VOA慢速英语2013 科学家说空气污染威胁着蜜蜂

 

AS IT IS 2013-11-01 Scientists Say Air Pollution Threatens Honeybees 科学家说空气污染威胁着蜜蜂

From VOA Learning English this is As It Is.

Welcome back. I’m Caty Weaver¹. Today, we go to a school near Washington where meals are being served up fresh and healthy.

But first, we talk about the health of a very good friend to farmers: the honeybee. Pollution from diesel²-powered vehicles could be harming the insect’s sense of smell.

Bees are important to human beings. The insects pollinate about 70 percent of the world’s food crops. But honeybees are in real trouble. Each year, about one-third of bee hive populations are destroyed by a mysterious disease called colony collapse³ disorder⁴.

Scientists have found several reasons for the falling number of honeybees -- from poor hive care to parasitic⁵ organisms. But a new study suggests that air pollution also might be a cause. Avi Arditti reports.

Air Pollution: Honeybee Hazard

Imagine a honeybee’s world: the insect depends on its eyesight and sharp sense of smell to pollinate plants.

“Now, it’s faced with a sea of chemistry every time it goes out on a foraging⁶ expedition. So what it has to do is decipher and discern between those different chemicals to home in on the plants that it knows are going to give it the best reward in terms of nectar and pollen⁷.”

That is Tracey Newman, a neurobiologist at Britain’s University of Southampton. She served as lead investigator⁸ of the new study.

She says the honeybee uses smell to find, identify and recognize the flowers they like. She says her team wanted to learn how pollutants⁹ might affect that process. Their study asks this question:

“If you have flowers and flower volatiles – flower perfumes – coming off an environment that is polluted, is the bee compromised in any way in its ability or its effectiveness to find the flowers that it’s looking for? And in particular, what we wanted to know is not the direct impact on the bee itself, but on the flower chemistry that the bee is having to find.”

Bees find these flowers by memorizing scents¹¹ in the environment. The researchers used honeybees in controlled laboratory experiments. The bees were taught to link the smell of rapeseed flowers with nectar. Then, Ms. Newman says, the researchers added diesel exhaust to the mix. They wanted to see how well the bees could identify the smell in the polluted air.

“And (we) saw marked changes in the responses of the bees to that new, newly altered scent¹⁰. The response rate in the bees went down to only a quarter of the original learned response.”

The scientist says nitric oxides in diesel fuel waste reacted with chemicals from the flower and changed or destroyed them. That process puts already troubled beehives even more at risk. Ms. Newman says the influence of diesel exhaust had never before been noted¹² in connection with honeybee health, until now.

“However, if you think of a situation, which isn’t hard to imagine, where a bee is dealing¹³ with viral infections, mite¹⁴ infections, all the other stresses it has to deal with, another thing that makes it harder for the bee to work in its environment, so adds to that list of stresses, is likely to have detrimental¹⁵ consequences.”

Tracey Newman and her team have begun field studies to see if they can reach similar findings in the wild. Their report was published in the Nature journal Scientific Reports.

I’m Avi Arditti.

You are listening to As It Is, from VOA Learning English.

Students Enjoy Fresh Food from Local Farms

We recently visited the Ruth Ann Monroe Primary School during lunch. The students lined up for a serving of roast pork. The meat came from a local farm.

Jeffrey Proulx leads the food and nutrition services department for all the public schools in Washington County, Maryland.

“We’ve also got local apples. Today’s feature is a Golden, or a Yellow Delicious. This is from an orchard¹⁶ here in Smithsburg, from Rinehart Orchards¹⁷.”

Rinehart Orchards supplies about 85 percent of the apples for the County’s schools. The business is part of a growing number of farm-to-school partnerships¹⁸ in the United States.

American public schools feed more than 30 million boys and girls a day. About 20 million of them come from poor families. They depend on federal money for their school meals.

Jeffrey Proulx says most schools do not cook fresh meals anymore.

“We have gone to, really, box-to-oven products. Fully¹⁹ processed, prepared items that are more heat-and-serve. So, we are definitely taking a stretch back to our roots, which is, actually, cooking food.”

Many experts say processed school meals are adding to the nation’s childhood obesity²⁰ problem. But new government rules aim to make school food healthier. Mr. Proulx says fresh foods make it easier to lower the levels of salt and fat in a child’s diet.

