28,407 research outputs found
The Absolute Magnitude of the Sun in Several Filters
This paper presents a table with estimates of the absolute magnitude of the
Sun and the conversions from to the AB and ST systems for several
wide-band filters used in ground and space-based observatories. These estimates
use the dustless spectral energy distribution (SED) of Vega, calibrated
absolutely using the SED of Sirius, to set the zero-points and a
composite spectrum of the Sun that coadds space-based observations from the
ultra-violet to the near infrared with models of the Solar atmosphere. The
uncertainty of the absolute magnitudes is estimated comparing the synthetic
colors with photometric measurements of solar analogs and is found to be
0.02 magnitudes. Combined with the uncertainty of 2% in the calibration
of the Vega SED, the errors of these absolute magnitudes are 3--4%.
Using these SEDs, for the three of the most utilized filters in extragalactic
work the estimated absolute magnitudes of the Sun are = 5.44, =
4.81 and = 3.27 mag in the system and = 5.31, =
4.80 and = 5.08 mag in AB.Comment: 17 pages, 2 figures, accepted by ApJS. Composite solar spectrum
available for download at http://mips.as.arizona.edu/~cnaw/sun.htm
Establishment of prophylactic enoxaparin dosing recommendations to achieve targeted anti-factor Xa concentrations in children with CHD
Background
Enoxaparin may be used to prevent central venous catheter-related thrombosis in patients with CHD. We aimed to determine whether current enoxaparin dosing regimens effectively achieve anti-factor Xa concentrations within prophylactic goal ranges in this patient population.
Methods
We implemented a formal protocol aimed at reducing central venous catheter-related thrombosis in children with CHD in January, 2016. Standard empiric prophylactic enoxaparin dosing regimens were used – for example, 0.75 mg/kg/dose every 12 hours for patients <2 months of age and 0.5 mg/kg/dose every 12 hours for patients ⩾2 months of age – with anti-factor Xa goal range of 0.25–0.49 IU/ml. Patients <2 years of age who received enoxaparin and had at least one valid steady-state anti-factor Xa measurement between 25 January, 2016 and 31 August, 2016 were retrospectively reviewed.
Results
During the study period, 47 patients had 186 anti-factor Xa concentrations measured, of which 20 (11%) were above and 112 (60%) were below the prophylactic goal range. Anti-factor Xa concentrations within the goal range were ultimately achieved in 31 patients. Median dose required to achieve anti-factor Xa concentrations within the prophylactic range was 0.89 mg/kg/dose (25, 75%: 0.75, 1.11) for patients <2 months (n=23 patients) and 0.79 mg/kg/dose (25, 75%: 0.62, 1.11) for patients ⩾2 months (n=8 patients).
Conclusions
Enoxaparin doses required to achieve prophylactic anti-factor Xa concentrations in young children with CHD were consistently higher than the currently recommended prophylactic dosing regimens. Further study is needed to determine whether dose titration to achieve prophylactic anti-factor Xa concentrations is effective in preventing central venous catheter-related thrombosis
Building an Optimal Census of the Solar Neighborhood with Pan-STARRS Data
We estimate the fidelity of solar neighborhood (D < 100 pc) catalogs soon to
be derived from Pan-STARRS astrometric data. We explore two quantities used to
measure catalog quality: completeness, the fraction of desired sources included
in a catalog; and reliability, the fraction of entries corresponding to desired
sources. We show that the main challenge in identifying nearby objects with
Pan-STARRS will be reliably distinguishing these objects from distant stars,
which are vastly more numerous. We explore how joint cuts on proper motion and
parallax will impact catalog reliability and completeness. Using synthesized
astrometry catalogs, we derive optimum parallax and proper motion cuts to build
a census of the solar neighborhood with the Pan-STARRS 3 Pi Survey. Depending
on the Galactic latitude, a parallax cut pi / sigma pi > 5 combined with a
proper motion cut ranging from mu / sigma mu > 1-8 achieves 99% reliability and
60% completeness.Comment: 7 Pages, 4 Figures, 3 Tables. PASP in pres
SUDS treatment train assessment tool
This paper outlines a rationale and scoring system for the stormwater treatment train assessment tool (STTAT) which is a proposed regulatory tool for Sustainable Urban Drainage Systems (SUDS). STTAT provides guidance and regulatory consistency for developers about the requirements of planners and the Scottish Environment Protection Agency (SEPA). The tool balances the risks of pollution to the receiving water-body with the treatment provided in a treatment train. It encourages developers to take SUDS into account early, avoiding any misunderstanding of SUDS requirements at the planning stage of a development. A pessimistic view on pollution risks has been adopted since there may be a change of land use on the development in the future. A realistic view has also been taken of maintenance issues and the ‘survivability’ of a SUDS component. The rationale for STTAT as a response to the requirements of the Water Framework Directive is explored and the individual scores are given in tabular format for receiving water and catchment risks. Treatment scores are proposed for single SUDS components as well as multiple components within treatment trains. STTAT has been tested on a range of sites, predominantly in Scotland where both development and receiving water information was known. The operational tool in use by SEPA is presented
Sustainable Urban Drainage Systems (SUDS) treatment train assessment tool
This paper outlines a rationale and scoring system for the stormwater treatment train assessment tool (STTAT) which is a proposed regulatory tool for Sustainable Urban Drainage Systems (SUDS). STTAT provides guidance and regulatory consistency for developers about the requirements of planners and the Scottish Environment Protection Agency (SEPA). The tool balances the risks of pollution to the receiving water body with the treatment provided in a treatment train. It encourages developers to take SUDS into account early, avoiding any misunderstanding of SUDS requirements at the planning stage of a development. A pessimistic view on pollution risks has been adopted since there may be a change of land use on the development in the future. A realistic view has also been taken of maintenance issues and the ‘survivability’ of a SUDS component. The development of STTAT as a response to the requirements of the Water Framework Directive is explored, the individual scores being given in tabular format for receiving water and catchment risks. Treatment scores are proposed for single SUDS components as well as multiple components within treatment trains. STTAT has been tested on a range of sites, predominantly in Scotland where both development and receiving water information was known. The operational tool in use by SEPA is presented
The Yoneda algebra of a graded Ore extension
Let A be a connected-graded algebra with trivial module k, and let B be a
graded Ore extension of A. We relate the structure of the Yoneda algebra E(A)
:= Ext_A(k,k) to E(B). Cassidy and Shelton have shown that when A satisfies
their K_2 property, B will also be K_2. We prove the converse of this result.Comment: 9 page
Study of multiple reserve electrochemical power sources Final report
High energy density electrolytic cell systems for multiple reserve electrochemical spacecraft power supplie
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