The crisis at the damaged Fukushima Dai-Ichi Nuclear Power Station in northern Japan has raised worries about radiation risks. We spoke Tuesday with Jonathan Links, an expert in radiation health sciences. He is a professor at the Johns Hopkins Bloomberg School of Public Health in Maryland.

Professor Links says workers within the nuclear plant are the only people at risk of extremely high doses of radiation.

JONATHAN LINKS: “Of course, we don’t know what doses they’ve received, but the only persons at risk of acute radiation effects are the workers.” For other people, he says, there may be a long-term worry. People can get cancer from low doses of ionizing radiation, the kind released in a nuclear accident.

Professor Links says scientists can use computers to quickly model where radioactive material has blown and settled. Then they measure how large an area is contaminated. He says if the situation is serious enough, officials could take steps like telling people not to eat locally grown food or drink the water.

JONATHAN LINKS: “But that would only be the case if there was a significant release and, because of wind direction, the radioactive material was blown over the area, and then settled out of the air into and onto water, plants, fruits and vegetables.”

The reactors at Fukushima are on the Pacific coast. But Professor Links says people should not worry about any radioactive material leaking into the ocean.

JONATHAN LINKS: “Even in a worst-case scenario accident, the sea provides a very high degree of dilution. So the concentration of radioactivity in the seawater would still be quite low.”

Japan is the only country to have had atomic bombs dropped on it. That memory from World War Two would create a stronger “psychological sensitivity” to radiation exposure, Professors Links says.

Next month is the twenty-fifth anniversary of the explosion and fire that destroyed a reactor at Chernobyl in Ukraine. The nineteen eighty-six event was the world’s worst accident in the nuclear power industry.

A new United Nations report says more than six thousand cases of thyroid cancer have been found. These are in people who were children in affected areas of Belarus, Russia and Ukraine. The report says that by two thousand five the cancers had resulted in fifteen deaths.

The cancers were largely caused by drinking contaminated milk. The milk came from cows that ate grass where radioactive material had fallen.

To get the latest updates, go to www.unsv.com.

Contributing: James Brooke

【推荐3】Often people receive a guitar, mandolin, or some other musical instrument as a birthday or Christmas gift. There's joy everywhere. The giver of the gift knows how much the receiver wants to learn this instrument and the receiver is actually holding it in his hands instead of longing for it through the shop window.

Finding an instructor that fits into a busy work schedule is hard enough, but once you decide on a lesson plan, then you must consider the practice time, how to practice, what to practice—and let's face it...not all people learn something the same way. So in order to learn a musical instrument, how much practice time is enough and what kind of practice is right for you?

There is no set amount of time that anyone should practice a musical instrument. When I was in programming classes, I could have studied nightly for 5 hours each night. It would have taken me years to learn the art of computer programming. Though I'm attracted by the systematic logic of it, my talent is towards another thing. However, on the other hand, if I spent an hour every couple days with a passionate hobby like playing the violin, not only would the time fly quickly...I'd also be learning at a much greater speed since the built-in passion is the motivation for advancement.

So as much as it's important to practice, a step back is to first find the harmonious instrument that fits you as a person; as development of your personality. If you're learning the guitar because it's cool....obviously that's the modern-day mindset, however, you might not be actually linking your talent for musical satisfaction with your most creative advantages you have to offer.

It's been my experience that every person has a certain level of musical talent. My pleasant challenge has been to assist them in this adventure and actually locate their best abilities as quickly as possible. Then and only then can we match learners with instruments and truly begin a fun and exciting walk down the road of happiness and contentment, where music, ability, personality and soul all meet. Once this piece of the mystery puzzle is in place, I've never had to work at motivating a learner to practice...

【推荐1】You're probably used to the periodic upgrades in our cellphone networks. There was 2G, which came along in 1991, replaced with 3G in 2001, and followed by 4G in 2009.Now we're hearing about the coming of 5G.

But 5G is a much bigger leap than what's come before. Of course, 5G is much faster than 4Gin the real world. A 5G phone in a 5G city will enjoy Internet speeds between nine and 20 times as fast. The arrival of 5G also means enormous leaps forward in capacity so much that every cell-phone plan will offer cheap, truly unlimited Internet access.

For example, apps will no longer degrade your video or postpone downloading when you're out of Wi-Fi range. Furthermore, our phones can become more powerful. Today the processors in our devices are limited by heat and battery capacity. But imagine, Hanna says, if your phone is tied, by a 5G connection, to a much more powerful computer online. “It's happening remotely, but because it's such a high-speed connection, it will feel as though the additional processor is inside your device, in your hand,” he says.

Not everyone is thrilled by the 5G development. The new standard gets its speed partly by using existing transmission frequencies more efficiently. These frequencies are much higher than anything we've used for cellular, which means they can offer unbelievable speed but at the expense of range. Mill-meter-wave cellular towers(毫米波峰窝塔) have to be about 500 feet apart. Cell carriers not only will have to upgrade all their cell transceivers(收发器) but will install a lot more of them as well. That's why the millimeter-wave flavor of 5G will be available only in densely populated cities such as New York.

The need to install more small cells means more rectangular boxes on lampposts, and more industrial-looking ugliness in places where local residents don't always want it. But 5G is a train that can’t be stopped.

Here's to all those engineers and their millimeter waves. Someday we'll tell our grand kids about the days when YouTube videos paused annoyingly, and the only way cars could communicate was by honking.

【推荐3】Technology seems to discourage slow reading. Reading on screens tires eyes easily. So online writing is more skimmable than print. The neuroscientist Mary Walt argued this “new norm” of skim reading is producing “an invisible, dramatic transformation” in how readers process words. And brains now favor rapid absorption of information, rather than skills developed by deeper reading, like critical analysis.

We shouldn’t overplay this danger. All readers skim. Skimming is the skill we acquire as we learn to read more skillfully. And fears about declining attention spans have proved to be false alarms. “Some critics worry about attention span and see very short stories as signs of cultural decline, ” The American author Selvin wrote. “But nobody ever said poems were evidence of short attention spans. ”

Yet the Internet has certainly changed the way we read. First, it means there’s more to read, because more people than ever are writing. And digital writing means rapid release and response. Once published, online articles start forming a comment string underneath. Such mode of writing and reading can be interactive and fun, but is probably lacking in profound reflection.

Perhaps we should slow down. Reading is constantly promoted as a source of personal achievement. But this advocacy emphasizes “enthusiastic” or “eager” reading — neither suggest slow absorption. To a slow reader, a piece of writing can only be fully understood by immersing oneself in their slow comprehension of words. The slow reader is like a swimmer who stops counting the number of pool laps he’s done and just enjoys how his body feels and moves in water.

The human need for this kind of deep reading is too determined for any new technology to destroy. We often assume technological change can’t be stopped, so older media are kicked out by newer, more virtual forms. In practice, older technologies can coexist with new ones. The Kindle hasn’t killed off printed books any more than cars killed off bicycles. We still want to enjoy slowly-formed ideas and carefully-chosen words. Even in a fast-moving age, there is time for slow reading.