5,400 research outputs found

    Diffraction-limited Subaru imaging of M82: sharp mid-infrared view of the starburst core

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    We present new imaging at 12.81 and 11.7 microns of the central ~40"x30" (~0.7x0.5 kpc) of the starburst galaxy M82. The observations were carried out with the COMICS mid-infrared (mid-IR) imager on the 8.2m Subaru telescope, and are diffraction-limited at an angular resolution of <0".4. The images show extensive diffuse structures, including a 7"-long linear chimney-like feature and another resembling the edges of a ruptured bubble. This is the clearest view to date of the base of the kpc-scale dusty wind known in this galaxy. These structures do not extrapolate to a single central point, implying multiple ejection sites for the dust. In general, the distribution of dust probed in the mid-IR anticorrelates with the locations of massive star clusters that appear in the near-infrared. The 10-21 micron mid-IR emission, spatially-integrated over the field of view, may be represented by hot dust with temperature of ~160 K. Most discrete sources are found to have extended morphologies. Several radio HII regions are identified for the first time in the mid-IR. The only potential radio supernova remnant to have a mid-IR counterpart is a source which has previously also been suggested to be a weak active galactic nucleus. This source has an X-ray counterpart in Chandra data which appears prominently above 3 keV and is best described as a hot (~2.6 keV) absorbed thermal plasma with a 6.7 keV Fe K emission line, in addition to a weaker and cooler thermal component. The mid-IR detection is consistent with the presence of strong [NeII]12.81um line emission. The broad-band source properties are complex, but the X-ray spectra do not support the active galactic nucleus hypothesis. We discuss possible interpretations regarding the nature of this source.Comment: Accepted for publication in PASJ Subaru special issue. High resolution version available temporarily at http://www.astro.isas.jaxa.jp/~pgandhi/pgandhi_m82.pd

    Insights on neutrino lensing

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    We discuss the gravitational lensing of neutrinos by astrophysical objects. Unlike photons, neutrinos can cross a stellar core; as a result, the lens quality improves. We also estimate the depletion of the neutrino flux after crossing a massive object and the signal amplification expected. While Uranians alone would benefit from this effect in the Sun, similar effects could be considered for binary systems.Comment: 15 pages, 4 figures, to be published in Phys. Lett.

    Entrepreneurship Education: Engineering a Pracademic Approach

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    Innovation and entrepreneurship are becoming increasingly important as we rely on economies to create jobs around the globe. And yet, considering the myriad and dynamic business environments of the 21st century and ever increasing consumer power, the risk of entrepreneurial activity has increased considerably. Consequently, we need to educate engineers in an innovative manner and fundamentally change the teaching methods, curriculum, and research in entrepreneurship education. Applying the scholarship of teaching and learning (SoTL) to entrepreneurship with similar rigor can increase the odds of being successful engineering entrepreneurs. Still, faculty and administrators of engineering programs are hesitant to introduce courses into an engineering curriculum outside of engineering fundaments. The paradox, however, is that non-core engineering courses including leadership and engineering management can help students develop highly desired attributes that contribute to career and industry success. In this paper, the authors look at current trends in entrepreneurship education and will propose a potential new approach to innovation and entrepreneurship education for engineers in the 21st century. This approach will focus on pracademic (practical / professional and academic) learning concepts that are both engaging and worthwhile for student-centered learning. Supplementary pedagogical approaches are necessary to augment classroom learning for aligning active-learning topics within innovative course frameworks. This new approach will focus on four topics: innovation in teaching methods, introducing leadership education into the entrepreneurship curriculum, quality within systems engineering management, and using rigorous research to drive transformational change in entrepreneurship education. The pracademic approach will be taught as a workshop series or as courses in the entrepreneurship domain and will be presented as part of this paper where methods, leadership, quality, and rigorous research are the central tenets the authors propose for serious and thrivable consideration

    Management of Pain in Children with Burns

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    Burn injuries are common in children under 10 years of age. Thermal injury is the most common mechanism of injury and scalds account for >60% of such injuries. All children with burns will experience pain, regardless of the cause, size, or burn depth. Undertreated pain can result in noncompliance with treatment and, consequently, prolonged healing. It is acknowledged that the monitoring and reporting of pain in children with burns has generally been poor. Due to the adverse physiological and emotional effects secondary to pain, adequate pain control is an integral and requisite component in the management of children with burns. A multidisciplinary approach is frequently necessary to achieve a robust pain relief. Key to successful treatment is the continuous and accurate assessment of pain and the response to therapy. This clinical review article discusses the essential aspects of the pathophysiology of burns in children provides an overview of pain assessment, the salient principles in managing pain, and the essential pharmacodynamics of commonly used drugs in children with burn injuries. Both pharmacological and nonpharmacological treatment options are discussed, although a detailed review of the latter is beyond the scope and remit of this article

    Recital Comparison of Bilingual Language Using Various Filters for Offline Handwritten Character

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    Optical Character Recognition (OCR) of multilingual document containing Offline Handwritten Character (OHC) in regional languages of India, it is necessary to identify different script forms before running an individual OCR of the scripts. In this paper, novel approaches for offline character recognition are written in south Indian languages such as Tamil and Kannada. Preprocessing is one of the most important phases in OCR development. It directly affects the efficiency of any OCR. In this process an extracting of basic constituent symbols of the script. Different methodologies which are growing rapidly in the area of character recognition is South Indian Languages. In this paper, it is mainly focused on the existing methodology used in different stages of OCR to recognize offline handwritten character of bilingual regional languages of South India such as Tamil and Kannada are reviewed, summarized and documented

