Silver(I)-Ion-Mediated Cytosine-Containing Base Pairs: Metal Ion Specificity for Duplex Stabilization and Susceptibility toward DNA Polymerases

Spectroscopic characterization of Ag^I-ion-mediated C-Ag^I-A and C-Ag^I-T base pairs found in primer extension reactions catalyzed by DNA polymerases was conducted. UV melting experiments revealed that C-A and C-T mismatched base pairs in oligodeoxynucleotide duplexes are specifically stabilized by Ag^I ions in 1:1 stoichiometry in the same manner as a C-C mismatched base pair. Although the stability of the mismatched base pairs in the absence of Ag^I ions is in the order C-A≈C-T>C-C, the stabilizing effect of Ag^I ions follows the order C-C>C-A≈C-T. However, the comparative susceptibility of dNTPs to Ag^I-mediated enzymatic incorporation into the site opposite templating C is dATP>dTTP≫dCTP, as reported. The net charge, as well as the size and/or shape complementarity of the metal-mediated base pairs, or the stabilities of mismatched base pairs in the absence of metal ions, would be more important than the stability of the metallo-base pairs in the replicating reaction catalyzed by DNA polymerases.     

Polarity Effect and Electromagnetic Radiation of Partial Discharge Accompanying Growth of Electrical Tree

We have investigated the characteristics of radiated electromagnetic (EM) waves from positive and negative partial discharges (PD) in epoxy resin and cross‐linked polyethylene. We found that there is a correlation among the EM level from PD, the positive PD current, and electrical trees. Therefore, the growth of an electrical tree produces a lot of positive PD. We have also investigated the characteristics of the frequency region of EM waves from PD in air, insulating oil, and liquid epoxy in addition to the above insulators. EM waves were detected in the frequency region of 40 MHz to 300 MHz from positive and negative PD in epoxy resin and cross‐linked polyethylene. EM waves were also detected in the frequency region of 40 MHz to 150 MHz from positive and negative PD in air. In the case of insulating oil and liquid epoxy, EM waves were detected in the frequency regions of 40 MHz to 150 MHz from positive PD, and 40 MHz to 250 MHz from negative PD. The frequency region differed depending on the material and the discharge polarity. Our investigation indicates that the cause is differences in electric field strength at the time of PD occurrence.     

In Vivo Electrophysiology of Peptidergic Neurons in Deep Layers of the Lumbar Spinal Cord after Optogenetic Stimulation of Hypothalamic Paraventricular Oxytocin Neurons in Rats

The spinal ejaculation generator (SEG) is located in the central gray (lamina X) of the rat lumbar spinal cord and plays a pivotal role in the ejaculatory reflex. We recently reported that SEG neurons express the oxytocin receptor and are activated by oxytocin projections from the paraventricular nucleus of hypothalamus (PVH). However, it is unknown whether the SEG responds to oxytocin in vivo. In this study, we analyzed the characteristics of the brain–spinal cord neural circuit that controls male sexual function using a newly developed in vivo electrophysiological technique. Optogenetic stimulation of the PVH of rats expressing channel rhodopsin under the oxytocin receptor promoter increased the spontaneous firing of most lamina X SEG neurons. This is the first demonstration of the in vivo electrical response from the deeper (lamina X) neurons in the spinal cord. Furthermore, we succeeded in the in vivo whole-cell recordings of lamina X neurons. In vivo whole-cell recordings may reveal the features of lamina X SEG neurons, including differences in neurotransmitters and response to stimulation. Taken together, these results suggest that in vivo electrophysiological stimulation can elucidate the neurophysiological response of a variety of spinal neurons during male sexual behavior.     

Methanogenic digestion using mixed substrate of acetic, propionic and butyric acids

Experiments on methanogenic digestion using high concentrations of mixed substrate were conducted. The major intermediate products of anaerobic digestion such as acetic, propionic and butyric acids were mixed in a ratio of 2:1:1 (COD basis), respectively, and used as a substrate for feeding into continuous-flow chemostat reactors maintained at 35°C. These reactors were operated stably at higher feed substrate concentrations and shorter hydraulic retention times (HRT) than those of using a single component of volatile fatty acids as a substrate. At an HRT of 4.43 days, the methanogenesis occurred normally up to a feed substrate concentration of 70,000 mg COD I⁻¹. At a feed substrate concentration of 20,000 mg COD I⁻¹, the methanogenesis occurred normally up to an HRT of 2.91 days and the minimum SRT for microbial populations was calculated to be 2.42 days. An increase in feed substrate concentration adversely affected the propionate degradation strikingly, while a decrease in HRT significantly adversely affected the acetate and propionate degradation. The methane production was 0.301 g⁻¹ COD utilized, and it was independent of the feed substrate concentration and HRT. Bacilli were predominant in all reactors, but sarcinae appeared in the reactors with high feed substrate concentrations and short HRTs. Phenomena in digester failure due to methanogen washout were also observed.     

