The DNA sequences of wheat Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, were analyzed with a view to understanding the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Acc-1 and Acc-2 loci from each of the wheats Triticum urartu (A genome), Aegilops tauschii (D genome), Triticum turgidum (AB genome), and Triticum aestivum (ABD genome), as well as two Acc-2-related pseudogenes from T. urartu were sequenced. The 2.3-2.4 Mya divergence time calculated here for the three homoeologous chromosomes, on the basis of coding and intron sequences of the Acc-1 genes, is at the low end of other estimates. Our clock was calibrated by using 60 Mya for the divergence between wheat and maize. On the same time scale, wheat and barley diverged 11.6 Mya, based on sequences of Acc and other genes. The regions flanking the Acc genes are not conserved among the A, B, and D genomes. They are conserved when comparing homoeologous genomes of diploid, tetraploid, and hexaploid wheats. Substitution rates in intergenic regions consisting primarily of repetitive sequences vary substantially along the loci and on average are 3.5-fold higher than the Acc intron substitution rates. The composition of the Acc homoeoloci suggests haplotype divergence exceeding in some cases 0.5 Mya. Such variation might result in a significant overestimate of the time since tetraploid wheat formation, which occurred no more than 0.5 Mya.acetyl-CoA carboxylase ͉ Triticeae ͉ grass

We study the traffic flow on a highway with ramps through numerical simulations of a hydrodynamic traffic flow model. It is found that the presence of the external vehicle flux through ramps generates a new state of recurring humps (RH). This novel dynamic state is characterized by temporal oscillations of the vehicle density and velocity which are localized near ramps, and found to be the origin of the synchronized traffic flow reported recently [PRL 79, 4030 (1997)]. We also argue that the dynamic phase transitions between the free flow and the RH state can be interpreted as a subcritical Hopf bifurcation.PACS numbers: 89.40.+k, 64.60.Cn, 05.40.+j Experiences show that traffic flow has complicated properties. The fact that automobile is one of main transportation tools raises the traffic flow as one of the most important problems for engineers [1]. For physicists, on the other hand, traffic flow is an interesting many-body problem of interacting vehicles. Numerous experimental measurements revealed that traffic flow possesses qualitatively distinct dynamic states [2]. In particular, three distinct dynamic phases are observed in highways [3]: the free traffic flow which is analogous to laminar flow in fluid systems, the traffic jam state where vehicles almost do not move, and the synchronized traffic flow which is characterized by complicated temporal variations of the vehicle density and velocity.Paralleled with experiments, many physical models have been proposed [4]. Cellular automaton models [5] have been developed which simulate each individual vehicle, and hydrodynamic models [6,7] which provide macroscopic description of traffic flow. Subsequent studies [8,9] of the models have explained many observed features of the free flow and traffic jams in highways. However, no satisfactory explanation for the synchronized flow is available to our knowledge.Recently, Kerner and Rehborn reported analysis of systematic measurements performed on German highways. As one of main results, it was pointed out that the synchronized flow is spatially localized near ramps on highways [10]. This observation motivated us to explore in this paper effects of ramps on highway traffic flow. Through numerical simulations of a hydrodynamic model, we find that the presence of ramps generates a new kind of traffic states which becomes a spatially localized limit cycle of highway traffic flow under the constant external flux. We examine properties of the novel state and show that it is the origin of the synchronized flow.In this work, we adopt the hydrodynamic model of highway traffic flow proposed by Kerner and Konhäuser [6], where the dynamic evolution is described by the Navier-Stokes-type equation of motion,Here ρ(x, t) is the local vehicle density, v(x, t) the local velocity, V (ρ) the safe velocity that is achieved in the time-independent and homogeneous traffic flow, and τ, c 0 , µ are appropriate constants. Eq. (1) is paired with the modified equation of continuity [11],where the source and the drain terms on the right hand ...

We study the phase diagram of the continuum traffic flow model of a highway with an on-ramp. Using an open boundary condition, traffic states and metastabilities are investigated numerically for several representative values of the upstream boundary flux f(up) and for the whole range of the on-ramp flux f(rmp). An inhomogeneous but time-independent traffic state (standing localized cluster state) is found and related to a recently measured traffic state. Due to the density gradient near the on-ramp, a traffic jam can occur even when the downstream density is below the critical density of the usual traffic jam formation in homogeneous highways, and its structure varies qualitatively with f(rmp). The free flow, the recurring hump (RH) state, and the traffic jam can all coexist in a certain metastable region where the free flow can undergo phase transitions either to the RH state or to the traffic jam state. We also find two nontrivial analytic solutions. These solutions correspond to the standing localized cluster state and the homogeneous congested traffic state (one form of the traffic jam), which are observed in numerical simulations.

SummaryBackground Allergic rhinitis (AR) is a very common disease and a risk factor for allergic asthma. The discovery of new biomarkers for the early detection of AR would improve the clinical outcomes and reduce socio-economic burden. We sought to identify a novel serologic marker for detection of AR using a proteomic approach. Methods To identify the proteins involved in AR, comparative proteomics was applied using nasal lavage fluids (NLFs) taken before and after a nasal provocation test (NPT) with Dermatophagoides pteronyssinus (Dpt) in a subject with AR sensitized to Dpt. The clinical relevance of the identified proteins was evaluated by ELISA using NLFs and sera from the three study groups: Dpt-sensitive AR; asymptomatic Dpt-sensitive controls; and non-atopic healthy controls. The sensitivities and specificities of the candidate proteins for predicting AR were determined using receiver operating characteristic (ROC) curves. Results In proteomic analysis, lactoferrin expression was up-regulated after NPT. The validation study using ELISA showed a significantly lower serum lactoferrin level in the AR group than those of the other two groups (Po0.05, respectively). To discriminate between subjects with or without AR, the optimal serum cut-off level of lactoferrin was set at o307 ng/mL using the ROC curve. The sensitivity and specificity for predicting AR were 81.4% and 58%. When combined with serum Dpt-specific IgE level, the sensitivity and specificity for predicting AR were 76.7% and 79.2%. Conclusion These results suggest that the serum lactoferrin level is associated with the phenotype of Dpt-sensitive AR, and in combination with the serum Dpt-specific IgE level, may be a potential serologic marker for early detection of AR.

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