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New estimate of how much thawing permafrost will worsen warming

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Enlarge / These little round jewels near the Siberian coast are thermokarst lakes, formed when pockets of thawing permafrost deflate as the ice disappears.

Arctic permafrost has long had a sort of “here there be dragons” status when it comes to climate change. The thawing of permafrost represents a positive feedback that amplifies warming by releasing more greenhouse gas into the atmosphere. But characterizing plausible future scenarios in which that release takes place hasn’t been easy.

Making careful measurements of local permafrost thawing has enabled scientists to simulate the general behavior and incorporate that into models. So far, however, those models have been limited to the gradual change that occurs as warming temperatures allow the thawing to reach slightly greater depths each successive summer. But a new study led by Merritt Turetsky at the University of Colorado, Boulder, simulates something different, based on a recent data-gathering effort: abrupt-thaw processes.

Sudden change

Abrupt thaw can occur in a few different ways but generally relates to pockets of permafrost with a larger percentage of ice inside. If that ice melts, the soil will deflate and collapse. On hillsides, soil may slump downslope or create a new drainage gully. And in low-lying areas, it can create a new wetland or lake as water fills the depression. Both situations can accelerate thaw and carbon-release processes greatly.

A global model obviously can’t include every hillock and pond, but it can try to incorporate average behavior over a larger area. That’s what the research team did, adding abrupt thaw to climate model simulations of two scenarios of human emissions from 2000 to 2300. (Permafrost thaw is a long-term process, so stopping at 2100 doesn’t make sense.)

In the high-emissions scenario, the fast release processes released 80 ±19 billion tons of carbon by 2300. Similar simulations of gradual thaw produced around 200 billion tons. So although abrupt thaw only occurs over about 5 percent of the permafrost area in the model, it releases about 40 percent as much carbon as the gradual thaw everywhere else. A larger share of the carbon from abrupt thawing is released as methane—a more potent greenhouse gas—so the warming impacts of the two categories were roughly equivalent through the year 2100.

A gradual transition

Later in the simulations, an interesting transition takes place in the abrupt thaw lakes and wetlands. These bodies of water evolve from sources of greenhouse gas to carbon-absorbers. This is partly due to a natural ecosystem progression and partly due to the fact that they tend to drain and dry out as the region warms further. The presence of oxygen means carbon comes out as CO2 rather than methane, and vegetation also gets re-established, taking in CO2. Without this process, abrupt thaw would release a lot more carbon in the simulations.

The lower human-emissions scenario represents a moderate reduction below our current (promised) path, limiting global warming to less than 3°C. In this simulation, abrupt-thaw processes release about half as much carbon. Simulations of gradual thaw have shown that it’s possible this level of warming would produce more carbon uptake by Arctic plant growth than is released from the permafrost. However, adding in abrupt thaw would tip the scale to a positive number. Still, it’s a much smaller greenhouse gas contribution than we’d see in a high-emissions scenario.

So how does that contribution compare to human-caused emissions? Our current emissions come in at around 11.5 billion tons of carbon per year. Between gradual and abrupt-thaw emissions, the high scenario would be adding the equivalent of over 1 billion tons per year by 2100. If we followed the lower human-emissions scenario, that would drop considerably.

This study represents a first pass at these numbers, even if it’s a very involved first pass. The results indicate that the carbon released by abruptly thawing permafrost is far from trivial but also unlikely to be a monster that dwarfs the gradual processes already being simulated.

Nature Geoscience, 2020. DOI: 10.1038/s41561-019-0526-0 (About DOIs).

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Merck/J&J deal may help US get enough vaccine for all adults by end of May

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Enlarge / US President Joe Biden delivers remarks on the government’s pandemic response, including the recently announced partnership between Johnson & Johnson and Merck to produce more Johnson & Johnson vaccine, as US Vice President Kamala Harris (L) looks on at the White House in Washington, DC on March 2, 2021.

With a White House-brokered deal, vaccine giant Merck has agreed to help Johnson & Johnson boost its COVID-19 vaccine production, which is woefully behind on its manufacturing schedule.

President Joe Biden announced today that, with the new deal, the country is on track to have enough COVID-19 vaccine doses to vaccinate every adult in the country by the end of May—two months ahead of earlier plans.

