Eleven-year, 22-year and ~90-year solar cycles discovered in nitrate concentrations in a Dome Fuji (Antarctica) ice core

Ice cores are known to yield information about astronomical phenomena as well as information about past climate. We report time series analyses of annually resolved nitrate variations in an ice core, drilled at the Dome Fuji station in East Antarctica, corresponding to the period from CE 1610 to 1904. Our analyses revealed clear evidence of ~11, ~22, and ~90 year periodicities, comparable to the respective periodicities of the well-known Schwabe, Hale, and Gleissberg solar cycles. Our results show for the first time that nitrate concentrations in an ice core can be used as a proxy for past solar activity on decadal to multidecadal time scales. Furthermore, 11-year and 22-year periodicities were detected in nitrate variations even during the Maunder Minimum (1645-1715), when sunspots were almost absent. This discovery may support cyclic behavior of the solar dynamo during the grand solar minimum.Comment: Submitted to Proceedings of the Japan Academy, Series

胎盤抽出物がヒト骨肉腫細胞株Saos-2の細胞増殖、I型コラーゲン産生およびALP分泌に及ぼす効果

Porcine placenta extract (P-placenta) is widely applied in medicine and cosmetics. However, few studies have examined the effect of the extract on the cellular behavior of the osteoblastic cell line Saos-2. Here, we demonstrated that P-placenta enhances the proliferation, collagen type I production, and alkaline phosphatase (ALP) secretion of Saos-2 in vitro. Proliferation of Saos-2 was assessed by MTT and DNA synthesisassays. Type I collagen production and ALP secretion were evaluated using enzyme-linked immunosorbent assay and ALP assays. The cells were treated with/without 20, 200 and 2000 g/ml of P-placenta for 24 h. We found that 200 g/ml P-placenta significantly induced the proliferation of Saos-2 and enhanced type I collagen production and ALP secretion. The results indicate that P-placenta controls the cellular behavior of osteoblasts,resulting in the secretion of early bone-related biomarkers

Integrity Analysis of Authenticated Encryption Based on Stream Ciphers

We study the security of authenticated encryption based on a stream cipher and a universal hash function. We consider ChaCha20-Poly1305 and generic constructions proposed by Sarkar, where the generic constructions include 14 AEAD (authenticated encryption with associated data) schemes and 3 DAEAD (deterministic AEAD) schemes. In this paper, we analyze the integrity of these schemes both in the standard INT-CTXT notion and in the RUP (releasing unverified plaintext) setting called INT-RUP notion. We present INT-CTXT attacks against 3 out of the 14 AEAD schemes and 1 out of the 3 DAEAD schemes. We then show INT-RUP attacks against 1 out of the 14 AEAD schemes and the 2 remaining DAEAD schemes. We next show that ChaCha20-Poly1305 is provably secure in the INT-RUP notion. Finally, we show that 4 out of the remaining 10 AEAD schemes are provably secure in the INT-RUP notion

Experimental and theoretical diagnoses of yearly-scale nitrate ion spikes observed in a Dome Fuji shallow ice core

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27日（火） 国立国語研究所 ２階講

Single-cell dynamics of pannexin-1-facilitated programmed ATP loss during apoptosis

死にゆく細胞のATP濃度変化を詳細に可視化することに成功 --積極的にATP濃度を下げる因子を明らかに--. 京都大学プレスリリース. 2020-10-22.ATP is essential for all living cells. However, how dead cells lose ATP has not been well investigated. In this study, we developed new FRET biosensors for dual imaging of intracellular ATP level and caspase-3 activity in single apoptotic cultured human cells. We show that the cytosolic ATP level starts to decrease immediately after the activation of caspase-3, and this process is completed typically within 2 hr. The ATP decrease was facilitated by caspase-dependent cleavage of the plasma membrane channel pannexin-1, indicating that the intracellular decrease of the apoptotic cell is a ‘programmed’ process. Apoptotic cells deficient of pannexin-1 sustained the ability to produce ATP through glycolysis and to consume ATP, and did not stop wasting glucose much longer period than normal apoptotic cells. Thus, the pannexin-1 plays a role in arresting the metabolic activity of dead apoptotic cells, most likely through facilitating the loss of intracellular ATP

Intraoperative obturator nerve injury reconstructed using a PGA-collagen tube: Three case reports

We herein report three cases of obturator nerve injury, which is rare in gynecological surgery. In all cases, it was difficult to suture both nerve ends without tension. Therefore, we used a PGA-collagen tube to interpose the nerve defect. After follow-ups of at least seven months, all three patients were able to adduct the hip joint and medial thigh sensations also mproved. These results suggest the potential of a PGA-collagen tube in the treatment of obturator nerve injury

Tsunami run-up heights of the 2003 Tokachi-oki earthquake

Tsunami height survey was conducted immediately after the 2003 Tokachi-oki earthquake. Results of the survey show that the largest tsunami height was 4 m to the east of Cape Erimo, around Bansei-onsen, and locally at Mabiro. The results also show that the tsunami height distribution of the 2003 Tokachi-oki earthquake is clearly different from that of the 1952 Tokachi-oki earthquake, suggesting the different source areas of the 1952 and 2003 Tokachioki earthquakes. Numerical simulation of tsunami is carried out using the slip distribution estimated by Yamanaka and Kikuchi (2003). The overall pattern of the observed tsunami height distribution along the coast is explained by the computed ones although the observed tsunami heights are slightly smaller. Large later phase observed at the tide gauge in Urakawa is the edge wave propagating from Cape Erimo along the west coast of the Hidaka area.The 2003 Tokachi-oki earthquak