【Native Speaker每日综合训练—43系列】【43-03】科技

Cassidy大洁洁

内容：Cassidy大洁洁 编辑：Cassidy大洁洁

Stay tuned to ourlatest post! Follow us here ---> http://weibo.com/u/3476904471

Part I: Speaker

Kids who exercise don't sweat tests

Hey kids, here’s a good reason to work up a sweat: when young people exercise for an hour each day it also helps boost their brain power. That’s according to a study of more than 200 kids in the journal Pediatrics. [Charles H. Hillman et al: Effects of the FITKids Randomized Controlled Trial on Executive Control and Brain Function]
Seven, eight and nine year-olds were randomly selected to enroll in an after-school exercise program or be placed on a wait list. The exercisers performed much better on intellectual tests. And there was a dosage effect: kids who spent more time in the program performed even better than kids who were enrolled in the program but had spotty attendance.
Government guidelines already recommend that everyone aged 6 to 17 engage in an hour or more of moderate- and vigorous-intensity physical activity daily, but many kids still do not meet this threshold. Better cognitive capabilities could be a selling point for more exercise.
The study could not tease apart how much increased physical fitness versus social interactions in the exercise program may have contributed to better accuracy on cognitive tasks. But other work has suggested that exercise is better for cognition than social interactions alone. Regardless, a workout that offers both is a win-win.

Source: Scientific American
http://www.scientificamerican.com/podcast/episode/kids-who-exercise-don-t-sweat-tests/

[Rephrase 1]

Cassidy大洁洁

Part II: Speed

What’s a Pufferfish? Explaining Animal Behind Mystery Circles
Posted by Mary Bates in Weird & Wild on August 21, 2013

[Time 2]
Mystery circles on the seafloor have intrigued divers for decades, and scientists recently identified the culprit: a new species of pufferfish.

This tiny architect—which builds elaborate nests to woo females—has also captured the hearts of our readers, with more than 60 comments and 30,000 Facebook likes on our story about the phenomenon. So we wondered: What’s a pufferfish?
It turns out there are 120 pufferfish species in the Tetraodontidae family. The fish live in warm, coastal waters around the world, and some even live in fresh water.  They tend to have tapered, torpedo-shaped bodies with bulbous heads and large eyes.

Pufferfish have four large teeth that are fused together to form a beak-like structure. While some species of pufferfish use their beaks to scrape algae off rocks and coral, certain large species use their beaks to crack open crustaceans and shellfish.
They also come in a variety of colors and sizes, from the 1-inch-long (2.5-centimeter-long) pygmy puffer to the giant freshwater puffer, which can reach 2 feet (0.6 meter) in length.

Puffer Upper
Pufferfish are best known for their ability to “puff up” into a ball several times their normal size. Scientists think the fish developed this defense to compensate for their slow, clumsy swimming style.
A pufferfish might look like an easy meal to a predator, but if pursued, it will quickly fill its extremely elastic stomach with large amounts of water, making itself much bigger and nearly spherical in shape (below).
Most species are also covered with small spines that only stick out when they are inflated. A predator that doesn’t heed the pufferfish’s warning may be in danger of choking to death on the spiky, spherical fish. (Watch a video of pufferfish inflating to escape prey.)

But the pufferfish’s defenses don’t stop there: Many species are highly poisonous. Certain pufferfish contain the neurotoxin tetrodotoxin, mostly concentrated in the fish’s liver, gonads, and skin. Although this potent toxin can kill some predators (including people), others, such as sharks, are able to withstand a pufferfish meal with no ill effects.
[343 words]

[Time 3]
Dangerous Delicacy
Despite the risks of ingesting tetrodotoxin, pufferfish are a delicacy in many parts of the world.

In Japan, only trained and licensed chefs may prepare pufferfish, known as fugu. Young chefs spend years learning how to properly prepare fugu, making sure that it is free of the toxic liver, gonads, and skin. Even with these precautions, several people die each year after ingesting improperly prepared fugu dishes.