“About three weeks ago, we were able to say that we’ll have enough vaccine supply for adults by the end of July,” the president said in an afternoon address. “And I’m pleased to announce today, as a consequence of the stepped-up process that I’ve ordered and just outlined, this country will have enough vaccine supply—I’ll say it again—for every adult in America by the end of May. By the end of May. That’s progress—important progress.”

Merck—a powerhouse in vaccine production, responsible for the MMR (measles, mumps, and rubella) vaccine among others—will dedicate two US facilities to making the Johnson & Johnson COVID-19 vaccine. One facility will make the vaccine and the other will provide final-stage “fill and finish” services, involving aliquoting vaccine into vials and packaging them. The help from Merck stands to perhaps double J&J’s manufacturing.

In his address Tuesday, Biden noted that his administration invoked the Defense Production Act to equip the two facilities “to the standards necessary to safely manufacture the J&J vaccine.”

In an earlier press conference, White House Press Secretary Jen Psaki suggested that the invoking of the DPA helped seal a deal between the two companies, which had previously been in talks. “There’s a difference between conversations and it moving forward—and the use of the Defense Production Act,” Psaki said. “So I’m only conveying what got it across the finish line.”

Big deal

In a $1 billion contract signed last year, J&J had committed to providing the federal government 37 million doses by the end of March and 100 million by the end of June. But, more recently, the company said it would only be able to provide 20 million doses by the end of the month, much of it coming in the final weeks.

The vaccine—a nonreplicating adenovirus-based vaccine—was granted emergency authorization from the Food and Drug Administration last weekend.

Merck had been working on a COVID-19 vaccine of its own. But in late January, the company announced that it was abandoning development after results from a Phase I trial suggested the shot resulted in immune responses weaker than those seen after natural infections.

Merck is just the latest example of a big pharmaceutical company helping rivals in their effort to mass produce COVID-19 vaccine. Sanofi—another of the world’s leading vaccine makers—and Swiss drug maker Novartis each announced deals in January to help produce the mRNA COVID-19 vaccine developed by Pfizer and BioNTech. Sanofi has also said it will help with J&J’s vaccine production in Europe.

Though the boosted supplies will aid the global immunization effort, getting shots in arms requires much more, and it’s unlikely that all American adults will be vaccinated by the end of May. Biden noted the administration’s efforts to recruit more vaccinators and set up more immunization sites. He also said he will direct states to prioritize vaccinating teachers to accelerate school reopening.

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Cuttlefish can pass the marshmallow test

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Enlarge / A common cuttlefish, Sepia officinalis, in the Marine Resources Center at the Marine Biological Laboratory, Woods Hole, MA. A new study finds the cuttlefish can delay gratification—a key feature of the famous “marshmallow test.”

Alexandra Schnell

Certain species show a remarkable ability to delay gratification, notably great apes, corvids, and parrots, while other species do not (such as rodents, chickens, and pigeons.) Add the cuttlefish to the former category.

Scientists administered an adapted version of the Stanford marshmallow test to cuttlefish and found the cephalopods could delay gratification—that is, wait a bit for preferred prey rather than settling for a less desirable prey. Cuttlefish also performed better in a subsequent learning test, according to a new paper published in the journal Proceedings of the Royal Society B. It’s the first time such a link between self-control and intelligence has been found in a non-mammalian species.

As we’ve previously reported, the late Walter Mischel’s landmark behavioral study involved 600 kids between the ages of four and six, all culled from Stanford University’s Bing Nursery School. He would give each child a marshmallow and give them the option of eating it immediately if they chose. But if they could wait 15 minutes, they would get a second marshmallow as a reward. Then Mischel would leave the room, and a hidden video camera would tape what happened next.

Some kids just ate the marshmallow right away. Others found a handy distraction: covering their eyes, kicking the desk, or poking at the marshmallow with their fingers. Some smelled it, licked it, or took tiny nibbles around the edges. Roughly one-third of the kids held out long enough to earn a second marshmallow. Several years later, Mischel noticed a strong correlation between the success of some of those kids later in life (better grades, higher self-confidence) and their ability to delay gratification in nursery school. Mischel’s follow-up study confirmed the correlation.

