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    While residents of wealthy nations tend to have greater life satisfaction, new research shows that those living in poorer nations report having greater meaning in life.

    These findings, published in Psychological Science, a journal of the Association for Psychological science, suggest that meaning in life may be higher in poorer nations as a result of greater religiosity (笃信宗教). As countries become richer, religion becomes less central to people's lives and they lose a sense of meaning in life.

    “Thus far, the wealth of nations has been almost always associated with longevity, health, happiness or life satisfaction,” explains psychological scientist Shigehiro Oishi of the University of Virginia. “Given that meaning in life is an important aspect of overall well-being, we wanted to look more carefully at differential patterns, correlates (相关物), and predictors for meaning in life.”

    Oishi and colleague Ed Diener of the University of Illinois at Urbana-Champaign investigated life satisfaction, meaning, and well-being by examining data from the 2007 Gallup World Poll, a large-scale survey of over 140,000 participants from 132 countries. In addition to answering a basic life satisfaction question, participants were asked: “Do you feel your life has an important purpose or meaning?” and “Is religion an important part of your daily life?”

    The data revealed some unexpected trends: “Among Americans, those who are high in life satisfaction are also high in meaning in life,” says Oishi. “But when we looked at the societal level of analysis, we found a completely different pattern of the association between meaning in life and life satisfaction.”

    When looking across many countries, Oishi and Diener found that people in wealthier nations were more educated, had fewer children, and expressed more individualistic attitudes compared to those in poorer countries — all factors that were associated with higher life satisfaction but a significantly lower sense of meaning in life.”

    The data suggest that religiosity may play an important role: Residents of wealthier nations, where religiosity is lower, reported less meaning in life and had higher suicide rates than poorer countries.

    According to the researchers, religion may provide meaning to life to the extent that it helps people to overcome personal difficulty and cope with the struggles of working to survive in poor economic conditions:

    “Religion gives a system that connects daily experiences with the coherent whole (连贯的整体) and a general structure to one's life … and plays a critical role in constructing meaning out of extreme hardship,” the researchers write.

    Oishi and Diener hope to reproduce these findings using more comprehensive measures of meaning and religiosity, and are interested in following countries over time to track whether economic prosperity gives rise to less religiosity and less meaning in life.

    An international team of researchers from the University of Oxford have found that the way people use the Internet is closely tied to the seasonal movements in the natural world. Their online species searches follow the patterns of seasonal animal migrations (迁徙).

    Migratory birds (候鸟) flood back to where they reproduce every spring. That migratory behavior is accompanied by some human behavior. "In English-language Wikipedia (维基百科), the online searches for migratory species tend to increase in spring when those birds arrive in the United States," said the lead author John Mittermeier.

    And not just birds. Mittermeier and his team surveyed nearly 2.5 billion Wikipedia search records, for 32,000 species, across 245 languages. They also saw variable search rates for insects, horsetails and flowering plants. Seasonal trends seemed to be widespread in Wikipedia behavior for many species of plants and animals.

    This finding suggests new ways to monitor changes in the world's biological diversity. It also shows new ways to see how much people care about nature, and which species and areas might be the most effective targets for conservation.

    Mittermeier is encouraged by the search results. He commented, "I think there's a concern among conservationists (生态环境保护者) that people are losing touch with the natural world and that they're not interacting with native species anymore. And so in that sense, it was really exciting and quite unexpected for me to see people's Wikipedia interest closely related to changes in nature."

    Richard Grenyer, Associate Professor from the University of Oxford, says search data is useful to conservation biologists, "By using these big data approaches, we can direct our attention towards the difficult questions in modern conservation: which species and areas are changing, and where are the people who care the most and can do the most to help."

    A smile will tell people around you that you are a kind and friendly person. However, many people don't smile because they think they have ugly teeth. For example, one of my classmates, Mike, doesn't have very nice teeth, so that is why he seldom opens his mouth. He even says that he has lost confidence because of his teeth. So it is very important for us to look after our teeth. In fact, a lot of people have this problem. Some people inherit tooth problems from their parents, while others' teeth are damaged because of bad habits, like heavy smoking, eating too much sugar or not brushing teeth often. If your teeth are in bad shape, you should see a dentist and ask for help. They can help improve your teeth and tell you how to take care of them.

