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    JournalThe Astrophysical Journal (299)ASTROPHYSICAL JOURNAL (227)PLOS ONE (140)Monthly Notices of the Royal Astronomical Society (128)MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (123)The Astronomical Journal (82)ASTRONOMICAL JOURNAL (66)PHYSICAL REVIEW D (65)Scientific Reports (65)SCIENTIFIC REPORTS (55)View MoreAuthorsUniv Arizona, Steward Observ (781)Univ Arizona, Coll Opt Sci (383)Univ Arizona, Lunar & Planetary Lab (363)Univ Arizona, Dept Phys (330)Univ Arizona (285)Univ Arizona, Dept Astron (206)Univ Arizona, Dept Geosci (184)Univ Arizona, Dept Hydrol & Atmospher Sci (166)Univ Arizona, Dept Ecol & Evolutionary Biol (138)Univ Arizona, Sch Nat Resources & Environm (134)View MoreTypes
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    ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE

    García Pérez, Ana E.; Prieto, Carlos Allende; Holtzman, J.; Shetrone, Matthew; Mészáros, Szabolcs; Bizyaev, Dmitry; Carrera, Ricardo; Cunha, Katia; García-Hernández, D. A.; Johnson, Jennifer A.; et al. (IOP PUBLISHING LTD, 2016-05-23)
    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R approximate to 22,500) spectroscopic map of the stars across the Milky Way, and including dust-obscured areas. The APOGEE Stellar Parameter and Chemical Abundances Pipeline (ASPCAP) is the software developed for the automated analysis of these spectra. ASPCAP determines atmospheric parameters and chemical abundances from observed spectra by comparing observed spectra to libraries of theoretical spectra, using. 2 minimization in a multidimensional parameter space. The package consists of a FORTRAN90 code that does the actual minimization and a wrapper IDL code for book-keeping and data handling. This paper explains in detail the ASPCAP components and functionality, and presents results from a number of tests designed to check its performance. ASPCAP provides stellar effective temperatures, surface gravities, and metallicities precise to 2%, 0.1 dex, and 0.05 dex, respectively, for most APOGEE stars, which are predominantly giants. It also provides abundances for up to 15 chemical elements with various levels of precision, typically under 0.1 dex. The final data release (DR12) of the Sloan Digital Sky Survey III contains an APOGEE database of more than 150,000 stars. ASPCAP development continues in the SDSS-IV APOGEE-2 survey.
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    The First Post-Kepler Brightness Dips of KIC 8462852

    Boyajian, Tabetha. S.; Alonso, Roi; Ammerman, Alex; Armstrong, David; Ramos, A. Asensio; Barkaoui, K.; Beatty, Thomas G.; Benkhaldoun, Z.; Benni, Paul; O. Bentley, Rory; et al. (IOP PUBLISHING LTD, 2018-01-19)
    We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and " Angkor," which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale << 1 mu m, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process.
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    Optimum air temperature for tropical forest photosynthesis: mechanisms involved and implications for climate warming

    Tan, Zheng-Hong; Zeng, Jiye; Zhang, Yong-Jiang; Slot, Martijn; Gamo, Minoru; Hirano, Takashi; Kosugi, Yoshiko; da Rocha, Humberto R; Saleska, Scott R; Goulden, Michael L; et al. (IOP PUBLISHING LTD, 2017-05-01)
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    Measurement of the four-lepton invariant mass spectrum in 13 TeV proton-proton collisions with the ATLAS detector

    Berlendis, S.; Cheu, E.; Delitzsch, C. M.; Johns, K. A.; Jones, S.; Lampl, W.; LeBlanc, M.; Leone, R.; Loch, P.; Nayyar, R.; et al. (SPRINGER, 2019-04-05)
    A measurement of the four-lepton invariant mass spectrum is made with the ATLAS detector, using an integrated luminosity of 36.1 fb(-1) of proton-proton collisions at root s = 13 TeV delivered by the Large Hadron Collider. The differential cross-section is measured for events containing two same-flavour opposite-sign lepton pairs. It exhibits a rich structure, with different mass regions dominated in the Standard Model by single Z boson production, Higgs boson production, and Z boson pair production, and non-negligible interference effects at high invariant masses. The measurement is compared with state-of-the-art Standard Model calculations, which are found to be consistent with the data. These calculations are used to interpret the data in terms of gg -> ZZ -> 4l and Z -> 4l subprocesses, and to place constraints on a possible contribution from physics beyond the Standard Model.
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    Tree Mortality Decreases Water Availability and Ecosystem Resilience to Drought in Piñon-Juniper Woodlands in the Southwestern U.S.

