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Sydney Brenner: the last giants of 20th century biology

Losing one of the heroes of 20th century science

Sydney Brenner died yesterday. That's him on the right, standing next to James Watson at the Asilomar Conference, 1975. I don't want to write a proper eulogy, because they've been done (here's a good one). It'll do to say that he was a scientist of a stratospheric status. I sometimes thought about him when I was in grad school and kept being surprised that we were both working in science at the same time. It was like reminding myself that a myth wasn't myth at all but real flesh and blood, like someone casually remarking that there were dragons in the parking lot. He won a Nobel Prize in 2002, rightfully so, but it should've been his second. He was a fulcrum of 20th century biology, a peer of essentially every famous biologist of the '50s, like Rosalind Franklin and Watson and Crick. 

A lot of the focus from Brenner's career has been on his introducing Caenorhabditis elegans, a cute little flatworm into the biologist's repertoire. (It's okay, usually people just say "see el-uh-gans".) It should! He won a Nobel Prize for it. C. elegans was a great idea -- they're easy to work with, you can store them in the freezer (something you can't do with fruit flies or mice, other neuroscientist favorites), and they have a very low, very specific number of neurons -- 302. No more, no less. That makes them easy to study, easy to grow and maintain, and easy to learn on. If you walk into a C. elegans lab you might be lucky enough to see a scientist sitting at a microscope, plucking their own hairs off their arm or their eyebrows to use as hooks to pick up tiny worms. This is absolutely true. 

It's astonishing to think about but Brenner should have already won a Nobel Prize by the time he actually got one for C. elegans. He was one of the last living members of the Phage Group, a collection of molecular biologists who used bacteriophages, viruses that infect bacteria, as models to discover the most basic fundamentals of genetics -- how DNA works, how proteins are made, and what the genetic code is. Earlier this week we published an article about Elisa Izaurralde, who worked out how messenger RNA (mRNA) gets distributed around the cell. Sydney Brenner invented the idea of mRNA more or less out of thin air. The idea is that mRNA acts as a temporary copy of the information encoded in DNA. A cell uses that copy to make a protein, instead of reading directly off of DNA. In the early 1960s there...wasn't much in the way of concrete evidence to support this idea. Brenner (and a few others, including Francis Crick) knew at the time that there was DNA, and there was protein, but there was something in the middle that was missing. They stuck RNA in the middle. Just like that. 

*The Eighth Day of Creation: The Makers of the Revolution in Biology - Horace Freeland Judson

Genomics has a diversity problem. Here's how scientists are tackling it

At ASHG, researchers are seeing that using only data from white Europeans is leading to incorrect conclusions

Farah Qaiser

Molecular Genetics

University of Toronto

This week, over 8,300 researchers, exhibitors, and journalists arrived in Houston to attend the 2019 American Society of Human Genetics’ (ASHG) Annual Meeting to learn more about cutting edge research in the field of human genetics and genomics. Interestingly, one issue kept popping up throughout the ASHG meeting: the lack of diversity in human genomics research.

This isn’t a new issue. 

The human reference genome — the sequence to which all DNA is mapped in reference to — is largely based on individuals of European descent, making it difficult for individuals from under-represented groups to benefit from current progress in genomics. In fact, 70% of the human reference sequence actually originates from a single individual. While this reference genome has helped pushed the field forward, it doesn’t accurately represent our global genomic landscape. 

Researchers are aware of this issue — and here’s how they’re tackling diversity in genomics research.

One remarkable effort is being carried out by the Human Hereditary and Health in Africa (H3Africa) consortium, which was launched in 2013 to address the under-representation of African individuals in genomics. H3Africa, with support from the National Institutes of Health, sequenced the entire genome of 426 individuals from 13 different countries, providing a more complete picture of Africa’s genomic diversity.

In the opening ASHG plenary session, Neil Hanchard, assistant professor at the Baylor College of Medicine, shared that this large-scale sequencing effort identified over three million novel single nucleotide variants — which have not yet been observed in current (largely European) genomic databases. For example, surveyed populations from Mali and Botswana had at least 6,000 novel common variants. This concept of "rare" and "common" variants is particularly important since how frequent a variant is in a population is often used to infer pathogenicity (i.e. how damaging it is). The H3Africa consortia’s initial findings show that some previously classified pathogenic variants are in fact not rare and are found in variable frequencies across African genomes.

“This is a starting point,” said Hanchard at the plenary meeting. “African genomes have the potential to inform the [genomics] field more globally.”

In a similar vein, a group of US researchers sequenced over 300 genomes from around the world, including both male and female individuals from different sub populations. By looking at breakpoints and sequence content, the researchers were able to use a technique called de novo assembly to align unique sequences (which previously could not be mapped) to the reference genome, thus constructing a more representative, and detailed, reference genome.

In addition to ongoing efforts like the ambitious All of Us program, these efforts can together help us move towards a future where people everywhere — regardless of their geographic location or ethnicity - will all be able to reap the benefits of human genomics research. 

The Convention for the Conservation of Antarctic Marine Living Resources is unique among international environmental agreements

But that doesn't mean that it's perfect — getting nations to agree requires both formal and informal negotiations

Seth Sykora-Bodie

Conservation ecology

Duke University and CNRS Paris

The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) entered into force in 1982, with the express purpose of ensuring “the conservation of Antarctic marine living resources.” This focus on conservation was revolutionary because  other similar international environmental agreements took single-species approaches to regulating fisheries, whereas CCAMLR took an ecosystem-based approach to preserving the Southern Ocean as a whole. In its opening lines, the convention insisted on the “importance of safeguarding the environment and protecting the integrity of the ecosystem of the seas surrounding Antarctica.”

While the text of the convention endorses taking an ecosystem-based approach to protecting Antarctic marine living resources, implementing these principles has been a more gradual process. Initially, CCAMLR focused its attention on immediate concerns such as managing krill fisheries and then in the 1990s on reducing illegal, unreported, and unregulated fishing within the Antarctic. In the last two decades, however, CCAMLR members have sought to more fully implement the holistic management principles articulated in the early 1980s by establishing a representative network of marine protected areas (MPAs), with two major successes: the designation of the South Orkney Islands Southern Shelf and the Ross Sea Region MPAs.

Despite these successes, other threats remain. In particular, some member countries have sought to advance their own agenda and engage in unrestricted fishing by reinterpreting the Convention and downplaying its roots as a conservation instrument. While the Convention’s definition of ‘conservation’ does include ‘rational use,’ it so strongly lays out the limited circumstances under which fishing may take place that this further highlights the intent of the original architects of the agreement, who intended for it to be a conservation-oriented instrument consistent with the principles of the Antarctic Treaty System. These efforts to undermine the convention have not gone unnoticed, and other parties have pushed back to ensure that CCAMLR remains able to protect the Southern Ocean ecosystem. 

