
Burgers, T. A., Vivanco, J. F., Zahatnansky, J., Moren, A. J. V., Mason, J. J., & Williams, B. O. (2016). Mice with a heterozygous Lrp6 deletion have impaired fracture healing. Bone Res., 4, 9 pp.
Abstract: Bone fracture nonunions, the failure of a fracture to heal, occur in 10%20% of fractures and are a costly and debilitating clinical problem. The Wnt/betacatenin pathway is critical in bone development and fracture healing. Polymorphisms of linking lowdensity lipoprotein receptorrelated protein 6 (LRP6), a Wntbinding receptor, have been associated with decreased bone mineral density and fragility fractures, although this remains controversial. Mice with a homozygous deletion of Lrp6 have severe skeletal abnormalities and are not viable, whereas mice with a heterozygous deletion have a combinatory effect with Lrp5 to decrease bone mineral density. As fracture healing closely models embryonic skeletal development, we investigated the process of fracture healing in mice heterozygous for Lrp6 (Lrp6(+/)) and hypothesized that the heterozygous deletion of Lrp6 would impair fracture healing. Middiaphyseal femur fractures were induced in Lrp6(+/) mice and wildtype controls (Lrp6(+/+)). Fractures were analyzed using microcomputed tomography (mu CT) scans, biomechanical testing, and histological analysis. Lrp6(+/) mice had significantly decreased stiffness and strength at 28 days post fracture (PF) and significantly decreased BV/TV, total density, immature bone density, and mature area within the callus on day14 and 21 PF; they had significantly increased empty callus area at days 14 and 21 PF. Our results demonstrate that the heterozygous deletion of Lrp6 impairs fracture healing, which suggests that Lrp6 has a role in fracture healing.



Bustamante, M., & Contreras, M. (2016). Multiasset BlackScholes model as a variable second class constrained dynamical system. Physica A, 457, 540–572.
Abstract: In this paper, we study the multiasset BlackScholes model from a structural point of view. For this, we interpret the multiasset BlackScholes equation as a multidimensional Schrodinger one particle equation. The analysis of the classical Hamiltonian and Lagrangian mechanics associated with this quantum model implies that, in this system, the canonical momentums cannot always be written in terms of the velocities. This feature is a typical characteristic of the constrained system that appears in the highenergy physics. To study this model in the proper form, one must apply Dirac's method for constrained systems. The results of the Dirac's analysis indicate that in the correlation parameters space of the multi assets model, there exists a surface (called the Kummer surface Sigma(K), where the determinant of the correlation matrix is null) on which the constraint number can vary. We study in detail the cases with N = 2 and N = 3 assets. For these cases, we calculate the propagator of the multiasset BlackScholes equation and show that inside the Kummer Sigma(K) surface the propagator is well defined, but outside Sigma(K) the propagator diverges and the option price is not well defined. On Sigma(K) the propagator is obtained as a constrained path integral and their form depends on which region of the Kummer surface the correlation parameters lie. Thus, the multiasset BlackScholes model is an example of a variable constrained dynamical system, and it is a new and beautiful property that had not been previously observed. (C) 2016 Elsevier B.V. All rights reserved.



Bustamante, M., & Lefranc, G. (2011). Degradation Model Of Breast Imaging By Dispersed Radiation. Proc. Rom. Acad. Ser. AMath. Phys., 12(4), 347–352.
Abstract: This paper presents a model of interaction of radiation on breast, based on Bosso's filter. This model is used to improve mammographic images for early cancer diagnosis, to be more accurate and to detect cluster of microcalcifications. The model is based on degradation of breast image produced by dispersed radiation using the Bosso's filter, developed earlier.



Bustos, C., GarciaHerrera, C., Celentano, D., Chen, D., & Cruchaga, M. (2016). Numerical Simulation and Experimental Validation of the Inflation Test of Latex Balloons. Latin American Journal of Solids and Structures, 13, 2357–2378.
Abstract: Experiments and modeling aimed at assessing the mechanical response of latex balloons in the inflation test are presented. To this end, the hyperelastic Yeoh material model is firstly character ized via tensile test and, then, used to numerically simulate via finite elements the stressstrain evolution during the inflation test. The numerical pressuredisplacement curves are validated with those obtained experimentally. Moreover, this analysis is extended to a biomedical problem of an eyeball under glaucoma conditions.



