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Author Benitez, S.; Duarte, C.; Opitz, T.; Lagos, N.A.; Pulgar, J.M.; Vargas, C.A.; Lardies, M.A.
Title Intertidal pool fish Girella laevifrons (Kyphosidae) shown strong physiological homeostasis but shy personality: The cost of living in hypercapnic habitats Type
Year 2017 Publication Marine Pollution Bulletin Abbreviated Journal Mar. Pollut. Bull.
Volume 118 Issue 1-2 Pages 57-63
Keywords Carbon dioxide; Hypercapnic conditions; Physiology; Behavior; Intertidal pool; Fish
Abstract Tide pools habitats are naturally exposed to a high degree of environmental variability. The consequences of living in these extreme habitats are not well established. In particular, little it is known about of the effects of hypercanic seawater (i.e. high pCO(2) levels) on marine vertebrates such as intertidal pool fish. The aim of this study was to evaluate the effects of increased pCO(2) on the physiology and behavior in juveniles of the intertidal pool fish Girella laevifrons. Two nominal pCO(2) concentrations (400 and 1600 patm) were used. We found that exposure to hypercapnic conditions did not affect oxygen consumption and absorption efficiency. However, the lateralization and boldness behavior was significantly disrupted in high pCO(2) conditions. In general, a predator-risk cost of boldness is assumed, thus the increased occurrence of shy personality in juvenile fishes may result in a change in the balance of this biological interaction, with significant ecological consequences. (C) 2017 Elsevier Ltd. All rights reserved.
Address [Benitez, S.; Lagos, N. A.] Univ Santo Tomos, Fac Ciencias, Ctr Invest & Innovat Cambia Climat CiiCC, Santiago, Chile, Email: cristian.duarte@unab.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0025-326x ISBN Medium
Area Expedition Conference
Notes WOS:000402217300020 Approved
Call Number UAI @ eduardo.moreno @ Serial 737
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Author Cabrera, M.; Cordova-Lepe, F.; Gutierrez-Jara, J.P-; Vogt-Geisse, K.
Title An SIR-type epidemiological model that integrates social distancing as a dynamic law based on point prevalence and socio-behavioral factors Type
Year 2021 Publication Scientific Reports Abbreviated Journal Sci. Rep.
Volume 11 Issue 1 Pages 10170
Keywords EFFECTIVE REPRODUCTION NUMBER; INFECTIOUS-DISEASE; TRANSMISSION; COVID-19; BEHAVIOR; CHALLENGES; AWARENESS; IMPACT; RISK
Abstract Modeling human behavior within mathematical models of infectious diseases is a key component to understand and control disease spread. We present a mathematical compartmental model of Susceptible-Infectious-Removed to compare the infected curves given by four different functional forms describing the transmission rate. These depend on the distance that individuals keep on average to others in their daily lives. We assume that this distance varies according to the balance between two opposite thrives: the self-protecting reaction of individuals upon the presence of disease to increase social distancing and their necessity to return to a culturally dependent natural social distance that occurs in the absence of disease. We present simulations to compare results for different society types on point prevalence, the peak size of a first epidemic outbreak and the time of occurrence of that peak, for four different transmission rate functional forms and parameters of interest related to distancing behavior, such as: the reaction velocity of a society to change social distance during an epidemic. We observe the vulnerability to disease spread of close contact societies, and also show that certain social distancing behavior may provoke a small peak of a first epidemic outbreak, but at the expense of it occurring early after the epidemic onset, observing differences in this regard between society types. We also discuss the appearance of temporal oscillations of the four different transmission rates, their differences, and how this oscillatory behavior is impacted through social distancing; breaking the unimodality of the actives-curve produced by the classical SIR-model.
