Iron-Based Heavy Quasiparticles in SrFe4_{4}Sb12_{12}: An Infrared Spectroscopic Study

Temperature-dependent infrared reflectivity spectra of SrFe$_{4}$Sb$_{12}$ has been measured. A renormalized Drude peak with a heavy effective mass and a pronounced pseudogap of 10 meV develops in the optical conductivity spectra at low temperatures. As the temperature decreases below 100 K, the effective mass ($m^{*}$) rapidly increases, and the scattering rate ($1/\tau$) is quenched. The temperature dependence of $m^{*}$ and $1/\tau$ indicates that the hybridization between the Fe 3d spins and the charge carriers plays an important role in determining the physical properties of SrFe$_{4}$Sb$_{12}$ at low temperatures. This result is the clear evidence of the iron-based heavy quasiparticles.Comment: 5 pages, 5 figure

Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Part 3. Validity study and establishment of the measurement scale: Subcommittee on Low Back Pain and Cervical Myelopathy Evaluation of the Clinical Outcome Committee of the Japanese Orthopaedic Association, Japan

AbstractBackgroundThe Japanese Orthopaedic Association decided to revise the JOA score for low back pain and to develop a new outcome measure. In February 2002, the first survey was performed with a preliminary questionnaire consisting of 60 evaluation items. Based on findings of that survey, 25 items were selected for a draft of the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The second survey was performed to confirm the reliability of the draft questionnaire. This article further evaluates the validity of this questionnaire and establishes a measurement scale.MethodsThe subjects of this study consisted of 355 patients with low back disorders of any type (201 men, 154 women; mean age 50.7 years). Each patient was asked to fill in a self-administered questionnaire. Superficial validity was checked in terms of the completion rate for filling out the entire questionnaire. Factor analysis was then performed to evaluate the validity of the questionnaire and establish a measurement scale.ResultsAs a result of the factor analysis, 25 items were categorized into five factors. The factors were named based on the commonality of the items: social function, mental health, lumbar function, walking ability, and low back pain. To establish a measurement scale for each factor, we determined the coefficient for each item so the difference between the maximum factor scores and minimum factor scores was approximately 100. We adjusted the formula so the maximum for each factor score was 100 and the minimum was 0.ConclusionsWe confirmed the validity of the JOA Back Pain Evaluation Questionnaire and est ablished a measurement scale

Selective labeling of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein

SPIE BiOS, 2008, San Jose, California, United StatesWataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Daisuke Kurihara, Shin-ichi Arimura, Nobuhiro Tsutsumi, Kiichi Fukui, Kazuyoshi Itoh, "Selective labeling of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein," Proc. SPIE 6860, Multiphoton Microscopy in the Biomedical Sciences VIII, 68601B (15 February 2008); https://doi.org/10.1117/12.768745

Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): Part 2. Endorsement of the alternative item

AbstractBackgroundA new self-administered questionnaire as an outcome measure for patients with cervical myelopathy was drawn up in Part 1 (Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, JOACMEQ). Because a question with regard to driving a car (C-41) was not suitable for this patient group, the authors composed an alternative question related to neck motion (C-41-2). The purposes of the present study were to perform a secondary survey on patients with cervical myelopathy and to statistically analyze the responses to validate the JOACMEQ, and also to determine if it was possible to convert item C-41 to the alternative question.MethodsA member of the Subcommittee on Low Back Pain and Cervical Myelopathy Evaluation from each hospital administered the questionnaire to more than 50 patients with cervical myelopathy in each hospital. The questionnaire consisted of 25 questions, 24 of which were extracted in the primary survey. The authors statistically examined whether it was possible to convert question C-41 to C-41-2.ResultsThree hundred and sixty-eight patients with cervical myelopathy were enrolled in the present study. No questions elicited no answer or “I am not sure” in more than 5% of patients except question C-41. There were no questions that the patients answered with difficulty. There was no tendency that was concentrated on one option as an answer to questions. There was a high correlation between questions C-41 and C-41-2. Spearman’s correlation coefficient and κ value showed that there was high coincidence between the two questions C-41 and C-41-2. It is possible to convert the question C-41 to the alternative question C41-2.ConclusionThe questionnaire has sufficient reliability for clinical use. It is possible that the JOACMEQ will prevail and become a global standard to evaluate outcomes in patients with cervical myelopathy

Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway.Sugiyamal Y., Fukui M., Kikuchi M., et al. Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam. New Journal of Physics 10, 033001 (2008); https://doi.org/10.1088/1367-2630/10/3/033001

Phase transition in traffic jam experiment on a circuit

The emergence of a traffic jam is considered to be a dynamical phase transition in a physics point of view; traffic flow becomes unstable and changes phase into a traffic jam when the car density exceeds a critical value. In order to verify this view, we have been performing a series of circuit experiments. In our previous work (2008 New J. Phys. 10 033001), we demonstrated that a traffic jam emerges even in the absence of bottlenecks at a certain high density. In this study, we performed a larger indoor circuit experiment in the Nagoya Dome in which the positions of cars were observed using a high-resolution laser scanner. Over a series of sessions at various values of density, we found that jammed flow occurred at high densities, whereas free flow was conserved at low densities. We also found indications of metastability at an intermediate density. The critical density is estimated by analyzing the fluctuations in speed and the density-flow relation. The value of this critical density is consistent with that observed on real expressways. This experiment provides strong support for physical interpretations of the emergence of traffic jams as a dynamical phase transition.Tadaki S.I., Kikuchi M., Fukui M., et al. Phase transition in traffic jam experiment on a circuit. New Journal of Physics 15, 103034 (2013); https://doi.org/10.1088/1367-2630/15/10/103034

Two-dimensional cellular automaton model of traffic flow with open boundaries

A two-dimensional cellular automaton model of traffic flow with open boundaries are investigated by computer simulations. The outflow of cars from the system and the average velocity are investigated. The time sequences of the outflow and average velocity have flicker noises in a jamming phase. The low density behavior are discussed with simple jam-free approximation.Comment: 14 pages, Phys. Rev. E in press, PostScript figures available at ftp://hirose.ai.is.saga-u.ac.jp/pub/documents/papers/1996/2DTR/ OpenBoundaries/Figs.tar.g

Supramolecular double-stranded Archimedean spirals and concentric toroids

Connecting molecular-level phenomena to larger scales and, ultimately, to sophisticated molecular systems that resemble living systems remains a considerable challenge in supramolecular chemistry. To this end, molecular self-assembly at higher hierarchical levels has to be understood and controlled. Here, we report unusual self-assembled structures formed from a simple porphyrin derivative. Unexpectedly, this formed a one-dimensional (1D) supramolecular polymer that coiled to give an Archimedean spiral. Our analysis of the supramolecular polymerization by using mass-balance models suggested that the Archimedean spiral is formed at high concentrations of the monomer, whereas other aggregation types might form at low concentrations. Gratifyingly, we discovered that our porphyrin-based monomer formed supramolecular concentric toroids at low concentrations. Moreover, a mechanistic insight into the self-assembly process permitted a controlled synthesis of these concentric toroids. This study both illustrates the richness of self-assembled structures at higher levels of hierarchy and demonstrates a topological effect in noncovalent synthesis