Is GM Food Safe To Eat ?Traditional plant breeding involves crossing varietiesof the same species in w ays they could crossnaturally. For example, disease-resistant varieties of wh eat have been crossed with high-yield wheat to combine these properties. T his type of natural gene exchange is safe and fairly predictable.Genetic engineering ( GE) involves exchanging genes between unrelated spe cies that cannotnaturally exchange genes with each other. GE can involve the exchange of genes betweenvastly different species— e.g. putting scor pion toxin genes into maize or fish antifreeze genes into tomatoes. It is po ssible that a scorpion toxin gene, even when it is in maize DNA1, will still g et the organism to produce scorpion toxin— but what other effects may i thave in this alien environment? We are already seeing this problem — addi ng human growth hormone genes to pigs certainly makes them grow — but i t also gives them arthritis andmakes them cross-eyed, which was entirely un predictable.It will be obvious, for example, that the gene for human intelligence will n ot have the sameeffect if inserted into cabbage DNA as it had in human DNA — but what side-effect would ithave? In other words, is GM food2 safe to ? The answer is that nobody knows becauselong-term tests have not been carr ied out.Companies wanting a GM product approved in the UK or USA are required to provide regulatorybodies with results of their own safety tests. Monsanto’s3 s oya beans were apparently fed tofish for 10 weeks before being approved. Th ere was no requirement for independent testing,for long-term testing, for te sting on humans or testing for specific dangers to children or allergic4 peopl e.The current position of the UK Government is that"There is no evidence of l ong-term dangersfrom GM foods."In the US, the American Food and Drug Ad ministration5 is currently beingprosecuted for covering up research that sug gested possible risks from GM foods.A consistent all-over tan may be impossible to achieve because some body areas are much more resistant to tanning than others, a study has found.Researchers - funded by the Medical Research Council (MRC) - at the University of Edinburgh say the results explain why some holidaymakers find it so hard to achieve an even tan all over their body.The findings, published in the journal Experimental Dermatology, show that the buttock is much more resistant to sunshine but surprisingly when it does go red it tans less well than other areas.It was also found that people with no freckles tanned more easily than those without freckling.The study represents the first time that the depth of a person's tan, and not just skin redness, has been quantified.Scientists carried out the study to try and solve the puzzle of why different types of skin cancer tend to be found in different parts of the body, given that they are all caused by exposure to sunshine.The team aimed to identify whether this is linked to variations in the way different parts of the body develop a tan.The team analysed the skin of 100 volunteers, who were exposed to six dose of UVB on two areas of their body their back and their buttock.The volunteers were given an injection to minimise the rush of blood that naturally occurs after the skin is exposed to sunlight within the first 24 hours.Researchers say this redness is often confused with the start of tanning, but in fact is the skin's signal that it has been damaged.After seven days, the volunteers' skin was analysed to find what colour remained after the redness had died down. This colour recognised as a suntan comes from the skin's production of melanin, a defence that blocks the skin absorbing too much harmful UVB radiation.Jonathan Rees, Professor of Dermatology at the University of Edinburgh, who led the study said: "One A consistent all-over tan may be impossible to achieve because some body areas are much more resistant to tanning than others, a study has found.第三章New findings from the Monell Center reveal that weight gain of formula-fed infants is influenced by the type of formula the infant is consuming. The findings have implications related to the infant's risk for the development of obesity, diabetes and other diseases later in life. "Events early in life have long-term consequences on health and one of the most significant influences is early growth rate," said study lead author Julie Mennella, Ph.D., a developmental psychobiologist at Monell. "We already know that formula-fed babies gain more weight thanbreast-fed babies. But we didn't know whether this was true for all types of formula."While most infant formulas are cow's milk-based, other choices include soy-based and protein hydrolysate（水解物）-based