Reading can be a social activity. Think of the people who belong to book groups. They choose books to read and then meet to discuss them. Now the website BookCrossing.com turns the page on the traditional idea of a book group.

    Members go on the site and register the books they own and would like to share. BookCrossing provides an identification number to stick inside the book. Then the person leaves it in a public place, hoping that the book will have an adventure, traveling far and wide with each new reader who finds it.

    Bruce Pederson, the managing director of BookCrossing, says, “The two things that change your life are the people you meet and books you read. BookCrossing combines both.”

    Members leave books on park benches and buses, in train stations and coffee shops. Whoever finds their book will go to the site and record where they found it.

    People who find a book can also leave a journal entry describing what they thought of it. E-mails are then sent to the BookCrossers to keep them updated about where their books have been found. Bruce Peterson says the idea is for people not to be selfish by keeping a book to gather dust on a shelf at home.

    BookCrossing is part of a trend among people who want to get back to the “real” and not the virtual(虚拟). The site now has more than one million members in more than one hundred thirty-five countries.

    “The car of tomorrow” runs one of the most famous businesses in advertising. People used to believe that science would promise a future of endless spare time and very cheap electricity. Nowadays the scientists' predictions are a great deal less optimistic: a world challenged by climate change and decreasing resources.

    In fact, “the car of the future” is just a symbol of hope. Carbon emis-Investment in new technology to maximize efficiency (效率) and minimize environmental damage is not only cleaning up the automobile producers' act but is also setting an example to other industries.

    It's said that most cars of today run at about 15 per cent efficiency, which does highlight the potential (突显潜力) for improvement. Get it right, and we could continue to enjoy the freedom that comes with owning a car, without the worries.

    Of course, many advances have already been made. There's evidence that the buying public is eager to switch to cleaner, greener cars. And with petrol prices increasing there is no doubt that economical, efficient engines are going to be in ever greater demand.

    The good news is that we can all drive “the car of tomorrow” today, without having to worry about the purchase cost. By choosing our holiday hire cars wisely we can cut down on our fuel costs and experience an eco-friendly drive whether or not we have already made the commitment back home. What's more, we are caring for the beautiful places we love to holiday in. Hire a green car and you make a difference to the environment.

    Designers will always enjoy catching our imagination with “concept cars” that look more like miniature spaceships than anything you see on the highway. Whether vehicles as radical (激进的) as these creations will eventually become family cars remains to be seen. But, for the moment, there's no doubt at all what “the car of tomorrow” will be, and it's here today: something familiar and friendly that does its job with considerably less trouble and much greater efficiency than the car of yesterday.

    Why is pink or purple a color for girls and blue or brown for boys?

The answer depends largely on cultural values as well as personal experiences. To the Egyptians, green was a color that represented the hope and joy of spring, while for Muslims, it means heaven. Red is a symbol of good luck in many cultures. In China, children are given money in a red envelope to bring good fortune in the New Year. For many nations, blue is a symbol of protection and religious beliefs. Greek people often wear a blue necklace hoping to protect themselves against evils (灾祸).

    People's choice of colors is also influenced by their bodies' reactions (反应) toward them. Green is said to be the most restful color. It has the ability to reduce pain and relax people both mentally and physically. People who work in green environment have been found to have fewer stomachaches.

Red can cause a person's blood pressure to rise and increase people's appetites (食欲). Many decorators will include different shades of red in the restaurant. Similarly, many commercial (商业的)websites will have a red “Buy Now” button because red is a color that easily catches a person's eye.

    Blue is another calming color. Unlike red, blue can cause people to lose appetite. So if you want to eat less, some suggest that eating from blue plates can help.

    The next time you are deciding on what to wear or what color to decorate your room, think about the color carefully.

    Self-driving vehicles will rely on cameras, sensors and artificial intelligence (AI) to recognize and respond to road and traffic conditions, but sensing is the most effective for objects and movement in the neighborhood of the vehicle. Not everything important in a car's environment will be caught by the vehicle's camera. Another vehicle approaching at high speed on a collision (碰撞) track might not be visible until it's too late. This is why vehicle-to-vehicle communication is undergoing rapid development. Our research shows that cars will need to be able to chat and cooperate on the road, although the technical challenges are considerable.

