. Scientific Frontline

Tuesday, March 12, 2024

History repeats as Coral Bay faces mass loss of coral and fish life

Photo Credit: Nico Smit

A perfect storm of environmental factors has seen a monumental loss of fish and coral life at a popular area of Ningaloo Reef in Western Australia’s Gascoyne region — however Curtin University research into the event shows there is hope it will recover.

In March 2022, during the annual coral spawning event, calm weather and limited tidal movement combined to trap the coral’s eggs within Bills Bay, at the town of Coral Bay.

This led to an excess of nutrients in the water which consumed more oxygen than usual — causing massive numbers of fish and corals to die from asphyxiation.

Study lead Associate Professor Zoe Richards, from Curtin’s School of Molecular and Life Sciences, said a lack of oxygen is a well-known risk for tropical coral reefs.

“Severely low oxygen levels in the ocean can create ‘dead zones’ where almost nothing can live, causing a lot of harm to nature and, in tourist areas such as Coral Bay, this can also impact the economy and community,” Associate Professor Richards said.

Monday, March 11, 2024

Tiny Tunable Nanotubes

By wrapping a carbon nanotube with a ribbon-like polymer, Duke researchers were able to create nanotubes that conduct electricity when struck with low-energy light that our eyes cannot see. In the future, the approach could make it possible to optimize semiconductors for applications ranging from night vision to new forms of computing.
Illustration Credit: Francesco Mastrocinque

It might look like a roll of chicken wire, but this tiny cylinder of carbon atoms -- too small to see with the naked eye -- could one day be used for making electronic devices ranging from night vision goggles and motion detectors to more efficient solar cells, thanks to techniques developed by researchers at Duke University.

First discovered in the early 1990s, carbon nanotubes are made from single sheets of carbon atoms rolled up like a straw.

Carbon isn’t exactly a newfangled material. All life on Earth is based on carbon. It’s the same stuff found in diamonds, charcoal, and pencil lead.

What makes carbon nanotubes special are their remarkable properties. These tiny cylinders are stronger than steel, and yet so thin that 50,000 of them would equal the thickness of a human hair.

They’re also amazingly good at conducting electricity and heat, which is why, in the push for faster, smaller, more efficient electronics, carbon nanotubes have long been touted as potential replacements for silicon.

Unprecedented heatwaves revealed by marine lab’s historic data

Photo Credit: Courtesy of University of Auckland

A unique record at the University of Auckland's Leigh marine lab shows dramatic change in the Hauraki Gulf.

A thermometer dipped in a bucket of sea water on New Year’s Day in 1967 began a unique record which shows the dramatic intensification of warming in the Hauraki Gulf.

Sea-surface readings at the Leigh Marine Laboratory north of Auckland since that time indicate the “unprecedented nature of recent marine heatwaves,” according to Dr Nick Shears of the University of Auckland, Waipapa Taumata Rau.

The number of marine heatwave days and their cumulative intensity has increased sharply since 2012, Shears and his co-authors write in a paper published in the New Zealand Journal of Marine and Freshwater Research.

In past decades, some years had no heatwaves, but that hasn’t happened since 2012. Sponges `melting,’ becoming detached from rocks and dying, along with seaweed and kelp die-offs, are among temperature effects.

Especially warm autumns and winters have likely facilitated an increase in subtropical and tropical species such as the long-spined sea urchin Centrostephanus rodgersii, a voracious herbivore which can lay waste to deep reef environments.

A Simple and Robust Method to Add Functional Molecules to Peptides

An N-terminal specific three-component [3+2] cycloaddition proceeds without affecting the highly reactive lysine residues. This reaction has been successfully applied to polypeptides of up to 26 residues.
Illustration Credit: ©Kazuya Kanemoto et al.

Peptides are short strands of amino acids that are increasingly used therapeutically, as biomaterials and as chemical and biological probes. The capacity to isolate, manipulate and label peptides and larger proteins is limited, however, by the ability to reliably attach functional molecules, such as fluorescent compounds, to peptides in locations that won't affect the three-dimensional structure and function of the short amino acid strand.