formulas. Protein hydrolysate formulas containpre-digested proteins and typically are fed to infants who cannot tolerate the intact（完整的，原封不动的）proteins in other formulas.In adults, pre-digested proteins are believed to act in the intestine（肠）to initiate（创始，发起）the end of a meal, thusleading to smaller meals and intake of fewer calories. Based on this, the authors hypothesize that infants who were feeding protein hydrolysate formulas would eat less and have an altered growth pattern relative to infants feeding cow's milk-based formula.In the study, published online in the journal Pediatrics, infants whose parents had already decided to bottle-feed were randomly assigned at two weeks of age to feed either a cow's milk-based formula (35 infants) or a protein hydrolysate formula (24 infants) for seven monthes . Both formulas contained the same amount of calories, but the hydrolysate formula had more protein, including greater amounts of small peptides（多肽类，缩氨酸）and free amino acids.Infants were weighed once each month in thelaboratory , where they also were videotaped consuming a meal of the assigned formula. The meal continued until the infant signaled that s/he was full.Over the seven months of the study, the protein hydrolysate infants gained weight at a slower rate thaninfants fed cow milk formula. Linear growth, or length, did not differ between the two groups, demonstrating that the differences in growth were specifically attributable to weight."All formulas are not alike," said Mennella. "These two formulas have the same amount of calories, but differ considerably in terms of how they influence infant growth."When the data were compared to national norms for breast-fed infants, the rate of weight gain of protein hydrolysate infants was comparable to the breast milk standards; in contrast, infants fed cow's milk formula gained weight at a greater rate than the same breast milk standards.Analysis of the laboratory meal reveals the infants fed the protein hydrolysate formula consumed less formula during the meal."One of the reasons the protein hydrolysate infants had similar growth patterns to breast-fed infants, who are the gold standard, is that they consumed less formula during afeed as compared to infants fed cow's milk formula" said Mennella. "The next question to ask is: Why do infants on cow's milk formula overfed ?"The findings highlight the need to understand the long-term influences of infant formula composition on feeding behavior, growth, and metabolic health. Future studies will utilize measures of energy metabolism and expenditure（支出，花费）to examine how the individual formulas influence growth, and how each differs from breastfeeding.第四章NASA is planning a one-way mission to Mars in a programme called‘Hundred Years Starship’ in which, a manned spacecraft will take astronauts to Mars and leave them there forever.NASA Ames Director Pete Worden revealed that one of NASA’s main research centres, Ames Research Centre, has received 1 million dollars funding to start work on the project.Washington State University researchers had said that while technically feasible, a manned mission to Mars and back is unlikely to lift off anytime soon and so, a manned one-way mission to Mars would not only cut the costs by several fold, but also mark the beginning of long-term human colonization of the planet.Mars is by far the most promising for sustained colonization and development because it is similar in many respects to Earth and, crucially, possesses a moderate surface gravity, an atmosphere, abundant water and carbon dioxide, together with a range of essential minerals.“One approach could be to send four astronauts initially, two on each of two space craft, each with a lander and sufficient supplies, to stake a single outpost on Mars. A one-way human mission to Mars would be the first step in establishing a permanent human presence on the planet,” said Dirk Schulze-Makuch, a Washington State University associate professor.Colleague Paul Davies, a physicist and cosmologist from Arizona State University, added that they aren’t suggesting that astronauts simply be abandoned on the Red Planet for the sake of science; in fact they propose a series of missions over time, sufficient to support long-term colonization. The authors proposed that the astronauts would bere-supplied on a periodic basis from Earth with basic necessities, but otherwise would be expected to become increasingly proficient at harvesting and utilizing resources available on Mars.Eventually they envision that outpost would reachself-sufficiency, and then it could serve as a hub for a greatly expanded colonization programme.First, an appropriate site for the colony would be selected, preferentially associated with a cave or some other natural shelter, as well as other nearby resources, such as water, minerals and nutrients.