Scientists use materials to make stem cells behave like human embryos

Stem cells confined in a circular shape on a soft gel display characteristic of embryonic development.
Photo Credit: University of New South Wales

A serendipitous discovery in the lab has the potential to revolutionize embryo models and targeted drug therapies.

Materials scientists at UNSW Sydney have shown that human pluripotent stem cells in a lab can initiate a process resembling the gastrulation phase – where cells begin differentiating into new cell types – much earlier than occurs in mother nature.

For an embryo developing in the womb, gastrulation occurs at day 14. But in a lab at UNSW’s Kensington campus, Scientia Associate Professor Kris Kilian oversaw an experiment where a gastrulation-like event was triggered within two days of culturing human stem cells in a unique biomaterial that, as it turned out, set the conditions to mimic this stage of embryo development.

“Gastrulation is the key step that leads to the human body plan,” says A/Prof. Kilian.

“It is the start of the process where a simple sheet of cells transforms to make up all the tissues of the body – nerves, cardiovascular and blood tissue and structural tissue like muscle and bone. But we haven’t really been able to study the process in humans because you can’t study this in the lab without taking developing embryonic tissue.

Untangling the Evolution of Complex Life

Dartmouth researchers report octopuses have high numbers of molecules linked to advanced cognition.
Photo Credit: Diane Picchiottino

Octopuses have captured the attention of scientists and the public with their remarkable intelligence, including the use of tools, engaging in creative play and problem-solving, and even escaping from aquariums. Now, their acuity may provide a critical link in understanding the evolution of complex life and cognition, including the human brain.

An international team led by researchers at Dartmouth and the Max Delbrück Center in Germany report in the journal Science Advances that octopuses are the first known invertebrates—creatures that lack a backbone and constitute roughly 95% of animal species—to contain a high number of gene-regulating molecules known as microRNAs.

The genes of two octopus species show an increase in microRNAs—which are linked to the development of advanced cells with specific functions—over evolutionary time that has so far only been found in humans, mammals, and other vertebrates.

Artificial Intelligence in Veterinary Medicine Raises Ethical Challenges

Chimmi (Chimichanga) a few hours before having his spleen removed due to a mass. Detected by Hi-Def Ultrasound by a radiologist. 7/2021
Photo Credit: Heidi-Ann Fourkiller

Use of artificial intelligence (AI) is increasing in the field of veterinary medicine, but veterinary experts caution that the rush to embrace the technology raises some ethical considerations.

“A major difference between veterinary and human medicine is that veterinarians have the ability to euthanize patients – which could be for a variety of medical and financial reasons – so the stakes of diagnoses provided by AI algorithms are very high,” says Eli Cohen, associate clinical professor of radiology at NC State’s College of Veterinary Medicine. “Human AI products have to be validated prior to coming to market, but currently there is no regulatory oversight for veterinary AI products.”

In a review for Veterinary Radiology and Ultrasound, Cohen discusses the ethical and legal questions raised by veterinary AI products currently in use. He also highlights key differences between veterinary AI and AI used by human medical doctors.

Greenland’s Glaciers Might Be Melting 100 Times As Fast As Previously Thought

A melting glacier on the coast of Greenland.
Photo Credit: Dr. Lorenz Meire, Greenland Climate Research Center.

A computer model has been created by researchers at the Oden Institute for Computational Engineering and Sciences at The University of Texas at Austin that determines the rate at which Greenland’s glacier fronts are melting.

Published in the journal Geophysical Research Letters, the model is the first designed specifically for vertical glacier fronts – where ice meets the ocean at a sharp angle. It reflects recent observations of an Alaskan glacier front melting up to 100 times as fast as previously assumed. According to the researchers, the model can be used to improve both ocean and ice sheet models, which are crucial elements of any global climate model.

“Up to now, glacier front melt models have been based on results from the Antarctic, where the system is quite different,” said lead author Kirstin Schulz, a research associate in the Oden Institute’s Computational Research in Ice and Ocean Systems Group (CRIOS). “By using our model in an ocean or climate model, we can get a much better idea of how vertical glacier fronts are melting.”

Frequent genetic cause of late-onset ataxia uncovered by a Quebec-led international collaboration

Photo Credit: whitfieldink

Discovery will improve diagnosis and open treatment possibilities for thousands of people with this debilitating neurodegenerative condition worldwide

A new study published in the New England Journal of Medicine reports the identification of a previously unknown genetic cause of a late-onset cerebellar ataxia, a discovery that will improve diagnosis and open new treatment avenues for this progressive condition.

Late-onset cerebellar ataxias (LOCA) are a heterogeneous group of neurodegenerative diseases that manifest in adulthood with unsteadiness. One to three in 100,000 people worldwide will develop a late-onset ataxia. Until recently, most patients with late-onset ataxia had remained without a genetic diagnosis.

An international team led by Dr. Bernard Brais, a neurologist and researcher at The Neuro (Montreal Neurological Institute-Hospital) of McGill University and Dr. Stephan Züchner of the University of Miami’s Miller School of Medicine, in collaboration with neurologists from the Universities of Montreal and Sherbrooke, studied a group of 66 Quebec patients from different families who had late-onset ataxia for which an underlying genetic cause had not yet been found. Using the most advanced genetic technologies, the team found that 40 (61 per cent) of the patients carried the same novel disease-causing variant in the gene FGF14, making it the most common genetic cause of late-onset ataxia in Quebec. They found that a small stretch of repetitive DNA underwent a large size increase in patients, a phenomenon known as repeat expansion.

Comet Impacts Could Bring Ingredients for Life to Europa’s Ocean

An artist's concept of a comet or asteroid impact on Jupiter's moon Europa.
Illustration Credit: NASA/JPL-Caltech

Comet strikes on Jupiter’s moon Europa could help transport critical ingredients for life found on the moon’s surface to its hidden ocean of liquid water — even if the impacts don’t punch completely through the moon’s icy shell.