Mischel himself cautioned against overinterpreting the results, emphasizing that children who simply can’t hold out for that second marshmallow are not necessarily doomed to a life of failure. A more nuanced picture was offered by a 2018 study that replicated the marshmallow test with preschoolers. It found the same correlation between later achievement and the ability to resist temptation in preschool, but that correlation was much less significant after the researchers factored in such aspects as family background, home environment, and so forth. And a 2020 German study adapted the classic experimental setup using Oreos and vanilla cookies with German and Kenyan schoolchildren. That study found that kids are more likely to delay gratification when they depend on each other.

Other select species have also shown the ability to delay gratification through “future-oriented foraging.” Apes and corvids, for instance, respond to a variable and unpredictable food supply by not eating some food items immediately to prepare for any future scarcity. University of Cambridge biologist Alexandra Schnell, lead author of this latest study, wanted to explore whether cuttlefish (Sepia officinalis, a relative to the octopus and the squid), could also exhibit self-control, during a fellowship at the Marine Biological Laboratory in Woods Hole, Massachusetts. Past studies had shown that cuttlefish could optimize foraging behavior and could remember details of what, where, and when from past forages, adjusting their strategy in response to changing prey conditions. But was this future-oriented foraging evidence of self-control?

To find out, Schnell and her collaborators first conducted tests to determine preferred prey for the six 9-month-old cuttlefish used in their experiments: live grass shrimp, live Asian shore crab, and pieces of raw king prawn. The cuttlefish turned out to be fairly finicky eaters, showing the least preference for the Asian shore crab; some of the cuttlefish wouldn’t eat the crab at all. Between the remaining two types of prey, the cuttlefish showed a marked preference for the live grass shrimp over the raw king prawn.

Alexandra Schnell in the Cephalopod Mariculture Facility at the Marine Biological Laboratory, Woods Hole, Massachusetts.
Enlarge / Alexandra Schnell in the Cephalopod Mariculture Facility at the Marine Biological Laboratory, Woods Hole, Massachusetts.

Grass Foundation

For the experimental setup, the team 3D-printed a two-chamber apparatus, consisting of two black plastic drawers, each with a transparent sliding door so the cuttlefish could see the contents. Each chamber was given its own detachable, uniquely shaped symbol. The team placed the apparatus in an aquarium and then used PVC barriers at the other end of the tank to keep the cuttlefish an equal distance from both chambers.

Next, the cuttlefish went through a dual training phase. In the first, the cephalopods were placed in the aquarium and then presented with a single chamber marked with one of the visual symbols, to train the subjects to associate that space with a particular degree of accessibility to the prey. For instance, one symbol was associated with immediate accessibility to the prey (instant gratification); another was associated with delayed release, followed by access to the prey (delayed gratification); and a third was associated with inaccessibility to the prey (no gratification). In the third option, the cuttlefish would encounter a clear barrier keeping them from the prey after the sliding door was opened following a short delay.

The second training phase involved single-choice selection. There were two unmarked chambers (no associated symbols) baited with the same type of prey. When the cuttlefish made a “choice” by approaching one of the chambers, the prey in the other chamber was immediately removed. The test subjects also went through a pretest phase to teach them that the lengths of the delays in accessibility to prey would consecutively increase. In this pretest, the delay duration ranged from two seconds to 20 seconds, and each cuttlefish had to “choose” between an immediate and a delayed option.

For the actual experiment, the cuttlefish had to choose between two different prey items: it could choose to eat the raw king prawn immediately, or delay gratification for the preferred live grass shrimp. (A control group of cuttlefish had to choose between immediate access to prey and no access at all.) Subjects could see both options for the duration of the trial and could give up waiting at any point and eat the king prawn if they got tired of holding out for the grass shrimp. The team also subjected the cuttlefish to a learning task to assess cognitive performance. The cephalopods first learned to associate a visual symbol with a specific prey reward, and then the researchers reversed the situation so that the same reward was associated with a different symbol.

Schematic of the test conditions in the delay maintenance task: (a) control condition, and (b) experimental condition.
Enlarge / Schematic of the test conditions in the delay maintenance task: (a) control condition, and (b) experimental condition.

