Institution
National Autonomous University of Mexico
Education•Mexico City, Distrito Federal, Mexico•
About: National Autonomous University of Mexico is a education organization based out in Mexico City, Distrito Federal, Mexico. It is known for research contribution in the topics: Population & Galaxy. The organization has 72868 authors who have published 127797 publications receiving 2285543 citations. The organization is also known as: UNAM & Universidad Nacional Autónoma de México.
Topics: Population, Galaxy, Thin film, Species richness, Catalysis
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the first apparent superluminal motion was detected in a source within our own Galaxy and the optical, infrared and X-ray properties suggest that the source is either a neutron star or a black hole that is ejecting matter in a process similar to, but on a smaller scale than that seen in quasars.
Abstract: APPARENT velocities greater than the speed of light (superluminal motion) have been inferred for radio-emitting components in a number of distant quasars and active galactic nuclei1. These components move away from the central sources (generally thought to be super-massive black holes) at rates that seem to imply velocities greater than c. The accepted explanation is that clouds of plasma are ejected in opposite directions from the central source at speeds close to (but less than) that of light, and that relativistic effects lead to the apparent superluminal motion2. But the extreme distance of the objects observed so far introduces many uncertainties into this interpretation3. Here we present observations of the first apparent superluminal motion ever detected in a source within our own Galaxy. The optical, infrared and X-ray properties4,5 of the counterpart suggest that the source is either a neutron star or a black hole that is ejecting matter in a process similar to, but on a smaller scale than that seen in quasars. Because of its relative proximity, this superluminal microquasar may offer the best opportunity to gain a general understanding of relativistic ejections seen elsewhere in the Universe.
1,161 citations
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TL;DR: The dimensions and nature of the Earth's terrestrial biodiversity are examined, and the scientific facts concerning the rate of loss of biodiversity and the drivers of this loss are reviewed.
Abstract: ▪ Abstract Biodiversity, a central component of Earth's life support systems, is directly relevant to human societies. We examine the dimensions and nature of the Earth's terrestrial biodiversity and review the scientific facts concerning the rate of loss of biodiversity and the drivers of this loss. The estimate for the total number of species of eukaryotic organisms possible lies in the 5–15 million range, with a best guess of ∼7 million. Species diversity is unevenly distributed; the highest concentrations are in tropical ecosystems. Endemisms are concentrated in a few hotspots, which are in turn seriously threatened by habitat destruction—the most prominent driver of biodiversity loss. For the past 300 years, recorded extinctions for a few groups of organisms reveal rates of extinction at least several hundred times the rate expected on the basis of the geological record. The loss of biodiversity is the only truly irreversible global environmental change the Earth faces today.
1,157 citations
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TL;DR: This work demonstrates the first observation of electrical control of antiferromagnetic domain structure in a single-phase multiferroic material at room temperature with high resolution images, indicating a strong coupling between the two types of order.
Abstract: Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. In this work, we demonstrate the first observation of electrical control of antiferromagnetic domain structure in a single-phase multiferroic material at room temperature. High-resolution images of both antiferromagnetic and ferroelectric domain structures of (001)-oriented multiferroic BiFeO3 films revealed a clear domain correlation, indicating a strong coupling between the two types of order. The ferroelectric structure was measured using piezo force microscopy, whereas X-ray photoemission electron microscopy as well as its temperature dependence was used to detect the antiferromagnetic configuration. Antiferromagnetic domain switching induced by ferroelectric polarization switching was observed, in agreement with theoretical predictions.
1,147 citations
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University of Erlangen-Nuremberg1, University of Zaragoza2, University of Cambridge3, University College London4, Pennsylvania State University5, University of Texas at Austin6, Vrije Universiteit Brussel7, Open University8, Imperial College London9, University of Münster10, University of Vienna11, Tohoku University12, Mexican Institute of Petroleum13, Natural Resources Canada14, Denver Museum of Nature and Science15, Humboldt University of Berlin16, Universities Space Research Association17, University of Missouri18, Chiba Institute of Technology19, Purdue University20, University of Notre Dame21, University of California, San Diego22, Planetary Science Institute23, Katholieke Universiteit Leuven24, National Autonomous University of Mexico25, Lund University26, University of Alaska Fairbanks27
TL;DR: Records of the global stratigraphy across this boundary are synthesized to assess the proposed causes of the Cretaceous-Paleogene boundary and conclude that the Chicxulub impact triggered the mass extinction.
Abstract: The Cretaceous-Paleogene boundary similar to 65.5 million years ago marks one of the three largest mass extinctions in the past 500 million years. The extinction event coincided with a large asteroid impact at Chicxulub, Mexico, and occurred within the time of Deccan flood basalt volcanism in India. Here, we synthesize records of the global stratigraphy across this boundary to assess the proposed causes of the mass extinction. Notably, a single ejecta-rich deposit compositionally linked to the Chicxulub impact is globally distributed at the Cretaceous-Paleogene boundary. The temporal match between the ejecta layer and the onset of the extinctions and the agreement of ecological patterns in the fossil record with modeled environmental perturbations (for example, darkness and cooling) lead us to conclude that the Chicxulub impact triggered the mass extinction.
1,135 citations
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Daniel J. Klionsky1, Amal Kamal Abdel-Aziz2, Sara Abdelfatah3, Mahmoud Abdellatif4 +2980 more•Institutions (777)
TL;DR: In this article, the authors present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes.
Abstract: In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.
1,129 citations
Authors
Showing all 73617 results
Name | H-index | Papers | Citations |
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Richard Peto | 183 | 683 | 231434 |
Anton M. Koekemoer | 168 | 1127 | 106796 |
Rory Collins | 162 | 489 | 193407 |
Timothy C. Beers | 156 | 934 | 102581 |
Vivek Sharma | 150 | 3030 | 136228 |
Kjell Fuxe | 142 | 1479 | 89846 |
Prashant V. Kamat | 140 | 725 | 79259 |
Carmen García | 139 | 1503 | 96925 |
Harold A. Mooney | 135 | 450 | 100404 |
Efe Yazgan | 128 | 986 | 79041 |
Roberto Maiolino | 127 | 816 | 61724 |
Peter Nugent | 127 | 754 | 92988 |
William R. Miller | 125 | 601 | 72570 |
Nicholas A. Kotov | 123 | 574 | 55210 |
John C. Wingfield | 122 | 509 | 52291 |