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Billi, M., Mascareno, A., Henriquez, P. A., Rodriguez, I., Padilla, F., & Ruz, G. A. (2022). Learning from crises? The long and winding road of the salmon industry in Chiloe Island, Chile. Mar. Pol., 140, 105069.
Abstract: The rapid development of salmon aquaculture worldwide and the growing criticism of the activity in recent decades have raised doubts about the capacity of the sector to learn from its own crises. In this article, we assess the discursive, behavioral and outcome performance dimensions of the industry to identify actual learning and lessons to be learned. We focus on the case of Chiloe Island, Chile, a global center of salmon production since 1990 that has gone through two severe crises in the last 15 years (2007-2009 ISAV crisis and 2016 red tide crisis). On the basis of a multi-method approach combining qualitative analysis of interviews and statistical data analysis, we observe that the industry has discursively learned the relevance of both self-regulation and the wellbeing of communities. However, at the behavioral and outcome performance levels, the data show a highly heterogeneous conduct that questions the ability of the sector as a whole to learn from crises. We conclude that detrimental effects for ecosystems and society will increase if learning remains at the level of discourses. Without significant changes in operational practices and market performance there are no real perspectives for the sustainability of the industry. This intensifies when considering the uneven responses to governance mechanisms. The sector needs to adapt its factual performance to sustainable goals and reflexively monitor this process. The first step for achieving this is to produce reliable data to make evidence-based decisions that align the operational dynamics of the entire sector with a more sustainable trajectory in the near future, as well as advancing towards hybrid and more reflexive governance arrangements.
Keywords: Crisis; Learning; Discourse; Behavior; Outcome performance; Aquaculture; Salmon industry; Governance; Regulation
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Canals, C., Goles, E., Mascareno, A., Rica, S., & Ruz, G. A. (2018). School Choice in a Market Environment: Individual versus Social Expectations. Complexity, 3793095, 11 pp.
Abstract: School choice is a key factor connecting personal preferences (beliefs, desires, and needs) and school offer in education markets. While it is assumed that preferences are highly individualistic forms of expectations by means of which parents select schools satisfying their internal moral standards, this paper argues that a better matching between parental preferences and school offer is achieved when individuals take into account their relevant network vicinity, thereby constructing social expectations regarding school choice. We develop two related models (individual expectations and social expectations) and prove that they are driven by a Lyapunov function, obtaining that both models converge to fixed points. Also, we assess their performance by conducting computational simulations. While the individual expectations model shows a probabilistic transition and a critical threshold below which preferences concentrate in a few schools and a significant amount of students is left unattended by the school offer, the social expectations model presents a smooth dynamics in which most of the schools have students all the time and no students are left out. We discuss our results considering key topics of the empirical research on school choice in educational market environments and conclude that social expectations contribute to improve information and lead to a better matching between school offer and parental preferences.
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Cordero, R., Mascareno, A., Henriquez, P. A., & Ruz, G. A. (2022). Drawing constitutional boundaries: A digital historical analysis of the writing process of Pinochet's 1980 authoritarian constitution. Hist. Methods, 55(3), 145–167.
Abstract: Drawing conceptual boundaries is one of the defining features of constitution-making processes. These historically situated operations of boundary making are central to the definition of what counts as “constitutional” in a political community. In this article, we study the operations of conceptual delimitation performed by the Constitutional Commission (1973-1978) that drafted the 1980 Chilean Constitution, the trademark of Augusto Pinochet's dictatorship. Using the eleven volumes of the Commission's Official Records as our textual material (10,915 pages and 80,005 distinct words), we apply vector semantics, spectral clustering and bigram graph-based analysis to explore conceptual boundaries and the behavior of specific keywords shaping the space of constitutional meanings. Our results identify the ways in which the Commission defines the normative horizon of the new social and political order by transforming old semantic references into a renewed conceptual framework. This analysis shows the immanent relations between political action and conceptual elaboration that underlie the creation of constitutional texts, as well as the potential of computational methods for the study of constitutional history and constitution-making processes.
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Goles, E., Mascareno, A., Medina, P., & Rica, S. (2020). Migration-induced transition in social structures: a view through the Sakoda model of social interactions. Sci. Rep., 10(1), 18338.
Abstract: We study the dynamics of three populations evolving in a two-dimensional discrete grid according to rules of attraction, rejection, or indifference following the framework of the seminal model by Sakoda and we apply it to migration phenomena. An interesting feature of the Sakoda model is the existence of a Potts-like energy which, as a common principle, decreases as time passes by. Here we consider the evolution of two populations until stabilization, then, we perturb this attractor by the inclusion of a third arrival: the immigrants. We show the conditions under which this irruption does not alter significantly the previous attractor (a sociological morphostatic behaviour) or it is dramatically changed (morphogenetic behaviour). We observe empirically that for a morphostatic behaviour the energy decreases while for morphogenesis this energy increases, revealing an escalation of social tension.
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Leleu, A., Alibert, Y., Hara, N. C., Hooton, M. J., Wilson, T. G., Robutel, P., et al. (2021). Six transiting planets and a chain of Laplace resonances in TOI-178. Astron. Astrophys., 649, A26.
