The True Bottom of the Food Chain is Plenty Polluted

中文批注

这篇文章的难度稍微有点大，一是因为要求的词汇量相对较高，二是因为文章的内容不那么容易理解。所以如果在第一遍听的时候无法完全理解，或者说无法理解大部分，大家也用不担心。可以借助Full transcript再听一遍，看自己是否能加深些理解。如果仍是因为有不少生词而无法理解文章大致的意思，那么就可以参考下文的key vocabulary来进行进一步的理解。

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[Key vocabulary]

Venture: Vt. 敢于，Vi. 冒险，投机

Trench: n. 沟渠，Vt. 掘沟

Submersible: adj. 能潜水的

Voyage: n. 航程，航行；Vi. 航行，航海

Critter: n. 人，家禽，马，牛

Compound: n. [化学], 化合物，混合物；adj. 复合的，混合的；V. 合成，混合

Polychlorinated: 多氯化的

Biphenyl: [有化] 联苯，联二苯

Retardant: n. [化学] 阻滞剂，抑制剂

Nanogram: n. 纳克， [计量] 毫微克

Pollutant: n. 污染物

Robotic: adj. 机器人的，自动的，机械的

Trap: n. 陷阱，圈套

Amphipod: 片脚类动物

Scavenger: n. 食腐动物，清除剂

Carcasses: n. 尸体，兽体

Coastline: n. 海岸线

Swirling: n. 漩涡，涡流；V. 打旋，眩晕

Gobble: Vt. 狼吞虎咽；Vi. 贪食

Reproduce: Vt. 复制，再生，生殖

Faring: V. 进展，进步，经营 (Fare的ing形式)

Exempt: Vt. 免除，豁免；Adj. 被免除的，被豁免的

Full Transcript

Critters living more than six miles below the ocean surface contain high levels of harmful compounds like PCBs and flame retardants. Julia Rosen reports.

The Mariana Trench is the deepest spot in the world’s oceans. Only three humans have ventured into the trench in submersibles. But plenty of our pollution has made the voyage to the bottom of the sea: a new study finds that critters living more than six miles below the ocean surface contain high levels of harmful compounds like polychlorinated biphenyls, or PCBs, and flame retardants.

“An important thing is that, if you’re in the deepest place in world, there’s no place to go.”

Alan Jamieson, a marine ecologist at Newcastle University in the U.K.

“You can’t be disturbed horizontally. You can’t go back up. So, for every nanogram of pollutant that’s gone into the deep sea, there’s no mechanism to put it back again. So, of course the values are going to be high, cause it’s only a one way traffic, right?”

Jamieson and his colleagues used robotic traps to collect deep-sea amphipods living in the most remote parts of the oceans. These creatures look a bit like shrimp, and they’re well adapted to their extreme environment, he says.

“The deep sea-ones are incredible scavengers. This is why they thrive in the deep sea, because it’s a low-food environment where most of their food comes from dead carcasses raining from the surface or particulates coming down. So, everything from an organic particle to a dead whale is fair game to an amphipod.”

The food that floats down to the ocean bottom carries man-made contaminants, including PCBs, which entered the surface ocean from rivers and coastlines. Companies stopped manufacturing these chemicals in the 1970s, after they were found to be dangerous. But they don’t break down easily, so they’re still swirling around in the oceans and working their way down to the seafloor, where amphipods gobble them up.

The research was published in the journal Nature Ecology and Evolution. [Alan J. Jamieson et al., Bioaccumulation of persistent organic pollutants in the deepest ocean fauna]

In many surface-dwelling species, PCBs have been shown to interfere with animals’ abilities to reproduce. Jamieson says they don’t have enough data yet to know how deep-sea amphipods are faring, because they’re much harder to study. But he says that wasn’t his motivation for studying pollutants in the deep ocean.

“The point is that they are there. It’s to challenge people’s perception that the deep sea is not exempt from what’s happening in the rest of the world. And that’s a perception we hear quite a lot of.”

— Julia Rosen

(Source: https://www.scientificamerican.com/podcast/episode/the-true-bottom-of-the-food-chain-is-plenty-polluted/)

Blood Cells Remember Your Mountain Vacation

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这篇文章的内容是关于爬山和红细胞蛋白之间的联系。爬的越高，可能让你放慢脚步的不一定是陡峭的山路，可能会是因为越发稀薄的空气氧气。研究表示，想要习惯爬山，并没有捷径，只有经常练习，身体方面也会有所记忆，记住该如何适应，如何“beat”~

这篇文章的内容从理解方面来说，并不是特别难。如果大家的目标分数是65或者79，那么在第一遍做听力练习的时候，就应该能听明白七七八八，之后再对照着Full Transcript来练习的时候，就不应该再有过多的问题了哦~ 对于目标79分的同学来说这篇文章很适合拿来做summarize的练习。

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【Key Vocabulary】

Steep: adj. 陡峭的，急剧升降的

Strenuous: adj. 紧张的，费力的

Biochemical: adj. 生物化学的

Acclimate: Vt. 使适应，适应新环境

Deplete: Vt. 耗尽，用尽，使衰竭

Accumulate: Vt. 积攒

Erythrocyte: 红细胞，红血球

Retain: V. 保留，保有

Hypoxic: [病理学] 氧过少的，低氧的

Adenosine: n. 腺苷，腺苷酸

Caveat: n. 警告，告诫

Shortcut: n.捷径，快捷方式

Acclimatization: n. 适应环境，气候适应

Full Transcript

Red blood cells retain a memory of high-altitude exposure, allowing for faster acclimation next time. But that memory fades within four months. Christopher Intagliata reports. 

Head to the mountains, and if the steep trails don’t slow you down, the thin air will. There’s less oxygen up there—so strenuous activity can leave you dizzy, out of breath…or worse. But even though you’re beat, biochemical processes are already busy at work, acclimating your body.

Scientists investigated those pathways in humans and mice. They found that exposure to low oxygen depletes stores of a red-blood-cell protein called eENT1. That’s a good thing. Because now other substances that protect your body against low oxygen are free to rapidly accumulate and help the body adapt.

But here’s the kicker—once the eENT1 protein goes away, it doesn’t come back. Meaning red blood cells kind of ‘remember’ their altitude exposure. And that means if you hit the mountains again soon enough, you can acclimate faster than you did the first time. The findings are in the journal Nature Communications. [Anren Song et al., Erythrocytes retain hypoxic adenosine response for faster acclimatization upon re-ascent]

There is one caveat. “In humans the red blood cell lifespan is 120 days.” Study author Yang Xia, a biochemist with the UT Health Science Center in Houston. “So the longer you stay at sea level before you re-climb to high altitude, then such memory will gradually disappear.” So unless you’re a frequent mountain climber—there’s really no shortcut to acclimatization. Then again, there’s no shortcut to the summit, either.

—Christopher Intagliata

(Source: https://www.scientificamerican.com/podcast/episode/blood-cells-remember-your-mountain-vacation/)