613 research outputs found
A regional approach to the geographical study of land drainage enterprises in Champaign County, Illinois
Thesis (M.S.)--University of Illinois at Urbana-Champaign, 1951.Includes bibliographical references
Spin orbit alignment for KELT-7b and HAT-P-56b via Doppler tomography with TRES
We present Doppler tomographic analyses for the spectroscopic transits of
KELT-7b and HAT-P-56b, two hot-Jupiters orbiting rapidly rotating F-dwarf host
stars. These include analyses of archival TRES observations for KELT-7b, and a
new TRES transit observation of HAT-P-56b. We report spin-orbit aligned
geometries for KELT-7b (2.7 +/- 0.6 deg) and HAT-P-56b (8 +/- 2 deg). The host
stars KELT-7 and HAT-P-56 are among some of the most rapidly rotating
planet-hosting stars known. We examine the tidal re-alignment model for the
evolution of the spin-orbit angle in the context of the spin rates of these
stars. We find no evidence that the rotation rates of KELT-7 and HAT-P-56 have
been modified by star-planet tidal interactions, suggesting that the spin-orbit
angle of systems around these hot stars may represent their primordial
configuration. In fact, KELT-7 and HAT-P-56 are two of three systems in
super-synchronous, spin-orbit aligned states, where the rotation periods of the
host stars are faster than the orbital periods of the planets.Comment: 9 pages, accepted for publication in MNRA
Conjunction, O Aranos + Astropoet
1 oval shaped volume, 24 pages.https://digitalcommons.risd.edu/specialcollections_artistsbooks/1136/thumbnail.jp
A Bayesian analysis of the 27 highest energy cosmic rays detected by the Pierre Auger Observatory
It is possible that ultra-high energy cosmic rays (UHECRs) are generated by
active galactic nuclei (AGNs), but there is currently no conclusive evidence
for this hypothesis. Several reports of correlations between the arrival
directions of UHECRs and the positions of nearby AGNs have been made, the
strongest detection coming from a sample of 27 UHECRs detected by the Pierre
Auger Observatory (PAO). However, the PAO results were based on a statistical
methodology that not only ignored some relevant information (most obviously the
UHECR arrival energies but also some of the information in the arrival
directions) but also involved some problematic fine-tuning of the correlation
parameters. Here we present a fully Bayesian analysis of the PAO data
(collected before 2007 September), which makes use of more of the available
information, and find that a fraction F_AGN = 0.15^(+0.10)_(-0.07) of the
UHECRs originate from known AGNs in the Veron-Cetty & Veron (VCV) catalogue.
The hypothesis that all the UHECRs come from VCV AGNs is ruled out, although
there remains a small possibility that the PAO-AGN correlation is coincidental
(F_AGN = 0.15 is 200 times as probable as F_AGN = 0.00).Comment: MNRAS, accepted; 8 pages, 7 figure
Interaction of Disulfiram with Antiretroviral Medications: Efavirenz Increases While Atazanavir Decreases Disulfiram Effect on Enzymes of Alcohol Metabolism
Background and Objectives
Alcohol abuse complicates treatment of HIV disease and is linked to poor outcomes. Alcohol pharmacotherapies, including disulfiram (DIS), are infrequently utilized in co-occurring HIV and alcohol use disorders possibly related to concerns about drug interactions between antiretroviral (ARV) medications and DIS.
Method
This pharmacokinetics study (n = 40) examined the effect of DIS on efavirenz (EFV), ritonavir (RTV), or atazanavir (ATV) and the effect of these ARV medications on DIS metabolism and aldehyde dehydrogenase (ALDH) activity which mediates the DIS-alcohol reaction.
Results
EFV administration was associated with decreased S-Methyl-N-N-diethylthiocarbamate (DIS carbamate), a metabolite of DIS (p = .001) and a precursor to the metabolite responsible for ALDH inhibition, S-methyl-N,N-diethylthiolcarbamate sulfoxide (DETC–MeSO). EFV was associated with increased DIS inhibition of ALDH activity relative to DIS alone administration possibly as a result of EFV-associated induction of CYP 3A4 which metabolizes the carbamate to DETC–MeSO (which inhibits ALDH). Conversely, ATV co-administration reduced the effect of DIS on ALDH activity possibly as a result of ATV inhibition of CYP 3A4. DIS administration had no significant effect on any ARV studied.
Discussion/Conclusions
ATV may render DIS ineffective in treatment of alcoholism.
Future Directions
DIS is infrequently utilized in HIV-infected individuals due to concerns about adverse interactions and side effects. Findings from this study indicate that, with ongoing clinical monitoring, DIS should be reconsidered given its potential efficacy for alcohol and potentially, cocaine use disorders, that may occur in this population. (Am J Addict 2014;23:137–144
KELT-10b: The First Transiting Exoplanet from the KELT-South Survey -- A Hot Sub-Jupiter Transiting a V = 10.7 Early G-Star
We report the discovery of KELT-10b, the first transiting exoplanet
discovered using the KELT-South telescope. KELT-10b is a highly inflated
sub-Jupiter mass planet transiting a relatively bright star (TYC
8378-64-1), with T = K, =
and [Fe/H] = , an inferred mass
M = M and radius R =
R. The planet has a radius R =
R and mass M =
M. The planet has an eccentricity consistent with zero and a semi-major
axis = AU. The best fitting linear
ephemeris is = 2457066.720450.00027 BJD and P =
4.16627390.0000063 days. This planet joins a group of highly inflated
transiting exoplanets with a radius much larger and a mass much less than those
of Jupiter. The planet, which boasts deep transits of 1.4%, has a relatively
high equilibrium temperature of T = K, assuming zero
albedo and perfect heat redistribution. KELT-10b receives an estimated
insolation of 10 erg s cm,
which places it far above the insolation threshold above which hot Jupiters
exhibit increasing amounts of radius inflation. Evolutionary analysis of the
host star suggests that KELT-10b is unlikely to survive beyond the current
subgiant phase, due to a concomitant in-spiral of the planet over the next
1 Gyr. The planet transits a relatively bright star and exhibits the
third largest transit depth of all transiting exoplanets with V 11 in the
southern hemisphere, making it a promising candidate for future atmospheric
characterization studies.Comment: 20 pages, 13 figures, 7 tables, accepted for publication in MNRA
Sperm design and variation in the New World blackbirds (Icteridae)
Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other taxa, these relationships are negative, and the causes of these different patterns across taxa are poorly understood. In a comparative study using New World blackbirds (Icteridae), we tested whether sperm design was influenced by the level of PCSS and found significant positive associations with the level of PCSS for all sperm components but head length. Additionally, whereas the absolute length of sperm components increased, their variation declined with the intensity of PCSS, indicating stabilizing selection around an optimal sperm design. Given the diversity of, and strong selection on, sperm design, it seems likely that sperm phenotype may influence sperm velocity within species. However, in contrast to other recent studies of passerine birds, but consistent with several other studies, we found no significant link between sperm design and velocity, using four different species that vary both in sperm design and PCSS. Potential reasons for this discrepancy between studies are discussed
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