Extreme deuterium excesses in ultracarbonaceous micrometeorites from central Antarctic snow.

Primitive interplanetary dust is expected to contain the earliest solar system components, including minerals and organic matter. We have recovered, from central Antarctic snow, ultracarbonaceous micrometeorites whose organic matter contains extreme deuterium (D) excesses (10 to 30 times terrestrial values), extending over hundreds of square micrometers. We identified crystalline minerals embedded in the micrometeorite organic matter, which suggests that this organic matter reservoir could have formed within the solar system itself rather than having direct interstellar heritage. The high D/H ratios, the high organic matter content, and the associated minerals favor an origin from the cold regions of the protoplanetary disk. The masses of the particles range from a few tenths of a microgram to a few micrograms, exceeding by more than an order of magnitude those of the dust fragments from comet 81P/Wild 2 returned by the Stardust mission.

[Fractures of the odontoid process. 94 cases, 61 treated by arthrodesis]. / Les fractures de l'apophyse odontoïde 94 cas dont 61 traités par arthrodèse

The authors have reviewed 94 cases of fractures of the odontoid process, 21 of the with neurological signs. The conclusions were as follows: 1) Conservative treatment in 26 cases led to 9 non-unions; 2) 27 recent fractures were operated on (arthrodesis) with 24 fusions; 3) 54 cases were treated more than 30 days after the accident: 15 ot them demonstrated neurological involvement, 34 of them were operated on; 4) The surgical technique is fully described, usually the operation aimed at fusing C1 to C2; 5) One patient died, none was aggravated, all were somewhat improved on the neurological standpoint; 6) On a functional standpoint neck mobility was less decreased after conservative treatment than after cervical fusion.