Quantitative detection of previously characterized syntrophic bacteria in anaerobic wastewater treatment systems by sequence-specific rRNA cleavage method

Quantitative monitoring method of two important trophic groups of bacteria in methanogenic communities was established and applied to six different anaerobic processes. The method we employed was based upon our previous sequence-specific rRNA cleavage method that allows quantification of rRNA of target groups so that the populations reflecting in situ activity could be determined. We constructed a set of scissor probes targeting the Chloroflexi group known as ‘semi-syntrophic’ heterotrophic bacteria and fatty acid-oxidizing syntrophs to determine their relative abundance in the processes. By using the method, we found that several reactors harbored a large amount of organisms belonging to the phylum Chloroflexi accounting for up to 20% of the total prokaryotic populations. Propionate-oxidizing syntrophs, Syntrophobacter, Smithella and Pelotomaculum were also found to be significant comprising up to 3.9% of the total populations, but their distribution is highly dependent on the process examined. This is the first clear, non-PCR based quantitative evidence that those organisms play active roles under in situ methanogenic conditions.     

A model analysis of clean development mechanisms to reduce both CO2 and SO2 emissions between Japan and China

It is necessary for Japan to support the development of desulfurization policies of China to solve global and local environmental problems. This study proposes a “double clean development mechanism” to reduce both CO₂ and SO₂ emissions at the same time. The purpose of this study is to investigate the consequences for both countries' energy economies of following double clean development mechanism between Japan and China. A dynamic optimization model is developed to estimate the effects of Japanese investments in China for carbon dioxide recovery-disposal and emission desulfurization technologies. The simulation results suggest that a double clean development mechanism can effectively mitigate the damage caused by SO₂ emissions because the clean development mechanism itself can reduce SO₂ emissions, e.g. by switching to fuels. However, China might not be willing to accept restrictions on SO₂ emissions. This study also examines whether China will be able to maintain high growth rates with a clean development mechanism under the CO₂ and SO₂ restriction. The analysis shows that increasing the upper limit of investment from Japan to China can enhance the economies of the both nations. The effect of nuclear power installation on economic performance is also investigated for the both nations.     

Evaluation of noise filter characteristics by discrete wavelet transformation

In this paper, the authors propose a wavelet analysis technique to evaluate the noise filtering characteristics of filters. To analyze noise problems, many people have used Fourier analysis. But the Fourier spectrum reveals only frequency information. Therefore, it is difficult to obtain noise waveforms from the Fourier spectrum. To overcome this difficulty, we have employed the wavelet analysis technique. Wavelet analysis makes it possible to get time domain as well as frequency domain information. It is shown that wavelet analysis is a promising methodology for noise filter characteristic evaluation. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(3): 1–8, 1997     

Analysis of Selenoprotein F Binding to UDP-Glucose:Glycoprotein Glucosyltransferase (UGGT) by a Photoreactive Crosslinker

In the endoplasmic reticulum glycoprotein quality control system, UDP-glucose : glycoprotein glucosyltransferase (UGGT) functions as a folding sensor. Although it is known to form a heterodimer with selenoprotein F (SelenoF), the details of the complex formation remain obscure. A pulldown assay using co-transfected SelenoF and truncated mutants of human UGGT1 (HUGT1) revealed that SelenoF binds to the TRXL2 domain of HUGT1. Additionally, a newly developed photoaffinity crosslinker was selectively introduced into cysteine residues of recombinant SelenoF to determine the spatial orientation of SelenoF to HUGT1. The crosslinking experiments showed that SelenoF formed a covalent bond with amino acids in the TRXL3 region and the interdomain between βS2 and GT24 of HUGT1 via the synthetic crosslinker. SelenoF might play a role in assessing and refining the disulfide bonds of misfolded glycoproteins in the hydrophobic cavity of HUGT1 as it binds to the highly flexible region of HUGT1 to reach its long hydrophobic cavity. Clarification of the SelenoF-binding domain of UGGT and its relative position will help predict and reveal the function of SelenoF from a structural perspective.     

Numerical study of the correlation between fish school arrangement and propulsive performance

Artificial Life and Robotics - We focus on the distances in flow direction and its vertical direction on three fish school arrangements, and correlate the fish school in uniform flow with fluid...