Including sheath effects in the interpretation of planar retarding potential analyzer's low-energy ion data.

The interpretation of planar retarding potential analyzers (RPA) during ionospheric sounding rocket missions requires modeling the thick 3D plasma sheath. This paper overviews the theory of RPAs with an emphasis placed on the impact of the sheath on current-voltage (I-V) curves. It then describes the Petite Ion Probe (PIP) which has been designed to function in this difficult regime. The data analysis procedure for this instrument is discussed in detail. Data analysis begins by modeling the sheath with the Spacecraft Plasma Interaction System (SPIS), a particle-in-cell code. Test particles are traced through the sheath and detector to determine the detector's response. A training set is constructed from these simulated curves for a support vector regression analysis which relates the properties of the I-V curve to the properties of the plasma. The first in situ use of the PIPs occurred during the MICA sounding rocket mission which launched from Poker Flat, Alaska in February of 2012. These data are presented as a case study, providing valuable cross-instrument comparisons. A heritage top-hat thermal ion electrostatic analyzer, called the HT, and a multi-needle Langmuir probe have been used to validate both the PIPs and the data analysis method. Compared to the HT, the PIP ion temperature measurements agree with a root-mean-square error of 0.023 eV. These two instruments agree on the parallel-to-B plasma flow velocity with a root-mean-square error of 130 m/s. The PIP with its field of view aligned perpendicular-to-B provided a density measurement with an 11% error compared to the multi-needle Langmuir Probe. Higher error in the other PIP's density measurement is likely due to simplifications in the SPIS model geometry.

Plasma pattern of adrenocorticotropin and cortisol during electroconvulsive therapy in patients with major depressive illness.

Thirty-three patients with major depressive illness were treated with electroconvulsive therapy (ECT) and plasma adrenocorticotropin (ACTH), and cortisol levels were measured 30 min before and 1, 5, 15, 30 and 60 min after ECT. There was an immediate release of ACTH with a maximum after 5 min. The maximum cortisol plasma levels were measured 30 min after ECT. No change in ACTH and cortisol concentrations was seen in control experiments when the patients received only anaesthesia. ACTH release was seen in patients treated with ECT in the morning and in the evening. In 15 patients the levels were studied at the first and sixth (last) ECT. ACTH and cortisol levels were significantly higher after the first ECT as compared with the sixth. This alteration in ACTH release might reflect ECT-induced changes in the central monoaminergic transmission with stimulation of beta-adrenergic pathways leading to inhibition of ACTH-release.