Arithmetic of the moduli of hyperelliptic curves and principally polarized Abelian surfaces over global fields

We use geometric methods to establish an upper bound for counting stable hyperelliptic curves with a marked Weierstrass section ordered by height of discriminant at most $\mathcal{B}$ over $\mathbb{P}^{1}_{\mathbb{F}_q}$ with characteristic $p > 2g+1$; the acquired estimate is of order $\mathcal{O}_q\left( \mathcal{B}^{\frac{2g+3}{4g+2}} \right)$. We sharpen the estimate for each genus $g \ge 2$; specifically when $g=2$, this renders an estimate on the number of principally polarized Abelian surfaces over $\mathbb{F}_q(t)$. Through the global fields analogy, we formulate analogous new heuristics for counting stable hyperelliptic curves with a marked rational Weierstrass point or principally polarized Abelian surfaces over $\mathbb{Q}$. In Appendix, we determine the sharp estimate for counting elliptic curves with prescribed level structures or multiple marked points over $\mathbb{P}^{1}_{\mathbb{F}_q}$.Comment: 35 pages. The paper has been substantially reorganized throughout with a significantly improved Introduction. The Appendix (reinforced by Changho Han) has been integrated from arXiv:2002.06527. Comments welcome

Hierarchical Coding for Distributed Computing

Coding for distributed computing supports low-latency computation by relieving the burden of straggling workers. While most existing works assume a simple master-worker model, we consider a hierarchical computational structure consisting of groups of workers, motivated by the need to reflect the architectures of real-world distributed computing systems. In this work, we propose a hierarchical coding scheme for this model, as well as analyze its decoding cost and expected computation time. Specifically, we first provide upper and lower bounds on the expected computing time of the proposed scheme. We also show that our scheme enables efficient parallel decoding, thus reducing decoding costs by orders of magnitude over non-hierarchical schemes. When considering both decoding cost and computing time, the proposed hierarchical coding is shown to outperform existing schemes in many practical scenarios.Comment: 7 pages, part of the paper is submitted to ISIT201

High-speed and high-SNR photoacoustic microscopy based on a galvanometer mirror in non-conducting liquid

Optical-resolution photoacoustic microscopy (OR-PAM), a promising microscopic imaging technique with high ultrasound resolution and superior optical sensitivity, can provide anatomical, functional, and molecular information at scales ranging from the microvasculature to single red blood cells. In particular, real-time OR-PAM imaging with a high signal-to-noise ratio (SNR) is a prerequisite for widespread use in preclinical and clinical applications. Although several technical approaches have been pursued to simultaneously improve the imaging speed and SNR of OR-PAM, they are bulky, complex, not sensitive, and/or not actually real-time. In this paper, we demonstrate a simple and novel OR-PAM technique which is based on a typical galvanometer immersed in non-conducting liquid. Using an opto-ultrasound combiner, this OR-PAM system achieves a high SNR and fast imaging speed. It takes only 2 seconds to acquire a volumetric image with a wide field of view (FOV) of 4 x 8 mm(2) along the X and Y axes, respectively. The measured lateral and axial resolutions are 6.0 and 37.7 mu m, respectively. Finally, as a demonstration of the system's capability, we successfully imaged the microvasculature in a mouse ear in vivo. Our new method will contribute substantially to the popularization and commercialization of OR-PAM in various preclinical and clinical applications.11Ysciescopu

Determination of the thermoelectric properties of a skutterudite-based device at practical operating temperatures by impedance spectroscopy

Skutterudite-based thermoelectric materials are promising candidates for waste heat recovery applications at intermediate temperatures (300–500 °C) owing to their high dimensionless figure of merit and power factor. Recently, several researchers have reported the high performance of skutterudite-based thermoelectric devices obtained by optimizing the crystal structure and microstructure of skutterudite materials and developing metallization layers for device fabrication. Despite extensive research efforts toward maximizing the power density and thermoelectric conversion efficiency of skutterudite-based devices, the thermoelectric properties of such devices after fabrication remain largely unknown. Here, we systematically investigated the factors that affect the thermoelectric properties of skutterudite-based devices within the range of practical operating temperatures (23–450 °C). We successfully prepared a two-couple skutterudite-based device with titanium metallization layers on both sides of the thermoelectric legs and characterized it using scanning and transmission electron microscopy and specific contact resistance measurements. Impedance spectroscopy measurements of the two-couple skutterudite-based device revealed the figure of merit of the device and enabled the extraction of three key thermoelectric parameters (Seebeck coefficient, thermal conductivity, and electrical conductivity). The impedance spectra and extracted parameters depended strongly on the measurement temperature and were mainly attributable to the thermoelectric properties of skutterudite materials. These observations demonstrate the interplay between the properties of thermoelectric materials and devices and can aid in directing future research on thermoelectric device fabrication

