Institution
Catholic University of the North
Education•Antofagasta, Chile•
About: Catholic University of the North is a education organization based out in Antofagasta, Chile. It is known for research contribution in the topics: Population & Stars. The organization has 2843 authors who have published 5935 publications receiving 95747 citations. The organization is also known as: Universitaria Católica del Norte.
Topics: Population, Stars, Context (language use), Galaxy, Globular cluster
Papers published on a yearly basis
Papers
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TL;DR: This review of 68 studies compares the methodologies used for the identification and quantification of microplastics from the marine environment and suggests standardized sampling procedures which allow the spatiotemporal comparison ofmicroplastic abundance across marine environments.
Abstract: This review of 68 studies compares the methodologies used for the identification and quantification of microplastics from the marine environment. Three main sampling strategies were identified: selective, volume-reduced, and bulk sampling. Most sediment samples came from sandy beaches at the high tide line, and most seawater samples were taken at the sea surface using neuston nets. Four steps were distinguished during sample processing: density separation, filtration, sieving, and visual sorting of microplastics. Visual sorting was one of the most commonly used methods for the identification of microplastics (using type, shape, degradation stage, and color as criteria). Chemical and physical characteristics (e.g., specific density) were also used. The most reliable method to identify the chemical composition of microplastics is by infrared spectroscopy. Most studies reported that plastic fragments were polyethylene and polypropylene polymers. Units commonly used for abundance estimates are “items per m2” ...
3,119 citations
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TL;DR: The total number of plastic particles and their weight floating in the world's oceans is estimated from 24 expeditions across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows and visual survey transects of large plastic debris.
Abstract: Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world’s oceans from 24 expeditions (2007–2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N5680) and visual survey transects of large plastic debris (N5891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic ,4.75 mm and meso- and macroplastic .4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove ,4.75 mm plastic particles from the ocean surface.
3,091 citations
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TL;DR: A global species-level compilation of key attributes for all 9993 and 5400 extant bird and mammal species derived from key literature sources enables a much finer distinction of species' foraging ecology than typical categorical guild assignments allow.
Abstract: Species are characterized by physiological, behavioral, and ecological attributes that are all subject to varying evolutionary and ecological constraints and jointly determine species' role and function in ecosystems. Attributes such as diet, foraging strata, foraging time, and body size, in particular, characterize a large portion of the “Eltonian” niches of species. Here we present a global species-level compilation of these key attributes for all 9993 and 5400 extant bird and mammal species derived from key literature sources. Global handbooks and monographs allowed the consistent sourcing of attributes for most species. For diet and foraging stratum we followed a defined protocol to translate the verbal descriptions into standardized, semiquantitative information about relative importance of different categories. Together with body size (continuous) and activity time (categorical) this enables a much finer distinction of species' foraging ecology than typical categorical guild assignments allow. Attri...
1,116 citations
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Romina Ahumada1, Carlos Allende Prieto2, Carlos Allende Prieto3, Andres Almeida4 +342 more•Institutions (94)
TL;DR: The most recent data release from the Sloan Digital Sky Surveys (SDSS-IV) is DR16 as mentioned in this paper, which is the fourth and penultimate from the fourth phase of the survey.
Abstract: This paper documents the sixteenth data release (DR16) from the Sloan Digital Sky Surveys; the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the southern hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey (TDSS) and new data from the SPectroscopic IDentification of ERosita Survey (SPIDERS) programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).
803 citations
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Carnegie Institution for Science1, University of California, Santa Cruz2, Carnegie Learning3, University of California, Berkeley4, Lawrence Berkeley National Laboratory5, Pennsylvania State University6, University of Copenhagen7, Johns Hopkins University8, Space Telescope Science Institute9, California Institute of Technology10, Massachusetts Institute of Technology11, Diego Portales University12, Joint Institute for Nuclear Astrophysics13, University of Notre Dame14, National Autonomous University of Mexico15, University of La Serena16, University of Victoria17, Herzberg Institute of Astrophysics18, Valparaiso University19, Texas A&M University20, Catholic University of the North21, Millennium Institute22, University of Sydney23
TL;DR: In this paper, the authors present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days post-merger, showing that the late-time light curve indicates that SSS 17a produced at least 0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.
Abstract: On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.
582 citations
Authors
Showing all 2866 results
Name | H-index | Papers | Citations |
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Keivan G. Stassun | 72 | 934 | 53011 |
Anthony J. Cleare | 60 | 281 | 13190 |
Alan M. Friedlander | 54 | 197 | 10366 |
Elsa E. Cleland | 53 | 94 | 19294 |
S. P. Littlefair | 52 | 293 | 14529 |
Martin Thiel | 50 | 248 | 13514 |
Helga Guderley | 49 | 154 | 7081 |
Lohengrin A. Cavieres | 48 | 205 | 9505 |
Manuel Prieto | 47 | 218 | 7896 |
Gonzalo Alvarez | 44 | 186 | 7454 |
Christian Nitschelm | 42 | 125 | 11343 |
Bernard Rimé | 42 | 148 | 7800 |
Rolf Chini | 42 | 294 | 8069 |
José G. Fernández-Trincado | 42 | 199 | 12098 |
Mahmood S. Shivji | 41 | 139 | 5674 |