Characteristics of shooting time of the world’s top level male archery athletes

The purpose of this study was to clarify the characteristic features of the shooting time of the world’s top-level male archery athletes. The matches used for this study were those from the 1/64th Elimination Round to the Finals in the Men’s Individual of the 44th World Outdoor Target Archery Championships. As representative of the world’s top athletes, the medalists from these competitions were studied; the mean time and the coefficient of variation of the mean for each phase of shooting were calculated, and compared to those of all the athletes who competed in matches from the 1/64th Elimination Round to the Finals. The results of the study showed for the different phases of shooting, the preparatory phase had the longest mean time regardless of the resulting scores (p＜0.05); the mean’s coefficient of variation was also large for this phase (p＜0.05). The mean time taken by the medalists for the preparatory phase was shorter than the mean time taken by the competing athletes for the same phase (p＜0.01). These results suggest that the characteristic feature of shooting time of the world’s top-level male archery athletes was a shorter duration of the preparatory phase

Tributyltin Inhibits Neural Induction of Human Induced Pluripotent Stem Cells

Tributyltin (TBT), one of the organotin compounds, is a well-known environmental pollutant. In our recent study, we reported that TBT induces mitochondrial dysfunction, in human-induced pluripotent stem cells (iPSCs) through the degradation of mitofusin1 (Mfn1), which is a mitochondrial fusion factor. However, the effect of TBT toxicity on the developmental process of iPSCs was not clear. The present study examined the effect of TBT on the differentiation of iPSCs into the ectodermal, mesodermal, and endodermal germ layers. We found that exposure to nanomolar concentration of TBT (50 nM) selectively inhibited the induction of iPSCs into the ectoderm, which is the first step in neurogenesis. We further assessed the effect of TBT on neural differentiation and found that it reduced the expression of several neural differentiation marker genes, which were also downregulated by Mfn1 knockdown in iPSCs. Taken together, these results indicate that TBT induces developmental neurotoxicity via Mfn1-mediated mitochondrial dysfunction in iPSCs

Reconstruction of the P2X2 Receptor Reveals a Vase-Shaped Structure with Lateral Tunnels above the Membrane

SummaryIn response to the intercellular messenger ATP, P2X receptors transfer various sensory information, including pain. Here we have reconstructed the structure of the P2X2 receptor at 15 Å resolution from more than 90,000 particle images, taken with a cryo-electron microscope equipped with a helium-cooled stage. This three-dimensional depiction, presumably in a closed state, revealed an elongated vase-shaped structure 202 Å in height and 160 Å in major diameter. The extracellular and transmembrane domains present a two-layered structure, in which a sparse outer layer surrounds a pore-forming inner density. The decreased diameter of a putative ion-conducting pathway at the middle of the membrane was considered to be the narrowest part of the pore, which has been predicted from electrophysiological studies. The sparse, extended structure of the P2X2 receptor indicates a loose assembly of subunits, which could be a basis for the activation-dependent pore dilation of P2X receptors

Simulation study of electron drift and gas multiplication in Micro Pixel Chamber

The physical processes of charge collection and gas multiplication of a Micro Pixel Chamber (mu-PIC) were studied in detail using a three-dimensional simulation. The collection efficiencies of primary electrons and gas multiplication factors were calculated for several electrode structures. Based on those studies, we analyzed the optimization of the electrode structure of the mu-PIC, in order to obtain a high gas gain of more than 10^4 and a simultaneous suppression of discharges. Consequently, we found that these characteristics strongly depend on the substrate thickness and the anode diameter of the mu-PIC. In addition, a gas gain of 10^5 would be expected for a mu-PIC having a thick substrate of > 150um.Comment: 16 pages, 14 figures, Submitted to Nucl. Instr. Methods

Performance of a Time-Projection-Chamber with a Large-Area Micro-Pixel-Chamber Readout

A micro time-projection-chamber (micro-TPC) with a detection volume of 23*28*31 cm^3 was developed, and its fundamental performance was examined. The micro-TPC consists of a micro pixel chamber with a detection area of 31*31 cm^2 as a two-dimensional imaging device and a gas electron multiplier with an effective area of 23*28 cm^2 as a pre-gas-multiplier. The micro-TPC was operated at a gas gain of 50,000, and energy resolutions and spatial resolutions were measured.Comment: 4 pages, 7 figures, proceedings of IWORID