【Native Speaker每日综合训练—30系列】【30-02】科技

捉妖

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大家好，很高兴能在双旦之间和大家读科技文~
Science News也开始总结年度最佳科学事件，speed选择Top 1 和Top 6两个吉利的数字来围观~
我们跨过1314后，来年再见~

Part I：Speaker

Bacteria Could Be Living Structural Sensors
A soil bacterium changes its growth pattern in response to disturbances in its environment, making it a candidate to be a living system for sensing strain in materials under heavy loads. Cynthia Graber reports
[Rephrase 1]

[Dialog, 1:41]


Transcript hided

  Cells in complex organisms sometimes respond to pressure and stress by growing in a preferred direction. The phenomenon, called mechanotaxis, helps create multicellular structures such as our organs.

Now a common soil bacterium has been found to change its growth pattern in response to disturbances in its environment. And the discovery could provide a living system for testing strain in materials under heavy loads—like, say, bridges.

The bacterium in question is called Bacillus mycoides. It was first characterized way back in 1842. Much more recently, researchers in the U.K. noticed that the Bacillus had unique growth patterns on solid cultures that contained structural defects.

The scientists took a series of microscope photos of bacterial cultures on templates with a variety of defects and under different pressures. And the bacterial filaments turned a full 90 degrees in response to only 1 degree of structural distortion. The bacteria also grew towards a glass bead disturbing the culture. The research is in the journal PLoS One. [James P. Stratford, Michael A. Woodley and Simon Park, Variation in the Morphology of Bacillus mycoides Due to Applied Force and Substrate Structure]

If this technique can be better understood and manipulated, scientists might be able to develop a bacterial early warning system for our engineered environment. A big help from a small creature.

—Cynthia Graber

Source: Scientific American
http://www.scientificamerican.co ... structural-13-12-26

捉妖

Part II：Speed

Top 25 stories of 2013, from microbes to meteorites
Magazine issue: December 28, 2013

[Time 2]
Last year it was easy to choose a story to lead our annual Top 25 list. The discovery of the Higgs boson was a watershed moment, ending a decades-long quest by thousands of physicists to fully describe the subatomic realm.

This year, nothing so momentous came to pass. But science isn’t just about dramatic announcements and tremendous technical feats. Anyone who reads Science News regularly appreciates that great new insights often arise from countless little bits and pieces of new knowledge. This year, careful readers may have noticed a steady accumulation of revelations about the bacterial communities that call the human body home. It has long been known that those microbes are essential to processes like extracting nutrients from food and fighting off their less benign brethren. But this year a growing body of research demonstrated that bacteria engage their hosts so vigorously that in some situations, scientists are left wondering which party is the tail and which is the dog.

Human evolution has also produced an impressive body of new knowledge, though some of it only deepens existing mysteries. For example, the oldest hominid DNA ever analyzed linked 400,000-year-old bones from Spain not to the Neandertals that later dominated the region, but to mysterious early hominids known from sites thousands of kilometers to the east. It will probably be a few more years before anyone can explain what is becoming an increasingly controversial era of human evolution.

This year also demonstrated that big findings can be big letdowns. After a spectacular landing on Mars in August 2012, the Curiosity rover looked for elevated atmospheric methane concentrations that would have been telltale evidence for the presence of microbial life. Anything over a few parts per billion would have given us a clear choice for 2013’s top story. But Curiosity detected an average methane concentration of only 0.18 ppb, a finding that landed it in 17th place.
[316 words]

[The rest]
Science News Top Stories of 2013

1   Your body is mostly microbes
    Microbiome results argue for new view of animals as superorganisms

2   Bioengineers make headway on human body parts
    New techniques produce mimics of brain, liver, heart, kidney, retina