The discovery comes from a study led by researchers at The University of Texas at Austin, where researchers developed a computer model to observe what happens after a comet or asteroid strikes the ice shell, which is estimated to be tens of kilometers thick.

The model shows that if an impact can make it at least halfway through the moon’s ice shell, the heated meltwater it generates will sink through the rest of the ice, bringing oxidants — a class of chemicals required for life — from the surface to the ocean, where they could help sustain any potential life in the sheltered waters.

The researchers compared the steady sinking of the massive melt chamber to a foundering ship.

NASA’s Webb Unveils Young Stars in Early Stages of Formation

Image of the Cosmic Cliffs, a region at the edge of a gigantic, gaseous cavity within NGC 3324, captured by Webb’s Near-Infrared Camera (NIRCam), with compass arrows, scale bar, and color key for reference.  The north and east compass arrows show the orientation of the image on the sky. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above).  The scale bar is labeled in light-years, which is the distance that light travels in one Earth-year. It takes 2 years for light to travel a distance equal to the length of the bar. One light-year is equal to about 5.88 trillion miles or 9.46 trillion kilometers.  This image shows invisible near-infrared wavelengths of light that have been translated into visible-light colors. The color key shows which NIRCam filters were used when collecting the light. The color of each filter name is the visible light color used to represent the infrared light that passes through that filter.  Webb’s NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center. 
Hi-Res Zoomable Image
Credits SCIENCE: Megan Reiter (Rice University) IMAGE: NASA, ESA, CSA, STScI IMAGE PROCESSING: Joseph DePasquale (STScI), Anton M. Koekemoer (STScI)

Scientists taking a “deep dive” into one of Webb’s iconic first images have discovered dozens of energetic jets and outflows from young stars previously hidden by dust clouds. The discovery marks the beginning of a new era of investigating how stars like our Sun form, and how the radiation from nearby massive stars might affect the development of planets.

The Cosmic Cliffs, a region at the edge of a gigantic, gaseous cavity within the star cluster NGC 3324, has long intrigued astronomers as a hotbed for star formation. While well-studied by the Hubble Space Telescope, many details of star formation in NGC 3324 remain hidden at visible-light wavelengths. Webb is perfectly primed to tease out these long-sought-after details since it is built to detect jets and outflows seen only in the infrared at high resolution. Webb’s capabilities also allow researchers to track the movement of other features previously captured by Hubble.

Scandinavian wolves carry many harmful mutations

Researchers from Uppsala University have discovered that each wolf in the Scandinavian wolf population has an average of approximately 100,000 harmful mutations across the entire genome.
Photo Credit: Hans Veth

In a new scientific study, researchers at Uppsala University have shown that Scandinavian wolves carry around 100,000 harmful mutations in their genome. As long as the harmful mutations can be compensated by a healthy genetic variant, this does not need to pose a problem. However, as there has been a high level of inbreeding in the wolf population, the occurrence of double harmful variants has increased with each generation.

Mutations occur constantly in all organisms, and many of the changes can have a harmful effect on survival and reproduction. However, as there are two copies of each chromosome, individuals are often protected by one of the copies remaining intact. But in the case of inbreeding, it can happen that individuals carry two copies of a harmful mutation, which leads to a problem known as inbreeding depression.

Biodegradable medical gowns may add to greenhouse gas

Photo Credit: National Cancer Institute

The use of disposable plasticized medical gowns – both conventional and biodegradable – has surged since the onset of the COVID-19 pandemic. Landfills now brim with them.

Because the biodegradable version decomposes faster than conventional gowns, popular wisdom held that it offers a greener option by less space use and chronic emissions in landfills.

That wisdom may be wrong.

Biodegradable medical gowns actually introduce harsh greenhouse gas discharge problems, according to new research published Dec. 20 in the Journal of Cleaner Production.

“There’s no magic bullet to this problem,” said Fengqi You, the Roxanne E. and Michael J. Zak Professor in Energy Systems Engineering, in the Smith School of Chemical and Biomolecular Engineering.

“Plasticized conventional medical gowns take many years to break down and the biodegradable gowns degrade much faster, but they produce gas emissions faster like added methane and carbon dioxide than regular ones in a landfill,” said You, who is a senior faculty fellow in the Cornell Atkinson Center for Sustainability. “Maybe the conventional gowns is not so bad.”

Scientists find iron cycling key to permafrost greenhouse gas emissions

Iron content gives a reddish hue to an area of ponded water in the Arctic permafrost. ORNL scientists are exploring the importance of the iron cycle on how greenhouse gases are released from thawing Arctic soils.
Photo Credit: David Graham/ORNL, U.S. Dept. of Energy

The interaction of elemental iron with the vast stores of carbon locked away in Arctic soils is key to how greenhouse gases are emitted during thawing and should be included in models used to predict Earth’s climate, Oak Ridge National Laboratory scientists found.

Researchers set out to explore and model the chemistry going on as the Arctic permafrost thaws in response to global warming. Northern permafrost soils contain an estimated 1,460 billion to 1,600 billion metric tons of organic carbon — about twice as much as in the atmosphere, according to the National Oceanic and Atmospheric Administration.

Chemical processes in the soil control how organic matter decomposes and is stored in soils and whether it converts to carbon dioxide or the more powerful greenhouse gas methane when released into the atmosphere.

Arctic soils are typically organic-rich and often have a high iron content, frequently visible as rusty deposits in flooded soils in the region, said ORNL modeler and principal investigator Benjamin Sulman. But current Earth system models do not take iron cycling into account when predicting the climate-warming potential of thawing permafrost.