The bacteria continue to grow exponentially only within tumors

Tuesday, February 18th, 2025

A University of Massachusetts Amherst-Ernest Pharmaceuticals team has developed a non-toxic bacterial therapy to deliver cancer-fighting drugs directly into tumors:

The team has been finetuning the development of non-toxic, genetically engineered strains of Salmonella to target tumors and then control the release of cancer-fighting drugs inside cancer cells. In addition to sparing healthy tissue from damage, this cancer treatment platform is able to deliver orders of magnitude more therapy than the administered dose because the simple-to-manufacture bacteria grow exponentially in tumors.

[…]

Early on in the research, the scientists discovered that it was the bacterial flagella – part of the cell that aids in movement – that enables the bacteria to invade cancer cells. So they engineered a genetic circuit in the bacteria that turns on the production of flagella with a simple, over-the-counter dose of aspirin. Without the turn-on switch provided by salicylic acid, the active metabolic product in the blood after a person takes an aspirin, the bacteria remain dormant in the tumor.

“One core part of this technology is the controlled activation of flagella,” Raman explains. “And the other core part is once the bacteria go inside cancer cells, we engineered them with a suicide circuit. So they rupture on their own and deliver the therapy inside the cancer cell.”

In pre-clinical research with mouse models, the bacteria is injected intravenously. “It goes everywhere, but then the immune system rapidly clears the attenuated bacteria from healthy organ tissue within two days. The bacteria continue to grow exponentially only within tumors during that time. On the third day, we give an over-the-counter dose of aspirin to trigger the bacteria to invade the cancer cells and then deliver the therapy,” Raman says.

Why are female intellectuals crazy?

Saturday, February 15th, 2025

Emil Kirkegaard presents his speculative model of sex differences among people with extreme beliefs, which explains why female intellectuals are crazy:

Women are more centrist in their personality and thus their beliefs than men. They hold views that are more common, or statistically speaking, their standard deviation is smaller for beliefs and their strength of belief. This is just a special case of the nearly universal greater male variance finding.

To move a person to adopt views that are very unlike those held by the rest of society, some kind of psychological push-factor is needed. The main push-factors are intelligence, open-mindedness, or craziness (psychopathology, P factor).

Thus, statistically speaking, women with extreme views need a stronger push factor than men do to attain those views.

Thus, statistically speaking, women with extreme views will average higher open-mindedness, intelligence, and craziness.

5% is about the base rate for pandemic flus per year

Wednesday, February 5th, 2025

Flu, Scott Alexander reminds us, is a disease caused by a family of related influenza viruses:

Pandemic flu is always caused by the influenza A virus. Influenza A has two surface antigen proteins, hemagglutinin (18 flavors) and neuraminidase (11 flavors). A particular flu strain is named after which flavors of these two proteins it has – for example, H3N2, or H5N1.

Influenza A evolved in birds, and stayed there for at least thousands of years. It crossed to humans later, maybe during historic times – different sources give suggest dates as early as 500 BC or as late as 1500 AD. It probably crossed over multiple times. Maybe it died out in humans after some crossovers, stuck around in birds, and crossed over from birds to humans again later.

During historic times, the flu has followed a pattern of big pandemics once every few decades, plus small seasonal epidemics each winter. The big pandemics happen when a new strain of flu crosses from animals into humans. Then the new strain sticks around, undergoes normal gradual mutation, and once a year immune response decays enough / mutations accumulate enough to cause another small seasonal epidemic (Why is this synced to the calendar year? See here for more).

Let’s digress to visit his piece on “diseasonality”:

The most common theories for disease seasonality are:

  1. Pathogens like the cold
  2. Pathogens like low humidity
  3. People are cramped indoors during the winter
  4. People have low vitamin D during the winter, and vitamin D helps fight pathogens

None of these are really satisfactory on their own.

[…]

Deprived of seasons, a place doesn’t just have a slow burn of flu cases all year. It has a big epidemic, then dies down for a while, then has another big epidemic. In retrospect, this is an obvious consequence of how diseases work (eg the SIR model of transmission). Some people get the disease, it spreads exponentially until lots of people are immune, and then it stops until something changes.

