Exercise may help to safeguard the mind against depression(沮丧) through previously unknown effects on working muscles, according to a new study involving mice.

    Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can reduce someone's risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

    We can't ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it's available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed.

    The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected（怀疑） that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant（抵抗的）. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers' muscle cells contained substantially more PGC-1alpha than at the study's start.

    The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

    Whether in the home or the workplace, social robots are going to become more common in the next few years. Social robots are about to bring technology to the everyday world in a more humanized way, said Cynthia Breazeal, chief scientist at the robot company Jibo.

    While household robots today do the normal housework, social robots will be much more like partners than tools. For example, these robots will be able to tell when someone is happy or sad. This allows them to respond more properly to the user.

    The Jibo robot, arranged to ship later this year, is designed to be a personalized assistant. You can talk to the robot, ask it questions, and make requests for it to perform different tasks. The robot doesn't just give general answers to questions; it responds based on what it learns about each person in the household. It can do things such as reminding an elderly family member to take medicine or taking family photos.

    Social robots are not just finding their way into the home. They have potential(潜在的) applications in everything from education to health care and are already finding their way into some of these areas.

    Fellow Robots is one company bringing social robots to the market. The company's “Oshbot” robot is built to assist customers in a store, which can help the customers find items and help guide them to the product's location in the store. It can also speak different languages and make recommendations for different items based on what the customer is shopping for.

    The more interaction the robot has with humans, the more it learns. But Oshbot, like other social robots, is not aimed to replace workers, but to work together with other employees. “We have technologies to train social robots to do things not for us, but with us,” said Breazeal.

    Get ready to fill your days full of fun and adventure. West Dorset, an area of outstanding natural beauty, is always a place to go and there is always something going on. The following are some of the star attractions.

    Mapperton House & Gardens

    Impressive valley gardens surrounded by wooded landscape.

    Gardens open: Daily 11 am -5 pm except Fridays, March to October included.

    Booking through Tel: (0103)959203 or www.mapperton.com

    Bridport Museum

    Local history museum attracts every history lovers. We also have a year-round Local History Centre nearby where you can complete local and family history research.

    Open: Monday-Saturday, April to October included.

    Booking through Tel: (0103) 959711 or www.bridportmuseum.com

    Furlelgh Estate Wine Tours

    Vineyard and winery, producers of the UK's most outstanding wine. Come and see how the 2019 Winemaker of the Year makes wine.

    Open for sales: 11 am-4 pm Fridays and Saturdays, tours at 2 pm.

    Booking through Tel: (0103) 906323 or wwwjurleiehestate.uk

    Old Crown Court and Cells

    Experience two hundred years of shocking crime and punishment. Tours of court room and cells on selected afternoons mid July to end August.

    Open: Tuesday-Sunday, March to September included.

    Booking through www.visitdorset.com

    For all the latest information about attractions including opening times, reasonable prices and special offers，please go to www.visitdorset.com

    As people age, the body changes in all sorts of predictable ways. Brains can slow. Wounds take longer to recover. And sleep patterns(模式) shift, too. This can come as news to many, says Michael V. Vitiello, a psychologist at the University of Washington who is expert in sleep in aging.

The most noticeable—and often most annoying—changes are how sleep and wake-up times change and sleep gets lighter, often beginning in middle age. Gone are weekend sleep to 11 a.m. and the ability to sleep through a noisy garbage truck down the block.

But not every restless night can be ignored. Studies have found that poor sleep can create a particular threat to older adults—Falls, depression and anxiety, problems with memory, and increased suicide(自杀) risk are among the effects of sleep issues in this population group that researchers have found. But scientists are still unsure why those risk connections exist.

    What is clear is the connection between good sleep and psychological well-being in older adults. A 2010 study showed us that connection when it came to sleep quality, but sleep quantity didn't show the same effects. And that, experts say, may be the key to understanding sleep as you age. If you're sleeping less, but don't feel negative effects out of bed, the changes you notice may just be normal age-related.

    Over time, Vitiello says, sleep patterns simply change. "A lot of older adults recognize that they don't sleep the same as they did when they were 18, but they can still function and they're OK. And all is well with the universe."

    The "Give It Up for Earth Day" encourages people to commit to giving up actions that are harmful to the environment, such as using poisonous cleaners.

    Throughout the month of April, Canadians are being asked to "Give It Up for Earth Day!" Earth Day has been celebrated every year on April 22 since 1970. Earth Day Canada president Jed Goldberg says that as people become more environmentally aware, they want to find ways to reduce their environmental influence, not just celebrate one special event.

    "Earth Day is a great launching pad for thinking about environmental action every day," said Goldberg. "Choosing healthier options, even for the short term, can lead to thinking about the influence of our decisions for a lifetime."

    That's the reason behind the "Give It Up for Earth Day" campaign. It's designed to encourage healthy habits that benefit people and the planet. It challenges everyone to help create a healthier world by making changes in their daily routine.

    "We wanted to plan an action—targeted campaign that will give people a chance to act on their concern for the environment in a positive way," said Goldberg.

    The campaign has identified four daily actions that can add up to huge environmental savings. They include pledging (保证) to turn off the TV, give up the use of poisonous cleaners, reduce consumption of consumer products and cut out meat.

    At the end of April, all of the pledges will be recorded and converted (转化) into the number of TV hours not watched, dollars not spent on unnecessary items, electricity saved, greenhouse gas emissions (排放) avoided by cutting out meat, and poisonous chemicals produced from homes and landfills.

    "What we're trying to achieve this year for Earth Day is to give people a chance to do something that is meaningful and measurable," said Goldberg.

    When you live in total messiness—cookies in your pants draws, and some old New Yorkers or apple seeds in your bed—it's hard to know where to look for when you lose your keys. The other day, after two weeks of searching, I found my keys in the refrigerator. I can't say I was surprised. But I was surprised when I was diagnosed with ADHD(多动症), when I was a junior at Yale.

    According to a new study, 11% of school-age children have received an ADHD diagnosis, a 16% increase since 2007. And rising diagnoses mean rising treatments—drugs like Adderall are more accessible than ever. However, the consequences of misuse and abuse of these drugs are dangerous.

    Yet also harmful are the consequences of ADHD undiagnosed, an all-too-common story for women like me, who have symptoms, like disorganization and forgetfulness, which look different from those typically expressed in males.

    Dr. Ellen, author of Understanding Girls with ADHD, has found around 4 million females with ADHD are not diagnosed. "The main reason is that the diagnostic criteria were developed based on those hyperactive（过度活跃）young boys taken to clinics, making it difficult for girls to be diagnosed unless they behave like hyperactive boys." Ellen says.

    Besides, the idea that young women actually have ADHD often causes skepticism. As a top student, I didn't believe my diagnosis at first. My friends were also confused, and rather certain my doctor was misguided.

    "Often, if girls are smart or in supportive homes, symptoms are masked," Dr.Ellen says. "Girls will hide their inability to meet social expectations. They see their trouble organizing, and concentrating as character flaws(缺陷)."

    These years, I am both embarrassed and exhausted by my struggles to keep track of objects, but drug has helped it and made it more bearable.