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Abstract: Ground-based in-situ measurements were performed to investigate the spectral optical properties and hygroscopicity of light scattering and absorbing aerosols in pollution and dust plumes in Northeast Asia. The scattering Ångström exponents of pollution plumes are high, ranging from 0.8 to 1.8, because light scattering aerosols consist of relatively fine particles such as sulfate, nitrate, ammonium and carbonaceous particles. Pollution case having high organic carbon (OC) exhibits a relatively high absorption Ångström exponent (AAE), in the range of 1.0–1.5 due to the absorption by refractory OC at near-UV spectral region. Among the different pollution cases, the AAE is the highest in a polluted dust plume; this can be attributed to the strong wavelength dependence of light absorption by dust particles. The mass absorption cross section (MAC), which represents the ability of light-absorbing aerosols to absorb a photon, is 4.2–8.3 m2 g−1, and it is high when black carbon is mixed with OC and dust particles. The MAC decreases with increasing relative humidity, especially for pollution plume with a high OC content and for dust plume. Under humid conditions, hygroscopic chemical species can absorb water vapor, thus growing in size and enhancing aerosol light scattering, but the MAC decreases because of the possible shielding effects of absorbing aerosols with water uptake. [Copyright &y& Elsevier]

Time variations of lightning activity in the three main tropical thunderstorm centers located in the Maritime Continent (Pakistan, India, Southeast Asia, Indonesia, and Australia), Africa, and the Americas are analyzed using a lightning activity index IRS, which is calculated from the resonances of magnetic field in the extremely low frequency range—the Schumann resonances—which were observed at Hylaty station (Poland) in the time interval July 2005–May 2006. Power spectrum analysis of the IRS series is carried out for this time interval. The annual and semiannual variations are shown in all of the series together with the following characteristic periodicities: 45 (Madden–Julian oscillation), 17.6, 13.5, and 4.8 days, seen mainly in the series describing the lightning activity of the Maritime Continent. In addition, maps of the dynamical power spectrum are constructed. They present variability both in the values of characteristic periods 26–30, 17–22, 12–14, 9–10, and 5–7 days and in their duration. During the studied time interval, according to these indices, the African center was the most active, whereas the American and Maritime Continent centers showed a similar level of activity. The largest differences among the centers were observed in the summer months in the Northern Hemisphere. [ABSTRACT FROM AUTHOR]

Neuromyelitis optica (NMO) can be distinguished from MS by clinical, radiological and serological findings, especially the tendency for spinal cord lesions to be longer than 3 vertebral segments during acute attacks and the presence of aquaporin-4 autoantibodies in NMO. The spectrum of NMO is broader than previously realized and includes recurrent myelitis, recurrent optic neuritis, certain cerebral presentations, including intractable vomiting and posterior reversible encephalopathy. It may coexist with other systemic autoimmune diseases, including systemic lupus erythematosus and Sjogren's syndrome. Whether NMO has a predilection for individuals of Asian ancestry or whether there are differences between NMO and Asian optic-spinal MS other than arbitrary definitions remains to be clarified. Further epidemiological studies using comparable diagnostic criteria, radiological studies and serological tests are required. [ABSTRACT FROM AUTHOR]