The best from the science journals: Story of sleep and sea stars

Here are some of the most interesting research to have appeared in top science journals last week

Rock-a-bye baby

Published in Current Biology

Have trouble sleeping? Buy a rocking bed. Two studies published last week have found out that continuous rocking helps in falling asleep faster and sleeping more soundly. In the first study, 18 adults underwent a sleep monitoring programme in a lab and the researchers noted that the group that slept on a gentle rocking bed had more non-REM deep sleep. The second study carried on mice was able to point out that the rocking promoted sleep through a rhythmic stimulation of the vestibular system(the region in the inner ear that maintains balance).

Expanding jelly tablet

Credit: MIT

Credit: MIT

Credit: MITPublished in Nature Communications

Similar to the growing water jelly balls you have at home, MIT engineers have designed a soft tablet that can grow in your stomach and stay there for about a month. But why? The researchers say that this hydrogel device can be used to closely study the digestive system. It can even help monitor medication-taking patterns, track cancers or ulcers in the gastrointestinal tract

 

King-sized in Kuiper

Published in Nature Astronomy

The Kuiper Belt, the doughnut-shaped ring of icy objects beyond Neptune, has always fascinated astronomers. Believed to be leftovers of the early Solar System, objects floating in this belt help to understand the formation and evolution of our Solar System. Now astronomers have discovered a Kuiper belt object with a radius of about 1.3 km, the largest discovered so far. They hope to decipher more about the growth phase of objects and planets in the outer Solar System.

‘GO dough’ graphene

Credit: Northwestern University

Credit: Northwestern University

 

Credit: Northwestern UniversityPublished in Nature Communications

What happens when scientists awaken the child in them? They create play dough with a twist. A group of researchers from Northwestern University, USA has turned graphene oxide(GO) into a soft dough that can be shaped into 3D structures. The GO dough makes storage and transport of graphene oxide easier. It also has enhanced the mechanical properties of graphene and can be used to make electrocatalysts.

See you, sea stars

The sea star: A side-by-side comparison of two photographs taken near Croker Island in British Columbia. At left, thousands of sunflower sea stars swarm Croker Rock on Oct. 9, 2013. At right, the same site, three weeks later, with the sea stars vanished.

The sea star: A side-by-side comparison of two photographs taken near Croker Island in British Columbia. At left, thousands of sunflower sea stars swarm Croker Rock on Oct. 9, 2013. At right, the same site, three weeks later, with the sea stars vanished.   | Photo Credit: UC Davis

Published in Science Advances

After affecting corals and crustaceans, warming oceans have now led to a massive decline in sea star population. Researchers have pointed out that infectious viral disease and increasing sea surface temperatures are the

main reasons. Divers noted that between 2013 and 2017, the population collapsed and they were unable to find the sea stars in areas where they once reported an abundance of the species.

 

 

[“source=thehindu”]

Decreased deep sleep may signal Alzheimer’s disease: Study

Deep sleep,slumber,alzheimer's

Older people who get less deep sleep have higher levels of the brain protein tau, a sign of cognitive decline and Alzheimer’s disease, according to a study.

Slow-wave sleep is the deep sleep people need to consolidate memories and wake up feeling refreshed, said researchers at the Washington University School of Medicine in the US.

The findings, published in the journal Science Translational Medicine, suggest that poor-quality sleep in later life could be a red flag for deteriorating brain health.

“What’s interesting is that we saw this inverse relationship between decreased slow-wave sleep and more tau protein in people who were either cognitively normal or very mildly impaired, meaning that reduced slow-wave activity may be a marker for the transition between normal and impaired,” said Brendan Lucey, an assistant professor at the Washington University.

“Measuring how people sleep may be a non-invasive way to screen for Alzheimer’s disease before or just as people begin to develop problems with memory and thinking,” Lucey said.

The brain changes that lead to Alzheimer’s, a disease that affects an estimated 5.7 million Americans, start slowly and silently.

Up to two decades before the characteristic symptoms of memory loss and confusion appear, amyloid beta protein begins to collect into plaques in the brain.

Tangles of tau appear later, followed by atrophy of key brain areas. Only then do people start showing unmistakable signs of cognitive decline.

The challenge is finding people on track to develop Alzheimer’s before such brain changes undermine their ability to think clearly. For that, sleep may be a handy marker.

To better understand the link between sleep and Alzheimer’s disease, Lucey, along with David Holtzman, a professor at Washington University, and colleagues studied 119 people 60 years of age or older.

Most — 80 per cent — were cognitively normal, and the remaining were very mildly impaired.

The researchers monitored the participants’ sleep at home over the course of a normal week.

Participants were given a portable EEG monitor that strapped to their foreheads to measure their brain waves as they slept, as well as a wristwatch-like sensor that tracks body movement.

They also kept sleep logs, where they made note of both nighttime sleep sessions and daytime napping. Each participant produced at least two nights of data; some had as many as six.

The researchers also measured levels of amyloid beta and tau in the brain and in the cerebrospinal fluid that bathes the brain and spinal cord.

Thirty-eight people underwent PET brain scans for the two proteins, and 104 people underwent spinal taps to provide cerebrospinal fluid for analysis. Twenty-seven did both.

After controlling for factors such as sex, age and movements while sleeping, the researchers found that decreased slow-wave sleep coincided with higher levels of tau in the brain and a higher tau-to-amyloid ratio in the cerebrospinal fluid.

“The key is that it wasn’t the total amount of sleep that was linked to tau, it was the slow-wave sleep, which reflects quality of sleep,” Lucey said.

“The people with increased tau pathology were actually sleeping more at night and napping more in the day, but they weren’t getting as good quality sleep,” he said.

[“source-“hindustantimes”]