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The speed at which artificial intelligence is gaining in mathematical ability has taken many by surprise. It is rewriting what it means to be a mathematician

Scientists occasionally have a hard time figuring out whether data they are seeing is an actual physical phenomenon or just a trick of their instrumentation. A new paper in The Planetary Science Journal from Jessica Sunshine and their colleagues at the University of Maryland describes one such confusing scenario. In this case, the researchers noted some fan-like patterns across the surface of Dimorphos, the asteroid hit by NASA’s DART mission, and thought it might be a trick of their camera. But after some image correction, computation, and physical experimentation, they determined the patterns were caused by the first-ever documented cases of material transfer between two asteroids.

An analysis of ancient and modern DNA suggests the extent of convergent evolution in different peoples around the world is even greater than we thought

Scientists studying Mars may have uncovered a brand-new mineral hidden in the planet’s ancient sulfate deposits. By combining laboratory experiments with orbital data, researchers identified an unusual iron sulfate—ferric hydroxysulfate—forming in layered deposits near the massive Valles Marineris canyon system. The mineral likely formed when sulfate-rich deposits left behind by ancient water were later heated by volcanic or geothermal activity, transforming their chemistry.

Cosmic voids may seem like the emptiest places in the universe, stripped of matter, radiation, and even dark matter. But they’re far from nothing. Even in these vast empty regions, the fundamental quantum fields that fill all of space remain, carrying a small but real amount of energy known as vacuum energy, or dark energy. While this energy is overwhelmed by matter in galaxies and clusters, in the deep emptiness of cosmic voids it becomes dominant.

Cosmic voids may seem like the emptiest places in the universe, stripped of matter, radiation, and even dark matter. But they’re far from nothing. Even in these vast empty regions, the fundamental quantum fields that fill all of space remain, carrying a small but real amount of energy known as vacuum energy, or dark energy. While this energy is overwhelmed by matter in galaxies and clusters, in the deep emptiness of cosmic voids it becomes dominant.

An exploration of the validity of the Silurian hypothesis, which posits the existence of a pre-human intelligent race on Earth.

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The bottom line is this: when given the opportunity to prove his real-world prowess, Dr. Vinay Prasad failed.

The post “Vinay Prasad Loves President Trump”. That, Plus 12 Other Thoughts on the End of Dr. Vinay Prasad’s Sabbatical From UCSF first appeared on Science-Based Medicine.

When NASA’s DART spacecraft deliberately crashed into the asteroid moonlet Dimorphos, it did more than change the asteroid’s local orbit — it slightly shifted the path of the entire asteroid pair around the Sun. The impact blasted debris into space, doubling the force of the spacecraft’s hit and nudging the system’s solar orbit by a tiny but measurable amount. It marks the first time humans have altered the trajectory of a celestial object around the Sun. The result strengthens the case for using spacecraft impacts as a future planetary defense strategy.

Scientists have found a way to significantly boost “blue energy,” which generates electricity from the mixing of saltwater and freshwater. By coating nanopores with lipid molecules that create a friction-reducing water layer, they enabled ions to pass through much more efficiently while keeping the process highly selective. Their prototype membrane produced about two to three times more power than current technologies. The discovery could help bring osmotic energy closer to becoming a practical renewable power source.

US-Israeli strikes on oil facilities have caused black rain to fall on Tehran, but the black smoke filling the air is likely to be a bigger health risk

Their species name is well known, but until recently we’ve understood very little for certain about Homo habilis. Columnist Michael Marshall reveals what new fossils are telling us about the hominins that have been considered the first humans

Lunar dust can be a pain - but it’s also literally the ground we will have to traverse if we are ever to have a permanent human settlement on the Moon. In that specific use case, it’s clingy, jagged, staticky properties can actually be an advantage, according to a new paper, recently published in Research from researchers at Beihang University, who analyzed the mechanical properties of samples returned by Chang’e 6 mission to the far side of the Moon.

We’re learning that frailty can quietly arrive decades before old age, with some people in their 30s or 40s unknowingly in a pre-frail state. There are surprising ways to stay strong – and it’s not all about weight training

Taking a multivitamin every day might slightly slow the rate of ageing, but the extent to which this is relevant to our health is unclear

Jupiter's powerful, continuous aurorae dwarf those of Earth. Scientists know that Jupiter's Galilean moons created bright spots on Jupiter's northern aurora. The JWST observed these bright spots and generated infrared spectra of them for the first time. Those observations showed that Io's bright spot is extremely variable in both temperature and density, and researchers want to know why.

Even when the idea of terraforming Mars was originally put forward, the idea was daunting. Changing the environment of an entire planet is not something to do easily. Over the following decades, plenty of scientists and engineers have looked at the problem, and most have come to the same conclusion - we’re not going to be able to make Mars anything like Earth anytime soon. A new paper available in pre-print on arXiv from Slava Turyshev of NASA’s Jet Propulsion Laboratory, is a good explainer as to why.