[…]

So in the tropics, Florida, and Alaska, epidemics “want” to follow a cycle of coming approximately once a year. In the tropics, nothing is giving them that cycle, so they come at a random time once a year, or twice a year, or whatever. In Florida, UV light, temperature, etc provide that cycle, and they come once a year. In Alaska, UV light, temperature, etc also provide that cycle, and they come once a year independent of what’s going on in Florida.

Back to the original piece:

The severity of any given flu epidemic depends both on the innate severity of the virus, and on how closely the human population’s circulating flu antibodies match the epidemic strain. People usually have good antibodies to the seasonal flu, because it’s only slightly different from last year’s seasonal flu. For the big new animal crossovers, the level of protection provided by existing antibodies is unpredictable. Older people may have antibodies left over from the last time that particular flu crossed over from animals to humans; younger people probably won’t. In some cases, people’s immune systems will be permanently synced to the first flu they encounter, with less protection against subsequent versions.

So for example, the Spanish Flu of 1918 was an H1N1 strain that killed about 2% of the world population. But the exact mortality pattern was surprising; people between 18 and 28 were especially likely to die, and people older than 88 especially likely to survive. Why? Because an H1N1 flu went pandemic in 1830; anyone who first encountered the flu around then had an immune system synced to H1N1. But an H3N8 flu went pandemic between 1890 and 1900; anyone who first encountered the flu then had an immune system synced to that strain and was unprepared for H1N1.

[…]

Interestingly, 5% is about the base rate for pandemic flus per year: five in the past century = one per twenty years = 5% chance per year.

[…]

Third, maybe mortality would be between 0.01% and 0.2%. The argument here is looking at normal (ie not 1918) flu pandemics of the past century. The least bad among these, the 2009 swine flu, had CFR of 0.01%. The worst, Hong Kong flu, was somewhere around 0.2%. If H5N1 is a normal pandemic flu — and right now there’s not much that differentiates it — it will probably be somewhere in that range.

Fourth, maybe mortality will be 2-10%. This was the mortality rate of the 1918 Spanish Flu. It seems to be an outlier: as far as we know, no other flu in the past 500 years was nearly as bad.

Therapeutic plasma exchange (TPE) replaces a patient’s plasma with saline and purified albumin

Wednesday, January 29th, 2025

The deregulation of the immune system with age eventually leads to chronic inflammation, or inflammaging, but blood sharing between young and old mice has shown rapid and robust pro-geronic and rejuvenative influences:

Interestingly, the procedure of small animal plasma exchange to dilute the circulating factors in plasma effectively reset the age-elevated systemic proteome and restored youthful healthy maintenance and repair of muscle, liver, and brain, without any added young blood, young plasma, or young factors.

For people, plasma dilution is known as plasmapheresis or therapeutic plasma exchange (TPE); it replaces a patient’s plasma with saline and purified albumin. The blood cells are returned to the patient so that while the cell profile does not change, the circulating blood proteins are diluted, including cytokines, autoreactive antibodies or toxins, and such pathogenic determinants of specific disorders.

Although its full therapeutic benefits are still being discovered, TPE is one of the treatments for autoimmune and neurological diseases such as myasthenia gravis, Alzheimer’s disease, and Guillain–Barre syndrome.

Moreover, TPE has the capacity to relieve the symptoms of long-haul COVID-19, including prevention of pneumonia, reduction of “brain fog,” and attenuation of the cytokine storm and hyper-inflammation.

This came up when eccentric life-extension fanatic Bryan Johnson (“Don’t die!”) shared the news — accompanied by a delightful photo — that he;s no longer injecting his son’s blood:

 

Pilot studies of TPE involving mice and three human patients look promising:

The results demonstrate significant and lasting rejuvenation of both humoral and cellular blood compartments in people who underwent repeated plasmapheresis. The rejuvenative changes are not limited to a reduction of inflammaging but encompass diminished circulatory protein markers of neurodegeneration and cancer, as well as reduced senescence, lower DNA damage, and improved myeloid/lymphoid homeostasis. Mechanistically, these and previously reported positive effects of TPE become better understood through longitudinal comparative proteomics of the blood plasma, demonstrating a youthful recalibration of the canonical signaling pathways, broadly regulating tissue health, and interacting through the node of TPR-4. Lastly, a novel application of Levene’s test to profile the noise of the systemic proteome uncovered several proteins: new biomarkers that collectively quantify a person’s biological age, removing a need for predictions.

