Scientists find that parasites dramatically alter how much methane a sheep emits.
It’s estimated that 40% of greenhouse gas emissions come from agriculture, and a substantial portion of that is directly ’emitted’ by livestock. And just last year, climate scientists reported that we’ve actually been underestimating the extent to which the combined belches and flatulence of farmed animals contributes to climate change by 11%. Unsurprisingly, there’s been renewed interest in reducing those emissions, especially considering the demand for livestock is only growing. Now, scientist from the UK report one thing that will help: keep the animals parasite-free.
Doctors recently discovered rat lungworm in Chinese red-headed centipedes after two people became ill from eating them raw. Centipede Photo: Yasunori Koide
When the 78 year old woman arrived at the hospital, it was clear something was wrong. She’d been suffering from headaches and been in a drowsy fog for weeks. So doctors checked her cerebral spinal fluid, and found it was cloudy and yellow instead of clear. It was brimming with white blood cells, indicating an infection. This, alongside a positive antibody test, led to a diagnosis of angiostrongyliasis—an infestation of the parasite rat lungworm (Angiostrongylus cantonensis).
As the name implies, rat lungworms usually set up shop in rat pulmonary arteries. But their complex lifecycle involves spending time in an intermediate host like a snail before making a home inside a rodent. If we happen to eat that infected host before a rat does, they can end up inside us instead, where they can get lost and cause serious infections in other places. The parasites are most dangerous when they make their way into the brain, causing swelling and inflammation—like the woman was experiencing. But the woman hadn’t been eating snails.
A few weeks later, her 46 year old son was also admitted, and he, too, was diagnosed with angiostrongyliasis. Both were cured after a few weeks on an antiparasitic and steroid. But the question remained as to how they became infected—he wasn’t eating snails, either. But, it turned out, both he and his mother had been consuming raw centipedes from a local market. And that led the doctors to question: could centipedes also carry rat lungworm? Continue reading “Centipedes Can Carry Rat Lungworm—Just In Case You Needed A Reason Not To Eat Them Raw”
The risk might be low, but the alternative is maybe months of debilitating diarrhea. It’s your choice. Photo Credit: Timothy Epp/Shutterstock
While we like to think of ourselves as rational creatures, there’s no doubt that human beings are actually quite awful at assessing risk. So I can understand why Ethan Linck thought to contextualize the risk of drinking from backcountry streams with data. “Life is triage, a constant series of negotiations between risks of varying severity,” he wrote. “And how we talk about those risks matters.”
Yes, it does—which is exactly why his piece in Slate last week was so damaging. It was anything but a careful, scientific evaluation of the risks. Wes Siler over at Outside Magazine already pointed out a myriad of issues with the article, but I want to zero in on the actual data, because Linck claimed to be looking at the matter scientifically. Instead, he cherry-picked sources to argue against doing one of the simplest things you can do to protect yourself from some truly awful diseases when you’re backpacking: treating your water. Continue reading “Backpackers, Don’t Listen To Slate: Science Does Support Stream Water Treatment”
These tough bats can tussle with the deadliest scorpions in North America and win. Photo by Connor Long
Pallid bats (Antrozous pallidus) are quirky little creatures, the sole species in their genus. Their long ears, which can equal half their body length, make them look quintessentially batty, but unlike most of their night hunting relatives, they prefer to tackle ground-dwelling dinners—a strategy called “gleaning.” Pallid bats glean as much as half their body weight in prey every night, and their diet includes a wide range of crunchy little critters, including crickets, praying mantis, and beetles.
It is their taste for scorpions, though, that is particularly intriguing, and piqued the curiosity of scientists. It was unknown whether the bats have a trick for catching scorpions that keeps them from being stung, or whether they are resistant to the animals’ agonizing toxins. In a new PlosONE paper, researchers show it’s the latter: the bats’ laissez-faire attitude towards venom stems from an invulnerability to scorpion neurotoxins due to alterations in the voltage-gated sodium channels that the toxins target. Continue reading “Tiny Bat Shrugs Off Stings From Deadly Scorpion”
One of the world’s deadliest venomous animals—a female Anopheles gambiae—demonstrating the behavior that makes her so lethal. Photo Credit: CDC/ James Gathany
People are often surprised when I say that mosquitoes are the deadliest venomous animal in the world (the deadliest animal period, really, if we don’t count ourselves). Mosquito bites—and the venoms delivered by them—kill upwards of 750,000 people worldwide every year thanks to the lethal beasties harbored within them. Most of those are due to microscopic parasites in the genus Plasmodium, which are responsible for the diseases collectively called malaria. Malaria accounts for around 500,000 of those mosquito-caused deaths, according to the World Health Organization—only a fraction of the over 210 million cases of malaria reported every year. Not surprisingly, there is a lot of time, money, and intellectual capital being invested into finding ways to reduce those numbers. And as the vectors, mosquitoes—especially the few species that carry the most devastating diseases—are a key target.
