Fate of coliphage in a wastewater treatment process

The fate of coliphage in a wastewater treatment plant in the central part of Japan was investigated from March to December 2001. A relative abundance of coliphage, 1000-10,000 PFU/ml determined with three different Escherichia coli strains, was detected in the influent. But, no remarkable seasonal change in the phage concentration in the influent was observed during the ten-month test period. Almost ten times higher coliphage concentration was detected by the F+ E. coli strain than by the other two F- strains. The RNA phage was more stable than the DNA phage against aerobic treatment using activated sludge. Most of the phages in the influent and primary settling tank were detected as suspended forms. Anaerobic-aerobic treatment enhanced adsorption of the phage by the solid particles. Almost no phage was detected in the effluent. Aerobic treatment using activated sludge and/or the addition of flocculants such as PAC was effective for the removal of coliphage, an index of enteric viral pollution.     

Gene expression property of high-density three-dimensional tissue of HepG2 cells formed in radial-flow bioreactor

In our previous study, we examined three-dimensional culture using 5-ml radial-flow bioreactor (RFB) and showed that genes encoding cell cycle related proteins were suppressed in a stable phase. In this study, we analyzed the gene expression profiles of RFB-cultivated HepG2 cells and found that vascular endothelial growth factor (VEGF) production was strongly induced in the stable phase compared with the growth phase or static two-dimensional culture. When human umbilical vein endothelial cells (HUVECs) were grown under the conditioned medium of the stable phase, it was found that the formation of new blood vessels was induced in the angiogenesis model. DNA microarray analysis showed that the expression levels of both genes related to cell cycle arrest and which are known as tumor markers have increased in the stable phase. This result suggests that HepG2 cells in the stable phase maintain an active tumor phenotype. In addition, the expression of genes induced in the hypoxic condition was also induced in the stable phase. When the culture was carried out under a higher dissolved oxygen (DO) concentration, VEGF production did not decrease significantly and the new blood-vessel-forming ability of the conditioned medium was not suppressed. This suggests that the induction of VEGF production in a stable phase is not affected by DO during the tested level. These results suggest that the RFB cell culture system may be used to assess tumor progression mechanism under three-dimensional condition in vitro.     

Training effect on damping capacity in Fe–20 mass% Mn binary alloy

Two-dimensional finite element analysis together with stream function and neural network models are employed to determine thermo-mechanical behavior during hot strip rolling of AA5083. An appropriate velocity field and stream function is first determined using the rule of volume constancy and upper bound theorem and then temperature field within the metal is predicted by means of a two-dimensional conduction–convection model. In order to consider the effect of flow stress and its dependence on temperature, strain and strain rate, a neural network model is also employed in the analysis. Based on the performed tensile tests, two different neural network models are constructed one for smooth yielding and the other one for the serrated flow. Then, the ANN models are coupled with the thermo-mechanical analysis. In the next step, by combination of the predicted temperature, strain and strain rates fields and the experimental data achieved from the tensile tests, the occurence of dynamic strain ageing during hot rolling is predicted. The model predictions are then compared with the experimental data and good agreement is observed between the two sets of results that shows the validity of the proposed model.     

P(BS-co-DGA)共聚物的合成和降解性的研究

改变二乙醇酸(DCA)的添加量和聚丁二酸丁二醇酯PBS缩合聚合,得到了数均分子质量达6.5万以上的P(BS-co-DGA)二元无规共聚物.使用核磁共振表征了共聚物的化学结构,根据不同DGA的添加量对共聚物的相对分子质量、热性质、力学性能、降解性的影响等进行了研究.结果表明P(BS-co-DGA)共聚物在较短的反应时间内具有相对高的数均分子质量,分子量分布在2左右;随着DGA添加量的增加,共聚物的Tm和△Hm呈降低趋势;但是所有共聚物的热稳定性没有大的改变,热分解温度均在300℃以上;DGA添加量为2%时在堆肥中的降解速度最快.     

Soft-computing-based emotional expression mechanism for game of computer Go

The game of Go is considered one of the most complicated games in the world. One Go game is divided into three stages: the opening, the middle, and the ending stages. Millions of people regularly play Go in countries around the world. The game is played by two players. One is White and another is Black. The players alternate placing one of their stones on an empty intersection of a square grid-patterned game board. The player with more territory wins the game. This paper proposes a soft-computing-based emotional expression mechanism and applies it to the game of computer Go to make Go beginners enjoy watching Go game and keep their tension on the game. First, the knowledge base and rule base of the proposed mechanism are defined by following the standards of the fuzzy markup language. The soft-computing mechanism for Go regional alarm level is responsible for showing the inferred regional alarm level to Go beginners. Based on the inferred board situation, the fuzzy inference mechanisms for emotional pleasure and arousal are responsible for inferring the pleasure degree and arousal degree, respectively. An emotional expression mapping mechanism maps the inferred degree of pleasure and degree of arousal into the emotional expression of the eye robot. The protocol transmission mechanism finally sends the pre-defined protocol to the eye robot via universal serial bus interface to make the eye robot express its emotional motion. From the experimental results, it shows that the eye robot can support Go beginners to have fun and retain their tension while watching or playing a game of Go.     

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...