1,231 research outputs found

    Quasi-Solitons in Dissipative Systems and Exactly Solvable Lattice Models

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    A system of first-order differential-difference equations with time lag describes the formation of density waves, called as quasi-solitons for dissipative systems in this paper. For co-moving density waves, the system reduces to some exactly solvable lattice models. We construct a shock-wave solution as well as one-quasi-soliton solution, and argue that there are pseudo-conserved quantities which characterize the formation of the co-moving waves. The simplest non-trivial one is given to discuss the presence of a cascade phenomena in relaxation process toward the pattern formation.Comment: REVTeX, 4 pages, 1 figur

    Solvable Optimal Velocity Models and Asymptotic Trajectory

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    In the Optimal Velocity Model proposed as a new version of Car Following Model, it has been found that a congested flow is generated spontaneously from a homogeneous flow for a certain range of the traffic density. A well-established congested flow obtained in a numerical simulation shows a remarkable repetitive property such that the velocity of a vehicle evolves exactly in the same way as that of its preceding one except a time delay TT. This leads to a global pattern formation in time development of vehicles' motion, and gives rise to a closed trajectory on Δx\Delta x-vv (headway-velocity) plane connecting congested and free flow points. To obtain the closed trajectory analytically, we propose a new approach to the pattern formation, which makes it possible to reduce the coupled car following equations to a single difference-differential equation (Rondo equation). To demonstrate our approach, we employ a class of linear models which are exactly solvable. We also introduce the concept of ``asymptotic trajectory'' to determine TT and vBv_B (the backward velocity of the pattern), the global parameters associated with vehicles' collective motion in a congested flow, in terms of parameters such as the sensitivity aa, which appeared in the original coupled equations.Comment: 25 pages, 15 eps figures, LaTe

    Separate measurements of the flexoelectric and surface polarization in a model nematic liquid crystal p-methoxybenzylidene-p´-butylaniline : Validity of the quadrupolar approach

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    The temperature dependences of the surface polarization have been measured at the interface of a conductive glass with both the homogeneously and homeotropically oriented nematic liquid crystal p-methoxybenzylidene-p´-butylaniline. The polarization was found in the field-off regime from the pyroelectric response of a cell to a short laser pulse, absorbed in the bulk of the liquid crystal. The temperature increment was calculated from the measurements of the birefringence induced by the same light pulse. It has been shown that the surface polarization at the homeotropic (mh) and planar (mp) interfaces is directed from an interface into the bulk and from the bulk to an interface, respectively (with a magnitude mh~— 0.3 pC/m and mp' ≈ 0.2 pC/m at 25℃). The experimental data may be explained in terms of the quadrupole model of the order-electric polarization with account of some additional contribution from molecular dipoles. The same technique also allows for the measurements of the z component of the flexoelectric polarization using a pyroelectric response of a hybrid (homeoplanar) aligned nematic cell and proper subtracting of the surface contributions. The flexoelectric polarization has been shown to be opposite to the sum of the surface terms mh + mp and directed from the planar to homeotropic interface. This means that the sum of the flexoelectric coefficients e=(e1 + e3) is positive (e ≅ 1.7 pC/m at 28℃). The temperature dependence of e has been shown to involve a combination of both the quadrupolar and dipolar contributions

    Analysis of Patients Visiting Niigata University Medical and Dental Hospital with Chief Complaints of Metal Allergy And/or Focal Infection in the Previous 8 Years

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    Dental metal allergy and dental focal infection are possible causes of dermatological diseases, but have been the subjects of few reports to date. We have been treating such patients in our special clinic for more than 20 years.The purpose of the present study was to investigate the mouths of patients visiting our dental hospital over an 8-year period, with the aim of clarifying whether dental metal allergy and/or dental focal infection affects their dermatologic conditions.We surveyed all clinical records of the 185 patients who visited Niigata University Medical and Dental Hospital with chief complaints of dental metal allergy since 2002. Diagnostics of skin diseases, periodontal records, periapical lesions, dental caries, dental metal series patch test results and Electron Probed Micro-Analysis (EPMA) data were investigated. Ninety-two (49%) patients were suffering from pustulosis palmaris et plantaris and 20 (11%) patients had lichen planus. Eighty-two (49%) patients showed positive reactions on patch testing. Based on the result of patch tests, Ni showed the highest positivity rate (62%, 51 patients), but on EPMA, the number of patients with Ni as an allergen was 14 (27%). On the other hand, more than 98% of patients who showed positive reactions on patch test to Pd and Au had these metals in their dental prostheses. In addition, 112 (60%) patients showed the possibility of dental focal infection

    Detection of Multiple Human Papillomavirus Genotypes in Anal Carcinoma

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    Infection with human papillomavirus (HPV) is a major risk factor for development of anal squamous cell carcinoma. Despite over 100 genotypes of the virus, HPV 16 and 18 are considered pathogenic as they are seen in the majority of cervical and anal cancers. We have employed a custom microarray to examine DNA for several HPV genotypes. We aimed to determine the accuracy of our microarray in anal cancer DNA for HPV genotypes compared to the DNA sequencing gold standard

    Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways

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    Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins
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