Cloudy Skies 



Cars, planes, trucks, and trains are infamous 

 air polluters, but ships are often overlooked. 

 Yet increased shipping in recent decades 

 has led to a dramatic rise in ships' fuel con- 

 sumption, which more than quadrupled be- 

 tween 1950 and 2001. Now, the effects of 

 the ships' correspondingly increased emis- 

 sions have been detected in clouds. Hint: 

 they aren't wisps of black soot. 



Cloud droplets form around airborne par- 

 ticles, which engines and factories that lack 

 adequate filters emit in abundance. More 

 droplets make for denser, higher clouds. 

 Because dense, polluted clouds reflect more 

 light, and higher clouds have cooler tops than 

 normal clouds do, the effects of pollution can 

 be measured by visible-light and infrared sen- 

 sors aboard satellites. 



Abhay Devasthale, a remote-sensing spe- 

 cialist at the University of Hamburg in Ger- 

 many, and two colleagues published data 

 that highlight ship pollution in the air above 

 the English Channel and its three dingiest 

 harbors. Between 1997 and 2002, Dev- 

 asthale reports, clouds there became about 



A Very Dry White 



The ancient Egyptians loved their wine. 

 They buried their dead with wine-filled am- 

 phorae, or clay vessels, to ensure a com- 

 fortable afterlife, and they painted scenes 

 of viticulture and winemaking on the walls 

 of tombs. But what varieties did they enjoy? 

 Written records and the dark color of 



■ 



Ship pollutes the air in Ushuaia, at the southern tip of Argentina. 



Egyptian winemaking, tomb painting, 1400 B.C. 



1.5 percent more reflective, and the tem- 

 perature of their tops dropped by about 

 three degrees Fahrenheit. Meanwhile, over 

 nearby inland areas the trend was reversed. 

 Thus, despite successful European efforts 

 to reduce land-based emissions, ship ex- 

 haust remains a troubling source of air pol- 

 lution. {Geophysical Research Letters 

 33:L02811, 2006) 



— Stephan Reebs 



tomb-wall grapes suggest they drank reds. 

 But now there's evidence that whites were 

 popular, too. 



Maria Rosa Guasch-Jane, an Egyptolo- 

 gist, and Rosa M. Lamuela-Raventos, a food 

 and nutrition scientist, both at the University 

 of Barcelona, Spain, and their colleagues an- 

 alyzed residues in six of the twenty-six am- 

 phorae from King Tutankhamun's tomb. The 

 team detected tartaric acid, which occurs 

 naturally only in grapes, in each of the 

 residues. Dark residue in one amphora in- 

 cluded syringic acid, which is derived from 

 the main pigment that gives red grapes 

 their color. Yellowish residues in the other 

 five amphorae lacked syringic acid, suggest- 

 ing they were probably the remnants of 

 white wines. 



The ancient Egyptians appear to 

 have valued white wine as much as 

 red. King Tut was buried with three 

 amphorae near his sarcophagus; two 

 of them held red wine and the third 

 held white. (Journal of Archaeological 

 Science, forthcoming) 



— Rebecca Kessler 



Millipede Soccer 



For the coati, a small mammal that ranges 

 from the southwestern United States to 

 South America, few snacks are more tempt- 

 ing than a juicy millipede. But something un- 

 pleasant stands in the way of an easy meal: 

 evolution has equipped the millipede with 

 chemical defenses that deter most preda- 

 tors. What's a coati to do? On first encounter, 

 it rolls the many-legged arthropod between 

 its front paws. The millipede responds in a 

 panic, pumping out poisons as fast as it can. 

 Soon, though, the supply of poisons is ex- 

 hausted. Then, the coati simply drags the mil- 

 lipede through the soil, effectively wiping off 

 the toxins. Voila! It's snack time. 



But there's more. According to a study 

 led by Paul J. Weldon, a biologist at the 

 Smithsonian Institution in Front Royal, Vir- 

 ginia, the noxious chemicals secreted by irri- 

 tated millipedes actually trigger the coati's 

 prey-rolling behavior. The coati's response is 

 so "hard wired" that even a stick dipped in 

 the millipede's defensive chemicals elicits 

 the behavior. The coati has won this evolu- 

 tionary arms race in more ways than one. 

 {Naturwissenschaften 93:14-6, 2006) 



— Nick W. Atkinson 



Coati plays with its food. 



April 2006 NATURAL HISTORY 



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