The Hall conductance σ xy of two-dimensional lattice electrons with random potential is investigated. The change of σ xy due to randomness is focused on. It is a quantum phase transition where the sum rule of σ xy plays an important role. By the string (anyon) gauge, numerical study becomes possible in sufficiently weak magnetic field regime which is essential to discuss the floating scenario in the continuum model. Topological objects in the Bloch wavefunctions, charged vortices, are obtained explicitly. The anomalous plateau transitions ( ∆σ xy = 2, 3, • • • > 1) and the trajectory of delocalized states are discussed.

No abstract

Magneto-optical Kerr effects have been investigated for perovskite-type hole-doped oxides La 1Ϫx Sr x MnO 3 (0рxр0.3) and La 1Ϫx Sr x CoO 3 (0рxр0.3) in the photon energy range between 0.9 and 5.3 eV at room temperature. In La 1Ϫx Sr x MnO 3 , charge-transfer-type Kerr spectra are observed for the lowest (ϳ1.2 eV) and the second-lowest (ϳ3.5 eV) optical transitions that are likely to arise from electron excitations from the O 2 p to the majority-spin e g band and to the minority-spin t 2g band, respectively. In La 1Ϫx Sr x CoO 3 , a crystal-field-transition-type Kerr spectrum is observed that is assigned to the electron excitation from the bonding t 2g state to the antibonding e g state allowed by the strong hybridization effect between Co 3d and O 2p states. Different characters in the Hund's-rule coupling and covalency seem to cause such a difference in magneto-optical properties between ferromagnetic Mn and Co oxides. ͓S0163-1829͑98͒05336-3͔

To investigate the cognitive processes underlying creative inspiration, we tested the extent to which viewing or copying prior examples impacted creative output in art. In Experiment 1, undergraduates made drawings under three conditions: (a) copying an artist's drawing, then producing an original drawing; (b) producing an original drawing without having seen another's work; and (c) copying another artist's work, then reproducing that artist's style independently. We discovered that through copying unfamiliar abstract drawings, participants were able to produce creative drawings qualitatively different from the model drawings. Process analyses suggested that participants' cognitive constraints became relaxed, and new perspectives were formed from copying another's artwork. Experiment 2 showed that exposure to styles of artwork considered unfamiliar facilitated creativity in drawing, while styles considered familiar did not do so. Experiment 3 showed that both copying and thoroughly viewing artwork executed using an unfamiliar style facilitated creativity in drawing, whereas merely thinking about alternative styles of artistic representation did not do so. These experiments revealed that deep encounters with unfamiliar artworks-whether through copying or prolonged observation-change people's cognitive representations of the act of drawing to produce novel artwork.

No abstract

To investigate synovitis' influence on early knee osteoarthritis (EKOA) by serum biomarkers and magnetic resonance imaging (MRI) findings in Japanese women. We enrolled 255 women aged 30-70 without radiographic abnormalities (Kellgren-Lawrence grade ≥ 2). Knee injury, OA outcome scores (KOOS), clinical examinations, and standing radiograph were used for classification criteria of EKOA. Participants were classified into normal knee group and EKOA group. All participants underwent MRIs of their right knee. The amount of effusion-synovitis volume was quantified. We compared serum matrix metalloproteinases-3 levels (MMP-3), high-sensitivity C-reactive protein, interleukin-6, and adiponectin between the groups. The relationship between synovitis and EOKA was investigated using multiple linear regression. Fifty-four participants (21%) were classified as EKOA. Serum MMP-3 concentration and effusion-synovitis volume were higher in patients with EKOA (p = 0.025 and p = 0.001, respectively). Effusion-synovitis volume negatively correlated with all KOOS subscales and positively correlated with serum MMP-3 concentration. Serum MMP-3 concentration was associated with effusion-synovitis volume β = 0.60, p < 0.001). There was mildly active but definitive synovitis in EKOA. This was an observational study so that no conclusions can be drawn regarding cause-effect for synovitis and symptoms. Future studies should conduct follow-up of participants with synovitis to assess the progression of knee OA. Knee osteoarthritis (OA) is a major joint disease that causes chronic pain, stiffness, and disability, especially in the aging population 1,2. It requires high-cost treatment, such as arthroplasty, decreases productivity, and creates absence from work; therefore, knee OA imposes a substantial and growing burden on society 3. Although early intervention or preventive approaches are needed, the timing and identifying methodology are not established, as conventional standard diagnosis and assessment are conducted mainly based on the Kellgren-Lawrence (KL) grading on radiographs 4 , thus making it difficult to detect early and minute changes. Recently, new criteria for detecting early knee OA were proposed by the first international EKOA workshop (EKOA) without radiographic abnormalities 5 ; they allow identification of people with moderate knee symptoms who have same risk factors as those with definitive knee OA. EKOA prevalence was 9.5% in men and 15.0% in women, and the highest prevalence was noted in middle-aged females 6. Nevertheless, EKOA's etiology has not been well studied. Several biomarkers are frequently used to assess disease activity precisely and quantitatively. There are reports regarding the availability of serum biomarkers to evaluate synovitis at an early phase and to predict OA progression. Interleukin-6 (IL-6) and keratan sulfate levels increase in the early phase of knee OA accompanied by knee pain 7,8. Magnetic resonance imaging (MRI) is a useful imaging biomarker for assessing early phase of knee OA. The Framingham ...

No abstract

No abstract