【Native Speaker每日综合训练—38系列】【38-13】 科技

cherry6891

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PartI: Speaker

Body's Pain Perception Mapped for First Time

Pain is an immediate attention getter. And when we’re in pain, we think we know the exact location of the source of that pain, for example, your knee or your back. But our ability to pinpoint pain varies across the body, and in a specific pattern.

　
Scientists created stinglike discomfort on the surfaces of volunteers’ bodies using two lasers. They measured the minimum distance between the two pain points where the volunteer could still distinguish between the two stings. And they found that this capacity to discern different pain points, called spatial acuity, improves as we move towards the center of our bodies. For example, we’re better at detecting the two pain points on the shoulders than at the wrists.

　
The scientists also tested our acuity for touch, assuming it might be similar to pain. While we tend to have an equal ability to detect touch and pain, scientists found that our acuity for simple touch decreases towards the center of the body. So in this case it’s harder for us to detect non-painful touch at our shoulders than at our wrists.

The exception to this rule of thumb, if you will, is our fingers. The digits are sensitive to both pain and touch. But it’s not because fingers have more nerve fibers. The researchers think it might be a question of information processing. Because we use our fingers constantly, we’re more practiced at sensing them. Whether they’re playing the piano, or hammering a nail.

Source:
http://www.scientificamerican.com/podcast/episode/body-s-pain-perception-mapped-for-first-time/
【Rephrase  1:45】

cherry6891

Part II: Speed

Earliest skeletal animals were reef builders
Ecological reef-building adaptation in skeletal animals
appeared much earlier than previously thought.

Time2
Animal reef-building evolved millions of years earlier than previously thought, researchers report today in Science1. Scientists have discovered fossils indicating that animal, or metazoan, reefs date to as far back as about 548 million years ago, some seven million years earlier than previously estimated. This suggests they appeared prior to the Cambrian explosion, a wellspring of diverse life that is generally thought to have driven the proliferation of reef-building.

“This succession of rocks that we’ve been looking at in Namibia encompasses a period of time important in animal life,” says Amelia Penny, a geologist at the University of Edinburgh, UK, and first author of the study. “As far as we know, these are the earliest animal building reefs.” The scientists found the fossils in Nama Group rocks, a series of layered carbonates and silicates deposited in an ancient ocean that covered what is now Namibia, hundreds of millions of years ago.
Palaeontologists estimate that microbial reefs date back at least three billion years, followed by animal reef-makers around the time of the Cambrian explosion. Animals' so-called skeletal reef building entails the deposition of shells made of calcium carbonate, while microbial reefs typically consist of cyanobacteria and other microorganisms.

What Penny and her colleagues show is the ecological evolution from one to the other, says Guy Narbonne, a palaeobiologist at Queen’s University in Kingston, Ontario. Narbonne says the discovery shows for the first time that both microbes and skeletal animals contributed to reef-building in the Ediacaran, the geologic time period immediately preceding the Cambrian. “The question we have now is how big those relative roles were and how that changed,” he says.[365]

Time3
Strong foundations
The reefs were made of tiny, filter-feeding animals known as Cloudina, a widely studied animal that lived prior to the Cambrian explosion. The authors identified key characteristics in clusters of the reef-makers: To build a reef, the animals must have a base to start from (such as the ocean floor), a way of attaching to one another and the ability to form a rigid structure.

“Modern-day reefs are a result of ecological pressures,” says geologist and study co-author Rachel Wood, also at the University of Edinburgh. Reefs typically help to protect the animals that create them from predators and they provide a means to harvest nutrients from the water. The study suggests that these natural selection pressures were in operation earlier than researchers previously thought, she says.

The discovery will drive researchers who study ancient reef-builders to look back beyond 540 million years ago for other signs of skeletal reef ecology, says Mary Droser, a palaeobiologist at the University of California, Riverside.