Hammering out international environmental agreements and keeping them up to date is no easy task, and one that I explain more in a new paper, published in Aquatic Conservation. It examines the process of reaching consensus on proposed conservation measures to better understand the role of informal and external drivers in establishing large-scale networks of MPAs. Based on these insights, I also outline a series of recommendations for transboundary conservation efforts, which are likely to become increasingly more important as we tackle climate change and other large environmental issues.  

Vaccine-laced snacks are being scattered in the wilderness to protect wildlife from rabies

700,000 oral rabies vaccine baits are being distributed in southwest Virginia this fall

Alice Theibault

Environmental Science and Biotechnology

Rochester Institute of Technology

While rabies is relatively rare in humans in the United States, it's much more common in wildlife like raccoons, skunks, and bats. In fact, rabid raccoons have been identified in every state along the Atlantic coast. Since no wild raccoon wants to be trapped and stuck with a needle, the vaccines are instead put into baits, which the raccoons find and eat. Now, scientists and wildlife managers in Virginia are distributing a vaccine for raccoons that could prevent them from getting rabies. These baits have been used in the United States in one form or another since the 1990’s in foxes and coyotes as well as raccoons — but the project only recently came to southwest Virginia. 

U.S. Department of Agriculture

Although rabid animals are found across the country, so far raccoon rabies is limited to the Eastern Seaboard, and wildlife managers are hoping to use these vaccines to make sure it stays that way. Rabies is a pretty scary disease, so limiting its spread is extremely important. Symptoms, which may not develop for weeks or months after a bite from an infected animal, start off seeming like the flu — a fever, chills, muscle weakness, a headache — but quickly get much worse. The rabies virus attacks the brain and nervous system, and as the disease progresses patients may have anxiety, confusion, psychotic symptoms, a fear of water, and sometimes paralysis before they fall into a coma and die.

Most residents of first-world nations with advanced medical systems rarely worry about rabies because vaccines are readily available for both them and their pets. However, rabies remains a significant threat worldwide, particularly in rural areas of the Global South. Every year more than 59,000 people die from rabies, about half of whom are children under the age of fifteen. Globally, 99 percent of human cases are caused by contact with rabid dogs. Although they have not yet been widely implemented, studies on similar vaccinated baits have shown promise in combating rabies in dogs and thus in reducing risk to humans.

Meet the friendly vampire bat: they drink blood, cuddle and even groom fellow bats

Researchers tried to understand what motivates vampire bats to do nice things, like grooming each other

Donna McDermott

Ecology

Emory University

Vampire bats (Desmodus rotundus) do drink blood, which can be off-putting. However, vampire bats are also very cuddly, at least with one another. Female bats cluster together for warmth, share food, and groom their cuddle-mates by licking each other’s fur. Being groomed can reduce stress, lower heart rate, and promote cooperation.

It’s clear that bats benefit from being groomed, but not why others volunteer to be the groomer. Bat grooming often prompts animal behavior researchers to ask: why do animals do nice things, like grooming?

To study when bats are willing to groom one another, researchers at the Smithsonian Tropical Research Institute set up two tests for a colony of female vampire bat. In the first test, scientists rubbed water on the fur of each bats’ back, and then measured the amount of time each wet bat spent being groomed by other bats. 

As expected, bats were groomed more after getting wet. So, it appears that vampire bats will help out a friend in need. However, the second test showed that groomers weren’t only motivated by helping one another.

vampire bat flying, wings can be seen

A vampire bat in action.

By Uwe Schmidt

In the second test, scientists grouped a few female bats in clear cages for 30 minutes at a time, watching for each moment when one bat groomed another. The scientists noted what was happening just before each grooming event to measure how often the bats were grooming themselves before leaning over to spare a lick for a friend. 

The researchers found that one bat is most likely to groom another if the groomer has just been grooming herself. In short, some bats agree to groom others just because they like to lick. Perhaps the act of grooming reduces anxiety, just as being groomed does.

Studying the details of how animals cooperate is useful for understanding how social groups stay together in nature. For vampire bats, grooming isn’t all about utilitarianism or the fear of punishment. Sometimes, bats groom because they want to.    

A catastrophic power outage darkens California while horny spiders invade

Tarantulas, fire-inducing weather, and failing infrastructure make for a spooky October story

Cassie Freund

Ecology

Wake Forest University

I saw a tweet the other day that sent chills up my spine. 

I'm a field biologist, so I've spent plenty of time in the company of creepy crawlies, and I wouldn't call myself an arachnophobe, but something about sitting in a room where the lights have been shut off to prevent massive fires driven by a climate change-induced drought surrounded by migrating tarantulas sounds like my "The Day After Tomorrow" nightmare.

The mass tarantula migration is actually the least worrisome part of this story. Male tarantulas across the western part of the United States are migrating right now in search of mates. Tarantulas, with their huge, hairy bodies, look intimidating, but actually are not dangerous to humans. They have intricate courtship rituals that occasionally end up with the male as a meal instead of just a mate. And although this year's migration is slightly larger than it usually is, this is a normal phenomenon that happens from about mid-August to mid-October each year. Even if you (understandably) don't want to share your space with these eight-legged furballs, experts say that if you spot one you should just leave it alone


But something much more frightening than migrating tarantulas is happening in California at the same time. Pacific Gas and Electric Co. (PG&E), the main power company for much of the heavily-populated Bay Area, has shut off power to 800,000 customers in the region in the face of a red-flag wildfire and wind warning. High winds and increasingly dry weather caused by climate change mean that the entire area is — again — at risk of going up in flames. 

And this lack of preparation is, on some level, just a combination of greed, incompetence, and willful disregard for the environment. PG&E was found responsible for last year's deadly Camp Fire in Paradise, California, after faulty power lines sparked the blaze. And in April, the company was admonished by a judge for paying out shareholder dividends instead of trimming trees around dangerous lines. Now a large portion of California residents are paying the price as they spend unknown amounts of time in darkness.

U.S. infrastructure is simply not prepared for climate change. Hundreds of thousands in California are now reaping the whirlwind of that inaction. PG&E's sloth and ignorance put people, particularly those that rely on electricity for medical devices, in grave danger. There's many horrifying aspects of this story, but the one that stands out to me is that the only backup plan for people who need power for life sustaining medical equipment is for them to call an ambulance (presumably on their own dime).

As many have said time and time again, the most vulnerable among us will be the first to experience — and are already experiencing — the impacts of climate change. People are going to suffer and die, and it won't just happen in huge dramatic ways like hurricanes and drought. It'll happen in lots of mundane, insidious, and unnecessary ways. Like not having access to electricity to power a breathing machine, or not having an air conditioner during a heat wave. 

