2,639 research outputs found
Pharmacokinetics and protein binding of morphine in horses
Morphine could be detected in horses dosed with 0.1 mg of drug/kg of body weight for up to 48 hours in blood and 144 hours in urine. This dose of morphine elicited no observable effects and is a suggested analgesic dose. Computer analysis revealed that a 3-compartment open system was the best fitting model with a serum half life of 87.9 minutes and a urine half life of 101.1 minutes. Binding to equine serum proteins was linear over a drug concentration range of 3.88 x 10-5M to 3.50 x 10-aM and averaged 31.6%. In RBC-partitioning experiments, 78.1 % of the drug was found in the plasma fraction. The data indicated that a horse should not be given morphine closer than 1 week before a race
DETECTION OF MORPHINE AND ITS ANALOGUES USING ENZYMATIC HYDROLYSIS
The invention relates to a method for hydrolyzing drug glucuronic acid conjugates present in mammalian body fluids, the conjugates being derived from a narcotic analgesic, antagonist, or agonist-antagonist whose metabolism includes conjugation with glucuronic acid. The method comprises incubating the body fluid sample at from about 60 to about 70° C., for at least about 1 hour, with 3-glucuronidase derived from Patella vulgata, and substantially increases the sensitivity of chromatographic techniques for the detection of morphine and its analogues
Quantitative Spectroscopy of Supernovae for Dark Energy Studies
Detailed quantitative spectroscopy of Type Ia supernovae (SNe~Ia) provides
crucial information needed to minimize systematic effects in both ongoing SNe
Ia observational programs such as the Nearby Supernova Factory, ESSENCE, and
the SuperNova Legacy Survey (SNLS) and in proposed JDEM missions such as SNAP,
JEDI, and DESTINY.
Quantitative spectroscopy is mandatory to quantify and understand the
observational strategy of comparing ``like versus like''. It allows us to
explore evolutionary effects, from variations in progenitor metallicity to
variations in progenitor age, to variations in dust with cosmological epoch. It
also allows us to interpret and quantify the effects of asphericity, as well as
different amounts of mixing in the thermonuclear explosion.Comment: White paper submitted to the Dark Energy Task Force, 13 pages, 5
figure
Precise time delays from strongly gravitationally lensed type Ia supernovae with chromatically microlensed images
Time delays between the multiple images of strongly gravitationally lensed Type Ia supernovae (glSNe Ia) have the potential to deliver precise cosmological constraints, but the effects of microlensing on time delay extraction have not been studied in detail. Here we quantify the effect of microlensing on the glSN Ia yield of the Large Synoptic Survey Telescope (LSST) and the effect of microlensing on the precision and accuracy of time delays that can be extracted from LSST glSNe Ia. Microlensing has a negligible effect on the LSST glSN Ia yield, but it can be increased by a factor of ∼2 over previous predictions to 930 systems using a novel photometric identification technique based on spectral template fitting. Crucially, the microlensing of glSNe Ia is achromatic until three rest-frame weeks after the explosion, making the early-time color curves microlensing-insensitive time delay indicators. By fitting simulated flux and color observations of microlensed glSNe Ia with their underlying, unlensed spectral templates, we forecast the distribution of absolute time delay error due to microlensing for LSST, which is unbiased at the sub-percent level and peaked at 1% for color curve observations in the achromatic phase, while for light-curve observations it is comparable to state-of-the-art mass modeling uncertainties (4%). About 70% of LSST glSN Ia images should be discovered during the achromatic phase, indicating that microlensing time delay uncertainties can be minimized if prompt multicolor follow-up observations are obtained. Accounting for microlensing, the 1-2 day time delay on the recently discovered glSN Ia iPTF16geu can be measured to 40% precision, limiting its cosmological utility
Correcting the z~8 Galaxy Luminosity Function for Gravitational Lensing Magnification Bias
We present a Bayesian framework to account for the magnification bias from
both strong and weak gravitational lensing in estimates of high-redshift galaxy
luminosity functions. We illustrate our method by estimating the UV
luminosity function using a sample of 97 Y-band dropouts (Lyman break galaxies)
found in the Brightest of Reionizing Galaxies (BoRG) survey and from the
literature. We find the luminosity function is well described by a Schechter
function with characteristic magnitude of ,
faint-end slope of , and number density of
. These
parameters are consistent within the uncertainties with those inferred from the
same sample without accounting for the magnification bias, demonstrating that
the effect is small for current surveys at , and cannot account for the
apparent overdensity of bright galaxies compared to a Schechter function found
recently by Bowler et al. (2014a,b) and Finkelstein et al. (2014). We estimate
that the probability of finding a strongly lensed source in our sample
is in the range depending on limiting magnitude. We identify one
strongly-lensed candidate and three cases of intermediate lensing in BoRG