Meanwhile, Penny and her colleagues are constructing a three-dimensional model of the reef from slices of rock brought back from their field site to further scrutinize the Cloudina reef. With the help of international collaborators, the authors plan to study the geochemistry of the rocks to understand how the oxygen content of ancient oceans changed over time — and how this affected animal evolution. “We don’t fully understand how one affects the other,” Wood says, noting the possibility that the changing of availability of oxygen could have driven the evolution of complex life. [254]
Source:
http://www.nature.com/news/earliest-skeletal-animals-were-reef-builders-1.15470

A new view of dinosaurs, a clearer view of lunar origins

Time4
Dinosaurs have undergone any number of scientific makeovers in the last few decades. When I was young, they were depicted as lumbering, over-sized lizards, “cold-blooded” and drab. That simplistic image was eventually replaced with a more vibrant one. The velociraptor à la Jurassic Park was agile, quick, birdlike — and quite possibly festooned in feathers. Bright colors (though maybe not Barney purple) and rich social lives have also been proposed.

Scientists’ latest look at dinosaurs offers up another revision. As Meghan Rosen describes in "Dinosaurs had middling metabolisms," the new work compares dinosaur growth rates, estimated from fossils, with growth rates from modern animals for insights into dino metabolism. Energetically, dinosaurs were neither fowl nor lizard, but something in between, the researchers conclude. Like today’s sea-faring tuna and great white sharks, dinos share some traits with both ectotherms (what people mean when they say “cold-blooded”) and endotherms (“warm-blooded”).

In science, revisionism can be a good thing. Finding ways to test assumptions and accepted truths can lead to insight and discovery. As Tina Hesman Saey reports in "Human-ape split gets an earlier date," for example, the latest DNA studies of chimpanzees are forcing a rethink of just how long ago chimps and humans shared a common ancestor. And despite popular thinking that the Internet can be harnessed to power good causes, one of the first long-term scientific studies of giving in a major online movement reveals far more “slacktivism” than activism, Bruce Bower writes in our feature story "Token Gestures." At the same time, other new experiments suggest ways to motivate the public to action.

Of course, science also confirms what we think we know. Take the origin of the moon. The best theory holds it formed after a planet-sized object collided with a young Earth. The resulting explosion created the moon, which would have been chemically distinct from Earth. But chemical analyses of lunar and terrestrial rocks revealed no differences. Now, a more precise comparison of the rocks has found distinctions that support the leading theory, Rosen reports in "Rocks' chemistry reveals details of moon's origins."

Testing, revising, substantiating: That’s just what science is supposed to do.[356]
Source:
https://www.sciencenews.org/article/new-view-dinosaurs-clearer-view-lunar-origins

Biosafety in the balance
An accident with anthrax demonstrates that pathogen research always carries a risk of release — and highlights the need for rigorous scrutiny of gain-of-function flu studies.

Time5
The news last week of an accident involving live anthrax bacteria at the US Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is troubling. Some 84 workers were potentially exposed to the deadly Ames strain at three CDC labs. But the incident will cause much wider ripples: it highlights the risks of the current proliferation of biocontainment labs and work on dangerous pathogens. If an accident can happen at the CDC, then it can happen anywhere.

Details are sparse, but it seems that the anthrax was being inactivated in a biosafety-level-3 (BSL-3) high-containment lab so that it could be studied at the three BSL-2 labs. But live bacteria survived the inactivation step, and were not detected before samples were sent out. The CDC considers the risk that the exposed workers have been infected to be low, and all have been offered protective antibiotics.

Such lab accidents are fortunately not commonplace. A CDC analysis in 2012 reported, for example, that there were 727 incidents of theft, loss or release of Select Agents and Toxins in the United States between 2004 and 2010, resulting in 11 laboratory-acquired infections and no secondary transmission (R. D. Henkel et al. Appl. Biosafety 17, 171–180; 2012). Anthrax is contracted by direct exposure to spores, and does not spread between people. Much more potentially dangerous are lab accidents involving agents that do. It is impossible to read about the CDC incident and not breathe a large sigh of relief that it did not involve a novel engineered pandemic influenza strain.

