Last year I ruined my summer vacation by bringing along a modern convenience that was too convenient for my own good: the iPad. Instead of looking at nature, I checked my e-mail. Instead of paddling a small boat, I followed my Twitter feed (推特简讯). Instead of reading great novels, I stuck to reading four newspapers each morning. I was behaving as if I were still in the office. My body was on vacation, but my head wasn't.

So this year I made up my mind to try something different: withdrawal (退出) from the Internet. I knew it wouldn't be easy, since I'm bad at self-control. But I was determined. I started by giving the iPad to my wife.

    The cellphone signal at our house was worse than in the past, making my attempts at cheating an experience in frustration (沮丧). I was trapped, forced to go through with my plan. Largely cut off from e-mail, Twitter and my favorite newspaper websites, I had few ways to connect to the world except for the radio—and how much radio can one listen to, really? I had to do what I had planned to do all along: read books.

This experience has had a happy ending. With determination and the strong support of my wife, I won in my vacation struggle against the Internet, realizing finally that it was I, not the iPad, that was the problem. I knew I had won when we passed a Starbucks and my wife asked if I wanted to stop to use the Wi-Fi. “I don't need it,” I said.

However, as we return to post-vacation life, a harder test begins: Can I continue when I'm back at work?

There are times when the need to know what's being said right now is great. I have no intention of giving up my convenience completely. But I hope to resist the temptation (诱惑) to check my e-mail every five minutes, which leads to checking my Twitter feed and a website or two.

    I think a vacation is supposed to help you reset your brain to become more productive. Here I hope this one works.

    Larger brain size linked to longer life in deer. The size of a female animals' brain may determine whether they live longer and have more healthy later generations, according to new research led by the University of Cambridge.

    The study, published in the Royal Society Open Science journal, shows that female red deer with larger brains live longer and have more surviving later generations than those with smaller brains. Brain size is heritable and is passed down through the generations. This is the first extensive study of individual differences in brain size in wild mammals and draws on data comparing seven generations of deer.

    Across species of mammals, brain size varies widely. This is thought to be a consequence of specific differences in the benefits and costs of a larger brain. Mammals with larger brains may, for example, have greater abilities that enable them to adapt better to environmental changes or they may have longer lifespans. But there may also be disadvantages: for instance, larger brains require more energy, so individuals that possess them may show reduced ability to give birth to young babies.

    The researchers, based at the University of Cambridge's Zoology Department and Edinburgh University's Institute of Evolutionary Biology, wanted to test if they could find more direct genetic or non-genetic evidence of the costs and benefits of large brain size by comparing the longevity(长寿) and survival of individuals of the same species with different sized brains. Using the skulls of 1,314 wild red deer whose life histories and breeding success had been monitored in the course of a long-term study on the Isle of Rum, they found that females with larger endocranial volumes(脑腔容量) lived longer and produced more surviving offspring in the course of their lives.

    Lead author Dr Corina Logan, a Gates Cambridge Scholar, says, "The reasons for the association between brain size and longevity are not known, but other studies have suggested that larger brains are a consequence of the longer-lived species having longer developmental periods in which the brain can grow. These predictions were generated from cross-species correlations; however, testing such hypotheses requires investigations at the within-species level, which is what we did. "

    Dr Logan adds, "We found that some of the cross-species predictions about brain size held for female red deer, and that none of the predictions were supported in male red deer. This indicates that each sex likely experiences its own set of trade-offs(权衡,协调) with regard to brain size. "The study also showed that females' relative endocranial volume is smaller than that of males, despite evidence of selection for larger brains in females.

    Professor Tim Clutton Brock, who set up the Rum Red Deer study with Fiona Guinness in 1972 and started the work on brain size, points out, "The reason that this kind of study has not been conducted before is that it requires long term records of a large number of individuals across multiple generations and data of this kind are still rare in wild animals."

    TALENT ON PARADE

    It is time for the Smithdale Student Activity Club's yearly talent show. In the past, the club has had performers sing, dance, and play the violin, guitar, or piano. This year the show will be called "Talent on Parade", and we are looking for performers with great new ideas. In addition, we have planned two important changes for this year's show.

    Two Shows Instead Of One

    First, "Talent on Parade" will be held on two nights. Performers in the Wednesday night show will include students in Grades K-5. Performers in the Friday night show will include students in Grades 6-12.

    Smithdale High School Hall Wednesday, May 11, 6:30 P.M. Friday, May 13, 7:30 P.M.

    No Tryouts (预选)

    The second change is that this year's performers will be chosen in a new way. No tryouts will be held. The first twenty acts to sign up for each show will be accepted. Others will be put on a waiting list in case someone has an act that is not allowed. You'll be told by telephone or e-mail if your act is included.

    If you do not wish to perform but would enjoy helping backstage with lights or sound, print "stagehand" in large letters at the top of the permission slip (同意书).

    Rules For Acts

    ⒈Each student chosen to perform must turn in a permission slip signed by a parent or guardian(监护人).

