Elliptic Algebra and Integrable Models for Solitons on Noncummutative Torus T{\cal T}

We study the algebra ${\cal A}_n$ and the basis of the Hilbert space ${\cal H}_n$ in terms of the $\theta$ functions of the positions of $n$ solitons. Then we embed the Heisenberg group as the quantum operator factors in the representation of the transfer matrice of various integrable models. Finally we generalize our result to the generic $\theta$ case.Comment: Talk given by Bo-Yu Hou at the Joint APCTP-Nankai Symposium. Tianjin (PRC), Oct. 2001. To appear in the proceedings, to be published by Int. J. Mod. Phys. B. 7 pages, latex, no figure

Inhibition of EZH2 Promotes Human Embryonic Stem Cell Differentiation into Mesoderm by Reducing H3K27me3.

Mesoderm derived from human embryonic stem cells (hESCs) is a major source of the mesenchymal stem/stromal cells (MSCs) that can differentiate into osteoblasts and chondrocytes for tissue regeneration. While significant progress has been made in understanding of molecular mechanisms of hESC differentiation into mesodermal cells, little is known about epigenetic factors controlling hESC fate toward mesoderm and MSCs. Identifying potential epigenetic factors that control hESC differentiation will undoubtedly lead to advancements in regenerative medicine. Here, we conducted an epigenome-wide analysis of hESCs and MSCs and uncovered that EZH2 was enriched in hESCs and was downregulated significantly in MSCs. The specific EZH2 inhibitor GSK126 directed hESC differentiation toward mesoderm and generated more MSCs by reducing H3K27me3. Our results provide insights into epigenetic landscapes of hESCs and MSCs and suggest that inhibiting EZH2 promotes mesodermal differentiation of hESCs

The Radiation Structure of PSR B2016++28 Observed with FAST

With the largest dish Five-hundred-meter Aperture Spherical radio Telescope (FAST), both the mean and single pulses of PSR B2016$+$28, especially including the single-pulse structure, are investigated in detail in this study. The mean pulse profiles at different frequencies can be well fitted in a conal model, and the peak separation of intensity-dependent pulse profiles increases with intensity. The integrated pulses are obviously frequency dependent (pulse width decreases by $\sim\,20\%$ as frequency increases from 300 MHz to 750 MHz), but the structure of single pulses changes slightly (the corresponding correlation scale decreases by only $\sim\,1\%$). This disparity between mean and single pulses provides independent evidence for the existence of the RS-type vacuum inner gap, indicating a strong bond between particles on the pulsar surface. Diffused drifting sub-pulses are analyzed. The results show that the modulation period along pulse series ($P_3$) is positively correlated to the separation between two adjacent sub-pulses ($P_2$). This correlation may hint a rough surface on the pulsar, eventually resulting in the irregular drift of sparks. All the observational results may have significant implications in the dynamics of pulsar magnetosphere and are discussed extensively in this paper.Comment: Sci. China-Phys. Mech. Astron. 62, 959505 (2019

Reciprocal learning in mathematics education: An interactive study between two Canadian and Chinese elementary schools

In this study, the researchers go beyond the back-and-forth debates on the East-West educational paradigms that often arise from comparative studies, and take a reciprocal learning approach to explore in-depth the commonalities and differences in mathematics education between two Canadian and Chinese elementary schools. Research data were collected through direct and indirect interactions between the pair of research schools, including Skype meetings; formal and informal conversations with teachers and administrators; and the sharing/exchange of documents, texts, teaching materials, and resources. Results show that there is a common emphasis on some thematic issues in the teaching and learning of mathematics including the use of manipulatives, multiple solutions to mathematical problems, and parental involvement, but also some differences between the two schools in teachers’ strategies for teaching problem solving, students’ learning tendencies and schools’ supports for Special Needs students. The researchers conclude that the dichotomies of the East-West educational paradigms need to be further, and more deeply re-examined