So by comparison I'm fine with the tarantulas.  

Fact check: Those red blobs aren’t oxytocin

An amazing image has been making the rounds on social media, but the researcher who created it has set the record straight on what it shows

David Baranger

Neuroscience

University of Pittsburgh

In 2015 MIT cognitive neuroscientist Dr. Rebecca Saxe took a magnetic resonance image (MRI) of herself kissing her son, the first of its kind in the world. Writing about the experience for Smithsonian Magazine, Dr. Saxe said that she and her collaborators took the image “because we wanted to see it.” This arresting image, the MRI Mother and Child [you can see it at the Smithsonian link above], is both extremely modern, captured with cutting edge technology, and timeless in its imagery. 

Now, four years later, a version of the image with red blobs lighting up the brains of both the Mother and Child, has gone viral again. Some posts about the image falsely conclude that the bright colors reflect the biology of the parent-child bond, mainly the release of  hormones like oxytocin (the so-called ‘love’ hormone). Recently, Dr.  Saxe took to Twitter to set the record straight. 

The ‘blobs’ in the image aren’t hormonal at all, but are results from a scientific study on how infant brains process visual information conducted by Dr. Saxe herself. The colors on the image reflect parts of the brain that used more oxygen (in that actual infant and mother) while viewing faces compared to oxygen use in brains viewing natural scenes. In fact, there isn’t yet any way to directly measure the release of oxytocin or its levels in the brains of living humans. The closest we can come is to measure its levels in blood or saliva, or to measure how brain activity changes when we give someone oxytocin. Developing methods to measure oxytocin in human brains is an area of active research, but it will probably be many years until we’ll be able to use them to study infants.  

You should wash your rice to reduce heavy metal contamination

Yes, washing rice involves sacrificing some of its nutritional value, but it also reduces the level of heavy metals present

Farah Qaiser

Molecular Genetics

University of Toronto

Have you ever wondered why you wash your rice  — or soak it overnight — before cooking it? Perhaps you wash your rice grains to enhance taste, reduce starch levels, or maybe that's just the way your family has always prepped rice. Thanks to a tip from science communicator Samantha Yammine — who came across Dr. Nausheen Sadiq's neat finding while live-tweeting a forum on Diversity and Excellence in Science — it turns out there is another reason why, as washing rice actually helps reduce the concentration of heavy metals, like chromium, cadmium, arsenic, and lead. 

Heavy metal contamination in crops can be caused by human activities, such as mining, fertilizers, pesticides, and sewage sludge. Compared to most cereal crops though, rice (Oryza sativa L.) actually accumulates more heavy materials, like cadmium or arsenic, where long-term heavy metal intake can cause health risks. For example, long-term arsenic exposure leads to skin disease, high blood pressure, and neurological effects. This is especially important to consider as rice is a staple food across the globe.

Brown rice being filtered by farmer

Heavy metal contamination in crops can be caused by human activities, such as mining, fertilizers, pesticides, and sewage sludge.

Photo by TUAN ANH TRAN on Unsplash 

In a recent study, researchers investigated the effects of different cooking methods (normal, high-pressure and microwave cooking) on the concentration, bio-accessibility and health risks posed by three heavy metals (cadmium, arsenic and lead) in two strains of brown rice. After cooking 100 grams of brown rice grains, researchers evaluated bioaccessibility (i.e. how much of the heavy metal is released for absorption) by mixing rice samples with simulated gastric fluid, and then used spectrometery to measure heavy metal concentration. Lastly, the researchers calculated the health risk posed by the heavy metals by calculating values such as the average daily dose.

Overall, the researchers found that instead of the three different cooking methods, it was the washing process which significantly reduced concentrations of cadmium, arsenic and lead, suggesting that the reduction may be due to rice morphology. For example, lead is found largely in the outer compartments of rice kernels, so lead is more likely to be removed during rice washing. 

In contrast, the three cooking methods did impact bioaccessibility i.e. how much of the heavy metal would be released for absorption by the body. Here, washing and soaking isn't enough as rice absorbs water poorly at 25°C. This finding was also reflected in calculated values: the average daily doses of cadmium, arsenic and lead were lower in washed and cooked rice, compared to raw rice.

It's worth noting that the European Commission has enforced limits on heavy metal levels - for example, arsenic is currently limited to 200 parts per billion (ppb) for adults and 100 ppb for infants. Both the U.S. and Canada currently have no limits in place for arsenic in food — though Canada is currently reviewing a proposal to add maximum levels for arsenic found in white and brown rice, while the U.S. FDA has previously released a (non-binding) risk assessment, suggesting the same 100 ppb levels as Europe.

So the takeaway here is that yes, your family and all those professional chefs have been right all along. Yes, washing rice involves sacrificing some of its nutritional value, but doing so means you can reduce the levels of heavy metals present in grains, and still enjoy dishes like rice cakes. And returning back to Yammine's reporting, Saudiq actually shared that by soaking and washing rice for ~5 mins, you can get rid of 50-100% of these elements. (Thanks Sam!)

Meet the colour-changing green forester moth: a living water vapour sensor

Researchers used microscopy techniques to understand how the green forester moth changes from a shiny green to a rusty red colour

Dori Grijseels

Neuroscience

University of Sussex

We often think of moths as boring and plain, especially in comparison to their more colorful siblings, the butterflies. However, moths can be just as colorful, and the green forester moth (Adscita statices), with its shiny green body and wings, is a great example of this. But this particular moth doesn’t always have its brilliant green colour. In fact, if you were to spot it early in the morning, it might have a rusty red color. It changes its color to green during the day and when night falls, the green forester moth will turn red again.

In a new study, researchers from the University of Fribourg and Lund University investigated this curious phenomenon. They used electron microscopy to look at what the tiny scales on the green forester's wings are made of, and a combination of microscopy techniques and optical modelling to figure out how the moth achieves this colour change. 

The researchers found that the moth wing scales contain a pigment which gives them their colour, like in many other insects. Interestingly, the green forester moth has two distinct types of scales: black ground scales, and coloured cover scales which have minuscule holes (50-300 nm wide) in the scales that can take up water. When these holes in the scales fill with water, it causes a distortion of the light and turns the moth from green to a rusty red. Because of this dynamic colour changing, the researchers have dubbed these moths ‘living water vapour sensors.’

The green forester moth next to a plant. Shared under a CC BY-SA 4.0 license (i.e. credit needed, free to adapt/re-use, including commercial purposes).

Charles James Sharp (Sharp Photography).