    Morillas, L.; Pangle, R. E.; Maurer, G. E.; Pockman, W. T.; McDowell, N.; Huang, C.-W.; Krofcheck, D. J.; Fox, Andrew; Sinsabaugh, R. L.; Rahn, T. A.; et al. (AMER GEOPHYSICAL UNION, 2017-12)
    Climate-driven tree mortality has increased globally in response to warmer temperature and more severe drought. To examine how tree mortality in semiarid biomes impacts surface water balance, we experimentally manipulated a pinon-juniper (PJ) woodland by girdling all adult pinon trees in a 4 ha area, decreasing pinon basal area by similar to 65%. Over 3.5 years (2009-2013), we compared water flux measurements from this girdled site with those from a nearby intact PJ woodland. Before and after girdling, the ratio of evapotranspiration (ET) to incoming precipitation was similar between the two sites. Girdling altered the partitioning of ET such that the contribution of canopy transpiration to ET decreased 9-14% over the study period, relative to the intact control, while noncanopy ET increased. We attributed the elevated noncanopy ET in the girdled site each year to winter increases in sublimation and summer increases in both soil evaporation and below-canopy transpiration. Although we expected that mortality of a canopy dominant would increase the availability of water and other resources to surviving vegetation, we observed a decrease in both soil volumetric water content and sap flow rates in the remaining trees at the girdled site, relative to the control. This postgirdling decrease in the performance of the remaining trees occurred during the severe 2011-2012 drought, suggesting that pinon mortality may trigger feedback mechanisms that leave PJ woodlands drier relative to undisturbed sites and potentially more vulnerable to drought.
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    TDP-43 pathology disrupts nuclear pore complexes and nucleocytoplasmic transport in ALS/FTD

    Chou, Ching-Chieh; Zhang, Yi; Umoh, Mfon E.; Vaughan, Spencer W.; Lorenzini, Ileana; Liu, Feilin; Sayegh, Melissa; Donlin-Asp, Paul G.; Chen, Yu Han; Duong, Duc M.; et al. (NATURE PUBLISHING GROUP, 2018-02)
    The cytoplasmic mislocalization and aggregation of TAR DNA-binding protein-43 (TDP-43) is a common histopathological hallmark of the amyotrophic lateral sclerosis and frontotemporal dementia disease spectrum (ALS/FTD). However, the composition of aggregates and their contribution to the disease process remain unknown. Here we used proximity-dependent biotin identification (BioID) to interrogate the interactome of detergent-insoluble TDP-43 aggregates and found them enriched for components of the nuclear pore complex and nucleocytoplasmic transport machinery. Aggregated and disease-linked mutant TDP-43 triggered the sequestration and/or mislocalization of nucleoporins and transport factors, and interfered with nuclear protein import and RNA export in mouse primary cortical neurons, human fibroblasts and induced pluripotent stem cell-derived neurons. Nuclear pore pathology is present in brain tissue in cases of sporadic ALS and those involving genetic mutations in TARDBP and C9orf72. Our data strongly implicate TDP-43-mediated nucleocytoplasmic transport defects as a common disease mechanism in ALS/FTD.
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    Aerosol Retrievals from CALIPSO Lidar Ocean Surface Returns

    Venkata, Srikanth; Reagan, John (MDPI AG, 2016-12-09)
    This paper describes approaches to retrieve important aerosol results from the strong lidar return signals that are received by the space-borne CALIPSO lidar system after reflecting off-ocean surfaces. Relations, from which the theoretically expected values of area under ocean surface returns can be computed, are presented. A detailed description of the lidar system response to the ocean surface returns and the processes of sampling and averaging of lidar return signals are provided. An effective technique that reconstructs the lidar response to surface returnsstarting from down-linked samplesand calculates the area under it, has been developed and described. The calculated area values are validated after comparing them to their theoretically predicted counterpart values. Methods to retrieve aerosol optical depths (AODs) from these calculated areas are described and retrieval results are presented, including retrieval comparison with independent AOD measurements made by an airborne High Spectral Resolution Lidar (HSRL) that yielded quite good agreement. Techniques and results are also presented on using the spectral ratios of the surface response areas to determine spectral ratios of aerosol round-trip transmission and AOD spectral difference, without need of a specific/accurate ocean-surface reflectance model.
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    SEEDS DIRECT IMAGING OF THE RV-DETECTED COMPANION TO V450 ANDROMEDAE, AND CHARACTERIZATION OF THE SYSTEM