Former CIA director William Burns had told analysts that they needed to take a position on the origins of the Covid-19 pandemic, but that he was agnostic on potential theories

Sunday, January 26th, 2025

The Central Intelligence Agency said Saturday that it’s more likely a lab leak caused the Covid-19 pandemic than an infected animal that spread the virus to people, changing the agency’s yearslong stance that it couldn’t conclude with certainty where the pandemic started:

The agency made its new assessment public two days after former Republican lawmaker John Ratcliffe was sworn in as its new leader.

“We have low confidence in this judgement and will continue to evaluate any available credible new intelligence reporting or open-source information that could change CIA’s assessment,” an unnamed CIA spokesperson wrote in an email sent to reporters Saturday.

The statement didn’t include any additional details about what led the agency to change its assessment and whether it had intelligence that would add weight to the theory that the virus had leaked from a research lab in Wuhan, China.

A U.S. official granted anonymity to share private details about the assessment said former CIA director William Burns had told analysts that they needed to take a position on the origins of the Covid-19 pandemic, but that he was agnostic on potential theories.

A new CIA analysis of the intelligence it had on the virus’ origin was completed and published internally before Ratcliffe’s arrival, the U.S. official said. Ratcliffe authorized its public release, the official added.

It’s similar to chainmail in that it cannot easily rip, because each of the mechanical bonds has a bit of freedom to slide around

Tuesday, January 21st, 2025

For decades, chemists have known how to interlock individual molecular rings, or small groups of them, but a reliable way to interlock large groups of these rings into strings and sheets had so far eluded them:

Researchers led by William Dichtel, a chemist at Northwestern University, have now done just that. They started by coaxing myriad copies of X-shaped molecules to settle into a crystal, so that they lined up in two interpenetrating sheets: In one direction the tips of each molecular X nearly touched those adjacent to it, like XXXXXXX. The same pattern repeated in a perpendicular direction, creating an interlocking fishnet. But these links were held together by weak hydrogen bonds, which meant the meshed material could easily come apart. So, Dichtel and his colleagues added a silicon-based compound that inserted itself at the tips of each pair of Xs, strengthening these attachment points with tougher, more durable covalent bonds and producing a polymer composed of interlocking rings, each of which serves as “mechanical” bond further strengthening the material.

The result, Dichtel and his colleagues report, is strong sheets of interlocking rings. “It’s similar to chainmail in that it cannot easily rip because each of the mechanical bonds has a bit of freedom to slide around,” he says. “If you pull it, it can dissipate the applied force in multiple directions. And if you want to rip it apart, you have to break it in many, many different places.”

When a team of collaborators led by Matthew Becker at Duke University wove just 2.5% of this new material into Ultem—a material made of high-strength fibers in the same family as Kevlar, the resulting fabric’s stiffness increased by nearly 50%. It’s still early days, but “almost every property we have measured has been exceptional in some way,” Dichtel says.

Darwin and Wallace were not just Victorian naturalists who traveled the tropics

Saturday, January 4th, 2025

Growth of Biological Thought by Ernst MayrMidway through his 900 page history of biology, The Growth of Biological Thought, zoologist Ernst Mayr notes that Alfred Wallace independently developed a theory of speciation by means of natural selection after Darwin had been sitting on his evolutionary theory for two decades:

Reading Wallace’s 1858 paper “On the Tendency of Species to Form Varieties” spooked Darwin. He did not want to be scooped. Within a year Darwin had rushed his material into an “abstract which… must necessarily be imperfect” as it only gave “the general conclusions” of his theory, and offered only a “few facts in illustration” to support them. We know this abstract well: it was published as The Origin of Species.

[…]

[Mayr] suggests that Darwin and Wallace were not just Victorian naturalists who traveled the tropics — they were Victorian naturalists who traveled the tropics with a copy of Charles Lyell’s Principles of Geology in hand.

