The Search for the Anti-·aging Pill单词分析

READING PASSAGE 3

You should spend about 20 minutes on Questions 28—40, which are based on Reading Passage 3

The Search for the Anti-·aging Pill

In government laboratories and elsewhere, scientists are seeking a drug able to prolong life and youthful

vigor．Studies of caloric restriction are showing the way.

As researchers on aging noted recently, no treatment on the market today has been proved to slow human aging—the build-up of molecular1and cellular2damage that increases vulnerability3to infirmity as we grow older．But one intervention4，consumption5 of a low-calorie*yet nutritionally 6balanced diet．works incredibly well in a broad range of animals，increasing longevity7and prolonging good health．Those findings suggest that caloric restriction8could delay aging and increase longevity in humans, too．

Unfortunately, for maximum benefit，people would probably have to reduce their caloric intake by roughly thirty per cent，equivalent9 to dropping from 2,500 calories a day to l,750．Few mortals10 could stick to that harsh a regimen11，especially for years on end．But what if someone could create a pill that mimicked12the physiological effects of eating less without actually forcing people to eat less? Could such a‘ caloric-restriction mimetic13’，as we call it，enable people to stay healthy longer, postponing14 age-related disorders(such as diabetes15，arteriosclerosis16，heart disease and cancer)until very late in life? Scientists first posed this question in the mid-1 990s．after researchers came upon a chemical agent that in rodents17

１adj. [化学] 分子的；由分子组成的 2 n. 移动电话；单元adj. 细胞的；多孔的；由细胞组成的 3 n. 易损性；弱点 4 n. 介入；调停；妨碍 5 n. 消费；消耗；肺痨 6 adv. 滋养地 7 n. 长寿，长命；寿命 8 n. 限制；约束；束缚 9 n. 等价物，相等物 adj. 等价的，相等的；同意义的 10adj. 凡人的；致死的；终有一死的；不共戴天的n. 人类，凡人 11 n. [医] 养生法；生活规则；政体；支配 12 v. 模仿（活象） 13 adj. 模仿的；拟态的；类似的 14 n. 推迟 15 n. 糖尿病；多尿症 16动脉硬化 17 n. 啮齿动物seemed to reproduce many of caloric restriction's benefits．No compound that would

safely achieve the same feat in people has been found yet，but the search has been informative１and has fanned hope that caloric-restriction (CR) mimetics can indeed be developed eventually．

The benefits of caloric restriction

The hunt for CR mimetics grew out of a desire to better understand caloric restriction's many effects on the body．Scientists first recognized the value of the practice more than 60 years ago，when they found that rats fed a low-calorie diet lived longer on average than free-feeding rats and also had a reduced incidence2of conditions that become increasingly common in old age．What is more，some of the treated animals survived longer than the oldest—living animals in the control group，which means that the maximum lifespan3(the oldest attainable4 age)，not merely the normal lifespan，increased．Various interventions，such as infection-fighting5drugs，can Increase a population's average survival time，but only approaches that slow the body's rate of aging will increase the maximum lifespan．

The rat findings have been replicated6 many times and extended to creatures7 ranging from yeast to fruit flies，worms，fish，spiders，mice and hamsters8．Until fairly recently, the studies were limited to short-lived9creatures genetically10distant from humans．But caloric．restriction projects underway in two species more closely related to humans-rhesus and squirrel monkeys-have made scientists optimistic that CR mimetics could help people．

1adj. 教育性的，有益的；情报的；见闻广博的 2 n. 发生率；影响；[光] 入射；影响范围 3 n. 寿命；预期生命期限；预期使用期限 4 adj. 可得到的；可达到的；可到达的 5避免传染 6重复的 7 n. 生物 8 n. 仓鼠 9 adj. 短暂的，短期的；短命的；无常的

10 adv. 从遗传学角度；从基因方面

The monkey projects demonstrate1 that, compared with control animals that eat

normally, caloric-restricted monkeys have lower body temperatures and levels of the pancreatic hormone insulin2，and they retain more youthful levels of certain hormones that tend to fall with age．

