The prehistoric roots of the cold sore herpes virus
Human herpes simplex virus 1 (HSV-1) is the common causes of lip- and coldsores and is estimated to infect 3.7 billion people under the age of 50. Now, recently ancient genomes suggest that the herpes virus strain behind facial herpes arose around five thousand years ago.
Previously, genetic data for herpes only went back to 1925, but researchers were able to extract samples from the remains of four ancient individuals stretching over a thousand-year period – the oldest of which dated back to the late Iron Age around 1,500 years ago.
“By comparing ancient DNA with herpes samples from the 20th century, we were able to analyse the differences and estimate a mutation rate, and consequently a timeline for virus evolution,” explains co-lead author Dr Lucy van Dorp, from the Genetics Institute at the University College London in the UK.
This calculation led to the estimate that 5,000 years ago something happened that allowed one strain of herpes to overtake all others. The authors of the new study, published in Science Advances, suggest it may have coincided with the arrival of a new cultural practice introduced from the east: romantic and sexual kissing.
Stickers that can see inside the body
Engineers have designed a stamp-sized device that sticks to skin and can provide continuous ultrasound imaging of internal organs for 48 hours – according to a new study published in Science.
The ultrasound sticker produces high resolution images by pairing a stretchy adhesive layer with a rigid array of transducers. The adhesive layer is made from two thin layers of elastomer encapsulating a middle layer of solid hydrogel. Ultrasound transducers convert electrical energy into sound energy and back again, to produce and detect sound waves.
“This combination enables the device to conform to the skin while maintaining the relative location of transducers to generate clearer and more precise images,” says co-lead author Chonghe Wang, a PhD student in Mechanical Engineering at Massachusetts Institute of Technology, US.
The current design requires the stickers be connected to instruments that translate the reflected sound waves into images, but the team is working toward wireless devices that could be wearable imaging products for patients.
Simulating fluid flow faster
Modelling the behaviour of liquids is important for a wide range of applications, from industrial processes and medical devices to computer graphics and visual simulations. But accurately simulating liquid flow remains one of the most computationally challenging aspects of modelling the real world, because it involves precisely calculating complex and time-varying pressure distributions within the liquid.
Now, researchers have made a significant breakthrough in computational speed for modelling viscous liquids, by combining efficient mathematics with the low-level parallel computational capabilities of modern computer processors, according to a new study in ACM Transactions on Graphics.
“In this research, we propose the Unsmoothed Aggregation Algebraic Multigrid method as a sophisticated multigrid framework that fully utilises modern CPU features and introduces new numerical methods,” explains co-author Han Shao, a PhD student in Applied Mathematics and Computational Sciences at King Abdullah University of Science and Technology, Saudi Arabia.
“Our framework can be used immediately by industrial users for faster simulation, using the code available on our project website.”
The oldest octopus lures in the world
Archaeologists have determined that cowrie-shell artefacts found throughout the Mariana Islands of Western Micronesia are 3500 year-old lures for hunting octopuses. Similar versions of the lures have been found on islands across the Pacific before, but these are the oldest known examples of their kind.
The lures use at least one piece of cowrie shell (Cypraea) – a type of sea snail – lashed onto a sinking stone, which is then dropped into the water and manipulated by an attached fibre line. The shell cap and an attached stick mimics the octopus’ favourite snail food, luring it out and either activating a hook on the lure or being caught by spear, net, or by hand.
Radiocarbon dating of archaeological layers in the ground was used to confirm the ages of the artefacts, which were excavated between 2011 to 2016. The research has been published in the journal World Archaeology.
Ice-sheet geology could accelerate ice loss
A new study published in Nature Geoscience suggests Antarctica’s ice streams are more vulnerable to rapid ice loss and retreat than previously thought. Researchers from the University of Western Australia, CSIRO and University of Tasmania studied Antarctica’s sub-ice geology along the continent’s Amundsen and Siple Coasts, Wilkes Land and Recovery regions, and found sedimentary basins beneath the ice at low-level positions of Earth’s crust. These basins contain large volumes of groundwater. As glaciers retreat, the basins can discharge the groundwater, which in turn leads to an increased rate of ice loss. The increase in global ocean and surface temperatures due to climate change is the driving force behind the loss of 150 billion tonnes of ice on average each year. Ice melt in turn adds to ongoing sea level rise.