Order-disorder oscillations in exciton-polariton superfluids

The dynamics of an exciton-polariton superfluid resonantly pumped in a semiconductor microcavity are investigated by mean-field theory. Modulational instability develops into crystalline order and then ordered and disordered states alternately form. A supersolid-like state is also found, in which superflow coexists with crystalline order at rest.Comment: 5 pages, 3 figures, 6 movie

Penetration of a vortex dipole across an interface of Bose-Einstein condensates

The dynamics of a vortex dipole in a quasi-two dimensional two-component Bose-Einstein condensate are investigated. A vortex dipole is shown to penetrate the interface between the two components when the incident velocity is sufficiently large. A vortex dipole can also disappear or disintegrate at the interface depending on its velocity and the interaction parameters.Comment: 7 pages, 9 figure

Symmetry breaking Rayleigh-Taylor instability in a two-component Bose-Einstein condensate

The interfacial instability and subsequent dynamics in a phase-separated two-component Bose-Einstein condensate with rotation symmetry are studied. When the interatomic interaction or the trap frequency is changed, the Rayleigh-Taylor instability breaks the rotation symmetry of the interface, which is subsequently deformed into nonlinear patterns including mushroom shapes.Comment: 5 pages, 5 figure

Simultaneous ground-based and satellite observations of natural VLF waves in Antarctica: A case study of downward ionospheric penetration of whistler-mode waves

AbstractTo investigate downward ionospheric-penetration characteristics of VLF (several hundred Hz to 17.8 kHz) whistler-mode waves, we conducted simultaneous observations (in 2006) of natural VLF waves using both ground stations in Antarctica and the Japanese Akebono satellite. The ground-based and satellite observations included an interesting event for which both observed similar VLF waves. In this study, we theoretically calculate down-going whistler-mode wave propagation based on ground-satellite observations using the full-wave analysis. In a case study, the observed wave-normal angles were approximately 140–160 degrees for a dayside chorus event on 15 March 2006. The theoretical calculation showed that the wave-normal angles for ionospheric penetration should be around 155.6 degrees, with its angular width of approximately 2 degrees. Moreover, the wave-energy loss due to ionospheric penetration is estimated at 20.4 dB based on our theoretical calculation, in accordance with the observed 17–19 dB

B\'enard-von K\'arm\'an vortex street in an exciton-polariton superfluid

The dynamics of an exciton--polariton superfluid resonantly injected into a semiconductor microcavity are investigated numerically. The results reveal that a B\'enard--von K\'arm\'an vortex street is generated in the wake behind an obstacle potential, in addition to the generation of quantized vortex dipoles and dark solitons. The vortex street is shown to be robust against a disorder potential in a sample and it can be observed even in time-integrated measurements.Comment: 4 pages, 3 figure

Lung adenocarcinoma presenting as a solitary gingival metastasis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Gingival metastases are very rare and generally occur in disseminated tumors. We report a case of solitary gingival metastasis of lung cancer.</p> <p>Case presentation</p> <p>We report the case of a 74-year-old asymptomatic Caucasian woman affected by a rapidly growing, painless gingival swelling. Histopathologic examination of the excisional biopsy showed metastasis of poorly differentiated thyroid transcription factor 1-positive adenocarcinoma. A total-body computed tomographic scan revealed a tumor of the right lung lower lobe with ipsilateral, mediastinal lymph node swelling. Moreover, bone scintigraphy revealed no bone metastases. No other metastases were found, so we planned a multi-modal therapeutic approach with a curative intent. However, the tumor proved to be intrinsically resistant and highly aggressive.</p> <p>Conclusion</p> <p>The presentation of solitary gingival metastasis is exceptional. In view of its rapid clinical evolution, our case confirms that gingival metastasis is an important prognostic factor. This behavior raises the question whether the poor prognosis for patients with tumors with oral metastases depends on its diffuse spread or on its highly malignant nature.</p

The pulsating aurora and natural VLF emissions observed at Syowa Station

第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月16日（水） 統計数理研究所 3階リフレッシュフロ