3    Planck refines cosmic history
    Satellite hints at slower expansion rate for universe

4    New discoveries reshape debate over human ancestry
    Relationships among early hominids disputed

5    A double dose of virus scares
    MERS, H7N9 join list of potential pandemics

6    Sleep clears the cluttered brain
    Gunk between cells is cleansed during slumber

7    High court rules against gene patents
    Justices open way for choices in DNA testing

8    Language learning starts before birth
    Babies seem familiar with vowels, words heard while in womb

9    Caffeine triggers cloning advance
    Human embryonic stem cells copied successfully

10   Carbon dioxide levels pass milestone
    Panel affirms humans’ role in warming

11 Putting kids at risk
    Parents lax on vaccinations
     
12   Voyager 1 reaches interstellar space
    Planetary probe is first to pass beyond heliosphere

13   Death of a planet hunter
    Kepler ends successful mission

14  Below absolute zero, but hot
    Lab trickery achieves negative temperature

15 DSM-5’s controversial debut
    Diagnostic manual updates disorder criteria

16  Obama unveils brain initiative
    Project to seek secrets of thinking, learning

17 Methane shortage on Mars
    Trace of gas not enough to be sign of life

18  Canine genealogy
    Competing clues confuse story of dog domestication

19  Dark energy gets more confusing
    New data raise prospect of ‘Big Rip’ destroying cosmos

20 Slain king’s bones dug up
    Richard III’s skeleton reveals fatal wounds

21 Progress made toward twin prime proof
    Surprising advance sparks flurry of work on mathematical conjecture

22 Visitor from the Oort cloud
    Comet ISON meets demise in solar flyby

23 Odd cicada history emerges
    Brood II returns better understood

24 Gift of steroids keeps on giving
    Mouse muscles stay juiced long after doping ends

25 Meteorite makes an impact
    Space rock fires a warning shot

Source:Science News
https://www.sciencenews.org/article/top-25-science-stories-2013-microbes-meteorites

Year in Review: Your body is mostly microbes
by Tina Hesman Saey 2:00pm, December 20, 2013
[Time 3]
We are not alone. Humans’ vast inner and outer spaces teem with a menagerie of microbes that stand poised to alter conceptions of what and who we are.

Traditionally, microbes have been viewed as insidious invaders that make people sick or as freeloaders in the human gut. That view is beginning to change. In 2013, scientists amassed substantial evidence that people and other animals form a unit with their resident bacteria, archaea, fungi and viruses — the collection of microbes known as the microbiome. In fact, only about 10 percent of a person’s cells are human; microbes make up the other 90 percent.

Many researchers point out that ultimately, every species is out for itself. Nevertheless several new studies argue in favor of considering animals as superorganisms composed of host and microbes. Some scientists even advocate lumping a host organism’s genes with those of its microbes into one “hologenome.”

Treating a host, such as the human body, and its resident bacteria as a unit — or at least as an ecosystem with intimately interconnected parts — offers various benefits, scientists say. The superorganism approach may help researchers better understand how diet, chemicals and other environmental factors affect health, for instance.
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[Time 4]
Everyone, including identical twins, carries a slightly different microbial mix. Strong evidence indicates that some differences stem from diet or habitat. But even mice raised under uniform lab conditions still have individualized microbiomes. In October, two groups presented research suggesting that host genes play a role in selecting which microbes are allowed to settle in and on the body (SN: 11/30/13, p. 11). Immune system genes may be especially important in screening suitable microbial companions.

People with immune system problems have more types of bacteria and fungi on their skin. New research shows that some of those microbes may contribute to eczema-like rashes. That finding supports the idea that the immune system grants visas to friendly microbes while keeping out dangerous interlopers.

Newborns rein in their own immune systems to allow bacteria to take hold, one study found (SN: 12/14/13, p. 10). Previously, researchers thought that babies’ immune systems were just too immature to control microbes. But the new work shows that in mice and human umbilical cords, blood cells carry an immune-suppressing protein that prevents defenders from fighting off beneficial bacteria.

In mice, pups of stressed moms picked up a different mix of bacteria during birth than those born tonon-stressed moms, researchers reported at the Society for Neuroscience meeting in November. Those bacteria may affect early brain development and possibly contribute to disorders such as autism and schizophrenia (SN: 12/14/13, p. 13).

