English news for Wednesday, September 16, 2026

Many animals, including people, have a body clock^*1 in the brain. This clock makes the rhythm^*2 of sleeping and waking up. The correct rhythm is about 24 hours, the same as one turn of the Earth. But until now, scientists had not clearly shown in experiments^*3 that this 24-hour rhythm is really important for staying alive.

Now a research group at Okayama University, a university in western Japan, has shown it. The group includes Sae Aikawa, a graduate student^*4, Professor Taishi Yoshii, who studies body clocks, and Professor Makiko Mimura, who studies ecology^*5. Their study was published^*6 in iScience, an American science magazine, on August 10, 2026.

The scientists used fruit flies^*7. Fruit flies are useful because scientists can change their genes^*8 easily. The group made "abnormal^*9" flies. In these flies, only the body clock in the brain was broken. Then they kept the abnormal flies and normal flies together for many generations^*10. The flies had to compete^*11 to survive^*12.

The result was clear. Flies with the correct rhythm had a very big advantage^*13 over flies with a broken rhythm. Flies with an 18-hour "day" became fewer and fewer over the generations. The study shows strictly that the correct rhythm is important for survival^*14.

The study may be important for people, too. Human body clocks are different from person to person. Some people are "morning people" and some are "night people." When a person's own rhythm does not match the time of school or work, this mismatch^*15 may have bad effects on the body and on daily life that we cannot see.

1. *1 body clock: a system inside the body that tells it when to sleep and when to wake up
2. *2 rhythm: a pattern that repeats again and again at the same times
3. *3 experiments: tests that scientists do to find out if something is true
4. *4 graduate student: a student who has finished university and is studying more to become a scientist
5. *5 ecology: the study of how living things live together in nature
6. *6 published: printed or put out so that people can read it
7. *7 fruit flies: very small flies that scientists often use in studies
8. *8 genes: the parts inside a living thing that carry information from parents to children
9. *9 abnormal: not normal; different from the usual way
10. *10 generations: the parents, then their children, then their children's children, and so on
11. *11 compete: to try to win against others
12. *12 survive: to stay alive
13. *13 advantage: something that helps you do better than others
14. *14 survival: staying alive
15. *15 mismatch: when two things do not fit together well

Scientists in Japan have found a new way to check the health of a forest. They count small beetles that fly into a special trap^*1. The study was published online on September 6, 2026, in the science journal^*2 Forest Ecology and Management.

People cut trees for wood, but they also want to protect the many kinds of living things in the forest. To do both, scientists need a way to measure how animals and plants react when trees are cut.

The research group, led by Minori Tokito, an assistant professor^*3 of agriculture, studied ruri stag beetles^*4. These beetles live in forests of broad-leaved^*5 trees. The young beetles grow inside old, rotten wood, and the adult beetles eat new buds^*6 high in the trees. Because of this, scientists think the beetles can show how good a broad-leaved forest is for living things.

In the past, counting these beetles was difficult. The results depended on how skilled the person was, and searching for the beetles often destroyed the places where they lay their eggs.

In 2021, the group proposed a new trap called F-FIT, or a "honey trap." A female beetle sits inside the trap. Male beetles fly toward her, hit a board, and fall into the trap. In this way, scientists can count how many beetles are caught in a set amount of time and compare the numbers.

In this study, the group placed many of these traps in a forest in Hida, a city in Gifu Prefecture in Japan. In this forest, people cut broad-leaved trees for wood. The scientists recorded where each trap was and studied the numbers together with the locations.

They found that more beetles were caught deeper inside the forest. They also found that the link between the number of beetles and how close together the trees grow may be different from place to place.

The scientists say it is not enough to think only about how each part of the forest is cut and cared for. When people take wood out of a forest, they use machines, places to pile up logs^*7, and roads to carry the logs. These make open spaces in the forest for a time. The scientists say it is important to think about these open spaces and where they are in relation to the forest that is left around them.

The group hopes to test the method in larger areas next. They also hope that people who take care of forests will start to use it.

1. *1 trap: A thing made to catch animals.
2. *2 journal: A magazine where scientists print their studies.
3. *3 assistant professor: A teacher and scientist at a university.
4. *4 ruri stag beetles: Small beetles with a shiny blue or green color. They live in Japanese forests.
5. *5 broad-leaved: Trees with wide, flat leaves, not needles.
6. *6 buds: New leaves or flowers when they are still small and closed.
7. *7 logs: Long pieces of tree trunk after the tree is cut.

Hachioji, a city in Tokyo, the capital of Japan, said on Wednesday, September 16 that a bear was seen on Mt. Takao. The bear was an Asian black bear^*1. It was seen in the mountains near Trail No. 1 in the Takao area of the city.

The bear was seen at about 11 p.m. on Thursday, August 20. The Tokyo government told the city about it on September 16. So far, no tracks^*2 or other signs of the bear have been found.

The city has a plan for bears. Under this plan, the city has set the danger level at level 1. This means the city will watch the area.

The city also warned people who climb the mountain. Many visitors will come during Silver Week, a holiday time in Japan, and in the season when the leaves turn red and yellow.

The city asks people not to go into the mountains early in the morning, in the evening, or at night. People should not walk alone. They should carry a bell or a radio to make noise. If they see a bear, they should not disturb^*3 it. They should move away quietly.

The city will keep watching the area.

1. *1 Asian black bear: a kind of black bear that lives in Japan and other parts of Asia
2. *2 tracks: marks that an animal's feet leave on the ground
3. *3 disturb: to bother or make something afraid or angry