Rodrigo F. Fuck: The physical meaning of TOE tensors

July 31st, 2014

Rodrigo F. Fuck made a small stir in the geophysics community, as did Ilya Tsvankin, with publication of this study:

Analysis of the symmetry of a stressed medium using nonlinear elasticity,” Rodrigo Felício Fuck and Ilya Tsvankin, Geophysics, vol. 74, no. 5, 2009, pp. WB79-WB87. The authors write:

“Velocity variations caused by subsurface stress changes play an important role in monitoring compacting reservoirs and in several other applications of seismic methods. A general way to describe stress- or strain-induced velocity fields is by employing the theory of nonlinear elasticity, which operates with third-order elastic (TOE) tensors. These sixth-rank strain-sensitivity tensors, however, are difficult to manipulate because of the large number of terms involved in the algebraic operations.”

The second section of the paper is headlined “PHYSICAL MEANING OF TOE TENSORS”:

TOE-tensorsBONUS: On tensors of elasticity

BONUS (unrelated): Third order

 

 

The case for medical fist bumping, then and now

July 30th, 2014

Last year, 2013, medical researchers at West Virginia University published the study “Reducing pathogen transmission in a hospital setting. Handshake verses fist bump: a pilot study,” P.A. Ghareeb, T. Bourlai, W. Dutton, W.T. McClellan, Journal of Hospital Infection, vol. 85, no. 4, December 2013, pp. 321–323 (epub September 19, 2013). (We mentioned that here then.) That study says:

Handshaking is a known vector for bacterial transmission between individuals…. We have determined that implementing the fist bump in the healthcare setting may further reduce bacterial transmission between healthcare providers by reducing contact time and total surface area exposed when compared with the standard handshake.

This year, 2014, researchers at Aberystwyth University, Ceredigion, UK, published a study: “The fist bump: A more hygienic alternative to the handshake,” Sara Mela, David E. Whitworth, American Journal of Infection Control, vol. 42, 2014, pp. 916-7. The new study says:

We developed an experimental model to assay transfer of bacteria during greeting exchange, and show that transfer is dramatically reduced when engaging in alternative so-called dap greetings known as the high five and fist bump compared with a traditional handshake. Adoption of the fist bump as a greeting could substantially reduce the transmission of infectious disease between individuals.

The 2014 study does not cite the 2013 study. It’s yet another example of how medical knowledge can travel slowly, if at all.

The new study includes some near-poetic language, especially in this passage:

An experimental model and assay for bacterial transmission via physical contact was developed using standard microbiologic methods. A greeting donor immersed a sterile-gloved hand into a dense culture (2.4  109 CFU/mL) of nonpathogenic Escherichia coli and allowed a film of bacteria to dry onto the glove. A greeting was then exchanged with a sterile-gloved recipient.

The two co-authors cooperated in the making of a short educational video:

(Thanks to Ig Nobel Prize winner Mahadevan, and several other investigators, for bringing the new study to our attention.)

Fear of flying (amongst pilots)

July 30th, 2014

FlyingAlthough there are a good number of academic papers which examine ‘fear of flying’, [recent example] the number of scholarly dissertations which cover ‘fear of flying’ amongst a specific subset of air travellers – viz. pilots – is very low. Perhaps just one.

May we recommend the work of aviation practitioner, aviation historian, aviation philosopher, author and lecturer, Andrew Beniger – whose treatise : ‘Significant role of civilizations on fear of flying amongst flight deck’ was presented at the International Civil Aviation Organization’s 3rd World Conference on Fear of Flying, Montreal, 2007

 

Beginning of a new epidemic of penile amputations?

July 30th, 2014

A disputed penile amputation in Alabama, USA, faintly echoes an epidemic of penile amputations that happened in the 1970s in Thailand. WVTM television in Birmingham, Alabama, reports:

Attorney for doctors sued in penis amputation lawsuit seeks dismissal, calls case ‘baseless, irresponsible’

BIRMINGHAM, AL - Court documents filed today call into question allegations surrounding the amputation of a Birmingham man’s penis last month. The attorney representing the doctors sued in the case has filed for dismissal after testimonies reveal that neither performed a circumcision on the patient.

The lawsuit was filed July 22, 2014 and alleged that while in for a circumcision procedure that the plaintiff’s penis was amputated without his consent or explanation as to why it occurred….

The 2013 Ig Nobel Prize for public health was awarded to Kasian Bhanganada, Tu Chayavatana, Chumporn Pongnumkul, Anunt Tonmukayakul, Piyasakol Sakolsatayadorn, Krit Komaratal, and Henry Wilde, for the medical techniques described in their report “Surgical Management of an Epidemic of Penile Amputations in Siam” — techniques which they recommend, except in cases where the amputated penis had been partially eaten by a duck. [REFERENCE: "Surgical Management of an Epidemic of Penile Amputations in Siam," by Kasian Bhanganada, Tu Chayavatana, Chumporn Pongnumkul, Anunt Tonmukayakul, Piyasakol Sakolsatayadorn, Krit Komaratal, and Henry Wilde, American Journal of Surgery, 1983, no. 146, pp. 376-382.] At the Ig Nobel ceremony, Nobel laureate Eric Maskin read aloud the acceptance speech sent by the winners, who were unable to travel to Harvard.

BONUS: It is generally believed that, directly or indirectly, publicity about the Thai epidemic inspired the 1993 events in the United States that came to be known as “the Bobbitt case.”

UPDATE (July 30): Investigator Ivan Oransky alerts us to a newly published study:

Penile Prostheses and the Litigious Patient: A Legal Database Review,” Peter L. Sunaryo, Marc Colaco and Ryan Terlecki [pictured here], Journal of Sexual Medicine, epub July 29, 2014. The authors are at Rutgers New Jersey Medical School and Wake Forest School of Medicine. They examined 40 cases:

Terlecki-Ryan“There were 23 (57.5%) cases that were found in favor of the defendant, while 17 (42.5%) cases led to indemnity payment to the plaintiff including two cases (5.0%) that were settled out of court and 15 (37.5%) favoring the plaintiff in front of a jury. The mean settlement received was $335,500 compared with the mean indemnity award of $831,050 for verdicts decided in favor of the plaintiff (P = 0.68). The most common breach of duty was error in surgical decision making, present in 20 cases (48.8%). Informed consent was an issue in 13 filings (31.7%), and postoperative infection was seen in 13 cases (31.7%). In cases that identified the type of implant used, 58.3% were malleable implants, and 41.7% were inflatable devices.”

 

Like sound-cancelling headphones, kinda sorta, for odors

July 29th, 2014

If you know how noise-cancelling headphones work, you may have wondered whether the same kind of technical trick — producing your own vibrations that exactly cancel out the “noise” vibrations — might somehow work with smells. Twin-brother scientists Kush and Lav Varshney spent some time noodling on that notion. (Thanks to Martin Gardiner for telling me about the Varshneys.)

Kush (now at IBM, formerly at MIT) and Lav (now at the University of Illinois, formerly at IBM, and before that at MIT) have just presented a paper at a scientific conference — the IEEE International Workshop on Statistical Signal Processing — in Australia.

They call their somewhat-refined idea “active odor cancellation”….

—so begins another Improbable Innovation nugget, which appears in its entirety on BetaBoston.