Archive for 'Boys Will Be Boys'

Surprising end-results from prize-winning urination-duration researchers

Tuesday, April 25th, 2017

A new study called “Hydrodynamics of Defecation,” published in the research journal Soft Matter, emerges from the same laboratory at Georgia Tech that produced the Ig Nobel Prize-winning study “Duration of Urination Does Not Change With Body Size.” The earlier, urination study was published in the Proceedings of the National Academy of Sciences.

Co-authors Patricia Yang and David Hu shared the Ig Nobel Prize for biology, in the year 2015, as did their urination co-authors Jonathan Pham and Jerome Choo. In the new, defecation study, Yang and Hu are joined in co-authorship by Morgan LaMarca, Candice Kaminski, and Daniel I Chu.

Here’s detail from the new study:

The above three-part illustration shows:

(A) The relationship between body mass M and the mass flow rates of food intake and excreted feces. Symbols represent experimental measurements, and dashed lines represent best fits to the data. (B) Schematic of the flow rate of energy in mammals. (C) Pie chart of the distribution of energy intake.

The authors introduce the underlying mathematics of their work with another simple illustration. They explain:

We present a mathematical model for defecation. Our system consists of a pipe whose length consists of the rectum and the colon, illustrated [here]. We model cylindrical feces of diameter D and total length L, consisting of several pieces joined like sausages. The walls of the cylinder are coated with a mucus layer of thickness h, which is considerably less than D. We parameterize the motion of feces and mucus using cylindrical coordinates…  in which z represents the horizontal direction along the cylinder and r the radial direction from the center of the feces to the walls.

The paper reduces the entire flow of its argument into this dense nugget:

Animals discharge feces within a range of sizes and shapes. Such variation has long been used to track animals as well as to diagnose illnesses in both humans and animals. However, the physics by which feces are discharged remain poorly understood. In this combined experimental and theoretical study, we investigate the defecation of mammals from cats to elephants using the dimensions of large intestines and feces, videography at Zoo Atlanta, cone-on-plate rheological measurements of feces and mucus, and a mathematical model of defecation. The diameter of feces is comparable to that of the rectum, but the length is double that of the rectum, indicating that not only the rectum but also the colon is a storage facility for feces. Despite the length of rectum ranging from 4 to 40 cm, mammals from cats to elephants defecate within a nearly constant duration of 12 ± 7 seconds.

The Ig Nobel Prize citation for the earlier, urination study, explains that that earlier study tested “the biological principle that nearly all mammals empty their bladders in about 21 seconds (plus or minus 13 seconds).” The results of the new study, combined with the results of the new study, provide an enriched understanding of how mammalian output functions relate to time.

UPDATE: New Scientist magazine made a short video (and did a writeup) about this, complete with background excretion music:

UPDATE: Co-authors Patricia Yang and David Hu write about their research, in The Conversation: “Physics of poo: Why it takes you and an elephant the same amount of time

The Cultural Meaning of ‘Everybody, Let’s Tighten the Anus’

Wednesday, March 1st, 2017

What depths has the anus song? This study takes a look:

‘Everybody, Let’s Tighten the Anus’: Exploring the Social and Cultural Meaning of a Korean Folksong,” Joonseong Lee [pictured here], Journal of Media and Religion, vol. 11, no. 4, 2012, pp. 216-230. The author, at California State University San Marcos, explains:

“The immanent approach to the anus song with the view of Eastern qi philosophy provides this research with a cogent theoretical framework for energy spirituality, which is constructed in the practice of breathing, including anus breathing or anal sphincter exercise.”

Here is a performance of the song:

BONUS (possibly related): Song on the anus.

“Learning to love the secret language of urine”

Tuesday, February 28th, 2017

Dr. Jonathan Reisman writes, in the Washington Post, about his professional love affair with a body fluid:

Many physicians are actively drawn to a particular bodily fluid, intrigued by its unique diagnostic mysteries. Each fluid that runs through the body is a language in which diseases speak to physicians, telling them what is wrong with a patient. And specializing means becoming fluent in one specific fluid’s dialect, learning to interpret its colors, textures and consistencies, and spending a career pondering its secrets.

As a medical student, I saw that a bodily fluid could shape a career. And though I resisted settling on just one (I remain a generalist), I have always been partial to pee….

Sensation Seeking, Sports Cars, and Hedge Funds (new study)

Thursday, February 16th, 2017

“The emerging [hedge fund] manager who goes out and buys a fancy sports car right off the bat is someone you probably want to avoid.”

– informed an article in Business Insider (Singapore), February 2016. But was the statement measurably valid? To find out Stephen Brown, Yan Lu, Sugata Ray and Melvyn Teo set up a research project to empirically investigate the so-called ‘Red Ferrari Syndrome’.

An analysis of 48,778 hedge funds (with reference to the automobile preferences of the funds’ managers, and the funds’ results over time) showed striking results.

“The empirical results are striking. We find that hedge fund managers who purchase performance cars take on more investment risk than do fund managers who eschew performance cars. Specifically, sports car drivers deliver returns that are 1.80 percentage points per annum more volatile than do non-sports car drivers. This represents a 16.61 percent increase in volatility over that of drivers who shun sports cars. Similarly, drivers of high horsepower and high torque automobiles exhibit 1.14 and 1.25 percentage points per annum more volatility, respectively, in the funds that they manage than do drivers of low horsepower and low torque automobiles.”

See: Sensation Seeking, Sports Cars, and Hedge Funds NYU Working Paper, December 2016.

The photo shows the new, red, Ferrari J50

The dismaying danger of buying perfume as a gift

Sunday, February 12th, 2017

Craig Roberts, at the University of Stirling, warns you, based on his research, that there are “more reason to choose fragrances carefully“:

there is no one-scent-fits-all effect here. Different fragrances suit different people. In a study with my Czech colleague [Ig Nobel Prize winner] Jan Havlíček, we found that some people get this spectacularly wrong. While overall artificial fragrances improve the smell of their natural body odour, for some people, their armpit odour smells worse when they use their chosen fragrance – they have selected one that clearly doesn’t blend well with their own odour. More recently, my excellent ex-student Caroline Allen has shown that the right fragrance choice can emphasise the distinctiveness of our underlying body odour.

Now, Caroline has found something really very interesting about the effects of fragrances. Whereas the smell of unperfumed armpits (relatively masculine or feminine) predicts how our faces look (relatively masculine or feminine), this relationship disappears when men use fragrance. The relationship is maintained in the case of women’s smell and faces. And it disappears, in men, in an interesting way

DNA Cologne, invented by Bijan of Beverly Hills. The inventor was awarded the 1995 Ig Nobel Prize in chemistry.

DNA Cologne, invented by Bijan of Beverly Hills. The inventor was awarded the 1995 Ig Nobel Prize for chemistry.

In a recent Improbable Research podcast, Jean Berko Gleason explores the Roberts/Havlíček team’s garlic/armpit-smell study, with glee and more than a soupçon of disgust.