“Ice caves woul d go a long way to solving the needs of a settlement for water and oxygen. Mars has no ozone shield and no magnetospheric shielding, and ice caves would also provide shelter from ionizing and ultraviolet radiation,” said Schulze-Makuch.The added that in a ddition to offering humanity a “lifeboat” in the event of a mega-catastrophe on Earth, a Mars colony would provide a platform for further scientific research. Schulze-Makuch and Davies acknowledge that such a project would require not only major international cooperation, but a return to the exploration spirit andrisk-taking ethos of the great period of the Earth’s exploration.“Informal surveys conducted after lectures and conference presentations on our proposal have repeatedly shown that many people are willing to volunteer for a one-way mission,both for reasons of scientific curiosity and in a spirit of adventure and human destiny,” they wrote第五章The latest comScore data reveals that during February 2010, 43 million videos were watched on Facebook – which is a 205 percent increase on the year. Last February only 14 million videos were watched via the site.Overall online video viewing in the UK has grown by 37 percent during the last 12 months – with 5.5 billion videos watched via websites during February 2010.Google properties, mainly driven by YouTube, were still the most popular online video destinations, recording1 2.5 billion video views during February 2010, which marked a 17 percent annual increase.The BBC websites ranked second with 140 million videos viewed across its web properties during February 2010, and was followed by Megavideo, which recorded 53 million video views - during the same month.Facebook came fourth in the list, closely followed by Microsoft’s collective web properties. Channel 4 came in sixth position with 39 million videos watched during February 2010 – which was a 76 percent increase on theyear. And ITV came in eighth position recording 29 million video views – which was a 134% increase on the year. Blinkx, the popular video search engine experienced the second largest growth spurt2（急剧增长） , behind Facebook, increasing its video views by 205 per cent over the year. During February 2010, 29 million videos were viewed via the site.Sky came in 10th position, experiencing a 139 percent increase in video views, with 20 million videos watched via its sites during February 2010.The UK video market has grown substantially over the last year, with several aggregators（整合器，聚合器） entering the market, as well as the UK broadcasters increasing their own video presence. Channel 4, for instance, is concentrating on developing its own catch up service, 4oD, whilesigning syndication（辛迪加组织） deals with the likes of YouTube, and new players, likeSeeSaw3.第六章Holding a cell phone against your ear or storing it inyour pocket may be dangerous to your health. This explains a warning that cell phone manufacturers include in the small print that is often ignored when a new phone is purchased. Apple, for example, doesn’t want iPhones to come closer to you than 1.5 centimeters; Research In Motion, BlackBerry’s manufacturer, recommends 2.5 centimeters.If health issues arise from cell phone use, the possible effects are huge. Voice calls—Americans chat on cell phones 2.26 trillion(万亿) minutes annually—earn $109 billion for the wireless carriers.Devra Davis, an expert who has worked for the University of Pittsburgh, has published a book about cell phone radiation, “Disconnect”. The book surveys scientific research and concludes the question is not settled.Brain cancer is a concern that Ms. Davis examines. Over all, there has not been an increase in its incidence since cell phones arrived. But the average marks an increase in braincancer in the 20-to 29 age group and a drop for the older population.“Most cancers have multiple causes,”she says, but she points to laboratory research that suggests low-energy radiation could damage cells that could possibly lead to cancer.Children are more vulnerable to radiation than adults, Ms. Davis and other scientists point out. Radiation that penetrates only five centimeters into the brain of an adult will reach much deeper into the brains of children because their skulls are thinner and their brains contain more absorptive fluid(易吸收的液体). “No studies have yet been completed on cell phone radiation and children,”she says.Henrry Lai, a research professor in the bioengineering department at the University of Washington, began laboratory radiation studies in 1980 and found that rats