227 research outputs found

    Traffic Engineers are Land-Use Planners

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    The Impact of Interstate Highways in Rural Areas

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    Genomic and Transcriptomic Alterations Associated with STAT3 Activation in Head and Neck Cancer.

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    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

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    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

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    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

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    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?

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    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. uuencoded Unix-compressed PostScrip

    Direct Spectroscopic Identification of the Origin of 'Green Fuzzy' Emission in Star Forming Regions

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    "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

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    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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