【Native Speaker每日综合训练—31系列】【31-10】科技

zxppx

Official Weibo: http://weibo.com/u/3476904471
大家好!胖胖翔来了! 提前祝大家春节快乐~ 速度的第二篇有一个音频，大家可以通过source的链接打开来听听

Part I：Speaker

【Rephrase1】
Article 1
Grand Canyon May Be Older (And Younger) Than You Think

[Dialog, 3: 52]

Source:
http://www.npr.org/2014/01/27/265437261/grand-canyon-may-be-older-and-younger-than-you-think

zxppx

Part II：Speed

【Time 2】
Article 2
Fastest Mountain Erosion on Record

The Southern Alps of New Zealand are some of the fastest growing mountains in the world—but they’re also eroding quickly. Wind, rain, and a variety of natural chemical processes are breaking down rock into 2.5 millimeters of soil each year. That’s about four times the highest rate previously measured anywhere else in the world, according to a new study. Researchers tallied the figure by measuring the concentrations of beryllium-10, an isotope produced naturally when cosmic rays strike rocks at Earth’s surface, in sediments gathered from slopes and riverbeds (image). They also measured the concentration of zirconium in the samples, which helps estimate the rates of various chemical changes in the soil. Together, physical and chemical weathering conspire to bring down mountains—and typically soak up CO2 in the process, but the overall magnitude of this climate-cooling effect has been long debated. Contrary to previous studies, the new data suggest that there isn’t a “speed limit” on the rates of chemical weathering in mountain soils, the researchers report online today in Science. The disparity with previous analyses, the researchers contend, stems in large part from the environment found in the Southern Alps. With an average annual precipitation of more than 10 meters in some locales, slopes sport temperate rainforests and shrubby ecosystems that trap soil before it can wash away to the seas, where its ability to scrub CO2 from the air would cease. In many of the areas previously studied elsewhere in the world, some of them relatively arid, erosion sweeps away soil quickly—there, as a general rule, the steeper the slopes, the less time soil sticks around. The longer the soil stays in place, the more time there is for the soil to chemically interact with the atmosphere. The new results may help scientists better assess how episodes of mountain-building deep in Earth’s past have affected climate over the long term.


Source:
字数[314]
http://news.sciencemag.org/climate/2014/01/scienceshot-fastest-mountain-erosion-record


【Time 3】
Article 3
Scientist Creates Music From Voyager Space Probe Data

As the Voyager space probes plunge into the inky cosmic void, each carries a golden record with 27 songs ranging from Mozart to Chuck Berry. Now, with help from a musical physicist, the twin space probes boast a song of their own. Each craft carries a cosmic ray detector snapping hourly measurements of the number of protons whirring past them. Over the last 37 years, the probes recorded more than 320,000 such measurements. Domenico Vicinanza, a musician with a Ph.D. in physics, mapped each value with a corresponding note on the musical range, with larger counts corresponding to higher notes. Stringing and mixing the notes together, Vicinanza assembled the spacecraft’s musical score. In the song, Voyager 1 plays the piano while Voyager 2 accompanies on the string instruments. Each overlapping note during the song corresponds to the spacecraft simultaneously measuring cosmic rays while soaring through space billions of miles apart. While Vicinanza admits he composed the musical arrangement purely as a fun way to present the Voyager mission data, he says transforming data sets into music in this way can help scientists recognize trends and patterns they might otherwise miss. And that makes for music that’s definitely out of this world.


字数[201]
Source:
http://news.sciencemag.org/physics/2014/01/scienceshot-scientist-creates-music-voyager-space-probe-data


【Time 4】
Article 4
Russia's drug-resistant TB spreading more easily
Newly discovered mutations help tuberculosis to stay infectious while evolving resistance to multiple drugs.

Bacterial 'superbugs' are getting ever more potent. Tuberculosis (TB) strains in Russia carry mutations that not only make them resistant to antibiotics but also help them to spread more effectively, according to an analysis of 1,000 genomes from different TB isolates — one of the largest whole-genome study of a single bacterial species so far.

TB, which is caused by the bacterium Mycobacterium tuberculosis, exploded in Russia and other former Soviet nations in the early 1990s, after the collapse of the Soviet Union and its health system. The incomplete antibiotic regimens some patients received, meanwhile, sparked rampant drug resistance. But the latest study of TB cases in Russia, published today in Nature Genetics1, indicates that such ‘programmatic’ failures may not be the only explanation for the rise of drug-resistant TB in the region — biological factors also play a big part.