Symptoms of tetrodotoxin poisoning begin with numbness in the tongue and lips, followed by headache, dizziness, and vomiting. In the worst cases, sufferers experience rapid heart rate, decreased blood pressure, muscle paralysis, and respiratory distress. Death can occur within four to six hours. The toxin typically kills by paralyzing diaphragm muscles and causing respiratory failure.

Not all pufferfish are toxic, and some species are easier to prepare safely. To keep U.S. consumers safe, the Food and Drug Administration has teamed up with scientists at the Smithsonian’s National Museum of Natural History to create a library of pufferfish DNA. When a tetrodotoxin poisoning occurs, officials can use the library to identify the species of pufferfish that was consumed and determine whether it was illegally imported.

Zombie Fish
The pufferfish’s tetrodotoxin is so powerful that some believe it even has the power to create real-life zombies.
In the 1980s, ethnobotanist Wade Davis—now a National Geographic Society Explorer in Residence—traveled to Haiti to investigate reports of zombification. During his research, Davis discovered that the voodoo sorcerers believed to be capable of turning people into zombies used homemade powders in their rituals. Davis collected and tested samples of zombie powders and discovered they contained pufferfish tetrodotoxin.

Pufferfish tetrodotoxin works in part by preventing neurons from firing. People who ingest the toxin and don’t die within the first 24 hours typically survive, although they often fall into a coma-like state for several days.

Completely paralyzed but fully conscious, the victims are pronounced dead and buried. After a few days, the voodoo sorcerer returns and claims the body, which then seems to rise from the dead.
[341 words]

Source: National Geographic
http://newswatch.nationalgeographic.com/2013/08/21/whats-a-pufferfish-explaining-animal-behind-mystery-circles/

Hawking radiation mimicked in the lab
By Ron Cowen | 12 October 2014

[Time 4]
Scientists have come closer than ever before to creating a laboratory-scale imitation of a black hole that emits Hawking radiation, the particles predicted to escape black holes due to quantum mechanical effects.

The black hole analogue, reported in Nature Physics1, was created by trapping sound waves using an ultra cold fluid. Such objects could one day help resolve the so-called black hole ‘information paradox’ - the question of whether information that falls into a black hole disappears forever.

The physicist Stephen Hawking stunned cosmologists 40 years ago when he announced that black holes are not totally black, calculating that a tiny amount of radiation would be able to escape the pull of a black hole2. This raised the tantalising question of whether information might escape too, encoded within the radiation.
Hawking radiation relies on a basic tenet of quantum theory — large fluctuations in energy can occur for brief moments of time. That means the vacuum of space is not empty but seethes with particles and their antimatter equivalents. Particle-antiparticle pairs continually pop into existence only to then annihilate each other. But something special occurs when pairs of particles emerge near the event horizon — the boundary between a black hole, whose gravity is so strong that it warps space-time, and the rest of the Universe. The particle-antiparticle pair separates, and the member of the pair closest to the event horizon falls into the black hole while the other one escapes.

Hawking radiation, the result of attempts to combine quantum theory with general relativity, comprises these escaping particles, but physicists have yet to detect it being emitted from an astrophysical black hole. Another way to test Hawking’s theory would be to simulate an event horizon in the laboratory.
[286 words]

[Time 5]
To this end, Jeff Steinhauer, a physicist at the Technion-Israel Institute of Technology in Haifa, used a collection of rubidium atoms chilled to less than 1-billionth of a degree above absolute zero. At such temperatures, the atoms are tightly packed and behave as a single, fluid quantum object and so can be easily manipulated. The cold temperature also ensures that the fluid, known as a Bose-Einstein condensate, provides a silent medium for the passage of sound waves that arise from quantum fluctuations.

Using laser light, Steinhauer manipulated the fluid to flow faster than the speed of sound. Like a swimmer battling a strong current, sound waves travelling against the direction of the fluid become ‘trapped’. The condensate thus becomes a stand-in for the gravitational event horizon.