Groups led by Ron Fouchier of the Erasmus Medical Center in Rotterdam, the Netherlands, and Yoshihiro Kawaoka of the University of Wisconsin–Madison created a storm in late 2011 when they artificially engineered potentially pandemic forms of the H5N1 avian flu virus. In January last year, researchers ended a voluntary 12-month moratorium on such gain-of-function flu research, which can increase the host range, transmissibility or virulence of viruses (see Nature 493, 460; 2013), and work resumed.[332]

Time6
This month, Kawaoka’s group reported that it had engineered a de novo flu virus from wild-avian-flu-strain genes that coded for proteins similar to those in the 1918 pandemic virus (T. Watanabe Cell Host Microbe 15, 692–705; 2014). The researchers were able to make a virulent version that could transmit between ferrets, and they concluded that a 1918-like virus could therefore emerge from wild avian flu viruses.

In the century since the 1918 flu hit, no similar pandemic variant has emerged despite wild animal flu viruses mutating and reassorting incessantly. The 1918 H1N1 virus was reconstructed in 2005, but human immunity to it became widespread following the 2009 H1N1 pandemic. There are no mammalian-transmissible 1918-like avian flus in the wild; the only ones that exist are Kawaoka’s team’s engineered strains.

Researchers such as Kawaoka and Fouchier argue that by engineering mutant viruses in the lab, they can identify mutations and traits that allow the pathogens to spread between mammals. This in turn, they argue, allows assessment of the pandemic potential of animal-flu viruses. In the long term, such experiments could help to elucidate the mechanisms of virus transmissibility and pathogenicity. But their shorter-term public-health benefits have been overstated. The risks and benefits must therefore be carefully weighed, and rigorous oversight is needed to ensure that such work is done only at facilities with the highest standards of biosafety.

Other scientists argue that the concept of predicting the pandemic potential of flu viruses from mutations, although appealing, is simplistic. They say that the identified mutations are but a handful out of millions of possible combinations, many of which might also allow mammalian transmission. They argue that mutations in specific proteins cannot reliably predict traits, and that outcomes depend on interactions between various other background genetic changes throughout the virus. [298]
Source:
http://www.nature.com/news/biosafety-in-the-balance-1.15447

cherry6891

Part III: Obstacle

Online causes may attract more clicks than commitments
The Save Darfur Cause on Facebook had all the makings of a slam dunk cyber success. More than a million people joined the social media site’s digital movement a few years ago to save the people of Sudan’s Darfur region from mass slaughter.   

There was a hitch in Facebook’s humanitarian giddy-up, though: The vast majority of people who enlisted in the Save Darfur Cause recruited no one else to the digital crusade and contributed no money. The sum total of their support amounted to a computer click.
“Facebook conjured an illusion of activism rather than facilitating the real thing,” sociologist Kevin Lewis of the University of California, San Diego says about the Save Darfur campaign.

While the effort managed to raise nearly $100,000 after almost three years, the money came from less than 1 percent of the 1.2 million Save Darfur members. Fundraisers and serious activists call the horde of nondonors “slacktivists,” people with an activist’s righteous intentions but a slacker’s lack of follow-through.

Lewis and his collaborators analyzed records of donations and recruits at the Save Darfur Cause. Their findings, published February 18 in Sociological Science, provide the first long-term look at the donation habits among members of a massive online social movement. Lewis conducted the study with psychologist Kurt Gray of the University of North Carolina at Chapel Hill and political scientist Jens Meierhenrich of the London School of Economics and Political Science.

Taken together with other recent experiments, this exposé of slacktivism among digital do-gooders suggests a need to rethink the potency of online awareness campaigns. Whether cruising Facebook or ambling down a crowded street, people gravitate toward slacktivism when others can see their minor act of support for a cause, researchers find. Impressing others with a public but trifling display of civic-minded concern may be all most people are willing to muster, at least those who don’t have a burning passion for a cause.

Charitable organizations that encourage people to wear pins, bracelets or other ornaments as a first step toward becoming a donor or volunteer also may need to revise that strategy, researchers say.

