
Beltran, J. F., Nunez, E., Nunez, F., Silva, I., Bravo, T., & Moffat, R. (2018). Static response of asymmetrically damaged metallic strands: Experimental and numerical approach. Constr. Build. Mater., 192, 538–554.
Abstract: In this study, the effect of the presence of broken wires (damage) asymmetrically distributed on metallic strands surfaces on their static response is assessed. To this end, a general mechanical model for multi layered strands is presented, in which damaged strands are treated as a 1D nonlinear beam under uncoupled biaxial bending and axial load (NLBM). The NLBM is validated by comparisons with the results obtained from an experimental program especially designed for studying the effect of surface damage distribution on strands response and 3D nonlinear finite element simulations. Analyses are carried out on two strand constructions: 1 x 7 and 1 x 19, in which the damage levels and strand diameters vary from 5% to 40% and from 3.5 mm to 22.2 mm, respectively. Results indicate that the NLBM accurate predicts the static response (residual strength, stiffness, axial strain field, and deformed configuration) of the asymmetrically damaged strands, achieving good computational efficiency and numerical robustness. (C) 2018 Elsevier Ltd. All rights reserved.



Contreras, M., & Pena, J. P. (2019). The quantum dark side of the optimal control theory. Physica A, 515, 450–473.
Abstract: In a recent article, a generic optimal control problem was studied from a physicist's point of view (Contreras et al. 2017). Through this optic, the Pontryagin equations are equivalent to the Hamilton equations of a classical constrained system. By quantizing this constrained system, using the right ordering of the operators, the corresponding quantum dynamics given by the Schrodinger equation is equivalent to that given by the HamiltonJacobiBellman equation of Bellman's theory. The conclusion drawn there were based on certain analogies between the equations of motion of both theories. In this paper, a closer and more detailed examination of the quantization problem is carried out, by considering three possible quantization procedures: right quantization, left quantization, and Feynman's path integral approach. The Bellman theory turns out to be the classical limit h > 0 of these three different quantum theories. Also, the exact relation of the phase S(x, t) of the wave function Psi(x, t) = e(i/hS(x,t)) of the quantum theory with Bellman's cost function J(+)(x, t) is obtained. In fact, S(x, t) satisfies a 'conjugate' form of the HamiltonJacobiBellman equation, which implies that the cost functional J(+)(x, t) must necessarily satisfy the usual HamiltonJacobiBellman equation. Thus, the Bellman theory effectively corresponds to a quantum view of the optimal control problem. (C) 2018 Elsevier B.V. All rights reserved.



Jungles, M. K., Val del Rio, A., MosqueraCorral, A., Campos, J. L., Mendez, R., & Costa, R. H. R. (2017). Effects of Inoculum Type and Aeration Flowrate on the Performance of Aerobic Granular SBRs. Processes, 5(3), 10 pp.
Abstract: Aerobic granular sequencing batch reactors (SBRs) are usually inoculated with activated sludge which implies sometimes long startup periods and high solids concentrations in the effluent due to the initial washout of the inoculum. In this work, the use of aerobic mature granules as inoculum in order to improve the startup period was tested, but no clear differences were observed compared to a reactor inoculated with activated sludge. The effect of the aeration rate on both physical properties of granules and reactor performance was also studied in a stable aerobic granular SBR. The increase of the aeration flow rate caused the decrease of the average diameter of the granules. This fact enhanced the COD and ammonia consumption rates due to the increase of the DO level and the aerobic fraction of the biomass. However, it provoked a loss of the nitrogen removal efficiency due to the worsening of the denitrification capacity as a consequence of a higher aerobic fraction.



