3,109 research outputs found
Discovery of Multiply Imaged Galaxies behind the Cluster and Lensed Quasar SDSS J1004+4112
We have identified three multiply imaged galaxies in Hubble Space Telescope
images of the redshift z=0.68 cluster responsible for the large-separation
quadruply lensed quasar, SDSS J1004+4112. Spectroscopic redshifts have been
secured for two of these systems using the Keck I 10m telescope. The most
distant lensed galaxy, at z=3.332, forms at least four images, and an Einstein
ring encompassing 3.1 times more area than the Einstein ring of the lensed QSO
images at z=1.74, due to the greater source distance. For a second multiply
imaged galaxy, we identify Ly_alpha emission at a redshift of z=2.74. The
cluster mass profile can be constrained from near the center of the brightest
cluster galaxy, where we observe both a radial arc and the fifth image of the
lensed quasar, to the Einstein radius of the highest redshift galaxy, ~110 kpc.
Our preliminary modeling indicates that the mass approximates an elliptical
body, with an average projected logarithmic gradient of ~-0.5. The system is
potentially useful for a direct measurement of world models in a previously
untested redshift range.Comment: 5 pages, 3 figures. Accepted by ApJL. High resolution version of the
paper can be found at: http://wise-obs.tau.ac.il/~kerens/papers.htm
The complexity of pluralistic ignorance in Republican climate change policy support in the United States
Most Americans fail to recognize widespread public support for climate change action. Here we investigate how this phenomenon differs for Republican supporters versus opponents of several climate change policies. Surveying a representative sample of Republican voters (N = 1000), we find that misperception of in-group support for climate action is primarily restricted to Republicans already opposed to action. Specifically, those in the minority (i.e., Republicans opposed to climate action) were more likely to erroneously perceive other Republicans as holding views on climate change policy similar to their own. While Republican supporters recognize that most Republicans support climate change policy, they may be discouraged from expressing their support due to an information environment disproportionately portraying Republicans as opposed to climate change action
Working Together: Building K-12/College Mentor Partnerships to Support Students with Learning Differences
In an interactive discussion with audience members, presenters will share ideas for developing positive mentor-mentee partnerships between K-12 schools and colleges; discuss the impact of two recently established mentor partnerships, as well as perspectives from college student mentors and K-12 teachers of student mentees with learning differences; collaboratively examine data to discuss potential program adaptations; and provide mentoring activities that audience members can utilize
Testing models of inflation with CMB non-gaussianity
Two different predictions for the primordial curvature fluctuation bispectrum
are compared through their effects on the Cosmic Microwave Background
temperature fluctuations. The first has a local form described by a single
parameter f_{NL}. The second is based on a prediction from the warm
inflationary scenario, with a different dependence on wavenumber and a
parameter f_{WI}. New expressions are obtained for the angular bispectra of the
temperature fluctuations and for the estimators used to determine and
f_{WI}. The standard deviation of the estimators in an ideal experiment is
roughly 5 times larger for f_{WI} than for f_{NL}. Using 3 year WMAP data gives
limits -375<f_{WI}<36.8, but there is a possibility of detecting a signal for
f_{WI} from the Planck satellite.Comment: 13 pages, 5 figures in ReVTe
A statistical approach for detecting genomic aberrations in heterogeneous tumor samples from single nucleotide polymorphism genotyping data
We describe a statistical method for the characterization of genomic aberrations in single nucleotide polymorphism microarray data acquired from cancer genomes. Our approach allows us to model the joint effect of polyploidy, normal DNA contamination and intra-tumour heterogeneity within a single unified Bayesian framework. We demonstrate the efficacy of our method on numerous datasets including laboratory generated mixtures of normal-cancer cell lines and real primary tumours
Choosing Your Moment: Interruptions in Multimedia Annotation.