    Hełminiak, K. G.; Kuzuhara, M.; Mede, K.; Brandt, T. D.; Kandori, R.; Suenaga, T.; Kusakabe, N.; Narita, N.; Carson, J. C.; Currie, T.; et al. (IOP PUBLISHING LTD, 2016-11-14)
    We report the direct imaging detection of a low-mass companion to a young, moderately active star V450. And, that was previously identified with the radial velocity (RV) method. The companion was found in high-contrast images obtained with the Subaru Telescope equipped with the HiCIAO camera and AO188 adaptive optics system. From the public ELODIE and SOPHIE archives we extracted available high-resolution spectra and RV measurements, along with RVs from the Lick planet search program. We combined our multi-epoch astrometry with these archival, partially unpublished RVs, and found that the companion is a low-mass star, not a brown dwarf, as previously suggested. We found the best-fitting dynamical masses to be m(1) = 1.141(-0.091)(+0.037)and m(2) = 0.279(-0.020)(+0.023) M-circle dot. We also performed spectral analysis of the SOPHIE spectra with the iSpec code. Hipparcos time-series photometry shows a periodicity of P = 5.743 day, which is also seen in the SOPHIE spectra as an RV modulation of the star A. We interpret it as being caused by spots on the stellar surface, and the star to be rotating with the given period. From the rotation and level of activity, we found that the system is 380(-100)(+220) Myr old, consistent with an isochrone analysis (220(-90)(+2120) Myr). This work may serve as a test case for future studies of low-mass stars, brown dwarfs, and exoplanets by combination of RV and direct imaging data.
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    A quest for sacred knowledge: Mentorship to partnership

    Black, Rebecka; Garber, Elizabeth; Neff, YuWen Eryn; Sharma, Manisha (INTELLECT LTD, 2016-12)
    Faced with the challenge of developing a mentorship relationship between faculty and graduate students that would result in a partnership, intrepid scholars Becky, Elizabeth, Eryn and Manisha encounter uncertainty, disillusionment and teaching obstacles. Optimism is followed, in their working process, by a search for a meaningful focus for the collaboration that charts new territory and simultaneously captures the interest of each scholar. Beginning with the broad theme of technological tools in teaching, they move to the educational use of video games and settle on the concept of play. Their persistence leads to a change of mission, one that grows out of their mutual work and discussions together, and commitment to their roles in a supportive partnership that involves a 'community of practice' (Wenger et al. 2002). The trust this establishes allows for a questioning of the concept of Sacred Knowledge in Academia during the writing process.
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    A Detailed Observational Analysis of V1324 Sco, the Most Gamma-Ray-luminous Classical Nova to Date

    Finzell, Thomas; Chomiuk, Laura; Metzger, Brian D.; Walter, Frederick M.; Linford, Justin D.; Mukai, Koji; Nelson, Thomas; Weston, Jennifer H. S.; Zheng, Yong; Sokoloski, Jennifer L.; et al. (IOP PUBLISHING LTD, 2018-01-12)
    It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst, but the mechanisms involved in the production ofgamma-rays are still not well understood. We present here a comprehensive multiwavelength data set-from radio to X-rays-for the most gamma-ray-luminous classical nova to date, V1324 Sco. Using this data set, we show that V1324 Sco is a canonical dusty Fe II-type nova, with a maximum ejecta velocity of 2600 km s(-1) and an ejecta mass of a few x 10(-5) M-circle dot. There is also evidence for complex shock interactions, including a double-peaked radio light curve which shows high brightness temperatures at early times. To explore why V1324. Sco was so gamma-ray luminous, we present a model of the nova ejecta featuring strong internal shocks and find that higher gamma-ray luminosities result from higher ejecta velocities and/or mass-loss rates. Comparison of V1324. Sco with other gamma-ray-detected novae does not show clear signatures of either, and we conclude that a larger sample of similarly well-observed novae is needed to understand the origin and variation of gamma-rays in novae.
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