Caceres, G., Anrique, N., Girard, A., Degreve, J., Baeyens, J., & Zhang, H. L. (2013). Performance of molten salt solar power towers in Chile. J. Renew. Sustain. Energy, 5(5), 15 pp.
Abstract: Chile is facing important challenges to develop its energy sector. Estimations demonstrate that in its electricity consumption Chile will grow at an annual rate of 4.6% until 2030, despite ongoing efficiency improvements. To satisfy this demand in a sustainable way, the national energy policy promotes the integration of novel and clean power generation into the national power mix, with special emphasis on concentrated solar power (CSP). The present paper assesses the development of solarbased electricity generation in Chile by CSP, achieved by a Solar Power Tower plant (SPT) using molten salt as heat carrier and store. Such SPTs can be installed at different locations in Chile, and connected to the main national grid. Results show that each SPT plant can generate around 76 GWh(el) of net electricity, when considering solar irradiation as the sole energy source and at a 16% overall efficiency of the SPT process. For operation in a continuous mode, a hybrid configuration with integrated gas backup system increases the generating potential of each SPT to 135 GWh(el). A preliminary Levelized Energy Cost (LEC) calculation provides LEC values between 0.15 and 0.18 $/kWh, as function of the overall process efficiency and estimated investment cost. Chile's solar irradiation favors the implementation of SPT plants. (C) 2013 AIP Publishing LLC.



Caceres, G., Montane, M., Nasirov, S., & O'Ryan, R. (2016). Review of Thermal Materials for CSP Plants and LCOE Evaluation for Performance Improvement using Chilean Strategic Minerals: Lithium Salts and Copper Foams. Sustainability, 8(2), 20 pp.



Caceres, G., Nasirov, S., Zhang, H. L., & ArayaLetelier, G. (2015). Residential Solar PV Planning in Santiago, Chile: Incorporating the PM10 Parameter. Sustainability, 7(1), 422–440.
Abstract: This paper addresses an economic study of the installation of photovoltaic (PV) solar panels for residential power generation in Santiago, Chile, based on the different parameters of a PV system, such as efficiency. As a performance indicator, the Levelized Cost of Energy (LCOE) was used, which indicates the benefit of the facility vs. the current cost of electrical energy. In addition, due to a high level of airborne dusts typically associated with PM10, the effect of the dust deposition on PV panels' surfaces and the effect on panel performance are examined. Two different scenarios are analyzed: ongrid PV plants and offgrid PV plants.



Campas, O., Rojas, E., Dumais, J., & Mahadevan, L. (2012). Strategies For Cell Shape Control In TipGrowing Cells. Am. J. Bot., 99(9), 1577–1582.
Abstract: Premise of the study: Despite the large diversity in biological cell morphology, the processes that specify and control cell shape are not yet fully understood. Here we study the shape of tipgrowing, walled cells, which have evolved a polar mode of cell morphogenesis leading to characteristic filamentous cell morphologies that extend only apically. Methods: We identified the relevant parameters for the control of cell shape and derived scaling laws based on mass conservation and force balance that connect these parameters to the resulting geometrical phenotypes. These laws provide quantitative testable relations linking morphological phenotypes to the biophysical processes involved in establishing and modulating cell shape in tipgrowing, walled cells. Key results and conclusions: By comparing our theoretical results to the observed morphological variation within and across species, we found that tipgrowing cells from plant and fungal species share a common strategy to shape the cell, whereas oomycete species have evolved a different mechanism.