As part of a long-standing effort to study the rampant drug-resistant TB in Samara, a region of Russia about 1,000 kilometres southeast of Moscow, researchers collected TB isolates from 2,348 patients and sequenced the entire genomes of 1,000 of them. This enabled the team to identify previously unknown mutations linked to antibiotic resistance, as well as 'compensatory mutations' that improve the ability of drug-resistant TB to spread.

Nearly half of the TB isolates were multi-drug resistant, which means that they were impervious to the two common first-line antibiotics that cure most TB infections, while 16% of these isolates also harboured mutations that made them impervious to ‘second-line’ drugs. These infections are more expensive to treat, and patients who receive ineffective drugs are more likely to spread TB.

“It certainly adds an extra layer of worry, because one had assumed if you could solve programmatic weaknesses, you would solve the problem of the drug-resistant TB,” says the study's lead author Francis Drobniewski, a microbiologist at Queen Mary University of London. “But this does seem to be a biological problem as well.”

“Although we know the general story of TB drug resistance in Russia, these new findings are still shocking,” says Christopher Dye, an epidemiologist at the World Health Organization in Geneva, Switzerland. "Truly scary," he adds.


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【Time 5】


Antibiotics block essential functions in bacteria, such as making proteins or building cell walls. Mutations in the genes involved in these duties can lead to antibiotic resistance, but they also tend to make bacteria divide more slowly. But laboratory experiments have shown that bacteria can develop compensatory mutations that restore the pathogen's ability to divide quickly. Drobniewski’s team found such mutations in more than 400 isolates that were resistant to the first-line antibiotic rifampicin, and the authors suggest that the mutations might overcome the growth-slowing effect of evolving resistance.

“The worst scenario is that the organisms are developing resistance, compensating for it, and evolving into something that’s new and different, that’s much less treatable,” says Megan Murray, an epidemiologist at the Harvard School of Public Health in Boston, Massachusetts. In a 2013 study2, her team found both widespread drug resistance and compensatory mutations in their analysis of 123 TB genomes from around the world.

But even if biology is a major driver of Russia’s drug-resistant TB epidemic, public-health officials can still beat it back, says Dye. “My bet is that, if the local control programme correctly identifies strains carried by each patient, and treats them with the most effective drug regimens, then the number of resistant cases will fall,” he says. “That’s what we’ve seen in Estonia, Hong Kong, the USA and elsewhere. I doubt that Russia is different.”


字数[230]
Source:
http://www.nature.com/news/russia-s-drug-resistant-tb-spreading-more-easily-1.14589


【Time 6】
Article 5
Dogs Follow the Leader

Scientists have long puzzled over whether dogs have a social hierarchy similar to wolves (Canis lupus), their closest relatives. Wolf packs are typically made up of a nuclear family that’s led by a single breeding pair. But dogs living with human families are often placed with other unrelated dogs, and many of them may have the potential to breed. To find out if there is a leader in such groups, researchers tracked the paths of six dogs cared for by one owner as they took a series of walks. Five of the dogs were Vizslas, a Hungarian hunting breed, and one was a mixed breed. All were outfitted with high-resolution GPS harnesses (as shown in the photo above) that mapped their paths as they all traveled away from their owner and back again through an open grassy field; the owner also wore a GPS unit on her shoulder. Dogs that consistently took the lead were older, more aggressive, and more trainable than dogs that followed, the scientists report online today in PLOS Computational Biology. The scientists also determined that the leaders in this group of dogs were the most dominant. Dog leaders were followed in nearly 75% of their interactions with another dog—which is similar to the amount of time wolf pack leaders direct their followers. There is one key difference, though, between the wolf and dog leaders: While leadership in wolves is tied to an individual’s reproductive role, it apparently is not in dogs, at least not in this group. The main leader among these six was a neutered female. Thus, even without a breeding pair to direct them, the dogs in this group organized themselves into a hierarchy, and paid attention to the leader of the pack.


字数[290]
Source:
http://news.sciencemag.org/biology/2014/01/scienceshot-dogs-follow-leader

zxppx

Part III： Obstacle

【Paraphase7】
Article 6
How Farming Reshaped Our Genomes
The face of a forager. This 8000-year-old hunter-gatherer found in a Spanish cave had dark skin and blue eyes.

