【推荐1】Few things are more satisfying than sleeping in on weekends. Though the extra sleep may improve your mood, it doesn’t appear to improve your health.

Because a new study shows that so-called “recovery sleep” cannot reset the body’s metabolic clock and may actually lead to some serious problems.

“Sleep loss can impact our body’ s systems. It can increase our risk of heart disease and cause weight gain,” says Christopher Depner, an assistant professor at the University of Colorado, Boulder.

“A lot of us turn off the alarm on Saturdays and Sundays. But we go right back to burning the candle at both ends once the workweek begins. So we are really interested in how the sort of cycle of insufficient sleep, weekend recovery sleep, insufficient sleep, can impact your risk of metabolic disease.” says Depner. He and his colleagues invited volunteers to a nine-day snooze- a-thon.

One group was allowed to get a full night’s sleep. The next was kept to just five hours every night. And the third group was restricted to five hours of shut-eye during the workweek, allowed as much sleep as they wanted over the weekend, and then back to five hours for the last couple of days.

“The study shows that when volunteers maintained insufficient short sleep schedules during a normal work or school week, they ate more than they needed and this led to weight gain. And when they were eating more, they actually ate more after-dinner snacks,” says Ken Wright, a professor at U. C. Boulder.

But even more surprisingly, sleeping in on the weekend doesn’t help-and even makes things worse.

“After the weekend, when they went back to getting insufficient sleep during the work or school week, we found that their blood sugar regulation was reduced. And this is not something we had found in people who maintained insufficient sleep schedules. So it’s possible that this is a worsening of the body’s ability to regulate blood sugar for those specific tissues after the weekend.” says Wright.

So make a date with a pillow. And trade the sweets for sweet dreams.

【推荐3】Cleaning your teeth often, every day, is linked to a lower risk for heart problems. A new study found that brushing your teeth several times a day resulted in fewer cases of heart failure and atrial fibrillation, the term for an uneven heartbeat.

What the research found is that brushing your teeth three times a day, or more, was linked to a ten percent lower risk of atrial fibrillation (心房纤颤). It was also linked to a twelve percent lower risk of heart failure. The study was published last Monday in the European Journal.

The researchers examined information on more than 161,000 people in Korea with no history of heart problems. They followed up ten and a half years later, and found that three percent had developed uneven heart rhythms and almost five percent had developed heart failure. All the participants in the study were part of the Korean National Health Insurance System, and aged 40 to 79. They had usual medical exams between 2003 and 2004. Information was collected on their height, weight, laboratory tests, sicknesses, and lifestyle. They also noted their mouth health inconnection with cleaning.

You may wonder, how are teeth health and heart health connected? Earlier research suggests that not taking care to clean and brush teeth leads to bacteria in the blood. This can cause inflammation (炎症), and increases the risk for unusual heartbeat and heart failure.

A study last year by the American Heart Association showed that brushing your teeth twice a day for at least two minutes may lower the risk of cardiovascular, or heart diseases. The American Dental Association agrees. The organization said “this study is interesting, and while it may suggest an association between tooth brushing and heart health, it does not show a direct connection.”

To have good oral health, the ADA advises people to:

·Brush their teeth twice a day for two minutes each time with a fluoride (氯化物) toothpaste.

·Clean between their teeth once per day.

· Maintain a healthy diet.

·See a dentist regularly.

【推荐1】Charles Darwin, famous for his theory of evolution(进化)by natural selection, was a well-known biologist.

The Cambridge University Library in the UK contains a huge collection of Darwin’s documents that includes a pair of small notebooks known as the Tree of Life notebooks. They went missing over two decades ago, but a nameless person returned them to the library recently—wrapped in plastic and placed inside a pink gift bag. The notebooks reappeared with a simple printed message—“Librarian. Happy Easter. X.”

The notebooks got their nickname from Darwin’s 1837 hand-drawn sketch(草图)of his Tree of Life concept, which shows a branching tree as a metaphor for his ideas around evolution. The sketch is both simple and significant. ”They may be tiny, just the size of postcards, but the notebooks’ impact on the history of science, and their importance to our world-class collections here, cannot be ignored,“ says librarian Jessica Gardner.

The notebooks suffered a lot after they were removed from a secure room in 2000 so they could be photographed. The photography project was completed, but a routine check in early 2001 found the notebooks weren’t where they were supposed to be.

At first, the librarians thought the notebooks had simply been misplaced, but a series of searches over the years turned up nothing. A new search in 2020 included a deep dive into the boxes in the Darwin collection. ”However, this failed to locate the notebooks, leading to the conclusion that they had likely been stolen," the library says. In 2020, the library issued a public appeal for the return of the notebooks, which seems to have paid off.

