英语听力听写练习原文

1、英语听力听写练习原文2014.7第一集1.Ocean Plastic Particles Could Get in GillsSea creatures eat plastic dumped in the ocean, but they also might be accumulating plastic by sucking up tiny particles with their siphons and gills. Christopher Intagliata reports. There are now at least five major garbage patches in th

2、e worlds oceans, and much of that trash is plastic. But last month researchers said they can only account for one percent of the plastic theyd expect to find in the oceans. So, whered the rest of it go? Well, animals eat some of it. Plastic has been found in turtles, seabirds, fish, plankton, shellf

3、ish, even bottom-feeding invertebrates. But theres another way sea creatures might be accumulating plastic: by sucking up tiny plastic particles with their siphons and gills. Researchers added common shore crabsCarcinus maenasto tanks of seawater containing millions of tiny plastic particles, just 1

4、0 microns in diameter. After 16 hours, all the crabs had plastic lodged in their gills. And the particles stuck around for up to three weeks, too. The results are in the journal Environmental Science and Technology. Andrew J. R. Watts et al, Uptake and Retention of Microplastics by the Shore Crab Ca

5、rcinus maenas The longer plastic sits in an animal, researchers say, the better the chances it will travel up the food chain. Meaning all our plastic waste could come back to bite usor rather be bitten by us. Of course we eat mussels whole, without the shells. But were potentially eating plastic, if

6、 theyre from a site where theres plastic present. Lead researcher Andrew Watts, of the University of Exeter. We dont know how much plastic we have in our stomachs chances are we do have some. Christopher Intagliata2. Salmonellas Favorite Food Could Be Its Achilles HeelSalmonellas primary fuel source

7、 is the molecule fructose-asparagine. Starving it of that fuel in an infected person could kill it without harming beneficial gut bacteria. Karen Hopkin reports Summers here and with it come picnics, barbecues and of course salmonella. The germ is notorious for contaminating a variety of favorite wa

8、rm-weather foods. But the bacterias palate is more limited than ours. Once salmonella makes its way into your system, it relies on a single unusual nutrient to survive. Thats according to a study in the journal PLoS Pathogens. Mohamed M. Ali et al, Fructose-Asparagine Is a Primary Nutrient during Gr

9、owth of Salmonella in the Inflamed IntestineMost people tough it out when they get food poisoning from salmonella. Thats because treatment with antibiotics would eliminate the infection, but also get rid of the gut bacteria that promote good health. To figure out how to target salmonella specificall

10、y, researchers screened for genes vital for the microbes survival during the active phase of infection. And they identified a cluster of five genes that work together to allow the bacteria to digest a molecule called fructose-asparagine. No other organisms are known to use this chemical for fuel, so

11、 starving salmonella of it could be a new strategy for fighting this foodborne bug while leaving desirable intestinal inhabitants unharmed. Next, the researchers plan to see which foods contain large amounts of salmonellas go-to snack. But please, dont send unsolicited samples of Aunt Agness egg sal

12、ad. Karen Hopkin3.Education Level Linked to NearsightednessIn a German study, half of those with a university degree were myopic compared with less than a quarter of folks who quit after high school or secondary school. Karen Hopkin reports Nothing says “overeducated egghead” like a pair of coke-bot

13、tle glasses. But even clichs sometimes hit the nerd on the head. Because a new study finds that nearsightedness is linked to the number of years spent in school. The findings can be viewed in the journal Ophthalmology. Alireza Mirshahi et al, Myopia and Level of Education In the past century, the pr

14、evalence of myopiascience-speak for being able to see only whats right in front of youhas been on the rise. So much so that it cant all be blamed on geeky genes. To nail down the potential environmental influences, researchers focused on the classroom. They gave eye exams to nearly 5000 German subje

15、cts in a project called the Gutenberg Health Study. The researchers found that individuals with 13 years of education were more myopic than those who didnt get past primary school. And more than half of those with a university degree could use a set of specs, compared to less than a quarter of the f

