Institution
Universidad de las Américas Puebla
Education•San Andrés Cholula, Mexico•
About: Universidad de las Américas Puebla is a education organization based out in San Andrés Cholula, Mexico. It is known for research contribution in the topics: Population & Government. The organization has 2689 authors who have published 4323 publications receiving 51584 citations. The organization is also known as: Universidad de las Americas Puebla.
Topics: Population, Government, Latin Americans, Usability, Public sector
Papers published on a yearly basis
Papers
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TL;DR: In this article, the Event Horizon Telescope was used to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87.
Abstract: When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 +/- 3 mu as, which is circular and encompasses a central depression in brightness with a flux ratio greater than or similar to 10: 1. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. We compare our images to an extensive library of ray-traced general-relativistic magnetohydrodynamic simulations of black holes and derive a central mass of M = (6.5 +/- 0.7) x 10(9) M-circle dot. Our radio-wave observations thus provide powerful evidence for the presence of supermassive black holes in centers of galaxies and as the central engines of active galactic nuclei. They also present a new tool to explore gravity in its most extreme limit and on a mass scale that was so far not accessible.
2,589 citations
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National University of Río Negro1, University of Würzburg2, Rutgers University3, National University of Comahue4, Swedish University of Agricultural Sciences5, Commonwealth Scientific and Industrial Research Organisation6, University of California, Berkeley7, University of Leeds8, Naturalis9, University of Calgary10, Hebrew University of Jerusalem11, Lüneburg University12, ETH Zurich13, National University of Tucumán14, Federal University of Ceará15, Federal University of Bahia16, Plant & Food Research17, Michigan State University18, Agriculture and Agri-Food Canada19, The Nature Conservancy20, University of Göttingen21, University of Queensland22, Cornell University23, University of Reading24, Stockholm University25, University of Vermont26, Lund University27, University of Koblenz and Landau28, University of Bern29, Jagiellonian University30, Universidad de las Américas Puebla31, University of California, Davis32
TL;DR: Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation.
Abstract: The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.
1,881 citations
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TL;DR: The extent of the trait data compiled in TRY is evaluated and emerging patterns of data coverage and representativeness are analyzed to conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements.
Abstract: Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
882 citations
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TL;DR: The Event Horizon Telescope (EHT) as mentioned in this paper is a very long baseline interferometry (VLBI) array that comprises millimeter and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth.
Abstract: The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64 gigabit s^(−1), exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.
756 citations
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University of New England (Australia)1, Spanish National Research Council2, National University of Río Negro3, University of Reading4, Plant & Food Research5, Rutgers University6, Commonwealth Scientific and Industrial Research Organisation7, University of Queensland8, Australian Bureau of Agricultural and Resource Economics9, Lund University10, Swedish University of Agricultural Sciences11, University of California, Davis12, University of Lisbon13, Naturalis14, University of Brasília15, National University of Tucumán16, University of Koblenz and Landau17, Federal University of Ceará18, United Nations19, ETH Zurich20, Federal University of Bahia21, University of Giessen22, University of Freiburg23, Wageningen University and Research Centre24, American Museum of Natural History25, Hebrew University of Jerusalem26, University of Bern27, Trinity College, Dublin28, Royal Holloway, University of London29, University of Agriculture, Faisalabad30, Jagiellonian University31, Universidad de las Américas Puebla32
TL;DR: It is shown that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use.
Abstract: Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.
620 citations
Authors
Showing all 2702 results
Name | H-index | Papers | Citations |
---|---|---|---|
Thomas Heine | 84 | 423 | 24210 |
Cristina M. Rosell | 70 | 275 | 14509 |
Patrick J. Walsh | 56 | 391 | 11449 |
Maciej A. Zwieniecki | 51 | 134 | 8280 |
Clémence Corminboeuf | 49 | 214 | 9932 |
Carlos A. Martínez-Huitle | 49 | 252 | 12381 |
Aurelio López-Malo | 45 | 219 | 6398 |
Gabriel Merino | 44 | 238 | 6533 |
J. Ramon Gil-Garcia | 39 | 256 | 8942 |
Enrique Palou | 37 | 168 | 4427 |
Alberto Vela | 36 | 144 | 4214 |
Oscar Rodríguez | 36 | 108 | 3466 |
Jorge Welti-Chanes | 36 | 228 | 4824 |
Guillermo J. Ruiz-Argüelles | 34 | 282 | 4375 |
José M. Alvarez-Suarez | 33 | 81 | 4905 |