Before farming began to spread across Europe some 8500 years ago, the continent’s occupants were hunter-gatherers. They were unable to digest starch and milk, according to a new ancient DNA study of a nearly 8000-year-old human skeleton from Spain. But these original occupants did already possess immune defenses against some of the diseases that would later become the scourge of civilization, and they apparently had dark skin. The findings are helping researchers understand what genetic and biological changes humans went through as they made the transition from hunting and gathering to farming.

The rise of farming about 10,000 years ago was one of the most dramatic events in human history. Europe’s farmers came originally from the Middle East and migrated west via Greece and Bulgaria. For decades, the only way scientists could study these events was by extrapolating back from the genetics of modern-day Europeans, a rough guide at best to what had happened in the past. But over the past several years, ever more sophisticated techniques for extracting and sequencing DNA from ancient skeletons have opened the window on to the genetics of ancient hunter-gatherers and farmers alike, allowing researchers to not only trace their movements and interactions but also how the rise of farming changed their biology.

In June 2012, for example, a team led by geneticist Carles Lalueza-Fox of the University of Barcelona in Spain reported a complete DNA sequence from the mitochondria—the energy plant of living cells—of a hunter-gatherer skeleton discovered in 2006 at the La Braña-Arintero cave site in northwest Spain. The skeleton was one of two found in the cave, accompanied by ornaments made of the teeth of red deer, which this population apparently hunted along with other animals. This southern European genome showed striking similarities with that of a number of other hunter-gatherers in northern and Eastern Europe and suggested that early nomadic hunter-gatherers were a far more cohesive group—both genetically and culturally—than researchers had realized. The findings, some researchers pointed out, could help explain why prehistoric hunter-gatherers were able to coexist with early farmers for several thousand years before fading from the scene.

For the new research, published online today in Nature, Lalueza-Fox teamed up with ancient DNA ace Eske Willerslev of the University of Copenhagen and other scientists to completely sequence the nuclear DNA of the same La Braña skeleton. Although the new genome is a preliminary rough draft, a comparison of key genes involved in skin and eye color, diet, and the immune system with those of both early farmers and modern Europeans provides a tantalizing new picture of the changes that took place in European populations as farming took over.

One surprise is that the La Braña man had dark skin and blue eyes, a combination rarely seen in modern Europeans. Although today’s southern Europeans tend to be somewhat darker than their northern counterparts, they are still relatively light-skinned compared with Africans, an adaptation often linked to the need to absorb more sunlight and so produce adequate amounts of vitamin D. That this feature of the La Braña skeleton might have been widely shared and not just a one-off is also suggested by recent findings, as yet unpublished but posted online in preliminary form, that other European hunter-gatherers also had dark skin and blue eyes.

Lalueza-Fox suggests that prehistoric hunter-gatherers got most of their vitamin D from eating lots of meat and that natural selection did not lead to the evolution of light skin until the advent of farming and diets based more on carbohydrates. Thus meat, fish, and eggs, which make up a much higher proportion of diets today than they did for early farmers, are a major source of vitamin D in modern populations, but early farmers would have been much more reliant on sunlight to help produce vitamin D in their skin. “It seems possible that latitude is not the key factor in skin depigmentation, but diet,” he says.

Another feature of the La Braña genome is more consistent with current thinking about how farming changed human biology, however. The genes involved in breaking down lactose (the key sugar in milk products) and starch (the key nutrient in domesticated plants) were in an “ancestral” form, the team reports, meaning that hunter-gatherers were not good at digesting these foods, which later became essential to farming societies.

But the La Braña man did have some talents thought to have originated only with farming societies: His immune system was apparently capable of fighting off a number of diseases, such as tuberculosis, pneumonia, and malaria (which was endemic in southern Europe until modern times), which researchers had assumed were passed to humans from animals once cattle, sheep, and other species were domesticated. Out of 40 genes involved in immunity that the team looked at, 24 (60%) were similar to those of modern Europeans. “It appears that the first line of defense against pathogens was already there,” says Wolfgang Haak, an ancient DNA researcher at the University of Adelaide in Australia. One possible explanation, Lalueza-Fox adds, is that “epidemics affecting early farmers in the [Middle East] spread to continental Europe before they went themselves.”