Still, some forms of online activism undoubtedly succeed. An online network of protesters played an important role in defeating proposed federal legislation to regulate the Internet in 2012. Facebook and Twitter users also have helped coordinate mass real-world protests against authoritarian regimes, as in the 2011 Egyptian uprisings.

Many social scientists assume that online social networks enhance all types of social and political activism, says Stanford University sociologist Sarah Soule, a deputy editor at Sociological Science. But little research has addressed that issue. Some studies of face-to-face encounters have indicated that individuals are more likely to carry out a large request after first consenting to a small request. In contrast, other investigations find that token acts of support provide an excuse for doing nothing more.

Even less is known about whether pop-up Internet humanitarian campaigns, such as this year’s #bringbackourgirls movement to rescue more than 200 kidnapped Nigerian girls, kindle successful activism.

“In the case of the Save Darfur Cause on Facebook, Lewis and his colleagues show that the effects of online activism were pretty minimal,” Soule says. Whether Save Darfur’s disappointing results represent an exception or the rule for digital movements will remain unclear until other online campaigns are evaluated.

Cause without effect
Meierhenrich wasn’t sure what to expect to learn about Save Darfur when he began to delve into its members’ online activities in 2009.
That investigation grew out of a larger project Meierhenrich had organized to probe the recruiting and money-raising prowess of the Save Darfur Coalition, a worldwide alliance of more than 190 advocacy groups founded in 2004. Shortly after that time, Facebook gained popularity among charitable organizations as a tool for attracting recruits and donations.
Some writers and Internet gurus touted social media as a game changer for activism; others doubted that digital connections made any difference. But their arguments rested on anecdotes, not investigations.

Meierhenrich responded to the debate by calling on Lewis and Gray to help him analyze donation and recruitment records for Facebook’s Save Darfur members from May 15, 2007 — the day the online movement was founded — to January 27, 2010.

During those 989 days, nearly 1.2 million people joined the Save Darfur Cause on Facebook. Of that number, about 81 percent were recruited by other members. The rest signed up independently.

Meierhenrich, Lewis and Gray focused on the 1,085,463 members who joined within the first 23 months, so that those who wanted to recruit and give money had enough time to do so. A total of 1,082,858 members — 99.76 percent of the sample — never donated a cent. That left a smidge more than 2,600 members who forked over some dough. Almost 95 percent of that select group gave only once.

About 72 percent of members recruited no one else into the online movement. Of those who did, nearly half recruited only one other person. Members knew they could recruit as many people to the cause as they wanted, but they weren’t prompted to do so on the site. In other words, a tiny number of what the researchers call “hyperactivists” breathed life into the Save Darfur Cause. The most active recruiter corralled 1,196 new members. The top donor gave $2,500 in a series of payments.

Overall, the top 1 percent of hyperactivists were responsible for 47 percent of the funds raised and 63 percent of the movement’s members.
By late 2009, donations had fallen to near zero and few new members were being recruited. What had burst on the scene as a viral movement of voluntary recruiters and donors petered out within about two years. “More and more people did less and less,” Lewis says. Occasional fund-raising e-mails sent to members had no impact on those overall trends, he adds.

As a result, donations to the online effort fell far short of the more than $1 million raised in 2008 by the Save Darfur Coalition through direct-mail solicitations.      
  
Getting to engagement
Not all online movements trigger a tsunami of slacktivism. Social media can inspire mass activism when lots of people have a direct stake in a cause, as occurred during recent uprisings against authoritarian rule in Arab countries, says sociologist Zeynep Tufekci of the University of North Carolina at Chapel Hill. About half of 1,050 Egyptian protesters surveyed shortly after that nation’s president resigned in 2011 said that they used social media to communicate about the demonstrations, especially through Facebook, Tufekci and a colleague reported in the April 2012 Journal of Communication.[1098]
source:
https://www.sciencenews.org/article/online-causes-may-attract-more-clicks-commitments

