Posts Tagged ‘oxygen’
“Good night, sleep tight, don’t let the bedbugs bite”*…
As Rodrigo Pérez Ortega reports, that admonition has a very long history…
Long before rats roamed sewers and cockroaches lurked in kitchen corners, another unwelcome guest plagued early civilizations. A new genomic study published today in Biology Letters suggests that bedbugs—the blood-feeding insects that haunt our hotel stays—were the first urban pests, proving an itchy menace for tens of thousands of years.
“This is really amazing,” says Klaus Reinhardt, an evolutionary biologist at the Dresden University of Technology who was not involved in the new study. “I think the hypothesis is quite solid.” Still, other researchers quibble over whether bedbugs can indisputably claim that title.
Many species of bedbugs depend on us—and our blood—to survive, but long ago, their prey of choice was probably exclusively bats. Genetic evidence suggests that about 245,000 years ago, some bedbugs made the jump to early humans.
This split led to two genetically distinct bedbug lineages. One kept feeding on bats and today remains largely confined to caves and natural habitats in Europe and the Middle East. The other followed humans into modern dwellings. Exactly how that scenario played out remained a mystery, however. That’s why Warren Booth, an evolutionary biologist at the Virginia Polytechnic Institute and State University, and his team set out to study the genome of the common bedbug (Cimex lectularius) in depth…
… [Their findings make] bedbugs strong contenders for the title of the world’s first true urban pest that relies solely on humans, the researchers claim. Unlike more recent urban interlopers that feast on our stored food and enjoy our cozy homes—like the German cockroach (Blattella germanica), which formed a close association with humans just 2000 years ago, or the black rat (Rattus rattus), whose commensal relationship began about 5000 years ago—bedbugs may have started parasitizing humans just as our ancestors started building permanent settlements…
… the new findings underscore how humans have shaped the evolution of urban insects. Compared with their bat-feeding cousins, human-feeding bedbugs are smaller, less hairy, and have larger limbs—adaptations likely suited to navigating smooth walls and synthetic bedding. Today’s bedbugs also carry many DNA mutations linked to insecticide resistance, a relatively recent trait that reflects the pressures of modern pest control. “They’re a remarkable yet horrible species,” Booth says.
Understanding how these pests evolved together with us could help improve strategies for controlling them, especially as cities continue to grow—and as bedbugs now feed on the poultry we raise. Further research could also help us understand how our own immune system evolved, since some people develop allergies for bedbug bites. As a start, Booth and his team are analyzing centuries-old bedbug specimens in museums, to track how the insects’ genomes—and populations—have evolved over the past century alongside us.
“There’s a pretty intimate association, whether we like it or not,” Booth says. “That’s not going away anytime soon.”…
“Bedbugs may be the first urban pest,” from @rpocisv.bsky.social in @science.org.
* common children’s rhyme
###
As we contemplate the chronicle of a co-evolved curse, we might recall that it was on thus date in 1789 that Richard Kirwan published his essay in support of the phlogiston theory (the belief, that dates to alchemical times, in the existence of a fire-like element (dubbed “phlogiston”) contained within combustible bodies and released during burning. Kirwan was among the last of its advocates.
A well-regarded scientist in the late 18th and early 19th centuries, Kirwan met and corresponded with Black, Lavoisier, Priestley, and Cavendish. Indeed, while scientific history remembers him as a defender of an incorrect theory, his work probably spurred Priestley and Lavoisier, who respectively discovered and named the actual elemental agent of combustion, oxygen.
But Kirwan is also remembered for a personal eccentricity (one of many) relevant to this post: he hated bugs (especially flies). He paid his servant a bounty for each one they killed.
“Food is simply sunlight in cold storage”*…
Increasingly, as Patrick Sisson explains, that’s literally true…
If you had to identify a specific type of real estate that has seen its value increase because of changing consumer eating habits, global demographic shifts, worldwide pandemic preparedness, and US export policy — while its importance to reducing global carbon emissions and adapting to climate change rise in tandem — refrigerated warehouses may not be your first pick.