Charles Lyell was an essentialist and a creationist. He answered questions like “what are the causes for the extinction of species?” and “how did the specific species we see in the fossil record arise?” in an explicitly essentialist and creationist fashion. These answers were not sound—but the questions were. These questions “were encountered by Darwin when he read the Principles of Geology during and after the voyage of the Beagle. As a result of Lyell’s writings, these questions became the center of Darwin’s research program.” This was all true for Wallace as well.

Mayr argues that the “Lyell-Darwin relationship illustrates in an almost textbook-like fashion a frequently occurring relationship among scientists.” This is not quite the relationship between pupil and teacher, or that of the “forerunner,” but something else. It is the relationship between the question-poser and the answer-finder.

Tanner Greer sees examples of the same dynamic in history and social science often:
Grand Strategy of the Roman Empire by Edward N. Luttwak

To pick one example, Edward Luttwak’s book Grand Strategy of the Roman Empire is wrong in every one of its essential arguments. So conclusively wrong is this book that I do not think it should be included on any syllabus. Since Luttwak published that book in 1976, a dozen studies of Roman frontier deployments, Roman strategic culture, and Roman decision making have been published. All offer a steady refutation of Luttwak’s work. However, not one of those books or articles would have been written without Luttwak’s work. Luttwak was wrong in every particular except the questions he asked—but those questions were good enough to create an entire subfield of research. May all our errors do such good!

Today the prediction is at 20%

Wednesday, January 1st, 2025

Alex Tabarrok remains stunned at how poorly we are responding to the threat from H5N1:

Our poor response to COVID was regrettable but perhaps understandable given the US hadn’t faced a major pandemic in decades. Having been through COVID, however, you would think that we would be primed. But no. Instead of acting aggressively to stop the spread in cows we took a gamble that avian flu would fizzle out. It didn’t.

[…]

The case fatality rate for cows appears to be low but significant, perhaps 2%. A small number of pigs have also been infected. On the other hand, over 100 million chickens, turkeys and ducks have been killed or culled.

There have now been 66 cases in humans in the US. Moreover, the CDC reports that in at least one case the virus appears to have evolved within its human host to become more infectious. We don’t know that for sure but it’s not good news. Recall that in theory a single mutation will make the virus much more capable of infecting humans.

When I wrote on December 1 that A Bird Flu Pandemic Would Be One of the Most Foreseeable Catastrophes in History, Manifold Markets was predicting a 9% probability of greater than 1 million US human cases in 2025. Today the prediction is at 20%.

What really happened in Wuhan

Tuesday, December 31st, 2024

Matt Ridley looks back at what really happened in Wuhan five years ago:

At one minute to midnight, US East Coast time, on the last day of 2019, there was a brief ‘request for information’ on ProMED-mail, an online newsletter that monitors unofficial sources to gather intelligence about new disease outbreaks affecting people and animals. It read, simply: ‘Undiagnosed pneumonia: China (Hubei).’

Dr Marjorie Pollack, the deputy editor of ProMED-mail, had been alerted by a Taiwanese colleague to a message on WeChat, the Chinese social-media site, sent by an ophthalmologist in Wuhan named Dr Li Wenliang: ‘Seven cases of SARS have been diagnosed at the Huanan Fruit and Seafood Market, quarantined in our hospital’s emergency department.’

Li had learned of this from a colleague, Dr Ai Fen, the director of the emergency department of the Wuhan Central Hospital, who had sent samples from her latest pneumonia patient for testing. The results came back on the afternoon of 30 December: ‘SARS coronavirus’, a shocking diagnosis not seen in China for 15 years. Ai circled the word ‘SARS’, photographed it and copied it to a friend at a different hospital.

Dr ‘George’ Fu Gao, the head of the Chinese Centre for Disease Control in Beijing, saw the WeChat message. Just a few weeks before, he had made a rather bold claim: ‘SARS-like viruses can appear at any time. However, I am very confident to say that “SARS-like events” will not occur again, because the infectious-disease surveillance network system of our country is well established, and such events will not happen again.’

So Gao was especially alarmed to hear about an outbreak of a SARS-like virus not through the official surveillance network, but through social media. He raised the alarm with China’s health minister. Liang Wannian, head of the National Health Commission, was despatched to Wuhan on 31 December. Immediately on arrival he took the decision to close down the Huanan Seafood Market, despite the fact that Ai’s latest patient had no connection to the market.

