Now satellites are helping to forecast the weather.They are in space，and they can reach any part of the world.The satellites take pictures of the atmosphere (大气)， because this is where the weather forms.They send these pictures to the weather stations.So meteorologists (气象学家) can see the weather of any part of the world.From the pictures，the scientists can often say how the weather will change.

Today，nearly five hundred weather stations in sixty countries receive satellite pictures.When they receive new pictures， the meteorologists compare them with earlier ones.Perhaps they may find that the clouds have changed during the last few hours.This may mean that the weather on the ground may soon change，too.In their next weather forecast，the meteorologists can say this.

So the weather satellites are of great help to the meteorologists.Before satellites were invented， the scientists could forecast the weather for about 24 or 48 hours.Now they can make good forecasts for three or five days.Soon，perhaps，they may be able to forecast the weather for a week or more ahead.

Why Do Mockingbirds Copy?

Mockingbirds live in North and South America. They are good copycats. They imitate other birds. But they can also imitate other animals. They can even make sounds like a piano or car alarm. Mockingbirds learn to sing many songs. Some learn more than 200 different songs. They can often trick people! But mockingbirds can't trick other birds. If they can't trick other birds, why do they copy sounds? They do it to attract and avoid other birds!

Males are loud singers, and they sing many songs. They always sing when they want to meet females. A male bird can sing most of the day and night. The singing attracts females. But it also keeps away other males. The longer a mockingbird lives, the more songs it knows. To show this characteristic, the male mockingbird sings all the songs it knows. A female mockingbird is attracted to a male who has lived a long time.

Mockingbirds usually sing short songs. They sing each sound several times. Then they move to the next sound. Female mockingbirds sing softly and less often than males. They usually sing at their nests in the winter to keep away other birds. When another bird comes near, the mockingbird makes a loud noise to frighten it. It's amazing that the mockingbird can copy so many songs of other birds. Some songs are not easy to learn.   The mockingbird must listen well to imitate the sounds. But a mockingbird also has good eyes and a good memory. When a person comes near its nest, the mockingbird remembers that person. It knows that person's face after many years!

A Finnish study coordinated by the Centre for Population Health Research at the University of Turku shows that accumulated adverse (不利的) psychosocial factors in childhood are associated with worse midlife learning and memory, and specifically child’s self-regulation and social adjustment.

Along with aging population, the problem of cognitive deficits (缺陷) is growing. Thus, revealing the role of various exposures beginning from childhood is important in order to bring tools for cognitive health promotion. An adverse psychosocial environment in childhood may harm cognitive development, but the associations for adulthood cognitive function remain obscure. Results from a longitudinal (纵向的) Finnish study show that unfavorable childhood psychosocial factors may be linked to poorer learning and memory in midlife.

“Previous evidence on adverse psychosocial factors and cognitive outcomes comes from short-term studies focusing on single psychosocial factor or adversity. This study is a prospective longitudinal study focusing on the associations between multiple childhood psychosocial factors and adulthood cognitive function,” says Doctoral Researcher Amanda Nurmi from the Centre for Population Health Research at the University of Turku and Turku University Hospital.

Cognitive performance was measured at the age of 34-49. Of over 2,000 participants with cognitive function data, 1,191 also had complete data on childhood psychosocial factors. Socioeconomic and emotional environment, parental health behaviours, stressful events, self-regulation, and social adjustment were questioned in the baseline. The results suggest that accumulation of unfavorable psychosocial factors in childhood may associate with poorer cognitive function in midlife. Specifically, poor self-regulatory behavior and social adjustment in childhood are associated with poorer learning ability and memory approximately 30 years later.

“The results of our study can be employed to develop targeted interventions directed towards those families with accumulated negative psychosocial factors. Interventions towards promoting a better psychosocial environment in childhood might have carry-over associations on cognitive function and thus be reflected also in future generations through parenting attitudes,” Nurmi says.