Researchers are most interested in adding functional molecules to the N-terminus, or the end of a peptide with a free amine group (NH2), of an amino acid strand in order to minimize the interference of functional molecules with the structure and function of the bound peptide. Earlier methods of attaching functional molecules to the N-terminus of peptides were insufficient for several reasons: 

  1. the functional groups would release from the peptide in human physiological conditions
  2. only one functional group could be attached to a peptide at a time 
  3. attachment of functional molecules to peptides was not uniform or
  4. reactions simply weren't efficient.

To address this issue, researchers from Tohoku University and Chuo University developed a unique chemical reaction to attach two distinct functional molecules to the N-terminus of a peptide with a glycine amino acid at the N-terminus. The researchers published their study in the journal Angewandte Chemie International Edition.

“Molecular Rosetta Stone” Reveals How our Microbiome Talks to Us

Bacteria in the gut convert bile acids produced by the liver into a wide array of new compounds. These molecules are akin to the language of the gut microbiome, allowing them to influence distant organ systems.
Photo Credit: Lakshmiraman Oza

Researchers from Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California San Diego have uncovered thousands of previously unknown bile acids, a type of molecule used by our gut microbiome to communicate with the rest of the body.

“Bile acids are a key component of the language of the gut microbiome, and finding this many new types radically expands our vocabulary for understanding what our gut microbes do and how they do it,” said senior author Pieter Dorrestein, Ph.D., professor at Skaggs School of Pharmacy and Pharmaceutical Sciences and professor of pharmacology and pediatrics at UC San Diego School of Medicine. “It’s like going from ‘See Spot Run’ to Shakespeare.”

The results, as described by study co-author and bile acids expert Lee Hagey, Ph.D, are akin to a molecular Rosetta stone, providing previously unknown insight into the biochemical language microbes use to influence distant organ systems.

Brain Waves Travel in One Direction When Memories Are Made and the Opposite When Recalled

Traveling wave propagation directions in the memory task reveal how the brain quickly coordinates activity and shares information across multiple regions.
Photo Credit: Hongui Zhang

In the space of just a few seconds, a person walking down a city block might check their phone, yawn, worry about making rent, and adjust their path to avoid a puddle. The smell from a food cart could suddenly conjure a memory from childhood, or they could notice a rat eating a slice of pizza and store the image as a new memory. 

For most people, shifting through behaviors quickly and seamlessly is a mundane part of everyday life. 

For neuroscientists, it’s one of the brain’s most remarkable capabilities. That’s because different activities require the brain to use different combinations of its many regions and billions of neurons. How it manages to do this so rapidly has been an open question for decades. 

The study

In a paper published in Nature Human Behaviour, a team of researchers, led by Joshua Jacobs, associate professor of biomedical engineering at Columbia Engineering, shed new light on this question. By carefully monitoring neural activity of people who were recalling memories or forming new ones, the researchers managed to detect how a newly appreciated type of brainwave — traveling waves — influences the storage and retrieval of memories. 

“Broadly, we found that waves tended to move from the back of the brain to the front while patients were putting something into their memory,” said the paper’s co-author Uma R. Mohan, a postdoctoral researcher at NIH and former postdoctoral researcher in the Electrophysiology, Memory, and Navigation Laboratory at Columbia Engineering. “When patients were later searching to recall the same information, those waves moved in the opposite direction, from the front towards the back of the brain,” she said. 

Halloween toy among plastics swallowed by sea turtles

A rubber witches' finger found inside a dead sea turtle.
Photo Credit: University-of-Exeter

A Halloween toy was among hundreds of plastic items found in the guts of dead sea turtles in the Mediterranean, a new study reveals.

Researchers examined 135 loggerhead turtles either washed up or killed as “bycatch” (accidentally caught) in fishing nets off northern Cyprus.

