Enhanced floc formation by degP-deficient Escherichia coli cells in the presence of glycerol.

Flocculation is an aggregation phenomenon of microbial cells in which they form flocs or flakes. In this study, it was found that addition of glycerol to a complex glucose medium promoted spontaneous floc formation by an Escherichia coli degP-deficient mutant strain (ΔdegP) in a dose-dependent manner. In the presence of 10% (v/v) glycerol, the amount of floc formation (quantified as floc protein) reached its maximum value (230 mg/L), five times that in its absence. 10% (v/v) glycerol was the limit concentration that does not inhibit cell growth of ΔdegP strain. Glycerol was not consumed by ΔdegP cells during floc formation. To provide media having nearly the same viscosity as that containing 10% (v/v) glycerol, carboxymethyl cellulose (CMC) or polyvinylpyrrolidone (PVP) were added to medium as viscosifying agents. Floc formation was not promoted by increasing the medium viscosity with CMC or PVP. However, addition of ethylene glycol also significantly promoted floc formation in the same manner as glycerol. Addition of short-chain polyols decreased the number of viable ΔdegP cells in the floc structure and enhanced outer membrane vesicle (OMV) production by ΔdegP cells; polyols-induced damage on the outer membrane of ΔdegP cells may contribute to the promoted floc formation.

MEMS vibrational energy harvesters.

In this paper, we look into the fundamental mechanism to retrieve the power from physical vibrations by using microelectromechanical systems (MEMS) energy harvesters. An analytical model is presented for the velocity-damped resonant generator (VDRG) that delivers electrical power through the power enhancement mechanism using the mechanical resonance of a suspended mass. Deliverable power is also analytically discussed with respect to the theoretical limit, and a view to understand the VDRG behaviors is presented in association with the impedance matching condition and the quality factors. Mechano-electric power conversions including electrostatic induction, electromagnetic induction, and piezoelectric effect are discussed to study the scaling effect. Recent examples of MEMS VDRGs are reviewed and evaluated in terms of the power density.

Feasibility and psychometric properties of the UCLA PTSD reaction index for DSM-5 in japanese youth: A multi-site study.

The purpose of this study was to determine the reliability and validity of the UCLA PTSD Reaction Index for DSM-5 (PTSD-RI-5) among Japanese youth. This is the first study to explore psychometrics of the DSM-5 version of the PTSD-RI-5, as well as the first multisite study of an Asian population. This article presents psychometric characteristics of the PTSD-RI-5 derived from a sample of Japanese children and adolescents (N = 318). The PTSD-RI-5 total scale displayed good internal consistency reliability (α = 0.85). Correlations of PTSD-RI scores with the posttraumatic stress scores on the TSCC-A for the entire sample provided evidence of convergent validity. The four-factor structure of the PTSD-RI-5 was supported through confirmatory factor analysis in this sample. In conclusion, a DSM-5 version of the PTSD-RI-5 can be regarded as an adequate instrument for clinical and research purposes in Japan.

Development of a Cantilever-Type Electrostatic Energy Harvester and Its Charging Characteristics on a Highway Viaduct.

We have developed a micro-electro-mechanical systems (MEMS) electrostatic vibratory power generator with over 100 µ W RMS of (root-mean-square) output electric power under 0.03 G RMS (G: the acceleration of gravity) accelerations. The device is made of a silicon-on-insulator (SOI) wafer and is fabricated by silicon micromachining technology. An electret built-in potential is given to the device by electrothermal polarization in silicon oxide using potassium ions. The force factor, which is defined by a proportional coefficient of the output current with respect to the vibration velocity, is 2.34 × 10 - 4 C/m; this large value allows the developed vibration power generator to have a very high power efficiency of 80.7%. We have also demonstrated a charging experiment by using an environmental acceleration waveform with an average amplitude of about 0.03 G RMS taken at a viaduct of a highway, and we obtained 4.8 mJ of electric energy stored in a 44 µ F capacitor in 90 min.