13 research outputs found

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Qualidade industrial do trigo em função do trinexapac-ethyl e doses de nitrogênio Industrial quality of wheat as a function of trinexapac-ethyl and nitrogen doses

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    Objetivou-se, neste trabalho, avaliar a época de aplicação do redutor de crescimento trinexapac-ethyl e de doses de nitrogênio no rendimento de grãos e qualidade industrial das cultivares de trigo Avante e BRS 177. O delineamento experimental foi blocos ao acaso em esquema fatorial 4 x 4, com quatro repetições. Os tratamentos constaram de épocas de aplicação de trinexapac-ethyl (100 g ha-1 entre o primeiro e o segundo nó visível do trigo; 100 g ha-1 entre o segundo e terceiro nó visível; aplicação sequencial de 50 g ha-1 em cada uma das fases anteriores; testemunha sem aplicação) e de doses de nitrogênio em cobertura (90, 135, 180 e 225 kg ha-1 para a cultivar Avante e 60, 80, 120 e 150 kg ha-1 para a cultivar BRS 177). Avaliaram-se características agronômicas, acamamento, componentes de rendimento, rendimento de grãos, qualidade do grão e da farinha. O trinexapac-ethyl, independentemente da época de aplicação, reduziu a estatura das plantas e a porcentagem de acamamento, com resposta diferencial no rendimento de grãos e sem influência substancial na qualidade industrial do trigo. O aumento nas doses de nitrogênio promoveu maior acamamento, afetou a qualidade do grão e da farinha da cultivar BRS 177, mas sem efeitos no rendimento de grãos.<br>The objective of this work was to evaluate the application time of the trinexapac-ethyl growth reducer and of nitrogen rates in the yield and industrial quality of the wheat cultivars Avante and BRS 177. The experimental design was complete randomized blocks in a 4 x 4 factorial scheme, with four replicates. The treatments consisted of periods of trinexapac-ethyl application (100 g ha-1 between the first and second visible node of the wheat; 100 g ha-1 between the second and third visible node; sequential application of 50 g ha-1 in each one of the previous phases; without application) and of nitrogen rates in covering (90, 135, 180 and 225 kg ha-1 for Avante cultivar and 60, 80, 120 and 150 kg ha-1 for BRS 177 cultivar). The following characteristics were evaluated: agronomical characteristic, lodging, yield components, yield, grain and flour quality. Trinexapac-ethyl, independently of the application time, reduced plant height and the lodging percentage, with different response in the yield and without substantial influence on the industrial quality of the wheat. The increase in the nitrogen rates promoted higher lodging, affected the grain and flour quality of BRS 177 cultivar and had no effect on yield

    Bayesian distances and extinctions for giants observed by Kepler and APOGEE

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    We present a first determination of distances and extinctions for individual stars in the first release of the APOKASC catalogue, built from the joint efforts of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and the Kepler Asteroseismic Science Consortium (KASC). Our method takes into account the spectroscopic constraints derived from the APOGEE Stellar Parameters and Chemical Abundances Pipeline, together with the asteroseismic parameters from KASC. These parameters are then employed to estimate intrinsic stellar properties, including absolute magnitudes, using the Bayesian tool PARAM. We then find the distance and extinction that best fit the observed photometry in Sloan Digital Sky Survey (SDSS), 2MASS, and WISE passbands. The first 1989 giants targetted by APOKASC are found at typical distances between 0.5 and 5 kpc, with individual uncertainties of just ∼1.8 per cent. Our extinction estimates are systematically smaller than provided in the Kepler Input Catalogue and by the Schlegel et al. maps. Distances to individual stars in the NGC 6791 and NGC 6819 star clusters agree to within their credible intervals. Comparison with the APOGEE red clump and SAGA catalogues provide another useful check, exhibiting agreement with our measurements to within a few per cent. Overall, present methods seem to provide excellent distance and extinction determinations for the bulk of the APOKASC sample. Approximately one third of the stars present broad or multiple-peaked probability density functions and hence increased uncertainties. Uncertainties are expected to be reduced in future releases of the catalogue, when a larger fraction of the stars will have seismically determined evolutionary status classifications

    Boletín del Servicio Meteorológico Nacional: Epoca 2ª Año VIII Número 191 - 1959 Julio 10

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    We report the discovery of a group of apparently young CoRoT red-giant stars exhibiting enhanced [ /Fe] abundance ratios (as determined from APOGEE spectra) with respect to solar values. Their existence is not explained by standard chemical evolution models of the Milky Way, and shows that the chemical-enrichment history of the Galactic disc is more complex. We find similar stars in previously published samples for which isochrone-ages could be reliably obtained, although in smaller relative numbers. This might explain why these stars have not previously received attention. The young [ /Fe]-rich stars are much more numerous in the CoRoT-APOGEE (CoRoGEE) inner-field sample than in any other high-resolution sample available at present because only CoRoGEE can explore the inner-disc regions and provide ages for its field stars. The kinematic properties of the young [ /Fe]-rich stars are not clearly thick-disc like, despite their rather large distances from the Galactic mid-plane. Our tentative interpretation of these and previous intriguing observations in the Milky Way is that these stars were formed close to the end of the Galactic bar, near corotation – a region where gas can be kept inert for longer times than in other regions that are more frequently shocked by the passage of spiral arms. Moreover, this is where the mass return from older inner-disc stellar generations is expected to be highest (according to an inside-out disc-formation scenario), which additionally dilutes the in-situ gas. Other possibilities to explain these observations (e.g., a recent gas-accretion event) are also discussed

    The eleventh and twelfth data releases of the Sloan Digital Sky Survey : final data from SDSS-III

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    The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new nearinfrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra
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