The caloric-restricted animals also look better on indicators of risk for age-related diseases．For example，they have lower blood pressure and triglyceride3 levels(signifying4 a decreased likelihood5of heart disease)，and they have more normal blood glucose6levels(pointing to a reduced risk for diabetes，which is marked by unusually high blood glucose levels)．Further, it has recently been shown that rhesus monkeys kept on caloric—restricted diets for an extended time(nearly 15 years)have less chronic7disease．They and the other monkeys must be followed still longer, however, to know whether low-calorie intake8can increase both average and maximum lifespans in monkeys．Unlike the multitude9 of elixirs10 being touted11as the latest anti-aging cure，CR mimetics would alter fundamental12processes that underlie13 aging．We aim to develop compounds that fool cells into activating maintenance14 and repair．

1 vt. 证明；展示；论证 vi. 示威 2胰腺胰岛素 3 n. 甘油三酸酯 4 n. 代表；预示 v. 象徵；预示 5 n. 可能性，可能

6血糖 7 adj. 慢性的；长期的；习惯性的 8 n. 摄取量；通风口；引入口；引入的量 9 n. 群众；多数 10 n. 不老长寿药；万能药；炼金药 11 v. 招来顾客adj. 被吹捧的 12基本 13 vt. 成为……的基础；位于……之下 14 n. 维护，维修；保持；生活费用

How a prototype caloric—restriction mimetic works

The best-studied candidate1for a caloric-restriction mimetic，2DG (2-deoxy-D-glucose)，works by interfering with the way cells process glucose．It has proved toxic2 at some doses in animals and so cannot be used in humans．But it has demonstrated3 that chemicals can replicate4the effects of caloric restriction；the trick is finding the right one．

Cells use the glucose from food to generate ATP (adenosine triphosphate5)，the molecule that powers many activities in the body．By limiting food intake，caloric restriction minimizes the amount of glucose entering cells and decreases ATP generation．When 2DG is administered to animals that eat normally，glucose reaches cells in abundance6but the drug prevents most of it from being processed and thus reduces ATP synthesis．Researchers have proposed several explanations7for why interruption8of glucose processing and ATP production might retard aging．One possibility relates to the ATP-making machinery9’s emission of free radicals10,which are thought to contribute to aging and to such age-related diseases as cancer by damaging cells．Reduced operation of the machinery should limit their production and thereby constrain the damage．Another hypothesis11 suggests that decreased processing of glucose could indicate to cells that food is scarce(even if it isn’t)and induce12 them to shift into an anti-aging mode that emphasizes preservation13 of the organism14 over such‘luxuries15’as growth and reproduction．

1 n. 候选人，候补者；应试者

2 adj. 有毒的；中毒的

3 vt. 证明；展示；论证 vi. 示威

4 n. 复制品；八音阶间隔的反覆音

vt. 复制；折叠 adj. 复制的；折叠的 5三磷酸腺苷 6大量的；丰富的；充足的 7解释 8 n. 中断；干扰；中断之事 9 n. 机械；机器；机构；机械装置 10 n. 自由基；激进分子；根基 11 n. 假设 12 vt. 诱导；引起；引诱；感应 13 n. 保存，保留 14 n. 有机体；生物体；微生物 15 n. 奢侈品

Ant Intelligence

When we think of intelligent members the animal kingdom, the creatures that spring immediately to mind are apes and monkeys. But in fact the social lives of some members of the insect kingdom are sufficiently1complex to suggest more than a hint2 of intelligence. Among these, the world of the ant has come in for considerable3 scrutiny4lately, and the idea that ants demonstrate sparks of cognition6 has certainly not been rejected by those involved in these investigations.

Ants store food．repel 7attackers and use chemical signals to contact one another in case of attack．Such chemical communication can be compared to the human use of visual and auditory channels8(as in religious chants9，advertising images and jingles10，political slogans and martial11music)to arouse and propagate12moods and attitudes．The biologist Lewis Thomas wrote，Ants are so much like human beings as to be an embarrassment13．They farm fungi14, raise aphids15*as livestock16, launch armies to war, use chemical sprays to alarm and confuse enemies，capture slaves，engage in child labour, exchange information ceaselessly17．They do everything but watch television．’

However, in ants there is no cultural transmission-everything must be encoded in the genes19whereas in humans the opposite is true. Only basic instincts are carried in the genes of a newborn baby, other skills being learned from others in the community as the child grows up. It may seem that this cultural continuity gives us a huge advantage