Ruz, G. A., Zuniga, A., & Goles, E. (2018). A Boolean network model of bacterial quorumsensing systems. Int. J. Data Min. Bioinform., 21(2), 123–144.
Abstract: There are several mathematical models to represent gene regulatory networks, one of the simplest is the Boolean network paradigm. In this paper, we reconstruct a regulatory network of bacterial quorumsensing systems, in particular, we consider Paraburkholderia phytofirmans PsJN which is a plant growth promoting bacteria that produces positive effects in horticultural crops like tomato, potato and grape. To learn the regulatory network from temporal expression pattern of quorumsensing genes at root plants, we present a methodology that considers the training of perceptrons for each gene and then the integration into one Boolean regulatory network. Using the proposed approach, we were able to infer a regulatory network model whose topology and dynamic exhibited was helpful to gain insight on the quorumsensing systems regulation mechanism. We compared our results with REVEAL and BestFit extension algorithm, showing that the proposed neural network approach obtained a more biologically meaningful network and dynamics, demonstrating the effectiveness of the proposed method.



Mora, F., Coullet, P., Rica, S., & Tirapegui, E. (2018). Numerical path integral calculation of the probability function and exit time: an application to nongradient drift forces. Philos. Trans. R. Soc. AMath. Phys. Eng. Sci., 376(2135), 11 pp.
Abstract: We provide numerical solutions based on the path integral representation of stochastic processes for nongradient drift Langevin forces in the presence of noise, to follow the temporal evolution of the probability density function and to compute exit times even for arbitrary noise. We compare the results with theoretical calculations, obtaining excellent agreement in the weak noise limit. This article is part of the theme issue 'Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)'.



Lobos, F., Goles, E., Ruivo, E. L. P., de Oliveira, P. P. B., & Montealegre, P. (2018). Mining a Class of Decision Problems for Onedimensional Cellular Automata. J. Cell. Autom., 13(56), 393–405.
Abstract: Cellular automata are locally defined, homogeneous dynamical systems, discrete in space, time and state variables. Within the context of onedimensional, binary, cellular automata operating on cyclic configurations of odd length, we consider the general decision problem: if the initial configuration satisfies a given property, the lattice should converge to the fixedpoint of all 1s ((1) over right arrow), or to (0) over right arrow, otherwise. Two problems in this category have been widely studied in the literature, the parity problem [1] and the density classification task [4]. We are interested in determining all cellular automata rules with neighborhood sizes of 2, 3, 4 and 5 cells (i.e., radius r of 0.5, 1, 1.5 and 2.5) that solve decision problems of the previous type. We have demonstrated a theorem that, for any given rule in those spaces, ensures the non existence of fixed points other than (0) over right arrow and (1) over right arrow for configurations of size larger than 2(2r), provided that the rule does not support different fixed points for any configuration with size smaller than or equal to 2(2r). In addition, we have a proposition that ensures the convergence to only (0) over right arrow or (1) over right arrow of any initial configuration, if the rule complies with given conditions. By means of theoretical and computational approaches, we determined that: for the rule spaces defined by radius 0.5 and r = 1, only 1 and 2 rules, respectively, converge to (1) over right arrow or (0) over right arrow, to any initial configuration, and both recognize the same language, and for the rule space defined by radius r = 1.5, 40 rules satisfy this condition and recognize 4 different languages. Finally, for the radius 2 space, out of the 4,294,967,296 different rules, we were able to significantly filter it out, down to 40,941 candidate rules. We hope such an extensive mining should unveil new decision problems of the type widely studied in the literature.



