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Archive for 'Research News'

Mentos + Cola at Various Altitudes

Tuesday, March 31st, 2020

The mentos/cola experiment has reached new heights. Details are in the study:

Probing the Mechanism of Bubble Nucleation in and the Effect of Atmospheric Pressure on the Candy–Cola Soda Geyser,” Thomas S. Kuntzleman and Ryan Johnson, Journal of Chemical Education, epub 2020. The authors, at Spring Arbor University and at Doherty High School, Colorado Springs, Colorado, report:

The so-called Diet Coke and Mentos experiment is initiated by dropping Mentos candies into a bottle of Diet Coke or other carbonated beverage. This causes the beverage to rapidly degas, causing foam to stream out of the bottle. Simple application of the gas laws leads to the straightforward prediction that ejection of greater foam volume is expected at lower atmospheric pressure. This hypothesis is bolstered when principles of bubble physics are taken into account. This hypothesis was tested and confirmed by monitoring the foam produced during the Diet Coke and Mentos experiment at various altitudes above sea level.

Author Tom Kuntzleman sent us this lovely note:

Ryan Johnson and I recently examined the effect of altitude (and therefore atmospheric pressure) on the Diet Coke and Mentos experiment. To do so, we carried out the experiment in many places around the US at altitudes that ranged from below sea level in Death Valley to over 14,000 feet at the top of Pikes Peak. We had an absolute blast.

For my father’s day present in 2019, my family gave me permission to carry out Coke and Mentos experiments at various locations (elevations) as we traveled through Arizona, California, Nevada, and Utah for summer vacation.

What Chewed on That?

Wednesday, March 25th, 2020

Taphonomic detectives can easily get caught up in wondering what kind of animal chewed on things that deteriorated and decayed to the point where, when those things were found, the remains of those things deserved to be called “the remains.”

A chapter of the book Forensic Taphonomy and Ecology of North American Scavengers, by Susan N. Sincerbox and Elizabeth A. DiGangi, explores many of the many varieties of the who-chewed-that question.

The chapter has this abstract:

Chapter 5 – What Big Teeth You Have: Taphonomic Signatures of North American Scavengers

There are several taxa from vertebrate species of the North American scavenger guild that are important from a forensic standpoint. This chapter presents a summarized account of their habitats, distribution, behavior, morphology, and taphonomic signatures on bone and soft tissue. Case studies from the literature are used to illustrate or highlight particular behaviors or signatures. Distribution maps and photographs of several taxa are included, as are tables that summarize ecological and morphological characteristics of each species such as habitat, dental formula, animal size, conservation status, and typical taphonomic signatures. The taxa and species discussed include canids (i.e., the family that includes dogs), vultures, deer, corvids (i.e., the family that includes crows), crocodilians, opossums, felids (i.e., the family that includes cats), raccoons, rodents, sharks, pigs, and bears.

Is This True? “The Liar’s Walk—Detecting Deception with Gait and Gesture”

Friday, March 20th, 2020

A new study about walking and liars and computers is bountiful for teachers who want their students to decide whether to believe bold claims. See if you can count the bold claims made in the study.

The Liar’s Walk—Detecting Deception with Gait and Gesture,” Tanmay Randhavane, Uttaran Bhattacharya, Kyra Kapsaskis, Kurt Gray, Aniket Bera, Dinesh Manocha, arXiv:1912.06874v1, December 14, 2019.

The authors, at the University of Maryland and the University of North Carolina, explain:

We present a data-driven deep neural algorithm for detecting deceptive walking behavior using nonverbal cues like gaits and gestures. We conducted an elaborate user study, where we recorded many participants performing tasks involving deceptive walking. We extract the participants’ walking gaits as series of 3D poses. We annotate various gestures performed by participants during their tasks. Based on the gait and gesture data, we train an LSTM-based [Long short-term memory] deep neural network to obtain deep features. Finally, we use a combination of psychology-based gait, gesture, and deep features to detect deceptive walking with an accuracy of 93.4%…. To the best of our knowledge, ours is the first algorithm to detect deceptive behavior using non-verbal cues of gait and gesture.

The researchers made use of bits of knowledge and belief they found in many places:

In addition to extracting gaits, we also annotate the gestures performed by the participants during the four walks. Prior literature on deception suggests that people showing deceptive behavior often feel distressed, and levels of discomfort can be used to detect a person’s truthfulness. These levels of discomfort may appear in fidgeting (adjusting their shirt/moving their hands) or while glancing at objects such as a clock or a watch. Touching the face around the forehead, neck, or back of the head is also an indicator of discomfort related to deception. We use these findings and consider the following set of gestures:{Hands In Pockets, Looking Around, Touching Face, Touching Shirt/Jackets, Touching Hair, Hands Folded, Looking at Phone}.

