Essential Role for miR-196a in Brown Adipogenesis of White Fat Progenitor Cells

Brown adipocytes can differentiate from white fat progenitor cells in mice exposed to cold or β3-adrenergic stimulation, and this process is regulated by a microRNA that regulates the expression of Hoxc8, a master regulator of brown adipogenesis

Study on Analyzing Individuality of Instrurment Sounds Using Non-negative Matrix Factorization

Nowadays, sound production softwares are popularly used in computer music. However, to express individuality of instrument sounds, especially piano sounds, is still a challenging problem. Though individuality of a piano sound exists in its harmonic structures, the temporal variation of the harmonic structures has not been taken into consideration in the previous researches. This paper aims to study the individuality of piano sounds in their harmonic structures and temporal variation. Analyses are conducted using Non-negative Matrix Factorization (NMF). The results show that the temporal variation of high frequency components above 4 kHz is important to distinguish upright pianos and grand pianos. In addition, grand piano sounds are divided into 4 types by individuality, and individuality of upright piano sounds is observed by NMF analysis with fixing parts of basis matrix

Passivation of textured crystalline silicon with small pyramids by silicon nitride films formed by catalytic chemical vapor deposition and phosphorus catalytic impurity doping

Silicon nitride (SiN_x) films formed by catalytic chemical vapor deposition (Cat-CVD) and phosphorus (P) catalytic impurity doping (Cat-doping) are applied on textured crystalline silicon (c-Si) wafers with a pyramid size of 1–2 μm to reduce the surface recombination of minority carriers. SiN_x single layer passivation realizes a surface recombination velocity (SRV) of less than 10 cm/s. The addition of a P Cat-doped layer results in a reduction in a SRV to ～7 cm/s owing to field-effect passivation. These values are comparable to those obtained in our previous study for textured c-Si surface with larger-sized pyramids, indicating the high passivation ability of Cat-CVD SiN_x films and P Cat-doping independent of the size of pyramids. In addition to the double-side textured wafers, we also prepare a single-side textured wafer using Cat-CVD SiN_x as an etching barrier. We find that Cat-CVD SiN_x films can be utilized as an etching barrier against alkali solution, and a high effective minority carrier lifetime (τ_) of 2.3 ms has been obtained by the passivation with Cat-CVD SiN_x films. These achievements will contribute to an improvement in the performance of back-contact c-Si solar cells