Archive for 'Research News'

Head-Shaking Research — Ejecting Water From the Ear Canals

Tuesday, September 19th, 2017

Ejecting water from a person’s ear canals is potentially thrilling, for fluid dynamicists and perhaps for the person. New research on the how and why will be presented at a meeting in November:

Acceleration induced water removal from ear canals,” Hosung Kang, Katelee Averett, and Sunghwan Jung, paper (Abstract D5.00007) to be presented at the 70th Annual Meeting of the APS Division of Fluid Dynamics, November 19–21, 2017; Denver, Colorado. The researchers, at Virginia Tech, report:

“Children and adults commonly experience having water trapped in the ear canals after swimming. To remove the water, individuals will shake their head sideways. Since a child’s ear canal has a smaller diameter, it requires more acceleration of the head to remove the trapped water.

In this study, we theoretically and experimentally investigated the acceleration required to break the surface meniscus of the water in artificial ear canals and hydrophobic-coated glass tubes. In experiments, ear canal models were 3D-printed from a CT-scanned human head. Also, glass tubes were coated with silane to match the hydrophobicity in ear canals. Then, using a linear stage, we measured the acceleration values required to forcefully eject the water from the artificial ear canals and glass tubes.”

The lab has also done research on how dogs drink, how cats drink, how diving birds enter the water, how raindrops hit tree leaves, what happens when wet hands clap, and other not-at-all-simple simple-seeming questions.

(Thanks to Nicole Sharp for bringing this to our attention.)

The aerodynamics of cheetahs’ tails (recent study)

Monday, September 18th, 2017

“During high-speed pursuit of prey, the cheetah (Acinonyx jubatus) has been observed to swing its tail while manoeuvring (e.g. turning or braking) but the effect of these complex motions is not well understood.”

Prompting, perhaps, the question ‘what is a cheetah’s tail actually for?’

A joint US / South African study (2016) has made made steps towards answers. A set of experiments, in which tails were aerodynamically tested at various airspeeds and inclinations, in a wind tunnel, yielded results :

“[…] our first order, quasi-steady state results clearly support the hypothesis that aerodynamic effects of the cheetah’s long, furry tail contribute to the angular impulse that can be applied to the body, especially at higher speeds. Both inertial and aerodynamic effects must therefore be considered in modelling the use of the cheetah tail for manoeuvring tasks. Our results further support the observations that the cheetah tail can be used as a ‘rudder’ to contribute to fast change of heading, and as a ‘stabiliser’ during rapid acceleration and turning.”

See: Quasi-steady state aerodynamics of the cheetah tail in Biology Open (2016) 5, 1072-1076


● The image shows the morphometric tail rig used to measure aerodynamic coefficient at varying angles of inclination and airspeed.

● The authors thank the Ann van Dyk Cheetah Centre for providing the tails.

● The authors inform that the use of the cheetah tails complied with the University of Cape Town Science Faculty Ethics policy.

Vegemite and Marmite (and cigarette butts): research studies

Monday, September 11th, 2017

A collection of research studies about Marmite and Vegemite enlivens and en-goos the (digital) pages of the special Cigarette Butts, Vegemite, and Marmite issue (vol. 23, no. 4) of the Annals of Improbable Research.

The issue’s table of contents is online. And you can obtain, for a pittance, the full issue, in PDF form.

Effect of Explosion-Puffed Coffee on Fruit Flies [research study]

Monday, September 11th, 2017

Fruit flies can be measurably affected by explosion-puffed coffee, suggests this new study:

Effect of Explosion-Puffed Coffee on Locomotor Activity and Behavioral Patterns in Drosophila melanogaster,” Bong Soo Ko, So Hyun Ahn, Dong Ouk Noh, Ki-Bae Hong, Sung Hee Han, and Hyung Joo Suh, Food Research International, epub 2017.

The authors, at several institutions in South Korea and the USA, report:

“Results of the underlying mechanism of the behavioral change patterns of explosive puffed [coffee]  with or without caffeine in Drosophila models, transcript level for the Dop1-R1 receptor in caffeine group was significantly higher than normal, PB, and DePB groups. Flies exposed to the caffeine had significantly decreased transcript levels for the GABA receptors. PB 7.5 and DePB showed higher level of GABA content than RB.”

Here’s further detail from the study:

Psycho-emotional status regulation of minigolf players (study)

Monday, September 11th, 2017

When it comes to sporting activities, the psycho-emotional state of the players can have a profound effect on their performance. What positive steps can be taken to enhance it? A number of strategies are currently available :

“[…] various ways and their combinations based on physiological reflexes are applied: breath holdings, relaxation of facial muscles, deep respiration, the arbitrariest synkineses, etc.”

How would such methods impact on the performance of, say, mini-golf players? A newly published study by Russian researchers Aleksey Korolkov, Evgeny Lysov and Oksana Frizen has referenced not only arbitrariest synkineses, but also the effects of aromas and music etc etc.

“It is established that the effect of influence of the functional music is comparable with effect of influence of an activating odorant and exhaustion. Significant distinctions in medians of Kerdo’s index by Vilkokson’s criterion for pair data at the level of a statistical significance are revealed statistically р =0.05. Besides, the effect of decrease in rate of game actions and increase of their stability after musical influence is established. “

See: About Ways of Psyhoemotional [sic] Status Regulation of Minigolf Players in MOJ Sports Med 2017, 1(1): 00004.

Note: There may still be time to book tickets for the World Minigolf Sport Federation Delegates Conference 2017, to be held in Nin (Croatia), Zaton Holiday Resort, September 17, 2017.