Pioneering research using bacteria brings scientists a step closer to creating artificial cells with lifelike functionality

Amoeba-shaped bacteriogenic protocell: membrane (red boundary); nucleus (blue); cytoskeleton (red filaments); vacuole (red circle); ATP production (green). Scale bar, 5 μm.
Credit: Professor Stephen Mann and Dr Can Xu

Scientists have harnessed the potential of bacteria to help build advanced synthetic cells which mimic real life functionality.

The research, led by the University of Bristol and published today in Nature, makes important progress in deploying synthetic cells, known as protocells, to more accurately represent the complex compositions, structure, and function of living cells.

Establishing true-to-life functionality in protocells is a global grand challenge spanning multiple fields, ranging from bottom-up synthetic biology and bioengineering to origin of life research. Previous attempts to model protocells using microcapsules have fallen short, so the team of researchers turned to bacteria to build complex synthetic cells using a living material assembly process.

Professor Stephen Mann from the University of Bristol’s School of Chemistry, and the Max Planck Bristol Centre for Minimal Biologytogether with colleagues Drs Can Xu, Nicolas Martin (currently at the University of Bordeaux) and Mei Li in the Bristol Centre for Protolife Research have demonstrated an approach to the construction of highly complex protocells using viscous micro-droplets filled with living bacteria as a microscopic building site.

Water can be liquid, gas or ice, right? Think again

Credit: Daniel Sonoca

Scientists at the University of Cambridge have discovered that water in a one-molecule layer acts like neither a liquid nor a solid, and that it becomes highly conductive at high pressures.

Much is known about how ‘bulk water’ behaves: it expands when it freezes, and it has a high boiling point. But when water is compressed to the nanoscale, its properties change dramatically.

By developing a new way to predict this unusual behavior with unprecedented accuracy, the researchers have detected several new phases of water at the molecular level.

Water trapped between membranes or in tiny nanoscale cavities is common – it can be found in everything from membranes in our bodies to geological formations. But this nanoconfined water behaves very differently from the water we drink.

Until now, the challenges of experimentally characterizing the phases of water on the nanoscale have prevented a full understanding of its behavior. But in a paper published in the journal Nature, the Cambridge-led team describe how they have used advances in computational approaches to predict the phase diagram of a one-molecule thick layer of water with unprecedented accuracy.

They used a combination of computational approaches to enable the first-principles level investigation of a single layer of water.

Rensselaer Physics Researcher to Advance Potentially Revolutionary Experiment

 Ethan Brown is an associate professor of physics, applied physics, and astronomy
Credit: Rensselaer Polytechnic Institute

It is believed to be exceedingly rare and slow, but if it actually exists, it would redefine the laws of physics: it’s called neutrinoless double beta decay (NDBD).

Rensselaer Polytechnic Institute’s Ethan Brown, associate professor of physics, applied physics, and astronomy, has received a $285,000 grant from the Department of Energy to contribute to the nEXO experiment to prove that NDBD exists. The nEXO experiment involves the collaboration of dozens of scientists and technologists from institutions around the globe.

Double beta decay is when two neutrons simultaneously decay into two protons and emit two electrons and two electron antineutrinos in the process. With neutrinoless double beta decay, only the electrons and protons are thought to be emitted. This contradicts the accepted laws of physics, in which all particles have a complementary antiparticle.

However, almost 100 years ago, physicist Ettore Majorana hypothesized that this did not necessarily apply to particles without charge, such as the neutrino. His hypothesis is yet to be proven, but it would offer a new understanding of the universe. Since the universe is composed mostly of matter, NBDB would explain why it is not equal parts matter and antimatter.

Vets and pets to reap benefits from new drug to treat common infection

Australia’s 29 million pets look set to benefit from a more effective treatment for Giardia, a common intestinal infection in dogs and cats, thanks to a collaboration between academia and industry.

Pharmaceutical scientists from five Australian universities are partnering with veterinary pharmaceutical company Neoculi Pty Ltd to develop a new drug to treat Giardia, which affects at least 15 per cent of dogs, particularly puppies, and approximately 12 per cent of cats.

