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Official Weibo: http://weibo.com/u/3476904471 大家好，胖胖翔来了！最近气温骤降，各位注意增减衣物~今天的文章中有一篇是关于叙利亚的，内容比较长，大家耐心看~
Part I：Speaker 【Rephrase1】 Article 1 Seeing Photos of Food Makes Actual Food Less Tasty Transcript hided [Dialog, 1:27]
Pictures of food. Snapping photos of meals is one of the less expected viral social media trends. That megaburger, the cheesy burrito, the strawberry shortcake, captured forever as an object of desire. But food photography can backfire. Because a recent study finds that looking at a lot of photos of food can make foods similar to those pictured less enjoyable to eat. Due to what scientists call “sensory boredom.” Researchers had more than 230 people look at and rate photos of food. Half of the group viewed and rated 60 pics of sweets like cake and chocolates. The other half saw and rated 60 photos of savory foods like chips and pretzels. Then everyone in the study ate salted peanuts and rated them. And the subjects who had seen photos of salty foods enjoyed the salted peanuts less than did the participants who had seen pictures of sweets. The study is the Journal of Consumer Psychology. The salty group never actually saw any peanut photos. But, the researchers say, viewing the salty food photos had satiated their sensory experience of saltiness—making yet more of the same less appealing. Seems that a picture may be worth a thousand tastes. —Christie Nicholson
Source: http://www.scientificamerican.com/podcast/episode.cfm?id=seeing-photos-of-food-makes-actual-13-10-09
Part II：Speed 【Time 2】 Article 2 The First-Known Comet to Strike Earth
A black, diamond-spackled pebble just a few centimeters across is the remainder of a comet that struck Earth almost 29 million years ago—making it the first direct evidence of a comet exploding in our atmosphere, scientists say. The stone, which the scientists named “Hypatia” after an Alexandrine mathematician and philosopher, was found in 1996 among tumbled bits of yellow sand glass (also known as the Libyan Desert Glass) scattered across tens of kilometers in southwestern Egypt, near the border with Libya. The glass itself, one large polished piece of which has a prominent place in a necklace that belonged to Egyptian pharaoh Tutankhamen, has been dated to 28.5 million years and has long been thought to be the result of a meteorite impact or an airburst caused by a comet breaking up in Earth’s atmosphere. To determine its origin, scientists performed a range of tests on the tiny pebble, examining its mineralogy, bulk chemistry, carbon isotope, and noble gas content. The stone’s noble gas content supports an extraterrestrial origin, while the presence of tiny diamonds—larger than nanodiamonds found in a common kind of meteorite called chondrites, but similar in size to diamond aggregates known to be formed by impacts—supports a cometary origin. The stone is also markedly carbon-rich, more so than other known extraterrestrial material aside from comets, the researchers will report in an upcoming issue of Earth and Planetary Science Letters. All of this, they say, points to a cometlike object entering Earth’s atmosphere, where it exploded, cooking the desert sand below to 2000°C and forming the Libyan Desert Glass.
字数[264] Source: http://news.sciencemag.org/earth/2013/10/scienceshot-first-known-comet-strike-earth?rss=1
【Time 3】
Article 3
We must preserve Syria’s scientific assets Scientist Amal Alachkar talks to Nature about the effects of the civil war on researchers in her home country.
The exodus of scientists out of Syria as a result of war was the topic of crisis talks organized by the Institute of International Education (IEE) in New York last week. In the past two years, 98 Syrian scholars have applied to the IEE's Scholar Rescue Fund (SRF), which provides fellowships abroad to faculty who are threatened in their home countries. About ten times more than applied between 2002 and 2011.
Syrian neuropharmacologist Amal Alachkar, an SRF fellow at the University of California, Irvine, was at the meeting. An expert on the neurological causes of schizophrenia and depression, Alachkar founded the first neuroscience research lab in Syria, which opened at the University of Aleppo in 2010. But she fled the country in 2011, out of fear of retaliation for her critical position towards the government. She talked to Nature about her experiences.
What was the academic world like in Syria before the war? After 40 years of dictatorship, you see no culture of free speech, and corruption: positions in the administration largely depend on loyalty to the regime. On the other hand, in the last few years we have witnessed a slow improvement, thanks to young scholars educated abroad.
What role did professors have in the Syrian uprising? Students ignited the uprising, but professors did not take a prominent role: they had bad experiences in the 1980s, when several opposition faculty disappeared.
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【Time 4】
What position did you take? After the massacre of Deraa in March 2011, I condemned it during my lectures. Just two days later, I was interrogated by the [Syrian] Air Force. I was released, but the warning was clear: never do it again, because next time it won't be like this. Only three months after, philosophy professor Jamal Tahhan was arrested for his peaceful protests and tortured. Many other detentions, tortures and killings of scholars followed.