    Smiling can help you feel more confident and make people think of you as a more friendly person. If you want to keep healthy, you should not only smile but also laugh. An Indian doctor called Kataria said that young children should laugh about 30 times a day, while adults should laugh between 7 and 15 times a day. So please take this chance to smile and laugh now.

    Rivers are earthly arteries(要道) for the nutrients, deposits and freshwater that sustain healthy, diverse ecosystems. Their influence extends in multiple dimensions—not only along their length but below­ground to aquifers(蓄水层) and periodically into nearby floodplains.

    They also provide vital services for people by fertilizing agricultural land and feeding key fisheries and by acting as transportation corridors. But in efforts to ease ship passage, protect communities from flooding, and draw off water for drinking and irrigation, humans have increasingly constrained and broken these crucial water ways. “We try to control rivers as much as possible,” says Gunther Grill, a hydrologist at McGill University.

    In new research published in May in Nature, Grill and his colleagues analyzed the barriers to 12 million total kilometers of rivers around the world. The team developed an index(指数) that evaluates six aspects of connectivity—from physical fragmentation (by dams, for example) to flow regulation (by dams or levees) to water consumption—along a river's various dimension. Rivers whose indexes meet a certain threshold(临界值) for being largely able to follow their natural patterns were considered free­flowing.

    The researchers found that among rivers longer than 1,000 kilometers (which tend to be some of those most important to human activities), only 37 percent are not blocked along their entire lengths. Most of them are in areas with a minimal human presence, including the Amazon and Congo basins and the Arctic. On the contrary, most rivers shorter than 100 kilometers appeared to flow freely—but the data on them are less comprehensive, and some barriers might have been missed. Only 23 percent of the subset of the longest rivers that connect to the ocean are uninterrupted. For the rest, human infrastructure is starving estuaries(河口) and deltas (such as the Mississippi Delta) of key nutrients. The world's estimated 2.8 million dams are the main cause, controlling water flow and trapping deposits.

    The new research could be used to better understand how proposed dams, levees and other such projects might impact river connectivity, as well as where to remove these fixtures to best restore natural flow. It could also help inform our approach to rivers as the climate changes, says Anne Jefferson, a hydrologist at Kent State University, who was not involved in the work. Existing infrastructure, she says, “has essentially been built to a past climate that we are not in anymore and are increasingly moving away from.”

After a decade of negotiations, nearly 200 countries have agreed to a new United Nations treaty（条约）to protect the world's oceans, the first of its kind in 40 years. The High Seas Treaty aims to protect 30% of the open oceans by 2030, setting a plan in motion to preserve this vast area.

Oceans cover about 71% of the Earth's surface and are home to countless species of animals and plants. They play a crucial role in maintaining a healthy planet. However, overfishing and pollution from ships and other sources have severely impinged on many marine （海洋的）species and ecosystems.

The last major UN sea treaty in 1982 described the "high seas"—the parts of the oceans that aren't controlled by any country—but it did not protect them. The high seas, which account for two-thirds of the ocean, currently have only 1. 2% of their massive area protected. A marine protected area（MPA）is an area in the sea with strict rules about fishing and other activities. While more and more countries have established MPAs in their waters, most are not connected, limiting their effectiveness for migratory（迁徙的）species.

Last December, over 110 countries committed to protecting 30% of their land and ocean areas by 2030. The High Seas Treaty now enables the extension of this goal to the entire ocean. It aims to make 30% of the high seas become protected areas by 2030 and requires that proposed activities on the high seas undergo assessment for their potential impact on the ocean environment.

Reaching the agreement was challenging due to differing views on ocean protection among countries, such as limits on fishing or pollution. Disagreements also arose over sharing resources between rich and poor nations, with the latter seeking an assurance that resources benefit everyone, not just those in wealthy countries.

The treaty is not yet final and must be officially accepted at a UN meeting. Then it must be approved and signed by enough countries before it takes effect.