Pairs of sound waves pop in and out of existence in a laboratory vacuum, mimicking particle-antiparticle pairs in the vacuum of space. Those that form astride this sonic event horizon become the equivalent of Hawking radiation. To amplify these sound waves enough for his detectors to pick them up, Steinhauer established a second sonic event horizon inside the first, adjusting the fluid so that sound waves could not pass this second event horizon, and are bounced back. As the soundwaves repeatedly strike the outer horizon, they create more pairs of soundwaves, amplifying the Hawking radiation to detectable levels.

Some researchers say it’s still not clear how closely this laboratory model, which took Steinhauer five years to perfect, mimics Hawking radiation. The amplification in Steinhauer’s model allows him to detect only one frequency of the radiation, so he cannot be sure it has Hawking’s predicted intensity at different frequencies that true Hawking radiation would have.

Steinhauer is now working to develop the technology to study his artificial black hole without having to amplify the sonic radiation. This could allow him to use his ‘Hawking radiation’ to explore the information paradox.
[315 words]

[Time 6]
It might also help physicists in their question to reconcile quantum theory with gravity, the only force in nature that has not been accommodated within quantum mechanics. Because Hawking radiation draws on both quantum mechanics and general relativity, it is a first step in addressing how to marry the two - and an artificial black hole might provide an opportunity to study how this might be done.

Experimental physicist Daniele Faccio of Heriot-Watt University in Edinburgh calls the work “possibly the most robust and clear-cut evidence” that laboratory models can emulate phenomena at the interface between general relativity and quantum mechanics. In 2010, Faccio and his colleagues reported that they had detected an analogue of Hawking radiation3, but the team has since acknowledged they had seen a different phenomenon.

However Physicist Ted Jacobson of the University of the Maryland in College Park, who suggested in 1999 that analogue radiation could be seen in the laboratory4, says that the possibility of gleaning new insights about black holes from the sonic experiment remains “far fetched”, for now. For Jacobson, the value of the experiment lies in exploring the physics of ultracold atoms.

But even if the sonic radiation as it stands is not a perfect match, William Unruh, a theoretical physicist at the University of British Columbia in Vancouver points out that “it is the closest anyone has come” to detecting Hawking radiation. “I find it a very exciting and interesting experiment,' he says.
[242 words]

Source: Nature
http://www.nature.com/news/hawking-radiation-mimicked-in-the-lab-1.16131

Cassidy大洁洁

Part III: Obstacle

Once more, with feeling
Oct 11th 2014

[Paraphrase 7]
PROSTHETIC body parts are nothing new. In 2000 researchers published in the Lancet an account of a 3,000 year old Egyptian mummy with a wooden big toe grafted to her right foot. It had been expertly carved, and painted to match her skin tone. Making limbs that look natural, though, is one thing. Making them feel real is much harder, because a real limb is constantly talking to the brain that controls it. That lack of feedback, and the discomfort it causes, is one reason why between a quarter and a half of people fitted with an artificial limb end up abandoning it. But two papers just published in Science Translational Medicine report progress towards dealing with the problem of feedback.

Daniel Tan and his colleagues at the Louis Stokes Veterans Affairs Medical Centre, in Cleveland, Ohio, created signals that appeared to come from the prosthetic arms of two volunteers by implanting electrodes around nerves in the amputees’ stumps (see picture). When they connected these electrodes to a machine that generated electrical signals, both volunteers reported sensations which seemed, to them, to be coming from their hands.

The nature of the sensations depended on what sort of current Dr Tan applied. The simplest stimulation—a repetitive square-wave—produced an unnatural, vaguely electrical feeling. Using more elaborate patterns, though, the researchers could recreate everything from simple sensations such as pressure, vibration and tapping to more complicated feelings, as of a pen brushing lightly against the skin or of the hand rubbing across a texture.