Bergen, M., & Munoz, F. D. (2018). Quantifying the effects of uncertain climate and environmental policies on investments and carbon emissions: A case study of Chile. Energy Econ., 75, 261–273.
Abstract: In this article we quantify the effect of uncertainty of climate and environmental policies on transmission and generation investments, as well as on CO2 emissions in Chile. We use a twostage stochastic planning model with recourse or corrective investment options to find optimal portfolios of infrastructure both under perfect information and uncertainty. Under a series of assumptions, this model is equivalent to the equilibrium of a much more complicated bilevel market model, where a transmission planner chooses investments first and generation firms invest afterwards. We find that optimal investment strategies present important differences depending on the policy scenario. By changing our assumption of how agents will react to this uncertainty we compute bounds on the cost that this uncertainty imposes on the system, which we estimate ranges between 3.2% and 5.7% of the minimum expected system cost of $57.6B depending on whether agents will consider or not uncertainty when choosing investments. We also find that, if agents choose investments using a stochastic planning model, uncertain climate policies can result in nearly 18% more CO2 emissions than the equilibrium levels observed under perfect information. Our results highlight the importance of credible and stable longterm regulations for investors in the electric power industry if the goal is to achieve climate and environmental targets in the most costeffective manner and to minimize the risk of asset stranding. (C) 2018 Elsevier B.V. All rights reserved.



Arriagada, R., Aldunce, P., Blanco, G., Ibarra, C., Moraga, P., Nahuelhual, L., et al. (2018). Climate change governance in the anthropocene: emergence of polycentrism in Chile. ElementaSci. Anthrop., 6, 13 pp.
Abstract: Multilateral efforts are essential to an effective response to climate change, but individual nations define climate action policy by translating local and global objectives into adaptation and mitigation actions. We propose a conceptual framework to explore opportunities for polycentric climate governance, understanding polycentricity as a property that encompasses the potential for coordinating multiple centers of semiautonomous decisionmaking. We assert that polycentrism engages a diverse array of public and private actors for a more effective approach to reducing the threat of climate change. In this way, polycentrism may provide an appropriate strategy for addressing the many challenges of climate governance in the Anthropocene. We review two Chilean case studies: Chile's Nationally Determined Contribution on Climate Change and the Chilean National Climate Change Action Plan. Our examination demonstrates that Chile has included a diversity of actors and directed significant financial resources to both processes. The central government coordinated both of these processes, showing the key role of interventions at higher jurisdictional levels in orienting institutional change to improve strategic planning and better address climate change. Both processes also provide some evidence of knowledge coproduction, while at the same time remaining primarily driven by state agencies and directed by technical experts. Efforts to overcome governance weaknesses should focus on further strengthening existing practices for climate change responses, establishing new institutions, and promoting decisionmaking that incorporates diverse social actors and multiple levels of governance. In particular, stronger inclusion of local level actors provides an opportunity to enhance polycentric modes of governance and improve climate change responses. Fully capitalizing on this opportunity requires establishing durable communication channels between different levels of governance.



MoraRuiz, M. D., AlejandreColomo, C., Ledger, T., Gonzalez, B., Orfila, A., & RosselloMora, R. (2018). Nonhalophilic endophytes associated with the euhalophyte Arthrocnemum macrostachyum and their plant growth promoting activity potential. FEMS Microbiol. Lett., 365(19), 11 pp.
Abstract: Numerous microbial taxa establish natural relations with plants, and especially endophytes can be relevant in the development and growth promotion of their host. In this work, we explore the diversity of nonhalophilic microorganisms inhabiting the endosphere of the halophyte Arthrocnemum macrostachyum. A total of 1045 isolates were recovered using standard nonsaline media, which clustered into 22 operational phylogenetic units (OPUs) including 7 putative new species and 13 OPUs not previously detected as endophytes. The more abundant isolates corresponded to close relatives of Kushneria indalinina/K. marisflavi, Providencia rettgeri, Pseudomonas zhaodongensis and Bacillus safensis, which made up to similar to 62% of the total isolates. We also isolated OPUs not detected by the cultureindependent approach reinforcing the need of culturing to reveal the microbial diversity associated with plants. Additionally, the plant growth promoting activity was evaluated by representative strains of the more abundant OPUs (total = 94 strains) including also some previously isolated halophiles from the same plants. Under both saline and nonsaline conditions, some strains principally those affiliated to Paenibacillus borealis, Staphylococcus equorum, Salinicola halophilus and Marinococcus tarijensis, presented growth promoting activity in Arabidopsis thaliana, which was evaluated as an increment of weight and root length.