(estimated magnification ) in addition to the previously known
candidate group-scale strong lens. Using a range of theoretical luminosity
functions we conclude that magnification bias will dominate wide field surveys
-- such as those planned for the Euclid and WFIRST missions -- especially at
. Magnification bias will need to be accounted for in order to derive
accurate estimates of high-redshift luminosity functions in these surveys and
to distinguish between galaxy formation models.Comment: Accepted for publication in ApJ. 20 pages, 13 figure
Spectral Models for Early Time SN 2011fe Observations
We use observed UV through near IR spectra to examine whether SN 2011fe can
be understood in the framework of Branch-normal SNe Ia and to examine its
individual peculiarities. As a benchmark, we use a delayed-detonation model
with a progenitor metallicity of Z_solar/20. We study the sensitivity of
features to variations in progenitor metallicity, the outer density profile,
and the distribution of radioactive nickel. The effect of metallicity
variations in the progenitor have a relatively small effect on the synthetic
spectra. We also find that the abundance stratification of SN 2011fe resembles
closely that of a delayed detonation model with a transition density that has
been fit to other Branch-normal Type Ia supernovae. At early times, the model
photosphere is formed in material with velocities that are too high, indicating
that the photosphere recedes too slowly or that SN 2011fe has a lower specific
energy in the outer ~0.1 M_sun than does the model. We discuss several
explanations for the discrepancies. Finally, we examine variations in both the
spectral energy distribution and in the colors due to variations in the
progenitor metallicity, which suggests that colors are only weak indicators for
the progenitor metallicity, in the particular explosion model that we have
studied. We do find that the flux in the U band is significantly higher at
maximum light in the solar metallicity model than in the lower metallicity
model and the lower metallicity model much better matches the observed
spectrum.Comment: 9 pages, 14 figures, MNRAS, in press, fixed typ
The Subluminous and Peculiar Type Ia Supernova PTF09dav
PTF09dav is a peculiar subluminous type Ia supernova (SN) discovered by the
Palomar Transient Factory (PTF). Spectroscopically, it appears superficially
similar to the class of subluminous SN1991bg-like SNe, but it has several
unusual features which make it stand out from this population. Its peak
luminosity is fainter than any previously discovered SN1991bg-like SN Ia (M_B
-15.5), but without the unusually red optical colors expected if the faint
luminosity were due to extinction. The photospheric optical spectra have very
unusual strong lines of Sc II and Mg I, with possible Sr II, together with
stronger than average Ti II and low velocities of ~6000 km/s. The host galaxy
of PTF09dav is ambiguous. The SN lies either on the extreme outskirts (~41kpc)
of a spiral galaxy, or in an very faint (M_R>-12.8) dwarf galaxy, unlike other
1991bg-like SNe which are invariably associated with massive, old stellar
populations. PTF09dav is also an outlier on the light-curve-width--luminosity
and color--luminosity relations derived for other sub-luminous SNe Ia. The
inferred 56Ni mass is small (0.019+/-0.003Msun), as is the estimated ejecta
mass of 0.36Msun. Taken together, these properties make PTF09dav a remarkable
event. We discuss various physical models that could explain PTF09dav. Helium
shell detonation or deflagration on the surface of a CO white-dwarf can explain
some of the features of PTF09dav, including the presence of Sc and the low
photospheric velocities, but the observed Si and Mg are not predicted to be
very abundant in these models. We conclude that no single model is currently
capable of explaining all of the observed signatures of PTF09dav.Comment: Accepted for publication in Ap
Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times
We present optical spectra of the nearby Type Ia supernova SN 2011fe at 100,
205, 311, 349, and 578 days post-maximum light, as well as an ultraviolet
spectrum obtained with Hubble Space Telescope at 360 days post-maximum light.
We compare these observations with synthetic spectra produced with the
radiative transfer code PHOENIX. The day +100 spectrum can be well fit with
models which neglect collisional and radiative data for forbidden lines.
Curiously, including this data and recomputing the fit yields a quite similar
spectrum, but with different combinations of lines forming some of the stronger
features. At day +205 and later epochs, forbidden lines dominate much of the
optical spectrum formation; however, our results indicate that recombination,
not collisional excitation, is the most influential physical process driving
spectrum formation at these late times. Consequently, our synthetic optical and
UV spectra at all epochs presented here are formed almost exclusively through
recombination-driven fluorescence. Furthermore, our models suggest that the
ultraviolet spectrum even as late as day +360 is optically thick and consists
of permitted lines from several iron-peak species. These results indicate that
the transition to the "nebular" phase in Type Ia supernovae is complex and
highly wavelength-dependent.Comment: 22 pages, 21 figuress, 1 table, submitted to MNRA
- …