227 research outputs found
Genomic and Transcriptomic Alterations Associated with STAT3 Activation in Head and Neck Cancer.
BackgroundHyperactivation of STAT3 via constitutive phosphorylation of tyrosine 705 (Y705) is common in most human cancers, including head and neck squamous carcinoma (HNSCC). STAT3 is rarely mutated in cancer and the (epi)genetic alterations that lead to STAT3 activation are incompletely understood. Here we used an unbiased approach to identify genomic and epigenomic changes associated with pSTAT3(Y705) expression using data generated by The Cancer Genome Atlas (TCGA).Methods and findingsMutation, mRNA expression, promoter methylation, and copy number alteration data were extracted from TCGA and examined in the context of pSTAT3(Y705) protein expression. mRNA expression levels of 1279 genes were found to be associated with pSTAT3(705) expression. Association of pSTAT3(Y705) expression with caspase-8 mRNA expression was validated by immunoblot analysis in HNSCC cells. Mutation, promoter hypermethylation, and copy number alteration of any gene were not significantly associated with increased pSTAT3(Y705) protein expression.ConclusionsThese cumulative results suggest that unbiased approaches may be useful in identifying the molecular underpinnings of oncogenic signaling, including STAT3 activation, in HNSCC. Larger datasets will likely be necessary to elucidate signaling consequences of infrequent alterations
Book Reviews
Reviews of the following books: Chansonetta: The Life and Photographs of Chansonetta Stanley Emmons, 1859-1937 by Marius B. Peladeau; Raymond Then and Now by Ernest H. Knight; The Jesuit Heritage of New England by Vincent A. Lapomarda; The Landing: A Remembrance of Her People and Shipyards by Thomas W. Murphy; A History of the Town of Hancock, 1828-1979 prepared by the Sesquicentennial Committee of the Town of Hancoc
Transforming Marketing Education of the Future: The Role of Intelligent Agent Technologies (IATs) in Enhancing Student Learning
This conceptual paper introduces IATs and discusses how such intelligent and interactive applications can translate into better education environment for marketing curriculum, particularly marketing research. We present a conceptual model based on extant literature. We present some initial test of our conceptual model of IAT usage in marketing education in a marketing research class
Average Emissivity Curve of BATSE Gamma-Ray Bursts with Different Intensities
Six intensity groups with ~150 BATSE gamma-ray bursts each are compared using
average emissivity curves. Time-stretch factors for each of the dimmer groups
are estimated with respect to the brightest group, which serves as the
reference, taking into account the systematics of counts-produced noise effects
and choice statistics. A stretching/intensity anti-correlation is found with
good statistical significance during the average back slopes of bursts. A
stretch factor ~2 is found between the 150 dimmest bursts, with peak flux
4.1 ph
cm^{-2} s^{-1}. On the other hand, while a trend of increasing stretching
factor may exist for rise fronts for burst with decreasing peak flux from >4.1
ph cm^{-2} s^{-1} down to 0.7 ph cm^{-2} s^{-1}, the magnitude of the
stretching factor is less than ~ 1.4 and is therefore inconsistent with
stretching factor of back slope.Comment: 21 pages, 3 figures. Accepted to Ap
Do Gamma-Ray Burst Sources Repeat?
The demonstration of repeated gamma-ray bursts from an individual source
would severely constrain burst source models. Recent reports (Quashnock and
Lamb 1993; Wang and Lingenfelter 1993) of evidence for repetition in the first
BATSE burst catalog have generated renewed interest in this issue. Here, we
analyze the angular distribution of 585 bursts of the second BATSE catalog
(Meegan et al. 1994). We search for evidence of burst recurrence using the
nearest and farthest neighbor statistic and the two-point angular correlation
function. We find the data to be consistent with the hypothesis that burst
sources do not repeat; however, a repeater fraction of up to about 20% of the
observed bursts cannot be excluded.Comment: ApJ Letters, in press, 13 pages, including three embedded figures.
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Direct Spectroscopic Identification of the Origin of 'Green Fuzzy' Emission in Star Forming Regions
"Green fuzzies" or "extended green objects" were discovered in the recent
Spitzer GLIMPSE survey data. These extended sources have enhanced emission in
the 4.5um IRAC channel images (which are generally assigned to be green when
making 3-color RGB images from Spitzer data). Green fuzzies are frequently
found in the vicinities of massive young stellar objects, and it has been
established that they are in some cases associated with outflows. Nevertheless,
the spectral carrier(s) of this enhanced emission is still uncertain. Although
it has been suggested that Br Alpha, H2, [Fe II], and/or broad CO emission may
be contributing to and enhancing the 4.5um flux from these objects, to date
there have been no direct observations of the 4-5um spectra of these objects.
We report here on the first direct spectroscopic identification of the origin
of the green fuzzy emission. We obtained spatially resolved L and M band
spectra for two green fuzzy sources using NIRI on the Gemini North telescope.
In the case of one source, G19.88-0.53, we detect three individual knots of
green fuzzy emission around the source. The knots exhibit a pure molecular
hydrogen line emission spectrum, with the 4.695um v=0-0 S(9) line dominating
the emission in the 4-5um wavelength range, and no detected continuum
component. Our data for G19.88-0.53 prove that green fuzzy emission can be due
primarily to emission lines of molecular hydrogen within the bandpass of the
IRAC 4.5um channel. However, the other target observed, G49.27-0.34, does not
exhibit any line emission and appears to be an embedded massive young stellar
object with a cometary UC HII region. We suggest that the effects of extinction
in the 3-8um wavelength range and an exaggeration in the color stretch of the
4.5um filter in IRAC RGB images could lead to embedded sources such as this one
falsely appearing "green".Comment: 10 pages, 5 figures; Accepted for publication by A
BATSE Observations of Gamma-Ray Burst Spectra. IV. Time-Resolved High-Energy Spectroscopy
We report on the temporal behavior of the high-energy power law continuum
component of gamma-ray burst spectra with data obtained by the Burst and
Transient Source Experiment. We have selected 126 high fluence and high flux
bursts from the beginning of the mission up until the present. Much of the data
were obtained with the Large Area Detectors, which have nearly all-sky
coverage, excellent sensitivity over two decades of energy and moderate energy
resolution, ideal for continuum spectra studies of a large sample of bursts at
high time resolution. At least 8 spectra from each burst were fitted with a
spectral form that consisted of a low-energy power law, a spectral break at
middle energies and a high-energy continuum. In most bursts (122), the
high-energy continuum was consistent with a power law. The evolution of the
fitted high-energy power-law index over the selected spectra for each burst is
inconsistent with a constant for 34% of the total sample. The sample
distribution of the average value for the index from each burst is fairly
narrow, centered on -2.12. A linear trend in time is ruled out for only 20% of
the bursts, with hard-to-soft evolution dominating the sample (100 events). The
distribution for the total change in the power-law index over the duration of a
burst peaks at the value -0.37, and is characterized by a median absolute
deviation of 0.39, arguing that a single physical process is involved. We
present analyses of the correlation of the power-law index with time, burst
intensity and low-energy time evolution. In general, we confirm the general
hard-to-soft spectral evolution observed in the low-energy component of the
continuum, while presenting evidence that this evolution is different in nature
from that of the rest of the continuum.Comment: 30 pages, with 2 tables and 9 figures To appear in The Astrophysical
Journal, April 1, 199
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