Why did you leave Syria? I felt my life would be in danger if I continued to speak out. So I left in August 2011, thanks to a Hubert H. Humphrey Fellowship at Pennsylvania State University [in University Park]. I thought this ugly regime would fall in less than 10 months, as in Libya, Egypt or Tunisia. But it was not so. So I have remained in the United States with an SRF fellowship since June 2012.
Why are scholars targeted? Sometimes for their political opinions: that’s why hundreds of professors don’t speak out. Sometimes they are killed by random shelling or snipers or at checkpoints. Sometimes, for coming from certain cities or having certain surnames. Some medical doctors are targeted for helping people in the areas under attack. The regime is afraid of professors. When I posted a picture on Facebook of myself demonstrating in the United States on the anniversary of the uprising, a student commented: “Your lectures in pharmacology were great, but this is one of your greatest lectures.”
Does violence against scientists come from the government only, or also from rebels? I have heard that some scholars have been targeted [by the rebels] for belonging to a minority, but the number is much smaller [than that of] those targeted by the regime.
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【Time 5】
How is research infrastructure affected by the war? My lab was targeted by Shabiha, [a militia that supports Bashar al-Assad, the president of Syria]. They broke in and destroyed it while trying to catch students. The five main public universities, all under the government’s control, are still working somehow. But the education system has collapsed. My department has lost its entire staff — some fled the country, and others are not able to get to the university.
What is the effect of these refugee movements? This is the most tragic problem. Many students leave the country without documents, so they cannot study abroad. Moreover, tuition fees are very high in Jordan. Egypt has revoked the law that made Syrian [university] students’ fees the same as Egyptian students' fees. Fortunately, Turkey has put in place a similar law.
What is faculty life like in Syria? The regime has stopped the collaborations my group had with [researchers in] Turkey, the United States and Europe, because they are considered enemies. Sanctions and an increased budget for the military generate a large lack of material and financial resources for research. We had a very good cell line in the University of Aleppo, but it was lost after an electricity cut of several days.
What can be done to help? If each university abroad could support just one [scholar], thousands of minds would be saved. The IIE is also working on a distance-learning programme for students in refugee camps. The Free Syrian University on the Turkish border has started enrolling students.
What happens if we do not support scientists in Syria? The regime will fall sooner or later, but the country will have to be rebuilt. We are facing a lost generation, hundreds of thousands of students lacking access to education. A new higher-education system is essential to bring back the culture of freedom, democracy, tolerance and reconciliation in Syria: without all this we are going to face a fragmented country. There is no chance to move our country forward without intellectual power.
字数[337] http://www.nature.com/news/we-must-preserve-syria-s-scientific-assets-1.13940
【Time 6】 Article 4 Blood-filled mosquito is a fossil first Insect’s bloated abdomen carries traces of blood molecules that are 46-million-years old.
Jurassic Park’s iconic image of a fossilized blood-filled mosquito was thought to be fiction — until now. For the first time, researchers have identified a fossil of a female mosquito with traces of blood in its engorged abdomen. A team led by Dale Greenwalt at the US National Museum of Natural History in Washington DC reports the fossil discovery today in Proceedings of the National Academy of Sciences.
Although scientists have found fossils of suspected blood-sucking insects, the creatures' feeding habits have mostly been inferred from their anatomy or the presence of blood-borne parasites in their guts. But Greenwalt's fossilized mosquito contains molecules that provide strong evidence of blood-feeding among ancient insects back to 46 million years ago. It is a fortunate find. “The abdomen of a blood-engorged mosquito is like a balloon ready to burst. It is very fragile,” says Greenwalt. “The chances that it wouldn’t have disintegrated prior to fossilization were infinitesimally small.”
A long shot The insect was found not in amber, as depicted in Jurassic Park, but in shale sediments from Montana. After 46 million years, any DNA would be long degraded, but other molecules can survive. Greenwalt’s team showed that the insect’s abdomen still contains large traces of iron and the organic molecule porphyrin — both constituents of haemoglobin, the oxygen-carrying pigment found in vertebrate blood. These molecules were either rare or absent in the abdomen of a fossilized male mosquito (which does not drink blood) of the same age, found at the same location.
“This shows that details of a blood-sucking mosquito can be nicely preserved in a medium other than amber,” says George Poinar, who studies fossilized insects at Oregon State University in Corvallis. “It also shows that some porphyrin compounds in vertebrate blood can survive under the right conditions for millions of years.” Greenwalt suggests that this provides support for the controversial claims of Mary Schweitzer, a palaeontologist at North Carolina State University in Raleigh, who has reportedly isolated haemoglobin traces from dinosaur bones.
