What happens to our bones in space?
Astronaut study reveals that astronauts suffer significant bone loss during space missions.
A study of bone loss in 17 astronauts who flew aboard the International Space Station is providing a fuller understanding of the effects of space travel on the human body and steps that can mitigate it, crucial knowledge ahead of potential ambitious future missions. The research amassed new data on bone loss in astronauts caused by the microgravity conditions of space and the degree to which bone mineral density can be regained on Earth. It involved 14 male and three female astronauts, average age 47, whose missions ranged from four to seven months in space, with an average of about 5-1/2 months.
SLOVÍČKAbone loss úbytek kostní hmoty aboard sth na palubě čeho mitigate zmírnit, minimalizovat amass data shromáždit data microgravity conditions podmínky mikrogravitace bone mineral density denzita kostního minerálu regain sth znovu získat co, obnovit exhibit sth vykazovat co tibia holenní kost lower leg bérec novel nový recover znovu nabýt occur nastat, vzniknout weight-bearing nesoucí zátěž countermeasure protiopatření prevent zabránit, předejít fine structure jemná struktura thin řídnout, ztenčovat rod tyč(ka) disconnect sth odpojit, oddělit thicken zesílit, zhoustnout rebuild sth obnovit pose představovat, znamenat key concern klíčová obava/otázka aim mít v úmyslu, zamýšlet at the earliest nejdříve plateau ustálit se, stabilizovat |
A year after returning to Earth, the astronauts on average exhibited 2.1% reduced bone mineral density at the tibia - one of the bones of the lower leg - and 1.3% reduced bone strength. Nine did not recover bone mineral density after the space flight, experiencing permanent loss.
„We know that astronauts lose bone on long-duration spaceflight. What’s novel about this study is that we followed astronauts for one year after their space travel to understand if and how bone recovers,“ said University of Calgary professor Leigh Gabel, an exercise scientist who was the lead author of the research recently published in the journal Scientific Reports.
„Astronauts experienced significant bone loss during six-month spaceflights - loss that we would expect to see in older adults over two decades on Earth, and they only recovered about half of that loss after one year back on Earth,“ Gabel said.
The bone loss occurs because bones that typically would be weight-bearing on Earth do not carry weight in space. Space agencies are going to need to improve countermeasures - exercise regimes and nutrition - to help prevent bone loss, Gabel said.
„During spaceflight, fine bone structures thin, and eventually some of the bone rods disconnect from one another. Once the astronaut comes back to Earth, the remaining bone connections can thicken and strengthen, but the ones that disconnected in space can’t be rebuilt, so the astronaut’s overall bone structure permanently changes,“ Gabel said.
Space travel poses various challenges to the human body - key concerns for space agencies as they plan new explorations. For instance, NASA is aiming to send astronauts back to the moon, a mission now planned for 2025 at the earliest.
„There is a lot we still do not know regarding how microgravity affects human health, particularly on space missions longer than six months, and on the long-term health consequences,“ Gabel said. „We really hope that bone loss eventually plateaus on longer missions, that people will stop losing bone, but we don’t know.“
NAUČTE SE GRAMATIKU Z TEXTUDnes se blíž podíváme na slovo still, které najdeme ve větě: „There is a lot we still do not know...“ Slovo still znamená stále ve významu stále ještě a používá se v tomto významu hlavně v záporných větách, přičemž stojí před záporným pomocným slovesem, např. „I still don’t know what to do.“ V přítomném čase se můžeme se still setkat také v otázkách a v kladných větách, např. „Is Lucy still in hospital?“ „She is still working.“ V záporných větách se podobně jako still používá také yet, které však stojí vždy na konci věty. „I haven’t seen her yet.“ Still … not značí větší míru překvapení nebo netrpělivosti. Yet lze použít i v otázkách. Tady ale česky znamená už, např. „Has your passport arrived yet?“ Doplňte do vět still nebo yet (řešení najdete na konci článku): 1. The scientists … don’t know a lot about the effects of microgravity on human health. 2. I haven’t met your sister … . 3. Have you seen her …? No, not … . |
Text pochází z agentury Reuters
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Řešení:
1. still; 2. yet;
3. yet; yet