exposed to radiation had damaged DNA in their brains. Ms. Davis recommends using wired headsets or the phone’s speaker. “Children should text rather than call,”she said,“and pregnant women should keep phones away from the abdomen(腹部). ”第7章The complex fracture pattern created by the earthquake in Concepción (Chile) on 27 February 2010 was to a certain extent predictable（可预言的） . GPS observations from the years before the earthquake showed the pattern of stresses that had accumulated（累积的） through the plate movements during the past 175 years in this area. The stress distribution derived from theobservations correlates（关联） highly with the subsequent fracture distribution. In all likelihood the tremor removed all the stress that had accumulated since the last earthquake in this region, which was observed by Charles Darwin in 1835. An earthquake of similar magnitude in this area is therefore unlikely in the near future. This result was presented by scientists of the GFZ German Centre for Geosciences (Helmholtz Association) in the latest edition of the scientific journal Nature (09 September 2010). "The Maule earthquake near Concepción, Chile, on the 27 Februar registered with a momentum3（势头，动量） magnitude of 8.8, makes it one of the largest earthquakes to have been recorded in its entirety via a modern network ofspace-geodetic and geophysical instruments on the ground," says Professor Onno Oncken, head of theDepartment "Geodynamics" at GFZ. "It thus offers a unique opportunity to compare detailed4observations prior to the earthquake with those taken during and after it, and tore-evaluate hypotheses regarding the predictability of such events."Measurements using the satellite navigation system GPS showed that the seafloor of the Nazca plate in the Pacific Ocean does not slide evenly under the western boundary of the South American continent. Rather, it appears from the GPS measurements that some parts of the ocean floor got locked with the subsurface（地下的） of the continent. In the gaps, however, the Nazca plate continued to push under South America. The resulting uneven5 stress pattern was released by the earthquake of the 27 February in such a way that, just like a zipper6, the locked patcheswere ruptured7（破裂的） one after the other. As a result, this seismic8gap（地震空白区） off the Chilean westcoast is now closed, one last gap remains9 in northern Chile. Here, the GFZ scientists set up a plate boundary observatory10, in order to make use of the entire range of geoscientific instruments to record the conditions before, during andafter an earthquake- an important step in understanding the processes of plate tectonics（地质构造学）.Modern Earth science may still not be able to predict the location, time and magnitude of an earthquake. But the present study offers an optimistic perspective concerning the predictability of possible fracture patterns and magnitudes of expected earthquakes.第八章UC Irvine researchers have discovered that circadian rhythms —the internal body clock —regulate fat metabolism. This helps explain why people burn fat more efficiently at certain times of day and could lead to new pharmaceuticals for obesity, diabetes and energy-related illnesses.The study was headed by Paolo Sassone-Corsi, Donald Bren Professor and chair of pharmacology. A leading expert on circadian rhythms, he discovered many of the key molecular switches governing these biological processes. He and his colleagues found that one of these, a protein called PER2, directly controls PPAR-gamma, a protein essential for lipid metabolism. Since circadian proteins are activated by 24-hour, light-dark patterns, PER2 turns onand off PPAR-gamma’s metabolic capabilities at regular intervals.“What surprised us most, though, is that PER2 targets one specific amino acid on the surface of the PPAR-gamma molecule,”Sassone-Corsi said. “This kind of specificity is very rare in cell biology, which makes it exciting, because it presents us with a singular target for drug development.”Daniele Piomelli, Louise Turner Arnold Chair in Neurosciences at UCI, and Todd Leff, associate professor of pathology at Wayne State University in Detroit, collaborated on the study, which appears this month in Cell Metabolism.Twenty-four-hour circadian rhythms regulate fundamental biological and physiological processes in almost all organisms. They anticipate environmental changes and adapt certain bodily functions to the appropriate time of day. Disruption of these cycles can profoundly influence human health and has been linked to obesity, diabetes, insomnia, depression, heart disease and cancer.Last year, Sassone-Corsi helped discover that proteins involved with circadian rhythms and metabolism areintrinsically