235 research outputs found
Colonic ulcerations may predict steroid-refractory course in patients with ipilimumab-mediated enterocolitis
To investigate management of patients who develop ipilimumab-mediated enterocolitis, including association of endoscopic findings with steroid-refractory symptoms and utility of infliximab as second-line therapy
The Role of Dwarf Galaxies in Building Large Stellar Halos
The hierarchical theory of galaxy formation rests on the idea that smaller
galactic structures merge to form the galaxies that we see today. The past
decade has provided remarkable observational support for this scenario, driven
in part by advances in spectroscopic instrumentation. Multi-object spectroscopy
enabled the discovery of kinematically cold substructures around the Milky Way
and M31 that are likely the debris of disrupting satellites. Improvements in
high-resolution spectroscopy have produced key evidence that the abundance
patterns of the Milky Way halo and its dwarf satellites can be explained by
Galactic chemical evolution models based on hierarchical assembly.
These breakthroughs have depended almost entirely on observations of nearby
stars in the Milky Way and luminous red giant stars in M31 and Local Group
dwarf satellites. In the next decade, extremely large telescopes will allow
observations far down the luminosity function in the known dwarf galaxies, and
they will enable observations of individual stars far out in the Galactic halo.
The chemical abundance census now available for the Milky Way will become
possible for our nearest neighbor, M31. Velocity dispersion measurements now
available in M31 will become possible for systems beyond the Local Group such
as Sculptor and M81 Group galaxies. Detailed studies of a greater number of
individual stars in a greater number of spiral galaxies and their satellites
will test hierarchical assembly in new ways because dynamical and chemical
evolution models predict different outcomes for halos of different masses in
different environments.Comment: Astro2010 Decadal Survey White Paper, 8 page
Which comforting messages really work best? A different perspective on Lemieux and Tigheâs âreceiver perspectiveâ
Abstract OnlyThis article responds critically to a recent article by Lemieux and Tighe (Communication Research Reports, 21, 144â153, 2004) in which the authors conclude that recipients of comforting efforts prefer messages that exhibit a moderate rather than high level of person centeredness. It is argued that an erroneous assumption made by Lemieux and Tighe about the status of âreceiver perspectiveâ research on the comforting process led to faulty interpretations of the data and unwarranted conclusions about recipient preferences regarding comforting messages. Alternative interpretations of Lemieux and Tighe's data are presented; these are guided by the extensive previous research that has assessed evaluations and outcomes of comforting messages
New Constraints on Cosmic Reionization from the 2012 Hubble Ultra Deep Field Campaign
Understanding cosmic reionization requires the identification and
characterization of early sources of hydrogen-ionizing photons. The 2012 Hubble
Ultra Deep Field (UDF12) campaign has acquired the deepest infrared images with
the Wide Field Camera 3 aboard Hubble Space Telescope and, for the first time,
systematically explored the galaxy population deep into the era when cosmic
microwave background (CMB) data indicates reionization was underway. The UDF12
campaign thus provides the best constraints to date on the abundance,
luminosity distribution, and spectral properties of early star-forming
galaxies. We synthesize the new UDF12 results with the most recent constraints
from CMB observations to infer redshift-dependent ultraviolet (UV) luminosity
densities, reionization histories, and electron scattering optical depth
evolution consistent with the available data. Under reasonable assumptions
about the escape fraction of hydrogen ionizing photons and the intergalactic
medium clumping factor, we find that to fully reionize the universe by redshift
z~6 the population of star-forming galaxies at redshifts z~7-9 likely must
extend in luminosity below the UDF12 limits to absolute UV magnitudes of
M_UV\sim -13 or fainter. Moreover, low levels of star formation extending to
redshifts z~15-25, as suggested by the normal UV colors of z\simeq7-8 galaxies
and the smooth decline in abundance with redshift observed by UDF12 to
z\simeq10, are additionally likely required to reproduce the optical depth to
electron scattering inferred from CMB observations.Comment: Version accepted by ApJ (originally submitted Jan 5, 2013). The UDF12
website can be found at http://udf12.arizona.ed
Science results from the imaging Fourier transform spectrometer SpIOMM
SpIOMM is an imaging Fourier transform spectrometer designed to obtain the
visible range (350 to 850 nm) spectrum of every light source in a circular
field of view of 12 arcminutes in diameter. It is attached to the 1.6-m
telescope of the Observatoire du Mont Megantic in southern Quebec. We present
here some results of three successful observing runs in 2007, which highlight
SpIOMMs capabilities to map emission line objects over a very wide field of
view and a broad spectral range. In particular, we discuss data cubes from the
planetary nebula M27, the supernova remnants NGC 6992 and M1, the barred spiral
galaxy NGC7479, as well as Stephans quintet, an interacting group of galaxies.Comment: 10 pages, 7 figures, to appear in "Ground-based and Airborne
Instrumentation for Astronomy II", SPIE conference, Marseille, 23-28 June
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Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.
Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29)
The UV Luminosity Function of Star-forming Galaxies via Dropout Selection at Redshifts z ~ 7 and 8 from the 2012 Ultra Deep Field Campaign
We present a catalog of high-redshift star-forming galaxies selected to lie within the redshift range z â 7-8 using the Ultra Deep Field 2012 (UDF12), the deepest near-infrared (near-IR) exposures yet taken with the Hubble Space Telescope (HST). As a result of the increased near-IR exposure time compared to previous HST imaging in this field, we probe ~0.65 (0.25) mag fainter in absolute UV magnitude, at z ~ 7 (8), which increases confidence in a measurement of the faint end slope of the galaxy luminosity function. Through a 0.7 mag deeper limit in the key F105W filter that encompasses or lies just longward of the Lyman break, we also achieve a much-refined color-color selection that balances high redshift completeness and a low expected contamination fraction. We improve the number of dropout-selected UDF sources to 47 at z ~ 7 and 27 at z ~ 8. Incorporating brighter archival and ground-based samples, we measure the z â 7 UV luminosity function to an absolute magnitude limit of M_(UV) = â17 and find a faint end Schechter slope of É =-1.87^(+0.18)_(-0.17). Using a similar color-color selection at z â 8 that takes our newly added imaging in the F140W filter into account, and incorporating archival data from the HIPPIES and BoRG campaigns, we provide a robust estimate of the faint end slope at z â 8, É =-1.94^(+0.21)_(-0.24). We briefly discuss our results in the context of earlier work and that derived using the same UDF12 data but with an independent photometric redshift technique
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Extended haplotype association study in Crohnâs disease identifies a novel, Ashkenazi Jewish-specific missense mutation in the NF-ÎșB pathway gene, HEATR3
The Ashkenazi Jewish population has a several-fold higher prevalence of Crohnâs disease compared to non-Jewish European ancestry populations and has a unique genetic history. Haplotype association is critical to Crohnâs disease etiology in this population, most notably at NOD2, in which three causal, uncommon, and conditionally independent NOD2 variants reside on a shared background haplotype. We present an analysis of extended haplotypes which showed significantly greater association to Crohnâs disease in the Ashkenazi Jewish population compared to a non-Jewish population (145 haplotypes and no haplotypes with P-value < 10â3, respectively). Two haplotype regions, one each on chromosomes 16 and 21, conferred increased disease risk within established Crohnâs disease loci. We performed exome sequencing of 55 Ashkenazi Jewish individuals and follow-up genotyping focused on variants in these two regions. We observed Ashkenazi Jewish-specific nominal association at R755C in TRPM2 on chromosome 21. Within the chromosome 16 region, R642S of HEATR3 and rs9922362 of BRD7 showed genome-wide significance. Expression studies of HEATR3 demonstrated a positive role in NOD2-mediated NF-ÎșB signaling. The BRD7 signal showed conditional dependence with only the downstream rare Crohnâs disease-causal variants in NOD2, but not with the background haplotype; this elaborates NOD2 as a key illustration of synthetic association
The Web Epoch of Reionization Lyman- Survey (WERLS) I. MOSFIRE Spectroscopy of Lyman- Emitters
We present the first results from the Web Epoch of Reionization
Lyman- Survey (WERLS), a spectroscopic survey of Lyman-
emission using Keck I/MOSFIRE and LRIS. WERLS targets bright () galaxy
candidates with photometric redshifts of selected
from pre-JWST imaging embedded in the Epoch of Reionization (EoR) within three
JWST deep fields: CEERS, PRIMER, and COSMOS-Web. Here, we report 11
Lyman- emitters (LAEs; 3 secure and 8 tentative candidates) detected in
the first five nights of WERLS MOSFIRE data. We estimate our observed LAE yield
is %, broadly consistent with expectations assuming some loss from
redshift uncertainty, contamination from sky OH lines, and that the Universe is
approximately half-ionized at this epoch, whereby observable Lyman-
emission is unlikely for galaxies embedded in a neutral intergalactic medium.
Our targets are selected to be UV-bright, and span a range of absolute UV
magnitudes with . With two LAEs detected at
, we also consider the possibility of an ionized bubble at this
redshift. Future synergistic Keck+JWST efforts will provide a powerful tool for
pinpointing beacons of reionization and mapping the large scale distribution of
mass relative to the ionization state of the Universe.Comment: 27 pages, 8 figures; ApJ submitte
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