Black Holes in Two Dimensional Dilaton Gravity and Nonlinear Klein-Gordon Soliton

Two-dimensional dilaton gravity coupled to a Klein-Gordon matter field with a quartic interaction term is considered. The theory has a classical solution which exhibits black hole formation by a soliton. The geometry of black hole induced by a soliton is investigated.Comment: 9 pages, no figures, late

High-Throughput Screening of Acyl-CoA Thioesterase I Mutants Using a Fluid Array Platform

Screening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified Escherichia coli ???TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (106) mutant library. A growth-based screening method using a TetA-RFP fusion sensing mechanism and a reporter-based screening method using high-level FFA producing mutants were employed to identify these mutants via HTS. The platform was able to cover >95% of the mutation library, and it screened target cells from many arrays of the fluid array platform so that a post-analysis could be conducted by gas chromatography. The ???TesA mutation of each isolated mutant showing improved FFA production in E. coli was characterized, and its enhanced FFA production capability was confirmed

Silicon improves growth and antioxidative defense system in salt-stressed Kentucky bluegrass (Poa pratensis L.), ‘Perfection’ and ‘Midnight’

After 400 mM of NaCl treatment, 0.1 and 1.0 mM of silicon (Si) were added to Kentucky bluegrass, ‘Perfection’ and ‘Midnight,’ to identify the effect of Si on the antioxidant defense mechanisms and inorganic ions as a parameter in the salt stress on grass. Compared to the control, the NaCl treatment caused a significant decrease in the shoot length and the fresh and dry weight of shoot and root of the both types of Kentucky bluegrass. Adding Si after the NaCl treatment increased the growth and dry and fresh weight of shoot and root in the grass. In both types, the Na+ concentration significantly increased after the NaCl-only treatment compared to control and decreased dramatically after 0.1 and 1.0 mM Si were added following the NaCl treatment compared to the NaCl-only treatment. K+ and Si concentrations remarkably increased in the shoot and root when Si was added after NaCl treatment. There was a significant reduction in the oxygen radical absorption capacity and the total phenolic compounds in the both types. Compared to the NaCl-only treatment, higher glutathione and lower proline concentrations were observed in the plant treated with Si after NaCl treatment. These results suggest that, even though Si is not generally classified as ‘essential element’, Si may have a significant involvement in the antioxidant defense mechanisms and inorganic ions in the salt stress on grass.Key words: diphenyl-1-picrylhydrazyl (DPPH), total phenolic concentration, proline, salt stress

A KINEMATIC ANALYSIS OF ELDERLY GAIT WHILE STEPPING OVER OBSTACLES OF VARYING HEIGHT

The purpose of this study was to investigate the kinematics of elderly people who had experienced a fall stepping over obstacles of varying height. Six elderly non-fallers and six elderly fallers stepped over obstacles of height 0, 2.5, 5.1, 15.2cm. The longest stance duration was found in the highest obstacle 15.2cm, which might reflect relatively fast degrading gait function of the faller group. It was found that fallers took a longer time to cross the obstacles, which resulted in slower crossing speeds than when non-fallers stepped over the obstacles. We concluded that elderly persons who had experienced falling tend to step over obstacles conservatively as characterized