A Critical Examination to the Unitarized ππ\pi\pi Scattering Chiral Amplitudes

We discuss the Pad\'e approximation to the $\pi\pi$ scattering amplitudes in 1--loop chiral perturbation theory. The approximation restores unitarity and can reproduce the correct resonance poles, but the approximation violates crossing symmetry and produce spurious poles on the complex $s$ plane and therefore plagues its predictions on physical quantities at quantitative level. However we find that one virtual state in the IJ=20 channel may have physical relevance.Comment: 13 pages + 4 eps figures submit to Commun. Theor. Phy

Monofunctional Platinum-DNA Adducts Are Strong Inhibitors of Transcription and Substrates for Nucleotide Excision Repair in Live Mammalian Cells

To overcome drug resistance and reduce the side effects of cisplatin, a widely used antineoplastic agent, major efforts have been made to develop next generation platinum-based anticancer drugs. Because cisplatin–DNA adducts block RNA polymerase II unless removed by transcription-coupled excision repair, compounds that react similarly but elude repair are desirable. The monofunctional platinum agent pyriplatin displays antitumor activity in mice, a cytotoxicity profile in cell cultures distinct from that of cisplatin, and a unique in vitro transcription inhibition mechanism. In this study, we incorporated pyriplatin globally or site specifically into luciferase reporter vectors to examine its transcription inhibition profiles in live mammalian cells. Monofunctional pyriplatin reacted with plasmid DNA as efficiently as bifunctional cisplatin and inhibited transcription as strongly as cisplatin in various mammalian cells. Using repair-defective nucleotide excision repair (NER)-, mismatch repair-, and single-strand break repair–deficient cells, we show that NER is mainly responsible for removal of pyriplatin–DNA adducts. These findings reveal that the mechanism by which pyriplatin generates its antitumor activity is very similar to that of cisplatin, despite the chemically different nature of their DNA adducts, further supporting a role for monofunctional platinum anticancer agents in human cancer therapy. This information also provides support for the validity of the proposed mechanism of action of cisplatin and provides a rational basis for the design of more potent platinum anticancer drug candidates using a monofunctional DNA-damaging strategy.National Cancer Institute (U.S.) (Grant Number CA034992

Surface plasmon enhanced responsivity in a waveguided germanium metal-semiconductor-metal photodetector

The authors report on high transverse magnetic (TM)-mode responsivity in a waveguided germaniumSchottky-barriermetal-semiconductor-metalphotodetector on silicon-on-insulator substrate for operating wavelength at 1550 nm. The employed aluminum interdigitated electrodes act as a one-dimensional rectangular grating above the depletion layer. By means of properly designed finger dimensions, surface plasmon polariton resonances can be excited at the interface of metal and silicon interfacial layer due to grating coupling. The resulting strong field intensities reach into active region, enabling high absorption under TM injection. At a voltage of 1 V, the TM-mode photocurrent is measured over three times than that of transverse electric mode, in spite of the relatively larger TM insertion loss in the silicon waveguide.This work is supported by Agency for Science, Technology and Research A*STAR SERC Science and Engineering Research Council Grant Programme SERC Grant No. 092 154 0098, Singapore

Deciphering the genome structure and paleohistory of _Theobroma cacao_

We sequenced and assembled the genome of _Theobroma cacao_, an economically important tropical fruit tree crop that is the source of chocolate. The assembly corresponds to 76% of the estimated genome size and contains almost all previously described genes, with 82% of them anchored on the 10 _T. cacao_ chromosomes. Analysis of this sequence information highlighted specific expansion of some gene families during evolution, for example flavonoid-related genes. It also provides a major source of candidate genes for _T. cacao_ disease resistance and quality improvement. Based on the inferred paleohistory of the T. cacao genome, we propose an evolutionary scenario whereby the ten _T. cacao_ chromosomes were shaped from an ancestor through eleven chromosome fusions. The _T. cacao_ genome can be considered as a simple living relic of higher plant evolution

Integrating anticipative replenishment-allocation with reactive fulfillment for online retailing using robust optimization

Ministry of Education, Singapore under its Academic Research Funding Tier 1; Lee Kong Chian Fellowship; MPA Research Fellowshi

Feasibility and principle analyses of morphing airfoil used to control flight attitude

Morphing airfoil technology can enable an aircraft to adapt its shape to enhance mission performance and replace the traditional flap, ailerons, elevator and rudders to optimize flight attitude control efficiency. A set of optimal airfoil shapes are obtained aimed to minimize the aerodynamic drag character by optimizing morphing configurations at different under the two-dimensional steady-flow simulation. The traditional airfoil and morphing airfoil at different are compared. It is proved that morphing wing can be used instead of a traditional wing. Couples of traditional control surface and morphing airfoil are chosen to simulate and analyze the aerodynamic difference. The flow mechanism is described on the basis of aerodynamic simulations performed by CFX. It is demonstrated why the morphing wing can provide the same with a small