We've all experienced that feeling that comes when your phone makes a sound to tell you that its battery level is low. It often comes at the worst times – when you're out on a trip and don't have a charger, or when you're expecting an important phone call.

    Indeed, this feeling is so common that South Korean electronics manufacturer LG has given it a name: low battery anxiety.

    According to a survey of 2,000 US adults conducted by the company last year, 90 percent of respondents said that they panic if their battery level reaches 20 percent or lower.

    And last month, UK telecommunications service provider 02 found that around 15.5 million Britons live in “constant fear” of their mobile phones running out of power, according to a survey by the company.

    “The problem is not about being unable to make calls, but is rooted in the fact that smartphones are now where we store digital memories,” noted the Daily Mail.

    However, battery worries don't just affect smartphone lovers. Many owners of electric vehicles also suffer from so-called “range anxiety”. This refers to the concern that the vehicle may not make it to its destination before the power runs out.

    Meanwhile, it isn't just low power that people worry about. A study carried out by South Korea's Sungkyunkwan University and China's City University of Hong Kong found that many of us also worry about not having constant access to our phone.

    This condition is known as nomophobia, short for “no mobile phone phobia（恐惧症）”. Symptoms include feeling uncomfortable when access to one's phone isn't possible, being unable to turn off your phone, and constantly topping up the battery to make sure it never dies.

    So, why do so many people treat their smartphone with such importance? The underlying reason may be that they keep us connected to the people around us, and if we're unable to use our phone, we feel like we're cut off from our social life.

    With products with bigger batteries being released all the time though - such as Xiaomi's Mi Max smartphone range or Tesla's Model S cars – battery anxiety may hopefully soon be a thing of the past.

    With only about 1,000 pandas left in the world, China is desperately trying to clone the animal and save the endangered species. That's a move similar to what Texas A & M University researchers have been undertaking for the past five years in a project called "Noah's Ark".

    Noah's Ark is aimed at collecting eggs, embryos (胚胎), semen and DNA of endangered animals and storing them in liquid nitrogen. If certain species should become extinct, Dr. Duane Kraemer, a professor in Texas A & M's College of Veterinary Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.

    It is estimated that as many as 2,000 species of mammals, birds, reptiles will become extinct in over 100 years. The panda, native only to China, is in danger of becoming extinct in the next 25 years.

    This week, Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit. They are now trying to implant the embryo into a host animal. The entire procedure could take from three to five years to complete.

    "The nuclear transfer (核子移植) of one species to another is not easy, and the lack of available panda eggs could be a major problem," Kraemer believes. "They will probably have to do several hundred transfers to result in one pregnancy. It takes a long time and it's difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort," adds Kraemer, who is one of the leaders of the Project at Texas A & M, the first-ever attempt at cloning a dog.

    "They are trying to do something that's never been done, and this is very similar to our work in Noah's Ark. We're both trying to save animals that face extinction. I certainly appreciate their effort and there's a lot we can learn from what they are attempting to do. It's a research that is very much needed."

    A T-shirt that constantly monitors the heart's activity and detects abnormalities could help protect people against stroke. The T-shirt, which can be washed up to 35 times before it needs replacing, has been developed to improve the detection of dangerous heart conditions like atrial fibrillation( 心房颤动), which causes an irregular heart rhythm and raises the risk of stroke.

    At least one million people in Britain are known to have this condition; however, it's estimated that at least another 500,000 have it but haven't yet been diagnosed because they have no obvious symptoms. Some will have symptoms such as chest pain, dizziness and fatigue; but a large number of people have no idea they're ill until they suffer a stroke.

    Detecting atrial fibrillation involves carrying out an ECG(心电图). Conventional ECGs are done in a hospital and involve highly trained teams of staff attaching up to 24 separate electrodes(电极) to different parts of the body to measure electrical signals. But most patients experience abnormal rhythms only intermittently(间歇地). This means the chance of picking them up during a short hospital check is slim.

    Doctors sometimes issue patients with a device called a Holter monitor to wear under their clothes to try to pick up cardiac( 心脏的) problems. This is an electronic box which clips onto your waistband and is connected to a series of electrodes worn on the upper part of your body. But the box itself is quite bulky, hard to hide beneath clothing and involves a dozen or more wires being attached to the patient's chest.

    The Cardioskin T-shirt, which is made from cotton, could be a much more convenient alternative and can be worn 24 hours a day — meaning it is more likely to pick up any abnormal rhythms in the patient's heart. It has 15 tiny electrodes woven into the material which are strategically placed around the chest area to track the electrical signals from the heart as they travel across the main part of your body.

    The electrodes are powered by a battery which can be removed easily when you need to wash the T- shirt and feed results to a microchip which then sends them out wirelessly to an app. This converts( 转换) the data into an easy-to-read chart showing if the heart rate is abnormal. The results are shared with the patient's doctor so they can check the patient's heart without having to call them into the hospital.

    Martin Cowie, a professor of cardiology at Imperial College London, said, “Cardioskin could be an important development for cardiologists.”

    Three men traveling on a train began a conversation about the world's greatest wonders.

    "In my opinion, "the first man said, "the Egyptian pyramids are the world's greatest wonder. Although they were built thousands of years ago, they are still standing. And remember: the people who built them had only simple tools. They did not have the kind of machinery that builders and engineers have today."

    "I agree that the pyramids in Egypt are wonderful," the second man said, "but I do not think they are the greatest wonder. I believe computers are more wonderful than the pyramids. They have taken people to the moon and brought them back safely. In seconds, they carry out mathematical calculations that would take a person a hundred years to do."

    He turned to the third man and asked, "What do you think is the greatest wonder in the world?"

    The third man thought for a long time, and then he said, "Well, I agree that the pyramids are wonderful, and I agree that computers are wonderful, too. However, in my opinion, the most wonderful thing in the world is this thermos."

    And he took a thermos out of his bag and held it up.

    The other two men were very surprised. "A thermos?" they exclaimed. "But that's a simple thing."

    "Oh, no, it's not," the third man said. "In the winter you put in a hot drink and it stays hot. In the summer you put in a cold drink and it stays cold. How does the thermos know whether it's winter or summer?"

Young Adult Groups

    ●Around the World in 80 Books — 9,186 members

    If you love exploring the world through books, you have come to the right place! It all started as a challenge on TNBBC in 2009, and now we have our own group! Challenge participation is not a requirement of joining. Anyone who loves reading books is welcome.

    Website: http: //www.worldinbooks.com

    Rules: Respect each other's opinions and have fun!

    ●Readers That Love Giveaways — 734 members

    This group is for readers that enjoy entering give-aways and finding freebies(免费物)! Follow us for the newestbargain, discounted, and free e-books, as well as new releases and book recommendations. Website: http://www.fireandicebooktours.com

    Rules: Please share your items in the appropriate folders!

    ●Book Loving Kiwis — 706 members

    A group for New Zealand book lovers（and authors）and lovers of New Zealand books（and books in general）. Aplace to share what we're reading, introduce books we have written, and discuss and recommend books. Please recommend us to your friends.

    Website: http://www.kiwisbook.com

    Rules: Enjoy reading! Respect all group members and their opinions.

    ●A Book and a Cappucino — 77 members

    This group is for anyone who likes to read and likes to read at their own pace. It does not matter how much or how little you read. It's just a friendly place to discuss what you're reading and to get ideas for your next read. You can participate as much or as little as you like.

    Website: http://www.bookandcappucino.com

    Rules: Be respectful to all. Everyone has a right to share opinions.