小蘑菇开始打怪

来得早不如来得巧！~
---------------------
谢谢Cherry~~

speaker:

people can point out where the pain from, the sense improves as we move towards the center of our bodies

we can feel the touch as well but the sense decreases towards the center of the body

we can have accurate reaction of our fingers just because we use them constantly

time2:

scientists have discovered fossils indicating that reefs may be the earliest skeletal animals

scientist also shows the ecological evolution from one kind of animal to other

time3:

the discovery will drive researcher to look back for other signs of skeletal reef ecology

scientists use 3D model and other tech to study how the oxygen content of ancient oceans changed over time

time4:

the new finding about dinosaurs

finding ways to test assumptions and accepted truths can lead to insight and discovery

other example of how scientists use new method to check old assumption

time5:

the affair highlights the risks of the current proliferation of biocontainment labs and work on dangerous pathogens

the CDC considers the risk is low

the number of the accidents is small

time6:

the concept of predicting the pandemic potential of flu viruses from mutations is simplistic

time7:

the online activities can attract some attentions but little of them actually donate money

the cause gives feedback to the social media which benefit a lot from the activities

the donation falls recent years

疏离无罪

先占着，不知道回来有没有被删

Speaker:Our ability to pinpoint pain varies across the body.Our ability to discern different pain point improved towards the center of our body.And our ability to detect non-painful touch decreased towars our center of body.

01:17
Scientists found that the earliest skeletal animals are reef builders and appeared much earlier than they have estimated..

01:00
The reefs were made of tiny animals known as Cloudina.Reefs help to protect the animals that create them from predators.Scientists would look back to much earlier period to study reef ecology.

02:05
Dinosaurs are something between ectotherms and endotherms.The new evidence showed that the moon was part of the earth before.

01:38
A recent lab accident raise the biosafety issue again.And similar accidents have happened a lot in the USA in the past.

01:34
The study of pandemic potential of flu viruses from mutations can be helpful in long term.But it may be risk if the biosafety is not assured.

05:43
Onlince causes just can attract people's click.Only 1 percent of them will denoate money for the issue.The new research about The Save Darfur Cause on Facebook showed this result.But some forms of activism really succeed in some aspects.
Online social networks enhance all types of social and political activism.Thought these activisms may have great impacts,it has little effect on the cause itself.
Social media can inspire mass activism when lots of people have a direct stake in a cause.

小麦爱自由

Time2 1:35
Time3 1:15
Time4 2:09
Time5 1:54
Time6 1:52
Obstacle 5:12

ffffionabear

cherry妹纸辛苦~~占座\(^o^)/~~妹纸你也很早好么~~

————感谢！！！嘿~你的作业~不，是你的作业~(￣_,￣ ) ~~~#作业天天见~~#~~~进击的阅读小分队~~~\(^o^)/~——————————————————
[speaker]咦~~好像听过的样纸
Actually we can barely define non-painful touch at different pain point because they have different lever of pain perception.What's more,we also distinguish different degree of pain depend on where we feel them.
[speed]
2'08
Scientists found the animal evolved reef building millions of years earlier than previous thought.
1'47
To build a reef,the reef maker must have something to base on,which means they need a strong foundation to one another to form a rigid structure.Scientists don't fully understand the link among level of rock,oxygen in ocean and animal evolution.
2'32
The dinosaurs share some traits with both ectotherms and endotherms,they are neither fowl nor lizard,but something in between.That kind of revisionism is good for science evolution.Testing,revising and substantiating is the core of sciencific spirit.
2'34
Although accidents in lab are not commonplace,it highlights the risks of the biosafty----those toxic virus are so close to us.
1'50
Some scientists believe they can identify mutation and trait by engineering mutant virus in the lab while others argue that the outcomes are depend on interactions between various factor,the trait they predict in lab would be just one of them.
[obstacle]
5'46
main idea:The Internet humanitarian activities are probably caused by slacktivism----people tend to impress others with public but do not want to pay too much attention for it,so they muster on Internet and "click".
effects:Those online activities have nearly no realistic effect.People who participate in the online activities usually don't donate at all.
solution:However,the online movement is still effective to social media.   