Comprehensive genomic analyses associate UGT8 variants with musical ability in a Mongolian population

Background: Musical abilities such as recognising music and singing performance serve as means for communication and are instruments in sexual selection. Specific regions of the brain have been found to be activated by musical stimuli, but these have rarely been extended to the discovery of genes and molecules associated with musical ability. Methods: A total of 1008 individuals from 73 families were enrolled and a pitch-production accuracy test was applied to determine musical ability. To identify genetic loci and variants that contribute to musical ability, we conducted family-based linkage and association analyses, and incorporated the results with data from exome sequencing and array comparative genomic hybridisation analyses. Results: We found significant evidence of linkage at 4q23 with the nearest marker D4S2986 (LOD=3.1), whose supporting interval overlaps a previous study in Finnish families, and identified an intergenic single nucleotide polymorphism (SNP) $(rs1251078, p=8.4×10^{−17})$ near UGT8, a gene highly expressed in the central nervous system and known to act in brain organisation. In addition, a non-synonymous SNP in UGT8 was revealed to be highly associated with musical ability $(rs4148254, p=8.0×10^{−17})$, and a 6.2 kb copy number loss near UGT8 showed a plausible association with musical ability $(p=2.9×10^{−6})$. Conclusions: This study provides new insight into the genetics of musical ability, exemplifying a methodology to assign functional significance to synonymous and non-coding alleles by integrating multiple experimental methods

Spermidine-induced recovery of human dermal structure and barrier function by skin microbiome.

An unbalanced microbial ecosystem on the human skin is closely related to skin diseases and has been associated with inflammation and immune responses. However, little is known about the role of the skin microbiome on skin aging. Here, we report that the Streptococcus species improved the skin structure and barrier function, thereby contributing to anti-aging. Metagenomic analyses showed the abundance of Streptococcus in younger individuals or those having more elastic skin. Particularly, we isolated Streptococcus pneumoniae, Streptococcus infantis, and Streptococcus thermophilus from face of young individuals. Treatment with secretions of S. pneumoniae and S. infantis induced the expression of genes associated with the formation of skin structure and the skin barrier function in human skin cells. The application of culture supernatant including Streptococcal secretions on human skin showed marked improvements on skin phenotypes such as elasticity, hydration, and desquamation. Gene Ontology analysis revealed overlaps in spermidine biosynthetic and glycogen biosynthetic processes. Streptococcus-secreted spermidine contributed to the recovery of skin structure and barrier function through the upregulation of collagen and lipid synthesis in aged cells. Overall, our data suggest the role of skin microbiome into anti-aging and clinical applications

高温ブランケットシステムの為の液体リチウム鉛と先進材料の共存性に関する研究

京都大学0048新制・課程博士博士(エネルギー科学)甲第17916号エネ博第288号新制||エネ||60(附属図書館)30736京都大学大学院エネルギー科学研究科エネルギー変換科学専攻(主査)教授 小西 哲之, 教授 星出 敏彦, 教授 木村 晃彦学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDFA

Improvement of a Low Cost MEMS Inertial-GPS Integrated System Using Wavelet Denoising Techniques

In this paper, the wavelet denoising techniques using thresholding method are applied to the low cost micro electromechanical system (MEMS)-global positioning system(GPS) integrated system. This was done to improve the navigation performance. The low cost MEMS signals can be distorted with conventional pre-filtering method such as low-pass filtering method. However, wavelet denoising techniques using thresholding method do not distort the rapidly-changing signals. They can reduce the signal noise. This paper verified the improvement of the navigation performance compared to the conventional pre-filtering by simulation and experiment.DAPA/ADD/NGR