Abstract: Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parent protoplanetary disc was still present. In this context, TOI-178 has been the subject of particular attention since the first TESS observations hinted at the possible presence of a near 2:3:3 resonant chain. Here we report the results of observations from CHEOPS, ESPRESSO, NGTS, and SPECULOOS with the aim of deciphering the peculiar orbital architecture of the system. We show that TOI-178 harbours at least six planets in the super-Earth to mini-Neptune regimes, with radii ranging from
1.152(-0.070)(+0.073)</textual-form> 1.152-0.070+0.073 to 2.87(-0.13)(+0.14)</textual-form> 2.87-0.13+0.14 Earth radii and periods of 1.91, 3.24, 6.56, 9.96, 15.23, and 20.71 days. All planets but the innermost one form a 2:4:6:9:12 chain of Laplace resonances, and the planetary densities show important variations from planet to planet, jumping from 1.02(-0.23)(+0.28)</textual-form> 1.02-0.23+0.28 to 0.177(-0.061)(+0.055)</textual-form> 0.177-0.061+0.055 times the Earth's density between planets c and d. Using Bayesian interior structure retrieval models, we show that the amount of gas in the planets does not vary in a monotonous way, contrary to what one would expect from simple formation and evolution models and unlike other known systems in a chain of Laplace resonances. The brightness of TOI-178 (H = 8.76 mag, J = 9.37 mag, V = 11.95 mag) allows for a precise characterisation of its orbital architecture as well as of the physical nature of the six presently known transiting planets it harbours. The peculiar orbital configuration and the diversity in average density among the planets in the system will enable the study of interior planetary structures and atmospheric evolution, providing important clues on the formation of super-Earths and mini-Neptunes. Keywords: HOT SUPER-EARTHS; TESS INPUT CATALOG; RADIUS DISTRIBUTION; MASS; SYSTEM; MODEL; STARS; MIGRATION; DYNAMICS; TOOL
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Mascareno, A., Cordero, R., Azocar, G., Billi, M., Henriquez, P. A., & Ruz, G. A. (2018). Controversies in social-ecological systems: lessons from a major red tide crisis on Chiloe Island, Chile. Ecol. Soc., 23(4), 25 pp.
Abstract: Connecting the discussions on resilience and governance of social-ecological systems (SESs) with the sociological analysis of social controversies, we explore a major red tide crisis on Chiloe Island, southern Chile, in 2016. Theoretically, we argue that controversies not only are methodological devices for the observation of the complex relations between nature and society in moments of crisis, but also are materially embedded in the SES dynamics and can work for or against systemic resilience. Empirically, we show that Chiloe's SES is an unstable regime prone to sudden shifts and identify the configuration of different lock-in mechanisms expressed in the reproduction of structural fragilities over the last three decades. From the examination of the social controversies on the 2016 red tide crisis, we draw several lessons. First, there is a complex interplay of visible and hidden fragilities of Chiloe's SES that, while being ignored or their resolution postponed to the future, materialize in the daily experience of inhabitants as a series of historical disappointments. Second, the unfolding of Chiloe's social-ecological crises involves epistemic disputes not only over concrete events but also on the very construction of the SES as a social-natural reality. In turn, this creates conditions for the emergence of strategic alignments between local, national, and transnational actors and shows the extent to which the socio-political articulation of knowledge may contribute to either improve or block the governance of the SES. Third, the social resources that came to light with the controversies reveal pathways for improving the governance regime of Chiloe Island's SES. This dimension highlights the normative relevance of commitments to recognize multiple scales of knowledge and articulate a plurality of actors in a nonhierarchical logic of cooperation.
Keywords: Chiloe Island; controversy; governance; regime shift; resilience; salmon aquaculture
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Mascareno, A., Goles, E., & Ruz, G. A. (2016). Crisis in complex social systems: A social theory view illustrated with the chilean case. Complexity, 21(S2), 13–23.
Abstract: The article argues that crises are a distinctive feature of complex social systems. A quest for connectivity of communication leads to increase systems' own robustness by constantly producing further connections. When some of these connections have been successful in recent operations, the system tends to reproduce the emergent pattern, thereby engaging in a non-reflexive, repetitive escalation of more of the same communication. This compulsive growth of systemic communication in crisis processes, or logic of excess, resembles the dynamic of self-organized criticality. Accordingly, we first construct the conceptual foundations of our approach. Second, we present three core assumptions related to the generative mechanism of social crises, their temporal transitions (incubation, contagion, restructuring), and the suitable modeling techniques to represent them. Third, we illustrate the conceptual approach with a percolation model of the crisis in Chilean education system. (c) 2016 Wiley Periodicals, Inc. Complexity 21: 13-23, 2016
Keywords: crisis; social complexity; social systems; communication; contagion
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Mascareno, A., Henriquez, P. A., Billi, M., & Ruz, G. A. (2020). A Twitter-Lived Red Tide Crisis on Chiloe Island, Chile: What Can Be Obtained for Social-Ecological Research through Social Media Analysis? Sustainability, 12(20), 38 pp.
