TASK DEFINITION: Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
PROBLEM: Context: The authors describe a family with six patients with muscular dystrophy with a variable course. One is a compound heterozygote for CAPN3 mutations (calpainopathy) and the others have a single CAPN3 mutation. Linkage analysis and sequencing revealed a XK gene mutation (McLeod syndrome). This illustrates the variable phenotype of XK mutations and suggests the possibility that CAPN3 heterozygotes may have their condition caused by nonallelic mutations in other unrelated genes. 
 Question: Mutation of which gene is associated with McLeod syndrome?

SOLUTION: xk

PROBLEM: Context: We have dreams almost every night. Do you ever notice the colors of your dreams? Do you dream in black and white or do you dream in yellow, red and green? New research suggests that the type of television you watched as a child has a great effect on the color of your dreams. While almost all people under 25 dream in color, thousands of people over 55, all of whom were brought up with black and white TV sets, often dream in monochrome . "It suggests there could be a critical period in our childhood when watching films has a big impact on the way dreams are formed", said Eva Murzyn, a psychology student at Dundee University in Britain who carried out the study. Research from 1915 through the 1950s suggested that the vast majority of dreams are in black and white. But the tide turned in the sixties, and later results suggested that up to 83 percent of dreams contain some color. Since this period also marked the transition between black-and-white film and TV and Technicolor ,an obvious explanation was that the media had been painting people's dreams. However, there weren't any firm conclusions. But now Miss Murzyn believes she has proven the link. She made a survey of more than 60 people, half of whom were over 55 and half of whom were under 25. She asked the volunteers to answer a questionnaire on the color of their dreams and their childhood exposure to film and TV. She then analyzed her own data. Only 4.4 percent of the under-25s' dreams were black and white. The over-55s who had had access to color TV and film during their childhood also reported a very low proportion of just 7.3 percent. But the over-55s who only had access to black-and -white media reported dreaming in black and white about a quarter of the time. Even though they would have spent only a few hours a day watching TV or films, their attention and emotion would have been heightened during this time, leaving a deeper imprint on their mind, Miss Murzyn told the New Scientist. "The crucial time is between three and ten when we all begin to have the ability to dream", she said. 
 Question: In which magazine can you find the article?

SOLUTION: new scientist

PROBLEM: Context: People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments for this purpose. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a guitar, the whole instrument and the air inside it may vibrate when a single string is plucked. This causes constructive interference with the sound waves, which increases their amplitude. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds. There are three basic categories of musical instruments: percussion, wind, and stringed instruments. In Figure Researchers at Lawrence Berkeley National Laboratory are pioneering a new way to recover 100-year-old record- ings. Found on fragile wax cylinders and early lacquer records, the sounds reveal a rich acoustic heritage, including languages long lost. For more information on how to recover recordings, see [Link] MEDIA Click image to the left or use the URL below. URL: Ultrasound has frequencies higher than the human ear can detect (higher than 20,000 hertz). Although we cant hear ultrasound, it is very useful. Uses include echolocation, sonar, and ultrasonography. Animals such as bats, whales, and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. Figure 20.13 and the animation at the URL below show how a bat uses echolocation to locate insect prey. Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s 1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? Ultrasound can be used to "see" inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see an ultrasound image in Figure 20.15. You can see an animation showing how ultrasonography works at this URL: In this QUEST web extra, Stanford University astrophysicist Todd Hoeksema explains how solar sound waves are a vital ingredient to the science of helioseismology, in which the interior properties of the sun 
 Question: use of ultrasound by animals to locate objects they cannot see

SOLUTION:
echolocation