.[1] This paper compares results from a whole atmosphere-ionosphere coupled model, GAIA, with the COSMIC and TIMED/SABER observations during the 2008/2009 northern winter season. The GAIA model has assimilated meteorological reanalysis data by a nudging method. The comparison shows general agreement in the major features from the stratosphere to the ionosphere including the growth and decay of the major stratospheric sudden warming (SSW) event in 2009. During this period, a pronounced semidiurnal variation in the F region electron density and its local-time phase shift similar to the previous observations are reproduced by the model and COSMIC observation. The model suggests that the electron density variation is caused by an enhanced semidiurnal variation in the E Â B drift, which is probably related to an amplified semidiurnal migrating tide (SW2) in the lower thermosphere. The model and TIMED/SABER observation show that the SW2 tide amplifies at low latitudes from the stratosphere to the thermosphere as well as the phase variation. Possible mechanisms for the SW2 variability in the low latitude stratosphere could be the change of its propagation condition, especially the (2, 2) mode, due to changing zonal background wind and meridional temperature gradient, and/or an enhancement of its source due to redistribution of stratospheric ozone. Present results also show a prominent long-term variation of the terdiurnal migrating component (TW3) in the ionosphere and atmosphere.
[1] Using the data from the NOAA and Exos-D satellites during the 3 November 1993 magnetic storm, the dynamic behavior of electrons with energies from a few tens of kiloelectronvolts to a few and its relation to plasma waves were examined. After the late main phase, relativistic electron flux started to recover from the heart of the outer radiation belt, where the cold plasma density was extremely low, and intense whistler mode chorus emissions were detected. The phase space density showed a peak in the outer belt, and the peak increased gradually. The simulation of the inward radial diffusion process could not reproduce the observed energy spectrum and phase space density variation. On the other hand, the simulated energy diffusion due to the gyroresonant electronwhistler mode wave interactions, under the assumption of the Kolmogorov turbulence spectrum, could generate the relativistic electrons without the flux transport from the outer region. The present study suggested that the seed population of relativistic electrons, which appeared in the heart of the outer radiation belt during the late main phase, was the ring current electrons injected from the plasma sheet, and that the acceleration by whistler mode chorus via gyroresonant wave-particle interactions outside the plasmapause could play an important role to generate the relativistic electrons.
[1] We study the effect of electromagnetic ion cyclotron (EMIC) wave scattering on radiation belt electrons during the large geomagnetic storm of 21 October 2001 with minimum Dst = À187 nT. We use our global physics-based model, which solves the kinetic equation for relativistic electrons and H + , O + , and He + ions as a function of radial distance in the equatorial plane, magnetic local time, energy, and pitch angle. The model includes time-dependent convective transport and radial diffusion and all major loss processes and is coupled with a dynamic plasmasphere model. We calculate the excitation of EMIC waves self-consistently with the evolving plasma populations. Particle interactions with these waves are evaluated according to quasi-linear theory, using diffusion coefficients for a multicomponent plasma and including not only field-aligned but also oblique EMIC wave propagation. The pitch angle diffusion coefficients increase from 0°to $60°during specific storm conditions. Pitch angle scattering by EMIC waves causes significant loss of radiation belt electrons at E ! 1 MeV and precipitation into the atmosphere. However, the relativistic electron flux dropout during the main phase at large L ! 5 is due mostly to outward radial diffusion, driven by the flux decrease at geosynchronous orbit. We show first results from global simulations indicating significant relativistic electron precipitation within regions of enhanced EMIC instability, whose location varies with time but is predominantly in the afternoon-dusk sector. The precipitating electron fluxes are usually collocated with precipitating ion fluxes but occur at variable energy range and magnitude. The minimum resonant energy increases at low L and relativistic electrons at E 1 MeV do not precipitate at L < 3 during this storm.
D-Amino acids, the enantiomers of L-amino acids, are increasingly recognized as novel biomarkers. Although the amounts of D-amino acids are usually very trace in human, some of them have sporadically been detected in blood from patients with kidney diseases. This study examined whether multiple chiral amino acids would be associated with kidney functions, comorbidities, and prognosis of chronic kidney disease (CKD) by enantioselective analyses of all chiral amino acids with a micro-two-dimensional high-performance liquid chromatograph (2D-HPLC)-based analytical platform. 16 out of 21 D-amino acids were detected in plasma from 108 CKD patients in a longitudinal cohort. The levels of D-Ser, D-Pro, and D-Asn were strongly associated with kidney function (estimated glomerular filtration ratio), the levels of D-Ala and D-Pro were associated with age, and the level of D-Asp and D-Pro were associated with the presence of diabetes mellitus. D-Ser and D-Asn were significantly associated with the progression of CKD in mutually-adjusted Cox regression analyses; the risk of composite end point (developing to ESKD or death before ESKD) was elevated from 2.7- to 3.8-fold in those with higher levels of plasma D-Ser and D-Asn. These findings identified chiral amino acids as potential biomarkers in kidney diseases.
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