    Applications for vehicle- to-vehicle communication range from vehicles driving together in a row, to safety messages about nearby emergency vehicles. Vehicles could alert each other to avoid collisions or share notices about passers-by and bicycles.

    From as far as several hundred meters away, vehicles could exchange messages with one another or receive information from roadside units (RSUs) about nearby incidents or dangerous road conditions through 4G network. A high level of AI seems required for such vehicles, not only to self-drive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategize and adapt in the light of information received in real time and to carry out cooperative behaviors. For example, a group of autonomous vehicles might avoid a route together because of potential risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

    Further applications of vehicle- to-vehicle communication are still being researched, including how to perform cooperative behavior.

    We've all been there: in a lift, in line at the bank or on an airplane, surrounded by people who are, like us, deeply focused on their smartphones or, worse, struggling with the uncomfortable silence.

    What's the problem? It's possible that we all have compromised conversational intelligence. It's more likely that none of us start a conversation because it's awkward and challenging, or we think it's annoying and unnecessary. But the next time you find yourself among strangers, consider that small talk is worth the trouble. Experts say it's an invaluable social practice that results in big benefits.

    Dismissing small talk as unimportant is easy, but we can't forget that deep relationships wouldn't even exist if it weren't for casual conversation. Small talk is the grease(润滑剂) for social communication, says Bernardo Carducci, director of the Shyness Research Institute at Indiana University Southeast. "Almost every great love story and each big business deal begins with small talk," he explains. "The key to successful small talk is learning how to connect with others, not just communicate with them."

    In a 2014 study, Elizabeth Dunn, associate professor of psychology at UBC, invited people on their way into a coffee shop. One group was asked to seek out an interaction with its waiter; the other, to speak only when necessary. The results showed that those who chatted with their server reported significantly higher positive feelings and a better coffee shop experience. "It's not that talking to the waiter is better than talking to your husband," says Dunn. "But interactions with peripheral(边缘的) members of our social network matter for our well-being also."

    Dunn believes that people who reach out to strangers feel a significantly greater sense of belonging, a bond with others. Carducci believes developing such a sense of belonging starts with small talk. "Small talk is the basis of good manners," he says.

    Drug companies have spent billions of dollars searching for therapies to reverse or significantly slow Alzheimer's disease, but in vain. Some researchers argue that the best way to make progress is to create better animal models for research, and several teams are now developing mice that more closely imitate how the disease destroys people's brains.

    The US National Institutes of Health (NIH), the UK Dementia Research Institute and Jackson Laboratory (JAX) - one of the world's biggest suppliers of lab mice - are among the groups trying to genetically design more suitable mice. Scientists are also exploring the complex web of mutations(突变) that influences neurological (神经学的) decline in mice and people.

    "We appreciate that the models we had were insufficient. I think it's sort of at a critical moment right now." says Bruce Lamb, a neuro-scientist at Indiana University ~ho directs the NIH-funded programme.

    Alzheimer's is marked by cognitive impairment(认知损伤) and the build-up of amyloid-protein plaques (淀粉样蛋白块) in the brains of people, but the disease does not occur naturally in mice. Scientists get around this by studying mice that have been genetically modified to produce high levels of human amyloid protein. These mice develop plaques in their brains, but they still do not display the memory problems seen in people.

    Many experimental drugs that have successfully removed plaques from mouse brains have not lessened the symptoms of Alzheimer's disease in people. One focused stumble came last month, when three companies reported that their Alzheimer's drugs had failed in large, late-stage clinical trials. Although the drugs successfully blocked the accumulation of amyloid protein in mice, they seemed to worsen cognitive decline and brain shrinkage in people.

    The drive for better mouse models comes as genomics studies are linking the most common form of Alzheimer's to dozens of different genes. This diversity suggests that each case of the disease is caused by a different combination of genetic and environmental factors. "There is no single Alzheimer's disease," says Gareth Howell, a neuro-scientist at Jackson Laboratory (JAX) in Bar Harbor, Maine.

    Howell argues that scientists' reliance on lab mice with only a few genetically engineered mutations might have limited research. His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer's develops.