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 2045-2322 ISBN Medium
Area Expedition Conference
Notes WOS:000656941100009 Approved
Call Number UAI @ alexi.delcanto @ Serial 1417
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Author Deacon, R.M.J.; Hurley, M.J.; Rebolledo, C.M.; Snape, M.; Altimiras, F.J.; Farias, L.; Pino, M.; Biekofsky, R.; Glass, L.; Cogram, P.
Title Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566 Type
Year 2017 Publication Genes Brain And Behavior Abbreviated Journal Genes Brain Behav.
Volume 16 Issue 7 Pages 1-10
Keywords Autism spectrum disorder; behavior; E-cadherin; Fmr1 knockout mouse; fragile X syndrome; GST-alpha 1; NNZ2566; NQO1; Nrf2/ARE pathway; oxidative stress
Abstract Fragile X-associated disorders are a family of genetic conditions resulting from the partial or complete loss of fragile X mental retardation protein (FMRP). Among these disorders, fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and autism. Progress in basic neuroscience has led to identification of molecular targets for treatment in FXS; however, there is a gap in translation to targeted therapies in humans. This study introduces a novel therapeutic target for FXS, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a transcription factor known to induce expression of over 100 cytoprotective genes. We also show that NNZ2566, a drug that has successfully completed a phase 2 clinical trial in FXS, is effective in modulating this target in FXS, partially reversing the FXS phenotype; NNZ2566 has a therapeutic role as Nrf2 activator. Effectively, treatment with NNZ2566 normalizes the translocation of Nrf2 to the nucleus, inducing expression of numerous oxidative stress-related genes including NQO1 (NAD(P) H dehydrogenase quinone 1), GST-alpha 1 (glutathione S-transferase alpha-1) and EH (epoxide hydrolase) and has a knockdown effect on E-cadherin. In summary, the Nrf2/ARE (antioxidant response element) pathway appears to be a novel promising therapeutic target for FXS and NNZ2566 appears to be acting as an activator of the Nrf2/ARE pathway and suggests a potential benefit across multiple symptoms that could be associated with the pathobiological processes underlying FXS.
Address [Deacon, R. M. J.; Altimiras, F. J.; Farias, L.; Pino, M.; Cogram, P.] Fraunhofer Res Fdn, Biomed Div, Ctr Syst Biotechnol, Santiago, Chile, Email: robertmj.deacon@gmail.com;
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1601-1848 ISBN Medium
Area Expedition Conference
Notes WOS:000410314200008 Approved
Call Number UAI @ eduardo.moreno @ Serial 861
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Author Martinez, C.; Briones, F.; Rojas, P.; Aguilar, C.; Guzman, D.; Ordonez, S.
Title Microstructural and mechanical characterization of copper, nickel, and Cu-based alloys obtained by mechanical alloying and hot pressing Type
Year 2017 Publication Materials Letters Abbreviated Journal Mater. Lett.
Volume 209 Issue Pages 509-512
Keywords BULK METALLIC GLASSES; CORROSION BEHAVIOR; THERMAL-STABILITY; AMORPHOUS-ALLOYS; GRAIN-SIZE; NANOCRYSTALLINE; CRYSTALLINE; HEAT
Abstract Mechanical alloying and uniaxial compaction were used to obtain configurations of: elemental powders of Cu and Ni; binary alloys (Cu-Ni and Cu-Zr); and a ternary alloy (Cu-Ni-Zr) under the same mechanical milling and hot pressing conditions. Microstructure and mechanical properties of these were investigated. According to XRD results, hot pressing process increases crystallite size and decreases microstrain in the compact samples, due to the release of crystalline defects without crystallization of amorphous alloys. The milled powder samples have a higher hardness than the unmilled samples, since crystal defects are incorporated into microstructural refinement during milling. The ternary alloy Cu-40Ni-10Zr had the highest hardness of all systems studied, reaching 689 HV0.5. Compression tests at 5% strain determined that Zr-containing samples (amorphous phase) become more fragile after processing, and have the lowest values of compressive strength. In contrast, Ni samples and Cu-Ni binary alloys are more resistant to compression. (
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 0167-577X ISBN Medium
Area Expedition Conference
Notes WOS:000413124300129 Approved
Call Number UAI @ alexi.delcanto @ Serial 1409
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Author Martinez, C.; Briones, F.; Rojas, P.; Ordonez, S.; Aguilar, C.; Guzman, D.
