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An AI-assisted analysis of satellite images suggests the vapour trails produced by aircraft have a net cooling effect in the daytime because they reflect sunlight back into space

Biosafety Now is fine working with a pro-virus, misinformation doctor to prevent a potential pandemic. What about a doctor who worked with patients and countered misinformation during an actual pandemic?

The post A “Biosafety” Organization Partnering With Dr. Jay Bhattacharya To Guard Against Viruses Is Like A Zebra Teaming Up With A Lion To Promote Vegetarianism first appeared on Science-Based Medicine.

Voice assistants can build profiles of their users’ habits and preferences, but the consistency and accuracy of these profiles vary

Venus is often described as a hellscape. The surface temperature breaches the melting point of lead, and though its atmosphere is dominated by carbon dioxide, it contains enough sulfuric acid to satisfy the comparison with Hades.

But conditions throughout Venus’ ample atmosphere aren’t uniform. There are locations where some of life’s building blocks could resist the planet’s inhospitable nature.

Among the rocky planets, Venus has by far the largest atmosphere by volume. So, while its surface is inhospitable, its atmosphere has regions that are the most Earth-like of anywhere else in the Solar System. Scientists have wondered if life could survive in parts of the planet’s upper atmosphere, and the discovery of the potential biomarker phosphine (though it was later disproved) generated more interest.

Some research suggests that life could exist within Venus’ voluminous clouds. Image Credit: Abreu et al. 2024.

One reason Venus keeps coming up in discussions around habitability is that it’s accessible, whereas exoplanets aren’t. Venus is easily reached, and we currently have one orbiter in place, the Japanese Akatsuki spacecraft. Three other missions to Venus are planned for the mid-2030s: NASA’s Veritas and DAVINCI and the ESA’s EnVision.

Nobody is convinced we’ll find life on Venus. But the planet can teach us a lot about chemistry and biology and their limits.

In new research, a team of scientists tested different building blocks under Venus-like conditions to see if they can withstand the planet’s perilous nature. The research is “Simple lipids form stable higher-order structures in concentrated sulfuric acid.” The lead author is Daniel Duzdevich from the Department of Chemistry at the University of Chicago. The paper is in pre-print now and has been submitted to the journal Astrobiology.

Venus’ surface isn’t a candidate for habitability. But regions in its atmosphere may be. The issue is that much of Venus’ sulfuric acid is concentrated in discrete clouds rather than diffused throughout its atmosphere.

“The Venusian surface is sterilizing, but the cloud deck includes regions with temperatures and pressures conventionally considered compatible with life. However, the Venusian clouds are thought to consist of concentrated sulfuric acid,” the authors explain.

Cloud structure in the Venusian atmosphere in 2016, revealed by observations in the two ultraviolet bands by Akatsuki. Credit: Kevin M. Gill

They wanted to test if any of life’s “fundamental features” could withstand Venus’ challenging environment. Can any of life’s chemistry resist sulfuric acid?

“Organic chemistry in concentrated sulfuric acid is rarely studied yet surprisingly rich, with recent work supporting the notion that complex organic molecules, including amino acids and nucleobases can be stable in this unusual solvent,” the authors write.

If simple organic molecules can remain stable in sulfuric acid, it’s an interesting observation in favour of life. But it takes more complexity than that, and that’s what this research focuses on.

“One fundamental feature of life is cellularity: the differentiation of “inside” (the contents of a cell, including information, molecules, and all their interactions) and “outside” (the environment), in addition to a mechanism for communication and exchange between the two,” Duzdevich and his co-researchers write.

The researchers focused on lipids, the membranes that define cells. Lipids are the foundation of cellular structure, not only as membranes between cells but also as membranes that create distinct parts of the interior of cells. “The cell membrane is especially important in extreme environments because it must help maintain the homeostasis of the intracellular environment against otherwise harsh external conditions,” the authors write.

The researchers performed lab experiments to determine whether lipids can withstand Venus’ harsh environment. They asked two questions: Can simple lipids resist decomposition by sulfuric acid, and can the lipids form stable higher-order structures like they do in cells?

The researchers placed masses of lipids in vials and exposed them to different concentrations of sulfuric acid and measured each vial at specific intervals. Their results show that some lipids can survive exposure to the acid and even form structures.

This figure from the research shows the vesicle-like structures that formed after concentrated sulfuric acid was added to solid lipids. Each panel is a different region of the same sample taken on the same day. Subsequent images showed that the structures remained intact even after seven days. Image Credit: Duzdevich et al. 2024.

Interested readers can explore the detailed chemistry for themselves.

In summary, the results suggest that stable membranes can form and persist in the presence of sulfuric acid. Life uses water as a solvent because it’s a polar molecule, can form networks of hydrogen bonds, has a high heat capacity, and, of course, is abundant on Earth. But it’s not abundant everywhere.

