Successful reprogramming of epiblast stem cells by blocking nuclear localization of β-catenin.

Epiblast stem cells (EpiSCs) in mice and rats are primed pluripotent stem cells (PSCs). They barely contribute to chimeric embryos when injected into blastocysts. Reprogramming of EpiSCs to embryonic stem cell (ESC)-like cells (rESCs) may occur in response to LIF-STAT3 signaling; however, low reprogramming efficiency hampers potential use of rESCs in generating chimeras. Here, we describe dramatic improvement of conversion efficiency from primed to naive-like PSCs through upregulation of E-cadherin in the presence of the cytokine LIF. Analysis revealed that blocking nuclear localization of β-CATENIN with small-molecule inhibitors significantly enhances reprogramming efficiency of mouse EpiSCs. Although activation of Wnt/β-catenin signals has been thought desirable for maintenance of naive PSCs, this study provides the evidence that inhibition of nuclear translocation of β-CATENIN enhances conversion of mouse EpiSCs to naive-like PSCs (rESCs). This affords better understanding of gene regulatory circuits underlying pluripotency and reprogramming of PSCs

Recent progress in silica aerogel Cherenkov radiator

In this paper, we present recent progress in the development of hydrophobic silica aerogel as a Cherenkov radiator. In addition to the conventional method, the recently developed pin-drying method for producing high-refractive-index aerogels with high transparency was studied in detail. Optical qualities and large tile handling for crack-free aerogels were investigated. Sufficient photons were detected from high-performance aerogels in a beam test.Comment: Proceedings of 2nd International Conference on Technology and Instrumentation in Particle Physics (TIPP 2011), to be published in Physics Procedia, 8 pages, 7 figure

The Cause of Ground Fissures Radiating From the Footing of a Bridge Pie Generated by the 1995 Great Hanshin Earthquake

After the 1995 Great Hanshin Earthquake, ground fissures were found to have radiated from the footing of a bridge pier. Simple experimental and numerical studies were carried out to investigate the cause of these fissures. This paper clarified that the ground fissures appeared not as a result of the force due to the lateral spreading of the liquefied soil acting to the back of the footing of the bridge pier, but due to the movement of the ground behind the riverbank toward the river caused by the collapse of the riverbank

Solute dispersion in a variably saturated sand

The understanding of solute dispersion in unsaturated porous media is still nascent. This work focuses on the measurement of solute dispersion in porous media at various levels of pore-volume saturation and on the parameterization of longitudinal dispersivity in terms of the saturation ratio and a soil's textural characteristics. The dispersion coefficient was determined in partly saturated columns packed with Toyoura sand or glass beads under steady state flow. A 0.0282 N sodium chloride solution was used as a nonreactive tracer in a series of laboratory experiments in which, for a fixed water content, the average pore-water velocity was varied. The column experiments showed that the dispersion coefficient increases linearly with increasing water velocity for a fixed water content and that the slope of the dispersion coefficient versus water velocity relationship diminishes as the water content is increased. The Peclet number (Pe) was fitted to the experimental tracer data by a nonlinear function Pe = aSrb, in which Sr is the saturation ratio and a and b are textured-dependent parameters. The dispersivity (α, in centimeters) of the test columns' porous media was then estimated in terms of the saturation ratio and the median grain size (d50, in centimeters) by the power law α = d50/Pe = d50/aSrb, which provides a specific functional relationship among a porous medium's dispersion properties, the saturation ratio, and the medium's textural characteristics

Microfluidic cell engineering on high-density microelectrode arrays for assessing structure-function relationships in living neuronal networks

Neuronal networks in dissociated culture combined with cell engineering technology offer a pivotal platform to constructively explore the relationship between structure and function in living neuronal networks. Here, we fabricated defined neuronal networks possessing a modular architecture on high-density microelectrode arrays (HD-MEAs), a state-of-the-art electrophysiological tool for recording neural activity with high spatial and temporal resolutions. We first established a surface coating protocol using a cell-permissive hydrogel to stably attach polydimethylsiloxane microfluidic film on the HD-MEA. We then recorded the spontaneous neural activity of the engineered neuronal network, which revealed an important portrait of the engineered neuronal network--modular architecture enhances functional complexity by reducing the excessive neural correlation between spatially segregated modules. The results of this study highlight the impact of HD-MEA recordings combined with cell engineering technologies as a novel tool in neuroscience to constructively assess the structure-function relationships in neuronal networks.Comment: 18 pages, 5 figure