While killing mosquitoes seems like a simple objective, it can be quite complicated in practice. Mosquitoes are hardy little buggers, and rapidly evolve resistance to pesticides. And when effective pesticides can be found, such as DDT, they tend to be a little too effective, killing a wide diversity of insects and causing ecological harm to local biodiversity. In the hope of wiping out disease-carrying mosquito populations, scientists have tried all sorts of methods, from increasing natural predators to releasing sterile male mosquitoes in swarms. But the most recent approach sounds like it’s straight out of a science fiction thriller: an international team of scientists has genetically engineered a fluorescent fungus that wipes out mosquitoes using venom toxins from spiders and scorpions. Continue reading “FrankenFungus Armed With Venom Toxins Could Join The War Against Malaria”
Scientists refer to the study of biological toxins as toxinology. From bacterial toxins like anthrax to the deadliest snake venoms, toxinology examines the chemical warfare between animals, plants, fungi and bacteria. In my Toxinology 101 series, I explain and explore the fundamentals of toxin science to reveal the unusual, often unfamiliar, and unnerving world created by our planet’s most notorious biochemists.
One of the most frequent questions I receive as a venom scientist (so much so I dedicated an entire chapter of my book, Venomous, to it) is some variant of What is the deadliest toxic animal? While that seems like there should be an easy answer, as with anything in the natural world, defining deadliness is messy. To answer that question, you have to be clear about what you’re reallyasking. Is the subtext of the question What animal is most likely to kill me? Or What animal should I be most afraid of running into? Or more simply, What animal produces the most potent toxin, because I’m a biochemistry nerd and I’m just curious? Each of those questions is answered a bit differently, and even still, it’s complicated. Continue reading “Measuring Deadliness | Toxinology 101”
By tweaking a compound from bee venom, scientists may have created a molecular Trojan horse to deliver drugs to our brains. Photo by Flickr user joeyz51
We human beings are quite fond of our brains. They are one of our largest and most complex organs, weighing in at nearly three pounds (2% of our bodies!). Each contains upwards of 90 billion neurons responsible for controlling our gangly, almost hairless primate bodies as well as processing and storing a lifetime’s worth of events, facts and figures. So we protect our brains as best we can, from hats that battle temperature extremes to helmets that buffer even the most brutish blows.
Our bodies, too, protect our brains vigilantly. Select few compounds are able to cross the blood-brain barrier, a membrane which shields our most essential organ from the hodgepodge of potentially-damaging compounds that might be circulating in our blood. The staunchness with which our brains are guarded internally is usually great—except, of course, when doctors need to deliver drugs to brain tissues.
It’s not too hard to get some molecules across, assuming they are small and/or fat-soluble, like many anti-depressants, anti-anxiety meds, or notorious mind-altering substances like alcohol and cocaine. But larger molecules, even important ones like glucose, have to be specifically pulled across this divide between our blood and our brains. That means that some life-saving drugs, such as chemotherapy agents targeting brain tumors, need help getting into our heads. And that is where the newest venom-derived product—MiniAp-4—comes in. Continue reading “Bee derived molecular shuttle is the newest buzz-worthy venom product”
Meiacanthus atrodorsalis—a pretty little fish with a venomous bite. Photo by Klaus Stiefel via Flickr
“Did you tell her the one about George Losey and the blenny?” Rich Pyle asked with a knowing smirk. Pyle and I were sitting in the living room of legendary ichthyologist Jack Randall for a piece I was writing about him for Hakai Magazine. “It’s a good venom story,” Pyle continued, grinning.
