1,726 research outputs found

    Interferometric imaging of the high-redshift radio galaxy, 4C60.07: An SMA, Spitzer and VLA study reveals a binary AGN/starburst

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Blackwell / RAS. DOI: 10.1111/j.1365-2966.2008.13811.xPeer reviewe

    Star-Like Micelles with Star-Like Interactions: A quantitative Evaluation of Structure Factor and Phase Diagram

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    PEP-PEO block copolymer micelles offer the possibility to investigate phase behaviour and interactions of star polymers (ultra-soft colloids). A star-like architecture is achieved by an extremely asymmetric block ratio (1:20). Micellar functionality f can be smoothly varied by changing solvent composition (interfacial tension). Structure factors obtained by SANS can be quantitatively described in terms of an effective potential developed for star polymers. The experimental phase diagram reproduces to a high level of accuracy the predicted liquid/solid transition. Whereas for intermediate f a bcc phase is observed, for high f the formation of a fcc phase is preempted by glass formation.Comment: 5 pages, 4 figures, PRL in pres

    Coherent electronic and nuclear dynamics in a rhodamine heterodimer-DNA supramolecular complex

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    Elucidating the role of quantum coherences in energy migration within biological and artificial multichromophoric antenna systems is the subject of an intense debate. It is also a practical matter because of the decisive implications for understanding the biological processes and engineering artificial materials for solar energy harvesting. A supramolecular rhodamine heterodimer on a DNA scaffold was suitably engineered to mimic the basic donor-acceptor unit of light-harvesting antennas. Ultrafast 2D electronic spectroscopic measurements allowed identifying clear features attributable to a coherent superposition of dimer electronic and vibrational states contributing to the coherent electronic charge beating between the donor and the acceptor. The frequency of electronic charge beating is found to be 970 cm-1 (34 fs) and can be observed for 150 fs. Through the support of high level ab initio TD-DFT computations of the entire dimer, we established that the vibrational modes preferentially optically accessed do not drive subsequent coupling between the electronic states on the 600 fs of the experiment. It was thereby possible to characterize the time scales of the early time femtosecond dynamics of the electronic coherence built by the optical excitation in a large rigid supramolecular system at a room temperature in solution. © 2017 the Owner Societies.Multi valued and parallel molecular logi

    Indicators of the need for ICU admission following suicide bombing attacks

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    <p>Abstract</p> <p>Introduction</p> <p>Critical hospital resources, especially the demand for ICU beds, are usually limited following mass casualty incidents such as suicide bombing attacks (SBA). Our primary objective was to identify easily diagnosed external signs of injury that will serve as indicators of the need for ICU admission. Our secondary objective was to analyze under- and over-triage following suicidal bombing attacks.</p> <p>Methods</p> <p>A database was collected prospectively from patients who were admitted to Hadassah University Hospital Level I Trauma Centre, Jerusalem, Israel from August 2001-August 2005 following a SBA. One hundred and sixty four victims of 17 suicide bombing attacks were divided into two groups according to ICU and non-ICU admission.</p> <p>Results</p> <p>There were 86 patients in the ICU group (52.4%) and 78 patients in the non-ICU group (47.6%). Patients in the ICU group required significantly more operating room time compared with patients in the non-ICU group (59.3% vs. 25.6%, respectively, <it>p </it>= 0.0003). For the ICU group, median ICU stay was 4 days (IQR 2 to 8.25 days). On multivariable analysis only the presence of facial fractures (<it>p </it>= 0.014), peripheral vascular injury (<it>p </it>= 0.015), injury ≥ 4 body areas (<it>p </it>= 0.002) and skull fractures (<it>p </it>= 0.017) were found to be independent predictors of the need for ICU admission. Sixteen survivors (19.5%) in the ICU group were admitted to the ICU for one day only (ICU-LOS = 1) and were defined as over-triaged. Median ISS for this group was significantly lower compared with patients who were admitted to the ICU for > 1 day (ICU-LOS > 1). This group of over-triaged patients could not be distinguished from the other ICU patients based on external signs of trauma. None of the patients in the non-ICU group were subsequently transferred to the ICU.</p> <p>Conclusions</p> <p>Our results show that following SBA, injury to ≥ 4 areas, and certain types of injuries such as facial and skull fractures, and peripheral vascular injury, can serve as surrogates of severe trauma and the need for ICU admission. Over-triage rates following SBA can be limited by a concerted, focused plan implemented by dedicated personnel and by the liberal utilization of imaging studies.</p

    S-CANDELS: The Spitzer-Cosmic Assembly Near-Infrared Deep Extragalactic Survey. Survey Design, Photometry, and Deep IRAC Source Counts

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    The Spitzer-Cosmic Assembly Deep Near-Infrared Extragalactic Legacy Survey (S-CANDELS; PI G. Fazio) is a Cycle 8 Exploration Program designed to detect galaxies at very high redshifts (z > 5). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope Multi-Cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS) by increasing the integration time from 12 hours to a total of 50 hours but within a smaller area, 0.16 square degrees. The additional depth significantly increases the survey completeness at faint magnitudes. This paper describes the S-CANDELS survey design, processing, and publicly-available data products. We present IRAC dual-band 3.6+4.5 micron catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135,000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.Comment: 23 pages, 19 figures, accepted by ApJ

    The Most Luminous z~9-10 Galaxy Candidates yet Found: The Luminosity Function, Cosmic Star-Formation Rate, and the First Mass Density Estimate at 500 Myr

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    [abridged] We present the discovery of four surprisingly bright (H_160 ~ 26 - 27 mag AB) galaxy candidates at z~9-10 in the complete HST CANDELS WFC3/IR GOODS-N imaging data, doubling the number of z~10 galaxy candidates that are known, just ~500 Myr after the Big Bang. Two similarly bright sources are also detected in a systematic re-analysis of the GOODS-S data set. Three of the four galaxies in GOODS-N are significantly detected at 4.5-6.2sigma in the very deep Spitzer/IRAC 4.5 micron data, as is one of the GOODS-S candidates. Furthermore, the brightest of our candidates (at z=10.2+-0.4) is robustly detected also at 3.6 micron (6.9sigma), revealing a flat UV spectral energy distribution with a slope beta=-2.0+-0.2, consistent with demonstrated trends with luminosity at high redshift. The abundance of such luminous candidates suggests that the luminosity function evolves more significantly in phi_* than in L_* at z>~8 with a higher number density of bright sources than previously expected. Despite the discovery of these luminous candidates, the cosmic star formation rate density for galaxies with SFR >0.7 M_sun/yr shows an order-of-magnitude increase in only 170 Myr from z ~ 10 to z ~ 8, consistent with previous results. Based on the IRAC detections, we derive galaxy stellar masses at z~10, finding that these luminous objects are typically 10^9 M_sun. The cosmic stellar mass density at z~10 is log10 rho_* = 4.7^+0.5_-0.8 M_sun Mpc^-3 for galaxies brighter than M_UV~-18. The remarkable brightness, and hence luminosity, of these z~9-10 candidates highlights the opportunity for deep spectroscopy to determine their redshift and nature, demonstrates the value of additional search fields covering a wider area to understand star-formation in the very early universe, and highlights the opportunities for JWST to map the buildup of galaxies at redshifts much earlier than z~10.Comment: 20 pages, 12 figures, changed to match resubmitted version to Ap
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