Campos, J. L., del Rio, A. V., Pedrouso, A., Raux, P., Giustinianovich, E. A., & MosqueraCorral, A. (2017). Granular biomass floatation: A simple kinetic/stoichiometric explanation. Chem. Eng. J., 311, 63–71.
Abstract: Floatation events are commonly observed in anammox, denitrifying and anaerobic granular systems mostly subjected to overloading conditions. Although several operational strategies have been proposed to avoid floatation of granular biomass, until now, there is no consensus about the conditions responsible for this phenomenon. In the present study, a simple explanation based on kinetic and stoichiometric principles defining the aforementioned processes is provided. The operational zones corresponding to evaluated parameters where risk of floatation exists are defined as a function of substrate concentration in the bulk liquid and the radius of the granule. Moreover, the possible control of biomass floatation by changing the operating temperature was analyzed. Defined operational zones and profiles fit data reported in literature for granular biomass floatation events. From the study the most influencing parameter on floatation occurrence has been identified as the substrate concentration in the bulk media. (C) 2016 Elsevier B.V. All rights reserved.



Campos, J. L., ValenzuelaHeredia, D., Pedrouso, A., del Rio, A. V., Belmonte, M., & MosqueraCorral, A. (2016). Greenhouse Gases Emissions from Wastewater Treatment Plants: Minimization, Treatment, and Prevention. J. Chem., 3796352, 12 pp.
Abstract: The operation of wastewater treatment plants results in direct emissions, from the biological processes, of greenhouse gases (GHG) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2 O), as well as indirect emissions resulting from energy generation. In this study, three possible ways to reduce these emissions are discussed and analyzed: (1) minimization through the change of operational conditions, (2) treatment of the gaseous streams, and (3) prevention by applying new configurations and processes to remove both organic matter and pollutants. In current WWTPs, to modify the operational conditions of existing units reveals itself as possibly the most economical way to decrease N2 O and CO2 emissions without deterioration of effluent quality. Nowadays the treatment of the gaseous streams containing the GHG seems to be a not suitable option due to the high capital costs of systems involved to capture and clean them. The change of WWTP configuration by using microalgae or partial nitritationAnammox processes to remove ammonia from wastewater, instead of conventional nitrificationdenitrification processes, can significantly reduce the GHG emissions and the energy consumed. However, the area required in the case of microalgae systems and the current lack of information about stability of partial nitritationAnammox processes operating in the main stream of the WWTP are factors to be considered.



Canessa, E., & Chaigneau, S. (2014). The dynamics of social agreement according to Conceptual Agreement Theory. Qual. Quant., 48(6), 3289–3309.
Abstract: Many social phenomena can be viewed as processes in which individuals in social groups develop agreement (e.g., public opinion, the spreading of rumor, the formation of social and linguistic conventions). Conceptual Agreement Theory (CAT) models social agreement as a simplified communicational event in which an Observer and Actor exchange ideas about a concept , and where uses that information to infer whether 's conceptual state is the same as its own (i.e., to infer agreement). Agreement may be true (when infers that is thinking and this is in fact the case, event ) or illusory (when infers that is thinking and this is not the case, event ). In CAT, concepts that afford or become more salient in the minds of members of social groups. Results from an agentbased model (ABM) and probabilistic model that implement CAT show that, as our conceptual analyses suggested would be the case, the simulated social system selects concepts according to their usefulness to agents in promoting agreement among them (Experiment 1). Furthermore, the ABM exhibits more complex dynamics where similar minded agents cluster and are able to retain useful concepts even when a different group of agents discards them (Experiment 2). We discuss the relevance of CAT and the current findings for analyzing different social communication events, and suggest ways in which CAT could be put to empirical test.



Canessa, E., & Chaigneau, S. (2015). Calibrating AgentBased Models Using a Genetic Algorithm. Stud. Inform. Control, 24(1), 79–90.
Abstract: We present a Genetic Algorithm (GA)based tool that calibrates Agentbased Models (ABMs). The GA searches through a userdefined set of input parameters of an ABM, delivering values for those parameters so that the output time series of an ABM may match the real system's time series to certain precision. Once that set of possible values has been available, then a domain expert can select among them, the ones that better make sense from a practical point of view and match the explanation of the phenomenon under study. In developing the GA, we have had three main goals in mind. First, the GA should be easily used by nonexpert computer users and allow the seamless integration of the GA with different ABMs. Secondly, the GA should achieve a relatively short convergence time, so that it may be practical to apply it to many situations, even if the corresponding ABMs exhibit complex dynamics. Thirdly, the GA should use a few data points of the real system's time series and even so, achieve a sufficiently good match with the ABM's time series to attaining relational equivalence between the real system under study and the ABM that models it. That feature is important since social science longitudinal studies commonly use few data points. The results show that all of those goals have been accomplished.