In a cooperative mixed-initiative system, timely and effective dialogue between the system and user is important to ensure that both sides work towards producing the most effective results, and this is affected by how disruptive any interruptions are as the user completes their primary task. A disruptive interaction means the user may become irritated with the system, or might take longer to deal with the interruption and provide information that the system needs to continue. Disruption is influenced both by the nature of the interaction and when it takes place in the context of the userâs progress through their main task. We describe an experiment based on a prototype cooperative video annotation system designed to explore the impact of interruptions, in the form of questions posed by the system that the user must address. Our findings demonstrate a preference towards questions presented in context with the content of the video, rather than at the natural opportunities presented by transitions in the video. This differs from previous research which concentrates on interruptions in the form of notifications
From inquilines to gall inducers:Genomic signature of a life-style transition in synergus gall wasps
Gall wasps (Hymenoptera: Cynipidae) induce complex galls on oaks, roses and other plants, but the mechanism of gall induction is still unknown. Here we take a comparative genomic approach to revealing the genetic basis of gall induction. We focus on Synergus itoensis, a species that induces galls inside oak acorns. Previous studies suggested that this species evolved the ability to initiate gall formation recently, as it is deeply nested within the genus Synergus, whose members are mostly inquilines that develop inside the galls of other species. We compared the genome of S. itoensis to that of three related Synergus inquilines to identify genomic changes associated with the origin of gall induction. We used a novel Bayesian selection analysis, which accounts for branch-specific and gene-specific selection effects, to search for signatures of selection in 7,600 single-copy orthologous genes shared by the four Synergus species. We found that the terminal branch leading to S. itoensis had more genes with a significantly elevated dN/dS ratio (Positive Signature Genes, PSGs) than the other terminal branches in the tree; the S. itoensis branch also had more genes with a significantly decreased dN/dS ratio. Gene set enrichment analysis showed that the PSG set of S. itoensis, unlike those of the inquiline species, is enriched in several biological process Gene Ontology terms, the most prominent of which is âOvarian Follicle Cell Developmentâ. Our results indicate that the origin of gall induction is associated with distinct genomic changes, and provide a good starting point for further characterization of the genes involved
Cost-Effectiveness Model for Neovascular Age-Related Macular Degeneration: Comparing Early and Late Treatment with Pegaptanib Sodium Based on Visual Acuity
AbstractObjectiveTo compare the cost-effectiveness of pegaptanib and usual care within three distinct cohorts of subfoveal neovascular age-related macular degeneration (NV-AMD) patients, that is, those with early, moderate, and late disease, using a comprehensive economic model.MethodsA Markov framework was used to model lifetime movement of a subfoveal NV-AMD cohort through health states based on visual acuity. The model takes a US payer perspective of patients over the age of 65 years. Clinical efficacy was based on published results for the 0.3 mg pegaptanib and usual care groups. Expert interviews were conducted to determine adverse event treatment patterns and vision rehabilitation resource use. Incidence and costs of comorbidities such as depression and fractures associated with the effects of declining visual acuity were based on our previously published analysis of Medicare data. Transition probabilities were derived from published clinical trial data for each 3-month cycle. Utilities were derived from published sources. Three runs of the model were conducted with cohorts of newly diagnosed patients. Patients were classified as having early, moderate, or late NV-AMD defined as visual acuity in the better-seeing eye of 20/40 to more than 20/80, 20/80 to more than 20/200, and 20/200 to more than 20/400, respectively. Costs and outcomes were discounted 3.0% per annum.ResultsIncremental costs per vision-year gained and per quality-adjusted life-year (QALY) gained for early NV-AMD patients were approximately one-third those of patients with late disease (57,230 and 132,381, respectively). On average, patients treated early with either pegaptanib or usual care incurred lower lifetime total direct costs than those treated later. Sensitivity analysis showed that base-case incremental costs per QALY gained for pegaptanib versus usual care were relatively robust.ConclusionsFor patients with subfoveal NV-AMD, treatment with pegaptanib should be started as early as possible to maximize the clinical and economic benefits
Photofragment Translational Spectroscopy Studies of H Atom Loss Following Ultraviolet Photoexcitation of Methimazole in the Gas Phase
The
ultraviolet (UV) photodissociation of gas-phase methimazole
has been investigated by H Rydberg atom photofragment translational
spectroscopy methods at many wavelengths in the range of 222.5â275
nm and by complementary electronic structure calculations. Methimazole
is shown to exist predominantly as the thione tautomer, 1-methyl-2Â(3H)-imidazolinethione, rather than the commonly given thiol
form, 2-mercapto-1-methylimidazole. The UV absorption spectrum of
methimazole is dominated by the S4 â S0 transition of the thione tautomer, which involves electron promotion
from an aâČ (py) orbital localized on the sulfur atom to a Ï* orbital localized
around the NâH bond. Two H atom formation pathways are identified
following UV photoexcitation. One, involving prompt, excited-state
NâH bond fission, yields vibrationally cold but rotationally
excited methimazolyl (Myl) radicals in their first excited (AÌ)
electronic state. The second yields H atoms with an isotropic recoil
velocity distribution peaking at low kinetic energies but extending
to the energetic limit allowed by energy conservation given a ground-state
dissociation energy D0(MylâH) âŒ24âŻ000
cmâ1. These latter H atoms are attributed to the
unimolecular decay of highly vibrationally excited S0 parent
molecules. The companion electronic structure calculations provide
rationales for both fragmentation pathways and the accompanying product
energy disposals and highlight similarities and differences between
the UV photochemistry of methimazole and that of other azoles (e.g.,
imidazole) and with molecules like thiourea and thiouracil that contain
similar NâCî»S motifs
Winter Wheat Grain Yield Response to Fungicide Application is Influenced by Cultivar and Rainfall
Winter wheat is susceptible to several fungal pathogens throughout the growing season and foliar fungicide application is one of the strategies used in the management of fungal diseases in winter wheat. However, for fungicides to be profitable, weather conditions conducive to fungal disease development should be present. To determine if winter wheat yield response to fungicide application at the flowering growth stage (Feekes 10.5.1) was related to the growing season precipitation, grain yield from fungicide treated plots was compared to non-treated plots for 19 to 30 hard red winter wheat cultivars planted at 8 site years from 2011 through 2015. At all locations, Prothioconazole + Tebuconazole or Tebuconazole alone was applied at flowering timing for the fungicide treated plots. Grain yield response (difference between treated and non-treated) ranged from 66-696 kg/ha across years and locations. Grain yield response had a positive and significant linear relationship with cumulative rainfall in May through June for the mid and top grain yield ranked cultivars (R2=54%, 78%, respectively) indicating that a higher amount of accumulated rainfall in this period increased chances of getting a higher yield response from fungicide application. Cultivars treated with a fungicide had slightly higher protein content (up to 0.5%) compared to non-treated. These results indicate that application of fungicides when there is sufficient moisture in May and June may increase chances of profitability from fungicide application
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