Food picked up just a few seconds after being dropped is less likely to contain bacteria than if it is left for longer periods of time, according to the findings of research carried out at Aston University's School of Life and Health Sciences. The findings suggest there may be some scientific basis of the "5-second rule" — the belief about it being fine to eat food that has only had contact with the floor for five seconds or less. Although people have long followed the ‘5-second rule', until now it was unclear whether it actually helped.

    The study, undertaken by final year Biology students and led by Anthony Hilton, Professor of Microbiology at Aston University, monitored the transfer of the common bacteria from a variety of indoor floor types as carpet, cement floor to toast, pasta, biscuit and a sticky sweet when contact was made from 3 to 30 seconds. The results showed that: time is a significant factor in the transfer of bacteria from a floor surface to a piece of food, and the type of flooring the food has been dropped on has an effect, with bacteria least likely to transfer from carpeted surfaces and most likely to transfer from cement flooring surfaces to moist foods making contact for more than 5 seconds. Professor Hilton said, "Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time."

    The Aston team also carried out a survey of the number of people who employ the ‘five-second rule'. The survey showed that: 87% of the people surveyed said they would eat food dropped on the floor, or already have done so. 55% of those that would, or have eaten food dropped on the floor are women. 81% of the women who would eat food from the floor would follow the ‘5-second rule'. Professor Hilton added, "Our study showed that a surprisingly large majority of people are happy to consume dropped food, with women the most likely to do so. But they are also more likely to follow the ‘5-second rule, which our research has shown to be much than an old wives' tale."

    I used to be crazy about the hunting season. The excitement of waiting for a prey(猎物)and the pride of showing off the kill fascinated me. However, everything changed after that cold morning.

    Early on that day of the late fall, I set off alone for the woods, packing a gun, a bottle of hot coffee and three thick sandwiches. After finding the fresh deer's tracks in the snow, I settled down behind a little bush.

I sat there for about an hour. It was then that I saw him. A deer, a big beautiful deer! There was no cover nearer to him than 30 yards. Surely I couldn't miss! I waited for him to realize I was there. I waited for him to be shocked and run away. But he fooled me completely. He came towards me! He was curious, I suppose, or maybe lie was stupid—how else can you explain it? Well, that deer walked right up to where I was sitting. Then he stopped and looked at me!

    What happened next is hard to believe, but it's true. And it all seemed quite natural. Just as when a friendly young deer comes near you, I reached up and scratched his head. And he liked to be scratched. In fact, he practically asked for more. Then, I fed him my sandwich! Yes, I know what a deer eats, but that deer ate my sandwich. Well, he finally went his way, down the hill and up the deer trail. Shoot him? Not me. You wouldn't have either, not after that. I just watched him go.

    When I was about half way back, I heard two shots, followed by a dull slam(撞击)a few seconds later. Those two shots usually mean a kill. I had forgotten there were other hunters that day.

    Those hunters would never know they could have scratched his head.

    About one million adults in the USA need someone to help them eat. Researchers at the University of Washington are working on a robotic system that can help make it easier. After identifying different food on a plate, the robot can decide how to use a fork to pick up and deliver the desired bite to a person s mouth.

    "Being dependent on a caregiver to feed every bite every day takes away a person's sense of independence," said the researcher. "Our goal with this project is to give people a bit more control over their lives the idea was to develop a feeding system that would be attached to wheelchairs and feed people whatever they wanted to eat.

    "When we started the project, we realized there are so many ways that people can eat a piece of food depending on its size, shape or consistency(坚实度)," said the researcher, "So we set up an experiment to see how humans eat common foods. "

    The researchers arranged plates with about a dozen different kinds of food, ranging in consistency from hard carrots to soft bananas. Then the team gave volunteers a fork and asked them to pick up different pieces of food and feed them to a model. The fork contained a sensor to measure how much force people used when they picked up food.

    To design a feeding strategy that changes based on the food item, the researchers combined two different algorithms (算法). First they used an object-detection algorithm called Retina Net, which scans the plate, identifies the types of food on it and places a frame around each item. Then they developed SPNet, an algorithm that examines the type of food in a specific frame and tells the robot the best way to pick up the food.