Existing treatments on the market are ineffective and have significant drawbacks, according to University of South Australia pharmaceutical scientist Professor Sanjay Garg, one of the key collaborators on the three-year project, led by the University of Newcastle.

Professor Garg says current drugs have limited effectiveness due to parasitic resistance, require multiple treatments and have toxic side effects.

“The drug we are developing is safe and effective in one single dose. We are aiming to produce a palatable formulation that pets will take without any resistance.” Prof Garg says. “It should be available within three years.”

Divorce is more common in albatross couples with shy males

A wandering albatross displaying to potential mates. Both males and females perform elaborate mating dances before bonding with a partner.
Image credit: Samantha Patrick, University of Liverpool

The wandering albatross is the poster bird for avian monogamy. The graceful glider is known to mate for life, partnering up with the same bird to breed, season after season, between long flights at sea.

But on rare occasions, an albatross pair will “divorce” — a term ornithologists use for instances when one partner leaves the pair for another mate while the other partner remains in the flock. Divorce rates vary widely across the avian world, and the divorce rate for wandering albatrosses is relatively low.

Nevertheless, the giant drifters can split up. Scientists at MIT and the Woods Hole Oceanographic Institution (WHOI) have found that, at least for one particular population of wandering albatross, whether a pair will divorce boils down to one important factor: personality.

In a study appearing today in the journal Biology Letters, the team reports that an albatross couple’s chance of divorce is highly influenced by the male partner’s “boldness.” The bolder and more aggressive the male, the more likely the pair is to stay together. The shyer the male, the higher the chance that the pair will divorce.

Are we missing a crucial component of sea-level rise?

Map of Antarctica.
Image credit: Wikimedia Commons

Across Antarctica, some parts of the base of the ice sheet are frozen, while others are thawed. Scientists show that if some currently frozen areas were also to thaw, it could increase ice loss from glaciers that are not currently major sea-level contributors.

Recent efforts using computational modeling to understand how melting ice in Antarctica will impact the planet’s oceans have focused on ice-sheet geometry, fracture, and surface melting – processes that could potentially trigger or accelerate ice-sheet mass loss. Now, researchers have identified an additional process that could have a similarly significant effect on the ice sheet’s future: thawing of the bed, known as basal thaw, at the interface of the land and the miles-thick ice sheet above it.

The new study identifies areas that are not currently losing large amounts of mass but could be poised to match some of the largest contributors to sea-level rise – such as Thwaites Glacier – if they thawed. Antarctica is roughly the size of the United States, and the susceptible regions comprise an area greater than California. The research was published Sept. 14 in Nature Communications.

“You can’t necessarily assume that everywhere that’s currently frozen will stay frozen,” said senior study author Dustin Schroeder, an associate professor of geophysics at the Stanford Doerr School of Sustainability. “These regions may be under-appreciated potential contributors.”

Crime in the realm of bacteria

Christine Kaimer (left) and Susanne Thiery have investigated how soil bacteria fight each other.
Credit: RUB, Marquard

Who would have thought of bacteria: they can sneak up other microorganisms to kill and eat them up.

Bacteria have a variety of survival strategies to provide sufficient food in their densely populated habitats. Certain types of bacteria kill microorganisms of another type, decompose the cells and absorb them as nutrients. How this works is usually unknown. A research team on the biology of microorganisms around Dr. Christine Kaimer examined these processes in more detail. Together with colleagues from the USA, the researchers at the Ruhr University Bochum (RUB) report in the journal Cell Reports on 13. September 2022.

Stop at contact

So far, little is known about the relationship between robbers and prey in the realm of bacteria. However, researchers suspect that bacterial predators can greatly change the composition of a microbiome and thus influence the ecology of their habitat. To learn more about bacterial predator-prey relationships, Christine Kaimer's team examined the predator bacterium Myxococcus xanthus, that often occurs in the ground. It has recently become known that M. xanthus kills his prey cell in direct cell-cell contact: the predator approaches a prey cell, stops when a contact is made, and then causes cell death and decomposition within a few minutes. The researchers examined the molecular mechanisms of this process in more detail.