Finally, the La Braña genome provides new evidence, Lalueza-Fox and Willerslev say, for the initial hypothesis that European hunter-gatherers were a widespread, genetically and culturally cohesive population long before farmers arrived, rather than a collection of isolated nomadic bands. Thus the new genome bears significant affinities with that of a 24,000-year-old child found at the Siberian site of Mal’ta, the sequence of which was reported by Willerslev late last year. This suggests, Willerslev says, that there might have been “substantial gene flow between east and west” leading to more homogenous populations than previously suspected.

Pontus Skoglund, a geneticist at Uppsala University in Sweden, says that this conclusion is supported by his own work on the ancient DNA of Scandinavian hunter-gatherers, who, although from the far north, show genetic affinities not only with the southern La Braña individual but also with the eastern Mal’ta child. “It is quite clear that we are looking at a big genetic watershed” during the transition from hunting and gathering to farming, Skoglund says, in which both genes and biology changed markedly. The farmers from across Europe “look the same” and the hunter-gatherers also “look the same, the opposite of what we would expect from geography alone.”


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Source:
http://news.sciencemag.org/archaeology/2014/01/how-farming-reshaped-our-genomes

guagua13

沙发  谢谢胖胖翔～
苏错生日快乐！！！！[]~(￣▽￣)~*

Speaker
nobody knows how old grand canyon is.
south rim: the trail of time tells the geographic time. 5-6 million years old.
erosion takes away materials --> not easy to figure out when the grand canyon was cut
actually 70million years ago
grand canyon is neither old nor young, rather it's both. as a whole is young, a couple of sections are more ancient
the next year, there will be more data and more debate

Speed
Time2: 2:33:32 314
The Southern Alps are some of the fastest growing mountains in the world, but they are eroding quickly - about four times the highest rate previously measured anywhere else in the world.
measurements researchers used to figure out the data
The results of the study may help scientists better assess how episodes of mountain-building deep have affected climate over time.
Time3: 1:25:31 201
V says he composed the musical arrangement as a fun way to present the Voyager mission data, but he says transforming data sets into music in this way can help scientists recognize patterns and trends.
Time4: 2:23:17 356
tuberculosis 肺结核
TB strains in Russia carry mutations that make them resistant to antibiotics and help them spread more effectively.
Biological factors also play a big part.
Patients who receive ineffective drugs are more likely to spread TB.
Time5: 1:35:01 230
Bacteria can develop compensatory mutations in more than 400 isolates that were resistant to the antibiotic. Organisms may evolve into something that is new and different, and much less treatable.
Strains each patient carried should be identified and treated with the most effective drugs, so that the number of resistant cases will fall.
Time6: 1:56:56 290
Dogs also have a social hierarchy and follow the leader.

Obstacle 7:30:76 1077
Hunter-gatherers were unable to digest starch and milk and possessed immune defenses against some of the diseases. What biological and genetic changes did humans go through as they made the transition from hunting to farming?
Research showed that hunter-gatherers were a more cohesive group - both culturally and genetically.
European hunter-gatherers had dark skin and blue eyes, a combination rarely see in modern Europeans. Sunlight might have been the key resource of Vitamin D for early farmers.
The author provides more details about some ideas mentioned before.

Talitha

2:2'24:314:125
-fastest grow mountain also erode at the fastest speed.
-how different chemicals cause the erosion.

3:1'22:201:147
- a Phd musician transformed data sets from the space probe into music in this way can help scientists recognize trends and patterns they might otherwise miss.

4:3'08:356:118
-TB not only resistant to multi- drugs or antibiotics, it even spreads more effectively.

5:1'38:230:143
-after TB resists to antibiotics, it may develop into something new and different. It leads to less treatable.

6:1'57:290:146
-scientists wanted to see whether dogs follow leader as wolves do.
-scientists did an experiment to find out the result.
-Dogs follow leader.
-The difference between dogs and wolves is leader wolve also leads reproductive function, whereas dog leader is very neutre.

7:7'54:1077:135:
Main idea:how farming change our genomes
-how transaction from hunting to farming has changed human.before farming, we already had some immune system to defend certain illnesses.
-The rise of farming about 10,000 years ago was one of the most dramatic events in human history.
-a team discovery  why prehistoric hunter-gatherers were able to coexist with early farmers for several thousand years before fading from the scene.
-farming changed the skin color and eye color.
-scientists explained why and how.

疏离无罪

首页，感谢PPX，苏错生快！
Speaker:There is a debate on how old Grand Canyon is.Some think that it may be younger than we think,others think that it may be older.

