542 research outputs found
Measuring the halo mass of MgII absorbers from their cross-correlation with Luminous Red Galaxies
We study the cross-correlation between 716 MgII quasar absorption systems and
about 100,000 Luminous Red Galaxies (LRGs) selected from the Sloan Digital Sky
Survey Data Release 3 in the redshift range 0.4<z<0.8. The MgII systems were
selected to have 2796 & 2803 rest-frame equivalent widths greater than 1.0 \AA
and identifications confirmed by the FeII 2600 or MgI 2852 lines. Over
co-moving scales 0.2--13/h Mpc, the MgII--LRG cross-correlation has an
amplitude 0.69+/-0.09 times that of the LRG--LRG auto-correlation. Since LRGs
have halo-masses of 10^{13} \msun, this strong cross-correlation implies that
the absorber host-galaxies have halo-masses 1--2 times 10^{12} \msun.Comment: 3 pages, 2 figures, to appear in IAU 199 conf. proc.: "Probing
Galaxies through Quasar Absorption Lines," eds. Williams, Shu, Menard; minor
changes to match the edited versio
The History of Cosmological Star Formation: Three Independent Approaches and a Critical Test Using the Extragalactic Background Light
Taking three independent approaches, we investigate the simultaneous
constraints set on the cosmic star formation history from various observations,
including stellar mass density and extragalactic background light (EBL). We
compare results based on: 1) direct observations of past light-cone, 2) a model
using local fossil evidence constrained by SDSS observations at z~0 (the
`Fossil' model), and 3) theoretical ab initio models from three calculations of
cosmic star formation history: (a) new (1024)^3 Total Variation Diminishing
(TVD) cosmological hydrodynamic simulation, (b) analytic expression of
Hernquist & Springel based on cosmological Smoothed Particle Hydrodynamics
(SPH) simulations, and (c) semi-analytic model of Cole et al. We find good
agreement among the three independent approaches up to the order of
observational errors, except that all the models predict bolometric EBL of
I_tot ~= 37-52 nW m^-2 sr^-1, which is at the lower edge of the the
observational estimate by Hauser & Dwek. We emphasize that the Fossil model
that consists of two components -- spheroids and disks --, when normalized to
the local observations, provides a surprisingly simple but accurate description
of the cosmic star formation history and other observable quantities. Our
analysis suggests that the consensus global parameters at z=0 are: Omega_* =
0.0023+-0.0004, I_EBL = 43+-7 nW m^-2 sr^-1 rho_SFR=(1.06+-0.22)e-2 Msun yr^-1
Mpc^-3, j_bol = (3.1+-0.2)e8 Lsun Mpc^-3.Comment: 40 page, 10 figures. ApJ in press. Matched to the accepted versio
Probabilistic analysis of the upwind scheme for transport
We provide a probabilistic analysis of the upwind scheme for
multi-dimensional transport equations. We associate a Markov chain with the
numerical scheme and then obtain a backward representation formula of
Kolmogorov type for the numerical solution. We then understand that the error
induced by the scheme is governed by the fluctuations of the Markov chain
around the characteristics of the flow. We show, in various situations, that
the fluctuations are of diffusive type. As a by-product, we prove that the
scheme is of order 1/2 for an initial datum in BV and of order 1/2-a, for all
a>0, for a Lipschitz continuous initial datum. Our analysis provides a new
interpretation of the numerical diffusion phenomenon
The Blue Straggler population in the globular cluster M53 (NGC5024): a combined HST, LBT, CFHT study
We used a proper combination of multiband high-resolution and wide field
multi-wavelength observations collected at three different telescopes (HST, LBT
and CFHT) to probe Blue Straggler Star (BSS) populations in the globular
cluster M53. Almost 200 BSS have been identified over the entire cluster
extension. The radial distribution of these stars has been found to be bimodal
(similarly to that of several other clusters) with a prominent dip at ~60'' (~2
r_c) from the cluster center. This value turns out to be a factor of two
smaller than the radius of avoidance (r_avoid, the radius within which all the
stars of ~1.2 M_sun have sunk to the core because of dynamical friction effects
in an Hubble time). While in most of the clusters with a bimodal BSS radial
distribution, r_avoid has been found to be located in the region of the
observed minimum, this is the second case (after NGC6388) where this
discrepancy is noted. This evidence suggests that in a few clusters the
dynamical friction seems to be somehow less efficient than expected.
We have also used this data base to construct the radial star density profile
of the cluster: this is the most extended and accurate radial profile ever
published for this cluster, including detailed star counts in the very inner
region. The star density profile is reproduced by a standard King Model with an
extended core (~25'') and a modest value of the concentration parameter
(c=1.58). A deviation from the model is noted in the most external region of
the cluster (at r>6.5' from the center). This feature needs to be further
investigated in order to address the possible presence of a tidal tail in this
cluster.Comment: 25 pages, 9 figures, accepted for publication on Ap
Phase I study of TP300 in patients with advanced solid tumors with pharmacokinetic, pharmacogenetic and pharmacodynamic analyses
Background: A Phase I dose escalation first in man study assessed maximum tolerated dose (MTD), dose-limiting toxicity (DLT) and recommended Phase II dose of TP300, a water soluble prodrug of the Topo-1 inhibitor TP3076, and active metabolite, TP3011.