The local officials were already acting fast – but not to stop the disease, only to stop the news of it spreading. Within hours of his WeChat post, at 1.30am on 31 December, Li Wenliang was summoned to an interrogation by the Wuhan Municipal Health Commission. He was made to wait until 4am before being interviewed and forced to sign a humiliating confession of sharing ‘untruthful information’. Six weeks later, he would die of Covid.

[…]

Shi Zhengli, head of the Centre for Emerging Infectious Diseases at the Wuhan Institute of Virology, was at a conference in Shanghai. On 30 December she was ordered by the head of the WIV to drop whatever she was doing, abandon the conference and catch a train back to the lab to examine samples that had been sent there from the hospital.

I wondered if [the municipal health authority] got it wrong’, she later told a journalist. ‘I had never expected this kind of thing to happen in Wuhan, in central China.’ She then recalls worrying: ‘Could they [the viruses] have come from our lab?’

Well might she worry. In the preceding 20 years, her lab had been responsible for tracking down the source of the SARS outbreak of 2003. To do this, they had sampled animals and people from all over China, zeroing in on horseshoe bats in southern Yunnan near the border with Laos, from where thousands of bat faeces and blood samples had been sent a thousand miles north to Wuhan. Her lab contained more SARS-like viruses in its freezers than the rest of the world put together: none came from Wuhan itself. These included the closest known relative of what would soon be called SARS-CoV-2. Quite a coincidence.

But it was worse than that. Shi had supervised a team, led by Ben Hu, to do a series of experiments with these bat viruses, swapping their spike genes between strains, infecting human cells with them and infecting mice with human genes. In one experiment, the virus had gained a 10,000-fold increase in infectivity. Some of these experiments had been done at inappropriately low biosafety levels. The risk of a scientist falling ill with a human-trained version of a SARS-like virus was high.

Still more worryingly, the previous year Shi had worked on a plan to insert a feature called a furin cleavage site, known to increase infectivity in human beings but not bats, into a SARS-like virus for the first time. SARS-CoV-2 is still today the only SARS-like virus known with a furin cleavage site.

[…]

The authorities excluded from testing all potential cases that had no connection or proximity to the seafood market. They insisted the virus could only be caught from animals, despite nurses and doctors falling sick. They went ahead with a huge banquet for the Chinese New Year and encouraged people to travel abroad. By mid January at the latest, the virus was already in a dozen countries, every index case tracing back to a traveller from Wuhan.

When tapped, lead crystal makes a ringing sound

Wednesday, December 25th, 2024

When I was a kid, we would get out the fine china and the the lead crystal for holidays like Thanksgiving and Christmas, and both names struck me as odd, because nothing about the nice plates seemed Chinese, and the nice glasses were obviously glass, not lead. Fine porcelain of course did come from China originally, and lead crystal does contain lead, even if that’s obviously a bad idea:

Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% (by mass) lead(II) oxide (PbO), while modern lead crystal, historically also known as flint glass due to the original silica source, contains a minimum of 24% PbO. Lead glass is often desirable for a variety of uses due to its clarity. In marketing terms it is often called crystal glass.

The term lead crystal is, technically, not an accurate term to describe lead glass, because glass lacks a crystalline structure and is instead an amorphous solid. The use of the term remains popular for historical and commercial reasons, but is sometimes changed to simply crystal because of lead’s reputation as a toxic substance. It is retained from the Venetian word cristallo to describe the rock crystal (quartz) imitated by Murano glassmakers.

[…]

The addition of lead oxide to glass raises its refractive index and lowers its working temperature and viscosity. The attractive optical properties of lead glass result from the high content of the heavy metal lead. Lead also raises the density of the glass, being over 7 times as dense as calcium.

[…]

The brilliance of lead crystal relies on the high refractive index caused by the lead content. Ordinary glass has a refractive (n) of 1.5, while the addition of lead produces a range up to 1.7[1] or 1.8.[6] This heightened refractive index also correlates with increased dispersion, which measures the degree to which a medium separates light into its component wavelengths, thus producing a spectrum, just as a prism does. Crystal cutting techniques exploit these properties to create a brilliant, sparkling effect as each cut facet in cut glass reflects and transmits light through the object.