But there’s a strong case to be made that the expansion and evolution of the cold-storage industry — often called the “cold chain” — will play a significant role in energy, environmental, and economic news in the 21st century. Cold storage facilities aren’t fun places to visit; some are kept so frigid, at minus 50 degrees Fahrenheit, that the workers who toil in these windowless spaces rotate in 15-minute shifts, despite their heavy protective gear…
… refrigerated warehouses are great to build and own. Investors and developers expect 8 to 10% annual growth in this specialized real estate, according to Adam Thocher, SVP of Global Programs and Insights at the Global Cold Chain Alliance (GCCA). That’s made it a profitable real-estate niche…
The ability to more easily cool and freeze food for storage, preparation, and distribution has revolutionized grocery shelves, home cooking, and restaurants for decades, and will continue to do so for years because it taps into every trend all at once. Growing fast-casual restaurant chains, last-mile delivery, a surging global middle class seeking more protein, and the explosion in healthy, organic produce and industrialized frozen food, all need cold storage…
The pandemic accelerated these trends, spiking frozen-food sales in the US to over $74 billion in 2023, a $10 billion increase in just three years, and leading to a wave of refrigerator purchases by Chinese consumers. The need to refrigerate Covid vaccines underscored how important these sites are to global health. Even Ozempic and similar blockbuster anti-obesity drugs need to be stored at 46 degrees F. And the rest of the world is increasingly asking why, if you can always get a Granny Smith apple in New York, can’t you get one in Beijing or London?…
The GCCA estimates there is at least 7.4 billion cubic feet of cold storage worldwide, and 3.7 billion in the US alone, but that’s a vast understatement, Thocher said. The alliance only looks at partial data from 92 countries (not including China) and governments tend to be cagey about sharing his kind of data because of economic and food-security concerns, since these sites are crucial parts of food infrastructure and can reveal levels of economic activity…
Food security has become a global challenge with a growing population, Peters said, especially since roughly 30% of global food production is lost, making increasing supply and reducing food waste imperative. That’s extremely tricky when the critical loss of arable land and desertification, due to climate change, strengthens the case for cold-storage warehouses, which, because of their vast energy use, contribute to that very problem. A 2023 Columbia University study found the sector responsible for 3.5% of total global emissions. The cold-storage industry has responded with more energy-efficient designs and less harmful ammonia-based refrigerants, but it adds an additional challenge to efforts to ramp up sustainable energy production.
“This is a real system-level challenge, a wicked problem,” [Toby Peters, professor of the cold economy at the UK’s Birmingham Energy Institute] said. “My exam question is, how do we feed 9 billion people while economically empowering 400 million small farmers, all without using diesel?”…
Diets, demographics, desertification are all fueling “The Hot Business of Cold Storage,” by @patrickcsisson in @sherwood_news.
* John Harvey Kellogg
###
As we chill, we might recall that it was on this date in 1903 that Carl von Linde received two U.S. patents for his Linde oxygen process and associated equipment (Nos. 728,173 and 727,650). Linde had already invented the first industrial-scale air separation and gas liquefaction processes, which led to the first reliable and efficient compressed-ammonia refrigerator (in 1876).
In 1901, Linde had began work on a technique to obtain pure oxygen and nitrogen based on the fractional distillation of liquefied air. His 1903 patents were steps in that direction.
Linde founded a company to commercialize access to these pure gases. Now known as Linde plc (but formerly known variously as the Linde division of Union Carbide, Linde, Linde Air Products, and Praxair), it has become the world’s largest producer of industrial gases– and ushered in the creation of the global supply chain for industrial gases that serves the global cold chain.
“Some say the world will end in fire, some say in ice.”*…
Ethan Siegel reminds us that the world– the living world– almost did end in ice…
… one event came closer than any other to bringing an end to life on Earth: a catastrophe known as either the Great Oxidation Event or the Great Oxygenation Event. Oxygen, one of the hallmark characteristics of our living Earth, was a tremendous destructive force when it first arrived in any sort of meaningful abundance some ~2 billion years after Earth first took shape. The slow alteration of our atmosphere by the gradual addition of oxygen proved to be fatal to the most common types of organism that were present on Earth at the time. For several hundred million years, the Earth entered a horrific ice age which froze the entire surface: known today as a Snowball Earth scenario. This disaster almost ended life on Earth entirely. Here’s the story of our planet’s near-death, culminating in life’s ultimate survival story…
For roughly 300 million years, the Earth was frozen: “What was it like when oxygen killed almost all life on Earth?” from @StartsWithABang in @bigthink. Eminently worth reading in full.
* Robert Frost, “Fire and Ice“
###
As we contemplate change, we might send chilly birthday greetings to Raoul Pictet; he was born on this date in 1846. Remembered as a pioneer in cryogenics, Pictet was a Swiss chemist who spent much of his career trying to produce very low temperatures (in order to produce ice for refrigeration)– which led him to the creation of liquid oxygen in 1877 (for which he’s credited as co-discoverer, as French scientist Louis-Paul Cailletet, working completely separately, also produced liquid oxygen that year).
“To sleep: perchance to dream: ay, there’s the rub”*…
I’m not the first person to note that our understanding of ourselves and our society is heavily influenced by technological change – think of how we analogized biological and social functions to clockwork, then steam engines, then computers.
I used to think that this was just a way of understanding how we get stuff hilariously wrong – think of Taylor’s Scientific Management, how its grounding in mechanical systems inflicted such cruelty on workers whom Taylor demanded ape those mechanisms.
