大家好!胖胖翔来了！最近做TPO，发现原来托福的阅读没有想象中简单，望各位指点！言归正传，享受今天的科技文吧～
Part I：Speaker 【Rephrase1】 Article 1 Tooth Sensor Watches Your Mouth
Transcript hided
[dialog: 1-14] A person’s mouth says a lot about them. Sounds obvious, but I’m talking less about what vocalizes and more about the way it behaves when we eat, drink, speak or even cough. Researchers at National Taiwan University believe that monitoring such oral behavior can provide doctors with a wealth of information about a patient’s dietary habits, dental hygiene and overall health. To test their idea, they built an accelerometer-based oral sensory system to identify how a mouth is being used based on the movement of its teeth. Placed in the mouths of eight people, a prototype system correctly recognized each person’s oral behavior up to 94 percent of the time. [Cheng-Yuan Li et al., Sensor-Embedded Teeth for Oral Activity Recognition] The researchers now want to build a wireless version that might someday fit inside a fake tooth or attach to a pair of braces. The sensor could send you or your doctor a message when you’re not sticking to your diet or not keeping your promise to quit smoking. Let’s hope they also build in an alarm for bad breath. That would benefit the person wearing the sensor, and everyone around them as well.
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Source: http://www.scientificamerican.com/podcast/episode.cfm?id=tooth-sensor-watches-your-mouth-13-08-05
Part II：Speed 【Time 2】 Article 2 4 Sky Events This Week: Harvest Moon, Green Giant, and Fall Equinox
This week two of the brightest planets join forces, and sky-watchers celebrate the change of seasons with a bright full moon.
Saturn and Venus.
Starting on Monday, September 16 after sunset, Venus and Saturn will be having a close encounter that will last most of the week. Low in the southwest sky, the second planet from the Sun will be the first visible—as the brightest star-like object in the entire heavens.
Look carefully next to Venus—binoculars may help—and fainter Saturn will pop out of the glare of dusk. Remember that since the two worlds are hot on the heels of the setting sun, they sink below the horizon less than an hour later.
The lord of the rings will pass only 4 degrees above the goddess of love—less than the width of your three middle fingers at arm’s length. As the week progresses both planets will appear lower in the sky each night with Venus sliding a bit towards the left of Saturn.
Even the smallest backyard telescope will show off Saturn’s iconic rings and even some of its brightest moons—like Titan and Enceladus.
Full Harvest Moon. Watch the near full moon rise soon after sunset, Wednesday, September 18, and reach official full moon status at 7:13 am EDT the next morning around when sun rises.
The full moon nearest the fall equinox is known as Harvest Moon and was probably coined by farmers in the Northern Hemisphere since its added light is said to have helped them gather in their crops.
Binoculars will easily show off the moon’s dark patches visible with the naked eyes. Called plains or maria in Latin, meaning seas, these are vast, ancient lava plains formed over billions of years ago when magma from the moon’s interior spilled out onto the surface, triggered by giant asteroid impacts.
With telescopes, the views get even more exciting—you can get sharp views of hundreds of ridges, mountains, cliffs, and craters up close.
Check out the Hitchhiker’s Guide to the Moon—a very detailed website dedicated to showing you exactly what you can see on the surface of the moon—generated for every day of the calendar.
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【Time 3】
Article 3
Moon and Uranus. All night long on Thursday, September 19 the seventh planet from the Sun, Uranus, will park itself near the moon.
The green giant is only 4 degrees away from the moon. The cosmic odd-couple will appear about four degrees apart in the sky—equal to 8 full moons side-by-side.
The green-colored ice giant has four times the width of Earth, but since it lies nearly 1.9 billion miles (3.1 billion kilometers) away from Earth, it’s barely visible to the naked eye—and only in very dark, pristine skies.
With the glare from the nearby moon, binoculars will be your best bet in spotting Uranus. Just look for a tiny greenish-blue disk in the field of view. By the way, the absorption of red light by methane in the atmosphere is what gives Uranus it’s cool cyan coloring.
