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Using the "firm" quotes obtained from the tick-by-tick EBS (electronic broking system that is a major trading platform for foreign exchanges) data, it is found that risk-free arbitrage opportunities--free lunch--do occur in the foreign exchange markets, but it typically last only a few seconds. "Free lunch" is in the form of (a) negative spreads in a currency pair and (b) triangular arbitrage relationship involving three currency pairs. The latter occur much more often than the former. Such arbitrage opportunities tend to occur when the markets are active and volatile. Over the 12-year, tick-data samples, the number of free lunch opportunities has dramatically declined and the probability of the opportunities disappearing within one second has steadily increased. The size of expected profits is higher than transaction costs; trades that simultaneously take place on both sides of ask and bid (or three currency trades in case of triangular arbitrage) occur more often when free lunch appeared one second earlier than otherwise, suggesting that free lunch opportunities are actively taken. The probability of its disappearance within one second was less than 50% in 1999, but increased to about 90% by 2009. Less frequent occurrence and quicker disappearance in recent years are attributable to changes in trading microstructure: an introduction and proliferation of the Primary Customer system (weaker banks can use stronger banks' credit lines) and of direct connection of traders' programmed computers to the EBS computer.

Ground-state vibrational analyses of firefly luciferin and its conjugate acids and bases are performed. The Gibbs free energies obtained from these analyses are used to estimate pKa values for phenolic hydroxy and carboxy groups and the N-H(+) bond in the N-protonated thiazoline or benzothiazole ring of firefly luciferin. The theoretical pKa values are corrected using the experimental values. The concentrations of these chemical species in solutions with different pH values are estimated from their corrected pKa values, and the pH dependence of their relative absorption intensities is elucidated. With the results obtained we assign the experimental spectra unequivocally. Especially, the small peak near 400 nm at pH 1-2 in experimental absorption spectra is clarified to be due to the excitation of carboxylate anion with N-protonated thiazoline ring of firefly luciferin. Our results show that the pKa values of chemical species, which are contained in the aqueous solutions, are effective to assign experimental absorption spectra.

We present a new method that produces a variationally determined zeroth-order wave function for the analysis of intramolecular interactions between the fragments of a molecule. In our method, called the space-restricted wave function (SRW) method, this wave function is defined with nonorthogonal orbitals, which are obtained using the appropriately restricted variational spaces. The wave function thus obtained represents the electronic state with the target interactions deactivated, and it is constructed without unnecessarily breaking bonds, in contrast to some of the existing methods. Furthermore, we can perform energy decomposition analysis of intramolecular interactions using the zeroth-order functions that the SRW method yields. The validity of the SRW method is demonstrated in the analysis of the resonance energy and the rotational barrier of the C–N bond in formamide and its analogs. This method gives energy components that are different from those given by existing methods. With these components, we elucidate the origin of the rotational barrier from another point of view. Our SRW method gives meaningful results for the investigation of electron behavior and the nature of the molecular system.

The absorption and fluorescence spectra of firefly luciferin, which is an analog of oxyluciferin, are investigated by performing the density functional theory (DFT) calculations, especially focusing on the experimentally unassigned peaks. Time-dependent DFT calculations are performed for the excited states of firefly luciferin and its conjugate acids and bases. We find that (1) the peaks in the experimental absorption spectra correspond to the excited states of not only (6'O(-), 4COO(-)) and (6'OH, 4COO(-)), but also (6'OH, 4COOH) and (6'OH, 3H(+), 4COOH); (2) the peaks in the experimental fluorescence spectra correspond to the excited states of not only (6'O(-), 4COO(-)), but also (6'OH, 4COO(-)), (6'O(-), 4COOH), (6'OH, 4COOH) and (6'OH, 3H(+), 4COOH); (3) the unassigned peak near 400 nm in the experimental absorption spectra at pH 1 is assigned to the absorption from the equilibrium ground state to the first excited state of (6'OH, 3H(+), 4COOH); and (4) the unassigned peak at 610 nm in the experimental fluorescence spectra corresponds to the transition from the equilibrium first excited state to the ground state of (6'OH, 4COO(-)).