It appears that the bonded pair of mallards at Botany Pond are here for the long term. Every morning they are waiting at the same spot for their breakfast, and in the afternoon they snooze on the rocks but swim to me for their late lunch when I whistle. Further, I saw two of our five red-eared slider turtles yesterday, swimming and sunning in the warmer weather. Here are a few photos and a video at bottom.

It seems that the ducks are residents now, and so it’s time to name them. As with last year, they appeared on the Jewish holiday of Purim and thus needed Jewish, Purim-related names. My friend Peggy Mason, co-duck-tender, scoured the Purim literature to give the ducks names (we don’t name them until we’re sure they’re going to hang around). The hen (not Esther, as I ascertained from photos published previously), is now called Vashti, named after a character in the Purim story:

Vashti (Hebrew: וַשְׁתִּי‎, romanized: Vaštī; Koine Greek: Ἀστίν, romanized: Astín; Modern Persian: وشتی, romanized: Vâšti) was a queen of Persia and the first wife of Persian king Ahasuerus in the Book of Esther, a book included within the Tanakh and the Old Testament which is read on the Jewish holiday of Purim. She was either executed or banished for her refusal to appear at the king’s banquet to show her beauty as Ahasuerus wished, and was succeeded as queen by Esther, a Jew. That refusal might be better understood via the Jewish tradition that she was ordered to appear naked. In the Midrash, Vashti is described as beautiful but wicked and vain; she is viewed as an independent-minded heroine in feminist theological interpretations of the Purim story.

That seems fairly appropriate given that there’s no other woman in the story save the heroine Esther, who saved the Jews.

A name for the drake was tougher, as the only other notable male in the Purim story is the wicked Haman, who tried to get the King to exterminate the Jews (Esther foiled that plot). And we can’t have a drake named after a genocidal maniac.  Scouring the story and remembering her Hebrew, Peggy suggested the name Armon,  which means “palace” or “fortress” in Hebrew. That’s where the whole Purim story took place. Fortunately, it’s also a Jewish man’s name, and short.

Ergo the hen and drake are now Vashti and Armon, respectively. I’ll have to do some explaining when visitors ask me the ducks’ names and how they got them. But it is cool that last year’s and this year’s ducks both arrived on Purim, though the holidays are two weeks displaced from 2025 to 2026.

Click the pictures below if you want to enlarge them.

Aaaaaand. . . here’s the pair together. I think they make quite the handsome couple:

The lovely Vashti, hopefully destined to produce this year’s brood of ducklings. Here she’s preening, sunning, and sleeping in the warm sun of Sunday:

And the regal Armon, swimming and napping:

We put five large red-eared slider turtles (Trachemys scripta elegans) into the pond last fall, and hoped they’d hibernate in custom turtle houses put on the pebble-y bottom.  Apparently they did, as we’ve seen no bodies floating on the water.  (These were five turtles saved and put in a southern Illinois pond when Botany Pond was renovated several years ago. I believe five more evacuees will come home again this Spring.)

It’s been too cold for them to show up, but yesterday I found a big one blithely sunning himself on a rock, stretching out his limbs to get the sun. (Turtles’ heads and legs are their solar panels, used to warm up the body.) Later I saw another one’s head above the water surface as it was swimming around. So we know we have at least two. Here’s the sunbather:

This is near the northern limit of the species’ distribution, as the eggs can’t survive very cold winters.

So we have our turtles and ducks: all is in place for a lovely Spring and Summer.

And a lousy movie of Armon and Vashti preening themselves after having lunch:

More good news: I’m told the duck camera, which has been re-installed, will be activated this week. Stay tuned for the link!

Some Samoyeds adjust the pitch of their howls depending on the music being played, showing a form of vocal ability they might have inherited from their wolf ancestors

Researchers have recently published a discovery that could lead to more efficient photosynthesis in many crops. It’s hard to overstate how impactful this would be, as this could significantly increase crop yields while decreasing inputs. The growing human population makes such advances critical. Even without that factor, increasing yields decreases the land intensiveness of agriculture, which has a dramatic impact on our environment and sustainability. Improved photosynthesis would be a win across the board.

Before we get into the study there are a couple of points I want to explore. When I first learned of the various research efforts to improve photosynthesis my first reaction was – why hasn’t evolution already optimized something that is so critical to all life. The first photosynthetic organisms evolved at least 3.4 billion years ago. That’s a lot of time for evolutionary tweaking. So why is efficiency still an issue? There are a couple answers, but the primary one appears to be the constraints of evolutionary history. What this means is that evolution can only work with what it has, and it cannot undo its history. Once development leads down a certain path, evolution can make variations on the path but it cannot go back in time and take a completely different path. All vertebrates are variations on a basic body plan, for example.

So what are the evolutionary constraints of photosynthesis? Photosynthesis involves using the energy from sunlight to combine carbon dioxide (CO2) with water (H2)) to make glucose and oxygen. Critical to this reaction is an enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), which fixes the carbon from CO2 into organic compounds. This enzyme, RubisCO, is responsible for over 90% of all carbon in living things. It is the most common enzyme in the world and is a cornerstone of living ecosystems, which mostly depend on energy from the sun.