This ability allows the moths to be camouflaged in the morning and evening using the red colour in its native habitats, such as the reddish brown stems of meadow plants. On the other hand, the green colour both signals to birds that the moth is poisonous, and to potential mates that they are a good mate choice. However, it does come at a cost. The water vapour that gets trapped in the wings will make the moths heavier and will therefore make flying harder.

How exactly the moth evolved this humidity-dependent colour-changing ability  — despite it causing problems for flying  — is still an open question to be answered by the scientists. 

Scientists and journalists are furious at how PNAS promoted a recent study on female orgasms

What makes matters worse is that the study was done IN RABBITS!

Maddie Bender

Ecology & Evolutionary Biology

Yale University

A recent study in the journal PNAS injected rabbits with hormones to look at a potential link between the female orgasm and ovulation. The stock images (as seen below) used to promote the study had scientists and journalists up in arms on Twitter. 

PNAS tweet screenshot - female orgasm research done in rabbits

A screenshot of how PNAS used stock images to promote a recent study.

Twitter: @JNRutherford

I'll let the tweets speak for themselves: 







On 6th October (9:24 PM EST), the PNAS journal offered an apology and took down the offending tweets. 


Certain vaginal bacteria could help protect women from STIs

Some species of Lactobacillus appear to be protective against chlamydia

Sharon Casey

Clinical Research and Epidemiology

Harvard School of Dental Medicine

Reports of sexually transmitted infections (STIs) like chlamydia are on the rise. According to the Centers for Disease Control and Prevention (CDC), chlamydia is the most common notifiable disease in the U.S., and among the most prevalent of all STIs in the world.

STIs are a serious public health matter, and chlamydia in particular is associated with a host of devastating burdens to individuals and society as a whole. Patients with chlamydia often do not present clinical symptoms, a dangerous feature of this infection, as untreated cases of chlamydia can lead to serious health outcomes for young women, including pelvic inflammatory disease, ectopic pregnancy and infertility. It has been reported that this inflammatory condition may facilitate other infections such as HIV

Exactly how the cervicovaginal microbiome (the microbial community in an individual's cervix and vagina) might affect a woman's susceptibility to STIs is poorly understood. But, a type of bacteria called Lactobacillus are thought to play a protective role in the cervicovaginal environment. Researchers from the University of Maryland School of Medicine set out to understand the relationship between host and vaginal microbiome in an effort to identify how Lactobacillus might protect a woman from contracting chlamydia.

pipette with pink liquid

Photo by Louis Reed on Unsplash

They found that Lactobacillus species that produced a specific shape of lactic acid molecule (called an isomer, in this case called  D(−) lactic acid) were associated with protection against chlamydia and lower epithelial cell proliferation rates. One specific type of this bacteria, Lactobacillus iners, that did not produce D(-) lactic acid also provided little protection against chlamydia.

Our immune systems and microbiomes work hard to protect us from infection, and this paper is a great reminder of that. Further research is needed to improve our understanding of the role of the cervicovaginal microbiota in protection against STIs. This understanding could help us develop therapeutic strategies to minimize the burden of STIs and improve women’s health.

Out in the jungle, looking for a cave? Machine learning and lasers can help

New techniques are helping field researchers locate hard-to-spot caves

Gabriela Serrato Marks

Marine Geology

Massachusetts Institute of Technology

In densely vegetated tropical forests, caves can be incredibly difficult to find. The entrances are sometimes tiny, just big enough to squeeze into, or covered with branches and leaves. Even when you have exact GPS coordinates, caves that haven’t been visited in a while can blend into the rest of the environment. 

Leila Donn and other researchers walk past a rock wall, maybe near a cave.

Leila Donn (orange and blue gear) with other researchers walking past a cave wall.

Gabriela Serrato Marks

That means that it’s particularly difficult to find unmapped caves. Unfortunately, those undisturbed caves can also be the best places to find geological or archeological samples. That’s why Leila Donn, a graduate student at University of Texas - Austin, is trying to find a better way to search for caves. We first met last year, when we went caving in Belize. She’s a great caver because she is an accomplished rock climber, knowledgeable geologist, and pretty much completely fearless. I wasn’t at all surprised to hear that she had been finding caves in Belize that hadn’t been visited by humans for centuries. 

Although you may think that geologists just go out to the field with rock hammers and whack stuff, Donn’s work is extremely computational — she’s using machine learning to find the unmapped caves. Her approach combines LiDAR images (using lasers to create 3D maps) with other information about the terrain, like slope and distance to streams. Though the research hasn’t been peer reviewed yet, it has been tested (cave reviewed?): she successfully used the machine learning to find caves and sinkholes during a summer of ground-truthing. 

Stalactites and stalagmites in a cave.

Stalactites and stalagmites.

Gabriela Serrato Marks

Now that Donn knows her algorithm works, she’s going to add more training data and expand her analysis area. In the future, this research could be used to find more caves, but also to better manage wide swaths of forested areas. 

Rats love hide and seek

Studying play in animals could allow scientists to answer important questions about decision making, social behavior, and even theory of mind.

Anisha Kalidindi

Molecular Biology

Ohio State University

In general, neuroscientists consider anthropomorphizing animal behavior to be a faux pas. But increasing evidence indicates that many human behaviors can be observed in other animals, if only in a rudimentary form. Well-known to many people who keep rats as pets is their ability to play. Recently, researchers in Germany published a study on play behavior in rats, specifically the game hide-and-seek. This game may seem relatively simple, but requires complex behaviors including decision-making and perspective-taking. 


A pair of black and white rats

A pair of black and white rats

Jason Snyder on Wikimedia Commons

Fascinatingly, rats were able to learn to be both hiders and seekers. The game began when rats were placed in a box. If the box was open, the rats learned that this meant they were supposed to go and hide. The rats were able to strategize hiding location and showed a preference for an opaque box hiding place rather than a clear box. If the lid was initially closed, the rats learned that  this meant they had to go and find the experimenter. 

The experimenter would pet and tickle the rat at the end of the trial. In many tasks used in modern neuroscience, food is used as a reward, but in this study, the social interaction and the "fun" of the activity were enough to motivate the rats to learn this complex behavior. Further supporting this, the researcher saw that rats were having “fun” as evidenced by excitement behaviors such as freudensprung (“joy jumps”), and rats re-hiding after being found.

To understand underlying processes of this, electrical signals were recorded from the prefrontal cortex, a brain region involved in learning and social behavior. These recordings showed a subset of cells were activated during play and specifically when the box was closed (the game start cue). Scientists are still trying to figure out the implications of the neural activity that was recorded during these play activities. While we cannot see what the rats were thinking, this study does present important evidence of play behavior in rodents. Hide-and-seek is a complex game that allows for several aspects of the cognition to be studied (decision making, navigation, perspective taking). A task like this has lots of promise to be used to study the basis for animal behavior which could have potential implications in furthering our understanding of human behavior.