We have developed a space-restricted wave function (SRW) method for the analysis of various types of intramolecular interactions. In this study, we demonstrate the applicability of our SRW method to the analysis of the nature of the P-O bond in phosphine oxide (R(3)PO), one of the hypervalent molecules. An interesting character of this bond has been extensively studied by focusing on the negative hyperconjugation of the O lone pair (n(O)) with the R(3)P group. We reinvestigated the nature of the bond in terms of a change in total energy to produce evidence for the validity of our method. The electronic states without the interaction involving three n(O) orbitals (R(3)P(+)-O(-)) produced by the method were used as reference states in the assessment of the effects of this n(O)-R(3)P interaction. The result confirms that this interaction plays an essential role in the nature of the bond and occurs between the n(O) orbitals and the P-R antibonding orbitals, in agreement with previous studies. A molecular orbital (MO)-pair analysis technique shows that the n(O)-R(3) P interaction is decomposed into the negative hyperconjugation and the Pauli repulsion. Considering a reference state where the P-O bond is completely broken (R(3)P(2+) · · ·O(2-)) at an interacting distance, P-O bond formation is attributed to one σ bond plus two 0.5 π bonds. This is equivalent to three banana bonds highly polarized to the O atom. Consequently, the SRW method suggested improved explanations of the nature of the P-O bond.

Protein dynamics of isolated chains of recombinant human adult hemoglobin (rHb) following ligand photolysis were studied by time-resolved resonance Raman spectroscopy. In the time-resolved spectra, we observed frequency shifts of the iron-histidine stretching [ν(Fe-His)] and γ(7) bands and an intensity change of the ν(8) band for both the isolated α- and β-chains, showing that a primary metastable form was present in the initial tens of nanoseconds following the photolysis. Similar spectral changes were reported for human adult hemoglobin and rHb. Common spectral changes between isolated chains and hemoglobin indicated that structural changes reflected by the spectral changes were characteristic of the hemoglobin subunits. The heme modes suggested that the primary metastable form had a more disordered orientation of propionates and a less strained environment than the deoxy form. The spectral changes of the isolated α-chain were faster than those of the β-chain. In spite of the fact that the isolated β-chain formed a tetramer in a similar fashion to rHb, the spectral changes were much slower than those of rHb. The present study shows that intersubunit interactions affected the rates of the structural changes of the heme pocket. Characteristics of the tertiary structure dynamics of hemoglobin are discussed.

Retinal pigment epithelial (RPE) cells were cultured on the laminin-coated and plain surfaces. The measurement of local nucleus density in non-stratified region, which correlated with formation of tight junction, is the indicator of the maturation, and the parameters can be applied to the evaluation of the early-stage maturation of RPE cells in culture.

Cell signaling mediated by the Notch receptor (N) regulates many cell-fate decisions and is partly controlled by the endocytic trafficking of N. Drosophila deltex (dx) encodes an evolutionarily conserved regulator of N signaling, an E3-ubiquitin ligase, which ubiquitinates N's intracellular domain. Although Dx was shown to function in N endocytosis in studies of dx over-expression, the roles of endogenous Dx have remained hidden. Here, we investigated N endocytosis in a dx-null Drosophila mutant and found that endogenous Dx is required for at least two steps of N trafficking: the incorporation of N into endocytic vesicles from the plasma membrane and the transport of N from early endosomes to lysosomes. In the absence of Dx functions, N was stabilized in unknown endocytic compartments, where it was probably insulated from transport to lysosomes. We also found that canonical N signaling and Dx-mediated N signaling are activated in two different endocytic compartments, before N is incorporated into multivesicular body (MVB) interluminal vesicles and after N is transported from MVBs, respectively. The endocytic compartment in which Dx-mediated N signaling is activated appears to coincide with the activity of endogenous Dx in N trafficking. These findings extend our understanding of how N's trafficking and activation are correlated.

We present an alternative approach to determine "density-dependent property"-derived charges for molecules in the condensed phase. In the case of a solution, it is essential to take into consideration the electron polarization of molecules in the active site of this system. The solute and solvent molecules in this site have to be described by a quantum mechanical technique and the others are allowed to be treated by a molecular mechanical method (QM/MM scheme). For calculations based on this scheme, using the forces and interaction energy as density-dependent property our charges from interaction energy and forces (CHIEF) approach can provide the atom-centered charges on the solute atoms. These charges reproduce well the electrostatic potentials around the solvent molecules and present properly the picture of the electron density of the QM subsystem in the solution system. Thus, the CHIEF charges can be considered as the atomic charges under the conditions of the QM/MM simulation, and then enable one to analyze electrostatic interactions between atoms in the QM and MM regions. This approach would give a view of the QM nuclei and electrons different from the conventional methods.

Accurate and useful compact models of parasitic resistance of resistors for analog circuits are proposed. The model is applicable to any layout patterns and topologies normally used in analog circuits. In addition, test structures to measure the parasitic resistance correctly are shown and the models are validated for a 40nm CMOS technology.

