170 research outputs found
The Baryon Oscillation Spectroscopic Survey of SDSS-III
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the
scale of baryon acoustic oscillations (BAO) in the clustering of matter over a
larger volume than the combined efforts of all previous spectroscopic surveys
of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as
i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7.
Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000
quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5.
Early results from BOSS include the first detection of the large-scale
three-dimensional clustering of the Lyman alpha forest and a strong detection
from the Data Release 9 data set of the BAO in the clustering of massive
galaxies at an effective redshift z = 0.57. We project that BOSS will yield
measurements of the angular diameter distance D_A to an accuracy of 1.0% at
redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the
same redshifts. Forecasts for Lyman alpha forest constraints predict a
measurement of an overall dilation factor that scales the highly degenerate
D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey
is complete. Here, we provide an overview of the selection of spectroscopic
targets, planning of observations, and analysis of data and data quality of
BOSS.Comment: 49 pages, 16 figures, accepted by A
The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic
data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data
release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median
z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar
spectra, along with the data presented in previous data releases. These spectra
were obtained with the new BOSS spectrograph and were taken between 2009
December and 2011 July. In addition, the stellar parameters pipeline, which
determines radial velocities, surface temperatures, surface gravities, and
metallicities of stars, has been updated and refined with improvements in
temperature estimates for stars with T_eff<5000 K and in metallicity estimates
for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars
presented in DR8, including stars from SDSS-I and II, as well as those observed
as part of the SDSS-III Sloan Extension for Galactic Understanding and
Exploration-2 (SEGUE-2).
The astrometry error introduced in the DR8 imaging catalogs has been
corrected in the DR9 data products. The next data release for SDSS-III will be
in Summer 2013, which will present the first data from the Apache Point
Observatory Galactic Evolution Experiment (APOGEE) along with another year of
data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at
http://www.sdss3.org/dr
Zanamivir Conjugated to Poly-L-Glutamine is Much More Active Against Influenza Viruses in Mice and Ferrets Than the Drug Itself
Purpose:
Previously, polymer-attached zanamivir had been found to inhibit influenza A viruses in vitro far better than did small-molecule zanamivir (1) itself. The aim of this study was to identify in vitro—using the plaque reduction assay—a highly potent 1-polymer conjugate, and subsequently test its antiviral efficacy in vivo.
Methods:
By examining the structure-activity relationship of 1-polymer conjugates in the plaque assay, we have determined that the most potent inhibitor against several representative influenza virus strains has a neutral high-molecular-weight backbone and a short alkyl linker. We have examined this optimal polymeric inhibitor for efficacy and immunogenicity in the mouse and ferret models of infection.
Results:
1 attached to poly-L-glutamine is an effective therapeutic for established influenza infection in ferrets, reducing viral titers up to 30-fold for 6 days. There is also up to a 190-fold reduction in viral load when the drug is used as a combined prophylactic/therapeutic in mice. Additionally, we see no evidence that the drug conjugate stimulates an immune response in mice upon repeat administration.
Conclusions:
1 attached to a neutral high-molecular-weight backbone through a short alkyl linker drastically reduced both in vitro and in vivo titers compared to those observed with 1 itself. Thus, further development of this polymeric zanamivir for the mitigation of influenza infection seems warranted.National Institutes of Health (U.S.) (Grant U01-AI074443
The Baryon Oscillation Spectroscopic Survey of SDSS-III
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg(2) to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Ly alpha forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Ly alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance d(A) to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Ly alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D-A(z) and H-1(z) parameters to an accuracy of 1.9% at z similar to 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Neurosymptomatic carvenous sinus meningioma: a 15-years experience with fractionated stereotactic radiotherapy and radiosurgery
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Spectral Classification and Redshift Measurement for the SDSS-III Baryon Oscillation Spectroscopic Survey
(abridged) We describe the automated spectral classification, redshift
determination, and parameter measurement pipeline in use for the Baryon
Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III
(SDSS-III) as of Data Release 9, encompassing 831,000 moderate-resolution
optical spectra. We give a review of the algorithms employed, and describe the
changes to the pipeline that have been implemented for BOSS relative to
previous SDSS-I/II versions, including new sets of stellar, galaxy, and quasar
redshift templates. For the color-selected CMASS sample of massive galaxies at
redshift 0.4 <~ z <~ 0.8 targeted by BOSS for the purposes of large-scale
cosmological measurements, the pipeline achieves an automated classification
success rate of 98.7% and confirms 95.4% of unique CMASS targets as galaxies
(with the balance being mostly M stars). Based on visual inspections of a
subset of BOSS galaxies, we find that ~0.2% of confidently reported CMASS
sample classifications and redshifts are incorrect, and ~0.4% of all CMASS
spectra are objects unclassified by the current algorithm which are potentially
recoverable. The BOSS pipeline confirms that ~51.5% of the quasar targets have
quasar spectra, with the balance mainly consisting of stars. Statistical (as
opposed to systematic) redshift errors propagated from photon noise are
typically a few tens of km/s for both galaxies and quasars, with a significant
tail to a few hundreds of km/s for quasars. We test the accuracy of these
statistical redshift error estimates using repeat observations, finding them
underestimated by a factor of 1.19 to 1.34 for galaxies, and by a factor of 2
for quasars. We assess the impact of sky-subtraction quality, S/N, and other
factors on galaxy redshift success. Finally, we document known issues, and
describe directions of ongoing development.Comment: 20 pages, multiple figures. Minor changes relative to version 1.
