The tantalyzing fly

October 2nd, 2014

This 1919 animated cartoon by Max Fleisher shows many aspects of the motion of a fly. The Public Domain Review explains (basing its explanation on that in Wikipedia):

Max Fleischer (1883–1972) was a pioneer in the development of the animated cartoon and served as the head of Fleischer Studios. He brought such animated characters as Betty Boop, Koko the Clown, Popeye, and Superman to the movie screen and was responsible for a number of technological innovations. One of these was the Rotoscope, a technique in which animators trace over live-action film movement frame by frame. The technique was used to create his “Out of the Inkwell” series for Bray Studios.

BONUS: Ganson’s mechanical buzzing fly

“Tiny sea monkeys influence oceanic currents and waves”

October 1st, 2014

This week’s Headline of the Week appears in the Delhi Daily News, on October 1, 2014:

Tiny sea monkeys influence oceanic currents and waves

Tiny sea monkeys, which are actually a kind of shrimp, create giant ocean currents every evening after sunset.

Even though these sea monkeys are small in size they are given the name because their tail resembles a monkey’s tail.

Sea monkeys are also known as brine shrimp (Artemia salina) may contribute about a trillion watts, or a terawatt, of power to the surrounding ocean, churning the seas with the same power as the tides, the researchers said….

The article refers to the less colorfully worded study:

Induced drift by a self-propelled swimmer at intermediate Reynolds numbers,” Janna C. Nawroth and John O. Dabiri, Physics of Fluids, (1994-present) 26, no. 9 (2014): 091108. The researchers are both at Caltech.

(Thanks to investigator Gary Dryfoos for bringing this to our attention.)

Shoelaces — the trials of cooperatively tying them with other people

October 1st, 2014

Primary instructor Michael J. Crites and professor Jamie C. Gorman of the Human Factors Psychology dept. at Texas Tech University Lubbock, US, have investigated (experimentally) some of the difficulties of shoelace tying – with two hands, one hand, and with someone else’s hand. See: Learning to Tie Well with Others : Bimanual vs. Intermanual Coordination during Shoe-tying in Proceedings of the Human Factors and Ergonomics Society Annual Meeting September 2013 vol. 57 no. 1 1377-1381
Shoelace-Tying

“A shoe-tying paradigm was developed to examine mode effects and motor learning functions when people are asked to handle a familiar object (e.g., tying a shoe) using an unfamiliar coordination mode (e.g., tying a shoe with another person). Dyads first tied a shoe apparatus using their own two hands (“bimanual”) for 10 trials and then tied the shoe as a dyad, each person using one hand (“intermanual”) for 20 trials. Finally, participants tied the shoe bimanually for another 10 trials. Previous research has indicated that intermanual is faster than bimanual, but those experiments examined novel tasks performed by novices. For this familiar task, results revealed that participants were significantly slower in the intermanual mode compared to either set of bimanual trials, and participants were significantly faster in the second set of bimanual trials than the first. Unlike mode effects for novel tasks with novice participants, the intermanual mode was slowest, though intermanual performance may have enhanced subsequent bimanual performance. Previous research on motor learning suggests an exponential function describes acquisition of a novel skill, whereas a power law describes persistent motor learning. Analyses revealed that dyads exhibited a power law function over both the first set of bimanual trials and the intermanual trials. That finding suggests that participants were not learning a new coordination skill in the intermanual mode but may have transferred persistent, bimanual shoe-tying skill to the novel mode. Theoretical and practical implications of acquisition of a novel coordination mode for a familiar task are described. “

Also see, a previous paper: Are Two Hands (From Different People) Better Than One? Mode Effects and Differential Transfer Between Manual Coordination Modes in: Human Factors: The Journal of the Human Factors and Ergonomics Society August 2013 vol. 55 no. 4, pp. 815-829

 

The rise (to 85,000 feet) and fall of Walter White

September 30th, 2014

Kayla Reed, writing for AV Club, gives some of the background to this video:

In the year since Breaking Bad bled off the airwaves, fans and stars alike have been reveling in its wake. One of the more creative homages comes courtesy of TV Tag, whose staff gathered a crew to send a Walter White bobblehead beyond the atmosphere and back again. The video below features a timelapse of the construction, launch, and travels of Mr. White and his vessel, whose six-hour journey took him 250 miles and reached a maximum altitude of 85,000 feet.

(Thanks to investigator Jane Hill for bringing this to our attention.)

BONUS: The chemistry of Breaking Bad, analyzed

Decline of pubic lice linked to removal of pubic hair, again

September 30th, 2014

Schaamluis_Toonstra1_edited-1Again researchers in the UK took the lead in pubic lice research. After Nicola Armstrong and Janet Wilson of the Department of Genitourinary Medicine, The General Infirmary at Leeds, posed the intriguing question ‘Did the Brazilian kill the pubic louse’ in 2006, many feared the rapid disappearance of the primary habitat – human pubic hair – would bring down the numbers of Pthirus pubis, or at least the number of cases of pubic lice infestations seen by medical professionals.

Now a follow-up study, carried out by Shamik Dholakia, Jonathan Buckler, John Paul Jeans, Andrew Pillai, Natasha Eagles and Shruti Dholakia at the Milton Keynes General Hospital, Buckinghamshire, UK, based on 3850 returned questionnaires over a period of ten years, confirmed the decreasing incidence of pubic lice infestations and links this demise strongly to pubic hair removal practices. In their report ‘Pubic Lice: An Endangered Species?’ published recently in Sexually Transmitted Diseases 41(6): 388-391, they state, firmly:

Results: A significant and strong correlation between the falling incidence of pubic lice infections and increase in pubic hair removal was observed.
Conclusions: The increased incidence of hair removal may lead to atypical patterns of pubic lice infestations or its complete eradication as the natural habitat of this parasite is destroyed.

However, they still see a future for the species:

As culture and practice changes, we may see a changing atypical pattern of pubic lice infestations, as they try to colonize other habitats such as chest or eyebrow hair.

BONUS: A well preserved sample of Dutch specimens of Pthirus pubis, kept in the collection of the Natural History Museum Rotterdam, from 1949 when they had nothing to fear:
NMR_pubic_lice_1949
And here is some history: my own hunt for pubic lice specimens, in 2007.