Restoring sensation has practical uses. Modern prostheses are able, by reading electrical signals from muscles using electrodes attached to the skin of the missing limb’s stump, to perform tasks such as picking things up. Delicate tasks, however, can be tricky, since the user must rely on a combination of sight and experience to work out how much pressure to apply. For example, when Dr Tan blindfolded his volunteers and asked them to pluck the stalks from cherries without crushing the fruit, they succeeded only 43% of the time. But when he connected pressure sensors attached to the protheses’s fingers to the signal-generating machine, and gave them appropriate feedback, the success rate jumped to 92%.

Intriguingly, one unexpected benefit was that the device’s feedback banished the phenomenon of phantom limbs, in which an amputee perceives that his missing appendage is still present. Without the computer-generated sensations, both volunteers reported that their prosthetic hands felt like external tools (one described it as like an artificial hand that he was holding with his phantom hand). Switching the sensations on made the hand feel like an integral part of the body.

The main drawback of Dr Tan’s approach is that the wires to the implanted electrodes must penetrate a patient’s skin. Besides being ugly and clumsy, that opens a route to infection. As they describe in their paper, Max Ortiz-Catalan of Chalmers University of Technology in Sweden and his colleagues hope to rectify this by combining implanted electrodes with a state-of-the-art prosthetic-limb-mounting system.

Standard prostheses are held in place by a compression socket, which squeezes the artificial limb onto the stump of the natural one. That can be uncomfortable, and the socket is a constant infection risk. So Dr Ortiz-Catalan turned to a procedure called osseointegration, in which an implant is fixed directly into the patient’s bones, leaving a small, protruding metal “abutment” onto which the limb can be attached. He has managed to combine a set of implanted electrodes with a custom-built osseointegrated socket.

One advantage of such a socket is that it allows implanted electrodes to control the prosthesis, instead of relying on second-hand signals detected through the skin. That improves performance. Previously, for example, Dr Ortiz-Catalan’s patient had been unable to lift his artificial arm by more than about 80°: any further and the control mechanism got confused by electrical noise from the shoulder muscles. And Dr Ortiz-Catalan has also been able, by running current into the electrodes instead of just reading from them, to induce in his patient sensations that appear to be coming from the artificial hand.

Combining these two approaches, then, should produce a big advance in the efficacy of artificial limbs. And the subjective benefits could be just as important as the practical ones. Part of the problem of phantom limbs is that they often hurt. By abolishing the phantoms, Dr Tan’s technique also abolishes the pain. Asked about the comparison between a limb with feedback and one without, the participants were unequivocal. As one put it, “I’d rather have it in a heartbeat.”
[760 words]

Source: Economist
http://www.economist.com/news/science-and-technology/21623580-artificial-limbs-feel-real-thing-are-getting-closer-once-more

兮兮西西

Time 2 3’11’51 pufferfish is a kind of fish that looks like a circle and can puff up to be a ball when defense themselves with poision
The size color species of pufferfish
Time 3 2’58’03 the toxin of pufferfish is powerful
Japanese eats pufferfish
The toxin of pufferfish can make people coma-like just like a zombies

Time 4 2’42’98 the hawking radiation is the radiation that could escape from the black hole –proved by SHK

Time 5 2’19’10 although the experiment was full of query，a scientist named J proved hawking radiation using soundwaves in the lab

Time 6 2’ 12’73 the lab experiments connect general relativity to liangziwulixue
Physicist can use the theory to know more about gravity
Even though its not perfect, it’s the closest one than ever


O 7’22’98 there is a experiment about creating sensations to make the artificial limbs feel real
Artificial limbs’ using combines sight and experience about pressure
One unexpected benefit is the volunteers’ feedback against huanzhi
The wire must go into patients’ skin
It’s the big advance of artificial limbs

影魔摇大…

Time2:3′46″
Time3:3′51″
Time4:3′14″
Time5:3′05″
Time6:2′09″
Obstacle:7′53″
    好多单词都不认识或者不熟悉，读起来还是蛮头疼的。读着容易断片，就是只是在读句子，没精力去想理解他在说些什么了。。。。。

TVXQashley

time2 1:56
time3 2:06
time4 1:52
time5 1:51
time6 1:16

obstacle:   5:00

14/10/14

quite interesting and informed~

Yeezy

Time2: 2'06" The strange circules under water are made by pufferfish. Pufferfish has 4 teeth, which are used to eat shellfish. When met with dangers, pufferfish puff off, with water suddenly filled in its stomach. Although it is toxic, it may not kill predators such as sharks.