1 adv. 充分地；足够地

2 n. 暗示；线索vt. 暗示；示意vi. 示意

3 adj. 相当大的；重要的，值得考虑的

4 n. 详细审查；监视；细看；选票复查 6 n. 认识；知识；认识能力 7 vt. 击退；抵制；使厌恶；使不愉快 8听觉通道 9宗教圣歌 10 n. 叮当声vt. 使押韵；使发出叮当声 vi. 发出叮当声；押韵 11 adj. 军事的；战争的；尚武的 12 vt. 传播；传送；繁殖；宣传 13 n. 窘迫，难堪；使人为难的人或事物；拮据 14 n. 真菌；菌类；蘑菇 1

5 n. 蚜虫类 1

6 n. 牲畜；家畜 1

7 adv. 不停地

over ants. They have never mastered fire nor progressed. Their fungus farming and

aphid herding crafts1are sophisticated2 when compared to the agricultural skills of humans five thousand years ago but have been totally overtaken by modern human agribusiness.3

Or have they? The farming methods of ants are at least sustainable4．They do not ruin environments or use enormous5amounts of energy．Moreover, recent evidence suggests that the crop farming of ants may be more sophisticated and adaptable than was thought. Ants were farmers fifty million years before humans were．Ants can’t digest the cellulose 6in leaves-but some fungi can．The ants therefore cultivate7these fungi in their nests，bringing them leaves to feed on, and then use them as a source of food．Farmer ants secrete antibiotics8to control other fungi that might act as‘weeds’，and spread waste to fertilise9 the crop.

It was once thought that the fungus that ants cultivate was a single type that they had propagated10．Essentially unchanged from the distant past．Not so. Ulrich Mueller of Maryland and his colleagues genetically screened 11862 different types of fungi taken from ants’nests. These turned out to be highly perse：it seems that ants are continually domesticating12 new species．Even more impressively, DNA analysis of the fungi suggests that the ants improve or modify the fungi by regularly swapping13 and sharing strains with neighbouring14ant colonies. Whereas prehistoric18 man had no exposure19 to Urban lifestyles-the forcing house of intelligence—the evidence suggests that ants have lived in urban settings for close on a hundred million years，

1放牧工艺品 2 adj. 复杂的；精致的；久经世故的；富有经验的 v. 使变得世故；使迷惑；篡改 3 n. 农业综合企业（包括农业设备、用品的制造、农产品的产销、制造加工等 4可持续 5 adj. 庞大的，巨大的；凶暴的，极恶的 6 n. 纤维素；（植物的）细胞膜质

7 vt. 培养；陶冶；耕作 8 n. 抗生素；抗生学 9 vt. 使受精；施肥于；使肥沃 10 vt. 传播；传送；繁殖；宣传vi. 繁殖；增殖

14 adj. 邻近的；附近的；接壤的

developing and maintaining underground cities of specialized chambers and tunnels.

When we survey Mexico City, Tokyo，Los Angeles．we are amazed at what has been accomplished by humans．Yet Hoelldobler and Wilson’s magnificent1 work for ant lovers, The Ants, describes a super colony of the ant Formica yessensis on the Ishikari Coast of Hokkaido．This‘megalopolis2’was reported to be composed of 360 million workers and a million queens living in 4,500 Interconnected3 nests across a territory4of 2.7 square kilometres．

Such enduring and intricately meshed6 levels of technical achievement outstrip5 by far anything achieved by our distant ancestors. We hail as masterpieces6the cave Paintings in southern France and elsewhere，dating back some 20，000 years. Ant societies existed in something like their present form more than seventy million years ago．Beside this, prehistoric man looks technologically primitive. Is this then some kind of intelligence，albeit7 of a different kind?

Research conducted at Oxford，Sussex and Zurich Universities has shown that when desert ants return from a foraging trip, they navigate by integrating bearings8 and distances，which they continuously update9 in their heads．They combine the evidence of visual landmarks10with a mental library of local directions, all within a framework11Which is consulted and updated.So ants can learn too．

And in a twelve-year Programme of work，Ryabko and Reznikova have found evidence that ants can transmit very complex messages.Scouts who had located food

1 adj. 高尚的；壮丽的；华丽的；宏伟的 2n. 特大都市；人口稠密地带 3 adj. 连通的；有联系的 v. 互相连接 4n. 领土，领域；范围；地域；版图 5vt. 超过；胜过；比…跑得快 6 n. 杰作；绝无仅有的人 7 conj. 虽然；即使 8集成轴承 9 n. 更新；现代化vt. 更新；校正，修正；使现代化 10 n. 地标，陆标；标志 11 n. 框架，骨架；结构，构架

in a maze returned to mobilise1their foraging2teams，They engaged in contact

sessions3，at the end of which the scout4 was removed in order to observe what her team might do.Often the foragers5 proceeded to the exact spot in the maze where the food had been．Elaborate precautions were taken to prevent the foraging team using odour6 clues．Discussion now centres on whether the route through the maze is communicated as a‘left-right’sequence of turns or as a‘compass7bearing and distance’ message．