linked and dependent upon each other to ensure that cells operate properly and remain healthy. Rajesh H. Amin and James G. Granneman of Wayne State University and UCI’s Benedetto Grimaldi, Marina Maria Bellet, Sayako Katada, Giuseppe Astarita and Jun Hirayama contributed to the current study, supported by the National Institutes of Health.9单元A UFOA UFO is the reported sighting of an object or light seen in the sky or on land,whose appearance,trajectory(轨迹),actions,motions,lights,and colors do not have a logical,conventional,or natural explanation,and which cannot be explained,not only by the original witness,but by scientists or technical experts who try to make a common sense identification after examining the evidence.UFOs (sometimes called flying saucers) became widely discussed only after the first widely publicized U.S.sighting in 1947.Many thousands of such observations have since been reported worldwide.At least 90 percent of UFO sightings can be identified as conventional objects,although time-consuming investigations are often necessary for such identification.The objects most often mistaken for UFOs are bright planets and stars,aircraft,birds,balloons,kites,aerial flares,peculiar clouds,meteors,and satellites.The remaining sightings most likely can be attributed to other mistaken sightings or to inaccurate reporting,hoaxes(恶作剧),or delusions,although to disprove all claims made about UFOsis impossible.From 1947 to 1969 the U.S.Air Force investigated UFOs as a possible threat to national security.A total of 12,618 reports was received,of which 701 reports,or 5.6 percent,were listed as unexplained.The air force concluded that “no UFO reported,investigated,and evaluated by the Air Force has ever given any indication of threat to our national security.” Since 1969 no agency of the ernment has had any active program of UFO investigation.In 1997 the U.S.Central Intelligence Agency (CIA) admitted that the itary had deceived the American public in an effort to hide information about high-altitude spy planes.These planes,the Lockheed U-2A(美国头号军火商洛克西德-马丁公司(Lockheed Martin)生产的侦察机) and the Lockheed SR-71,accounted for over half of the UFO reports during the late 1950s and 1960s.Some persons nevertheless believe that UFOs are extraterrestrial spacecraft,even though no scientifically valid evidence supports that belief.The possibility of extraterrestrial civilizations is not the stumbling block; most scientists grant that intelligent life may well exist elsewherein the universe.A fully convincing UFO photograph of a craftlike object has yet to be taken,however,and the scientific method(科学方法论) requires that highly speculative explanations should not be adopted unless all of the more ordinary explanations can be ruled out.UFO enthusiasts persist,however,and some persons even claim to have been abducted and taken aboard UFOs.No one has produced scientifically acceptable proof of these claims.10单元dreamsScientists think it will be possible to record people's dreams and then interpret them, according to a new report.They claim to have developed a system which allows them to record higher level brain activity.Dr Moran Cerf told the journal Nature: "We would like to read people's dreams."Previously the only way to access people's dreams is for psychologists to ask about them after the event and try to interpret them.Dr Cerf hopes to eventually compare people's memories of their dreams with an electronic visualisation of their brain activity.He told the BBC: "There's no clear answer as to why humans dream. And one of the questions we would like to answer is when do we actually create this dream?"The scientist believes his latest research shows that certain neurons or individual brain cells are linked with specific objects or concepts.He found that a particular neuron lit up when a volunteer thought about Marilyn Monroe.If a database was built up identifying various neurons with concepts, objects and people it would allow them to "read the subject's minds", according to Dr Cerf.However, Dr Roderick Oner, a clinical psychologist and dream expert, said that this kind of visualisation would be of limited help when it came to interpreting the "complex dream narrative".In addition to get a detailed picture of individual neurons su bjects had to have electrodes implanted deep in the brain u sing surgery.The Nature researchers used data from patients who had el ectrodes implanted to monitor and treat them for brain seizu res.However, Dr Cerf said he hoped that it would be possible at a later stage to monitor people without invasive surgery.He said it would be "wonderful" to be able to read the minds of coma patients who are unable to communicate.。