Performance improvement of geographically distributed cosimulationby hierarchically grouped messages

To improve the performance of geographically distributed cosimulation, we propose a concept called hierarchically grouped message. The concept improves cosimulation performance, preserving the cosimulation accuracy, by hierarchically grouping messages transferred between simulators in a short period of simulated time into a single physical message, thereby reducing the number of physical messages. Applying the concept to hybrid and optimistic cosimulation, we can reduce the number of rollbacks as well as the communication overhead accompanying the message transfer. Experimental results show the efficiency of the proposed method for practical examples in an internationally distributed cosimulation environment     

Selenolthiol and dithiol C-terminal tetrapeptide motifs for one-step purification and labeling of recombinant proteins produced in E. coli

We have previously shown that a redox-active selenocysteine-containing tetrapeptide-Sel-tag (Gly-Cys-Sec-Gly)-can be used as a C-terminal fusion motif for recombinant proteins produced in Escherichia coli. This Sel-tag allows selenolate-targeted one-step purification, as well as fluorescent labeling or radiolabeling either with gamma emitters (75Se) or with positron-emitting radionuclides (11C). Here we have analyzed four different redox-active C-terminal motifs, carrying either dithiol (Gly-Cys-Cys-Gly or Ser-Cys-Cys-Ser) or selenolthiol (Gly-Cys-Sec-Gly or Ser-Cys-Sec-Ser) motifs. Utilizing these different functional motifs with the same recombinant protein (Fel d 1), we were able to assess their relative reactivities and potential usefulness for biotechnological applications. We found that all four redox-active tags could be utilized for efficient one-step purification to provide pure protein from a crude bacterial lysate through reversible binding to phenylarsine oxide sepharose, with yields and purities comparable to those obtained for a His-tagged protein purified by the more common approach with use of a Ni2+ column. For labeling with electrophilic fluorescent or radioactive compounds, however, the selenolthiol motifs were considerably more efficient than their dithiol counterparts. The results thus show that both the selenolthiol- and the dithiol-containing tags can serve as efficient alternatives to His-tags for protein purification, while the selenolthiol motifs offer additional and unique potential for Sec-targeted labeling. It should therefore be possible to utilize these multifunctional tetrapeptide motifs to develop a wide range of novel biotechnological applications based on Sec targeting with electrophilic compounds.     

Pilot-scale evaluation of the application of low pH-inducible polyphosphate accumulation to the biological removal of phosphate from wastewaters

To investigate the possible biotechnological application of the phenomenon of low pH-inducible phosphate uptake and polyphosphate accumulation, previously reported using pure microbial cultures and under laboratory conditions, a 2000 L activated sludge pilot plant was constructed at a municipal sewage treatment works. When operated as a single-stage reactor this removed more than 60% of influent phosphate from primary settled sewage at a pH of 6.0, as opposed to approximately 30% at the typical operational pH for the works of 7.0-7.3-yet without any deleterious effect on other treatment parameters. At these pH values the phosphorus content of the sludge was, respectively, 4.2% and 2.0%. At pH 6.0 some 33.9% of sludge microbial cells were observed to contain polyphosphate inclusions; the corresponding value at pH 7.0 was 18.7%. Such a process may serve as a prototype for the development of alternative biological and chemical options for phosphate removal from wastewaters.     

Beyond the Flatline

High Post-Modernism with its understanding of the significance of the image anticipated the flattening of culture, first in advertising and the printed media, and more recently online. Sam Jacob of FAT speculates on architecture's relationship with the Internet, ‘a flatland of undifferentiated information’, and how Radical Post-Modernism might be best placed to resist the ubiquity of global culture while reanimating the social and cultural agenda of Modernism and Post-Modernism. Copyright © 2011 John Wiley & Sons, Ltd.     

Shape matters: intravital microscopy reveals surprising geometrical dependence for nanoparticles in tumor models of extravasation

Delivery is one of the most critical obstacles confronting nanoparticle use in cancer diagnosis and therapy. For most oncological applications, nanoparticles must extravasate in order to reach tumor cells and perform their designated task. However, little understanding exists regarding the effect of nanoparticle shape on extravasation. Herein we use real-time intravital microscopic imaging to meticulously examine how two different nanoparticles behave across three different murine tumor models. The study quantitatively demonstrates that high-aspect ratio single-walled carbon nanotubes (SWNTs) display extravasational behavior surprisingly different from, and counterintuitive to, spherical nanoparticles although the nanoparticles have similar surface coatings, area, and charge. This work quantitatively indicates that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous.     

Silicon/Silicon Carbide Composites Fabricated by Infiltration of a Silicon Melt into Charcoal

Dense Si/SiC composites were fabricated via a conventional reaction-bonding process, using oak charcoal that exhibited a honeycomb structure. The silicon melt was infiltrated into the porous oak charcoal (density of ~0.6 g/cm³) while the sample was heated to 1700°C under vacuum (10^-3 torr (~0.133 Pa)), which resulted in in situ silicon-fiber/SiC composites. The reaction product had an average density of 2.8 g/cm³ and showed three-point flexural strengths of 330 MPa at room temperature and 280 MPa at 1300°C. Good oxidation resistance also was observed at temperatures up to 1300°C in flowing air. This process provided excellent shape-making capability, because the charcoal that was used as a preform was readily machinable.