<p/>Methods: Eligible patients with refractory advanced solid tumors, adequate performance status, haematologic, renal, and hepatic function. TP300 was given as a 1-hour i.v. infusion 3-weekly and pharmacokinetic (PK) profiles of TP300, TP3076 and TP3011 were analysed. Polymorphisms in CYP2D6, AOX1 and UGT1A1 were studied and DNA strand-breaks measured in peripheral blood mononuclear cells (PBMCs).
<p/>Results: 32 patients received TP300 at 1, 2, 4, 6, 8, 10, 12 mg/m2. MTD was 10 mg/m2; DLTs at 12 (2/4 patients) and 10 mg/m2 (3/12) included thrombocytopenia and febrile neutropenia; diarrhea was uncommon. Six patients (five had received irinotecan), had stable disease for 1.5-5 months. TP3076 showed dose proportionality in AUC and Cmax from 1--10 mg/m2. Genetic polymorphisms had no apparent influence on exposure. DNA strand-breaks were detected after TP300 infusion.
<p/>Conclusions: TP300 had predictable hematologic toxicity, and diarrhea was uncommon. AUC at MTD is substantially greater than for SN38. TP3076 and TP3011 are equi-potent with SN38, suggesting a PK advantage
Big Line Bundles over Arithmetic Varieties
We prove a Hilbert-Samuel type result of arithmetic big line bundles in
Arakelov geometry, which is an analogue of a classical theorem of Siu. An
application of this result gives equidistribution of small points over
algebraic dynamical systems, following the work of Szpiro-Ullmo-Zhang. We also
generalize Chambert-Loir's non-archimedean equidistribution
o.OM: Structured-Functional Communication between Computer Music Systems using OSC and Odot
International audienceO.—odot—is a portable media programming framework based on the OSC data encoding. It embeds a small expression language which allows writing and executing programs in OSC structures. The integration of programming and declarative functional descriptions within data transfer protocols enables structured and expressive communication in media systems: program snippets can be distributed in OSC messages, which evaluate to further OSC messages in the different communicating software. We present experiments using this framework in the OpenMusic computer-aided composition environment , and illustrate via case studies some advantages of such integrated system
The Role of Sub-damped Lyman-alpha Absorbers in the Cosmic Evolution of Metals
Observations of low mean metallicity of damped Lyman-alpha (DLA) quasar
absorbers at all redshifts studied appear to contradict the predictions for the
global mean interstellar metallicity in galaxies from cosmic chemical evolution
models. On the other hand, a number of metal-rich sub-DLA systems have been
identified recently, and the fraction of metal-rich sub-DLAs appears to be
considerably larger than that of metal-rich DLAs, especially at z < 1.5. In
view of this, here we investigate the evolution of metallicity in sub-DLAs. We
find that the mean Zn metallicity of the observed sub-DLAs may be higher than
that of the observed DLAs, especially at low redshifts, reaching a near-solar
level at z <~ 1. This trend does not appear to be an artifact of sample
selection, the use of Zn, the use of N_{HI}-weighting, or observational
sensitivity. While a bias against very low metallicity could be present in the
sub-DLA sample in some situations, this cannot explain the difference between
the DLA and sub-DLA metallicities at low z. The primary reason for the
difference between the DLAs and sub-DLAs appears to be the dearth of metal-rich
DLAs. We estimate the sub-DLA contribution to the total metal budget using
measures of their metallicity and comoving gas density. These calculations
suggest that at z <~ 1, the contribution of sub-DLAs to the total metal budget
may be several times that of DLAs. At higher redshifts also, there are
indications that the sub-DLAs may contribute significantly to the cosmic metal
budget.Comment: 9 pages, 2 figures, Accepted for Publication in the Astrophysical
Journa
A Call to Action for Optimizing the Electronic Health Record in the Parenteral Nutrition Workflow
Parenteral nutrition (PN) is a complex therapeutic modality provided to neonates, children, and adults for various indications. Surveys have shown that current electronic health record (EHR) systems are in need of functionality enhancement for safe and optimal delivery of PN. This is a consensus statement from the American Society for Parenteral and Enteral Nutrition, the Academy of Nutrition and Dietetics, and the American Society of Health‐System Pharmacists outlining some of the key challenges to prescribing, order review/verification, compounding, and administration of PN using EHRs today and is a call to action for clinicians and vendors to optimize their EHRs regarding the PN build and workflow.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146340/1/ncp10095.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146340/2/ncp10095_am.pd
A Call to Action for Optimizing the Electronic Health Record in the Parenteral Nutrition Workflow: Executive Summary
Parenteral nutrition (PN) is a complex therapeutic modality provided to neonates, children, and adults for various indications. Surveys have shown that current electronic health record (EHR) systems are in need of functionality enhancement for safe and optimal delivery of PN. This is a consensus statement from the American Society for Parenteral and Enteral Nutrition, the Academy of Nutrition and Dietetics, and the American Society of Health‐System Pharmacists outlining some of the key challenges to prescribing, order review/verification, compounding, and administration of PN using EHRs today and is a call to action for clinicians and vendors to optimize their EHRs regarding the PN build and workflow.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146349/1/ncp10202.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146349/2/ncp10202_am.pd
- …