英文阅读:蓝色光的生物效应

Blue light can both set the mood and set in motion important biological responses. Researchers at the University of Pennsylvania's School of Medicine and School of Arts and Sciences have teased apart the separate biological responses of the human eye to blue light, revealing an unexpected contest for control. Their work addresses the properties of melanopsin, a light-sensitive protein in the eye that establishes the rhythm of our day-night cycle and the familiar constriction1 of the pupil to bright light. They measured the pupil response to stimulation2 of melanopsin and of short-wave-sensitive (S) cones3, the other blue light-sensing cells that operate in daylight. Surprisingly, they found that melanopsin and S-cones have opposite effects and compete for control of the pupil in blue light. Their complete results are published in the current issue of PNAS. Drs. Aguirre and Brainard and graduate student Spitschan found that melanopsin, a protein and short wave-sensitive S-cones, both in the retina have opposite effects and compete for control of the pupil in response to blue light.

"The challenge of studying melanopsin is that it is very sensitive to blue light, a short-wave light emitted by digital devices including smartphones, tablets, and computers, as are S-cones," says lead author, Manuel Spitschan, a Penn graduate student in psychology4. "Previous studies in the human eye have not separately studied the S-cones and melanopsin because flashing a blue light stimulates5 both of these cells, so we didn't know if what a person saw or the response of the pupil was from one or both." To overcome this problem, the Penn team developed a special class of visual stimuli6: they produced flickering7 light that stimulates melanopsin but is invisible to S-cones, and a second flickering light that stimulates S-cones but is invisible to melanopsin. The lights were created using a machine that can sculpt8 and switch between computer-designed rainbows of light.

The researchers had 16 people watch this flickering light while the response of their pupil was recorded. The light that stimulates melanopsin made the pupil slowly contract. To their surprise, they also discovered that stimulation of S-cones made the pupil get larger. That is, when the S-cones of the eye captured more light, the pupil enlarged, the opposite of what is generally thought of as the natural pupil response. This means that blue light sets off a tug-of-war between melanopsin and S-cones to make your pupil smaller or bigger. The melanopsin effect is stronger, resulting in the familiar shrinking of the pupil to bright light of any color.

词汇表：

1 constriction

压缩； 紧压的感觉； 束紧； 压缩物

参考例句：

She feels a constriction in the chest. 她胸部有压迫感。

If you strain to run fast, you start coughing and feel a constriction in the chest. 还是别跑紧了，一咬牙就咳嗽，心口窝辣蒿蒿的！ 来自汉英文学 - 骆驼祥子

2 stimulation BuIwL

n. 刺激，激励，鼓舞

参考例句：

The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。

You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。

3 cones

n. （人眼）圆锥细胞；圆锥体( cone的名词复数 )；球果；圆锥形东西；（盛冰淇淋的）锥形蛋卷筒

参考例句：

In the pines squirrels commonly chew off and drop entire cones. 松树上的松鼠通常咬掉和弄落整个球果。 来自辞典例句

Many children would rather eat ice cream from cones than from dishes. 许多小孩喜欢吃蛋卷冰淇淋胜过盘装冰淇淋。 来自辞典例句

4 psychology

n. 心理，心理学，心理状态

参考例句：

She has a background in child psychology.她受过儿童心理学的教育。

He studied philosophy and psychology at Cambridge.他在剑桥大学学习哲学和心理学。 5 stimulates

v. 刺激( stimulate的第三人称单数 )；激励；使兴奋；起兴奋作用，起刺激作用，起促进作用

参考例句：

Exercise stimulates the body. 运动促进身体健康。 来自《简明英汉词典》

Alcohol stimulates the action of the heart. 酒刺激心脏的活动。 来自《现代英汉综合大词典》

6 stimuli

n. 刺激（物）

参考例句：

It is necessary to curtail or alter normally coexisting stimuli.必需消除或改变正常时并存的刺激。

My sweat glands also respond to emotional stimuli.我的汗腺对情绪刺激也能产生反应。 7 flickering

adj. 闪烁的，摇曳的，一闪一闪的

参考例句：

The crisp autumn wind is flickering away. 清爽的秋风正在吹拂。

The lights keep flickering. 灯光忽明忽暗。

8 sculpt

n. 雕刻，雕塑，雕刻品，雕塑品

参考例句：

When I sculpt,my style is expressionistic.我的雕刻风格是表现主义。

Then,sculpt the remaining fringe parting.然后雕刻剩余的边缘部分。

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