks. The mapping codebooks for spectrum parameters, power values, and pitch frequencies are separately generated using training utterances. This technique makes it possible to precisely control voice individuality. The performance of this technique is confirmed by spectrum distortion and pi
Our results indicate that the CIMP causes poor prognosis of NBLs by inducing methylation of multiple promoter CGIs with various incidences.
<i>Background</i>: Epidemiologic studies provide broad-based evidence that males are at greater risk of severe periodontal diseases than females. Our recent findings further revealed that male gender was an independent risk factor for gingival bleeding in late adolescents in Japan. Gingival health status has been reported to be affected by oral hygiene behavior. However, gender difference in this regard has not yet been clarified. <i>Methods</i>: We conducted a retrospective review of mandatory
Rat stomach carcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) are widely used as a model for differentiated-type human stomach carcinomas. Here, we analyzed expression profiles in five MNNG-induced rat stomach carcinomas by the high-density oligonucleotide microarray containing approximately 8000 probe sets. 244 and 208 genes were up- and down-regulated, respectively, by 3-fold and over in four or five carcinomas. Up-regulated genes included those involved in the extracellular ma
Mammalian germ cells undergo global reprogramming of DNA methylation during their development. Global DNA demethylation occurs around the time when the primordial germ cells colonize the embryonic gonads and this coincides with dynamic changes in chromatin composition. Global de novo DNA methylation takes place with remarkably different dynamics between the two sexes, prospermatogonia attaining methylation during fetal stages and oocytes attaining methylation postnatally. Our hypothesis was that
In this paper, we propose a life logger integrated with a remote controller, which is a personal device. It uses several sensors to collect the history of the user's control of consumer appliances as well as his/her actions, stores all data in real time before sending it to PCs or servers, and is small enough to carry at all times. The aim of data integration is to acquire the user's context from his/her actions; personalized services are then provided that suit the context. We develop a prototy
A voice conversion algorithm that uses speech segments as conversion units is proposed. Input speech is decomposed into speech segments by a speech recognition module, and the segments are replaced by speech segments uttered by another speaker. This algorithm makes it possible to convert not only the static characteristics but also the dynamic characteristics of speaker individuality. The proposed voice conversion algorithm was used with two male speakers. Spectrum distortion between target spee
The goal of cross-language voice conversion is to preserve the speech characteristics of one speaker when that speaker's speech is translated and used to synthesize speech in another language. In this paper, two preliminary studies, i.e., a statistical analysis of spectrum differences in different languages and the first attempt at a cross-language voice conversion, are reported. Speech uttered by a bilingual speaker is analyzed to examine spectrum difference between English and Japanese. Experi
OLs at high risk for malignant transformation were associated with aberrant promoter methylation of multiple genes.
First, the part of spectral difference that is due to the difference in language is assessed. This is investigated using a bilingual speaker's speech data. It is found that the interlanguage (between English and Japanese) difference is smaller than the interspeaker difference. Listening tests indicate that the difference between English and Japanese is very small. Second, a model for cross-language voice conversion is described. In this approach, voice conversion is considered a mapping problem
Hypermethylation of the 5' upstream region (5' region) of the human p16(CDKN2A) (p16) gene is known to cause silencing, which is involved in a wide range of human cancers. For the rat p16 gene, its 5' region has not been cloned, and it is uncertain whether surrogate use of exon 1 alpha is adequate for analysis of p16 silencing. In this study, we observed that methylation analysis of exon 1 alpha gave false positive results in three samples of normal rat mammary epithelia and in two of six primar
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