Chimps live in a male-dominated society, where most of their valuable allies (同盟) are other males. However, as young male chimps become adults, they continue to maintain tight bonds with their mothers, a new study finds.

The dramatic changes of adolescence are difficult for chimps, just like they are for humans, says Elizabeth Lonsdorf, an expert on primates at Franklin& Marshall College who was not involved in the study. “Sure enough,” she adds, “their moms remain a key social partner during this time.”

Previous research has shown chimp mothers provide their sons with support that goes far beyond nursing. Young male chimps that are close with their moms grow bigger and have a greater chance of survival. What’s more, losing their mothers after weaning (断奶), but before age 12, hinders the ability of young chimps to win other males and reproduce.

To see whether this bond extends later into life, researchers followed 29 adolescent (9 to 15 years old) and young adult (16 to 20 years old) male chimps at a research site in Kibale National Park in Uganda and observed them from a distance for 3 years. The team found that the young adult males spent less time with their mothers than the adolescents did — 26% vs. 76%. As the male chimps grew older and more independent, they began to travel over wider ranges and spent more time away from their moms. And unlike the adolescents, they no longer cried for their mothers or sought comfort after fighting.

However, when these young adult males happened to be in the company of their mothers, they acted just like the adolescents. They groomed (梳理) their moms just as often and kept track of them. “Many mothers remained the males ‘best friends’, or ‘social partners’ they associated with most frequently,” says study co-leader Rachna Reddy from Harvard University.

Such persistent ties are also common in humans after sons leave their mothers and live on their own — especially in tough times, Reddy says. “We really feel what it’s like to not be able to see our mothers when we want to in tough times. The importance of those bonds in our lives and the comfort we get from them have deep evolutionary roots.”

Scientists have long sought to prevent sharp memories from dulling with age, but the problem is hard to solve. New research suggests Virtual Reality (VR) might help older people recall facts and events based on specific details.

The study involved 42 healthy older adults from the San Francisco Bay Area. Half spent a dozen hours over four weeks playing a virtual-reality game called Labyrinth. They wore headsets and walked in place, wandering virtual neighborhoods while completing missions. The other half, in the control group, used computers to play games that did not require navigationg (导航) or recalling details. After 15 sessions, the latter performed much the same as before on a long-term memory test based on picking out objects they had seen about an hour earlier. But the Labyrinth players’ scores rose, and they were less frequently tricked by objects that were similar to ones they had viewed.

“The improvement brought them back up to the level of another group of younger adults who did the same memory tests,” said cognitive neuroscientist Peter Wais of the University of California, San Francisco. He and his colleagues designed the VR game, which they say likely stimulates (刺激) the hippocampus—— a brain area that is important for long-term memory. The team did not observe improvement on two other tests, which measured autobiographical memory (自传体记忆) and spatial memory capability.

“It would be great to actually follow people over time and see what this type of game does for long-term memory,” said Meredith Thompson, a Massachusetts Institute of Technology education researcher. Daniel Simons, a cognitive psychologist, said that testing three measures, instead of just one, would increase the possibility of finding an improvement. And it remains unclear how test performance in a laboratory setting might translate to real-world situations. Simons notes, “The outcome needs to be repeated, ideally with a much larger group, before it is treated as a strong finding.”

Wais’s team is now investigating how long the observed effects last and which elements of the training have the most impact.

Airborne dust is normally seen as an environmental problem, but the lack of it is making air pollution over China considerably worse.

A new study suggests less dust means more solar radiation hits the land surface,which reduces wind speed. That lack of wind in turn leads to an accumulation of air pollution over heavily populated parts of China. The researchers found that reduced dust levels cause a 13% increase in human-made pollution in the region.

Hundreds of millions of people across China continue to be impacted by air pollution from factories and coal-fl red power plants. Studies suggest that the dirty、air contributes to 1.6 million deaths a year, about 17% of all mortalities. But this new research says that the human-induced pollution is being made worse or better by naturally occurring dust that blows in from the Gobi desert. Using models to simulate 150 years of wind and dust patterns in the region, the researchers found that the dust deflects significant amounts of sunlight. Without it, more heat from the Sun hits the land. Differences in the temperatures between land and sea cause the winds to blow. Without the dust, the land warms up more and that changes the temperature differential with the sea leading to weaker breezes - and more air pollution.

“There are two dust sources. One is the Gobi and the other is the highlands of north-west China, but we found the Gobi had much more influence," said lead author Yang Yang, from the Pacific Northwest National Laboratory in Washington State, US. “Less dust in the atmosphere causes more solar radiation to reach the surface. It weakens the temperature difference between the land and the sea and impacts the circulation of the winds and causes a stagnation over eastern- China and that causes an accumulation of air pollution.”

Another study has recently shown a link between declining Arctic sea ice and a major air pollution event in China. The authors of the new study believe that both theories could be true.

“Our study has the same mechanism: the weakening of winds causes more pollution, and what is behind this needs to be studied/ said Yang Yang, “We have two views on this kind of weakening of wind. They found the sea ice, we found the dust-wind interaction can also lead to weakening of the wind. I think both of them are important.”

The researchers believe that the study may inform broader questions about how natural human-created aerosols interact.

Many parts of the world, in addition to China, are now suffering from increased levels of air pollution and understanding how dust, winds and emissions work together may help limit some of the worst impacts of dirty air.

One of the key lessons from this study is that the absence of dusty conditions could mean the air you are breathing is worse for you, not better.