Averbakh, I., & Pereira, J. (2018). Lateness Minimization in Pairwise Connectivity Restoration Problems. INFORMS J. Comput., 30(3), 522–538.
Abstract: A network is given whose edges need to be constructed (or restored after a disaster). The lengths of edges represent the required construction/restoration times given available resources, and one unit of length of the network can be constructed per unit of time. All points of the network are accessible for construction at any time. For each pair of vertices, a due date is given. It is required to find a construction schedule that minimizes the maximum lateness of all pairs of vertices, where the lateness of a pair is the difference between the time when the pair becomes connected by an already constructed path and the pair's due date. We introduce the problem and analyze its structural properties, present a mixedinteger linear programming formulation, develop a number of lower bounds that are integrated in a branchandbound algorithm, and discuss results of computational experiments both for instances based on randomly generated networks and for instances based on 2010 Chilean earthquake data.



Concha, P., Merino, N., Miskovic, O., Rodriguez, E., SalgadoRebolledo, P., & Valdivia, O. (2018). Asymptotic symmetries of threedimensional ChernSimons gravity for the Maxwell algebra. J. High Energy Phys., (10), 22 pp.
Abstract: We study a threedimensional ChernSimons gravity theory based on the Maxwell algebra. We find that the boundary dynamics is described by an enlargement and deformation of the bms(3) algebra with three independent central charges. This symmetry arises from a gravity action invariant under the local Maxwell group and is characterized by presence of Abelian generators which modify the commutation relations of the supertranslations in the standard bms(3) algebra. Our analysis is based on the charge algebra of the theory in the BMS gauge, which includes the known solutions of standard asymptotically flat case. The field content of the theory is different than the one of General Relativity, but it includes all its geometries as particular solutions. In this line, we also study the stationary solutions of the theory in ADM form and we show that the vacuum energy and the vacuum angular momentum of the stationary configuration are influenced by the presence of the gravitational Maxwell field.



Kristiansen, M., Munoz, F. D., Oren, S., & Korpas, M. (2018). A Mechanism for Allocating Benefits and Costs from Transmission Interconnections under Cooperation: A Case Study of the North Sea Offshore Grid. Energy J., 39(6), 209–234.
Abstract: We propose a generic mechanism for allocating the benefits and costs that result from the development of international transmission interconnections under a cooperative agreement. The mechanism is based on a planning model that considers generation investments as a response to transmission developments, and the Shapley Value from cooperative game theory. This method provides a unique allocation of benefits and costs considering each country's average incremental contribution to the cooperative agreement. The allocation satisfies an axiomatic definition of fairness. We demonstrate our results for three planned transmission interconnections in the North Sea and show that the proposed mechanism can be used as a basis for defining a set of Power Purchase Agreements among countries. This achieves the desired final distribution of economic benefits and costs from transmission interconnections as countries trade power over time. We also show that, in this case, the proposed allocation is stable.



Hojman, S. A., & Asenjo, F. A. (2018). Nongeodesic circular motion of massive spinning test bodies around a Schwarzschild field in the Lagrangian theory. Eur. Phys. J. C, 78(10), 7 pp.
Abstract: Recent interest on studying possible violations of the Equivalence Principle has led to the development of space satellite missions testing it for bodies moving on circular orbits around Earth. This experiment establishes that the validity of the equivalence principle is independent of the composition of bodies. However, the internal degrees of freedom of the bodies (such as spin) were not taken into account. In this work, it is shown exactly that the circular orbit motion of test bodies does present a departure from geodesic motion when spin effects are not negligible. Using a Lagrangian theory for spinning massive bodies, an exact solution for their circular motion is found showing that the nongeodesic behavior manifests through different tangential velocities of the test bodies, depending on the orientation of its spin with respect to the total angular momentum of the satellite. Besides, for circular orbits, spinning test bodies present no tangential acceleration. We estimate the difference of the two possible tangential velocities for the case of circular motion of spinning test bodies orbiting Earth.