Alexandra K. Schnell et al., 2021

The results: “Cuttlefish in the present study were all able to wait for the better reward and tolerated delays for up to 50-130 seconds, which is comparable to what we see in large-brained vertebrates such as chimpanzees, crows, and parrots,” said Schnell. Furthermore, “The cuttlefish that were quickest at learning both of the associations [with the food reward] were better at exerting self-control.”

Humans may have evolved the ability to delay gratification as a means of strengthening social bonds, thereby benefiting the species as a whole. In apes, corvids, and parrots, the evolutionary driver might be linked to their use of tools and storage of food (caching behavior), as well as strengthening social bonds. But cuttlefish do not use tools or store food, and they are not a social species. Rather, cuttlefish seem to have developed this link between self-control and cognitive performance via a completely different evolutionary pathway—an example of convergent evolution.

“Cuttlefish spend most of their time camouflaging, sitting and waiting, punctuated by brief periods of foraging,” said Schnell of her working hypothesis for how the cephalopods may have developed this ability to exert self-control. “They break camouflage when they forage, so they are exposed to every predator in the ocean that wants to eat them. We speculate that delayed gratification may have evolved as a byproduct of this, so the cuttlefish can optimize foraging by waiting to choose better quality food.”

DOI: Proceedings of the Royal Society B, 2021. 10.1098/rspb.2020.3161  (About DOIs).

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“Locked” for 300 years: Virtual unfolding has now revealed this letter’s secrets

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In 1697, a man named Jacques Sennacque wrote a letter to his cousin, a French merchant named Pierre Le Pers, requesting a certified death certificate for another man named Daniel Le Pers (presumably also a relation). Sennacque sealed the letter with an intricate folding method known as “letterlocking,” a type of physical cryptography—the better to safeguard the contents from prying eyes. That letter was never delivered or opened. More than 300 years later, researchers have virtually “unlocked” the letter to reveal its contents for the first time, right down to the watermark in the shape of a bird. They described their results in a new paper published in the journal Nature Communications.

Co-author Jana Dambrogio, a conservator at MIT Libraries, coined the term “letterlocking” after discovering such letters while a fellow at the Vatican Secret Archives in 2000. The Vatican letters dated back to the 15th and 16th centuries, and they featured strange slits and corners that had been sliced off. Dambrogio realized that the letters had originally been folded in an ingenious manner, essentially “locked” by inserting a slice of the paper into a slit, then sealing it with wax. It would not have been possible to open the letter without ripping that slice of paper—evidence that the letter had been tampered with.

Dambrogio has been studying the practice of letterlocking ever since, often creating her own models to showcase different techniques. The practice dates back to the 13th century—at least in Western history—and there are many different folding and locking techniques that emerged over the centuries. Queen Elizabeth I, Machiavelli, Galileo Galilei, and Marie Antoinette are among the famous personages known to have employed letterlocking for their correspondence.

For instance, a February 8, 1587, letter from Mary, Queen of Scots, to her brother-in-law, King Henri III of France, was sealed using a so-called “butterfly lock”—just one of hundreds of locking techniques Dambrogio has compiled into a dictionary of letterlocking. Other techniques include a simple triangular fold-and-tuck, and an ingenious method known as the “dagger-trap,” which incorporates a booby-trap disguised as another, simpler type of letter lock.

Often individuals would have their own unique style of letterlocking, most notably English poet John Donne, who used at least five different letterlocking styles, one unique to him, according to Dambrogio. “So we’ve got this guy who’s known as the most inventive and witty poet of his generation, and he’s doing one of the most inventive and witty and brilliant interlocking methods you could imagine,” she told Atlas Obscura in 2018. “That is the kind of evidence you can use to say, ‘Ah, so you can actually see something of people’s personalities in the way they fold letters.'”

In 2012, Dambrogio hit the jackpot: a Yale researcher named Rebekah Ahrendt found a 17th-century trunk of undelivered letters preserved in the postal museum at The Hague, the Netherlands. The trunk belonged to Simon and Marie de Brienne, a highly connected postmaster and postmistress of their day. Now known as the Brienne Collection, the trunk contains 2,600 “locked” letters sent from all over Europe, 600 of which had never been opened.

