隅田金属日誌(墨田金属日誌) 「二巡目の検査でも甲状腺がんは出てるから『過剰診断論』はないね」(岩波『科学』)

岩波の『科学』4月号を読んだのだがねえ。過剰検査論の否定がトテも面白い。フクシマの被害を過小に見せかけるための「福島県の甲状腺がん多発は過剰検査の結果、原発事故のせいではない」が明確に否定されている。 過剰検査論の骨子は「過剰診断で健康上は問題にならない小さい病変まで掘り起こされた」である。小さい…

海底に住むワームが金属性の牙を持つ理由とは?

BloodwormやGlyceraとして知られる環形動物の一部は、長さ1mmほどの小さい銅製の牙を使って獲物を捕らえ、まひ毒を注入することで知られています。これらの種がなぜこのような牙を持つのか、研究により新たな知見がもたらされました。 A multi-tasking polypeptide from bloodworm jaws: Catalyst, template, and copoly…

NASA’s OSIRIS-REx probe will visit a second asteroid

NASA’s OSIRIS-REx spacecraft will have another mission after it drops off a sample from the asteroid Bennu. The agency has extended the probe’s mission to have it study the near-Earth asteroid Apophis for 18 months. The mission will be renamed OSIRIS-APEX (OSIRIS-Apophis Explorer), and the craft will maneuver toward the space rock 30 days after its September 24th, 2023 Earth fly-by. It won’t gather a sample, though. Instead, it will blast the surface with thrusters to expose the subsurface for examination.

Apophis originally drew interest over fears it would strike the Earth in 2029. Researchers put that worry to rest, but it’s still a highly valuable subject. It will have the closest approach of any known asteroid its size (about 1,000ft), and scientists are eager to study the effect of Earth’s gravitational pull on the object. And unlike Bennu, which is tied to carbonaceous chondrite meteorites, Apophis is associated with the regular chondrite variety.

The extension won’t come cheap. A visit to Apophis will add $200 million to the cost ceiling of a mission that’s already expected to cost $1.16 billion. Even so, it might be worthwhile if it helps humanity better understand asteroids and the risks they may pose to Earth.