. Scientific Frontline

Wednesday, September 27, 2023

Understanding bacterial motors may lead to more efficient nanomachine motors

The FliG protein in the "bacterial motor"
Illustration Credit: Atsushi Hijikata, Yohei Miyanoiri, Osaka University

A research group led by Professor Emeritus Michio Homma (he, him) and Professor Seiji Kojima (he, him) of the Graduate School of Science at Nagoya University, in collaboration with Osaka University and Nagahama Institute of Bio-Science and Technology, have made new insights into how locomotion occurs in bacteria. The group identified the FliG molecule in the flagellar layer, the ‘motor’ of bacteria, and revealed its role in the organism. These findings suggest ways in which future engineers could build nanomachines with full control over their movements. They published the study in iScience

As nanomachines become smaller, researchers are taking inspiration from microscopic organisms for ways to make them move and operate. In particular, the flagellar motor can rotate clockwise and counterclockwise at a speed of 20,000 rpm. If scaled up, it would be comparable to a Formula One engine with an energy conversion efficiency of almost 100% and the capacity to change its rotation direction instantly at high speeds. Should engineers be able to develop a device like a flagellar motor, it would radically increase the maneuverability and efficiency of nanomachines. 

Curtin study suggests rare echidna noises could be the ‘language of love’

Echidnas, sometimes known as spiny anteaters, are quill-covered monotremes (egg-laying mammals) belonging to the family Tachyglossidae
Photo Credit: Emmanuel Higgins

Curtin University researchers have captured rare recordings of echidnas cooing, grunting and making a range of other sounds, but only during the breeding season.

Lead author Dr Christine Cooper, from Curtin’s School of Molecular and Life Sciences, said there had been ongoing scientific debate around the ability of echidnas to vocalize as a way of communicating or if the sounds they make are simply sniffing noises related to breathing.

“We observed wild short-beaked echidnas at Dryandra National Park, near Narrogin, Western Australia, making cooing and grunting sounds, in addition to the wheezing and exhalation noises that the animals are known to make,” Dr Cooper said.

“Our team managed to capture some of these sounds with hand-held microphones as well as a camera and microphone left unattended at the entrance to a cave popular with echidnas.

Could RNA folding play a role in the origin of life?

New research in membaneless compartments that model protocells reveals that naturally occurring chemical modifications to RNA molecules help them fold better into functional structures. Image of the structures of tRNA molecules from protocells determined by high-throughput sequencing using tRNA structure-seq are overlaid on and image of the membraneless compartments made through liquid-liquid phase separation.
(CC BY-NC-ND 4.0)
Image Credit: Bevilacqua and Keating Labs / Penn State.

New research in model protocells reveals naturally occurring chemical modifications to RNA molecules help them properly fold into functional structures

To investigate potential early steps taken by the first life to develop on Earth, researchers have been studying a model of pre-life protocells comprising membraneless compartments. Now, a team of Penn State scientists have found that RNA molecules within these compartments fold better when they have naturally occurring chemical modifications. These modifications that allow for better folding in RNAs may offer a hint into how the molecules evolved from arbitrary chemical compounds to the dynamic, organized building blocks of life. The new study, published by a team of Penn State scientists in the journal Science Advances, used high-throughput genetic sequencing to determine the structure of the RNAs, which also has implications for the design of delivery methods for RNA-based therapeutics that rely on properly folded RNAs to function.

Double Trouble: Infamous “Eagle Killer” Bacterium Produces Not One, But Two Toxins

Colony of A. hydrillicola
Photo Credit: Lenka Štenclová

The cyanobacterium Aetokthonos hydrillicola produces not just one, but two highly potent toxins. In the latest issue of the journal Proceedings of the National Academy of Sciences (PNAS), an international team led by Martin Luther University Halle-Wittenberg (MLU) and Freie Universität Berlin describes the second toxin, which had remained elusive until now. Even in low concentrations, it can destroy cells and is similar to substances currently used in cancer treatment. Two years ago, the same team established that the first toxin from the cyanobacterium is the cause of a mysterious disease among bald eagles in the USA.