Equal Day and Night. Autumn equinox is at 4:44 pm ET on Sunday, September 22, and officially marks the time of year we kick off the fall season in the northern hemisphere and the start of spring in the southern hemisphere. The word equinox comes from Latin meaning “equal night” and refers to the 12 hour long day and night that occurs only on this particular day of the year.
Looking at the mid-day position of the sun over the summer season, Northern Hemisphere sky-watchers will notice that it has been slowly sinking closer to the southern horizon, and creating ever longer shadows.
It’s only on the spring and autumnal equinox that the Sun rises due east and sets due west.
Astronomically speaking, the September equinox marks one of the four major turning points in the cycle of seasons. The Earth spins on its axis, which is tilted at 23.5 degrees with respect to its orbital plane. On these days, however, the Earth’s axis is neither tilted away nor towards the Sun, but has both northern and southern hemispheres experiencing equal amounts of sunshine.
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Source: http://newswatch.nationalgeographic.com/2013/09/16/4-sky-events-this-week-harvest-moon-green-giant-and-fall-equinox/
【Time 4】 Article 4 Insect leg cogs a first in animal kingdom Toothed gears enable young plant hoppers to synchronize limbs for jumping.
If you are a young plant hopper, leaping one metre in a single bound, you need to push off with both hind legs in perfect unison or you might end up in a spin. Researchers have discovered that this synchrony is made possible by toothed gears that connect the two legs when the insects jump.
Zoologists Malcolm Burrows and Gregory Sutton at the University of Cambridge, UK, say that this seems to be the first example in nature of rotary motion with toothed gears. They describe their findings today in Science.
The researchers' micrographs and videos of the jumping mechanism of the plant hopper Issus coleoptratus show that the joints that connect the hind legs to the body have rounded shapes and a series of tiny intermeshing teeth, each about 20 micrometres long.
When the insect jumps, the cog teeth join so that the two legs lock together, ensuring that they thrust at exactly the same time (see video above and image at left). “The gears add an extra level of synchronization beyond that which can be achieved by the nervous system,” says Burrows.
Infant plant hoppers, known as nymphs, can take off in just 2 milliseconds, reaching take-off speeds of almost 4 metres a second (see video below). For motions this rapid, some mechanical device is needed to keep the legs synchronized and to avoid lopsided jumps that might lead to the insects spinning out of control. The problem does not, however, arise in all jumping insects: whereas the attachments of plant hoppers' hind legs are adjacent to each other, the legs of grasshoppers and fleas attach to opposite the sides of the body and move in parallel planes. This helps to stabilize the insects and even enables them to jump one-legged.
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【Time 5】
Rotary club
The cog feature is analogous to the toothed gears that have been used in rotating machinery for millennia: they were described by Aristotle and Archimedes more than 2,000 years ago and they seem to have been used in ancient China even earlier. But, like the wheel, this human invention previously seemed to have little precedent in the natural world.
Gears are not the only mechanical solutions that were long thought to be unique to human engineering and then found to have been mastered by evolution: The screw-and-nut system is another example. In 2011, Alexander Riedel of the State Museum of Natural History in Karlsruhe, Germany, and his colleagues reported a screw-thread joint in the legs of a weevil beetle. Riedel considers the latest work on Issus “significant and exciting”. He says that it adds to the view that “most of the basic components of engineering have been developed in the natural world”. The reason that gears are not more common, Riedel adds, might be because there are different ways to synchronize limbs. Honeybees, for example, “couple the movement of both wings to stabilize their flight by using pegs, not as moving gears, but more like a Velcro.”
Curiously, the gears are found only in the plant hopper's nymph stage. When it sheds its exoskeleton for the last time to reach full adulthood, the gears disappear. In adults, the legs are instead synchronized by a simple, frictional-contact method.
Burrows and Sutton are not yet sure why this is so, but it might be because of ease of repair. “If a gear breaks it can’t be replaced in adults,” says Burrows. “But in nymphs, a repair can be made at the next of several moults.” Another reason might be that the larger and more rigid adult bodies make the frictional method work better than the gear mechanism, he adds.
