Alien invaders
Collected by Lily

加拿大一枝黄花、水葫芦、巴西龟等外来入侵物种, 正逐渐影响着我们的生态和生存环境, 我国每年因此造成的损失已达1300亿元. 什么是外来入侵物种? 为什么要引进它们? 怎样控制它们进一步蔓延?

Have you ever imagined that beautiful ornamental plants and animals such as Solidago Canadensis, the water hyacinth and the Brazilian turtle are imposing great danger on the ecosystem and our living environment? They are killers of their neighboring species and a latent threat to our health. Invasive alien species are species introduced deliberately or unintentionally outside their natural habitats where they have the ability to establish themselves, invade, outcompete natives and take over the new environments. They are widespread in the world and are found in all categories of living organisms and all types of ecosystems. However, plants, mammals and insects comprise the most common types of invasive alien species in terrestrial environments.



The threat to biodiversity due to invasive alien species is considered second only to that of habitat loss. They are thus a serious impediment to conservation and sustainable use of global, regional and local biodiversity, with significant undesirable impacts on the goods and services provided by ecosystems. Biological invasions operate now on a global scale and will undergo a rapid increase in this century due to interactions with other global changes such as increasing globalization of markets, explosive rises in global trade, travel, tourism, and exchange of goods.



Invasive alien species can cause a significant irreversible environmental and socio-economic impact at the genetic, species and ecosystem levels. Their management costs include not only costs of prevention, control and mitigation, but also indirect costs due to impacts on ecological services. Environmental and socio-economic impacts of harmful invasive alien species are already being felt: Filipino rice farmers have lost nearly US$ 1 billion in crops to the invasive golden apple snail. Alien water weeds, like the water hyacinth and water lettuce are a global problem; African nations alone spend an estimated US$ 60 million annually on their control. International trade has introduced the Asian tiger mosquito- which carries dengue fever- to the Americas and Africa, and has spread the life-threatening bacteria Escherichia coli in meat exports. Up to now there are about 400 invasive alien species. As a result, China suffers a loss of over 130 billion RMB every year. Among them Solidago Canadensi, the water hyacinth, the Brazilian turtle, Ageratina adenophora are some of the most popular ones. There is an urgent need to address the impact of invasive alien species. Eradication, control, mitigation of their impacts combined with legislation and guidelines at national, regional and international levels to take close control of their introduction are some of the ways to prevent them from further spreading and invading.

Vocabulary
solidago Canadensis 加拿大一枝黄花
Brazilian turtle 巴西龟
ipomoea nil 牵牛花
water hyacinth 水葫芦
terrestrial 地球上的
impediment 阻碍
dengue 登革热
animalcule 微生物
Mercury 水星
polio 小儿麻痹症
chicken pox 水痘
smallpox 天花
measles 麻疹
hippopotamus 河马
warthog 疣猪(一种非洲野猪)

Science Harbor

Anti-AIDS drug claims "breakthrough"
抗艾滋病新药有突破
Early clinical trials conducted at two Beijing hospitals allegedly show a new medication developed by a Chinese medical company may effectively increase immune cells in AIDS patients and relieve symptoms of the deadly disease. After at least one month, when AIDS patients should take at least two dosages a day, AIDS symptoms are significantly relieved and lives prolonged. But the medication is unable to kill HIV virus, and is still not available on Chinese markets.



Samsung NAND chips lead to memory price cuts
三星芯片问世闪存卡价格下降
Samsung Electronics has begun to produce its first NAND flash memory chips using 70 nanometer process technology, a move which analysts say will help lower the cost of memory cards. Memory chips produced by the more advanced process are smaller, faster, and less expensive than those made with the industry-standard 90 nm process. NAND flash is a type of flash memory commonly used in memory cards and in MP3 players. The lower chip prices could lead to memory cards retailing for about a fifth less at the end of the year compared to what they cost now.



China to launch 1st "seed satellite"
中国发射首枚"种子卫星"
The "seed satellite" project consists of satellite research and development, launch and recovery, seed breeding, mechanism research and simulation tests. In space seed-breeding, seeds and animalcule are sent into space about 200 to 400 km away from the earth in recoverable satellites or recoverable space vehicles and are exposed to cosmic radiation, micro-gravity, high vacuum, alternating magnetic fields and other special factors to cause useful mutation that is hard to obtain on the earth.

3G mobile telecom services available before 2008
2008年前第三代手机电信服务可开通
Third-generation (3G) mobile telecommunications technology will begin to serve in China, the world's largest mobile telecom market, before 2008. There are now 349 million subscribers to mobile telecom services in China, the most in the world. The total includes 319 million subscribers to GSM (global system for mobile telecommunications), and 30 million to CDMA (code division of multiple access) system.

QUIZ

1. How much of your vision do you lose if you go blind in one eye?
A 50 percent
B 10 percent
C 35 percent
D 20 percent

2. Which statement fits a day with a temperature of 68 degrees Fahrenheit?
A sweltering
B freezing cold
C chilly
D mild and lovely

3. The hottest temperature in the solar system was recorded on this planet:
A Mars
B Jupiter
C Venus
D Mercury

4. What was the first disease conquered by human beings?
A Polio
B Chicken pox
C Smallpox
D Measles

5. Which land mammal is most closely related to the whale?
A Hippopotamus
B Fur Seal
C Warthog
D Elephant