Time3: 2'15" Pufferfish should be properly prepared as fuju in Japnanese chefs, because the tredotoxic of pufferfish may cause people to dizz, even more seriously, it may cause prssure lowering. The zombie in H. is cause by the intredotoxic of pufferfish.

Time4: 1'29" An experments can help to mimick the H. Blackhole Theory.

Time5: 1'56" S. control the temparture to below zero to make the participle's speed lower than the speed to pass through blackhole; He also set an experiment to rebounde the participles to mimick the conditions in the universe. However, someone suspects his amplying of the experiment, he is still perfecting his experiment.

Time6: 1'12" D. think the phenoment helped to find another phenomen. F. thinks the experiment helps to find a new atom.

Obstacle: 3'30" People may feel uncomforable to have limbs. The professor from Ohio University made an experiment, showing that a sensor helped people better bend their arms. Although the approcah was doubting, the experiment has advantages, such as help people better control their limbs.

MAGGIEHE1993

哎呀还有首页~~~谢谢大洁洁~~~~~
-------------------------------------------------------------
Obstacle: One of the drawbacks of existing prosthesis is that they lacks drawbacks and people who wear them doesn't feel
          real. Daniel Tan and his colleagues succeeded in creating signals that appeared to come from prosthesis of two
          volunteers. The nature of the sensations depended on what sort of current Dr Tan applied. Restoring sensation has
          practical uses such as picking things up. One unexpected benefit of the device's feedback is that swiching the
          sensations on made the hand feel like an integral part of the body. The main drawback of Dr Tan's approach is that
          the wires to the implanted electrodes must penetrate a patient's skin and the method opens a route to infection.
          Dr Tan also improved the attachment of prosthesis to the limb. One advantage of such a socket is that it allows
          implanted electrodes to control the prosthesis, instead of relying on second-hand signals detected through the
          skin. Combining these two approaches, then, should produce a bid advance in the efficacy of artificial limbs.

gpy1992

Time 2 2'34
Scientists recently identified the culprit: a new species of prfferfish.
Time 3 2'57
Despite the risks of ingesting tetrodotoxin, pufferfish are a delicacy in mant parts of the world.
Time 4 2'28
scientists have come closer than ever before to creating a laboratory-scale imitation of a black
hole that emits Hawking radiation, the particles predicted to escape black holes due to quantum
mechanical effects.
Time 5 3'20
Time 6 2'14
Time 7 6'00
实在是太糟糕啊看的！

cherry6891

43-03
time2
The culprit of mystery circle is pufferfish,it build tiny architecture to woo females.
Time3
Elaborate preparation are needed to cook pufferfish,only licensed chefs may prepare pufferfish in Japan,even this,every year still many people die after ingesting improper prepared fish. American create a DNA library for pufferfish to control illegal  import. The powerful tetrodotoxin can make people zombie --completely paralyzed but consciously
Time4
Scientist almost create the imitation of black hole that emits harking radiation .
Time5
In the cold temperature scientists can control fluid quantum. But this test of S can only test one frequency,so he can not be sure it has harking's predicted intensity at different frequencies
Time6
The intimated history of radiation. This sonic intimation is not the perfect but closest anyone could reach.

Obstacle
Tan better the artificial limb by adding electrode around nerves of amputee stumps,by adding this patients has more feeling on prostheses.The socket allows the electrons to control the prostheses ,instead of relaying on the second hand signal detected through the skin