SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era

Source rupture processes of the 2016 Kumamoto, Japan, earthquakes estimated from strong-motion waveforms

The detailed source rupture process of the M 7.3 event (April 16, 2016, 01:25, JST) of the 2016 Kumamoto, Japan, earthquakes was derived from strong-motion waveforms using multiple-time-window linear waveform inversion. Based on the observations of surface ruptures, the spatial distribution of aftershocks, and the geodetic data, a realistic curved fault model was developed for source-process analysis of this event. The seismic moment and maximum slip were estimated as 5.5 × 1019 Nm (M w 7.1) and 3.8 m, respectively. The source model of the M 7.3 event had two significant ruptures. One rupture propagated toward the northeastern shallow region at 4 s after rupture initiation and continued with large slips to approximately 16 s. This rupture caused a large slip region 10–30 km northeast of the hypocenter that reached the caldera of Mt. Aso. Another rupture propagated toward the surface from the hypocenter at 2–6 s and then propagated toward the northeast along the near surface at 6–10 s. A comparison with the result of using a single fault plane model demonstrated that the use of the curved fault model led to improved waveform fit at the stations south of the fault. The source process of the M 6.5 event (April 14, 2016, 21:26, JST) was also estimated. In the source model obtained for the M 6.5 event, the seismic moment was 1.7 × 1018 Nm (M w 6.1), and the rupture with large slips propagated from the hypocenter to the surface along the north-northeast direction at 1–6 s. The results in this study are consistent with observations of the surface ruptures

MOESM1 of Source rupture process of the 2016 central Tottori, Japan, earthquake (M JMA 6.6) inferred from strong motion waveforms

Additional file 1. Estimation of the potential radiation region of the second wave packet observed in the high-frequency waveforms at near-fault stations

MOESM1 of Source rupture process of the 2016 central Tottori, Japan, earthquake (M JMA 6.6) inferred from strong motion waveforms

Additional file 1. Estimation of the potential radiation region of the second wave packet observed in the high-frequency waveforms at near-fault stations

管理栄養士養成課程の学生による「和食でのおもてなし献立」の食事スケッチの特徴―「和食継承」に着目した科目「栄養教育実習Ⅱ」を通して―

本研究の目的は、管理栄養士養成課程の学生が描いた「和食でのおもてなし献立」の特徴を明らかにすることである。平成28年度栄養教育実習Ⅱを履修した3年生79人を対象に食事スケッチ法を行った。スケッチから、料理構成、食材や調理法等の計25項目についてコード化し分析した。もてなす対象は家族が最も多かった。食事の構成として、主食・主菜・副菜・汁物がそろった食事をスケッチした者が多く、主食は「白飯」、主菜は「魚料理」、汁物は「味噌汁」が最も多く描かれていた。調理法は主菜では「焼く」、副菜では「煮る」が最も多く、調味料では、主菜では「塩」と「醤油」、副菜では「醤油」が最も多かった。食器に漆器をスケッチした者が52人（68.4％）、食具に箸をスケッチした者が60人（78.9％）という特徴もみられた。今後、管理栄養士養成の学年進行に伴い「和食でのおもてなし献立」への認識の経時的な変化を、他教科等での学習効果を含めて確認していきたい