    The team is currently working with the Taskar Center for Accessible Technology to get advice from caregivers and patients on how to improve the system to meet people's need.

    In 1973, I was teaching elementary school. Each day, 27 kids entered "The Thinking Laboratory." That was the name students voted for after deciding that "Room 104" was too dull.

    Freddy was an average student, but not an average person. He had the rare balance of fun and compassion(同情). He would laugh the loudest over fun and be the saddest over anyone's misfortune.

    Before the school year ended, I gave the kids a special gift, T-shirts with the words "Verbs Are Your friends" on them. I had advised the kids that while verbs may seem dull, most of the fun things they do throughout their lives will be verbs.

     Through the years, Pd run into former students who would provide updates on old classmates. I learned that Freddy did several jobs after his graduation from high school and remained the same caring person I met forty years before. Once, while working overnight at a store, he let a homeless man sleep in his truck. Another time, he lent a friend money to buy a house.

    Just last year, I was conducting a workshop when someone knocked at the classroom door. A woman excused the interruption and handed me an envelope. I stopped teaching and opened it up. Inside were the "Verbs" shirt and a note from Freddy's mother. "Freddy passed away on Thanksgiving. He wanted you to have this."

    I told the story to the class. As sad as it was, I couldn't help smiling. Although Freddy was taken from us, we all took something from Freddy.

    Physical education, or PE, isn't required for all high school students. In some schools, it isn't offered for some different reasons. But should high school students have physical education? The answer is certainly "yes".

    Today many people don't do sports. But as is known to all, doing sports is very important for an adult. Teaching teens the importance of a healthy lifestyle and making fitness plans now can help teens put exercise in the first place as an adult.

    High school isn't that easy. Many students are under a lot of stress. Stress can be harmful to a student's studies and life. Doing sports can help them deal with stress better, helping them live a happier life at school.

    The American Heart Association says that 10 million kids and teens suffer from obesity (肥胖症). Teens should get 60 minutes of physical activity per day to control their weight and to help their bones get stronger. The increase in activities that don't get teens to move around, such as video games and computer activities, means many teens don't get their required exercise. PE classes act as a public health measure to encourage physical activities and help teens have healthy weights.

    Not doing sports increases teens' risk of developing many diseases. An active lifestyle offers a good way of protection from these health problems. As much as 75 percent of health-care spending goes toward treating medical conditions that can be hindered by lifestyle changes, according to the American College of Sports Medicine.

    According to the President's Council on Fitness, Sports and Nutrition (PCFSN), students who performed five hours of physical activity each week improved their academic (学业的) performance. Students from programs with no physical activity, who used the extra time for classroom study, did not perform better on tests than those who gave up some study time in support of physical education.

Biologists from the John Innes Centre in England discovered that plants have a biological process which divides their amount of stored energy by the length of the night. This solves the problem of how to portion out (分配) energy reserves during the night so that the plant can keep growing, yet not risk burning off all its stored energy.

While the sun shines, plants perform photosynthesis (光合作用). In this process, the plants change sunlight, water and carbon dioxide into stored energy in the form of long chains of sugar, called starch (淀粉). At night, the plants burn this stored starch to fuel continued growth.

"The calculations are precise so that plants prevent starvation but also make the most efficient use of their food," said study co-author Alison Smith. "If the starch store is used too fast, plants will starve and stop growing during the night. If the store is used too slowly, some of it will be wasted. "

The scientists studied the plant Arabidopsis, which is regarded as a model plant for experiments. To give the plants some math tests, the biologists let night arrive unexpectedly early or late for them.

During one of the exams, they shut off the lights early on them that had been grown with twelve-hour days and nights. Putting them into darkness after only an eight-hour day means they didn't have time to store as much starch as usual. And this forced the plants to adjust their normal nightly rhythm.

Amazingly, even after this day length trick, the plants did very well in their exams and ended up with just five percent of starch left over at the end of the night. They had neither starved, nor stored starch that could have been used to fuel more growth.

The authors suggested that similar biological calculators may explain how a migratory bird, the little stint, can make a five-thousand-kilometer journey to their summer habitat in the Arctic and arrive with enough fat reserves to survive only approximately half a day more, on average.

The results of the study were published in e Life.