Now, a team led by McGill University researchers and members of Canada’s CHIME Fast Radio Burst collaboration has established that FRBs include radio waves at frequencies lower than ever detected before, a discovery that redraws the boundaries for theoretical astrophysicists trying to put their finger on the source of FRBs.

“We detected fast radio bursts down to 110 MHz where before these bursts were only known to exist down to 300 MHz,” explained Ziggy Pleunis, a postdoctoral researcher in McGill’s Department of Physics and lead author of the research recently published in the Astrophysical Journal Letters. “This tells us that the region around the source of the bursts must be transparent to low-frequency emission, whereas some theories suggested that all low-frequency emission would be absorbed right away and could never be detected.”

The study focussed on an FRB source first detected in 2018 by the CHIME radio telescope in British Columbia. Known as FRB 20180916B, the source has attracted particular attention because of its relative proximity to Earth and the fact that it emits FRBs at regular intervals.

The research team combined the capacities of CHIME with those of another radio telescope, LOFAR, or Low Frequency Array, in the Netherlands. The joint effort not only enabled the detection of the remarkably low FRB frequencies, but also revealed a consistent delay of around three days between the higher frequencies being picked up by CHIME and the lower ones reaching LOFAR.

“This systematic delay rules out explanations for the periodic activity that do not allow for the frequency dependence and thus brings us a few steps closer to understanding the origin of these mysterious bursts,” adds co-author Daniele Michilli, also a postdoctoral researcher in the Department of Physics at McGill.

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University of Queensland researcher Dr Anthony Romilio was part of the team that investigated the track, originally found by Associate Professor Lida Xing from the China University of Geosciences (Beijing).

“This footprint was made by a herbivorous, armoured dinosaur known broadly as a stegosaur — the family of dinosaurs that includes the famed stegosaurus,” Dr Romilio said.

“Like the stegosaurus, this little dinosaur probably had spikes on its tail and bony plates along its back as an adult.

“With a footprint of less than six centimetres, this is the smallest stegosaur footprint known in the world.

“It’s in strong contrast with other stegosaur prints found at the Chinese track site which measured up to 30 centimetres, and prints found in places like Broome in Western Australia where they can be up to 80 centimetres.”

The tiny footprint has similar characteristics of other stegosaur footprints with three short, wide, round toe impressions.

However researchers found the print wasn’t elongated like larger counterpart prints discovered at the track sites, which suggests the young stegosaur had a different behaviour.

“Stegosaurs typically walked with their heels on the ground, much like humans do, but on all fours which creates long footprints,” Dr Romilio said.

“The tiny track shows that this dinosaur had been moving with its heel lifted off the ground, much like a bird or cat does today.

“We’ve only previously seen shortened tracks like this when dinosaurs walked on two legs.”

Associate Professor Xing said that it was plausible young stegosaurs were toe-walkers.

“This could be possible as this is the ancestral condition and a posture of most dinosaurs, but the stegosaur could also have transitioned to heel-walking as it got older,” Dr Xing said.

“A complete set of tracks of these tiny footprints would provide us with the answer to this question, but unfortunately we only have a single footprint.”

Finding the tiny tracks on crowded track sites will be challenging for the researchers.

“The footprints made by tiny armoured dinosaur are much rarer than those formed by other groups of dinosaurs,” Associate Professor Xing said.

“Now that our study has identified nine different dinosaur track sites from this locality, we will look even closer to see if we can find more of these tiny tracks.”

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Within the Mathematics, Mechanics, and Materials Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), postdoctoral researcher, Dr. Vikash Chaurasia, and Professor Eliot Fried have been using energy minimization techniques to look at charged proteins on biological particles. Previously they researched cholesterol molecules but when the pandemic hit, they realized that with the methods they had developed could be applied to the new virus. They collaborated with researchers Mona Kanso and Professor Jeffrey Giacomin, from Queen’s University in Canada, to take a close look at SARS-CoV-2 and see how the shape of the virus’ ‘spikes’ (which are officially called peplomers) aid its success at spreading so prolifically. Their study was recently published in Physics of Fluids.

“When one envisions a single coronavirus particle, it is common to think of a sphere with many spikes or smaller spheres distributed across its surface,” said Dr. Chaurasia. “This is the way the virus was originally modeled. But this model is a rough sketch and over the last year, we’ve come to learn much more about what the virus looks like.”

Instead, Dr. Chaurasia pointed out, the ‘spikes’ of the coronavirus particle are actually shaped like three small spheres stacked together to form a triangular shape. This is an important consideration because the shape of a viral particle can influence its ability to disperse.

To understand this, imagine a ball moving through space. The ball will follow a curve but, as it does this, it will also rotate. The speed at which the ball rotates is called its rotational diffusivity. A particle of SARS-CoV-2 moves in a similar way to this ball although its suspended in fluid (specifically, tiny droplets of saliva). The rotational diffusivity of the particle impacts how well it can align with and attach itself to objects (such as a person’s tissues or cells) and this has been key in its ability to successfully spread from person to person so quickly. A higher rotational diffusivity will mean that the particle shakes and jitters as it follows a trajectory — and thus may have difficulty attaching to objects or efficiently bouncing off an object to continue to move through the air. Whereas a lower rotational diffusivity has the opposite effect.

Another consideration was the charge of each spike. The researchers assumed that each is equally charged. The same charges always repel each other so if there are only two spikes on a particle and they have equal charges, they’ll be situated at either pole (as far away from each other as possible). As more equally charged spikes are added, they become evenly distributed across the surface of the sphere. This provided the researchers with a geometrical arrangement from which they could calculate the rotational diffusivity.

Previously, the researchers looked at a viral particle with 74 spikes. For this new study, they used the same particle but switched out the single-bead spikes for the three-bead triangles. When they did this, the rotational diffusivity of the particle was found to decrease by 39%. Moreover, this trend was found to continue with the addition of more spikes.

This was an important finding — having a lower rotational diffusivity means that the virus particles can better align and attach themselves to objects and people. Thus, this study suggests that the triangular shaped spikes have contributed to the success of SARS-CoV-2.

“We know it’s more complicated than this,” explained Dr. Chaurasia. “The spikes might not be equally charged. Or they might be flexible and able to twist themselves. Also, the ‘body’ of the particle might not be a sphere. So, we plan to do more research in this area.”

An additional interesting feature of this research is its connection to a question asked more than a century ago by physicist J. J. Thomson, who explored how a set number of charges will be distributed across a sphere.

“I find it fascinating that a problem considered more than 100 years ago has such relevance for the situation we’re in today,” said Professor Eliot Fried. “Although this question was first posed primarily from a standpoint of curiosity and intellectual interest, it has turned out to be applicable in unexpected ways. This shows why we mustn’t lose site of the importance of fundamental research.”

The scientists at OIST and at Queen’s University intend to continue to collaborate on this kind of research to shed light on the success of SARS-CoV-2. The researchers at Queen’s University have just been awarded a Mitacs Globalink Research Award to allow for lead author Mona Kanso to travel between Canada and Japan and work more closely with OIST.