As soon as a person dies, decomposition(分解) begins. And the first visitors arrive. “Within 5 to 15 minutes of death, flies or other insects begin to colonize the body.” says Rabi Musah, an organic chemist at the University at Albany.

    She says different species turn up at different stages of decomposition. “So because of that, depending upon what entomological(昆虫学的) evidence you find, you can learn something about when the person died in terms of the timing of the death.”

    Flies don't tend to stick around when disturbed by detectives. But they do leave behind eggs. The eggs are hard to tell apart by appearance alone, so specialists raise them until they hatch, a few weeks later—and they get a species ID and, with a little guesswork, a person's time of death.   But Musah has come up with a more time-saving approach: chemical analysis of the eggs. She and her team investigated that method by first harvesting flies with pig-liver traps hidden throughout New York City. They collected the trapped flies and then chemically analyzed their eggs. And it turns out each species of fly egg has a unique chemical fingerprint—enough to tell the eggs apart without raising the eggs to maturity. The study is in the journal Analytical Chemistry.

    Musah and her colleague Jennifer Rosati are now testing the method on a real case. “And once we do that we will be publishing some case studies to illustrate(阐明) that this is a method that can be used, and hopefully eventually it's something that will stand up in court, and something that could speed up detective work—or help deal with a cold case.”

Hear the Wind Blow by Mary Downing Hahn

    On a cold, snowy night, 13-year-old Haswell Magruder makes an important decision. A wounded Confederate soldier appears at the family's farm, and Haswell convinces his mother to take the man in. Unfortunately, this sets off a horrific chain of events that leaves their house burned to the ground and their farm in ruins. With no home left, Haswell sets out in search of his older brother, a Confederate soldier.

    Ghosts of Greenglass House by Kate Milford

    Thirteen-year-old Milo is, once again, spending the winter holidays stuck in a house full of guests who are not what they seem. There are fresh clues to uncover as friends old and new join in his search for a mysterious map. The exciting ending to the beloved book is sure to thrill both fans and newcomers.

    Marge in Charge by Isla Fisher

    Jemima and Jake Button don't know what to make of their new babysitter, Marge. When she first arrives, she's dressed like a grandma and looks very serious. But as soon as Mommy and Dad are gone, Marge lets down her hair and the adventures begin. Jemima and Jake aren't supposed to shoot apple juice out of water guns, or throw impromptu (即兴的) concerts during music class—but with Marge here, everything's gone messy!

    Max Tilt: Fire the Depths by Peter Lerangis

    When 13 year old Max Tilt finds his great-great-grandfather Jules Verne's unfinished, unpublished manuscript (手稿), The Lost Treasures, he doesn't realize that he's found the answers to all his problems. He realizes that the book holds the key to something incredibly valuable. A treasure that can save his house — and maybe his entire family.

    Elizabeth Blackwell was born in England in 1821, and moved to New York City when she was ten years old. One day she decided that she wanted to become a doctor. Thai was nearly impossible for n woman in the middle of the nineteenth century. After writing many tellers asking for admission (录取) to medical schools, she was finally accepted by a doctor in Philadelphia. She was so determined that she taught school and gave music lessons to get money for the cost of schooling.

    In 1849, after graduation from medical school. She decided to further her education in Paris. She wanted to be a surgeon (外科医生), but a serious eye problem forced her to give up the idea.

    Upon returning to the United States, she found it difficult to start her own practice because she was a woman. By 1857 Elizabeth and her sister, also n doctor, along with another woman doctor, managed to open a new hospital, the first for women and children. Besides being the first woman physician and founding her own hospital, she also set up the first medical school for women.

    Birdbrain has long been a term when laughing at somebody. The common opinion is that birds' brains are simple. But that opinion has increasingly been called into question because crows and parrots, among other birds, have shown behaviors as smart as that of chimpanzees.

    The conflict of simple brain and complex behavior has led some neuroscientists (神经学家) to create a new map of the birdbrain.

    Today, in the journal Nature Neuroscience Reviews, an international group of bird experts is showing their opinion. Nearly everything written in anatomy (解剖学) textbooks about the brains of birds is wrong, they say. The bird brain is as complex, and creative as any mammal brain, they argue, and it's time to use a more exact term that shows a new understanding of the anatomies of bird and mammal brains.

    "Names have a powerful influence on the experiments we do and the way we think," said Dr. Erich, a neuroscientist at Duke University and a leader of the Bird Brain Terms Association. "Old term has prevented scientific progress."

    The association of 29 scientists from six countries met for seven years to develop new, more exact names for structures in both bird and mammal brains. For example, the bird's seat of intelligence or its higher brain is now named the pallium (大脑皮层).

    "The change of terms is a great advance," said Dr. Jon Kaas, a leading expert in neuroanatomy at Vanderbih University. "It's hard to get scientists to agree about anything."

    Scientists have come to agree that birds are indeed smart, but those who study bird intelligence differ on how birds got that way. Experts are split into two warring camps. One holds that birds' brains make the same kinds of internal (内在的) connections as do mammal brains and that intelligence in both groups arises from these connections. The other holds that bird intelligence developed through increasing an old part of the mammal brain and using it in new ways and it questions how developed that intelligence is.

    Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play, catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins "Twinkle, twinkle, little star" or remember the story of Cinderella or Goldilocks and the Three Bears.

    One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, extra learning trials (尝试) increase the length of time we will remember it.

    In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as "Twinkle, twinkle, little star" and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

    The multiplication tables (乘法口诀表) are an exception (例外) to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.

The law of overlearning explains why cramming (突击学习) for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.

Where am I? What am I doing? If you're one of my 500 friends online, you'll always be the first to know. My phone and laptop are never out of touching distance, so I'm endlessly checking through all my social networking apps - whether I'm having a coffee, on my way to school, watching TV. . even when I'm in the shower. I have a never - ending flow of messages and updates from all the people I associate with online. Yet the truth of the matter is: I feel lonely

I'm not the only person who feels this way. According to research, over two-thirds of young people find it easier to make friends online than it is "in real life". I'm a shy person, but I'm wired up (上线) every day, like most of my friends. On the surface, phones bring us closer together. But in reality, my mind is always a million miles away.

I often feel depressed, dissatisfied and alone. Since I spend so much time socializing online, I even become a procrastinator (拖延者). I keep postponing things that are important in my real life: homework, tasks, connecting with my friends and family members in a meaningful way. It's funny that my friends and I chatter away online so much, but we end up having nothing to say when we meet.

What is rally worrying is that no one I know, including myself. could go cold turkey. I can't even imagine going without social networking for a week - think of all the important appointments, invitations and news updates you would miss! Alcoholics (酗酒者) who want to quit drinking can avoid drinks, but how do we give up our phones? After all, I need it for my studies because my teachers and classmates need to contact me at any time. So, that's the problem with social networking. We're hard-wired in, but we're more disconnected than ever.