A study reported in December may strengthen the link between autism and gut microbes (SN Online: 12/5/13). Caltech researchers found that mice with autism-like symptoms have a different mix of gut microbes than normal mice do. Those microbes make chemicals that leak from the intestines into the bloodstream (and perhaps the brain), producing behavioral changes. Treating the mice with the beneficial bacterium Bacteroides fragilis improved some symptoms, suggesting that altering the microbial mix might help some children with autism.
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[Time5]
Once established, friendly bacteria shield their hosts from harmful invaders and may keep the immune system from overreacting. Harvard researchers discovered that some intestinal microbes make immune-calming molecules that can help reduce the kind of inflammation that afflicts the bowels in diseases like colitis (SN: 8/10/13, p. 14).

Even friendly bacteria put their own needs first, though. Another Harvard group found that some strains of a common gut microbe called Eggerthella lenta can rob heart patients of a drug called digoxin if the bacteria don’t get enough protein from their hosts (SN Online: 7/19/13). Some microbes change chemicals in meat into artery-cloggers (SN: 5/18/13, p. 14) or cause pain all on their own (SN: 10/5/13, p. 16).

Microbiomes not only alter the biochemical milieu in individuals, but can also influence relationships between entire species. Or even the course of evolution. A study of jewel wasps, for instance, suggests that their microbiomes can prevent two species from successfully breeding with one another (SN: 8/10/13, p. 13).

Hybrid male offspring of the two species die as larvae, an effect long explained as incompatibility between the species’ genes. But when Seth Bordenstein of Vanderbilt University and his colleague Robert Brucker removed microbes from the hybrid larvae, the wasps survived. That finding indicates that microbes in the wasps’ guts and not just the wasp genes contribute to keeping the two species from interbreeding.

The microbial momentum continues to build. Ongoing research is sure to find other ways in which microbes and their hosts interact, for good and ill. “It’s not just a one-way street,” says dermatologist Heidi Kong of the National Institutes of Health in Bethesda, Md. “The microbes are doing something to us and we are doing things to our microbes.”
[288 words]

Source:Science News
https://www.sciencenews.org/article/year-review-your-body-mostly-microbes

Year in Review: Sleep clears the cluttered brains
by Tina Hesman Saey 2:30pm, December 22, 2013  

[Time 6]
Sleep showers away cellular grime that builds up while the brain is awake — just the sort of process that could have made sleep a biological imperative, scientists reported in October (SN: 11/16/13, p. 7).

People have long puzzled over the evolutionary pressures that led animals to need sleep even though it leaves them vulnerable to predators and other dangers. Rinsing off the brain and disposing of waste proteins and other gunk might help explain why sleep evolved.

Many other things that sleep does, such as strengthening memories, are important. But they are probably bonuses to the real reason that slumber is necessary, says Suzana Herculano-Houzel of the Federal University of Rio de Janeiro.

Researchers led by Maiken Nedergaard of the University of Rochester Medical Center in New York stumbled upon sleep’s cleansing function while studying how the brain disposes of waste products.

The brain pushes fluid in between its cells to flush out buildup products, such as protein pieces that form plaques in people with Alzheimer’s disease, the team had found. After training mice to sit quietly on a microscope stage, the researchers could measure the fluid flow while the rodents were awake and asleep. Space between cells increased by at least 60 percent when the animals fell asleep, allowing cerebrospinal fluid to gush in and hose away buildup. When the animals woke up, some brain cells — probably ones called astrocytes — swelled up, narrowing the crevices separating the cells.

With the drainage system clogged, waste from hardworking nerve cells begins to pile up. Sleep deprivation or damage to the irrigation system may make it impossible for sleep to fully wash away the by-products, eventually contributing to neurodegenerative dis-orders such as Alzheimer’s and Parkinson’s diseases, the researchers speculate.
[287 words]

Source:Science News
https://www.sciencenews.org/article/year-review-sleep-clears-cluttered-brain

捉妖

Part III： Obstacle

The World’s First True Artificial Heart Now Beats Inside a 75-Year-Old Patient
Posted By: Tuan C. Nguyen
[Paraphrase 7]

A 75-year-old Frenchman has just been given the gift of life as a team of surgeons have successfully completed the transplant of a revolutionary artificial heart.