During the course of this exhaustive study, Reznikova has grown so attached to her laboratory ants that she feels she knows them as inpiduals-even without the paint spots used to mark them．It’s no surprise that Edward Wilson，in his essay,‘In the company of ants’, advises readers who ask what to do with the ants in their kitchen to：‘Watch where you step．Be careful of little lives’.

1 vt. 动员；调动；使流通 vi. 动员起来

2 n. 觅食

3 n. 会议；会期

4 n. 搜索，侦察；侦察员；侦察机vt. 侦察；跟踪，监视；发现 vi. 侦察；巡视；嘲笑

5 n. 抢劫者；强征队员

6 n. 气味；声誉

7 n. 指南针，罗盘；圆规 vt. 包围

volcanoes-earth-shattering news

When Mount Pinatubo suddenly erupted on 9 June 1991，the power of volcanoes past and present again hit the headlines

A V olcanoes are the ultimate earth-moving machinery．A violent eruption can blow the top few kilometres off a mountain，scatter1 fine ash practically all over the globe and hurl rock fragments2 into the stratosphere 3to darken the skies a continent away.

But the classic eruption-cone-shaped mountain，big bang，mushroom cloud and surges4of molten lava5-is only a tiny part of a global story．Vulcanism6, the name given to volcanic7processes，really has shaped the world. Eruptions have rifted8 continents, raised mountain chains，constructed islands and shaped the topography9 of the earth. The entire ocean floor has a basement10of volcanic basalt．

V olcanoes have not only made the continents，they are also thought to have made the world’s first stable atmosphere and provided all the water for the oceans, rivers and ice-caps．There are now about 600 active volcanoes. Every year they add two or three cubic kilometres of rock to the continents．Imagine a similar number of volcanoes smoking away for the last 3,500million years. That is enough rock to explain the continental crust．

What comes out of volcanic craters11 is mostly gas．More than 90％of this gas is water vapour12 from the deep earth：enough to explain, over 3,500 million years, the water in

1 n. 分散；散播，撒播 vt. 使散射；使散开，使分散；使散播，使撒播

2 n. 碎片；片断；分段v. 破碎；打碎

3 n. 同温层；最上层；最高阶段 4激增 5熔岩 6 n. 岩石火成论者 7 n. 火山岩 adj. 火山的；猛烈的；易突然发作的 8n. 裂缝；不和；[木] 裂口

vt. 使断裂；使分开 vi. 裂开 9地形 10 n. 地下室；地窖 11 n. 火山口；环形山v. 形成坑；毁坏 12 n. 蒸气；水蒸

the oceans. The rest of the gas is nitrogen1，carbon dioxide2，sulphur dioxide3，methane4，ammonia5and hydrogen6.The quantity of these gases, again multiplied7over 3,500 million years，js enough to explain the mass of the world’s atmosphere．We are alive because volcanoes provided the soil，air and water we need．

B Geologists consider the earth as having a molten core，surrounded by a semi-molten mantle and a brittle8，outer skin，lt helps to think of a soft-boiled9 egg with a runny yolk，a firm but squishy11 white and a hard shell．If the shell is even slightly cracked during boiling，the white material bubbles out and sets like a tiny mountain chain over the crack-like an archipelago12of volcanic islands such as the Hawaiian Islands．But the earth is so much bigger and the mantle below is so much hotter,

Even though the mantle rocks are kept solid by overlying13 pressure，they can still slowly‘flow’like thick treacle14.The flow, thought to be in the form of convection currents，is powerful enough to fracture the‘eggshell’of the crust into plates，and keep them bumping and grinding against each other, or even overlapping15，at the rate of a few centimetres a year. These fracture zones, where the collisions16occur, are where earthquakes happen．And，very often，volcanoes．

C These zones are lines of weakness, or hot spots. Every eruption is different, but put at its simplest, where there are weaknesses, rocks deep in the mantle, heated to 1,350。C, will start to expand and rise. As they do so, the pressure drops, and they expand