Graphene-based films shield human skin from mosquitoes

Scientists have exploited graphene and its derivatives for all kinds of applications ⁠— the latest is to ward off the pesky mosquito

Shi En Kim

Molecular Engineering and Materials Science

University of Chicago

Have you ever found yourself irritated by mosquitoes in a hot and humid climate, despite the insect repellent you've repeatedly slathered all over your body? If chemicals don’t work for you, then perhaps graphene-based clothing may help! 

Graphene is very unique as far as any material goes. Despite being only atomically thin, it is dense, electrically conductive, and 200 times stronger than steel. Scientists have exploited graphene and its derivatives (such as slightly oxidized graphene) for all kinds of applications; the latest yet is to ward off the pesky mosquito.

Researchers at Brown University exposed skin patches for five minute intervals to ~100 pathogen-free female Aedes aegypti mosquitoes (the bane of dengue fever, yellow fever, and Zika virus) and monitored their activity. The results showed that dry graphene oxide-covered skin never permitted a single mosquito bite, unlike the unprotected skin or cheesecloth-only controls, where bite numbers could range between five to 20. Fewer mosquitoes landed on protected skin, and even if they did, they never dawdled. From these observations, the researchers concluded that the graphene-based films masked the molecular signals mosquitoes needed to sense a live presence. Graphene’s impermeability essentially rendered human victims invisible to mosquitoes. 

When the researchers smeared the graphene-protected skin with human sweat or water, mosquito landings were much more frequent. However, this time, if graphene-based films became too wet, they swelled and became porous—and the underlying skin became vulnerable to mosquito bites. Here, only the excellent mechanical strength of reduced graphene-based films (i.e. with reduced oxygen functionality) barred mosquitoes from reaching the skin layer to take a bite, showing that using reduced graphene-based films in wearable technologies can provide mosquito bite protection in both dry and wet conditions.

Mosquitos biting a person's arm

A mosquito in action.

 CDC/ Prof. Frank Hadley Collins from the  Public Health Image Library

Perhaps mosquito-bite prevention by graphene-based materials is not a surprising result. These materials have already been used in water filtration, for encapsulation, and to lace plastics and metals as a means to enhance overall mechanical strength. Graphene wearables have also generated much buzz as graphene’s electrical conductivity allows for the design of ‘smart clothes’, whilst its mechanical strength enables the fabric to accommodate stresses generated by body movement

But to prevent mosquito bites is probably the most creative application yet. An overkill, perhaps? Nevertheless, it would be a tremendous relief to humans cohabiting with mosquitoes—we know how tenacious these pests can be.  

Step away from the immunosuppressant drugs — antibodies are on the case!

New research in mice suggests that using, not suppressing, the body's defenses against intruders is a promising avenue for treating autoimmune diseases

Sukalp Muzumdar

Molecular Biology

ETH Zurich

Autoimmune diseases are disorders where the body’s defense system turns on itself. This group of diseases, which includes rheumatoid arthritis and lupus, represents one of the top 10 causes of death in women. Automimmune diseases are currently primarily treated by immunosuppressive drugs which hold the immune system in check, but this type of therapy comes with the risk of developing severe infections and various other side effects.

Recently, a team of international researchers have found that distracting the body’s immune system by targeting its attention elsewhere could be an effective alternative to long-term immunosuppression with pharmaceuticals. They discovered that injecting antibodies against red blood cells into mice forced their immune systems to re-direct their efforts toward these specific cells, sparing other tissues from attack. They found that this approach was an effective treatment in various models of mouse arthritis, preventing the infiltration of inflammation-causing immune cells into the joints. 

Anti-red blood cell antibodies derived from healthy volunteers are in fact already being used to protect the rhesus positive (Rh+, referring to the plus or minus sign after your ABO blood group) babies of Rh- mothers, and such medications could be re-purposed to treat various other autoimmune diseases. This method of treating autoimmune diseases is promising in that it may decrease our reliance on immunosuppressant drugs someday down the line.

Captive sea otters (adorably) raise orphaned pups as their own until they are ready to be released back into the wild

New research from Monterey Bay Aquarium scientists finds that the pups and their own wild babies account for 55% of the growth of a California sea otter population

Cassie Freund

Ecology

Wake Forest University

Rescue and rehabilitation of stranded or injured wild animals is one tool at our disposal to protect endangered or threatened species, and in the U.S. it has helped conserve marine animals like the Hawaiian monk seal and Florida manatees. Zoos and aquariums substantially contribute to these efforts. New research out of the Monterey Bay Aquarium, published in the journal Oryx, highlights just how important — not to mention downright adorable — this work can be.

Sea otters are called "keystone" species, meaning that they are the linchpin that holds their ecosystem's food web together. A long-running line of ecological research has found that when sea otters are present in coastal ecosystems, populations of sea urchins (one of their favorite foods) are kept in check, allowing marine kelp forests to proliferate. This is a balanced, healthy coastal ecosystem. But when sea otters disappear, sea urchin numbers explode, they eat all the kelp, and the coast starts to look pretty bleak.   

Sea otter populations are still recovering from the effects of hunting for the fur trade in the 18th and 19th centuries, and their protection remains an important objective for California's Monterey Bay Aquarium. Between 2002 and 2015, a team of aquarium scientists, led by Karl Mayer, rescued 37 stranded and orphaned sea otter pups along the coast. They brought them back to the aquarium and gave them to captive female otters to raise as their own. After the pups were weaned, they were released into the Elkhorn Slough wetland, an estuary that is managed by state and federal natural resource agencies. This in itself was a great success, but Mayer and his team wondered about the fate of these released pups and how much they contributed to their newly adopted wild population — an important mark of how successful the aquarium's rehabilitation and reintroduction project truly is.

They found that released female otters reproduced at the same rate as fully wild otters, an encouraging sign that reintroduction can contribute to a healthy wild sea otter population. In fact, over the lifetime of their study, the reintroduced females and their own wild pups accounted for 55% of the growth of the Elkhorn Slough sea otter population! This is fantastic news for California's sea otters, and shows how captive animals can contribute to conservation of their wild counterparts. 

a sea otter with long whiskers looking at the camera

Photo from MaxPixel 

You probably didn't need another reason to love sea otters, with their hilarious old-man whiskers and their penchant for hand-holding, but let's add this conservation triumph to the list, anyway.

NIH seeks to enroll one million individuals in genetic counseling to improve health research diversity

Medical research has had a long history of disproportionately benefiting wealthier countries and white people, rather than ethnic minorities

Luyi Cheng

Molecular Biology and Structural Biology

Northwestern University

The National Institutes of Health’s ambitious All of Us Research Program aims to promote diverse and inclusive health research. In a milestone move, they recently awarded $4.6 million to Color, a health technology company, to establish a nationwide genetic counselling resource in the U.S.