The patient, so far unnamed, is reportedly recovering at Georges Pompidou European Hospital in Paris, where the 10-hour long operation was performed last Wednesday. Unlike similar devices used to keep patients alive until a donor can be identified, the “Carmat” heart is expected to operate continuously for as long as five years while enabling the recipient to resume a normal lifestyle, perhaps even allowing the person to return to work.

“We’ve already seen devices of this type but they had a relatively low autonomy,” Alain Carpentier, inventor and surgeon, told reporters, according to The Telegraph. “This heart will allow for more movement and less clotting. The study that is starting is being very closely watched in the medical field.”

Thousands of heart implants have been carried out, but Carpentier says the version he developed was the first to fully replicate the self-regulated contractions of a real heart. Inside the two-pound mechanical organ is an intricate system of sensors and microprocessors that monitors the body’s internal changes and alters the flow of blood as needed. It quickens or slows the blood flow based on the person’s activity. “Most other artificial hearts, by contrast, beat at a constant unchanging rate. This means that patients either have to avoid too much activity, or risk becoming breathless and exhausted quickly,” writes Gizmag. On the outer surface, the synthetic organ is partially made of cow tissue to reduce the likelihood of complications such as blood clots, which are common when fabricated materials come in contact with the blood. Patients who receive artificial heart transplants usually take anti-coagulation medication to minimize such risks.

The technology, which took 25 years to develop, started taking shape after the surgeon initially tested the feasibility of developing artificial heart valves using chemically-treated animal tissues as an alternative to plastic. Since then, he has obtained approval from authorities in France, Belgium, Poland, Slovenia and Saudi Arabia to conduct human trials that are expected to run until the end of 2014. If all goes well, meaning if the patients survive at least a month with Carmat systems, Carpentier will then have the means to seek regulatory approval to make them available within the European Union sometime in early 2015.

Ultimately, the litmus test hinges on whether the artificial heart’s pumps last more than a few years. Barney Clark, the world’s first heart implant patient, survived only 112 days following a milestone procedure in 1982 that replaced his failing heart with the man-made Jarvik-7 heart. The SynCardia total artificial heart, which remains the only FDA-approved heart replacement option, has made it so that patients carry on much longer, though they’d have to adjust to the burden of  ”carrying around a compressor and having air hoses going in and out of your chest,” says heart surgeon Billy Cohn in a CNN report.

Carpentier’s half-cow, half-robotic technology takes a different approach, as compared to SynCardia’s air compression method, in utilizing a hydraulic fluid to facilitate the movement of blood. A comprehensive report in MIT Tech Review explains how this mechanism works:

    “In Carmat’s design, two chambers are each divided by a membrane that holds hydraulic fluid on one side. A motorized pump moves hydraulic fluid in and out of the chambers, and that fluid causes the membrane to move; blood flows through the other side of each membrane. The blood-facing side of the membrane is made of tissue obtained from a sac that surrounds a cow’s heart, to make the device more biocompatible. ‘The idea was to develop an artificial heart in which the moving parts that are in contact with blood are made of tissue that is [better suited] for the biological environment,’ says Piet Jansen, chief medical officer of Carmat.”

The device, powered by rechargeable lithium-ion batteries and worn on the outside, is about three times heavier than a human heart, which will limit its compatibility to 86 percent of men and 20 percent of women. However, Carpentier plans to develop smaller versions for women of smaller stature.

The Carmat artificial heart is expected to cost about 140,000 to 180,000 Euros (or $191,000 to $246,000).
[709 words]

Source:Smithsonian
http://blogs.smithsonianmag.com/ideas/2013/12/the-worlds-first-true-artificial-heart-now-beats-inside-a-75-year-old-patient/

小鱼上树

妖妖~

30-02

Speaker

If we get better understanding about how the bacteria’sformation is affected by the stress, we may use it as an early warning systemfor engineering environment.