To celebrate the notebooks’ return, the library displayed them in July in a free exhibition called Darwin in Conversation. We may never know where the notebooks spent their time away, but they should be back for good.

【推荐2】In a tiny, lab-grown garden, the first seeds ever sown in lunar dirt have come up. This small crop, planted in samples (样本) returned by Apollo tasks, offers hope that astronauts could someday grow their own food on the moon.

But plants planted in lunar dirt grew more slowly and were thinner than others grown in volcanic(火山的) material from Earth, researchers report 12 May in Communications Biology. That finding suggests that farming on the moon would take a lot more than a gardening skills.

“Ah! It’s so cool!” says a botanist (植物学家) Richard Barker. “Ever since these samples came, back, there’s been botanists that wanted to know what would happen if you grew plants in them,” says Barker, who wasn’t involved in the study. “But everyone knows those precious samples are priceless, and so you can understand why NASA was unwilling to publish them.”

The team planted seeds in tiny pots that each held about a gram of dirt. Four pots were filled with samples returned by Apollo 11, another four with Apollo 12 samples and a final four with dirt from Apollo 17. Another 16 pots were filled with earthly volcanic material used in past experiments to copy moon dirt. All were grown under LED lights in the lab and watered with nutrients.

“Nothing really compared to when we first saw the seedlings as they were coming up in the lunar dirt,” says Anna-Lisa Paul, a plant biologist. “That was a moving experience. We could not speak when we watched the very first plants growing in unique materials.”

Plants grew in all the pots of lunar dirt, but none grew as well as those planted in earthly material. “The healthiest ones were just smaller,” Paul says. The moon-grown plants were tiny. Faced with that, explorers need to do more research to let plants grow strongly on the moon. I believe we will succeed in time.

【推荐3】Taste in music varies considerably, but whatever people enjoy listening to, they often report an emotional response that has a touch of the physical to it. Maybe you feel beautiful music gives you the feeling of being cold, or makes your hair stand on end.

By studying a rare person, named BW, who does not like or respond to music at all, psychologist Psyche Loui of Northeastern University has discovered that connectivity patterns in the brain link finding music rewarding with finding social interaction enjoyable.

“BW said he had never understood why people enjoy music,” Loui says. BW is not someone who doesn’t like art, Loui says. “He goes to museums. He’s an enthusiastic photographer. He likes good food. He likes long walks on the beach. He just doesn’t like music.” He told Loui that when he saw a person at the grocery store with headphones in their ears dancing to music, he could never understand why anyone would do that. “This really seems to be a somewhat socially weakening experience,” Loui says.

“Given that music is important for social bonding across different cultures and that music is a way for the hearing system to connect to the reward system, one strong prediction is that music reward sensitivity can partially explain individual differences in sensitivity to social reward.”

This newly discovered connectivity between the hearing and reward systems may be why we feel emotions in response to music, Loui says. “I think that there’s a role of music for social bonding.” She also thinks there are influences from this work for other conditions with low social reward. “If people who don’t love music have differences in specific systems in the brain, then that shows these specific systems are related to the love of music. Then we can examine what else engages these same systems and what other abilities or human capacities are linked to music.”

【推荐1】We all love gardens with beautiful flowers and leafy plants, choosing colourful species to plant in and around our homes. Plant scientists, however, may have fallen for the same trick in what they choose to research.

The research, published in Nature Plants, found there’s a clear bias (偏好) among scientists toward visually striking plants. This means they’re more likely chosen for scientific study and conservation efforts, regardless of their ecological or evolutionary significance. White, red and pink flowers were more likely to feature in research literature than those with dull, or green and brown flowers. Plants with tall stems also stood out. Plants with blue flowers — the rarest colour in nature — received most research attention. But interestingly, a plant’s rarity didn’t significantly influence research attention. The team had expected to find more endangered species among those most studied, it did not either.

This bias may direct conservation efforts away from less visually pleasing plants that are more important to the health of the overall ecosystem or in need of urgent conservation. A bias toward colorful plants could mean we may be missing species that could be in rapid decline toward extinction, and we don’t have even basic information on seed banking for conservation. This is not a tragedy, but something to consider when planning future work.

We often don’t know how important a species is until it’s thoroughly researched. In Australia, for example, milkweeds are an important food source for butterflies, while dull-flowered mat rushes are now known to be the home for rare native sun moths. From habitats to food, these plants provide foundational ecological services, yet many milkweed and mat rush species are rare, and largely neglected in conservation research.

The study shows the need to take biases into consideration in science and in the choice of species studied, for the best conservation and ecological outcomes. People should be more alert in all parts of the conservation process, from the science to listing species for protection.