Randall’s eyes lit up with mischievious joy as he launched into the tale. He and George Losey were invited to Guam to bear witness to a massive crown of thorns sea star invasion, he explained (“It was one overlapping another as far as you could see,” he recalled; “They decimated the corals of the whole northern coast”). While he and Losey were diving, Randall saw a small blenny—one of a group of blennies that he knew Losey had taken an interest in. Since he had a three-pronged sling-style spear on him, Randall caught the fish, which remained wriggling on the end of his spear tip. He asked Losey if he wanted it to examine later, and Losey did, but he didn’t have any containers to put it in. So, Losey did what seemed like the obvious thing: he tucked the creature into his swim trunks. “Well, it has a venomous bite…” Randall said laughing—a fact which was unknown at the time. “It bit him right here, on the belly,” Randall gestured, “and he let out a yelp!” That was how George Losey first discovered the venomous nature of fang blennies in the genus Meiacanthus, Randall explained—by making the mistake of putting one in his shorts. Continue reading “Beware the blenny’s bite: scientists uncover the toxins in fang blenny venom”
UCI chemistry professor Ken Shea (right) and doctoral student Jeffrey O’Brien (left) have developed a potential new broad-spectrum snake venom antidote. Photo credit: Steve Zylius / UCI
Living in countries like the U.S., Australia, and the U.K., it can be all too easy to forget that snakebites are a serious and neglected global medical problem. It’s estimated that upwards of 4.5 million people are envenomated by snakes every year; about half of them suffer serious injuries including loss of limbs, and more than 100,000 die from such bites.
Much of this morbidity and mortality could be prevented if faster, easier access to the therapeutics that target and inactivate snake venom toxins could be established. But effective antivenoms are difficult to produce, expensive, and usually require storage and handling measures such as refrigeration that simply aren’t possible in the rural, remote areas where venomous snakes take their toll. Seeking to solve many of the issues, a new wave of researchers have begun the search for alternatives, hoping to find stable, cheap, and effective broad-spectrum antidotes to snake venom toxins. One such group at the University of California Irvine recently announced a promising new candidate: a nanogel that can neutralize one of the most dangerous families of protein toxins found in snake venoms.
Scientists refer to the study of biological toxins as toxinology (not to be confused with toxicology, with a C—as I explain below). From bacterial toxins like anthrax to the deadliest snake venoms, toxinology examines the chemical warfare between animals, plants, fungi and bacteria. This is the first in a new series I call Toxinology 101, where I explain and explore the fundamentals of toxin science to reveal the unusual, often unfamiliar, and unnerving world created by our planet’s most notorious biochemists.
“Point blank,” my friend, a commander in the US Navy, said firmly, when I asked what misused word or phrase really gets under his skin. “Definitely point blank.”
I asked why, and as he explained, I realized I’d been using the phrase wrong, too. To people familiar with firearms, hearing someone call an up-close gun shot “point blank” is like dragging nails on a chalkboard because that’s not what it means at all. Point blank (which may come from the French phrase pointé à blanc, referring to an arrow being aimed at a white spot at the center of a target) has nothing to do with close proximity to the shooter. Rather, point blank range is the distance at which a weapon aimed at a target succeeds in hitting it—where point of aim (e.g. the middle of the crosshairs) is the same as point of impact.
Bullets don’t travel in a straight line; from the moment they leave the gun, they are pulled by gravity. The further away your target is, the more you have to adjust for the arc of the bullet with the angle of the barrel of the gun. But the aiming line of sight is a straight line; point blank is where the bullet’s path and the line of sight cross. Adjustable sights allow you to aim your shot for a desired distance; thus, for long-range rifles, “point blank” could be set to 100, 200, or even 300+ yards away. Meanwhile, many handguns have fixed sights, so their point blank range is limited to whatever distance the gun is is zeroed to. Point blank range for such guns can be somewhat close—within fifty feet—but even that is much further than what most people think of as “point blank.” In fact, if a gun is literally pressed against the victim, then the point in the middle of the sights (which are usually on top of the barrel) isn’t where the bullet ends up—it’s off by the width of the barrel at least—so that isn’t point blank range. Different munitions have different maximum point blank ranges, depending on the weapon’s inherent ballistic properties, the aiming device used, and the type of bullet used.
A quick diagram showing how “point blank” can be somewhat close or hundreds of yards away.
It’s no wonder, then, that every time my friend hears someone was shot “point blank” (meaning gun to the head, or within a few feet), he gets a little prickly. Of course, there are words and phrases like “point blank” for every profession. Doesn’t matter if you’re an accountant, mechanic, or CEO, your job requires an understanding of the lingo of your field, and it can be frustrating when words with specific, important meanings are flung about incorrectly by everyone else.
For me, the ‘nails on chalkboard’ feeling comes whenever I hear people talk about their everday exposure to “toxins” or “poisonous” snakes. Though they’re often used interchangeably, the words toxin, venom, and poison (and their corresponding adjectives toxic, venomous, and poisonous) have very distinct meanings to toxinologists. So, it’s only fitting to kick off my Toxinology 101 series by explaining the differences between them and when it’s appropriate to use each of these terms. Continue reading “What’s in a name? Venoms vs. Poisons | Toxinology 101”
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