Pietrobelli, C., Marin, A., & Olivari, J. (2018). Innovation in mining value chains: New evidence from Latin America. Resour. Policy, 58, 1–10.
Abstract: The paper investigates new opportunities for innovation and linkages associated to mining activities in Brazil, Chile and Peru. Three types of opportunities were researched: demand side, supply side and local specificities. The last source of opportunities is key for natural resource related activities. The evidence shows that an increasing demand is introducing important incentives for innovation and local suppliers. Nevertheless, a hierarchical value chain, dominated by few large firms, and poor linkages is blocking the diffusion of innovations and hindering suppliers' development. The emergence of a group of highly innovative suppliers, which were identified in the three countries, is explained mostly by new technological and knowledge opportunities, which are not exploited by large incumbents and open spaces for new entrants. Local specificities are also key in the explanation of local suppliers. It remains a challenge however, how these, most of which were created to satisfy local needs, will move from local to global.



Manzello, S. L., Blanchi, R., Gollner, M. J., Gorham, D., McAllister, S., Pastor, E., et al. (2018). Summary of workshop large outdoor fires and the built environment. Fire Saf. J., 100, 76–92.
Abstract: Large outdoor fires present a risk to the built environment. Wildfires that spread into communities, referred to as WildlandUrban Interface (WUI) fires, have destroyed communities throughout the world, and are an emerging problem in fire safety science. Other examples are large urban fires including those that have occurred after earthquakes. Research into large outdoor fires, and how to potentially mitigate the loss of structures in such fires, lags other areas of fire safety science research. At the same time, common characteristics between fire spread in WUI fires and urban fires have not been fully exploited. In this paper, an overview of the large outdoor fire risk to the built environment from each region is presented. Critical research needs for this problem in the context of fire safety science are provided. The present paper seeks to develop the foundation for an international research needs roadmap to reduce the risk of large outdoor fires to the built environment.



Garmendia, M. L., Matus, O., Mondschein, S., & Kusanovic, J. P. (2018). Gestational weight gain recommendations for Chilean women: a mathematical optimization approach. Public Health, 163, 80–86.
Abstract: Objectives: We examined if the guidelines for gestational weight gain (GWG) proposed by the Institute of Medicine (IOM) are the most suitable for Chilean women. Study design: Secondary analysis of records of single fullterm births at the Dr. Sotero del Rio Hospital, Santiago, Chile, during 20032012 (n = 62,579). Methods: From clinical records, we obtained data regarding maternal age, height, prepregnancy and at delivery weights, pathologies during pregnancy such as gestational diabetes (GDM) and preeclampsia, gestational age at delivery, and number of infants born small for gestational age (SGA) and large for gestational age (LGA). We formulated a mathematical model (MM) to determine the GWG range that maximizes the likelihood of a healthy pregnancy (HP) if the recommendation is followed. We defined an HP as one where the mother has no complications such as preeclampsia, GDM, SGA, or LGA. Results: Fortysix percent of women had prepregnancy overweight or obesity. The prevalence of GDM, preeclampsia, SGA, and LGA were 3%, 1.2%, 9%, and 12%, respectively. An HP was present in 76% of pregnancies, 79% in the underweight group, 79% in normal weight group, 74% in the overweight group, and 67% in obese women. The GWG recommendations given by the MM (1420 kg for underweight, 620 kg for normal weight, 9 11 kg for overweight, and 67 kg for obese) led to higher probabilities of achieving an HP than the ones obtained with the IOM recommendations. Conclusion: The adoption of GWG recommendations based on characteristics of the Chilean population might lead to better short and longterm health results for pregnant women. (C) 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.