Medical research has had a long history of disproportionately benefiting wealthier countries and white people, rather than ethnic minorities. We see this consequence resulting from clinical trials and massive databases that under-represent racial, ethnic, gender, sexual orientation, socioeconomical and geographical minority groups. Unsurprisingly, this effect is also related to how these underrepresented populations have poorer access to quality health care

To combat this, the NIH began its All of Us Research Program in 2018 with the goal of enrolling at least 1 million diverse participants in the United States to improve health programs and biomedical research. They planned to collect completed health questionnaires, medical records, physical measurements and more, which researchers could use to improve diagnosis, treatment, and prevention methods for all individuals.

The All of Us Research Program also collected another piece of data from their participants: their DNA. They wanted to sequence the genomes of their 1 million participants. A year later, they’ve reported that out of the more than 175,000 participants so far, 80% of them come from historically underrepresented groups. With this progress, a game-changing move followed.

People at a pharmacy counter getting medication

The company Color will be building a nationwide genetic counseling service to communicate the results back to participants transparently, responsibly and ethically.

Tbel Abuseridze on Unsplash

The program has given the $4.6 million to Color, a California-based health technology company, to sequence and analyze these genomes. Color will use the money to start building a nationwide genetic counseling service to communicate the results back to participants transparently, responsibly and ethically. They anticipate the service to be especially helpful for participants found to be at potential risk for genetic diseases or adverse side effects to clinical drugs.

While I feel elated with this encouraging progress, it’s also long overdue. We should expect healthcare and science to be diverse and inclusive, and we are each accountable for that responsibility as well. I hope this research program will achieve the beneficial impact every individual fully deserves, and that science will serve the communities that it should have been from the start.

Opioid use after surgery is higher in the U.S. & Canada compared to Sweden

A new study investigates whether the culture surrounding pain medication prescription habits in different countries could be contributing to opioid misuse

Juliann Tefft

Biomedical Engineering

Boston University

In 2017, more than 130 people died per day in the US from opioid related drug overdoses. This crisis has triggered a call to hold drug companies responsible for putting Americans at risk. In August 2019, a landmark ruling in Oklahoma fined Johnson & Johnson $572 million for their ‘public nuisance’ marketing strategies, and it remains to be seen whether this decision will set a precedent towards more drug companies being held accountable in the future. 

But even if we hold drug companies responsible for the opioid crisis, how will the country move forward from here towards recovery?

To help answer this question, a recent study investigated whether the culture surrounding pain medication prescription habits in different countries could be contributing to opioid misuse. 

People at a pharmacy counter getting medication

Researchers asked the question: after surgery, do the rates of opioid prescriptions dispensed vary between the United States, Canada and Sweden?

Tbel Abuseridze on Unsplash

The researchers compared patients undergoing low-risk surgeries in the US and Canada (the two countries with the highest per capita consumption of opioids) with patients in Sweden, and found that patients in the US (76.2%) and Canada (78.65) were seven times more likely to fill opioid prescriptions after surgery compared to Swedish patients (11.1%). And of these prescriptions, 45% of prescriptions in the US surpassed a threshold equivalent to 200 mg of morphine compared to just 5.4% in Sweden. 

The large dataset allowed researchers to compare demographically similar patients and conclude that systemic factors, such as prescribing habits, public attitudes towards pain medication, and the drug marketing and regulatory processes, were likely impacting US prescription numbers more than individual patient needs. 

These numbers highlight a stark difference in the drug culture of the US compared to Sweden. Although the data in this study cannot represent the number of pills that patients consumed, a 2018 study found that the US patients consume between 5-59% of their prescribed opioids, and an overwhelming 70 percent of people kept these unused pills. With 11.4 million Americans misusing prescription opioids per year, it stands to reason that America’s recovery from the opioid epidemic may require systemically altering how drugs are prescribed. 

Some changes have already begun: in 2016, Massachusetts was the first state to implement a seven-day limit on opioid prescriptions to reduce the amount of unused drugs available in homes, a practice that many US states have implemented since then. Additionally, studies investigating how to manage pain through short-term opioid prescriptions or non-opioid pain medications, like acetaminophen and ibuprofen, will be of great value moving forward. While solving the opioid crisis will take time, quantifying the pain management needs of patients and organizing the vast data sets of prescription information can help us formulate solutions.

The unique chemistry of cats' guts make them the perfect host for Toxoplasma gondii

This information might allow Toxoplasma researchers to switch from lab cats to lab rats

Alyssa Shepard

Cancer Biology

The Scripps Research Institute

Toxoplasma gondii is a common parasite that causes an infection called toxoplasmosis in approximately one-third of humans, so research in this area is important to human health. T. gondii's lifecycle is curiously complex, and it has gained infamy for it's tendency to reproduce in the intestines of cats. The reason for this exceptional specificity has previously been unknown. Now, a study published in PLOS Biology in August has identified the exact molecular components in the feline intestine that create the conditions necessary for the parasite to reproduce. 

The research found that a chemical called linoleic acid is necessary for the sexual lifecycle of T. gondii. An enzyme in the intestines of most mammals called delta-6-desaturase usually helps convert linoleic acid to arachidonic acid. But cats are the only mammal known to lack this enzyme in their guts –  therefore, their guts maintain high enough levels of linoleic acid to allow for the parasite to reach sexual maturation. After the researchers figured this out, they found a way to stop the activity of delta-6-desaturase in mice, which means that in the future they may be able to stop using cats – a point of contention with animal rights activitists – in the lab. Eventually they may even be able to grow T. gondii in cell culture to learn more about this common (and, some say, mind-controlling) parasite. 

How humans have shaped the brains of our furry friends

By breeding dogs for specific behaviors, humans have also altered the physical structure of their brains

Claudia Lopez-Lloreda

Neuroscience

University of Pennsylvania

Dog-watching at the park on a Sunday morning makes us appreciate the diversity across different breeds. From tiny Yorkshire Terriers to giant Great Danes, each breed has its own unique characteristics. Although dogs may be bred for specific physical traits like size or coat length, they can also be bred for specific behaviors like hunting or herding. Researchers wanted to know if these behavioral specializations were associated with differences in brain structure. 

Four dogs on a leash in a park. One of the dogs has its mouth open, either yawning or barking.

Photo by Matt Nelson on Unsplash 

A new study published in the Journal of Neuroscience and led by researchers at Harvard University looked at the brains of 62 purebred dogs from 33 different breeds to answer this question. Using magnetic resonance imaging (MRI), they found that there were significant differences in brain anatomy between different breeds. Furthermore, these differences could not be fully explained by variation in brain size or skull shape. 

