12 research outputs found
Sub-arcsecond radio and optical observations of the likely counterpart to the gamma-ray source 2FGL J2056.7+4939
We have searched and reviewed all multi- wavelength data available for the
region towards the gamma-ray source 2FGL J2056.7+4939 in order to con- strain
its possible counterpart at lower energies. As a result, only a point-like
optical/infrared source with flat-spectrum radio emission is found to be
consistent with all X-ray and gamma-ray error circles. Its struc- ture is
marginally resolved at radio wavelengths at the sub-arcsecond level. An
extragalactic scenario appears to be the most likely interpretation for this
object.Comment: 5 pages, 3 figures, 1 tabl
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Plasma Levels of Parent Compound and Metabolites after Doses of Either d-Fenfluramine or d-3,4-Methylenedioxymethamphetamine (MDMA) that Produce Long-Term Serotonergic Alterations
Plasma levels of parent compounds and metabolites were determined in adult rhesus monkeys after doses of either 5
mg/kg
d-fenfluramine (FEN) or 10
mg/kg
d-3, 4-methylenedioxymethamphetamine (MDMA) i.m. twice daily for four consecutive days. These treatment regimens have been previously shown to produce long-term serotonin (5-HT) depletions. Peak plasma levels of 2.0±0.4
ÎŒM FEN were reached within 40
min after the first dose of FEN, and then declined rapidly, while peak plasma levels (0.4±0.1
ÎŒM) of the metabolite norfenfluramine (NFEN) were not reached until 6
h after dosing. After the seventh (next to last) dose of FEN, peak plasma levels of FEN were 35% greater than after the first dose while peak NFEN-levels were 500% greater. The
t
1/2 for FEN was 2.6±0.3
h after the first dose and 3.2±0.2
h after the seventh. The estimated
t
1/2 for NFEN was more than 37.6±20.5
h. Peak plasma levels of 9.5±2.5
ÎŒM MDMA were reached within 20
min after the first dose of MDMA, and then declined rapidly, while peak plasma levels (0.9±0.2
ÎŒM) of the metabolite 3,4-methylenedioxyamphetamine (MDA) were not reached until 3â6
h after dosing. After the seventh (next to last) dose of MDMA, peak plasma levels of MDMA were 30% greater than the first dose while peak MDA levels were elevated over 200%. The
t
1/2 for MDMA was 2.8±0.4
h after the first and 3.9±1.1
h after the seventh dose. The estimated
t
1/2 for MDA was about 8.3±1.0
h. Variability in plasma levels of MDMA and MDA between subjects was much greater than that for FEN and NFEN. This variability in MDMA and MDA exposure levels may have lead to variability in the subsequent disruption of some behaviors seen in these same subjects. There were 80% reductions in the plasma membrane-associated 5-HT transporters 6 months after either the FEN or MDMA dosing regimen indicating that both treatments produced long-term serotonergic effects
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OSIRIS-APEX: An OSIRIS-REx Extended Mission to Asteroid Apophis
The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft mission characterized and collected a sample from asteroid (101955) Bennu. After the OSIRIS-REx Sample Return Capsule released to Earthâs surface in 2023 September, the spacecraft diverted into a new orbit that encounters asteroid (99942) Apophis in 2029, enabling a second mission with the same unique capabilities: OSIRIS-Apophis Explorer (APEX). On 2029 April 13, the 340 m diameter Apophis will draw within âŒ32,000 km of Earthâs surface, less than 1/10 the lunar distance. Apophis will be the largest object to approach Earth this closely in recorded history. This rare planetary encounter will alter Apophisâs orbit, will subject it to tidal forces that change its spin state, and may seismically disturb its surface. APEX will distantly observe Apophis during the Earth encounter and capture its evolution in real time, revealing the consequences of an asteroid undergoing tidal disturbance by a major planet. Beginning in 2029 July, the spacecraftâs instrument suite will begin providing high-resolution data of this âstonyâ asteroidâadvancing knowledge of these objects and their connection to meteorites. Near the missionâs end, APEX will use its thrusters to excavate regolith, a technique demonstrated at Bennu. Observations before, during, and after excavation will provide insight into the subsurface and material properties of stony asteroids. Furthermore, Apophisâs material and structure have critical implications for planetary defense. © 2023. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]