Aetokthonos hydrillicola is particularly challenging for researchers. It is notoriously difficult to cultivate and produces one of its toxins only under specific conditions. The fact that it produces two toxins with very different chemical makeups is also unusual. Cyanobacteria normally produce only one toxin - and A. hydrillicola was established as the source of aetokthonotoxin in 2021. This discovery was made by Professor Susan Wilde from the University of Georgia (USA) and Professor Timo Niedermeyer, who worked at MLU until July 2023 and has now joined the researchers at Freie Universität Berlin. This toxin solved a riddle that had kept scientists busy for decades: it triggers the disease vacuolar myelinopathy (VM) among bald eagles in the United States. VM causes holes to form in the brain and, as a result, the birds lose control of their bodies. Science ran the breakthrough as a cover story at the time, and the international team picked up several awards for its work.

Tuesday, September 26, 2023

Study sheds new light on strange lava worlds

Lava worlds are likely still in the early stages of their evolution, as some theories suggest Earth too was once entirely molten.
Image Credit: NASA’s Goddard Space Flight Center/Chris Smith (KBRwyle)

Lava worlds, massive exoplanets home to sparkling skies and roiling volcanic seas called magma oceans, are distinctly unlike the planets in our solar system.  

To date, nearly 50% of all rocky exoplanets yet discovered have been found capable of maintaining magma on their surfaces, likely because these planets are so close to their host stars they orbit in fewer than 10 days. Being so close causes the planet to be bombarded by harsh weather and forces surface temperatures to the extreme, making it all but completely inhospitable to life as we know it today. 

Now, in a new study, scientists have shown that these sweeping molten oceans have a large influence on the observed properties of hot rocky Super-Earths, such as their size and evolutionary path.  

Their research, published recently in The Astrophysical Journal, found that due to lava’s extremely compressible nature, oceans of magma can cause lava-rich planets without atmospheres to be modestly denser than similarly sized solid planets as well as impact the structure of their mantles, the thick inner layer that surrounds a planet’s core.  

From Seafloor to Space: New Bacterial Proteins Shine Light on Climate and Astrobiology

Methane clathrate (white, ice-like material) under a rock from the seafloor of the northern Gulf of Mexico. Deposits such as these demonstrate that methane and other gases cross the seafloor and enter the ocean.
Photo Credit: NOAA

Gigatons of greenhouse gas are trapped under the seafloor, and that’s a good thing. Around the coasts of the continents, where slopes sink down into the sea, tiny cages of ice trap methane gas, preventing it from escaping and bubbling up into the atmosphere.

While rarely in the news, these ice cage formations, known as methane clathrates, have garnered attention because of their potential to affect climate change. During offshore drilling, methane ice can get stuck in pipes, causing them to freeze and burst. The 2010 Deepwater Horizon oil spill is thought to have been caused by a buildup of methane clathrates.

But until now, the biological process behind how methane gas remains stable under the sea has been almost completely unknown. In a breakthrough study, a cross-disciplinary team of Georgia Tech researchers discovered a previously unknown class of bacterial proteins that play a crucial role in the formation and stability of methane clathrates.

Researcher to help send swarm of marine robots on climate change quest beneath ocean ice

Retreating ice has exposed the rocky shoreline of Cape Rasmussen on the Antarctic Peninsula. Xi Yu, a West Virginia University engineer, is leading robotics research that could help a nationwide consortium of researchers learn more about glacial melt and changing levels of ocean ice.
Phot Credit: Derek Ford/University of Hawaii, Manoa

Research from West Virginia University mechanical and aerospace engineer Xi Yu could help scientists reach ocean waters hidden away beneath ice shelves. The inaccessible waters under ocean ice contain information critical to understanding the impact of climate change, and Yu said she believes multiple marine robots, carried and coordinated by an intelligent mothership, can reach those depths and communicate what they learn.

An assistant professor at the Benjamin M. Statler College of Engineering and Mineral Resources and a member of WVU Robotics, Yu has received National Science Foundation support for a three-year project developing technologies to control swarms of “passenger robots,” intended for release by their autonomous mothership into an icy subaquatic world.

She is part of a coast-to-coast network of oceanographers and engineers who have come together to collaborate on the increasingly urgent problem of how to access oceanic ice cavities. The community of partners working together toward the proof-of-concept mothership-and-passenger system originated at Oregon State University and has expanded outward to include computer engineers, roboticists, oceanographers and glaciologists from Brigham Young, Temple, Purdue and the Woods Hole Oceanographic Institution, in addition to WVU.