Researchers looked at brain anatomy in six different networks, each associated with different potential functions like drive and reward or social action and interaction. Fascinatingly, these networks correlated with specialized behaviors seen in different breeds. For example, sight hunting, a behavior for which Greyhounds are bred, was associated with brain areas related to eye movement and spatial navigation. Moreover, they found that  brain variability between breeds had arisen fairly recently (in an evolutionary sense), indicating that selective breeding by humans is most likely responsible for molding the brains of different dog breeds. The authors state that dogs represent a great “natural experiment” that could become a good model to study brain variation and its relationship with function in light of evolutionary pressures. 

The rise of a mysterious lung illness begins to expose the dangers of vaping

The U.S. Centers for Disease Control have reported at least 450 cases in 33 U.S. states, as policy makers call for action

Marnie Willman

Virology

University of Manitoba Bannatyne and National Microbiology Laboratory

Walking through a park, across a street, or heading to work, all of us have suddenly caught the scent of fruit, chocolate, peppermint, or some other flavor coming from someone vaping nearby. As vaping has rapidly gained popularity since it’s invention in 2003, little has been said or written about its potentially dangerous health impacts. Many shops and restaurants in the U.S. and Canada have banned vaping on patios, near doors of establishments, and other public areas where smoking cigarettes is not permitted. Now, vapes have made the news in a negative light for the second time.

 As CBC reported on August 23, 2019, an Illinois resident passed away following severe respiratory illness likely brought on by vaping, according to the U.S. Centers for Disease Control. Currently, the CDC is investigating at least 450 cases of severe respiratory illness across 33 states, all thought to be related to chronic vape use. The cause is yet unknown, and Canada's chief public health officer, Dr. Theresa Tam, reported to the media that the mysterious illness has not yet reached Canada. Tam also cautioned that everyone should be aware that the long-term effects of vaping, given that the number of chemical ingredients in vape oils, are unknown. 


We may not know the exact link between vaping and this lung disease, but we do know some things about the dangers of vaping. Vaping entails inhaling steam and other chemicals, like formaldehyde, into the lungs. Human lungs are coated with mucus inside that protects lung cells by catching particulates before they infiltrate the rest of the body. Exposure to these particles thickens the mucus layer inside the lungs, decreasing the lungs' ability to fight off respiratory infections. Inhaling steam also prevents the lungs from absorbing as much oxygen as they should.  Lower oxygen levels in the body decreases the health and functioning of major organs and muscles. In addition to these, the negative effects of ingredients in vape oil remain unknown and/or unreported.

These health risks of inhaling a foreign substance of any kind into your lungs point to potential dangers of long-term vaping use. While the cause of death and illness in individuals who vape isn't exactly clear yet, one thing is certain: Health officials and policy makers — and even Donald Trump — are beginning to worry about the correlation between the illnesses and increased vape use. We are probably just seeing the beginning of vaping-related diseases and deaths.

Shapeshifting hydrogels with CRISPR inside rearrange on command and interface with our bodies

Programmable CRISPR-responsive smart materials, like DNA hydrogels, are much more likely to become game-changers in our lifetimes

Tara Fernandez

Cell Biology

All eyes are on CRISPR, the gene-editing sensation touted to solve a slew of long-standing medical challenges, such as engineering CRISPR nanoparticles as a potential therapeutic for Alzheimer’s disease or working towards an antidote to box jellyfish stings. Now, a new study explores new territory where CRISPR has the potential to make its mark: smart biomaterials. 

Smart biomaterials are biologically responsive materials engineered to respond to internal and external cues, such as changes in light, temperature, pH or enzyme activity. Now, bioengineers at the Massachusetts Institute of Technology have taken smart biomaterials one step further by harnessing CRISPR’s unique DNA modifying properties to create DNA-hydrogels that change shape on command. These hydrogel polymers have web-like structures that are held together by DNA strands. Together with the programmable enzyme Cas12a, CRISPR precisely targets DNA bridges and cleaves them, triggering a shift in the polymer’s shape or consistency. 

These programmable CRISPR-responsive smart materials can be used to interface with various biological signals or enhance current biomaterial approaches, such as in the fields of tissue engineering and molecular diagnostics. In this particular study, the researchers engineered different DNA-based materials to explore different applications, such as using CRISPR-based DNA hydrogels to release enzymes, nanoparticles and live cells, and even modulating the hydrogel's electrical properties for sensing and diagnostics.

white defibrillator with stand

 CRISPR-controlled hydrogel technology is poised to revolutionize bioelectronics.

 Photo by Allie Smith on Unsplash.

In fact, CRISPR-controlled hydrogel technology is poised to revolutionize bioelectronics — electric circuitry that interfaces with biological systems, which may see medical devices to sense and destroy dangerous pathogens become a reality. 

Transitioning any innovation to a clinical setting involves plenty of time, investment dollars and regulatory red tape. Compared to the safety risks involved in directly treating patients with CRISPR, CRISPR-based DNA hydrogels are much more likely to become game-changers in our lifetimes.

Meet the all-star cast of marine bacteria that can ruin your warm-weather activities

Each member of the Vibrio family is unique, but they're all likely getting more common as the oceans warm

Max Levy

Chemical Engineering

University of Colorado Boulder

It’s official. This summer was one of the hottest on record, and July was the warmest month ever recorded on the planet. The sweltering summer was a boon for bacteria from the Vibrio genus. Several reports of flesh-eating bacteria, Vibrio vulnificus, are dotting America’s coastline with casualties. Sea temperatures are high, rising, and stretching these bugs to new beaches — a new normal in this climate crisis. But if more abundant flesh-eating bacteria weren’t daunting enough, entirely different species of Vibrio infections are also predicted to rise.

So, meet the all-star cast of marine bacteria that can ruin your warm-weather activities and tropical vacations:

Vibrio vulnificus: This “flesh-eating” bad boy causes lethal infections in wounds, as well as shellfish poisoning. Does necrotizing fasciitis sound appetizing?

Vibrio anguillarum: Likely voted “Most Likely to Decimate Shellfish Supplies” in high school (if bacteria went to high school, that is), this bacterium threatens aquaculture of crustaceans and fish.

Vibrio cholerae: Cholera. Yes, that cholera. Millions of people infected annually, lethal in hours if untreated.

Vibrio alginolyticus: This angsty germ seems to thrive on being a nuisance. It produces the famous neurotoxin in pufferfish and also causes swimmer’s ear.

Because each of these Vibrio species (and others) thrive in warm waters, they are all expected to get a boost from climate change.  With all the bacterial diversity in the world, it’s hard to believe that  this little-discussed group could be such a problem. But warming ocean temperatures may well put Vibrio on course to being a household name. 