Eating gold: ok or not ok? [study]

Monday, March 16th, 2020

Is it a good idea to eat gold (in the form of gold leaf)? Prof. Koichi Imai, D.D.S., Ph.D of the Dept. of Biomaterials, Osaka Dental University, Japan (and other places), is of the opinion that the answer might well be ‘no’. Pointing out that although :

“Gold leaf flakes are considered to pass through the body and excreted without reaction with digestive juices.”

– there is a possible, and previously underplayed, potential problem :

“ [..] small gold leaf particles are likely to stay in the human digestive tract for a long time.”

Therefore :

“Ingestion of pure gold as food is not useful for humans, and the risk of carcinogenesis is considered. It is necessary to develop a safe edible gold leaf alloy which is completely dissolved in the digestive tract.”

See: Concern of carcinogenic risk of eating gold leaf (gold foil)-in relation to asbestos carcinogenesis mechanism  in Nano Biomedicine, 2018 Volume 10 Issue 1 26-30.

Photo Credit : “Hamachi” by Wojohowitz is licensed under CC BY-NC 2.0

Research research by Martin Gardiner

Saying “FACE”, in gatherings in pandemic times

Sunday, March 15th, 2020

How to get people to pay more attention to NOT touching their eyes, nostrils, or mouth?

We invited people, in a gathering, to say “FACE” whenever they saw a speaker touching a hand to their face. And most of those people said “FACE”, cheerily—appreciating that they were talking to themselves as much as to the person who was at that moment doing the face-touching.

You can experiment with this tiny technique, if you have to be in meetings of any kind during this time of pandemic. (If you work in a hospital or other healthcare setting, the technique might be a gentle, smiley-face inducing way to get patients and their families to alter their eyes/nostrils/mouth touching habits.)

Here’s how to do it:

  1. Invite the group to do it. (Please don’t order. Invite, invitingly.)
  2. Immediately ask the group to say “FACE” together, once or twice, so they will experience how it works.
  3. Consciously touch your hand to your face every few minutes during your talk, to give the group experience in saying “FACE”.

The technique—inviting people in a group to say “FACE”—is gentle, yet firm. Please feel free to try it.

The Manchester Experiment

We first tried this in a show at the University of Manchester, UK, on Wednesday evening, March 11, 2020. It worked. People paid more attention to NOT touching their eyes, nostrils, or mouth

This photo was taken by Herbert Crepaz, the final speaker in the show, as he was watching the first speaker speak.

That show, with an audience of 500 or so people, may have been the last public gathering to happen at the university until the corona-virus pandemic has burned itself out.

That show also was the first, and as it turned out, the only show on this year’s Ig Nobel Euro (and Brextannia) tour.

Clarifying the Advice

As mentioned above, “face touching” advice is mostly about touching eyes, nostrils, and mouth.

Forehead, cheeks, and chin are located, metaphorically and perhaps also physically, on a slippery slope to those eyes, nostrils, and mouth.

Here’s an illustration from “Face touching: A frequent habit that has implications for hand hygiene,” one of the few biomedical papers specifically about face touching:

A Science Question: How Medically Effective Is the Advice?

How good—good at preventing the spread of disease—is the advice to not touch hand to eyes, nostrils, or mouth?

We asked several biomedical researchers in three “the” countries (the USA, the UK, and The Netherlands). Each of them is a renowned physician who both treats patients AND does research. Each is based at a medical institution widely recognized as being among the world’s very best.

Here are representative opinions from two of those physician/researchers:

OPINION: “It is critical. Face touching—at all orifices and the eyes—needs emphasis as a medium for transmission of infectious diseases. Viruses are in or near facial orifices normally along with various bacteria and fungi. Transmission of virus from hand to facial orifice is a major route of infection. CDC is not just giving people something to do…. like witchcraft. Washing hands and not touching face will not end the pandemic, but the experts inform us the the disease may be slowed considerably.”

OPINION: “The Infectious Disease people I work with do seem to believe that this is correct advice, although I don’t know the evidence base. Nearly everyone I have discussed this with says, not that it isn’t effective—just that it is impossible. You have probably seen this compilation of news video of officials touching their faces.”

The entire above discussion is about the question: How medically effective (a lot? a little? hard to quantify?) is one very specific piece of medical advice.

Some things, many things, in fact, are difficult to measure.

And now for something completely different: Other, Aggressively Bad, Dangerous Advice

Let’s now look at some OTHER advice, that comes from far less reliable, but very loud and visible, sources.

Some of the OTHER medical advice raises—or should raise—a very different question.

That OTHER advice begs this question: How can you recognize advice that is aggressively bad, and dangerous?

There is plenty of aggressively bad, and dangerous advice being spewed by particular public officials.

And there is plenty of aggressively bad, and dangerous advice being spewed by particular propaganda organizations that disguise their propaganda, calling it “news.”

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