How do you tell apart seemingly identical fanged frogs from Thailand?

Distinguished frogs

It turns out, say Chatmongkon Suwannapoom and Maslin Osathanunkul, that a good way to distinguish one kind of fanged frog from another is to do melting analysis.

Their report, “Distinguishing fanged frogs (Limnonectes) species (Amphibia: Anura: Dicroglossidae), from Thailand using high resolution melting analysis“, explains how they achieved the “rapid and accurate identification of six species of Limnonectes of the L. kuhlii complex”.

The thing they melted was a specific region of RNA from the ribosomes of each frog. Plotting the temperatures at which the frogs’ ribosomes’ RNA does or does not melt creates a separate, easily distinguishable curve for each kind of frog.

Eyeballing, the technologically simpler technique used by frog scientists back when frog scientists were called “naturalists”, has its limits. Melting exceeds some of those limits.

Cats on cannabis

The full effects of cannabis – like, come to think of it, the full effects of anything – on humans still hold some mysteries.

So it is with cannabis and cats. Chloe Lyons and her colleagues at the University of Saskatchewan, Canada, have made some progress about the cats.

Writing in Frontiers in Veterinary Science, they describe what happened when they gave 12 cats two oral doses of a cannabis herbal extract (the acronym for which is CHE). Some cats received a dosage more than double what the others got.

Reader Stefan Lalonde points out a study highlight: a photo of a lavishly drooling cat. A second cat also drooled. The report states: “these two cats clearly hypersalivated”.

The scientists express surprise about the cats: “Salivation shortly after dosing was observed in two cats in the high dose group; these animals had substantially lower cannabinoid concentrations than other cats in this group.”

The team speculates about the mechanism that caused the drooling. “Cats are notorious for ‘spitting up’ oral medications which they conceal in their oral cavity, and it could not be confirmed that all cats swallowed the entire CHE dose,” the researchers write. “Any oil-based CHE retained in the oral cavity may have prompted the cat to salivate, and subsequently been expelled from the mouth.”

This unexpected twist in the who-drools data hints that the relationship between hunger and cannabis consumption in cats may be complex.

Or that these two particular cats were eccentric, one way or another.

A sticky issue

At sea, there is spice. Feedback still delights in how oceanographers decided that some ocean water can be called “spicy” and other ocean water “minty” (8 October 2022). Here’s further delight: in the air, there is “stickiness”.

Reader Earle Spamer brings news of the latter. “Here’s a paper that brandishes a ‘new’ variable in climate studies: stickiness,” he writes. “An awful lot of mathematics to explain what my grandmother knew just by sitting on the front porch.”

The paper is “Stickiness: A new variable to characterize the temperature and humidity contributions toward humid heat” by Catherine Ivanovich at Columbia University and her colleagues, published in the Journal of the Atmospheric Sciences.

“We derive a novel thermodynamic state variable named ‘stickiness’,” they write. This is “analogous to the oceanographic variable ‘spice’ (which quantifies the relative contributions of temperature and salinity to a given water density)”. Stickiness “quantifies the relative contributions of temperature and specific humidity” to the more traditional way of measuring temperature.

Word by common word, scientific specialties adapt familiar, sticky old ideas and names to help expose and explore the easy-to-overlook complexities of the universe.

Ketchup cardio claim

Feedback’s recent insights on ketchup (16 March) set at least one reader’s heart racing.

David Watson writes: “Years ago, before the advent of disposable adhesive electrodes, I was having an electrocardiogram [ECG]. The electrodes then were little rubber cups suckered onto your skin using a conductive gel. I remarked to the cardiologist that the gel was probably ridiculously expensive. He said it was, and a group had researched cheaper alternatives. They found one with the right combination of surface tension, viscosity and conductivity. Unfortunately, it was low on patient acceptability – ketchup, of course.”

Documentation of that doctor’s claim (which may have been just a jest) seems scarce. Feedback has so far found only a pooh-poohing, in a 1981 study by Andrew P. B. Lee, “Biotechnological principles of monitoring“, published in International Anesthesiology Clinics.

Lee wrote: “Most electrode jellies sold are no more effective than K-Y jelly or tomato ketchup at lowering the skin-electrode impedance.”

If you find convincing evidence in favour of ketchup’s use as a conductive gel for electrocardiograms, please send it over.

Marc Abrahams created the Ig Nobel Prize ceremony and co-founded the magazine Annals of Improbable Research. Earlier, he worked on unusual ways to use computers. His website is improbable.com

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