字数[331] Source: http://www.nature.com/news/blood-filled-mosquito-is-a-fossil-first-1.13946
Part III： Obstacle
【Paraphase7】
Article 5
How Exercise Beefs Up the Brain Mind over matter. New research explains how abstract benefits of exercise—from reversing depression to fighting cognitive decline—might arise from a group of key molecules.
While our muscles pump iron, our cells pump out something else: molecules that help maintain a healthy brain. But scientists have struggled to account for the well-known mental benefits of exercise, from counteracting depression and aging to fighting Alzheimer’s and Parkinson’s disease. Now, a research team may have finally found a molecular link between a workout and a healthy brain.
Much exercise research focuses on the parts of our body that do the heavy lifting. Muscle cells ramp up production of a protein called FNDC5 during a workout. A fragment of this protein, known as irisin, gets lopped off and released into the bloodstream, where it drives the formation of brown fat cells, thought to protect against diseases such as diabetes and obesity. (White fat cells are traditionally the villains.)
While studying the effects of FNDC5 in muscles, cellular biologist Bruce Spiegelman of Harvard Medical School in Boston happened upon some startling results: Mice that did not produce a so-called co-activator of FNDC5 production, known as PGC-1α, were hyperactive and had tiny holes in certain parts of their brains. Other studies showed that FNDC5 and PGC-1α are present in the brain, not just the muscles, and that both might play a role in the development of neurons.
Spiegelman and his colleagues suspected that FNDC5 (and the irisin created from it) was responsible for exercise-induced benefits to the brain—in particular, increased levels of a crucial protein called brain-derived neurotrophic factor (BDNF), which is essential for maintaining healthy neurons and creating new ones. These functions are crucial to staving off neurological diseases, including Alzheimer’s and Parkinson’s. And the link between exercise and BDNF is widely accepted. “The phenomenon has been established over the course of, easily, the last decade,” says neuroscientist Barbara Hempstead of Weill Cornell Medical College in New York City, who was not involved in the new work. “It’s just, we didn’t understand the mechanism.” To sort out that mechanism, Spiegelman and his colleagues performed a series of experiments in living mice and cultured mouse brain cells. First, they put mice on a 30-day endurance training regimen. They didn’t have to coerce their subjects, because running is part of a mouse’s natural foraging behavior. “It’s harder to get them to lift weights,” Spiegelman notes. The mice with access to a running wheel ran the equivalent of a 5K every night.
Aside from physical differences between wheel-trained mice and sedentary ones—“they just look a little bit more like a couch potato,” says co-author Christiane Wrann, also of Harvard Medical School, of the latter’s plumper figures—the groups also showed neurological differences. The runners had more FNDC5 in their hippocampus, an area of the brain responsible for learning and memory.
Using mouse brain cells developing in a dish, the group next showed that increasing the levels of the co-activator PGC-1α boosts FNDC5 production, which in turn drives BDNF genes to produce more of the vital neuron-forming BDNF protein. They report these results online today in Cell Metabolism. Spiegelman says it was surprising to find that the molecular process in neurons mirrors what happens in muscles as we exercise. “What was weird is the same pathway is induced in the brain,” he says, “and as you know, with exercise, the brain does not move.” So how is the brain getting the signal to make BDNF? Some have theorized that neural activity during exercise (as we coordinate our body movements, for example) accounts for changes in the brain. But it’s also possible that factors outside the brain, like those proteins secreted from muscle cells, are the driving force. To test whether irisin created elsewhere in the body can still drive BDNF production in the brain, the group injected a virus into the mouse’s bloodstream that causes the liver to produce and secrete elevated levels of irisin. They saw the same effect as in exercise: increased BDNF levels in the hippocampus. This suggests that irisin could be capable of passing the blood-brain barrier, or that it regulates some other (unknown) molecule that crosses into the brain, Spiegelman says.
Hempstead calls the findings “very exciting,” and believes this research finally begins to explain how exercise relates to BDNF and other so-called neurotrophins that keep the brain healthy. “I think it answers the question that most of us have posed in our own heads for many years.”
The effect of liver-produced irisin on the brain is a “pretty cool and somewhat surprising finding,” says Pontus Boström, a diabetes researcher at the Karolinska Institute in Sweden. But Boström, who was among the first scientists to identify irisin in muscle tissue, says the work doesn’t answer a fundamental question: How much of exercise’s BDNF-promoting effects come from irisin reaching the brain from muscle cells via the bloodstream, and how much are from irisin created in the brain?
Though the authors point out that other important regulator proteins likely play a role in driving BDNF and other brain-nourishing factors, they are focusing on the benefits of irisin and hope to develop an injectable form of FNDC5 as a potential treatment for neurological diseases and to improve brain health with aging.
字数[852] Source: http://news.sciencemag.org/biology/2013/10/how-exercise-beefs-brain
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