Canessa, E., & Chaigneau, S. (2017). Response surface methodology for estimating missing values in a pareto genetic algorithm used in parameter design. Ing. Invest., 37(2), 89–98.
Abstract: We present an improved Pareto Genetic Algorithm (PGA), which finds solutions to problems of robust design in multiresponse systems with 4 responses and as many as 10 control and 5 noise factors. Because some response values might not have been obtained in the robust design experiment and are needed in the search process, the PGA uses Response Surface Methodology (RSM) to estimate them. Not only the PGA delivered solutions that adequately adjusted the response means to their target values, and with low variability, but also found more Pareto efficient solutions than a previous version of the PGA. This improvement makes it easier to find solutions that meet the tradeoff among variance reduction, mean adjustment and economic considerations. Furthermore, RSM allows estimating outputs' means and variances in highly nonlinear systems, making the new PGA appropriate for such systems.



Canessa, E., & Riolo, R. L. (2006). An agentbased model of the impact of computermediated communication on organizational culture and performance: an example of the application of complex systems analysis tools to the study of CIS. J. Inf. Technol., 21(4), 272–283.
Abstract: Organizations that make use of computer information systems (CIS) are prototypical complex adaptive systems (CAS). This paper shows how an approach from Complexity Science, exploratory agentbased modeling (ABM), can be used to study the impact of two different modes of use of computermediated communication (CMC) on organizational culture (OC) and performance. The ABM includes stylized representations of (a) agents communicating with other agents to complete tasks; (b) an OC consisting of the distribution of agent traits, changing as agents communicate; (c) the effect of OC on communication effectiveness (CE), and (d) the effect of CE on task completion times, that is, performance. If CMC is used in a broad mode, that is, to contact and collaborate with many, new agents, the development of a strong OC is slowed, leading to decreased CE and poorer performance early on. If CMC is used in a local mode, repeatedly contacting the same agents, a strong OC develops rapidly, leading to increased CE and high performance early on. However, if CMC is used in a broad mode over longer time periods, a strong OC can develop over a wider set of agents, leading to an OC that is stronger than an OC which develops with local CMC use. Thus broad use of CMC results in overall CE and performance that is higher than is generated by local use of CMC. We also discuss how the dynamics generated by an ABM can lead to a deeper understanding of the behavior of a CAS, for example, allowing us to better design empirical longitudinal studies.



Canessa, E., Droop, C., & Allende, H. (2012). An improved genetic algorithm for robust design in multivariate systems. Qual. Quant., 46(2), 665–678.
Abstract: In a previous article, we presented a genetic algorithm (GA), which finds solutions to problems of robust design in multivariate systems. Based on that GA, we developed a new GA that uses a new desirability function, based on the aggregation of the observed variance of the responses and the squared deviation between the mean of each response and its corresponding target value. Additionally, we also changed the crossover operator from a onepoint to a uniform one. We used three different case studies to evaluate the performance of the new GA and also to compare it with the original one. The first case study involved using data from a univariate real system, and the other two employed data obtained from multivariate process simulators. In each of the case studies, the new GA delivered good solutions, which simultaneously adjusted the mean of each response to its corresponding target value. This performance was similar to the one of the original GA. Regarding variability reduction, the new GA worked much better than the original one. In all the case studies, the new GA delivered solutions that simultaneously decreased the standard deviation of each response to almost the minimum possible value. Thus, we conclude that the new GA performs better than the original one, especially regarding variance reduction, which was the main problem exhibited by the original GA.