Title Microstructure and Mechanical Properties of Copper, Nickel and Ternary Alloys Cu-Ni-Zr Obtained by Mechanical Alloying and Hot Pressing Type
Year 2017 Publication MRS Advances Abbreviated Journal MRS Adv.
Volume 2 Issue 50 Pages 2831-2836
Keywords BULK METALLIC GLASSES; GRAIN-SIZE; NANOCRYSTALLINE MATERIALS; AMORPHOUS-ALLOYS; PROFILE ANALYSIS; BEHAVIOR; POWDERS; WEAR
Abstract Elemental powders of Cu and Ni, binary alloys (Cu-Ni and Cu-Zr) and ternary alloy (Cu-Ni-Zr) obtained by mechanical alloying and uniaxial compaction hot microstructure and mechanical properties were investigated. The alloys studied were: pure Cu, pure Ni, binary alloys (Cu-Ni; Cu-Zr) and ternary alloys (Cu-Ni-Zr) under the same mechanical milling and hot pressing conditions. The samples were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM); the mechanical properties were studied by compression tests and hardness in Vickers scale (HV0.5) on polished surfaces at room temperature. According to XRD results, hot pressing process crystallite size increase and microstrain decreases in the compact samples due to the release of crystalline defects. The compacted samples have porosity of approximately 20%. The milling powder samples have a higher hardness than the unmilled samples, this because during milling crystal defects are incorporated together with the microstructural refinement. Ternary alloy is the one with the highest hardness of all systems studied, reaching 689 HV0.5. In compression tests determined a strain 5 %, Zr-containing samples become more fragile presenting the lowest values of compressive strength. In contrast, samples of Ni and Cu-Ni binary alloy are more resistant to compression.
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 2059-8521 ISBN Medium
Area Expedition Conference
Notes WOS:000412784800004 Approved
Call Number UAI @ alexi.delcanto @ Serial 1410
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Author Montalva-Medel, M.; Ledger, T.; Ruz, G.A.; Goles, E.
Title Lac Operon Boolean Models: Dynamical Robustness and Alternative Improvements Type
Year 2021 Publication Mathematics Abbreviated Journal Mathematics
Volume 9 Issue 6 Pages 600
Keywords ELEMENTARY CELLULAR-AUTOMATA; CARBON CATABOLITE REPRESSION; GLUCOSE-LACTOSE DIAUXIE; ESCHERICHIA-COLI; BLOCK INVARIANCE; MAXIMUM SENSITIVITY; BETA-GALACTOSIDASE; BISTABLE BEHAVIOR; BISTABILITY; NETWORK
Abstract In Veliz-Cuba and Stigler 2011, Boolean models were proposed for the lac operon in Escherichia coli capable of reproducing the operon being OFF, ON and bistable for three (low, medium and high) and two (low and high) parameters, representing the concentration ranges of lactose and glucose, respectively. Of these 6 possible combinations of parameters, 5 produce results that match with the biological experiments of Ozbudak et al., 2004. In the remaining one, the models predict the operon being OFF while biological experiments show a bistable behavior. In this paper, we first explore the robustness of two such models in the sense of how much its attractors change against any deterministic update schedule. We prove mathematically that, in cases where there is no bistability, all the dynamics in both models lack limit cycles while, when bistability appears, one model presents 30% of its dynamics with limit cycles while the other only 23%. Secondly, we propose two alternative improvements consisting of biologically supported modifications; one in which both models match with Ozbudak et al., 2004 in all 6 combinations of parameters and, the other one, where we increase the number of parameters to 9, matching in all these cases with the biological experiments of Ozbudak et al., 2004.