But just as interesting is how our technological metaphors illuminate our understanding of ourselves and our society: because there ARE ways in which clockwork, steam power and digital computers resemble bodies and social structures.
Any lens that brings either into sharper focus opens the possibility of making our lives better, sometimes much better.
Bodies and societies are important, poorly understood and deeply mysterious.
Take sleep. Sleep is very weird.
Once a day, we fall unconscious. We are largely paralyzed, insensate, vulnerable, and we spend hours and hours having incredibly bizarre hallucinations, most of which we can’t remember upon waking. That is (objectively) super weird.
But sleep is nearly universal in the animal kingdom, and dreaming is incredibly common too. A lot of different models have been proposed to explain our nightly hallucinatory comas, and while they had some explanatory power, they also had glaring deficits.
Thankfully, we’ve got a new hot technology to provide a new metaphor for dreaming: machine learning through deep neural networks.
DNNs, of course, are a machine learning technique that comes from our theories about how animal learning works at a biological, neural level.
So perhaps it’s unsurprising that DNN – based on how we think brains work – has stimulated new hypotheses on how brains work!
Erik P Hoel is a Tufts University neuroscientist. He’s a proponent of something called the Overfitted Brain Hypothesis (OBH).
To understand OBH, you first have to understand how overfitting works in machine learning: “overfitting” is what happens when a statistical model overgeneralizes.
For example, if Tinder photos of queer men are highly correlated with a certain camera angle, then a researcher might claim to have trained a “gaydar model” that “can predict sexual orientation from faces.”
That’s overfitting (and researchers who do this are assholes).
Overfitting is a big problem in ML: if all the training pics of Republicans come from rallies in Phoenix, the model might decide that suntans are correlated with Republican politics – and then make bad guesses about the politics of subjects in photos from LA or Miami.
To combat overfitting, ML researchers sometimes inject noise into the training data, as an effort to break up these spurious correlations.
And that’s what Hoel thinks are brains are doing while we sleep: injecting noisy “training data” into our conceptions of the universe so we aren’t led astray by overgeneralization.
Overfitting is a real problem for people (another word for “overfitting” is “prejudice”)…
Sleeping, dreaming, and the importance of a nightly dose of irrationality– Corey Doctorow (@doctorow) explains: “Dreaming and overfitting,” from his ever-illuminating newsletter, Pluralistic. Eminently worthy of reading in full.
(Image above: Gontzal García del Caño, CC BY-NC-SA, modified)
* Shakespeare, Hamlet
###
As we nod off, we might send fully-oxygenated birthday greetings to Corneille Jean François Heymans; he was born on this date in 1892. A physiologist, he won the Nobel Prize for Physiology or Medicine in 1938 for showing how blood pressure and the oxygen content of the blood are measured by the body and transmitted to the brain via the nerves and not by the blood itself, as had previously been believed.
“Oxygen / Everything needs it”*…
As tongues of flame lapped the planet’s largest tract of rain forest over the past few weeks, it has rightfully inspired the world’s horror. The entire Amazon could be nearing the edge of a desiccating feedback loop, one that could end in catastrophic collapse. This collapse would threaten millions of species, from every branch of the tree of life, each of them—its idiosyncratic splendor, its subjective animal perception of the world—irretrievable once it’s gone. This arson has been tacitly encouraged by a Brazilian administration that is determined to develop the rain forest, over the objections of its indigenous inhabitants and the world at large. Losing the Amazon, beyond representing a planetary historic tragedy beyond measure, would also make meeting the ambitious climate goals of the Paris Agreement all but impossible. World leaders need to marshal all their political and diplomatic might to save it.
The Amazon is a vast, ineffable, vital, living wonder. It does not, however, supply the planet with 20 percent of its oxygen.
As the biochemist Nick Lane wrote in his 2003 book Oxygen, “Even the most foolhardy destruction of world forests could hardly dint our oxygen supply, though in other respects such short-sighted idiocy is an unspeakable tragedy.”…
There are very many very good reasons not to burn down the Amazon rain forest. Still, humans could burn every living thing on the planet and still not dent its oxygen supply: “The Amazon Is Not Earth’s Lungs.”
(Again– burning down the rainforest is bad, very very bad. But as long-time environmental reporter Michael Shellenberger argues, if we ground our concerns in the actual details of what’s happening, we’re much likelier to find effective responses.)
* Mary Oliver (from her collection Twist)
###
As we take a deep breath, we might recall that it was on this date in 1666 that the Great Fire of London broke out. The conflagration raged for four days, mostly in the City of London, within the old Roman walls; it did not spread to the aristocratic district of Westminster, to Charles II’s Palace of Whitehall, nor to most of the suburban slums. It destroyed 13,200 houses, St. Paul’s Cathedral, and 87 parish churches. Miraculously, fewer than 20 people lost their lives.
You must be logged in to post a comment.