Quantum Field Theories with Tensor Renormalization Group

We report recent progress on the application of the tensor renormalization group (TRG) to quantum field theories pursued by the Tsukuba group. We explain how to treat the scalar, fermion, and gauge theories with the TRG method presenting the results for the phase transitions in the (3+1)-dimensional ((3+1)$d$) complex $\phi^4$ theory at finite density, (1+1)$d$ pure U(1) lattice gauge theory with a $\theta$ term, (3+1)$d$ Nambu--Jona-Lasinio model at finite density and (1+1)$d$ and (2+1)$d$ Hubbard models at an arbitrary chemical potential. It is demonstrated that the TRG method is free from the sign problem in practical calculations and applicable to the four-dimensional models.Comment: 25 pages, 20 figures, Proceedings of the 38th International Symposium on Lattice Field Theory, LATTICE2021 26th-30th July 2021, Zoom/Gather@Massachusetts Institute of Technolog

Detecting Train Delays using Railway Network Topology in Twitter

This paper presents a novel train delay detection method based on topic propagation analysis of geo-tagged tweets between railway stations. Our goal is to detect traffic accidents and to predict train delays in railway network topology by tracing how relevant tweets propagate in real space and cyberspace. In our method, we utilize railway network as the topology of real space, and extract the topology of social network that is mapped on the railway network. This permits observing the influence of delays on stations with a few tweets, or predicting related tweets of affected stations even if the tweets contain indirect topics about delays

Activation of an Estrogen/ Estrogen Receptor Signaling by BIG3 Through Its Inhibitory Effect on Nuclear Transport of PHB2/REA in Breast Cancer

Breast cancer is known to be a hormone-dependent disease, and estrogens through an interaction with estrogen receptor (ER) enhance the proliferative and metastatic activity of breast tumor cells. Here we show a critical role of transactivation of BIG3, brefeldin A-inhibited guanine nucleotide-exchange protein 3, in activation of the estrogen/ER signaling in breast cancer cells. Knocking-down of BIG3 expression with small-interfering RNA (siRNA) drastically suppressed the growth of breast cancer cells. Subsequent co-immunoprecipitation and immunoblotting assays revealed an interaction of BIG3 with prohibitin 2/repressor of estrogen receptor activity (PHB2/REA). When BIG3 was absent, stimulation of estradiol caused the translocation of PHB2/REA to the nucleus, enhanced the interaction of PHB2/REA and ER[alpha], and resulted in suppression of the ER[alpha]; transcriptional activity. On the other hand, when BIG3 was present, BIG3 trapped PHB2/REA in cytoplasm and inhibited its nuclear translocation, and caused enhancement of ER[alpha]; transcriptional activity. Our results imply that BIG3 overexpression is one of the important mechanisms causing the activation of the estrogen/ER[alpha]; signaling pathway in the hormone-related growth of breast cancer cells

Vibrio proteolyticus No. 442, a potential probiotic for tiger puffer, Takifugu rubripes

The efficacy of Vibrio proteolyticus No. 442 as a probiotic in preventing opportunistic infections caused by Vibrionaceae in tiger puffer, Takifugu rubripes, was evaluated. Two strains of Listonella anguillarum, IFO 13266T and Obama 5, were used as target bacteria. The antimicrobial activity of V. proteolyticus No. 442 peaks at approximately 25°C and is absent at temperatures at 15°C or above 35°C. This activity is also most pronounced at an oxygen concentration of 21% and is undetectable under anaerobic conditions. Using these characteristics, V. proteolyticus No. 442 and L. anguillarum IFO 13266 were co-cultured under aerobic and anaerobic conditions. The findings indicated that under aerobic conditions, L. anguillarum IFO 13266 was eradicated following a 48-hour incubation at 25°C, while under anaerobic conditions, both species maintained high bacterial densities. Consequently, the oral administration of the diets supplemented with V. proteolyticus No. 442 to juvenile tiger puffers for seven days resulted in a decrease in the density of Vibrionaceae (excluding V. proteolyticus) by two to three orders of magnitude in the gut, and by one to two orders of magnitude in the rearing water. Future research needs to investigate the long-term efficacy of V. proteolyticus as a probiotic, and its pathogenicity, fish growth, administration methods, and storage strategies