Best of PubMed #18

The muddy catfish.
Campbell BA.
J Pastoral Care Counsel. 2008 Spring-Summer;62(1-2):157-8.
PMID: 18572554

Don’t call me ‘four eyes’.
Springen K.
Newsweek. 2004 Oct 4;144(14):65-6.
PMID: 15516105

“Don’t look back; something might be gaining on you”.
Alpert JS.
Am J Med. 2009 Oct;122(10):885.
PMID: 19786151

Just don’t call me Mr. Mom.
Braiker B.
Newsweek. 2007 Oct 8;150(15):52-5.
PMID: 19178109

[Misunderstandings – man has 4 ears].
Niedermeyer M.
Aktuelle Urol. 2012 May;43(3):147-8. German.
PMID: 22950137

It wasn’t my fault….
Freeman JW.
S D Med. 2006 Nov;59(11):483-4.
PMID: 17180848

Make a stink.
Linton O.
Acad Radiol. 2008 Aug;15(8):1082.
PMID: 18620129

Computers, doctors, and toilet training.
Greene AR.
MedGenMed. 2000 Dec 11;2(6):E5.
PMID: 11335855

Apostrophe catastrophe.
McNamee D.
Lancet. 2006 Nov 11;368(9548):1636.
PMID: 17098068

Uncle Ernie and friends.
Goodman JR.
Cell Mol Biol (Noisy-le-grand). 2005 Sep 5;51(2):125-31.
PMID: 16178125

Curing lawyers.
Friedman JH.
Med Health R I. 2005 Apr;88(4):106.
PMID: 15974043

Questionless answers.
Carroll RJ.
J Indiana Dent Assoc. 2008 Fall;87(3):33.
PMID: 19248339

Hissy fits revividus.
Hall PF.
CMAJ. 1998 Dec 15;159(12):1478-9.
PMID: 9875255

[How to kill your own lecture].
Cervenka J.
Cesk Epidemiol Mikrobiol Imunol. 1991 Mar;40(2):115-9. Slovak.
PMID: 1827361

Note: This one was submitted by Robert Zinzen, new group leader at BIMSB, MDC – Thanks, Robert!
Law of Urination: all mammals empty their bladders over the same duration
Patricia J. Yang, Jonathan C. Pham, Jerome Choo, David L. Hu

The urinary system evolved to eject fluids from the body quickly and efficiently. Despite a long history of successful urology treatments in humans and animals, the physics of urination has received comparatively little attention. In this combined experimental and theoretical investigation, we elucidate the hydrodynamics of urination across five orders of magnitude in animal mass, from mice to elephants. Using high-speed fluid dynamics videos and flow-rate measurement at Zoo Atlanta, we discover the “Law of Urination”, which states animals empty their bladders over nearly constant duration of average 21 seconds (standard deviation 13 seconds), despite a difference in bladder volume from 100 mL to 100 L. This feat is made possible by the increasing urethra length of large animals which amplifies gravitational force and flow rate. We also demonstrate the challenges faced by the urinary system for rodents and other small mammals for which urine flow is limited to single drops. Our findings reveal the urethra evolved as a flow-enhancing device, enabling the urinary system to be scaled up without compromising its function. This study may help in the diagnosis of urinary problems in animals and in inspiring the design of scalable hydrodynamic systems based on those in nature.

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I am a science writer at the Max Delbrück Center for Molecular Medicine in Berlin, author of fiction and popular science books, an artist, and a professional musician who performs on the viola da gamba and Medieval and Renaissance stringed instruments. I edit manuscripts of all types and teach the full range of scientific communication skills. I am doing theoretical work in this subject - see for example

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