16、olks who quit after high school or secondary school. All that learning takes a lot of reading. Which itself is associated with nearsightedness. Or the nearsighted may gravitate toward pursuits easier to seelike hitting the books. Either way, seems that being a good student may not require great pupi

17、ls. Karen Hopkin4.Give Us This Day the Bread Wheat GenomeA preliminary map of the bread wheat genome includes the locations of more than 75,000 genes. Cynthia Graber reports Wheat helped create civilization in the Middle East. Its a staple crop for 30 percent of the worlds population. And now, with

18、the publication of four articles in the journal Science, were close to a detailed understanding of the bread wheat genome. Kellye Eversole et al, Slicing the wheat genomeWheat is tough to sequence. Its gone through multiple hybridizations, making its genome five times larger than a human one. Plus t

19、here are many redundancies: more than 80 percent of the genome is made of repeated DNA sequences. So the typical whole-genome shotgun approachbreaking genomes into segments and then reassembling themdoesnt work for wheat.Instead, an international consortium devised another strategy, involving physic

20、ally mapping individual chromosomes and chromosome arms.One paper details a draft of the entire genome of bread wheat. Another identifies all the genes on the largest of the plants 21 chromosomes. Some 75,000 genes have been mapped. The methods in the second paper will help scientists map the remain

21、ing chromosomes. They say it should take another three years.Knowing exactly which genes are responsible for talents such as tolerating drought or improving yields should allow researchers to mine the genome and to quickly produce new and better wheat varieties to bring us our daily bread.Cynthia Gr

22、aber5.Supercooled Organs Could Stretch Time to TransplantLiver transplant time from human donor to patient is limited to 12 hours, but rats that got livers specially stored for three days were going strong three months later. Cynthia Graber reports If you need a new liver, doctors have about twelve

23、hours to transport it from a donor. That ticking clock severely limits the ability of doctors to get organs to patients.Now researchers have demonstrated a method that kept rat livers viable up to four days.The scientists lowered the livers to below freezing temperatures, while flooding the tissue w

24、ith antifreeze chemicals to prevent the formation of damaging ice crystals.But such cooling alone is not sufficient, due in part to the livers wide variety of cell types and functions. So the researchers also used machine perfusion: as the livers were cooled they were flushed with solutions that kep

25、t them operational. They were perfused again as they were brought back to above-freezing temps.All the rats that were implanted with 3-day-old livers survived for three months. Nearly 60 percent of the rats with four-day-old livers survived. In contrast, no rats that received 3- and 4-day-old livers

26、 preserved by currently used methods survived. Tim A. Berendsen et al, Supercooling enables long-term transplantation survival following 4 days of liver preservation, in Nature MedicineThis work is an early step toward creating a system that could work in humans, which would dramatically improve the

27、 chances of getting organs to people who desperately need them.Cynthia Graber6.Space-Based Data Collection Better Predicts FloodsSatellite data can help geologists predict major floods up to 11 months in advance in areas where snow melt or groundwater is a significant contributor. Cynthia Graber rep

28、orts Want to know whereand whenthe next major river flood will hit? Just look up, to the satellites.Conventional estimates of river volume come from rainfall, of course, and from measurement of the water that seeps from soil and groundwater reserves.But NASAs GRACE satellites, for Gravity Recovery a

29、nd Climate Experiment, can pick up changes in the gravity field in a given river basin. The more water in the basin, the higher the gravity signal.Scientists used GRACE results from 2003 to 2012 to see if they could have predicted the 500-year flooding event in the Missouri River basin in 2011. Prec

30、eding the flood were two significant storms, record snow melt, saturated soils and particularly high groundwater.With GRACE data, the researchers found that they could have predicted the Missouri River floods months before current prediction models. They say that the technique could be used to forec

31、ast floods up to 11 months before such events take place in areas where snow melt or groundwater is a significant contribution.The research was published in the journal Nature Geoscience. J. T. Reager, B. F. Thomas and J. S. Famiglietti, River basin flood potential inferred using GRACE gravity obser

