时间:2019-01-02 作者:英语课 分类:60秒科学


英语课

Mosquitoes, Not Birds, Made West Nile National


In 1999 West Nile virus infected its first American, in New York. By 2004, the disease had spread across the country. Researchers speculated that, for the disease to spread so far so quickly, birds must have helped. Some species could carry the disease and pass it on to mosquitoes, which would then infect humans. But a report published March 2nd in the journal Molecular 1 Ecology [not available online as this episode was posted] says mosquitoes didn’t need a middleman. Or in this case, a middle bird.


Researchers [Jason Rasgon, Bloomberg School of Public Health, Johns Hopkins and Meera Venkatesan, Howard Hughes Medical Institute] noticed that West Nile virus didn't move north-south along migratory 2 bird routes. Nor did it "leap frog" across large areas in the manner of a bird traveling far from where it was infected.


The scientists focused on a different suspect and obtained mosquito DNA 3 from 20 sites in the western U.S. They found three clusters of a species known to carry West Nile.


Surprisingly, they found extensive gene 4 flow between these populations, which meant mosquitoes traveled between groups. In some cases, these mosquitoes covered a range just as large as that of the birds first fingered in the outbreak. So bird lovers take heart, your feathered friends are innocent avians.

 



adj.分子的;克分子的
  • 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。
n.候鸟,迁移
  • Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
  • This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。
(缩)deoxyribonucleic acid 脱氧核糖核酸
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
n.遗传因子,基因
  • 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。
学英语单词
a chip in pottage
accounting ethics
acid rain
aeshma
afaf
ahmer
altitude track
arthralgia-synadrome
attribute record
avalanche of massive snow
beheaders
bellatrice
binoquercetin
blacksheep
car-pooled
Chilumba
classification number
close milk filter
coalface support
cold resistivity
counter-doping
crossed card
cyclopel
cyclopentanoperhydrophenanthrene ring
damage variable
decode scaler
decomplier
denoised
designated compliance officer
difference Fourier method
dizirconyl
draft test
Dual Filing Advisory Group
electric bridge crane
epithiazide
eragrostis cylindrica
Eubolin
extinction of crime
ferritisey
field of view (fov)
fiks
fire detection
fore-piece
frangility
galipot (resin)
global optimal solution
haanas
handle setting plate
handsdown
hoople
hydrophabia
I region
Joseph I
laparoenterostomy
light rings
limiting test
loop checking system
Lord love you !
male wrench
medico paper
memory density
mesophytic environment
multiformat camera
music departments
nesophitic
nocturnal enuresis
nonresident tax-payer
orbit transfer rocket engine
overhead-valve
perchlorofluoromethane
Phenhenzamine
pl/i-formac
polynomial algebra
radial flow centrifugal pump
reactor power meter
rust roofing
Saccharomyces exiguus
seeman
shortland islands
skin care agent
slip nooses
slow burning
soil succession
spinal accessories
spirochaetal disease
subjective fremitus
sulfo
Tartu
the Federal Reserve Board
thematic flexion
thermal-oxidative plasticization
tie coat
tole-rants
torshear type high strength bolt
Vidzeme
vrock
Whitmore's bacillus
wild China tree
wirecut EDM