Deciphering the secrets of the brain

Adrian Wanner is delighted with the exceptional international recognition from the US National Institute of Health (NIH).
Photo Credit: Scanderbeg Sauer Photography

Scientific Frontline: Extended "At a Glance" Summary: Mapping the Brain's Connectome

The Core Concept: Mapping the brain's connectome is the process of creating a comprehensive structural wiring diagram of the brain's billions of neurons and their synaptic connections to understand how information is processed.

Key Distinction/Mechanism: Unlike traditional methodologies that rely on fragile, ultra-thin tissue slices prone to physical handling errors, this advanced approach utilizes thicker tissue sections. It employs a multi-beam scanning transmission electron microscope combined with broadband ion beam polishing—a technique adapted from microchip manufacturing—to iteratively remove nanometer-thin layers. This highly stable process generates superior high-resolution data, allowing artificial intelligence (AI) algorithms to reconstruct 3D neuronal networks far more accurately.

Origin/History: The foundational milestone in connectomics was the manual mapping of the nematode C. elegans (comprising just 302 nerve cells), a rigorous process completed in 1986. Building upon this history, the US National Institutes of Health (NIH) BRAIN Initiative recently awarded a $2.6 million grant to researchers at the Paul Scherrer Institute (PSI) and the Francis Crick Institute to modernize, scale, and automate this process for the mouse brain.

New insect genus discovered in one of the most biodiverse rain forest regions in the world

Capitojoppa amazonica is a large parasitoid wasp species that has only been discovered in the Allpahuyao-Mishana National Reserve in the Peruvian Amazon.
Photo Credit: Kari Kaunisto, Biodiversity Unit of the University of Turku.

The Allpahuayo-Mishana National Reserve in Peru has often been described as the most biodiverse rainforest in the world. For example, in recent decades, scientists have discovered several new bird species from the region. The researchers of the University of Turku in Finland have studied the insect biodiversity in Allpahuayo-Mishana for over twenty years. In their latest study, the scientist described a new wasp genus, Capitojoppa, to science.

In their newly published study in the journal ZooKeys. The researchers describe a new wasp genus Capitojoppa to science, categorizing it to the subfamily Ichneumoninae. 

“Wasps belonging to this subfamily are usually large and colorful, especially in the tropics, and as larvae feed internally on moth and butterfly caterpillars and pupae. We have studied the biodiversity of ichneumonines in the Allpahuyao-Mishana National Reserve with the samples collected by the researchers of the University of Turku in Finland. In our studies, we have discovered several species unknown to science which we will describe in the future. The current study kicks off this research,” says Doctoral Candidate Brandon Claridge from the Utah State University in the United States.

Increasing Steps by 3,000 Per Day Can Lower Blood Pressure in Older Adults

Photo Credit: Noelle Otto

An estimated 80% of older adults in the U.S. have high blood pressure. Maintaining healthy blood pressure can protect against serious conditions like heart failure, heart attacks, and strokes.

A new study including Linda Pescatello, distinguished professor of kinesiology in the College of Agriculture, Health and Natural Resources, found that adding a relatively minimal amount of movement, about 3,000 steps per day, can significantly reduce high blood pressure in older adults.

Pescatello worked with Elizabeth Lefferts, the lead author of the paper, Duck-chun Lee, and others in Lee’s lab at Iowa State University. They published their findings in a recent issue of the Journal of Cardiovascular Development and Disease.

“We’ll all get high blood pressure if we live long enough, at least in this country,” Pescatello says. “That’s how prevalent it is.”

Pescatello is an expert on hypertension (the clinical term for high blood pressure) and exercise. Her previous research has demonstrated that exercise can have a significant immediate and long-lasting impact on lowering blood pressure in hypertensive adults.

Stacking Order and Strain Boosts Second-Harmonic Generation with 2D Janus Hetero-bilayers

Second-harmonic generation of 2D Janus MoSSe/MoS2 hetero-bilayers is optimized by stacking order and strain.
Image Credit: ©Nguyen Tuan Hung et al.

A group of researchers from Tohoku University, Massachusetts Institute of Technology (MIT), Rice University, Hanoi University of Science and Technology, Zhejiang University, and Oak Ridge National Laboratory have proposed a new mechanism to enhance short-wavelength light (100-300 nm) by second harmonic generation (SHG) in a two-dimensional (2D), thin material composed entirely of commonplace elements.

Since UV light with SHG plays an important role in semiconductor lithography equipment and medical applications that do not use fluorescent materials, this discovery has important implications for existing industries and all optical applications.

