Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: V849 Ophiuchi or Nova Ophiuchi 1919 was a nova that lit up in 1919 in the constellation Ophiuchus and reached a brightness of 7.4 mag.

Answer: What constellation is V849 Ophiuchi a part of?


Question: A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. The Moon was Earths first satellite, but now many human- made "artificial satellites" orbit the planet. Thousands of artificial satellites have been put into orbit around Earth (Figure 1.2). We have even put satellites into orbit around the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. There are four main types of satellites. Imaging satellites take pictures of Earths surface for military or scientific purposes. Imaging satellites study the Moon and other planets. Communications satellites receive and send signals for telephone, television, or other types of communica- tions. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The International Space Station, the largest artificial satellite, is designed for humans to live in space while conducting scientific research. Humans have a presence in space at the International Space Station (ISS) (pictured in Figure 1.3). Modern space stations are constructed piece by piece to create a modular system. The primary purpose of the ISS is scientific research, especially in medicine, biology, and physics. Craft designed for human spaceflight, like the Apollo missions, were very successful, but were also very expensive, could not carry much cargo, and could be used only once. To outfit the ISS, NASA needed a space vehicle that was reusable and able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The resulting spacecraft was a space shuttle, shown in (Figure 1.4). Satellites operate with solar panels for energy. A photograph of the International Space Station was taken from the space shuttle Atlantis in June 2007. Construction of the station was completed in 2011, but new pieces and experiments continue to be added. A space shuttle has three main parts. The part you are probably most familiar with is the orbiter, with wings like an airplane. When a space shuttle launches, the orbiter is attached to a huge fuel tank that contains liquid fuel. On the sides of the fuel tank are two large "booster rockets." All of this is needed to get the orbiter out of Earths atmosphere. Once in space, the orbiter can be used to release equipment (such as a satellite or supplies for the International Space Station), to repair existing equipment such as the Hubble Space Telescope, or to do experiments directly on board the orbiter. When the mission is complete, the orbiter re-enters Earths atmosphere and flies back to Earth more like a glider than an airplane. The Space Shuttle program did 135 missions between 1981 and 2011, when the remaining shuttles were retired. The ISS is now serviced by Russian Soyuz spacecraft. Atlantis on the launch pad in 2006. Since 1981, the space shuttle has been the United States primary vehicle for carrying people and large equipment into space.

Answer: which of newtons laws of motion explains rocket propulsion?


Question: TGF-1 regulates bone metabolism and mediates bone turnover during postmenopause. Sclerostin negatively regulates Wnt signaling pathway and also has an important role in postmenopausal bone loss. Little is known about the relationship between serum TGF-1 and sclerostin during menopause. We compared serum levels of TGF-1 and sclerostin in pre- and postmenopausal women and assessed the potential correlations of these levels with each other and with serum levels of bone turnover markers and bone mineral density. A total of 176 women (58 premenopausal, 62 early postmenopausal, and 56 late postmenopausal) were included in this study. Serum TGF-1 level was significantly higher in early postmenopausal women compared with premenopausal (32.07.19 vs. 26.556.67 ng/ml, p=0.01) and late postmenopausal (32.07.19 vs. 28.657.70 pg/ml, p=0.031) women, and no significant differences in serum sclerostin levels were observed among the 3 groups. There was a significant negative correlation between TGF-1 and sclerostin in early postmenopausal women, but not in other groups of women. Based on multiple regression analysis, only TGF-1 (=-0.362; p=0.007) was an independent predictor of sclerostin during early postmenopause. Our findings suggest that serum TGF-1 level increases during postmenopause and declines in old age. Sclerostin production is inhibited by TGF-1 during early postmenopause.

Answer:
Sclerostin regulates what process?