Olympic Technologies

The Olympic Games bring tremendous impacts to host cities, yet little attention has been paid to the variety and novelty in urban technologies that are introduced through the mega-event vehicle. This paper argues that urban transformation associated with the Olympic Games increasingly spans the technological sphere. As a path-breaker the Olympic bid of Tokyo foreshadows a technological revolution that will make the capital of Japan the most advanced urban technology metropolis in the world. This is significant, as this pioneer for the city of the future may yield many valuable insights given the rapid implementation and acceleration of technological innovation proceeding into 2020. Consequently, lessons on how this technology may impact our society can be derived.     

由疏散地图到城市建设的平台 ——论“逃生地图”的可能性

所谓“疏散地形时间地图”（一般叫逃生地图）是指从绘制详细的疏散地图到致力于震后重建方法论的一系列举措。这一系列举措不仅保护了众多今后可能会没落的地域文化。而且还从地震中吸取教训,在进行建设和规划以人命优先为主旨的城市的前提下尝试着对地域进行改变。本文主要介绍了“逃生地图”概要、地方研讨会的地图效果以及逃生地图在汽车导航服务方面的应用等。     

The roles of the Trommsdorff–Norrish effect in phase separation of binary polymer mixtures induced by photopolymerization

Influence of the Trommsdorff–Norrish (T–N) effect on the phase separation of methyl methacrylate (MMA)/poly(ethyl acrylate) (PEA) mixtures undergoing photo-polymerization was examined by a combination of several experimental techniques. By FT-IR spectroscopy, it was found that the polymerization conversion explosively increases at the onset of this T–N effect. The characteristic irradiation time τ at which this effect occurs, strongly depends on the light intensity and gradually shifts to early time as the irradiation intensity increases. The shrinkage of the mixture observed in situ by laser-scanning confocal microscopy exhibits a transition at a particular irradiation time which is slightly longer than the characteristic time τ. By gel permeation chromatography (GPC), it was found that the molecular weight of the resulting PMMA was almost unchanged before τ and suddenly increases about an order of magnitude after the onset of the auto-acceleration effect. Finally, the characteristic length scales of the morphology also quickly increase with irradiation time and are eventually frozen by this T–N effect. These experimental results indicate that the Trommsdorff–Norrish effect plays an important role in the kinetic processes of polymerization-induced phase separation, suggesting an efficient tool to control the morphology of the polymerizing mixture.     

Chain stiffness and chain conformation of poly(α-methylene-γ-butyrolactone) in dilute solutions

The chain stiffness and local chain conformation of atactic poly(α-methylene-γ-butyrolactone) (PMBL), which is a side chain cyclic structural analog of poly(methyl methacrylate) (PMMA), with a weight-average molecular weight (M_w) ranging from 2.8 × 10³ to 2.6 × 10⁶ in N,N-dimethylformamide (DMF) and γ-butyrolactone (GBL) were characterized by size exclusion chromatography with a multi-angle light-scattering detector (SEC-MALS) and synchrotron radiation small-angle X-ray scattering (SAXS). Based on the Kratky-Porod worm-like chain model, the scattering functions and the M_w dependence of z-average root-mean-square radius of gyration <S²>_z^1/2 yielded the Kuhn segment lengths λ⁻¹, the diameter of the PMBL chains d, and the excluded-volume strengths in DMF and GBL. The local conformation of atactic PMBL in DMF and GBL were slightly larger than those of atactic PMMA, due to the presence of the conformationally rigid lactone ring structure.     

Autonomous Variable‐Resolution Map Building for Mobile Robots in Unknown Environments

This paper presents a method that allows simultaneous map building and path planning for mobile robots in unknown environments. A graphical representation of a workspace in variable resolutions is constructed using measurement data obtained by omnidirectional distance sensors. At the same time, a search for a feasible path to the target destination is executed using the constructed graph map. The proposed method is evaluated by performing simulations and experiments using an omnidirectional mobile robot equipped with laser range finders. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 59–69, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22493