Napping (小睡) may be part of life for most of us. However, some countries where daytime naps have long been part of the culture, such as Spain, now discourage the habit. Meanwhile, some companies in the US now promote napping as a way to boost productivity. “It’s important to try to reveal the biological pathways that contribute to the reason why we nap,” says Dashti from Harvard Medical School.
Previously, co-senior author Richa Sexena at Massachusett s General Hospital (MGH) and his colleagues used many databases of genetic and lifestyle information to study other aspects of sleep. To gain a better understanding of the genetics of napping, they performed a genome (基因组)-wide association study (GWAS), which includes rapid scanning of complete sets of DNA of a large number of people.
For this study, the researchers used data from the UK Biobank, which includes genetic information from 452,633 people. All the participants were asked to classify their naps during the day as “never/ rarely”, “sometimes” or “usually”. The GWAS identified 123 regions in the human genome connected with daytime napping. Then the participants wore activity monitors called accelerometers, which can provide data about daytime napping. This data also showed that the self-reports about napping were accurate.
Several other features of this study support its results. For example, the researchers obtained similar findings in an analysis of the genomes of 541,333 people collected by 23andMe, a consumer genetic-testing company. Also, a significant number of the genes near or at regions identified by the GWAS are already known to play a role in sleep.
The team also identified at least three potential mechanisms (机制) that promote napping. Some people need more shut-eye than others. A daytime nap can help make up for poor-quality sleep the night before. People who rise early may “catch up” on sleep with a nap. “This tells us that daytime napping is biologically driven and not just an environmental or behavioral choice,” says Dashti. Some of these mechanisms are linked to health concerns, such as a large waistline and increased blood pressure, though more research on those associations is needed.
27. What did the researchers at MGH focus on in their new study?
A.The causes of long napping time. |
B.The benefits of napping frequently. |
C.The reasons behind the napping habit. |
D.The genes contributing to poor sleeping quality. |
28. What can we know from the text?
A.The subjects of the GWAS came from 123 regions. |
B.Activity monitors were used to ensure reliability of the results. |
C.Researchers are looking for more genes that can play a role in sleep. |
D.American companies encourage nappíng to make people feel at ease. |
29. According to Dashti, what will the researchers study next?
A.The ways to help people improve their sleep quality. |
B.The causes of and solutions to some health concerns. |
C.The impact of environment on people’s napping choice. |
D.The connection between some health problems and the mechanisms. |
30. Which of the following can be the best title for the text?
A.Health issues caused by daytime napping. |
B.Napping considered to be an essential habit. |
C.Researchers working hard to promote napping. |
D.Biological factors playing a role in daytime napping. |