Accepted for publication in The Astronomical Journa
Comparison of the Safety and Pharmacokinetics of ST-246® after IV Infusion or Oral Administration in Mice, Rabbits and Monkeys
ST-246® is an antiviral, orally bioavailable small molecule in clinical development for treatment of orthopoxvirus infections. An intravenous (IV) formulation may be required for some hospitalized patients who are unable to take oral medication. An IV formulation has been evaluated in three species previously used in evaluation of both efficacy and toxicology of the oral formulation. plasma concentrations. These effects were eliminated using slower IV infusions. associated toxicity. Shorter infusions at higher doses in NHP resulted in decreased clearance, suggesting saturated distribution or elimination. Elimination half-lives in all species were similar between oral and IV administration. The administration of ST-246 was well tolerated as a slow IV infusion
Visualization of Murine Intranasal Dosing Efficiency Using Luminescent Francisella tularensis: Effect of Instillation Volume and Form of Anesthesia
Intranasal instillation is a widely used procedure for pneumonic delivery of drugs, vaccine candidates, or infectious agents into the respiratory tract of research mice. However, there is a paucity of published literature describing the efficiency of this delivery technique. In this report we have used the murine model of tularemia, with Francisella tularensis live vaccine strain (FTLVS) infection, to evaluate the efficiency of pneumonic delivery via intranasal dosing performed either with differing instillation volumes or different types of anesthesia. FTLVS was rendered luminescent via transformation with a reporter plasmid that constitutively expressed the Photorhabdus luminescens lux operon from a Francisella promoter. We then used an IVIS Spectrum whole animal imaging system to visualize FT dissemination at various time points following intranasal instillation. We found that instillation of FT in a dose volume of 10 µl routinely resulted in infection of the upper airways but failed to initiate infection of the pulmonary compartment. Efficient delivery of FT into the lungs via intranasal instillation required a dose volume of 50 µl or more. These studies also demonstrated that intranasal instillation was significantly more efficient for pneumonic delivery of FTLVS in mice that had been anesthetized with inhaled (isoflurane) vs. parenteral (ketamine/xylazine) anesthesia. The collective results underscore the need for researchers to consider both the dose volume and the anesthesia type when either performing pneumonic delivery via intranasal instillation, or when comparing studies that employed this technique
Climate drives the geography of marine consumption by changing predator communities
Este artículo contiene 7 páginas, 3 figuras, 1 tabla.The global distribution of primary production and consumption by
humans (fisheries) is well-documented, but we have no map linking
the central ecological process of consumption within food
webs to temperature and other ecological drivers. Using standardized
assays that span 105° of latitude on four continents, we show
that rates of bait consumption by generalist predators in shallow
marine ecosystems are tightly linked to both temperature and the
composition of consumer assemblages. Unexpectedly, rates of
consumption peaked at midlatitudes (25 to 35°) in both Northern
and Southern Hemispheres across both seagrass and unvegetated
sediment habitats. This pattern contrasts with terrestrial systems,
where biotic interactions reportedly weaken away from the equator,
but it parallels an emerging pattern of a subtropical peak in
marine biodiversity. The higher consumption at midlatitudes was
closely related to the type of consumers present, which explained
rates of consumption better than consumer density, biomass, species
diversity, or habitat. Indeed, the apparent effect of temperature
on consumption was mostly driven by temperature-associated turnover
in consumer community composition. Our findings reinforce
the key influence of climate warming on altered species composition
and highlight its implications for the functioning of Earth’s
ecosystems.We acknowledge funding from the Smithsonian
Institution and the Tula Foundation.Peer reviewe
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