Abstract: Considering traditional research on social-ecological crises, new social media analysis, particularly Twitter data, contributes with supplementary exploration techniques. In this article, we argue that a social media approach to social-ecological crises can offer an actor-centered meaningful perspective on social facts, a depiction of the general dynamics of meaning making that takes place among actors, and a systemic view of actors' communication before, during and after the crisis. On the basis of a multi-technique approach to Twitter data (TF-IDF, hierarchical clustering, egocentric networks and principal component analysis) applied to a red tide crisis on Chiloe Island, Chile, in 2016, the most significant red tide in South America ever, we offer a view on the boundaries and dynamics of meaning making in a social-ecological crisis. We conclude that this dynamics shows a permanent reflexive work on elucidating the causes and effects of the crisis that develops according to actors' commitments, the sequence of events, and political conveniences. In this vein, social media analysis does not replace good qualitative research, it rather opens up supplementary possibilities for capturing meanings from the past that cannot be retrieved otherwise. This is particularly relevant for studying social-ecological crises and supporting collective learning processes that point towards increased resilience capacities and more sustainable trajectories in affected communities.
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Rengifo, F., Ruz, G. A., & Mascareno, A. (2018). Managing the 1920s' Chilean educational crisis: A historical view combined with machine learning. PLoS One, 13(5), 23 pp.
Abstract: In the first decades of the 20 th century, political actors diagnosed the incubation of a crisis in the Chilean schooling process. Low rates of enrollment, literacy, and attendance, inefficiency in the use of resources, poverty, and a reduced number of schools were the main factors explaining the crisis. As a response, the Law on Compulsory Primary Education, considering mandatory for children between 6 and 14 years old to attend any school for at least four years, was passed in 1920. Using data from Censuses of the Republic of Chile from 1920 and 1930, reports of the Ministry of Justice, the Ministry of Education, and the Statistical Yearbooks between 1895 and 1930, we apply machine learning techniques (clustering and decision trees) to assess the impact of this law on the Chilean schooling process between 1920 and 1930. We conclude that the law had a positive impact on the schooling indicators in this period. Even though it did not overcome the differences between urban and rural zones, it brought about a general improvement of the schooling process and a more efficient use of resources and infrastructure in both big urban centers and small-urban and rural zones, thereby managing the so-called crisis of the Republic.
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Ruz, G. A., Henriquez, P. A., & Mascareno, A. (2020). Sentiment analysis of Twitter data during critical events through Bayesian networks classifiers. Futur. Gener. Comp. Syst., 106, 92–104.
Abstract: Sentiment analysis through machine learning using Twitter data has become a popular topic in recent years. Here we address the problem of sentiment analysis during critical events such as natural disasters or social movements. We consider Bayesian network classifiers to perform sentiment analysis on two datasets in Spanish: the 2010 Chilean earthquake and the 2017 Catalan independence referendum. In order to automatically control the number of edges that are supported by the training examples in the Bayesian network classifier, we adopt a Bayes factor approach for this purpose, yielding more realistic networks. The results show the effectiveness of using the Bayes factor measure as well as its competitive predictive results when compared to support vector machines and random forests, given a sufficient number of training examples. Also, the resulting networks allow to identify the relations amongst words, offering interesting qualitative information to historically and socially comprehend the main features of the event dynamics. (C) 2020 Elsevier B.V. All rights reserved.
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Ruz, G. A., Henriquez, P. A., & Mascareno, A. (2022). Bayesian Constitutionalization: Twitter Sentiment Analysis of the Chilean Constitutional Process through Bayesian Network Classifiers. Mathematics, 10(2), 166.
Abstract: Constitutional processes are a cornerstone of modern democracies. Whether revolutionary or institutionally organized, they establish the core values of social order and determine the institutional architecture that governs social life. Constitutional processes are themselves evolutionary practices of mutual learning in which actors, regardless of their initial political positions, continuously interact with each other, demonstrating differences and making alliances regarding different topics. In this article, we develop Tree Augmented Naive Bayes (TAN) classifiers to model the behavior of constituent agents. According to the nature of the constituent dynamics, weights are learned by the model from the data using an evolution strategy to obtain a good classification performance. For our analysis, we used the constituent agents' communications on Twitter during the installation period of the Constitutional Convention (July-October 2021). In order to differentiate political positions (left, center, right), we applied the developed algorithm to obtain the scores of 882 ballots cast in the first stage of the convention (4 July to 29 September 2021). Then, we used k-means to identify three clusters containing right-wing, center, and left-wing positions. Experimental results obtained using the three constructed datasets showed that using alternative weight values in the TAN construction procedure, inferred by an evolution strategy, yielded improvements in the classification accuracy measured in the test sets compared to the results of the TAN constructed with conditional mutual information, as well as other Bayesian network classifier construction approaches. Additionally, our results may help us to better understand political behavior in constitutional processes and to improve the accuracy of TAN classifiers applied to social, real-world data.
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