“The way to reach those levels is to prepare it ourselves, and to really control what is in the product by sourcing it ourselves.”

And buying from nearby farms also helps the local economy, says orchards owner J.D. Rinehart.

“That enables us to update our facilities, to buy equipment locally. Keeping the money right here in the region is huge, not only for us but for the people that benefit from us purchasing.”

Mr. Rinehart says it also just makes good business sense.

“Your transportation cost is low. And you don’t have to go to use a broker²¹ or a seller that will take a commission off of you.”

Money stays in the local economy and school kids get fresh food. It is easy to see why farm-to-school programs have spread fast. In 1997, six American states had such programs. Now all 50 states include them.

But the United States is not the world leader in the movement. Carmen Burbano is with the World Food Program. She says Brazil is the biggest farm-to-school success. It is linked to the “zero-hunger” anti-poverty policy of former President Luis Inacio Lula da Silva.

“One of the cornerstones of that plan was the school feeding program. But in 2009, they realized that this program, which was costing the government quite a bit of money, could also help to connect that program with family farmers.”

The program now requires that 30 percent of school meals come from local farmers. It has been so successful that Brazil is now helping²² several African countries set up their own programs to help young students and farmers.

And that’s As It Is for today.

1 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

2 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。

3 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

4 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

5 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

6 foraging   

v.搜寻（食物），尤指动物觅（食）( forage的现在分词 )；（尤指用手）搜寻（东西）

参考例句：

• They eke out a precarious existence foraging in rubbish dumps. 他们靠在垃圾场捡垃圾维持着朝不保夕的生活。 来自《简明英汉词典》
• The campers went foraging for wood to make a fire. 露营者去搜寻柴木点火。 来自辞典例句

7 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

8 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

9 pollutants   

污染物质（尤指工业废物）( pollutant的名词复数 )

参考例句：

• Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
• The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条（g）的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

10 scent   

n.气味，香味，香水，线索，嗅觉；v.嗅，发觉

参考例句：

• The air was filled with the scent of lilac.空气中弥漫着丁香花的芬芳。
• The flowers give off a heady scent at night.这些花晚上散发出醉人的芳香。

11 scents   

n.香水( scent的名词复数 )；气味；（动物的）臭迹；（尤指狗的）嗅觉

参考例句：

• The air was fragrant with scents from the sea and the hills. 空气中荡漾着山和海的芬芳气息。
• The winds came down with scents of the grass and wild flowers. 微风送来阵阵青草和野花的香气。 来自《简明英汉词典》

12 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

13 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

14 mite   

n.极小的东西；小铜币

参考例句：

• The poor mite was so ill.可怜的孩子病得这么重。
• He is a mite taller than I.他比我高一点点。

15 detrimental   

adj.损害的，造成伤害的

参考例句：

• We know that heat treatment is detrimental to milk.我们知道加热对牛奶是不利的。
• He wouldn't accept that smoking was detrimental to health.他不相信吸烟有害健康。

16 orchard   

n.果园，果园里的全部果树，(美俚)棒球场

参考例句：

• My orchard is bearing well this year.今年我的果园果实累累。
• Each bamboo house was surrounded by a thriving orchard.每座竹楼周围都是茂密的果园。

17 orchards   

（通常指围起来的）果园( orchard的名词复数 )

参考例句：

• They turned the hills into orchards and plains into granaries. 他们把山坡变成了果园，把平地变成了粮仓。
• Some of the new planted apple orchards have also begun to bear. 有些新开的苹果园也开始结苹果了。

18 partnerships   

n.伙伴关系( partnership的名词复数 )；合伙人身份；合作关系

参考例句：

• Partnerships suffer another major disadvantage: decision-making is shared. 合伙企业的另一主要缺点是决定要由大家来作。 来自英汉非文学 - 政府文件
• It involved selling off limited partnerships. 它涉及到售出有限的合伙权。 来自辞典例句

19 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

20 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。

21 broker   

n.中间人，经纪人；v.作为中间人来安排

参考例句：

• He baited the broker by promises of higher commissions.他答应给更高的佣金来引诱那位经纪人。
• I'm a real estate broker.我是不动产经纪人。

22 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。