科学美国人60秒 SSS High-Sugar Diet Makes Flies Drop Like...Flies
时间：2018-12-24 作者：英语课 分类：2017年Scientific American(一)月
I don’t believe, in all my years, I have ever seen a fruit fly I would consider obese 1. But, thanks to the wonders of modern science, that’s all about to change. Because a team of researchers from Cold Spring Harbor laboratory has produced the first flies that are genetically 3 engineered to overeat.
If you are wondering…why…it’s not as silly as it might sound. A big part of weight control has to do with making healthy dietary choices and knowing when to step away from the snack cabinet. But what controls those behaviors?
Well, we humans have a hormone 4 called leptin that tells us that we’re full. After eating, leptin is released from our fat cells. And it travels to our brains to signal that we’ve had enough. Indeed, people who don’t produce leptin…or who lack the molecular 5 machinery 6 to detect it…really pack on the pounds.
In the new study, researchers discovered a hormone that acts the same way in flies. And when they deleted the gene 2 that encodes it, the hormonally deficient 7 insects just kept eating. And when presented with the fly equivalent of a high-fat or high-sugar diet, they gained three times more weight than did their hormonally competent peers. The findings appear in the journal Cell Metabolism 8. [Jennifer Beshel et al., A Leptin Analog 9 Locally Produced in the Brain Acts via a Conserved 10 Neural 11 Circuit to Modulate 12 Obesity-Linked Behaviors in Drosophila]
Interestingly, giving human leptin to these tubby bugs 13 eliminates their tendency to binge. That suggests that by studying these flies, scientists might learn something that’s relevant to us.
In the meantime, researchers from the U.K. and Australia have also been plying 14 flies with sweet treats. And they found that consuming large amounts of sugar may lead to fewer birthday cakes.
In this study, researchers compared the life spans of flies that ate a healthy diet, with 5 percent sugar…to those that went on a three-week bender of 40 percent sucrose. That’s the equivalent, the researchers note, of a person who really took Marie Antoinette’s advice to heart and ate only cake for two decades.
The results? The sugar-fed flies lost about 7 percent of their already brief 90-day life span. And that was even if they reverted 15 to the healthy diet after their three weeks on sweets. These results appear in the journal Cell Reports. [Adam J. Dobson et al, Nutritional 16 Programming of Lifespan by FOXO Inhibition on Sugar-Rich Diets]
The sugar overload 17 apparently 18 triggered long-term changes in gene activity…which accelerated aging and had the sugar-buzzed flies dropping like, well, like flies.
The findings suggest that you can have your cake and eat it, too. But not for long.
—Karen Hopkin
[The above text is a transcript 19 of this podcast.]
- The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
- Being obese and lazy is dangerous to health.又胖又懒危害健康。
- A single gene may have many effects.单一基因可能具有很多种效应。
- The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
- All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
- Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物
- Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
- This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
- The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
- For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
- Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗？
- Machinery ought to be well maintained all the time.机器应该随时注意维护。
- The crops are suffering from deficient rain.庄稼因雨量不足而遭受损害。
- I always have been deficient in selfconfidence and decision.我向来缺乏自信和果断。
- After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
- All living matter undergoes a process of metabolism.生物都有新陈代谢。
- The analog signal contains high-frequency video information,which helps make up the picture.模拟信号包括有助于构成图像的高频视频信息。
- The analog computer measures continuously,without proceeding step by step.模拟计算机不是一步一步地进行，而是连续地进行量度。
- He conserved his energy for the game. 他为比赛而养精蓄锐。 来自《简明英汉词典》
- Under these conditions, the total mechanical energy remains constant, or is conserved. 在这种条件下，总机械能保持不变或机械能保存。 来自辞典例句
- The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
- The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。
- Please modulate the sound on the TV.请调节一下电视的音量。
- This system could modulate the voice signal effectively.这个系统可以对语音信号进行有效的调制。
- All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
- The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》
- All manner of hawkers and street sellers were plying their trade. 形形色色的沿街小贩都在做着自己的买卖。 来自《简明英汉词典》
- It was rather Mrs. Wang who led the conversation, plying Miss Liu with questions. 倒是汪太太谈锋甚健，向刘小姐问长问短。 来自汉英文学 - 围城
- After the settlers left, the area reverted to desert. 早期移民离开之后，这个地区又变成了一片沙漠。
- After his death the house reverted to its original owner. 他死后房子归还给了原先的主人。
- A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
- The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。
- Don't overload the boat or it will sink.别超载，否则船会沉。
- Large meals overload the digestive system.吃得太饱会加重消化系统的负担。
- An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
- He was apparently much surprised at the news.他对那个消息显然感到十分惊异。
- A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
- They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。