cherry6891

安安早~~~~~好早~~~~~

time2
reef-build is early than previously thought
researchers estimated it happened before Cambrian

time3
strong founfdations to approve the conclusion--the reef consist of the filter feeding animal which lived prior to the Cambrian

author plan to learn geochemical to know how affected animal evolution

time4
3 example to illustrate how science develop: testing-revising-sustantiating
new look of dinosaurs: a middle metabolism animal which is between fowl and lizard in energenetically

human-ape splited earlier,   more proofs back up the leading theory of the origin of moon

time5
the accident with anthrax demonstrates the problems of biosafety
the accident of theft, lost of select agents cause lab-acquired infections

time6
the research of flu which may form the mutations that spread between mammals should be done at facilities with the highest standards of biosafety

obstacle:

MAGGIEHE1993

还有首页~~~~~~~~~~~~谢谢cherry~~~~~~~~~~~~
----------------------------------------------------------------
Speaker: Pain is an immediate attention getter. Scientists have found that our pinpoint for pain varies accross the body.
         They used lasers to detect the pinpoint of the pain. They have found that the spacial acuity improves as the
         pinpoint moves towards the center of bodies. However, the acuity for touch decreases as the pinpoint moves towards
         the center of bodies. Fingers are exceptions and scientists think that it is because fingers have imformation
         processing systems and are used more constantly.
time2: 2min
       Animal reef-building evolved millions of years earlier than previously thought, researchers report today in Science1.
       The succession of rocks that they've been looking at in Namibia encompasses a period of time important in animal life.
       What Penny and her colleagues show is the ecological evolution from one to the other.
time3: 1min 48"
       The reefs were made of tiny, filter-feeding animals known as Cloudina, a widely studied animal that lived prior to the
       Cambrian explosion. Modern-day reefs are a result of ecological pressures and reefs typically help to protect the animals
       and provide a means to harvest nutrients from the water. The scientists plan to further study the geochemistry of the rocks
       to understand how the oxygen content of ancient oceans changed over time.
time4: 3min 02"
       Dinosaurs were once depicted as lumbering, over-sized lizards, "cold-blooded" and drab. But recently scientists have provided
       another revision of dinasaurs that they had middling metabolisms. In science, revisionism can be a good thing. Finding ways to
       test assumptions and accepted truths can lead to insight and discovery. The author gave two examples, the latest DNA studies of
       of chimpanzees and the study of the origin of the moon.
time5: 2min 44"
       The news last week of an accident involving live anthrax bacteria at the US Centers for CDC in Atlanta, Georgia, is troubling.
       Such lab accidents are fortunately not commonplace.
time6: 2min 24"
       This month, Kawaoka's group reported that it had engineered a de novo flu virus from wild-avain-flu-strain genes that coded for
       proteins similar to those in the 1918 pandemic virus.

醒醒Shine

[speaker]
ability to pinpoint pain, vary, specific pattern
[time2]
1 found: reef earlier 7m than thought,before Cambrian explosion
2 importance: both microbes, skeletal animals contributed to reefbuilding
[time3]
3 how: ecological pressures
4 what's next: oxyen change--- evolution of complex life
[time4]
1 discovery: dinosaur, both traits in cold-blooded and warm-blooded
2 revision is good
3 confirm is good too
4 conclusion: test,revise,substantiate, all good to science
[time5]
1 accident: bacteria, CDC, wider ripples,details
2 not commonplace,example, H5N1 had to end
[time6]
3 K and F: biosaftey, should carefully weighed,rigorous oversight needed
4 others : too simplistic, not reliably predict traits
[obstacle]
1 online campaign Save D,get lot people enlist,but not get much money, just clicks
2 conclusion:  people with an  activist's righteous intentions but a slacker's lack of follow-through, still some forms succeed.
3 cause without effect: describe details about Save D. lots menbers but litthle donations
4 imply: can inspire mass, when direct stake in a cause


muster:聚集支持，召集士兵to try to produce as much of a feeling such as enthusiasm or determination as you can;  a group of people brought together in one place, especially soldiers
righteous：正直的，正派的
slacker:someone who tries to avoid working 偷懒的人