1氮 2二氧化碳 3二氧化硫 4 ] 甲烷；沼气 5氨 6氢 7 vt. 乘；使增加；使繁殖；使相乘 vi. 乘；繁殖；增加adv. 多样地；复合地 8 adj. 易碎的，脆弱的；易生气的 9 adj. 半熟的 11 adj. 粘糊糊的；湿软的 12 n. 群岛，列岛；多岛的海区 13 adj. 上覆盖的 n. 上覆盖，叠加 14 n. 糖蜜；过分甜蜜的声调 15 v. 与…重叠；盖过（overlap的ing形式）adj. 重叠；覆盖 16 n. 碰撞；冲突；撞击

and become liquid and rise more swiftly.

Sometimes it is slow：vast bubbles of magma-molten-rock from the mantle-inch towards the surface，cooling slowly, to show through as granite extrusions1Lason Skye，or the Great Whin Sill, the lava dyke squeezed out like toothpaste2 that carries part of Hadrian’s Wall in northern England)．Sometimes-as in Northern Ireland，Wales and the Karoo in South Africa-the magma rose faster, and then flowed out horizontally on to the surface in vast thick sheets．in the Deccan plateau3in western India，there are more than two million cubic kilometres of lava, some of it 2,400 metres thick，formed over 500,000 years of slurping eruption.

Sometimes the magma moves very swiftly indeed. It does not have time to cool as it surges4 upwards．The gases trapped inside the boiling rock expand suddenly, the lava glows with heat，it begins to froth5，and it explodes with tremendous force. Then the slightly cooler lava following it begins to flow over the lip of the crater6. It happens on Mars, it happened on the moon, it even happens on some of the moons of Jupiter and Uranus．By studying the evidence，vulcanologists can read the force of the great blasts of the past．Is the pumice7light and full of holes? The explosion was tremendous．Are the rocks heavy, with huge crystalline8basalt shapes，like the Giant’s Causeway9in Northern Ireland? It was a slow, gentle eruption.

The biggest eruptions are deep on the mid-ocean floor，where new lava ls forcing the continents apart and widening the Atlantic by perhaps five centimeters a

1 n. 挤出；挤压制品 2牙膏 3 n. 高原；稳定水平；托盘；平顶女帽 vi. 达到平衡；达到稳定时期 4 n. 突波（surge的复数形式） v. 汹涌；澎湃 5 n. 泡沫，泡；口沫vi. 吐白沫；起泡沫 vt. 使生泡沫 6 n. 火山口；弹坑vt. 在…上形成坑；取消；毁坏vi.

形成坑；消亡 7 n. 浮石；轻石 vt. 用轻石磨；用浮石去污；磨光 8 adj. 透明的；水晶般的；水晶制的

year．Look at maps of volcanoes，earthquakes and island chains like the Philippines and Japan，and you can see the rough outlines1of what are called tectonic2plates-the plates which make up the earth’s crust and mantle．The most dramatic of these is the Pacific ring of fire where there have been the most violent explosions-Mount Pinatubo near Manila，Mount St Helen's in the Rockies and EI Chichon in Mexico about a decade ago，not to mention world-shaking blasts like Krakatoa in the Sunda Straits in 1883．

D But volcanoes are not very predictable3．That is because geological time is not like human time．During quiet periods，volcanoes cap themselves with their own lava by forming a powerful cone from the molten rocks slopping over4the rim of the crater；later the lava cools slowly into a huge，hard，stable plug which blocks any further eruption until the pressure below becomes irresistible5. In the case of Mount Pinatubo，this took 600 years.

Then，sometimes，with only a small warning, the mountain blows its top. It did this at Mont Pelee in Martinigue at 7.49 a.m．on 8 May,1 902.Of a town of 28,000，only two people survived. In 1815，a sudden blast removed the top 1,280 metres of Mount Tambora in Indonesia. The eruption was so fierce that dust thrown into the stratosphere6darkened the skies，cancelling the following summer in Europe and North America．Thousands starved as the harvests failed ,after snow in June and frosts in August．V olcanoes are potentially7 world news，especially the quiet ones.

1 n. 轮廓；大纲；概要；略图 vt. 概述；略述；描画…轮廓

2 adj. [地质] 构造的；建筑的；地壳构造上的 3可预测的4喷溅在5 adj. 不可抵抗的；不能压制的；极为诱人的 6 n. 同温层；最上层；最高阶段 7 adv. 可能地，潜在地

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