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Gizmorama - June 5, 2017

Good Morning,


Feeling stressed? If so, there's a wristband device that has been developed to calm down the wearer. Talk about wearing your heart on your sleeve...

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin


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*- New wristband device promises to reduce wearer's stress -*

According to a new study, the feeling of a heartbeat-like rhythm on a person's wrist has a measurable calming effect.

Inspired by research revealing the soothing effects of slow musical rhythms, scientists at Royal Holloway, University of London designed a wearable, wristwatch-like device called a dopper, which delivers a heartbeat-like stimulation.

"High arousal is correlated with increased heart rate, whereas calmness is physiologically correlated with lower heart rate," Manos Tsakiris, a professor of psychology at RHUL, said in a news release. "We also intuitively associate higher and lower heart rate with anxiety or high arousal, and calmness."

Wearers reported lower levels of stress, and skin conductance tests proved participants were less easily aroused while sporting the dopper.

To test the device's effects on stress, researchers had study participants prepare a speech for public performance. All participants wore the dopper, which scientists explained was being used to measure blood pressure.

The doppers worn by half of the participants were turned on, delivering a heartbeat-like stimulation at a pace slower than the wearer's resting heart rate. The doppers worn by the other participants remained unengaged.

Those sporting working doppers showed slower skin conductance responses and reported lower anxiety levels.

Researchers shared their findings in the journal Nature.

"Wearable devices are becoming ubiquitous in everyday life, but across the board their primary aim is to quantify our activity," Tsakiris said. "The results we got suggest that, rather than measuring ourselves, we can instead harvest our natural responses to heartbeat like rhythms in ways that can assist people in their everyday life."



*- Scientists use molecular clock to date oldest animal ancestor -*

Determining when life emerged is a difficult question, but it's one many scientists remain interested in.

New research questions the accuracy of a recent model that suggests the first animals emerged 1.2 billion years ago, several hundred million years earlier than the oldest fossil.

The oldest known fossil is a little more than 500 million years old. But every few years, an older fossil is discovered. In recent decades, scientists employed an alternative, fossil-free approach to dating the origin of animal life.

In the 1960s, Nobel winner Linus Pauling pioneered a genetic measurement method known as the molecular clock. The logic of the molecular clock relied on the assumption that genetic mutations accumulate in the genomes of animal lineages at a fixed rate. Early uses of the method estimated that the earliest animal ancestor existed roughly 1.5 billion years ago.

The prediction sparked intense debate among evolutionary sciences. Many researchers challenged the assumption that mutations accumulate at a fixed rate.

Over the last decade, molecular clock calculations have relaxed the rate of mutation accumulation and the divergence of animal lineages. The relaxed clock models suggest the first animals emerged no more than 850 million years ago.

However, a newer molecular clock model, dubbed RelTime, dates the origin of animal life to 1.2 billion years ago.

Researchers in Europe decided to take a closer look at the math behind the RelTime clock. They published a critique of the model in the journal Genome Biology and Evolution.

"What caught our attention was that results obtained using RelTime were in strong disagreement with a diversity of different studies, from different research groups and that used different software and data, all of which broadly agreed that animals are unlikely to be older than approximately 850 million years," Philip Donoghue, an earth scientist at the University of Bristol, said in a news release.

Most molecular clocks rely on Bayesian logic to relax the clock. The RelTime clock uses alternative statistical analysis methods.

"Estimating divergence times is difficult and different relaxed molecular clock methods use different approaches to do so," said Jesus Lozano-Fernandez, a scientist from the University of Bristol. "However, we discovered that the RelTime algorithm failed to relax the clock along the deepest branches of the animal tree of life."

Researchers argue the RelTime model suffers from the same inaccuracies as the earliest molecular clocks.

"This clearly indicates that older ideas suggesting that animals might be twice or three times as old as the oldest animal fossil are erroneous and only emerge when changes in mutation rate are incorrectly estimated," said Bristol professor Davide Pisani.

***

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