32、vations at several months lead timeSnow melt and major rain storms are predicted to increase with climate change. Which puts a premium on better flood prediction.Cynthia Graber7.Mobile Phones Carry Owners MicrobiomesThe bacteria found on someones mobile phone is a good match for the most common kind

33、s of bacteria that live on their hands. Christopher Intagliata reportsThis year, the number of mobile phones on cell networks is expected to surpass the Earths population. More people now own cell phones than actually have access to working toilets. James Meadow, a microbial ecologist at the Univers

34、ity of Oregon. Hidden in the data is the reality that some people work on their phoneson toilets. If that grosses you out, consider this: So it turns out were just really leaky animals. We just, we leave our bacteria everywhere we go. Including, of course, our phones. Meadow and his colleagues took

35、a census of the bacteria on thumbs and index fingers of 17 volunteersand on their smartphone touch screens. Overall, they IDed over 7,000 types. Looking at just the most common bacteria, those that appear more than 0.1 percent of the time, they found an 82 percent similarity between the microbiomes

36、of fingers and phones. Meaning our phones are a pretty good mirror of ourselves, microbially, at least. The results appear in the journal PeerJ. James F. Meadow, Adam E. Altrichter and Jessica L. Green, Mobile phones carry the personal microbiome of their owners We have always been covered in bacter

37、ia and we will always be covered in bacteria. So the fact that our phones are also covered in bacteria is no reason for concern. In fact, the researchers say that mobile phones may hold untapped potential as personal microbiome sensors. App developers, take note. Christopher Intagliata8.Malarial Mic

38、e Smell Better to MosquitoesMice infected with the parasites that cause their type of malaria produce odorous compounds that attract mosquitoes, increasing the odds that the parasites will be spread to the next victimsGetting malaria stinks. Literally. According to a new study, malaria victims give

39、off odors that attracts mosquitoes. And the insects that feed on the infected sufferer are then more likely to spread the disease. The work appears in the Proceedings of the National Academy of Sciences. Consuelo M. De Moraes et al, Malaria-induced changes in host odors enhance mosquito attraction M

40、alaria is caused by plasmodium parasites, which are transmitted by mosquitoes. A decade ago, scientists found that Kenyan kids infected with plasmodium were more attractive to mosquitos than were kids who were parasite-free. But they did not know what drew the bloodsuckers to the unfortunate infecte

41、d children. To find out, researchers took mice that harbored the rodent version of malaria and put the animals in a wind chamber. And they found that mosquitos flocked toward the infected animals, attracted by their smell alone. By chemically analyzing the animals scents, the researchers found that

42、the parasites boost the levels of a variety of odorous compounds that attract mosquitoes. So plasmodium is manipulating both its victim and its carrier to get itself spread far and wide. The finding may help with malaria prevention: if we can mask or harness the eau d infection, maybe we could nose

43、the mosquitoes away from people. Karen Hopkin9.Professors Still View MOOCs SkepticallyA survey of professors finds that most see online courses as inferior to in-class lessons-but those who have taught online are more open to their potential. Larry Greenemeier reports.The New York Times calls 2013 “

44、the year of the MOOC.” But massive open online courses still fail to get high marks from most educators.In a recent survey of more than 2,200 professors, only one in five thought that online courses could be as effective as classroom curricula. Their biggest concern: limited interaction between teac

45、hers and students. The survey was done by Gallup and the website Inside Higher Ed.Respondents linked MOOC credibility to whether an online course was offered by an accredited school and to a students ability to receive credits.Faculty skepticism isnt surprising. New technologies often turn crafted p

46、roducts and services into bland commodities, something no teacher wants. On the other hand, resistance to change, especially when it involves computers, tends to be a losing strategy in most fields.An important wrinkle in the data: much MOOC criticism comes from faculty whove never taught an online course. Of the