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Source: http://www.nature.com/news/insect-leg-cogs-a-first-in-animal-kingdom-1.13723
【Time 6】 Article 5 Seeking the loneliest whale
An enigmatic whale roams the North Pacific, and next year Bruce Mate will lead a monthlong expedition to find it. Mate, director of Oregon State University’s Marine Mammal Institute in Newport, is no revenge-obsessed Captain Ahab. And the object of the quest is no ferocious leviathan: It is probably one of the generally meek baleen whales that prey on creatures close to the base of the food chain.
No one has ever seen this particular whale (“that they know of,” says Mate), but researchers know it’s out there. Its distinctive 52-hertz calls — similar to those of blue whales and fin whales but higher in pitch — have been recorded since 1989 by various researchers and the U.S. Navy.
Scientists have some notions about the mystery whale: It’s probably a male, says Mate, since its calls pierce the seas only during mating season. The whale has been tracked swimming as far as 11,000 kilometers in a single season, so it’s apparently healthy. Because the whale’s path doesn’t seem to line up with those of other species inhabiting the same region, the cetacean has been dubbed by some “the loneliest whale in the world.”
Mate doesn’t buy that moniker for a number of reasons. For one thing, he says, females typically don’t respond vocally to a male’s mating calls; they simply show up, so scientists would not have heard them. He also doesn’t think it’s the last member of an unknown species hunted to near extinction. Instead, it’s more likely to be a hybrid between two known species, or possibly an individual with a malformation in its sound-producing organs — the cetacean equivalent of a lisp. “It wouldn’t surprise me to find a large number of other whales in his vicinity when we find him.”
In fact, Mate is counting on it. Although the expedition will be funded by a team of documentary filmmakers searching specifically for the falsetto whale, Mate hopes to tag about a dozen other whales. That will give him a rare chance to learn what whales do between feeding season, when they gorge themselves to build up fat stores, and breeding season.
“We’re trying to track these whales from the season we know to the season that we don’t,” he says. “There hasn’t been an experiment yet where we didn’t have “an ‘a-ha’ moment. — Sid Perkins
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Source: http://www.sciencenews.org/view/generic/id/353007/description/Seeking_the_loneliest_whale
Part III： Obstacle
【Paraphase7】
Article 6
Are E-Cigarettes a Boon or a Menace? A new study says they may aid folks who want to quit smoking. But doctors fear there's a darker side to the electronic devices.
Electronic cigarettes may produce an aerosol vapor instead of smoke, but two new studies raise burning questions about their uses and risks.
E-cigs—as these battery-operated nicotine inhalers are commonly called—are increasingly popular, with a Wells Fargo financial analyst predicting that U.S. sales will double this year, going up to $1.7 billion.
Their visibility is becoming ever greater as well, with television and online marketing campaigns that feature celebrities like Jenny McCarthy and Stephen Dorff touting the pleasures of what they describe as more socially acceptable, "guilt-free" smoking.
The reasoning behind such claims is that e-cigs, which have the look of conventional cigarettes stylishly updated for the techno-age, produce vapor instead of ash or smoke. They also generally deliver lower amounts of nicotine than conventional cigarettes-a feature that may make e-cigarettes useful as an aid to smoking cessation.
Research Urgently Needed Whether that is so was the focus of a study published in The Lancet, which concluded that e-cigarettes were statistically comparable to nicotine patches in helping smokers quit over a six-month period.
But this was only the first study to compare e-cigarettes to an already established quitting aid. "There is still so much that is unknown about the effectiveness and long-term effects of e-cigarettes" that more research is "urgently needed," cautioned lead researcher Chris Bullen, director of the National Institute for Health Innovation at the University of Auckland in New Zealand. In that vein, Alexander Prokhorov, a smoking cessation expert at Houston's MD Anderson Cancer Center who was not involved in the study, commented, "I'm glad that there is finally some tangible research starting to appear." But several aspects worry him. "Nicotine is not a neutral substance," and in addition to being highly addictive, "it can be a poisonous substance."