01:45
The Southern Alps of New Zealand is eroding quickly.The slope of the mountain may be a factor.

00:57
Scientists use data from probes to creat music.

01:34
A new discovery that tuberculosis evolve resistance to multiple drugs in Russia.

00:53
The study also found taht tuberculosis can be infectious while have antibiotic resistance.

01:23
Dogs also have a social hierarchy similar to wolves.They will have a leader who is more aggressive and stronger.

05:10
Main Idea:Farming reshape human's genomes and biology.
A study on the skeleton of  La Braña man showed that the gene and biology of ancient human changed a lot during the processs that the society was transfered from hunt-gathering to farming.
La Braña man is a drak-skin,bule-eye human and its society is a cohesive group and wide-spread on the european contient.
The dark skin means that they need toabsorb more sunlight and so produce adequate amounts of vitamin D.The color of skin is so different from that of current Europeans.The farming changes it,because the more abundant diet supply more vitamin D.
This also changed their digest system to fit new kind of diet.
The study alsp found out that La Braña man has alrady have strong immune system which is 60% to mordern human.

stacyfeng

Time 1: 03:30.60
Time 2: 02:02.76
Time 3: 03:29.43
Time 4: 02:32.13
Time 5: 03:08.46
Time 6: 09:53.37 (越障)

ieveline

Speaker
Erosion Gread canyib takes away the material,
makes it difficult to know how old Grand canyon is.


Spead
1--02:07
Soil chemically inteaxt with atmosphere with air if it stays, or took awy by erosion,
making it is difficlt to take research

2--01:17
Physicist used record from comic space to compose

3--2:25
Tuberculosis (TB) strains in Russia carry mutations that not only make them resistant to antibiotics but also help them to spread more effectively,
‘programmatic’ failures may not be the only explanation for the rise of drug-resistant TB in the region — biological factors also play a big part.

4--01:31
the authors suggest that the mutations might overcome the growth-slowing effect of evolving resistance

5--02:10
Dog leaders were followed in nearly 75% of their interactions with another dog—which is similar to the amount of time wolf pack leaders direct their followers
There is differencen too.

Obstacle--05:37
Ancient genes are comparied with modern ones to find out the trace of farming.
And west ancietn shares the similar with east.

cherry6891

Speaker: how old is the great canyon ? The canyon was actually cut about 70 million years ago
7 7:00 how the transition from hunting to farming change the genetic ?
--extract and sequence DNA from ancient skeleton of hunter-gatherers and farmers
--genome rough draft indicates that the change of skin,eye colour and immune system took place as farming take over
--only surprise is the dark skin and blue eyes,maybe they change the way the get vitamin D ,from getting it from meat to having more reliant on sunlight
--European hunter-gatherers were a widespread and culturally cohesive population long before farmers arrive cuz substantial gene flow between east and west
--geography is not the only reason lead to gene change

2 2:22 the southern Alps is fast growing and quickly eroding. Wind,rain, and chemical process is main reason to break it down

3 1;29 voyager went to cosmic void with golden record of songs.

They paly different instrument to accompany

4 2:20 superbugs TB strains carry mutations that not only make them resistant to antibiotics but also spread more efficiently

5 1:20 mutations in the genes lead to antibiotic resistance but also make bacterial divide more slowly

6 1:40 the different hierarchy between dogs and wolfs--the leadership during wolf is tired to reproductive while for dogs,they are not

mozhiwanjia

zxppx 发表于 2014-1-28 23:49
Part III： Obstacle

【Paraphase7】

掌管 6        00:10:52.50        00:26:18.20 To demenstrate the different between west and east by genome.
掌管 5        00:02:47.15        00:15:25.70 This is an experiment of Dogs, which try to find weather Dog is similar behavers as their closest relatives, wolf. But it is failed because the leader is a female.
掌管 4        00:02:53.47        00:12:38.54 Russia scientists try to use antibiotics to stop the ability of bacteria generation.
掌管 3        00:03:51.51        00:09:45.06  Russia try to find a measurement to solve the resistant of TB, which can stop the spreading.
掌管 2        00:02:33.87        00:05:53.55 Scientist sent two satlight brocasting 2 different episodes especially, as a consquent mix to become a new song which is out of this world.
掌管 1        00:03:19.67        00:03:19.67 This paragraphy mainly tell us about the speed of growing mountain in New Zealand is the fastest in the would