17 research outputs found

    Multiple Transitions to Chaos in a Damped Parametrically Forced Pendulum

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    We study bifurcations associated with stability of the lowest stationary point (SP) of a damped parametrically forced pendulum by varying ω0\omega_0 (the natural frequency of the pendulum) and AA (the amplitude of the external driving force). As AA is increased, the SP will restabilize after its instability, destabilize again, and so {\it ad infinitum} for any given ω0\omega_0. Its destabilizations (restabilizations) occur via alternating supercritical (subcritical) period-doubling bifurcations (PDB's) and pitchfork bifurcations, except the first destabilization at which a supercritical or subcritical bifurcation takes place depending on the value of ω0\omega_0. For each case of the supercritical destabilizations, an infinite sequence of PDB's follows and leads to chaos. Consequently, an infinite series of period-doubling transitions to chaos appears with increasing AA. The critical behaviors at the transition points are also discussed.Comment: 20 pages + 7 figures (available upon request), RevTex 3.

    Discovery and Genetic Characterization of Novel Paramyxoviruses Related to the Genus Henipavirus in Crocidura Species in the Republic of Korea

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    Paramyxoviruses, negative-sense single-stranded RNA viruses, pose a critical threat to human public health. Currently, 78 species, 17 genera, and 4 subfamilies of paramyxoviruses are harbored by multiple natural reservoirs, including rodents, bats, birds, reptiles, and fish. Henipaviruses are critical zoonotic pathogens that cause severe acute respiratory distress and neurological diseases in humans. Using reverse transcription-polymerase chain reaction, 115 Crocidura species individuals were examined for the prevalence of paramyxovirus infections. Paramyxovirus RNA was observed in 26 (22.6%) shrews collected at five trapping sites, Republic of Korea. Herein, we report two genetically distinct novel paramyxoviruses (genus: Henipavirus): Gamak virus (GAKV) and Daeryong virus (DARV) isolated from C. lasiura and C. shantungensis, respectively. Two GAKVs and one DARV were nearly completely sequenced using next-generation sequencing. GAKV and DARV contain six genes (30 -N-P-M-F-G-L-50 ) with genome sizes of 18,460 nucleotides and 19,471 nucleotides, respectively. The phylogenetic inference demonstrated that GAKV and DARV form independent genetic lineages of Henipavirus in Crocidura species. GAKV-infected human lung epithelial cells elicited the induction of type I/III interferons, interferon-stimulated genes, and proinflammatory cytokines. In conclusion, this study contributes further understandings of the molecular prevalence, genetic characteristics and diversity, and zoonotic potential of novel paramyxoviruses in shrews

    首相による靖国神社参拝と日本メディア

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    Effects of an Exercise Program Combining Aerobic and Resistance Training on Protein Expressions of Neurotrophic Factors in Obese Rats Injected with Beta-Amyloid

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    In this study, the effects of a 12-week exercise program combining aerobic and resistance training on high-fat diet-induced obese Sprague Dawley (SD) rats after the injection of beta-amyloid into the cerebral ventricle were investigated. Changes in physical fitness, cognitive function, blood levels of beta-amyloid and metabolic factors, and protein expressions of neurotrophic factors related to brain function such as BDNF (brain-derived neurotrophic factor) in the quadriceps femoris, hippocampus, and cerebral cortex were analyzed. The subjects were thirty-two 10-week-old SD rats (DBL Co., Ltd., Seoul, Korea). The rats were randomized into four groups: β-Non-Ex group (n = 8) with induced obesity and βA25-35 injection into the cerebral ventricle through stereotactic biopsy; β-Ex group (n = 8) with induced obesity, βA25-35 injection, and exercise; S-Non-Ex group (n = 8) with an injection of saline in lieu of βA25-35 as the control; and S-Ex group (n = 8) with saline injection and exercise. The 12-week exercise program combined aerobic training and resistance training. As for protein expressions of the factors related to brain function, the combined exercise program was shown to have a clear effect on activating the following factors: PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha), FNDC5 (fibronectin type III domain-containing protein 5), and BDNF in the quadriceps femoris; TrkB (Tropomyosin receptor kinase B), FNDC5, and BDNF in the hippocampus; PGC-1α, FNDC5, and BDNF in the cerebral cortex. The protein expression of β-amyloid in the cerebral cortex was significantly lower in the β-Ex group than in the β-Non-Ex group (p < 0.05). The 12-week intervention with the combined exercise program of aerobic and resistance training was shown to improve cardiopulmonary function, muscular endurance, and short-term memory. The results demonstrate a set of positive effects of the combined exercise program, which were presumed to have arisen mainly due to its alleviating effect on β-amyloid plaques, the main cause of reduced brain function, as well as the promotion of protein expressions of PGC-1α, FNDC5, and BDNF in the quadriceps femoris, hippocampus, and cerebral cortex

    The Yasukuni issue and the current mass media of Japan

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