Because e-cigs mimic the look and rituals of conventional cigarette smoking, there is a danger that rather than e-cigs helping you quit, "you may just switch to this product and continue using it," Prokhorov said. And since a smoker's dependence on nicotine remains, there is a risk for a relapse to smoking conventional cigarettes.
Not a Risk-Free Alternative Still, wouldn't there be some potential benefit to using only electronic cigarettes as an alternative to conventional cigarettes? "There is no question that e-cigarettes deliver less toxins than conventional cigarettes," said Stanton Glantz, director of the University of California, San Francisco's Center for Tobacco Control Research and Education. They may have as little as one-tenth of the toxins inhaled from burning tobacco, he said. (Related: "Cigarettes vs. e-Cigarettes: Which Is Less Environmentally Harmful?")
But that's not the entire story, he emphasized. "Whereas e-cigarettes are less dangerous than regular cigarettes, in an absolute sense they are negative," because they contain a number of toxic chemicals and ultrafine particles in addition to nicotine, and secondhand e-cig vapor could be harmful.
Moreover, he continued, "most people who use e-cigarettes also continue to use regular cigarettes; they are dual users. That means they are probably suffering all the risks from smoking." There is also a quality control issue for e-cigarettes, both Glantz and Prokhorov agreed. Unlike prescription nicotine patches, no electronic cigarettes have been approved for therapeutic use by the U.S. Food and Drug Administration.
"Further research is needed to assess the potential public health benefits and risks of electronic cigarettes and other novel tobacco products," said FDA spokesperson Jennifer Haliski. (Although the FDA's authority extends only to those e-cigs marketed for therapeutic purpose, with none having gained approval, it has announced its intention to propose broadening regulations to encompass additional categories of tobacco products that would include all electronic cigarettes.)
That's an important point, said Glantz, because the Lancet study's bottom line is that electronic cigarettes "are no worse than nicotine patches, but they are no better either." That leads to the question: "Why would you use something that has not been tested when there is something [with] quality control and [that] has been tested?"
Gateway Cigs for Teens? Another question, about the average age of electronic cigarette users, brings us to the second study. This one, conducted by the Centers for Disease Control and Prevention, shows that the number of U.S. middle and high school students using e-cigarettes doubled between 2011 and 2012, bringing the number nationwide who had tried e-cigs to 1.78 million.
That statistic is disturbing, said Tim McAfee, director of the CDC's Office on Smoking and Health, because about 90 percent of all smokers begin in their teens. E-cigarettes may be particularly attractive to youngsters because they are sold in a broad array of flavors, including cherry, vanilla, and even bubblegum.
"We know that this makes these products more appealing to children," he said. "The worry is that it is going to acclimatize kids to the behaviors that are like smoking. Until proven otherwise, we need to assume that this may increase their chances of taking up smoking with burn [conventional] cigarettes." Prokhorov shares that worry.
"My major concern is that this will be a gateway behavior, a potential risk of getting kids hooked on nicotine for life," he said. That's also why Glantz favors greater regulations, including banning the use of flavors (which are prohibited in conventional tobacco cigarettes) as well as prohibiting the sale of e-cigs to minors.
"In the current world, where cigarettes are ubiquitous with a marketing budget of $8 billion a year, we have to be careful and not make it easy" for vulnerable children to start using tobacco, said McAfee, whose budget for the CDC's 2012 Tips from Former Smokers campaign was $54 million.
"You go on YouTube and see how e-cigarettes are being glamorized, making smoking look sexy and rebellious," he said, which are the very elements that research has shown will attract kids to smoking. This is why media critics are comparing current e-cig ads to the ubiquitous cigarette ads of the 1950s, he added.
But going back to that era would be a mistake, said Prokhorov. "Psychologically, our society has just started to enjoy a tobacco-free and smoke-free life," he said. "The renaissance of cigarettes in e- or any other form is not a pretty picture."
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Source: http://news.nationalgeographic.com/news/2013/09/130916-electronic-cigarettes-smoking-nicotine-science/
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