More than 40% of the turtles contained “macroplastics” (pieces larger than 5mm), including bottle tops and the Halloween toy – a rubber witch’s finger.

The research team, led by the University of Exeter and the North Cyprus Society for the Protection of Turtles (SPOT), say loggerheads are a potential “bioindicator” species that could help them understand the scale and impact of plastic pollution.

“The journey of that Halloween toy – from a child’s costume to the inside of a sea turtle – is a fascinating glimpse into the life cycle of plastic,” said Dr Emily Duncan, from Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.

“These turtles feed on gelatinous prey such as jellyfish and seabed prey such as crustaceans, and it’s easy to see how this item might have looked like a crab claw.”

Researchers uncover protein responsible for cold sensation

Image Credit: Copilot AI Generated 

University of Michigan researchers have identified the protein that enables mammals to sense cold, filling a long-standing knowledge gap in the field of sensory biology.

The findings, published in Nature Neuroscience, could help unravel how we sense and suffer from cold temperatures in the winter, and why some patients experience cold differently under particular disease conditions.

“The field started uncovering these temperature sensors over 20 years ago, with the discovery of a heat-sensing protein called TRPV1,” said neuroscientist Shawn Xu, a professor at the U-M Life Sciences Institute and a senior author of the new research.

“Various studies have found the proteins that sense hot, warm, even cool temperatures—but we’ve been unable to confirm what senses temperatures below about 60 degrees Fahrenheit.”

In a 2019 study, researchers in Xu’s lab discovered the first cold-sensing receptor protein in Caenorhabditis elegans, a species of millimeter-long worm that the lab studies as a model system for understanding sensory responses.

AI research gives unprecedented insight into heart genetics and structure

Image Credit Copilot AI Generated

A ground-breaking research study has used AI to understand the genetic underpinning of the heart’s left ventricle, using three-dimensional images of the organ. It was led by scientists at the University of Manchester, with collaborators from the University of Leeds (UK), the National Scientific and Technical Research Council (Santa Fe, Argentina), and IBM Research (Almaden, CA).

The highly interdisciplinary team used cutting-edge unsupervised deep learning to analyze over 50,000 three-dimensional Magnetic Resonance images of the heart from UK Biobank, a world-leading biomedical database and research resource.

The study, published in the leading journal Nature Machine Intelligence, focused on uncovering the intricate genetic underpinnings of cardiovascular traits. The research team conducted comprehensive genome-wide association studies (GWAS) and transcriptome-wide association studies (TWAS), resulting in the discovery of 49 novel genetic locations showing an association with morphological cardiac traits with high statistical significance, as well as 25 additional loci with suggestive evidence.  

The study's findings have significant implications for cardiology and precision medicine. By elucidating the genetic basis of cardiovascular traits, the research paves the way for the development of targeted therapies and interventions for individuals at risk of heart disease.

How Proteins Control Genes to Prevent our Cells from Maldevelopment

Ole Nørregaard Jensen is a professor and head of research at the Department of Biochemistry and Molecular Biology.
Photo Credit: Stefan Kristensen

Every time a cell in our body prepares to divide, an extremely complex process begins to ensure that the mother cell's DNA is copied into a new daughter cell along with all the correct instructions for which genes on the DNA strand should be turned off and which should be activated.

If errors occur in this process and the new cell is not identical to the mother cell, damage and disease may occur.

Researchers are therefore interested in learning more about these processes and why the copying of DNA and instructions sometimes goes wrong.

Constant DNA replication of the cell

All humans have a unique DNA strand, originating from a single cell: the fertilized egg cell, which has divided and created the billions of cells that make up the whole human being. They all contain a copy of the DNA strand created at fertilization. However, different cells decode the DNA in different ways, allowing for the formation of more than 200 different cell types. Some cell types die quickly and need to be replaced many times during life; for example, skin cells and intestinal cells are renewed every few days. Each time a new cell is created, a copy of the unique DNA strand is made for the new cell.

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