RubisCO, however, is not very efficient. It does not catalyze the reaction very quickly or specifically. The most likely reason for this inefficiency is that RubisCO evolved on the ancient Earth, before the “great oxidation event”. This means it evolved when the atmosphere had lots of CO2 but no or little oxygen, therefore it did not have to distinguish between the two. This means there was no selective pressure for an enzyme that would catalyze a reaction with CO2 but not O2. RubisCO catalyzes both. By the time oxygen started to build up in the atmosphere, RubisCO was well established as the enzyme of photosynthesis. There is also a tradeoff between efficiency and specificity, meaning that the more specific RubisCO is for CO2 over O2, the slower the reaction, and the faster the reaction, the lower the specificity (the more “mistakes” the enzyme makes by catalyzing a side reaction with O2).

To be clear, scientists often use metaphors when discussing this situation. RubisCO does not really make “mistakes”, it just does what it does. And the reaction with O2 is only a “side” reaction from the perspective of what’s best for the organism and from evolutionary selective pressures (but that’s the context that matters). So evolution has tweaked RubisCO over billions of years to have the optimal balance between efficiency and specificity. It should also be noted that this side reaction with O2 is not just wasteful, it creates toxic compounds that have to be cleared. It is estimated that plants waste 30% of the energy captured from sunlight creating and then dealing with these O2 side reactions. But evolution was effectively “trapped” in this tradeoff. Organisms had been using RubisCO  for over a billion years prior to the great oxidation event and were too dependent on it to evolve a completely new method of photosynthesis.

How do we break out of this trap? For this we need another concept – stoichiometry. You remember the bunsen burners from high school science class. You have to adjust the air intake to get the flame to go from a sputtering yellow flame to a bright blue steady flame. You need just the right ratio of gas to air to optimize the efficiency of the reaction. The situation with RubisCO is similar, although simpler. We need to maximize the concentration of CO2 and minimize the concentration of O2 around the RubisCO, in order to simultaneously improve the efficiency and specificity of the reaction. These are called carbon concentrating mechanisms, or CCMs. This idea may be simple, but evolutionarily it is very difficult (judging by how often such CO2 concentrating mechanisms have evolved in nature).

Cyanobacteria and eukaryotic algae have evolved CCMs. Algae specifically evolved structures called pyrenoids which concentrate RubisCO in parts of the chloroplasts where CO2 can also be concentrated. Researchers have been trying to understand the genetics and physiology of these CCMs to see if they can be ported to land plants, specifically crops. Unfortunately, these CCM systems are complex, involving many genes working together. Plus the evolutionary distance between algae and land plants makes adapting these systems difficult.

This brings us to the latest study – which looks at the CCM in a specific type of land plant. About 8-15% of land plants have also evolved some sort of CCM, so most still use what is called the traditional C3 version of RubisCO. Perhaps the CCM in one of these branches of land plants could more easily be adopted in crops. Some plants use what it called C4, which uses a biochemical pump to move CO2 into sheath cells. This evolved only about 20-30 million years ago, and is found in maize, sorghum, sugarcane, and some tropical grasses. Another mechanism is CAM Plants (Crassulacean Acid Metabolism), which take up CO2 at night and store it as acid, then use it during the day to increase CO2 during photosynthesis.  Then there is the hornworts which concentrate RubisCO using organelles similar to algae. The recent study looks at this third mechanism.

Here’s the good news – the researchers found that hornworts (which are small ground plants) use a very simple mechanism. There is an extra tail on the C terminus of one of the subunits of RubisCO. The researchers named this region RbcS-STAR, or the STAR region of the RubisCO. This extra tail acts like velcro, causing RubisCO to stick together and clump, which is good if you want to concentrate CO2 and RubisCO in the same part of the cell. They added the STAR piece to a relative of hornwort, and it worked. They added it to Arabidopsis, an unrelated plant often used in research, and this also caused the RubisCO to clump. So they demonstrated that STAR works, even in unrelated species. This research suggests that RbcS-STAR will likely work in a diverse range of plants.

However – the research is not done yet. Essentially they have only one half of the job done. Now they need to find a way to bring high concentrations of CO2 to the clumps of RubisCO. Perhaps they can borrow the biochemical pumps from C4 plants. There is already extensive research into porting C4 photosynthesis into C3 crops, like wheat and rice. These efforts have proved challenging, because they involve complex leaf restructuring (such as increasing the density of veins). It is possible that this discovery of RbcS-STAR could offer a simpler solution to making C4 work in these plants.

Making C4 wheat or rice could increase their yield by up to 50%. That would be transformative to agriculture, and is worth the extensive research into cracking this complex problem. While the current discovery is just one possible piece to the puzzle, it is very encouraging and hopefully moves us significantly closer to a solution.

 

The post Improved Photosynthesis first appeared on NeuroLogica Blog.