Ad hoc on-demand distance vector (AODV) routing protocol has been investigated for mobile ad hoc networks and more commonly used. However, if there are unidirectional links in the networks, significantly long latency may be required for a route establishment when AODV routing protocol is used. We assume that unidirectional links can be occurred due to a difference of transmission power between the communicating nodes. Bidirectional routing abstraction (BRA) has been proposed to solve the problem of unidirectional link by using multi-hop broadcast technique. In addition, BRA has a potential to reduce the latency of route establishment in asymmetric networks. However multi-hop broadcast technique leads to an redundant power consumption. This paper proposes a routing protocol, which is AODV with cooperative relaying technique (CR-AODV). The cooperative relaying technique can extend the coverage and solve the problem of unidirectional links with less power consumption and less latency compared with BRA. By computer simulations, we show that our proposed method can reduce power consumption compared to BRA in a route establishment.

The photo-transformed products of fenthion well-known as one of the most photosensitive organophosphorus insecticides and their estrogenic activities were investigated using a yeast two-hybrid assay incorporating the human estrogen receptor alpha (hERalpha). We identified fenthion sulfoxide and 3-methyl-4-methylsulfinylphenol (MMS) as the major transformed products and 3-methyl-4-(methylthio)phenol (MMP) as the minor product under UV-A irradiation. Further, significant estrogenic activity was observed in the solution irradiated for 160 min; this activity was evaluated as 18 pM converted to 17beta-estradiol (E(2)) equivalent concentration. By using authentic standards, it was found that MMP possessed weak estrogenic activity; its activity was evaluated as 1.7x10(-6) times compared with that of E(2). However, it was also revealed that the activity due to MMP was only 13%. From high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopies, we newly identified a significant estrogenic compound transformed from fenthion, O,O-dimethyl S-[3-methyl-4-(methylthio)phenyl]phosphorothioate, S-aryl fenthion.

We apply the potential force estimation method to artificial time series of market price produced by a deterministic dealer model. We find that dealers' feedback of linear prediction of market price based on the latest mean price changes plays the central role in the market's potential force. When markets are dominated by dealers with positive feedback the resulting potential force is repulsive, while the effect of negative feedback enhances the attractive potential force., 9 pages, 3 figures, proceedings of APFA6

We focus on Internet rumors and present an empirical analysis and simulation results of their diffusion and convergence during emergencies. In particular, we study one rumor that appeared in the immediate aftermath of the Great East Japan Earthquake on March 11, 2011, which later turned out to be misinformation. By investigating whole Japanese tweets that were sent one week after the quake, we show that one correction tweet, which originated from a city hall account, diffused enormously. We also demonstrate a stochastic agent-based model, which is inspired by contagion model of epidemics SIR, can reproduce observed rumor dynamics. Our model can estimate the rumor infection rate as well as the number of people who still believe in the rumor that cannot be observed directly. For applications, rumor diffusion sizes can be estimated in various scenarios by combining our model with the real data.

A novel interconnect design concept named "ASIS (application-specific interconnect structure)" is presented for 45 nm CMOS performance maximization. Basic scheme of ASIS is that corresponding to applications, such as high-performance, low-power or high reliability, interconnect structure as well as metal thickness is individually optimized in order to maximize chip-level performance matched to the application. Our investigation shows that for low power application, the increased resistivity of scaled-down Cu-wire is not a main issue, so that thinner wire is more advantageous. For high-performance application, partially double pitch structure for local and intermediate layers is advantageous. For high-reliability requirement, CuAl-alloy or CoWP cap-metal is quite effective for boosting reliability

We introduce a deterministic dealer model which implements most of the empirical laws, such as fat tails in the price change distributions, long term memory of volatility and non-Poissonian intervals. We also clarify the causality between microscopic dealers' dynamics and macroscopic market's empirical laws., Comment: 10pages, 5figures, 1table, Proceedings of APFA5

This paper newly proposes an accurate modeling method of the copper interconnect cross-section in which the width and thickness dependence on layout patterns and density are fully incorporated and universally expressed. In addition, we have developed specific test patterns for the model parameters extraction, and an efficient extraction flow which features correlating cross-section observation and resistance measurement to obtain the parameter values. We have extracted the model parameters for 0.15 /spl mu/m CMOS using this method and confirmed that 10% /spl tau/pd error normally observed with conventional LPE (Layout Parameters Extraction) was completely dissolved. This is the first time that the practical and accurate modeling methodology for layout pattern sensitive Cu Interconnect is ever reported.

A robust embedded ladder-oxide (k=2.9)/Cu multilevel interconnect is demonstrated for the 0.13 /spl mu/m CMOS generation. A stable ladder-oxide IMD is integrated into the Cu metallization with minimum wiring pitch of 0.34 /spl mu/m, and a single damascene (S/D) Cu-plug structure is applied. An 18% reduction in wiring capacitance is obtained compared with SiO/sub 2/ IMD. The stress-migration lifetime of vias on wide metals for S/D Cu-plug structure is much longer than for dual damascene (D/D). The reliability test results such as those for electromigration (EM), Cu interconnect TDDB, and pressure cooker test (PCT) are quite acceptable. Moreover, high flexibility in thermal design and packaging is obtained.