[…]

When tapped, lead crystal makes a ringing sound, unlike ordinary glasses. The wine glasses were always valued also for their “ring” made by the clinking glasses. The sound was better when large quantity of the lead oxide was present in the glassmaking material, like in the British and Irish wine glasses of the 17th-19th centuries with their “rich bell-notes of F and G sharp”.

[…]

George Ravenscroft (1618–1681) was the first to produce clear lead crystal glassware on an industrial scale. The son of a merchant with close ties to Venice, Ravenscroft had the cultural and financial resources necessary to revolutionise the glass trade, setting the basis from which England overtook Venice and Bohemia as the centre of the glass industry in the eighteenth and nineteenth centuries.

[…]

The amount of lead released from lead glass increases with the acidity of the substance being served. Vinegar, for example, has been shown to cause more rapid leaching compared to white wine, as vinegar is more acidic. Citrus juices and other acidic drinks leach lead from crystal as effectively as alcoholic beverages. Daily usage of lead crystalware (without longer-term storage) was found to add up to 14.5 ?g of lead from drinking a 350ml cola beverage.

The amount of lead released into a food or drink increases with the amount of time it stays in the vessel. In a study performed at North Carolina State University, the amount of lead migration was measured for port wine stored in lead crystal decanters. After two days, lead levels were 89 ?g/L (micrograms per liter). After four months, lead levels were between 2,000 and 5,000 ?g/L. White wine doubled its lead content within an hour of storage and tripled it within four hours. Some brandy stored in lead crystal for over five years had lead levels around 20,000 ?g/L.

[…]

It has been proposed that the historic association of gout with the upper classes in Europe and America was, in part, caused by the extensive use of lead crystal decanters to store fortified wines and whisky.

5.6 trillion metric tons of hydrogen may be buried below Earth’s surface

Tuesday, December 24th, 2024

A recent study led by a petroleum geochemist at the U.S. Geological Survey suggests that 5.6 trillion metric tons of hydrogen gas could be buried beneath the Earth’s surface in rocks and underground reservoirs:

The study published in Science Advances predicts a wide range of values for the potential in-place hydrogen resource (103 to 1010 million metric tons (Mt)) with the most probable value of ~5.6 × 106 Mt. Although most of this hydrogen is likely to be impractical to recover, a small fraction or two percent (e.g., 1 × 105 Mt) would supply the projected hydrogen needed to reach net-zero carbon emissions for ~200 years.

This amount of hydrogen contains more energy (~1.4 × 1016 MJ) than all proven natural gas reserves on Earth (~8.4 × 1015 MJ).

HPH-15 outperforms metformin by activating AMP-activated protein kinase (AMPK)

Saturday, December 21st, 2024

A research team at Kumamoto University, led by Visiting Associate Professor Hiroshi Tateishi and Professor Eiichi Araki, has identified HPH-15 as a promising alternative to existing diabetes medications like metformin:

The study, published in Diabetologia, a top journal in the field of diabetes, demonstrates that HPH-15 outperforms metformin by activating AMP-activated protein kinase (AMPK) — a critical protein regulating energy balance — at lower doses. HPH-15 not only improved glucose uptake in liver, muscle, and fat cells but also significantly reduced fat accumulation in high-fat diet (HFD)-induced obese mice. Unlike metformin, HPH-15 exhibited additional antifibrotic properties, potentially addressing liver fibrosis and other complications often seen in diabetes patients.

Cold-weather exercise relies on a different fuel mix

Friday, December 20th, 2024

Sports scientists have been obsessed with the benefits of heat training, Alex Hutchinson notes:

The extra stress of heat triggers various adaptations that help you handle hot conditions, like more sweating. Some of these adaptations, like increased blood volume, may even give you a boost when competing in cooler conditions. As a result, many top athletes now incorporate elaborate heat protocols into their training.

Dominique Gagnon‘s research suggests that cold training has its own advantages:

Back in 2013, for example, he published data showing that cold-weather exercise relies on a different fuel mix than warmer conditions, burning more fat and less carbohydrate.