Decarbonizing the energy system by 2050 could save trillions

Achieving a net zero carbon energy system by around 2050 is possible and profitable
Credit: Appolinary Kalashnikova

Transitioning to a decarbonized energy system by around 2050 is expected to save the world at least $12 trillion, compared to continuing our current levels of fossil fuel use, according to a peer-reviewed study by Oxford University researchers, published in the journal Joule.

The research shows a win-win-win scenario, in which rapidly transitioning to clean energy results in lower energy system costs than a fossil fuel system, while providing more energy to the global economy, and expanding energy access to more people internationally.

The study’s ‘Fast Transition’ scenario, shows a realistic possible future for a fossil-free energy system by around 2050, providing 55% more energy services globally than today, by ramping up solar, wind, batteries, electric vehicles, and clean fuels such as green hydrogen (made from renewable electricity).

Lead author Dr Rupert Way, postdoctoral researcher at the Smith School of Enterprise and the Environment, says, ‘Past models predicting high costs for transitioning to zero carbon energy have deterred companies from investing, and made governments nervous about setting policies that will accelerate the energy transition and cut reliance on fossil fuels. But clean energy costs have fallen sharply over the last decade, much faster than those models expected.

‘Our latest research shows scaling-up key green technologies will continue to drive their costs down, and the faster we go, the more we will save. Accelerating the transition to renewable energy is now the best bet, not just for the planet, but for energy costs too.’

How the brain focuses on what’s in mind

Remembering directions someone just gave you is an example of working memory. In a new study, MIT researchers show that the brain's focus on the contents of what its holding in mind derives from bursts of gamma frequency rhythms in the front of the brain.
Photo credit: George Pak

Working memory, that handy ability to consciously hold and manipulate new information in mind, takes work. In particular, participating neurons in the prefrontal cortex have to work together in synchrony to focus our thoughts, whether we’re remembering a set of directions or tonight’s menu specials. A new study by researchers based at The Picower Institute for Learning and Memory at MIT shows how that focus emerges.

The key measure in the study in Scientific Reports is the variability of the neurons’ activity. Scientists widely agree that less variability activity means more-focused attunement to the task. Measures of that variability have indeed shown that it decreases when humans and animals focus during working memory games in the lab.

In several studies between 2016 and 2018, lead author Mikael Lundqvist and co-senior author Earl K. Miller showed through direct measurements of hundreds of neurons and rigorous modeling that bursts of gamma frequency rhythms in the prefrontal cortex coordinate neural representation of the information held in mind. The information representation can be measured in the synchronized spiking of populations of individual neurons. Bursts of beta frequency rhythms, meanwhile, implement the brain’s manipulation of that information. The theory, which Miller dubbed “Working Memory 2.0” challenged a long-held orthodoxy that neurons maintain working memory information through steady, persistent activity. Proponents of that older model, which emerged from averaged measurements made in relatively few neurons, used computer-based modeling of brain activity to argue that reduced variability cannot emerge from intermittent bursts of rhythmic activity.

New method for comparing neural networks exposes how artificial intelligence works

Researchers at Los Alamos are looking at new ways to compare neural networks. This image was created with an artificial intelligence software called Stable Diffusion, using the prompt “Peeking into the black box of neural networks.”
Source: Los Alamos National Laboratory

A team at Los Alamos National Laboratory has developed a novel approach for comparing neural networks that looks within the “black box” of artificial intelligence to help researchers understand neural network behavior. Neural networks recognize patterns in datasets; they are used everywhere in society, in applications such as virtual assistants, facial recognition systems and self-driving cars.

“The artificial intelligence research community doesn’t necessarily have a complete understanding of what neural networks are doing; they give us good results, but we don’t know how or why,” said Haydn Jones, a researcher in the Advanced Research in Cyber Systems group at Los Alamos. “Our new method does a better job of comparing neural networks, which is a crucial step toward better understanding the mathematics behind AI.”

Jones is the lead author of the paper “If You’ve Trained One You’ve Trained Them All: Inter-Architecture Similarity Increases With Robustness,” which was presented recently at the Conference on Uncertainty in Artificial Intelligence. In addition to studying network similarity, the paper is a crucial step toward characterizing the behavior of robust neural networks.