[1] Considerable uncertainties remain in the global pattern of diurnal variation in stratospheric ozone, particularly lower to middle stratospheric ozone, which is the principal contributor to total column ozone. The Superconducting Submillimeter-Wave LimbEmission Sounder (SMILES) attached to the Japanese Experiment Module (JEM) on board the International Space Station (ISS) was developed to gather high-quality global measurements of stratospheric ozone at various local times, with the aid of superconducting mixers cooled to 4K by a compact mechanical cooler. Using the SMILES dataset, as well as data from nudged chemistry-climate models (MIROC3.2-CTM and SD-WACCM), we show that the SMILES observational data have revealed the global pattern of diurnal ozone variations throughout the stratosphere. We also found that these variations can be explained by both photochemistry and dynamics. The peak-to-peak difference in the stratospheric ozone mixing ratio (total column ozone) reached 8% (1%) over the course of a day. This variation needs to be considered when merging ozone data from different satellite measurements and even from measurements made using one specific instrument at different local times.
In order to develop novel antiasthmatic agents based on a new mechanism of action, a series of 3-substituted 5-amino-1-[(methylamino)(thiocarbonyl)]-1H-1,2,4-triazole derivatives were synthesized and evaluated in a model in which eosinophilia was induced in the airway through intravenous (iv) injection of Sephadex particles on days 0, 2, and 5. After screening of several hundred derivatives, we finally identified the highly potent eosinophilia inhibitor 5-amino-3-(4-chlorophenyl)-1-[(methylamino)(thiocarbonyl)]-1H-tria zole (23c, GCC-AP0341), which had ID50 values of 0.3 and 0.07 mg/kg when administered orally (os) and intraperitoneally (ip), respectively. This compound showed complete inhibition of the hypersensitivity induced by ascaris inhalation at an ip dose of 1 mg/kg as well as low toxicity, with an LD50 value of > 2.0 g/kg in mice. Extensive study of its mechanism of action revealed that 23c inhibited eosinophil survival induced by interleukin-5 (IL-5), but had little or no effect on leukotriene D4 (LTD4) or platelet-activating factor (PAF)-induced responses. Taken together, these results suggest 23c as a novel candidate for the treatment of chronic asthma. Further studies are now underway.
A statistical study is made of the interannual variability of the northern winter stratospheric circulation in connection with the equatorial quasi-biennial oscillation (QBO) and the solar cycle, by using the 37-year stratospheric dataset of the Freie Universitat Berlin and the 31-year NMC global data.During the period 196263-197778, analyzed first by Holton and Tan (1980, referred to as HT), the polar-night jet is stronger in the W (westerly) than in the E (easterly), as was mentioned by Holton and Tan (1980). However, the difference between the W and the E is barely significant in 'the latter half period ' (197879-199394). When the whole period is classified into two groups defined as 'Min' and 'Max' with respect to the intensity of the 10.7-cm solar flux, it is clearly shown that the late-winter jet in the W is much stronger than in the E (the value of Student's t test exceeds 6) in the Min group, whereas it is no stronger in the Max group. The reason why the result from the HT period resembles that from the Min is probably because the HT period includes two solar minima and one maximum. In early winter, the circulation seems to be correlated with the QBO irrespective of the solar cycle. This difference between early and late winter suggests that the equatorial QBO influences the extratropical circulation in early winter and that the solar cycle modifies it in late winter.An extensive analysis of wave components is also made. The result from the Min is similar to that of the HT period, and the difference between the W and the E is larger than in the HT period. In late winter, the result from the Max is the inverse of the Min result.Finally, the occurrence of major warmings is shown to be related significantly to the QBO and the solar cycle. Such a relationship is clearly illustrated by plotting the occurrence of the major warming onto a 2D phase space of the solar flux and the equatorial wind.
We evaluated the degree of selfing and inbreeding depression at the seed and seedling stages of a threatened tropical canopy tree, Neobalanocarpus heimii, using microsatellite markers. Selection resulted in an overall decrease in the level of surviving selfed progeny from seeds to established seedlings, indicating inbreeding depression during seedling establishment. Mean seed mass of selfed progeny was lower than that of outcrossed progeny. Since the smaller seeds suffered a fitness disadvantage at germination in N. heimii, the reduced seed mass of selfed progeny would be one of the determinants of the observed inbreeding depression during seedling establishment. High selfing rates in some mother trees could be attributed to low local densities of reproductive individuals, thus maintenance of a sufficiently high density of mature N. heimii should facilitate regeneration and conservation of the species.
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