Study shows birds that have evolved greater complexity are less biodiverse

Songbirds have less complex skeletons and are species rich
Photo Credit: cocoparisienne

A new study of the evolution of birds shows that as their skeletons become more complex, they also decrease in diversity, with fewer species as they become more specialized in their niches. The findings, published in Nature Communications, show a correlation between skeleton complexity and bird diversity for the first time, and help biologists better understand why biodiversity varies across the birds.

Researchers at the Milner Centre for Evolution at the University of Bath looked at 983 species across all major groups of living birds and measured the complexity of their skeletons by comparing the bones in their fore limbs (wings) and hind limbs (legs).

They found that less complex birds - those with a smaller difference between their fore and hind limbs - had more species diversity than those with higher complexity and a larger difference between their limbs.

For example, birds such as pigeons, gulls and songbirds (passerines) have low skeletal complexity but a high diversity of species living in varied habitats across the world.

Bladderwrack at risk of destruction as ocean acidity rises

Bladderwrack is one of the most common macroalgae growing along Sweden’s coasts. It is widespread up to the Bothnian Sea. In Europe, it grows all the way down to Portugal’s Atlantic coast.
Photo Credit: Alexandra Kinnby

Climate change is increasing carbon dioxide levels in the sea, causing bladderwrack seaweed to grow more quickly and to increase in size along the coast. However, a scientific study by researchers from the University of Gothenburg shows that this growth is illusory as, in more acidic seas, the seaweed will be unable to withstand storms and powerful waves.

Ocean acidification is a consequence of the oceans absorbing a large proportion of the carbon dioxide that is being released into the atmosphere. The drop in pH changes the conditions for the plants and animals that live in our seas. The ocean has already become more acidic and the worst-case scenario from the IPCC predicts an even further drop in pH, from 8.1 today down to around 7.7 by the end of this century.

“That might not sound very much, but pH is a logarithmic scale so it’s a big difference. We are already seeing calcifying species such as shellfish finding it more difficult to survive today,” says Alexandra Kinnby, a marine biologist at the University of Gothenburg.

Extreme heat likely to cause next mass extinction

Photo Credit: Juli Kosolapova

A new study shows unprecedented heat is likely to lead to the next mass extinction since the dinosaurs died out, eliminating nearly all mammals in some 250 million years time.

The research, published in Nature Geoscience presents the first-ever supercomputer climate models of the distant future and demonstrates how climate extremes will dramatically intensify when the world’s continents eventually merge to form one hot, dry and largely uninhabitable supercontinent.

The findings project how these high temperatures are set to further increase, as the sun becomes brighter, emitting more energy and warming the Earth. 

Tectonic processes, occurring in the Earth’s crust and resulting in supercontinent formation would also lead to more frequent volcanic eruptions, which produce huge releases of carbon dioxide into the atmosphere, further warming the planet. 

Mammals, including humans, have survived historically thanks to their ability to adjust to weather extremes, especially through adaptations such as fur and hibernating in the cold, as well as short spells of warm weather hibernation. 

Monday, September 25, 2023

Individual neurons mix multiple RNA edits of key synapse protein, study finds

In a new study of a key protein that regulates how neurons communicate via the release of neurotransmitters, scientists tracked how RNA editing affected the protein's distribution and performance. Here three different edits of complexin (yellow) resulted in different distributions of the protein in segments of motor neurons as well as different degrees of function. The left panel shows distribution of unedited complexin while the right two panels show distribution of two different edited variants.
Image Credit: Littleton Lab/Picower Institute

Neurons stochastically generated up to eight different versions of a protein-regulating neurotransmitter release, which could vary how they communicate with other cells.

Neurons are talkers. They each communicate with fellow neurons, muscles, or other cells by releasing neurotransmitter chemicals at “synapse” junctions, ultimately producing functions ranging from emotions to motions. But even neurons of the exact same type can vary in their conversational style. A new open-access study in Cell Reports by neurobiologists at The Picower Institute for Learning and Memory highlights a molecular mechanism that might help account for the nuanced diversity of neural discourse.

The scientists made their findings in neurons that control muscles in Drosophila fruit flies. These cells are models in neuroscience because they exhibit many fundamental properties common to neurons in people and other animals, including communication via the release of the neurotransmitter glutamate. In the lab of Troy Littleton, Menicon Professor in MIT’s departments of Biology and Brain and Cognitive Sciences, which studies how neurons regulate this critical process, researchers frequently see that individual neurons vary in their release patterns. Some “talk” more than others.

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