And therein lay the challenge. “Once a document such as an unopened letter is damaged in the opening process, we lose a sense of the object as untouched and intact,” the authors wrote in their paper. Virtually opening these letters helps preserve “the material evidence” about a given letter’s internal security, “including highly ephemeral evidence about tucks and layer order, which usually leave no material trace.” 

So Dambrogio et al. turned to virtual “unwrapping” techniques, which are becoming increasing popular for the study of fragile historical documents. For instance, in 2016, an international team of scientists developed a method for virtually unrolling a badly damaged ancient scroll found on the western shore of the Dead Sea, revealing the first few verses from the book of Leviticus. The so-called En-Gedi scroll was recovered from the ark of an ancient synagogue destroyed by fire around 600 CE.

In 2019, we reported that German scientists used a combination of cutting-edge physics techniques to virtually “unfold” an ancient Egyptian papyrus, part of an extensive collection housed in the Berlin Egyptian Museum. Their analysis revealed that a seemingly blank patch on the papyrus actually contained characters written in what had become “invisible ink” after centuries of exposure to light. And earlier this year, we reported that scientists had used multispectral imaging on four supposedly blank Dead Sea Scrolls and found the scrolls contained hidden text, most likely a passage from the book of Ezekiel. While it took 10 years to determine that Mary, Queen of Scots’ final letter employed a letterlocking technique, Dambrogio et al. assert that their new virtual unfolding method could make the same determination in mere days.

For the first stage of analysis of the Brienne Collection letters, Dambrogio created her own test set of 10 model letters, which were then imaged using X-ray tomography by collaborators at Queen Mary University of London’s dental research labs, along with four original letters from the trunk. The scanner in question was designed to be especially sensitive to mapping the mineral content of teeth, but it works just as well on certain types of ink in old paper and parchment. This was followed by the painstaking process of developing the algorithms to identify and separate different layers of the folded letters, enabling Dambrogio et al. to virtually unfold and “read” the unopened letters. It also allowed them to better explore the various complicated folding systems of each letter because the algorithm can visualize crease patterns.

“We’ve been able to use our scanners to X-ray history,” said co-author David Mills of Queen Mary University of London. “The scanning technology is similar to medical CT scanners, but using much more intense X-rays which allow us to see the minute traces of metal in the ink used to write these letters. The rest of the team were then able to take our scan images and turn them into letters they could open virtually and read for the first time in over 300 years.”

In addition to finally reading Jacques Sennacque’s 1697 letter, the team found evidence for tracing the evolution of the letterlocking technology. The letters in the Brienne Collection showed a marked shift in letterlocking techniques over time, moving away from the “fold, tuck, and adhere” method, for example, to more of a “fold and adhere” approach that seems to foreshadow the modern envelope. Subsequent analysis is likely to reveal even deeper historical insights.

“Conserving intact these records of human interaction with materials, while making their secrets visible, enables a new perspective on history that is both kinetic and tactile, and which encourages new ways of thinking about the lives, emotions, and creativity of historical individuals and communities,” the authors wrote. “Doing so also challenges cultural historians to reconceptualize hidden, secret, and inaccessible materials as sites of critical inquiry. Letterlocking and virtual unfolding point to the ways that history sometimes resists scrutiny, and that resistance itself deserves patient study.”

One likely source for further study is hundreds of unopened, undelivered letters in an archive known as the Prize Papers—all confiscated by the British from enemy shops between the 17th and 19th centuries. Ultimately, “We envision a thorough, data-driven study, encompassing tens of thousands of known unopened letters plus millions more opened letters, drawing together letterlocking data globally to make persuasive, consequential statements about historical epistolary security trends,” the authors concluded. “By synthesizing traditional and computational conservation techniques, we can help further integrate computational tools into conservation and the humanities—and show that letters are all the more revealing when left unopened.”

DOI: Nature Communications, 2021. 10.1038/s41467-021-21326-w  (About DOIs).

Imaging The Brienne Collection: Scientists at Queen Mary University of London Dental Institute have been working with conservators, historians, and computational origami experts to help reveal the secrets of the Brienne Collection, a wooden chest containing over a thousand undelivered and unread letters.

Listing image by Unlocking History Research Group archive

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