[…]

Human metabolism is only about 25 percent efficient — comparable to the internal combustion engine in your car — so three-quarters of the energy in your food is released as heat in the muscles. That means that the temperature inside your muscles can be high even when the rest of you is cool. The advantage of exercising in the cold, then, is that it prevents your muscle cells from overheating and enables them to keep burning more fat for aerobic energy, which relies on the mitochondria in your muscles. In the long run, that should boost mitochondria levels and train your body to become more efficient aerobically.

[…]

In Gagnon’s new study, 34 volunteers trained three times a week for seven weeks, doing interval workouts on an exercise bike. Before and after the training period, they had muscle biopsies, which involve removing a small chunk of muscle from the leg, in order to analyse how much mitochondria was present. Sure enough, the group that trained in 32-degree air [versus 77 degrees Fahrenheit] had a significantly greater increase in several different markers of mitochondrial content.

[…]

Stephen Cheung and his colleagues at Brock University in Canada showed that getting superficially cold, with no drop in core temperature, reduced time to exhaustion in a cycling test by about 30 percent. That involved sitting in a 32-degree room with a light breeze for half an hour before the subjects even started cycling. Staying in the room for longer, so that their core temperature actually dropped by a degree, reduced endurance by another 30 to 40 percent. This is not what Gagnon is aiming for.

California ground squirrels eat voles

Thursday, December 19th, 2024

In addition to seeds and nuts, California ground squirrels also eat voles:

“This was shocking,” said Jenn Smith, an ecologist at the University of Wisconsin-Eau Claire. “We had never seen this behavior before.”

For the study, scientists observed squirrels in a regional park near the San Francisco Bay and consistently saw the creatures hunting down voles. Such sightings, recorded in videos and photographs, coincided with a surge in vole numbers at the height of summer. The research, published in the Journal of Ethology, is the first to find a significant number of squirrels eating meat.

California ground squirrel eats vole by Sonja Wild

“I could barely believe my eyes,” said coauthor Sonja Wild, a postdoctoral researcher at UC Davis. “From then, we saw that behavior almost every day. Once we started looking, we saw it everywhere.”

All bacon is cured

Wednesday, December 4th, 2024

All bacon is cured, but some is labeled uncured:

“Curing is the addition of salt to a product to change the chemical properties in a way that preserves it,” says Moskowitz. The salt in the brine prevents the growth of certain kinds of bacteria that cause meat to spoil. Curing also imparts flavor to the meat. In addition to salt, often sugar, herbs, or spices are added to the brine for flavor.

Both cured and uncured bacon start as slabs of pork belly that are either injected with a wet brine — a saltwater solution — or placed into a wet brine. Some bacon is still made using a dry brine — a dry salt and seasoning mixture — but wet brines are more common.

Smoking meat is also a way of preserving it, and most bacon is smoked over a low temperature after being cured to help further dehydrate the meat, and to impart a nice smoky flavor.

Bacon is most often cured using artificial nitrites, a chemical additive that preserves the meat and gives bacon its pink color. The bacon at Foster Sundry is cured in-house using pink curing salt (it’s not the same thing as Himalayan pink salt), a mixture of sodium chloride (table salt) and sodium nitrite. Pink salt is also known as Prague powder, Insta Cure #1, or pink curing salt #1, and it is commonly used to cure meats, like corned beef.

“There’s a more attractive color on a cured product,” says Moskowitz, “especially when it’s been cured with pink salt.” That’s a large part of the reason butchers prefer cured bacon. When exposed to air, cured bacon maintains its pink color much longer than uncured bacon, which can quickly turn gray.

There isn’t such a thing as “uncured” when it comes to bacon. “It’s misleading,” says Moskowitz. “Most things that are labeled as uncured have had celery salt added to it.”

Celery salt, which contains naturally occurring nitrites, cures the bacon. Bacon labeled as uncured was cured without artificial nitrites like pink salt.

The USDA rules require uncured bacon to be labeled as “no nitrites or nitrates added.” Nitrites are naturally occurring both in our bodies as well as in many foods like celery, lettuce, spinach, and beets. Celery salt and sea salt are two natural nitrates often used to cure meat.