Innate immunity is generally initiated with recognition of conserved pathogen-associated molecular patterns (PAMPs). PAMPs are perceived by pattern recognition receptors (PRRs), leading to activation of a series of immune responses, including the expression of defense genes, ROS production and activation of MAP kinase. Recent progress has indicated that receptor-like cytoplasmic kinases (RLCKs) are directly activated by ligand- activated PRRs and initiate pattern -triggered immunity (PTI) in both Arabidopsis and rice. To suppress PTI, pathogens inhibit the RLCKs by many types of effectors, including AvrAC, AvrPphB and Xoo1488. In this review, we summarize recent advances in RLCK-mediated PTI in plants.

We investigated the runoff properties of SS, TN, and TP in the Mimitori River and the Takizawa River streaming in agricultural areas in Iwate prefecture, Japan. Field observations provide that the following findings: 1) the concentrations of SS, TN, and TP increase in paddling and transplanting period in paddy fields, 2) TN and TP concentrations strongly correlate with SS, 3) the loads of SS and nutrients are much higher during rainfall time. To examine the possibility to control SS sorbing nutrients, we carried out experimental studies on the charging and flocculation of the suspended particles as well as the resuspension of flocculated sediments. The results clarified that the flocculation behaviors qualitatively follow the DLVO theory and the resuspension behaviors are similar to those of natural sediments. Finally, we suggest that increasing calcium ions over 2mM is effective to settle down the particles.

We numerically analyze an artificial market model consisted of N dealers with time dependent stochastic strategy. Observing the change of market price statistics for different values of N, it is shown that the statistical properties are almost same when the dealer number is larger than about 30.

Probing with a tip of scanning tunneling microscopy (STM) of metallic single-walled carbon nanotubes (SWCNT) was found to induce defects in the tubes. The primary defect formation by probing was enhanced with a rate proportional to tunnel-injected electron current above a sample-bias threshold of around +4 V. Scanning tunneling spectroscopic measurements of local density of states revealed that the defects imaged by STM, presumably secondary defects stabilized at the test temperature (95 K), are accompanied by a localized bandgap of 0.7 eV, which may account for the reported metal-semiconductor conversion in SWCNT-based field-effect transistor that is induced by low-energy electron irradiation.

SummaryCERK1 is a lysine motif-containing plant pattern recognition receptor for chitin and peptidoglycan. Chitin recognition by OsCERK1 triggers rapid engagement of a rice MAP kinase cascade, which leads to defense response activation. How the MAP kinase cascades are engaged downstream of OsCERK1 remains obscure. Searching for host proteins that interact with Xoo1488, an effector of the rice pathogen Xanthomonas oryzae, we identified the rice receptor-like cytoplasmic kinase, OsRLCK185. Silencing OsRLCK185 suppressed peptidoglycan- and chitin-induced immune responses, including MAP kinase activation and defense-gene expression. In response to chitin, OsRLCK185 associates with, and is directly phosphorylated by, OsCERK1 at the plasma membrane. Xoo1488 inhibits peptidoglycan- and chitin-induced immunity and pathogen resistance. Additionally, OsCERK1-mediated phosphorylation of OsRLCK185 is suppressed by Xoo1488, resulting in the inhibition of chitin-induced MAP kinase activation. These data support a role for OsRLCK185 as an essential immediate downstream signaling partner of OsCERK1 in mediating chitin- and peptidoglycan-induced plant immunity.

Nitric oxide (NO) plays diverse and significant roles in biological processes despite its cytotoxicity, raising the question of how biological systems control the action of NO to minimize its cytotoxicity in cells. As a great example of such a system, we found a possibility that NO-generating nitrite reductase (NiR) forms a complex with NO-decomposing membrane-integrated NO reductase (NOR) to efficiently capture NO immediately after its production by NiR in anaerobic nitrate respiration called denitrification. The 3.2-A resolution structure of the complex of one NiR functional homodimer and two NOR molecules provides an idea of how these enzymes interact in cells, while the structure may not reflect the one in cells due to the membrane topology. Subsequent all-atom molecular dynamics (MD) simulations of the enzyme complex model in a membrane and structure-guided mutagenesis suggested that a few interenzyme salt bridges and coulombic interactions of NiR with the membrane could stabilize the complex of one NiR homodimer and one NOR molecule and contribute to rapid NO decomposition in cells. The MD trajectories of the NO diffusion in the NiR:NOR complex with the membrane showed that, as a plausible NO transfer mechanism, NO released from NiR rapidly migrates into the membrane, then binds to NOR. These results help us understand the mechanism of the cellular control of the action of cytotoxic NO.