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Author (up) Harrison, R.; Hernandez, G.; Munoz, R.
Title A discrete model of market interaction in the presence of social networks and price discrimination Type
Year 2019 Publication Mathematical Social Sciences Abbreviated Journal Math. Soc. Sci.
Volume 102 Issue Pages 48-58
Keywords Social networks; Agent-based models; Price discrimination
Abstract In this paper, we provide a model to study the equilibrium outcome in a market characterized by the competition between two firms offering horizontally differentiated services, in a context where consumers are the basic unit of decision on the demand side and are related through a social network. In the model, we consider that consumers make optimal choice, participation and consumption decisions, while firms optimally decide their tariffs, eventually using nonlinear pricing schemes. This approach permits us to identify and model two different kinds of network externalities, one associated with tariff-mediated network externalities and the other related to participation network externalities. We apply the model to the telecommunication industry, where we study the impact of alternative regulatory interventions. We provide numerical evidence suggesting that policies designed to reduce horizontal differentiation might be more effective than those designed to limit access charges; this result seems robust to the presence of different forms of price discrimination. We should interpret these findings cautiously due to the existence of potential implementation costs for each policy. (C) 2019 Elsevier B.V. All rights reserved.
Address [Harrison, Rodrigo] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: rodrigo.harrison@uai.cl;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0165-4896 ISBN Medium
Area Expedition Conference
Notes WOS:000500049400006 Approved
Call Number UAI @ eduardo.moreno @ Serial 1077
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Author (up) Ko, Y.; Peng, E.W.; Cote, P.; Ferrarese, L.; Liu, C.Z.; Longobardi, A.; Lancon, A.; Munoz, R.P.; Puzia, T.H.; Alamo-Martinez, K.A.; Sales, L.V.; Ramos-Almendares, F.; Abadi, M.G.; Lee, M.G.; Hwang, H.S.; Caldwell, N.; Blakeslee, J.P.; Boselli, A.; Cuillandre, J.C.; Duc, P.A.; Eyheramendy, S.; Guhathakurta, P.; Gwyn, S.; Jordan, A.; Lim, S.; Sanchez-Janssen, R.; Toloba, E.
Title The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System Type
Year 2022 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 931 Issue 2 Pages 120
Keywords EARLY-TYPE GALAXIES; SPACE-TELESCOPE OBSERVATIONS; PLANETARY-NEBULA SYSTEM; DIFFUSE OPTICAL LIGHT; LUMINOSITY FUNCTION; INTEGRATED
Abstract We present a study of the stellar populations of globular clusters (GCs) in the Virgo Cluster core with a homogeneous spectroscopic catalog of 692 GCs within a major-axis distance R (maj) = 840 kpc from M87. We investigate radial and azimuthal variations in the mean age, total metallicity, [Fe/H], and alpha-element abundance of blue (metal-poor) and red (metal-rich) GCs using their co-added spectra. We find that the blue GCs have a steep radial gradient in [Z/H] within R (maj) = 165 kpc, with roughly equal contributions from [Fe/H] and [alpha/Fe], and flat gradients beyond. By contrast, the red GCs show a much shallower gradient in [Z/H], which is entirely driven by [Fe/H]. We use GC-tagged Illustris simulations to demonstrate an accretion scenario where more massive satellites (with more metal- and alpha-rich GCs) sink further into the central galaxy than less massive ones, and where the gradient flattening occurs because of the low GC occupation fraction of low-mass dwarfs disrupted at larger distances. The dense environment around M87 may also cause the steep [alpha/Fe] gradient of the blue GCs, mirroring what is seen in the dwarf galaxy population. The progenitors of red GCs have a narrower mass range than those of blue GCs, which makes their gradients shallower. We also explore spatial inhomogeneity in GC abundances, finding that the red GCs to the northwest of M87 are slightly more metal-rich. Future observations of GC stellar population gradients will be useful diagnostics of halo merger histories.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637X ISBN Medium
Area Expedition Conference
Notes WOS:000804426000001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1590
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Author (up) Liu, C.Z.; Cote, P.; Peng, E.W.; Roediger, J.; Zhang, H.X.; Ferrarese, L.; Sanchez-Janssen, R.; Guhathakurta, P.; Yang, X.H.; Jing, Y.P.; Alamo-Martinez, K.; Blakeslee, J.P.; Boselli, A.; Cuilandre, J.C.; Duc, P.A.; Durrell, P.; Gwyn, S.; Jordan, A.; Ko, Y.; Lancon, A.; Lim, S.; Longobardi, A.; Mei, S.; Mihos, J.C.; Munoz, R.; Powalka, M.; Puzia, T.; Spengler, C.; Toloba, E.