Caroca, R., Concha, P., Fierro, O., Rodriguez, E., & SalgadoRebolledo, P. (2018). Generalized ChernSimons higherspin gravity theories in three dimensions. Nucl. Phys. B, 934, 240–264.
Abstract: The coupling of spin3 gauge fields to threedimensional Maxwell and AdSLorentz gravity theories is presented. After showing how the usual spin3 extensions of the Ad S and the Poincare algebras in three dimensions can be obtained as expansions of sl (3, R) algebra, the procedure is generalized so as to define new higherspin symmetries. Remarkably, the spin3 extension of the Maxwell symmetry allows one to introduce a novel gravity model coupled to higherspin topological matter with vanishing cosmological constant, which in turn corresponds to a flat limit of the AdSLorentz case. We extend our results to define two different families of higherspin extensions of threedimensional Einstein gravity. (C) 2018 The Authors. Published by Elsevier B.V.



Arevalo, I., Hernandez, R., Martin, M. J., & Vukotic, D. (2018). On weighted compositions preserving the Caratheodory class. Mon.heft. Math., 187(3), 459–477.
Abstract: We characterize in various ways the weighted composition transformations which preserve the class P of normalized analytic functions in the disk with positive real part. We analyze the meaning of the criteria obtained for various special cases of symbols and identify the fixed points of such transformations.



RomeroRomero, J. L., InostrozaBlancheteau, C., Orellana, D., Aquea, F., ReyesDiaz, M., Gil, P. M., et al. (2018). Stomata regulation by tissuespecific expression of the Citrus sinensis MYB61 transcription factor improves wateruse efficiency in Arabidopsis. Plant Physiol. Biochem., 130, 54–60.
Abstract: Wateruse efficiency (WUE) is a quantitative measurement of biomass produced per volume of water transpired by a plant. WUE is an important physiological trait for drought response to mitigate the water deficiency. In this work, a cisgenic construction from Citrus sinensis was developed and its function in the improvement of WUE was evaluated in Arabidopsis. Sequences of the CsMYB61 coding region, a transcription factor implicated in the closure of stomata, together with a putative stomataspecific promoter from CsMYB.1.5, were identified and cloned. The protein encoded in the CsMYB61 locus harbors domains and motifs characteristic of MYB61 proteins. In addition, a 1.2 kb promoter region of the gene CsMYB15 (pCsMYB15) containing regulatory elements for expression in guard cells and in response to Abscisic Acid (ABA) and light was isolated. In Arabidopsis, pCsMYB15 directs the expression of the reporter gene GUS in stomata in the presence of light. In addition, transgenic lines expressing the CsMYB61 coding region under transcriptional control of pCsMYB15 have a normal phenotype under in vitro and greenhouse conditions. These transgenic lines exhibited a smaller opening of the stomata pore, lower stomatal conductance and respiration rate, enhanced sensitivity to exogenous ABA, and high drought stress tolerance. Our results indicate that stomataspecific expression of CsMYB61 enhances water use efficiency under drought conditions in Arabidospis.



Carrasco, J. A., Harrison, R., & Villena, M. (2018). Interdependent preferences and endogenous reciprocity. J. Behav. Exp. Econ., 76, 68–75.
Abstract: This paper employs an indirect approach to formally examine the evolutionary stability of interdependent preferences when players randomly engage in pairwise interactions. Following the model specification for altruism and spitefulness in experiments proposed by Levine (1998), we also explore the stability of reciprocity and reciprocal preferences. In particular, we study how individuals equipped with intrinsic preferences such as altruism, selfishness or spitefulness adjust their behavior depending on who they interact with. The key aspect of our method is that behavioral preferences are choice variables that optimally evolve, accounting for strategic interaction. Our model predicts that in a specific economic framework characterized by negative externalities and strategic substitutes, there is a continuum of evolutionary stable interdependent preference profiles: At least one player behaves spitefully, and at most one acts selfishly. The emergence of altruism as an evolutionarily stable preference crucially depends on how large the support for preferences is. When players have reciprocal preferences, altruism might arise even in meetings where one player is intrinsically spiteful, but not necessarily from the intrinsically altruistic player.

