Marine Isotope Stage 3 and Holocene relative sea level variations in East Antarctica derived from glacial isostatic adjustment modelling

第3回極域科学シンポジウム　横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日（月）、27日（火） ２階ラウン

Design and optimization of a wideband impact mode piezoelectric power generator

This paper proposes a new design of an impact mode piezoelectric power generator that is able to operate in a wide frequency bandwidth by using a round piezoelectric ceramic as the energy converter. The evaluation results show that the output of the power generator can be optimized by implementing a so-called indirect impact configuration. To realize this type of configuration, a shim plate is placed between the piezoelectric ceramic and the hitting structure. At a certain base excitation frequency, the output efficiency of this configuration increases to about 4.3 times that of the direct impact configuration. Furthermore, it is demonstrated that the designated power generator is able to generate electric energy up to approximately 1.57 mJ within 120 s from the vibration of a moving vehicle

Spatial distribution and volume of Antarctic Ice Sheet at Last Glacial Maximum

第2回極域科学シンポジウム/第31回極域地学シンポジウム 11月16日（水） 国立国語研究

High-resolution spectroscopy and single-photon Rydberg excitation of reconfigurable ytterbium atom tweezer arrays utilizing a metastable state

We present an experimental system for Rydberg tweezer arrays with ytterbium (Yb) atoms featuring internal state manipulation between the ground ${}^1$S$_0$ and the metastable ${}^3$P$_2$ states, and single-photon excitation from the ${}^3$P$_2$ to Rydberg states. In the experiments, single Yb atoms are trapped in two-dimensional arrays of optical tweezers and are detected by fluorescence imaging with the intercombination ${}^1$S$_0 \leftrightarrow {}^3$P$_1$ transition, and the defect-free single atom arrays are prepared by the rearrangement with the feedaback. We successfully perform high-resolution ${}^1$S$_0\leftrightarrow {}^3$P$_2$ state spectroscopy for the single atoms, demonstrating the utilities of this ultranarrow transition. We further perform single-photon excitation from the ${}^3$P$_2$ to Rydberg states for the single atoms, which is a key for the efficient Rydberg excitation. We also perform a systematic measurement of a complex energy structure of a series of D states including newly observed ${}^3$D$_3$ states. The developed system shows feasibility of future experiments towards quantum simulations and computations using single Yb atoms.Comment: 10 pages, 9 figure

East Antarctic deglaciation and the link to global cooling during the Quaternary: evidence from glacial geomorphology and 10Be surface exposure dating of the Sør Rondane Mountains, Dronning Maud Land

AbstractReconstructing past variability of the Antarctic ice sheets is essential to understand their stability and to anticipate their contribution to sea level change as a result of future climate change. Recent studies have reported a significant decrease in thickness of the East Antarctic Ice Sheet (EAIS) during the last several million years. However, the geographical extent of this decrease and subsequent isostatic rebound remain uncertain. In this study, we reconstruct the magnitude and timing of ice sheet retreat at the Sør Rondane Mountains in Dronning Maud Land, East Antarctica, based on detailed geomorphological survey, cosmogenic exposure dating, and glacial isostatic adjustment modeling. Three distinct deglaciation phases are identified for this sector during the Quaternary, based on rock weathering and 10Be surface exposure data. We estimate that the ice sheet thinned by at least 500 m during the Pleistocene. This thinning is attributed to the reorganization of Southern Ocean circulation associated with global cooling into the Pleistocene, which reduced the transport of moisture from the Southern Ocean to the interior of EAIS. The data also show that since the Last Glacial Maximum the ice surface has lowered less than ca 50 m and that this lowering probably started after ca 14 ka. This suggests that the EAIS in Dronning Maud Land is unlikely to have been a major contributor to postglacial sea-level rise and Meltwater pulse 1A

Dual induction of caspase 3- and transglutaminase-dependent apoptosis by acyclic retinoid in hepatocellular carcinoma cells

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma has a high mortality rate due to its rate of recurrence. Acyclic retinoid prevents recurrence of hepatocellular carcinoma in patients after surgical removal of their primary tumors by inducing apoptosis in hepatocellular carcinoma cells, although the molecular mechanisms of action are not understood.</p> <p>Methods</p> <p>Human hepatocellular carcinoma cells in culture, as well as nude mice transplanted with hepatocellular carcinoma cells and rats given with <it>N</it>-diethylnitrosamine were treated with acyclic retinoid. Changes in activated caspase 3 and transglutaminase 2 (TG2) levels, Sp1 cross-linking and its activities, expression of epidermal growth factor receptor, and apoptotic levels were measured.</p> <p>Results</p> <p>Acyclic retinoid simultaneously stimulated the activation of caspase 3, and the expression, nuclear localization and crosslinking activity of TG2, resulting in crosslinking and inactivation of the transcription factor, Sp1, thereby reducing expression of epidermal growth factor receptor and cell death in three hepatocellular carcinoma cell lines. These effects were partially restored by a caspase inhibitor, transfection of antisense TG2, restoration of functional Sp1, or an excess of epidermal growth factor. Nuclear expression of TG2 and crosslinked Sp1, as also activated caspase 3 were found in both hepatocellular carcinoma cells transplanted into nude mice and cancerous regions within the liver in <it>N</it>-diethylnitrosamine-induced hepatocarcinogenesis model in rats, following treatment of animals with acyclic retinoid.</p> <p>Conclusions</p> <p>Treatment with acyclic retinoid produces a dual activation of caspase 3 and TG2 induced apoptosis of hepatocellular carcinoma cells via modification and inactivation of Sp1, resulting in reduced expression of epidermal growth factor receptor.</p

Reappraisal for the melting history of the Greenland Ice sheet from geological analysis on the raised beach deposits

第2回極域科学シンポジウム　共通セッション「大気-海洋-雪氷-固体地球の相互作用」 11月15日（火） 統計数理研究所 3階セミナー室

Glacial melting and uplift estimations around the Sør-Rondane Mountains of the East Antarctica since the Pliocene

第2回極域科学シンポジウム/第31回極域地学シンポジウム 11月16日（水） 国立国語研究

Some remarks on the depth of the continental shelf around the Antarctic continental margin

第6回極域科学シンポジウム[OG] 地圏11月16日（月）　国立極地研究所１階交流アトリウ