    A growth-rate indicator for Compton-thick active galactic nuclei

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    Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGN) is difficult to measure. A statistically significant correlation between the Eddington ratio, {\lambda}Edd_{Edd}, and the X-ray power-law index, {\Gamma}, observed in unobscured AGN offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line-of-sight to the central engine is heavily obscured, the recovery of the intrinsic {\Gamma} is challenging. Here we study a sample of local, predominantly Compton-thick megamaser AGN, where the black hole mass, and thus Eddington luminosity, are well known. We compile results on X-ray spectral fitting of these sources with sensitive high-energy (E> 10 keV) NuSTAR data, where X-ray torus models which take into account the reprocessing effects have been used to recover the intrinsic {\Gamma} values and X-ray luminosities, LX_X. With a simple bolometric correction to LX_X to calculate {\lambda}Edd_{Edd}, we find a statistically significant correlation between {\Gamma} and {\lambda}Edd_{Edd} (p = 0.007). A linear fit to the data yields {\Gamma} = (0.41±\pm0.18)log10_{10}{\lambda}Edd_{Edd}+(2.38±\pm 0.20), which is statistically consistent with results for unobscured AGN. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes (MBH106107_{BH}\approx10^6-10^7 Msol_{sol}) and are highly inclined, our results extend the {\Gamma}-{\lambda}Edd_{Edd} relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of {\Gamma} as a growth-rate indicator for accreting black holes, even for Compton-thick AGN.Comment: Accepted for publication in Ap

    NuSTAR Unveils a Compton-thick Type 2 Quasar in Mrk 34

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    We present Nuclear Spectroscopic Telescope Array (NuSTAR) 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM-Newton data can be fitted self-consistently with a reflection-dominated continuum and a strong Fe Kα fluorescence line with equivalent width >1 keV. Prior X-ray spectral fitting below 10 keV showed the source to be consistent with being obscured by Compton-thin column densities of gas along the line of sight, despite evidence for much higher columns from multiwavelength data. NuSTAR now enables a direct measurement of this column and shows that N H lies in the Compton-thick (CT) regime. The new data also show a high intrinsic 2-10 keV luminosity of L 2-10 ~ 1044 erg s–1, in contrast to previous low-energy X-ray measurements where L 2-10 lsim 1043 erg s–1 (i.e., X-ray selection below 10 keV does not pick up this source as an intrinsically luminous obscured quasar). Both the obscuring column and the intrinsic power are about an order of magnitude (or more) larger than inferred from pre-NuSTAR X-ray spectral fitting. Mrk 34 is thus a "gold standard" CT QSO2 and is the nearest non-merging system in this class, in contrast to the other local CT quasar NGC 6240, which is currently undergoing a major merger coupled with strong star formation. For typical X-ray bolometric correction factors, the accretion luminosity of Mrk 34 is high enough to potentially power the total infrared luminosity. X-ray spectral fitting also shows that thermal emission related to star formation is unlikely to drive the observed bright soft component below ~3 keV, favoring photoionization instead

    Splitting neutrino masses and showering into Sky

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    Neutrino masses might be as light as a few time the atmospheric neutrino mass splitting. High Energy ZeV cosmic neutrinos (in Z-Showering model) might hit relic ones at each mass in different resonance energies in our nearby Universe. This non-degenerated density and energy must split UHE Z-boson secondaries (in Z-Burst model) leading to multi injection of UHECR nucleons within future extreme AUGER energy. Secondaries of Z-Burst as neutral gamma, below a few tens EeV are better surviving local GZK cut-off and they might explain recent Hires BL-Lac UHECR correlations at small angles. A different high energy resonance must lead to Glashow's anti-neutrino showers while hitting electrons in matter. In air, Glashow's anti-neutrino showers lead to collimated and directional air-showers offering a new Neutrino Astronomy. At greater energy around PeV, Tau escaping mountains and Earth and decaying in flight are effectively showering in air sky. These Horizontal showering is splitting by geomagnetic field in forked shapes. Such air-showers secondaries release amplified and beamed gamma bursts (like observed TGF), made also by muon and electron pair bundles, with their accompanying rich Cherenkov flashes. Also planet' s largest (Saturn, Jupiter) atmosphere limbs offer an ideal screen for UHE GZK and Z-burst tau neutrino, because their largest sizes. Titan thick atmosphere and small radius are optimal for discovering up-going resonant Glashow resonant showers. Earth detection of Neutrino showering by twin Magic Telescopes on top mountains, or by balloons and satellites arrays facing the limbs are the simplest and cheapest way toward UHE Neutrino Astronomy .Comment: 4 pages, 7 figures; an author's name correction and Journal Referenc

    Improving conventional prognosticators in diffuse large B cell lymphoma using marker ratios

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    Risk stratification for diffuse large B-cell lymphoma (DLBCL) is required as patients with disease may not be cured despite initial R-CHOP treatment. We investigated gene ratio tests to predict survival outcome of DLBCL patients based on the relationship between immune-effector and inhibitory (checkpoint) genes from nanoString™ nCounter in 158 paraffin-embedded DLBCL tissues. We assessed the predictive value of several possible gene ratios using a tree-based survival statistical model, and investigated the predictive value of those gene ratios in an independent R-CHOP treated cohorts of 233 patients. We showed that an immune ratio composed of CD4∗CD8∗:(CD163/CD68)∗PD-L1 was able to stratify overall survival better than single or combination of immune markers, distinguishing groups with disparate 4-year survivals (92% versus 47%). The immune ratio was independent of and added to the revised international prognostic index (R-IPI) and cell-of-origin (COO) and has potential implications for selection of patients for checkpoint-blockade within clinical trials
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