649 research outputs found
Sex-specific glioma genome-wide association study identifies new risk locus at 3p21.31 in females, and finds sex-differences in risk at 8q24.21
National Security Entry-Exit Registration System: Effective Tool Against Terrorism or Unnecessary Infringement on Constitutional Rights?
Article published in the Michigan State University School of Law Student Scholarship Collection
Zooming in on accretion - II. Cold Circumgalactic Gas Simulated with a super-Lagrangian Refinement Scheme
In this study we explore the complex multi-phase gas of the circumgalactic
medium (CGM) surrounding galaxies. We propose and implement a novel,
super-Lagrangian 'CGM zoom' scheme in the moving-mesh code AREPO, which focuses
more resolution into the CGM and intentionally lowers resolution in the dense
ISM. We run two cosmological simulations of the same galaxy halo, once with a
simple 'no feedback' model, and separately with a more comprehensive physical
model including galactic-scale outflows as in the Illustris simulation. Our
chosen halo has a total mass of ~10^12 Msun at z ~ 2, and we achieve a median
gas mass (spatial) resolution of ~2,200 solar masses (~95 parsecs) in the CGM,
six-hundred (fourteen) times better than in the Illustris-1 simulation, a
higher spatial resolution than any cosmological simulation at this mass scale
to date. We explore the primary channel(s) of cold-phase CGM gas production in
this regime. We find that winds substantially enhance the amount of cold gas in
the halo, also evidenced in the covering fractions of HI and the equivalent
widths of MgII out to large radii, in better agreement with observations than
the case without galactic winds. Using a tracer particle analysis to follow the
thermodynamic history of gas, we demonstrate how the majority of this cold,
dense gas arises due to rapid cooling of the wind material interacting with the
hot halo, and how large amounts of cold, ~10^4 K gas can be produced and
persist in galactic halos with Tvir ~ 10^6 K. At the resolutions presently
considered, the quantitative properties of the CGM we explore are not
appreciably affected by the refinement scheme.Comment: MNRAS submitted, comments welcome. High-res version at
http://www.mpa-garching.mpg.de/~dnelson/papers/Suresh19_zooming2.pd
Opportunities and challenges for successful use of bevacizumab in pediatrics
Bevacizumab (Avastin) has rapidly gained status as a broadly active agent for malignancies of several different histologies in adults. This activity has spawned a range of uses in pediatrics for both oncologic and non-oncologic indications. Early analyses indicate that pediatric cancers exhibit a spectrum of responses to bevacizumab that suggest its activity may be more limited than in adult oncology. Most exciting, is that for low grade tumors that threaten vision and hearing, there is not only evidence for objective tumor response but for recovery of lost function as well. In addition to oncological indications, there is a range of uses for non-oncologic disease for which bevacizumab has clear activity. Finally, a number of mechanisms have been identified as contributing to bevacizumb resistance in cancer. Elucidating these mechanisms will guide the development of future clinical trials of bevacizumab in pediatric oncology
On the Cosmic Evolution of Fe/Mg in QSO Absorption Line Systems
We investigate the variation of the ratio of the equivalent widths of the
FeII2600 line to the MgII2796,2803 doublet as a
function of redshift in a large sample of absorption lines drawn from the
JHU-SDSS Absorption Line Catalog. We find that despite large scatter, the
observed ratio shows a trend where the equivalent width ratio
decreases monotonically with
increasing redshift over the range . Selecting the
subset of absorbers where the signal-to-noise ratio of the MgII equivalent
width is 3 and modeling the equivalent width ratio
distribution as a gaussian, we find that the mean of the gaussian distribution
varies as . We discuss various possible
reasons for the trend. A monotonic trend in the Fe/Mg abundance ratio is
predicted by a simple model where the abundances of Mg and Fe in the absorbing
clouds are assumed to be the result of supernova ejecta and where the cosmic
evolution in the SNIa and core-collapse supernova rates is related to the
cosmic star-formation rate. If the trend in reflects the
evolution in the abundances, then it is consistent with the predictions of the
simple model.Comment: 10 pages, 4 figures, final version published in MNRA
Geminin deficiency enhances survival in a murine medulloblastoma model by inducing apoptosis of preneoplastic granule neuron precursors
Pattern of relapse and treatment response in WNT-activated medulloblastoma
Over the past decade, wingless-activated (WNT) medulloblastoma has been identified as a candidate for therapy de-escalation based on excellent survival; however, a paucity of relapses has precluded additional analyses of markers of relapse. To address this gap in knowledge, an international cohort of 93 molecularly confirmed WNT MB was assembled, where 5-year progression-free survival is 0.84 (95%, 0.763-0.925) with 15 relapsed individuals identified. Maintenance chemotherapy is identified as a strong predictor of relapse, with individuals receiving high doses of cyclophosphamide or ifosphamide having only one very late molecularly confirmed relapse (p = 0.032). The anatomical location of recurrence is metastatic in 12 of 15 relapses, with 8 of 12 metastatic relapses in the lateral ventricles. Maintenance chemotherapy, specifically cumulative cyclophosphamide doses, is a significant predictor of relapse across WNT MB. Future efforts to de-escalate therapy need to carefully consider not only the radiation dose but also the chemotherapy regimen and the propensity for metastatic relapses
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