2 316 1min50

This year is all about great new insights often arise fromcountless little bits and pieces of new knowledge. Big findings can be bigletdowns.

3 191 1min17

We are not who we are. Only 10% of our cells are human. Thisfinding helps to explain a lot

4 312 1min27

5 288 1min19

Even friendly bacteria put their own needs first-Themicrobes are doing something to us and we are doing things to our microbes

6 287 1min46

If sleep leaves us vulnerable, why we still need to sleep-itwill strengthen our memories and wash out the by-product

shannii

1.52 ／ 1.25／  2.06  ／1.55 ／1:30 ／ 06:09

kimwang53

为什么是1314？               

2.22
1.23
2.18
1.55
1.56

疏离无罪

占～～～～
Speaker:Bacteria can response to the distortion of the enviornment which can help scientists develop a early warning system for our enviornment.

01:35
There is no so momentous things came out as last year,but great new insights often arise from countless little bits and pieces of new knowledge.List some finds in 2013.

01:11
Most of human body is made up by microbes.animals are superorganisms composed of host and microbes.

01:48
The host genes play an important role in selecting which microbes are allowed to settle in the body.And these microbial mix can affect animals in many aspects.

01:47
Friendly bacterias can shield their host from invaders,but they still meet their own need first which may be harmful to human.Microbes can even affect the entire species.

01:59
Sleeping has cleaning function other than some already known functions.

04:23
Main Idea:a new kind of artifical heart
Recently a patient was surgened and replaced his heart by an artfical one.This artifical heart is so powerful that can even make him go back to work.Unlike former artifical heart,this one was made of both cow tissues and robotic technology,and can change its beat rate with activity.
The problem now is whether this artifical can work for several years.An report explain its mechanism and think that it may work for several years.
If this patient can really survive for years,this technology can be applied in EU.
However,this is for rich people.

yinghua9122

哇！！！！是不是我还在首页~~~~
谢谢楼主~~~~
Time 2
Some big inventions or discoverys in Science in 2013, like the miscrobes and landing on Mars. Although there is no momentous things in 2013, but small accumulation is the basis of the tremendous feats. At last, the author list the Top 25 discovery in this year's science field.
Time 3
Bacteria is traditionally regareded as the bad things, but scientists have found evindences that bacteria are teem with body, and they have vital effect on our body and behavior.
Time 4
The effect of the bacteria, it has influence on the mental disorder, which can be used to help autism children; immune system sometimes will protect benefical bacterica.
Time 5
Friendly bacteria can help hoster to prevent invaders, and bacteria affect not only the individual but also whole spieces. But in some situation, bacteira will compete with the hoster for the nutrients, and they priority satisfy themselves.
Time 6
When people is sleeping, brain is active to clear up grime and other waste fragment, when this clearing prosess is stopped or clogged, many psychological diseases happens.
Obstacle
Surgeons have successfully put a artificial heart into a 75-year-old man. This heart is unique from other before, it is a hybrid of cow-tissue and robot, but it's so heavily that  limit its use.

sherlock1992

Speaker:
a common kind of bacterium can change its growth pattern in response to disturbances such as pressure, stress, etc, in its environment.
such small creature can do a contribution to the bacterial early warning system in the area of engineered environment.

Speed:
2'20''
3'35''<the rest>
1'10"
4'11''
2'12''

Obstacle-4'23''
A revolutionary artificial heart has been successfully transplanted into a patient by a team of surgeons from Frech. Their aim is to free the patient from hospital and to allow him back to work.  Compared with past cases of heart implants, this time, this team fully replicate the autonomic contractions of a real heart. This kind of heart implants takes shape when the surgeon start trying animals issues instead of plastic as the material of artificial heart. The time that this artificial heart could last is the only criterion to judge the feasibility of this heart. If all goes well, C can earn the approval of EU to promote this product. But this price of this product is pretty high.

peby1223

感谢分享，已阅~