    ⒉All performers must be at the school one hour before the show time.

    ⒊Performers must provide their own transportation to and from the school.

    ⒋Each act is limited to three minutes.

    ⒌No act may have more than five people in it.

    ⒍Performers must provide their own music (tapes, CDs, or instruments) and costumes.

    ⒎Singers may sing with or without musical accompaniment, but they may not sing along with a recorded voice on a CD or tape.

Dear Alcohol,

    You've been around forever. I can remember all the pain you've caused for me.

    Do you remember the night you almost took my father's life? I do. He loves you. Sometimes I think he loves you more than he loves me. He's addicted to you, to the way you promise to rid him of his problems only to cause more of them. You just sat back and laughed as his car went spinning through the street, crashing into two other cars. He wasn't the only one hurt by you that night.

    Do you remember the night of my first high school party? You were there. My friends were intrigued by you. They treated you as if they were never going to see you again, drinking all of you that they could. I spent two hours that night helping my friends who had fallen completely. "I'm so embarrassed," they said as I held their hair back so that they could vomit. "I'm sorry," they said when I called taxies for them, walking them out and paying the driver in advance. "This won't happen again," they said as they were sent to the hospital to have their stomachs pumped. Two 15-year-old girls slept in hospital beds that night thanks to you.

    Do you remember the night when you took advantage of my 17-year-old neighbor who had to drive to pick up his sister from her dance lessons? Do you know how we all felt when he hit another car and killed the two people in the other car? He died the next morning too. His sister walked home from her dance lesson, and passed police cars and a crowd of people gathering on the sidewalk just two blocks away from the dance studio. She didn't realize her brother was in the midst of it all. She never saw him again. And it's all your fault.

    I wish you'd walk out of my life forever. I don't want anything to do with you. Look at all the pain you've caused. Sure, you've made people happy too from time to time. But the damage you've caused in the lives of millions is inexcusable. Stop luring (引诱) in the people I love. Stop hurting me, please.

Sincerely,

Me

    Welcome to iusEnglish, a wonderful online school that specializes in teaching English to school, aged Chinese children from seven to fifteen. We offer lessons focusing on English reading and writing. Because of the rapid growth of our school, we are now looking for more qualified（合格的）teachers to join us to teach 3rd & 4th grade.

    Online Teachers for 3rd & 4th Grade Reading and Writing Classes

    •Teach 3rd & 4th grade reading classes in an online environment ;

    •The students are Chinese children who are able to communicate in English ;

    •Class schedule will be set up according to teachers' time frame ;

    •Teachers are expected to create lessons and grade students' homework ;

    •40 minutes for a class and one class meeting once a week.

    Desired Skills & Experience

    •A recognized degree and a teaching qualification at the graduate level ;

    •Those with the teaching background in elementary school are highly preferred ;

    •Ability to plan, deliver and motivate students to learn;

    •Strong communication skills to work with cooperation ;

    •Native American English speakers ;

    •Be able to create lessons and prepare lesson plans ;

    •Love teaching! Patience, self­management, positive attitude, and most of all, be devoted ;

    • Two ­year experience in teaching online or in classroom circumstances for programming teachers.

    Teachers are able to work from the comfort of their own homes in the hours and days of their choosing. The benefits of joining iusEnglish are great. Besides earning extra income, teachers are rewarded by watching the continual progress of their students week by week. It' s a win­win situation, and we hope you will consider joining our team.

    Don't hesitate. Please contact us: ius@iusEnglish.com.

Steager is an engineer at the University of Pennsylvania. His colleague Hyun Koo is an inventor and dental researcher there. Together, they found a way to form the nanoparticles（纳米颗粒）into long, skinny bristles（鬃毛）, a lot like the ones on a toothbrush. But these bristles shape-shift to fit whatever surface they encounter. They can even squeeze between teeth.

"A new way to clean teeth could help out anyone who finds this chore boring," says Koo. But it would be especially life-changing for people with disabilities or illnesses that make it difficult or impossible to hold and move a toothbrush.

The tooth-cleaning robot works thanks to two magnets（磁铁）. One goes on each side of the teeth. The nanoparticles sit in a water-based solution between the magnets. When the magnets are turned off, the nanoparticles float randomly in the solution. As soon as one magnet gets turned on, the nanoparticles clump together near its center. When you turn on the other magnet and turn off the first one, the nanoparticles extend outward in long, skinny bristles.

When there's a tooth in the way, these bristles can't stretch out as far as they want. So they push against the tooth's surface. If there's a gap between teeth, they push into the gap. Moving the magnets makes the bristles move against and between teeth.

Besides, as a bonus, the nanoparticles can kill what harms the teeth and keep them health y because it contains something commonly added to toothpaste and mouthwash.

The new invention is just a proof of concept. The researchers still need to turn it into a product that people will want to use. It must fit comfortably and safely in people's mouths. It can't draw too much power or cost too much. "There's a lot of engineering to get from here to there," says Steager. But he adds, "every good idea needs to have a start."