Happy swimming and seafood-eating! 

Unhatched turtle embryos can shape their own sexual destinies

By moving to cooler areas inside the egg, turtle embryos can influence their own sex, and maybe ward off climate change too

Brittney Borowiec

Comparative Physiology

McMaster University

A turtle develops into a male or female depending on temperature  – females hatch from warm eggs and males hatch out of cool eggs. Turtle nests naturally fluctuate in temperature, and this variation leads to clutches producing a mix of male and female hatchlings. 

But a new study in Current Biology suggests there’s more to it than that: instead, embryos can guide their own sex determination by moving between warmer and cooler parts of the egg.

One end of a turtle egg can be as much as 4.5 °C (40.1 °F) warmer than the other end, meaning that embryos experience very different temperatures depending on where they are in the egg. Intrigued, the researchers then tested whether embryos could sense and respond to these temperature differences. Could unhatched turtles perhaps influence their own development?

To do this, the team treated the eggs with capsazepine, a drug that shuts down key ion channels involved in temperature sensing, and recorded how embryos responded to a heat source on one end of the egg. Drugged embryos didn’t move towards the heat as much as control animals, and were far more likely to develop into males.

Turtle embryos have the raw tools – a big thermal gradient and the ability to sense and respond to warmth – to influence their own development.

Global climate change threatens turtles and other animals that rely on temperate-dependent sex determination by disrupting sex ratios. We’ve already seen examples of this in the wild – a few years ago, scientists were dismayed to find 99% of green sea turtles sampled at key breeding sites in Australia were female, crippling their ability to reproduce. 

Green sea turtle underwater

Global climate change threatens turtle survival by disrupting sex ratios.

Tim Briggs

The razor-thin margins between “all male” and “all female” nests combined with the frantic pace of global warming means that some populations are already on the precipice of ecological disaster. While being able to shimmy a couple of inches in an embryo isn’t going to stop catastrophic changes in sex ratios, it may allow turtles to buffer the short term effects of climate change. 

Ant activity has outsize impacts on soil moisture and plant growth

Consortium member Madison Sankovitz explains her newly published research study

Madison Sankovitz

Entomology

University of California Riverside

Although ants are well-known as being household pests, most of our terrestrial landscapes would likely be drastically different without them. Ants provide an essential ecosystem service by maintaining soil. They aerate soil by digging tunnels for their nests (which also allows water to reach plant roots), and they mix nutrients through soil. 

Ants’ nest-building and foraging behaviors help soil remain fertile for plants and microorganisms to thrive. In fact, many plants would not even be able to grow where they do if ant nests didn’t exist. In a newly published study, I and two of my colleagues at the University of Boulder - Colorado have shown that factors like proximity to an ant nest and whether the nest is on a slope substantially influence the soil moisture and plants that live in the area. 

We investigated patterns in the soil properties and plant communities surrounding 24 nests of the montane ant, Formica podzolica. After counting plant specimens and studying plants and soil in the lab, we found that soil moisture increases with distance from nests and that plant abundance decreases with distance from nests. We also found that the soil downhill from nests harbors more plants than soil uphill from nests, which we conclude means that nutrients and water from nests flow downhill to fertilize soil. This ant species occupies a huge geographic range from Alaska down to New Mexico, so we think they play a key role in shaping plant communities throughout much of the western U.S. and Canada.

Our study adds to a body of literature about ants as "soil ecosystem engineers." Without ants, subalpine habitats like the one in this study could be extremely different. We and other scientists continue to study how ant activity affects the soil, including the possibility of harnessing their services in both ecosystem restoration and agricultural crop production. 

Scientists tried to make knives out of frozen human poop

They wondered: is it possible to cut animal hides with a human feces blade?

Farah Qaiser

Molecular Genetics

University of Toronto

Have you ever wondered if knives manufactured from frozen human feces could function as well as regular knives? While the thought has never crossed my mind, researchers at Kent State University and the Cleveland Museum of Natural History wondered about this very question, and sought to find the answer.

And yes, there's a good reason why.

In Shadows in the Sun: Travels to Landscapes of Spirit and Desire, Colombian-Canadian anthropologist Wade Davis recounted an ethnographic account (below) of an Inuit man who manufactured a knife, using his own frozen feces, to butcher a dog: 

“There is a well known account of an old Inuit man who refused to move into a settlement. Over the objections of his family, he made plans to stay on the ice. To stop him, they took away all of his tools. So in the midst of a winter gale, he stepped out of their igloo, defecated, and honed the feces into a frozen blade, which he sharpened with a spray of saliva. With the knife he killed a dog. Using its rib cage as a sled and its hide to harness another dog, he disappeared into the darkness.” - Wade Davis

Despite this story being shared across multiple documentaries, books, and academic literature, the credibility of this story remains uncertain. Can such a knife actually cut through hide, muscle and tendons? 

To test this claim, the researchers collected human feces to make such a knife. First, researcher Metin I. Eren went on a diet high in protein and fatty acids — consistent with an Arctic diet — for eight days. This diet included chicken thighs, beef fillets, turkey sausages, and salmon. From day four onward, Eren's fecal material was collected and frozen at -20°C. Frozen fecal samples were then either molded by hand or through ceramic molds to create knives. After burying each knife in -50°C dry ice for a few minutes, researchers attempted to slice through pig hide, muscle and tendons to test knife functionality.

Hand shaped poop knife

An example of a “hand-shaped” knife blade.

Michelle R. Bebber & Metin I. Eren. 

Unsurprisingly, the knives manufactured from frozen human feces could not cut through the pig hide — let alone tendons or muscle. Instead, the edge of the knife would melt upon contact with the hide, and leave behind fecal streaks. Even knives shaped from feces from a typical Western diet failed to cut through pig hide.

A knife made from frozen human feces fails to cut through a pig hide, melting and leaving streaks instead.

A knife made from frozen human feces fails to cut through a pig hide, melting and leaving streaks instead.

Michelle R. Bebber & Metin I. Eren. 

To be clear, tools manufactured from human feces do exist. For example, you can be innovative when it comes to waste management in space missions, and use solid human waste to produce polyhydroxybutyrate and then 3D print items for astronauts

While there are countless tales reporting the innovative and resourceful nature of Indigenous and prehistoric people, this particular claim is unlikely to be true. The researchers do suggest exploring the role of different diets or even licking the frozen fecal knife (as reported in the original tale) to further test this claim, but regardless, they remain confident that they gave their knives the best possible chance to succeed and the knives still couldn’t function. 

So no, knives manufactured from frozen human feces do not work.

Just in case you were planning to try that out one day. 

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