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 ISBN Medium
Area Expedition Conference
Notes WOS:000645324300001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1374
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Author Rojas, P.A .; Martinez, C.; Aguilar, C.; Briones, F.; Zelaya, M.E.; Guzman, D.
Title Characterization of phase changes during fabrication of copper alloys, crystalline and non-crystalline, prepared by mechanical alloying Type
Year 2016 Publication Ingenieria E Investigacion Abbreviated Journal Ing. Invest.
Volume 36 Issue 3 Pages 102-109
Keywords EXTENDED SOLID SOLUBILITY; CU-ZR BINARY; NANOCRYSTALLINE METALS; BEHAVIOR; POWDERS; SYSTEM; DISPERSION; GLASS; SIZE; TI
Abstract The manufacture of alloys in solid state has many differences with the conventional melting (casting) process. In the case of high energy milling or mechanical alloying, phase transformations of the raw materials are promoted by a large amount of energy that is introduced by impact with the grinding medium; there is no melting, but the microstructural changes go from microstructural refinement to amorphization in solid state. This work studies the behavior of pure metals (Cu and Ni), and different binary alloys (Cu-Ni and Cu-Zr), under the same milling/mechanical alloying conditions. After high-energy milling, X ray diffraction (XRD) patterns were analyzed to determine changes in the lattice parameter and find both microstrain and crystallite sizes, which were first calculated using the Williamson-Hall (W-H) method and then compared with the transmission electron microscope (TEM) images. Calculations showed a relatively appropriate approach to observations with TEM; however, in general, TEM observations detect heterogeneities, which are not considered for the W-H method. As for results, in the set of pure metals, we show that pure nickel undergoes more microstrain deformations, and is more abrasive than copper (and copper alloys). In binary systems, there was a complete solid solution in the Cu-Ni system and a glass-forming ability for the Cu-Zr, as a function of the Zr content. Mathematical methods cannot be applied when the systems have amorphization because there are no equations representing this process during milling. A general conclusion suggests that, under the same milling conditions, results are very different due to the significant impact of the composition: nickel easily forms a solid solution, while with a higher zirconium content there is a higher degree of glass-forming ability.
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 0120-5609 ISBN Medium
Area Expedition Conference
Notes WOS:000392963200014 Approved
Call Number UAI @ alexi.delcanto @ Serial 1411
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Author Villena, M.J.; Reus, L.
Title On the strategic behavior of large investors: A mean-variance portfolio approach Type
Year 2016 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 254 Issue 2 Pages 679-688
Keywords Investment analysis; Large investors; Strategic behavior; Markowitz portfolio allocation; Nash equilibrium
Abstract One key assumption of Markowitz's model is that all traders act as price takers. In this paper, we extend this mean-variance approach in a setting where large investors can move prices. Instead of having an individual optimization problem, we find the investors' Nash equilibrium and redefine the efficient frontier in this new framework. We also develop a simplified application of the general model, with two assets and two investors to shed light on the potential strategic behavior of large and atomic investors. Our findings validate the claim that large investors enhance their portfolio performance in relation to perfect market conditions. Besides, we show under which conditions atomic investors can benefit in relation to the standard setting, even if they have not total influence on their eventual performance. The 'two investors-two assets' setting allows us to quantify performance and do sensitivity analysis regarding investors' market power, risk tolerance and price elasticity of demand. Finally, for a group of well known ETFs, we empirically show how price variations change depending on the volume traded. We also explain how to set up and use our model with real market data. (C) 2016 Elsevier B.V. All rights reserved.
Address [Villena, Marcelo J.; Reus, Lorenzo] Univ Adolfo Ibanez, Fac Sci & Engn, Diagonal Torres 2640, Santiago, Chile, Email: marcelo.villena@uai.cl;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000377732300026 Approved
Call Number UAI @ eduardo.moreno @ Serial 627
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