16 research outputs found
Radio Aurora Explorer: Mission science and radar system
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95507/1/rds5936.pd
First measurements of radar coherent scatter by the Radio Aurora Explorer CubeSat
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95350/1/grl29342.pd
Magnetic aspect sensitivity of high‐latitude E region irregularities measured by the RAX‐2 CubeSat
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106761/1/jgra50801.pd
Imaging radar observations of Farley Buneman waves during the JOULE II experiment
Vector electric fields and associated <I><B>E</B></I>&times;<I><B>B</B></I> drifts measured by a sounding rocket in the auroral zone during the NASA JOULE II experiment in January 2007, are compared with coherent scatter spectra measured by a 30 MHz radar imager in a common volume. Radar imaging permits precise collocation of the spectra with the background electric field. The Doppler shifts and spectral widths appear to be governed by the cosine and sine of the convection flow angle, respectively, and also proportional to the presumptive ion acoustic speed. The neutral wind also contributes to the Doppler shifts. These findings are consistent with those from the JOULE I experiment and also with recent numerical simulations of Farley Buneman waves and instabilities carried out by Oppenheim et al. (2008). Simple linear analysis of the waves offers some insights into the spectral moments. A formula relating the spectral width to the flow angle, ion acoustic speed, and other ionospheric parameters is derived
Enhanced ion acoustic lines due to strong ion cyclotron wave fields
The Fast Auroral Snapshot Explorer (FAST)
satellite detected intense and coherent 5–20 m electric field
structures in the high-latitude topside auroral ionosphere between
the altitudes of 350 km and 650 km. These electric fields
appear to belong to electrostatic ion cyclotron (EIC) waves in
terms of their frequency and wavelengths. Numerical simulations of
the response of an electron plasma to the parallel components of
these fields show that the waves are likely to excite a
wave-driven parallel ion acoustic (IA) instability, through the
creation of a highly non-Maxwellian electron distribution function,
which when combined with the (assumed) Maxwellian ion
distribution function provides inverse Landau damping. Because the
counter-streaming threshold for excitation of EIC waves is well
below that for excitation of IA waves (assuming Maxwellian
statistics) our results suggest a possible two step mechanism
for destabilization of IA waves. Combining this simulation result
with the observational fact that these EIC waves share a
common phenomenology with the naturally enhanced IA lines (NEIALS)
observed by incoherent scatter radars, especially that they both
occur near field-aligned currents, leads to the proposition that
this two-step mechanism is an alternative path to NEIALS
Executive Functioning in Subtypes of Attention Deficit Hyperactivity Disorder
Introduction: This study aims to evaluate executive functions (EF), such as inhibition, planning, working memory, and set shifting, in children with attention deficit hyperactivity disorder (ADHD) by comparing three ADHD subtype groups (ADHD-Inattentive, ADHD-Combined, and ADHD-Comorbid) and a normal control group
The effects of dexamethasone and minocycline alone and combined with N-acetylcysteine and vitamin E on serum matrix metalloproteinase-9 and coenzyme Q10 levels in aflatoxin B1 administered rats
This study aimed to determine the effects of dexamethasone and minocycline alone and combined treatment with N-acetylcysteine (NAC) and vitamin E on serum coenzyme Q10 (CoQ10) and matrix metalloproteinase-9 (MMP-9) levels in rats administered aflatoxin B1 (AFB1). The study was carried out on 66 male Wistar rats. Following the intraperitoneal (IP) administration of AFB1 at dose of 2 mg/kg, minocycline (45 and 90 mg/kg, IP) and dexamethasone (5 and 20 mg/kg, IP) were administered alone and combined with NAC (200 mg/kg, IP) and vitamin E (600 mg/kg, IP). CoQ10 and MMP-9 levels were analyzed using the HPLC-UV method and a commercial kit by ELISA, respectively. AFB1 increased MMP-9 level and decreased CoQ10 level compared to the control group. After dexamethasone and minocycline administration, there is no increase in CoQ10 level, which is caused by AFB1. However, dexamethasone and minocycline combined with NAC+vitamin E caused significant increases in CoQ10 levels. Dexamethasone and minocycline alone and combined with NAC+vitamin E decreased MMP-9 levels compared to the single AFB1 treated group. The use of MMPs inhibitors and oxidative stress-reducing agents is anticipated to be beneficial in the poisoning with AFB1