Canessa, E., Vera, S., & Allende, H. (2012). A new method for estimating missing values for a genetic algorithm used in robust design. Eng. Optimiz., 44(7), 787–800.
Abstract: This article presents an improved genetic algorithm (GA), which finds solutions to problems of robust design in multivariate systems with many control and noise factors. Since some values of responses of the system might not have been obtained from the robust design experiment, but may be needed in the search process, the GA uses response surface methodology (RSM) to estimate those values. In all test cases, the GA delivered solutions that adequately adjusted the mean of the responses to their corresponding target values and with low variability. The GA found more solutions than the previous versions of the GA, which makes it easier to find a solution that may meet the tradeoff among variance reduction, mean adjustment and economic considerations. Moreover, RSM is a good method for estimating the mean and variance of the outputs of highly nonlinear systems, which makes the new GA appropriate for optimizing such systems.



Canessa, E. C., & Chaigneau, S. E. (2016). When are concepts comparable across minds? Qual. Quant., 50(3), 1367–1384.
Abstract: In communication, people cannot resort to direct reference (e.g., pointing) when using diffuse concepts like democracy. Given that concepts reside in individuals' minds, how can people share those concepts? We argue that concepts are comparable across a social group if they afford agreement for those who use it; and that agreement occurs whenever individuals receive evidence that others conceptualize a given situation similarly to them. Based on Conceptual Agreement Theory, we show how to compute an agreement probability based on the sets of properties belonging to concepts. If that probability is sufficiently high, this shows that concepts afford an adequate level of agreement, and one may say that concepts are comparable across individuals' minds. In contrast to other approaches, our method considers that interindividual variability in naturally occurring conceptual content exists and is a fact that must be taken into account, whereas other theories treat variability as error that should be cancelled out. Given that conceptual variability will exist, our approach may establish whether concepts are comparable across individuals' minds more soundly than previous methods.



Canfora, F., Gomez, A., Sorella, S. P., & Vercauteren, D. (2014). Study of YangMills.ChernSimons theory in presence of the Gribov horizon. Ann. Phys., 345, 166–177.
Abstract: The twopoint gauge correlation function in YangMillsChernSimons theory in three dimensional Euclidean space is analysed by taking into account the nonperturbative effects of the Gribov horizon. In this way, we are able to describe the confinement and deconfinement regimes, which naturally depend on the topological mass and on the gauge coupling constant of the theory. (C) 2014 Elsevier Inc. All rights reserved.



Canfora, F. E., Dudal, D., Justo, I. F., Pais, P., SalgadoRebolledo, P., Rosa, L., et al. (2017). Double nonperturbative gluon exchange: An update on the softPomeron contribution to pp scattering. Phys. Rev. C, 96(2), 8 pp.
Abstract: We employ a set of recent, theoretically motivated fits to nonperturbative unquenched gluon propagators to check on how far double gluon exchange can be used to describe the soft sector of pp scattering data (total and differential cross section). In particular, we use the refined GribovZwanziger gluon propagator (as arising from dealing with the Gribov gauge fixing ambiguity) and the massive Cornwalltype gluon propagator (as motivated from DysonSchwinger equations) in conjunction with a perturbative quarkgluon vertex, next to a model based on the nonperturbative quarkgluon MarisTandy vertex, popular from BetheSalpeter descriptions of hadronic bound states. We compare the cross sections arising from these models with older ISR and more recent TOTEM and ATLAS data. The lower the value of total energy root s, the better the results appear to be.



Caniupan, M., Bravo, L., & Hurtado, C. A. (2012). Repairing inconsistent dimensions in data warehouses. Data Knowl. Eng., 7980, 17–39.
Abstract: A dimension in a data warehouse (DW) is a set of elements connected by a hierarchical relationship. The elements are used to view summaries of data at different levels of abstraction. In order to support an efficient processing of such summaries, a dimension is usually required to satisfy different classes of integrity constraints. In scenarios where the constraints properly capture the semantics of the DW data, but they are not satisfied by the dimension, the problem of repairing (correcting) the dimension arises. In this paper, we study the problem of repairing a dimension in the context of two main classes of integrity constraints: strictness and covering constraints. We introduce the notion of minimal repair of a dimension: a new dimension that is consistent with respect to the set of integrity constraints, which is obtained by applying a minimal number of updates to the original dimension. We study the complexity of obtaining minimal repairs, and show how they can be characterized using Datalog programs with weak constraints under the stable model semantics. (c) 2012 Elsevier B.V. All rights reserved.

