Direct assessment of international consistency of standards for ground-level ozone: strategy and implementation toward metrological traceability network in Asia.

An international exercise to directly assess consistency of standards for ground-level ozone in East Asia was conducted as part of the East Asian Regional Experiment 2005 (EAREX 2005) in the framework of the Atmospheric Brown Clouds (ABC) project. Ten organizations collaboratively participated in the intercomparison. Four groups representing Japan, Korea, Hong Kong, and Taiwan made comparisons at the Gosan super observatory, Jeju Island, Korea, in March 2005, with ozone instruments calibrated to their national standards, and four Japanese groups made off-site comparisons with laboratory-level standards. All comparisons generally indicated good agreement with the standard reference photometer (SRP) 35, built by the National Institute of Standards and Technology (USA) and maintained by the National Institute for Environmental Studies (Japan). The assessment was expanded to measurement networks contributing to the World Meteorological Organization's Global Atmospheric Watch (WMO/GAW) program as part of off-site comparisons, and excellent agreement was achieved. These efforts contribute to propagating traceability of the national metrology standards among the atmospheric science community, to ensuring comparability of the existing ozone measurements, and to establishing an integrated network of air quality monitoring in Asia.

[Three-dimensional image of Adamkiewicz artery detected by using multidetector CT: preoperative assessment of thoraco-abdominal aortic aneurysm].

Images were obtained with the following parameter 0.5 sec/r, 1 mm collimation, pitch 3.5, 120 kV, 300 mA. One hundred ml of contrast material containing 350 mg I/ml was injected with a power injector (dual shot type) into an antecubital vein at a rate of 3.5 ml/sec (70 ml). Then remaining 30 ml and same volume of saline were infused at a rate of 1.5 ml/sec simultaneously. Twenty-five seconds after the injection, scan was performed from the level of L2 to T5 vertebrae. Transverse sections were reconstructed with a 1 mm thickness at 0.7 mm intervals. Imaging was done with multiplanar and curved planar reformations. In case of vertebral deformity, however, 3D images were made to depict the Adamkiewicz artery. In 141 patients, 107 (76%) Adamkiewicz arteries from the interverbral foramen to the hairpin-shaped union with the anterior spinal artery were visualized. Seventy-nine arteries of Adamkiewicz (73%) originated from the left side. Our method is useful for depicting Adamkiewicz artery.

A neo-Darwinian algorithm: asymmetrical mutations due to semiconservative DNA-type replication promote evolution.

Evolution is, in a sense, to resolve optimization problems. Our neo-Darwinian algorithm based on the mechanics of inheritance and natural selection uses double-stranded DNA-type genetic information to resolve the "knap-sack problem." The algorithm with asymmetrical mutations due to semiconservative DNA-type replication most effectively resolved the problem. Our results strongly suggest that disparity in mutations caused by the asymmetric machinery of DNA replication promotes evolution, in particular of diploid organisms with a high mutation rate, in a small population, and under strong selection pressure.