Title The Next Generation Virgo Cluster Survey. XXXIV. Ultracompact Dwarf Galaxies in the Virgo Cluster Type
Year 2020 Publication Astrophysical Journal Supplement Series Abbreviated Journal Astrophys. J. Suppl. Ser.
Volume 250 Issue 1 Pages 28 pp
Keywords Ultracompact dwarf galaxies; Globular star clusters; Galaxy nuclei; Dwarf elliptical galaxies; Virgo Cluster; Galaxy formation
Abstract We present a study of ultracompact dwarf (UCD) galaxies in the Virgo cluster based mainly on imaging from the Next Generation Virgo Cluster Survey (NGVS). Using similar to 100 deg(2) of u*giz imaging, we have identified more than 600 candidate UCDs, from the core of Virgo out to its virial radius. Candidates have been selected through a combination of magnitudes, ellipticities, colors, surface brightnesses, half-light radii, and, when available, radial velocities. Candidates were also visually validated from deep NGVS images. Subsamples of varying completeness and purity have been defined to explore the properties of UCDs and compare to those of globular clusters and the nuclei of dwarf galaxies with the aim of delineating the nature and origins of UCDs. From a surface density map, we find the UCDs to be mostly concentrated within Virgo's main subclusters, around its brightest galaxies. We identify several subsamples of UCDs-i.e., the brightest, largest, and those with the most pronounced and/or asymmetric envelopes-that could hold clues to the origin of UCDs and possible evolutionary links with dwarf nuclei. We find some evidence for such a connection from the existence of diffuse envelopes around some UCDs and comparisons of radial distributions of UCDs and nucleated galaxies within the cluster.
Address [Liu, Chengze; Yang, Xiaohu; Jing, Yipeng] Shanghai Jiao Tong Univ, Sch Phys & Astron, Dept Astron, Shanghai 200240, Peoples R China, Email: czliu@sjtu.edu.cn
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0067-0049 ISBN Medium
Area Expedition Conference
Notes WOS:000570603400001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1251
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Author (up) Vergara, C.; Munoz, R.; Campos, J.L.; Seeger, M.; Jeison, D.
Title Influence of light intensity on bacterial nitrifying activity in algal-bacterial photobioreactors and its implications for microalgae-based wastewater treatment Type
Year 2016 Publication International Biodeterioration & Biodegradation Abbreviated Journal Int. Biodeterior. Biodegrad.
Volume 114 Issue Pages 116-121
Keywords Nitrification; Ammonium oxidizer; Nitrite oxidizer; Microalgal-bacterial consortium; Photobioreactor; Photoinhibition; Wastewater treatment
Abstract The influence of irradiance on the nitrifying activity in photobioreactors of a bacterial consortium enriched from a wastewater treatment bioreactor was assessed using independent ammonium oxidation kinetic batch tests and respirometric assays. Culture irradiance below 250 μmol m(-2) s(-1) did not show a significant effect on nitrification activity, while irradiance at 500 and 1250 μmol m(-2) s(-1) caused a decrease of 20 and 60% in the specific total ammonium nitrogen removal rates and a reduction of 26 and 71% in the specific NO3- production rates, respectively. However, no significant influence of irradiance on the affinity constant of NH4+ oxidation was observed. The increasing nitrite accumulation at higher light intensities suggested a higher light sensitivity of nitrite oxidizers. Additionally, NH4+ oxidation respirometric assays showed a decrease in the oxygen uptake of 14 and 50% at 500 and 1250 μmol m(-2) s(-1), respectively. The experimental determination of the light extinction coefficient (lambda) of the nitrifying bacterial consortium (lambda = 0.0003 m(2) g(-1)) and of Chlorella sorokiniana (lambda = 0.1045 m(2) g(-1)) allowed the estimation of light penetration in algal-bacterial high rate algal ponds, which showed that photo inhibition of nitrifying bacteria can be significantly mitigated in the presence of high density microalgal cultures. 2016 Elsevier Ltd. All rights reserved.
Address [Vergara, C.; Jeison, D.] Univ La Frontera, Dept Chem Engn, Francisco Salazar 01145, Temuco, Chile, Email: christian.vergara@ufrontera.cl
Corporate Author Thesis
Publisher Elsevier Sci Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0964-8305 ISBN Medium
Area Expedition Conference
Notes WOS:000383528000016 Approved
Call Number UAI @ eduardo.moreno @ Serial 657
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