Critically, this study shows that some aspects of the chemistry of life don’t require water as a solvent. Instead, they can tolerate and use sulfuric acid as a solvent. “Here, we show the unexpected stability of complex membranous structures in another polar solvent: concentrated sulfuric acid,” the authors write.

What does this mean for exoplanet habitability and astrobiology?

“Concentrated sulfuric acid as a planetary solvent could be widespread on exoplanets, either on exo-Venuses or on other rocky planets that are desiccated as a result of the stellar activity of their host star,” the researchers explain.

And, of course, sulfuric acid is present in large amounts at Venus.

“Concentrated sulfuric acid is also present in our immediate planetary vicinity as a dominant liquid in the clouds of Venus, further emphasizing its importance for planetary science, planetary habitability, and astrobiology,” the authors write.

The question of whether life could somehow survive in Venus’ clouds is one that won’t go away. We’re new at the astrobiology game, and we’re simply not in a position to rule things out. It might seem far-fetched, but science is an evidence game, and evidence can be surprising.

This study doesn’t present evidence that can answer the question—big questions like this are answered incrementally—but it does present an intriguing result.

“By demonstrating the stability of lipid membranes in this aggressive solvent, we have taken a significant step forward in exploring the potential habitability of the concentrated sulfuric acid cloud environment on Venus,” the authors conclude.

The post Another Building Block of Life Can Handle Venus’ Sulphuric Acid appeared first on Universe Today.

By 2100, hospitalizations from diarrheal diseases are predicted to increase in the city of Dhaka in Bangladesh as a result of climate change, even if global warming stays under 2 degrees Celsius, according to a new study.

Astronomers listened for radio signals emanating from planets in the TRAPPIST-1 system, but found no evidence of any interplanetary communications

We are more likely to use an ineffective treatment after slight symptom improvement, even when the changes are coincidental.

The post Post Hoc Bias in Medicine first appeared on Science-Based Medicine.

Each year, about 2.2 million bone-grafting procedures are performed worldwide, the gold standard of care being autografting, which uses the patient's own bone for tooth implantation and to repair and reconstruct parts of the mouth, face and skull.

Using mathematical modeling, researchers found a way to maintain cooperation without relying on complex norms or institutions.

A 2020 microlensing event was caused by a planetary system with an Earth-like planet and brown dwarf. The star type was uncertain. The team has determined that the star is a white dwarf, a system resembling what our sun-Earth system will look like in 8 billion years. The good news: the planet survived its star's red giant phase, so maybe Earth will too. The bad news: it's still uninhabitable.

Researchers tested an advanced publicly available genAI model, GPT-4, to determine its ability to answer questions across five key areas of patient safety in the 50-question self-assessment for the Certified Professional in Patient Safety (CPPS) exam, a standardized multiple-choice certification exam for patient safety professionals. GPT-4 answered 88% of the questions correctly, demonstrating a high level of performance.

Researchers have studied how nanoplastic affects aquatic organisms in lakes and rivers. The results are surprising and the researchers are the first to show that some species are being wiped out, while others -- such as cyanobacteria that contribute to algal blooms -- are completely unaffected.

Astronomers have published a gigantic infrared map of the Milky Way containing more than 1.5 billion objects -- the most detailed one ever made. Using the European Southern Observatory's VISTA telescope, the team monitored the central regions of our Galaxy over more than 13 years. At 500 terabytes of data, this is the largest observational project ever carried out with an ESO telescope.

Squinting into the treetops won't reveal the tiny organisms up there. But these creatures leave clues, in the form of DNA, on the leaves and branches. Now, researchers report that they have developed a way to collect this genetic material: a drone with a specialized fabric probe. The team flew the drone above the rainforest and, based on DNA collected by the probe, identified the invertebrates in the canopy.

Scientists successfully tested a new way to produce sustainable jet fuel from lignin-based agricultural waste. The team's research demonstrated a continuous process that directly converts lignin polymers, one of the chief components of plant cells, into a form of jet fuel that could help improve performance of sustainably produced aviation fuels.

In a surprise finding, astronomers using NASA's Hubble Space Telescope have discovered that the blowtorch-like jet from a supermassive black hole at the core of a huge galaxy seems to cause stars to erupt along its trajectory. The stars, called novae, are not caught inside the jet, but apparently in a dangerous neighborhood nearby.

Scientists have used pressure with a twisting shear to permanently deform silicon, an important material for electronics. The resulting changes in silicon's microstructure produce material phases that feature different and potentially useful properties.

Scientists have used pressure with a twisting shear to permanently deform silicon, an important material for electronics. The resulting changes in silicon's microstructure produce material phases that feature different and potentially useful properties.

The key insight with a new strategy for training protein engineering models, called EvoRank, is to harness the natural variations of millions of proteins generated by evolution over deep time and extract the underlying dynamics needed for workable solutions to biotech challenges.

A research team has developed a new fluorine-free binder and electrolyte designed to advance eco-friendly, high-performance battery technology.