DM - GISC - Artículos de Revistas

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Calibration of a Dust Scattering Instrument Using Tomographic Techniques and Its Application to a Dust Sensor Instrument
(MDPI, 2023-06-01) Santalices Martin, David Maria; Martinez Garcia, Mateo; Belmar Rubio, Jesus; Benito Bricio, Daniel; Briz Pacheco, Susana; Melendez Sanchez, Juan; Castro Gonzalez, Antonio Jesus De; Comunidad de Madrid; Ministerio de Economía y Competitividad (España)
The characterization of suspended dust near the Martian surface is extremely relevant to understand the climate of Mars. In this frame, a Dust Sensor instrument, an infrared device designed to obtain the effective parameters of Martian dust using the scattering properties of the dust particles, was developed. The purpose of this article is to present a novel methodology to calculate, from experimental data, an instrumental function of the Dust Sensor that allows solving the direct problem and providing the signal that this instrument would provide given a distribution of particles. The experimental method is based on recording the signal measured when a Lambertian reflector is gradually introduced into the interaction volume at different distances from the detector and source and applying tomography techniques (inverse Radon transform) to obtain the image of a section of the interaction volume. This method provides a complete mapping of the interaction volume experimentally, which determines the Wf function. The method was applied to solve a specific case study. Among the advantages of this method, it should be noted that it avoids assumptions and idealizations of the dimensions of the volume of interaction and reduces the time required to carry out simulations.
Hierarchical invasion of cooperation in complex networks
(IOP, 2018-02-01) Vilone, Daniele; Caprano, Valerio; Ramasco, Jose J.; Ministerio de Economía y Competitividad (España)
The emergence and survival of cooperation is one of the hardest problems still open in science. Several factors such as the existence of punishment, repeated interactions, topological effects and the formation of prestige may all contribute to explain the counter-intuitive prevalence of cooperation in natural and social systems. The characteristics of the interaction networks have been also signaled as an element favoring the persistence of cooperators. Here we consider the invasion dynamics of cooperative behaviors in complex topologies. The invasion of a heterogeneous network fully occupied by defectors is performed starting from nodes with a given number of connections (degree) k(0). The system is then evolved within a Prisoner's Dilemma game and the outcome is analyzed as a function of k0 and the degree k of the nodes adopting cooperation. Carried out using both numerical and analytical approaches, our results show that the invasion proceeds following preferentially a hierarchical order in the nodes from those with higher degree to those with lower degree. However, the invasion of cooperation will succeed only when the initial cooperators are numerous enough to form a cluster from which cooperation can spread. This implies that the initial condition has to be a suitable equilibrium between high degree and high numerosity. These findings have potential applications to the problem of promoting pro-social behaviors in complex networks.
This is how we do it: How social norms and social identity shape decision making under uncertainty
(MDPI, 2018-12-09) Lipari, Francesca
Vegetation cover and biodiversity reduce parasite infection in wild hosts across ecological levels and scales
(Wiley, 2023-05-01) Andreazzi, Cecilia S.; Martínez-Vaquero, Luis A.; Winck, Gisele R.; Cardoso, Thiago S.; Teixeira, Bernardo R.; Xavier, Samanta C.C.; Gentile, Rosana; Jansen, Ana María; D'Andrea, Paulio S.; European Commission; Ministerio de Ciencia e Innovación (España)
Land use changes and biodiversity loss critically disrupts ecosystem functioning and are major drivers of infectious disease outbreaks. Trypanosoma cruzi, the agent of Chagas disease, is a multi-host parasite whose epidemiology has changed due to the expansion of anthropogenic activities over natural areas. We aimed to understand the ecological processes increasing parasite prevalence at the individual, the community and the landscape levels using the largest database on small mammal infection by T. cruzi in Brazil. We applied machine learning techniques and structural equation models to show that allometric traits and the relative abundance of rodents in the community were important predictors of infection risk, followed by variables associated with the landscape environmental quality. Natural vegetation cover change and the taxonomic and functional dimensions of biodiversity indirectly reduced infection through its effect on the abundance distribution and composition of host communities. According to our findings, approaches to biodiversity conservation and restoration based on the integration of social inclusion and human welfare would contribute to regulate the prevalence of T. cruzi in wild hosts, which may reduce overall transmission risk.
On the networked architecture of genotype spaces and its critical effects on molecular evolution
(2018-07-04) Aguirre, Jacobo; Catalan, Pablo; Cuesta, José A.; Manrubia, Susanna C.
Evolutionary dynamics is often viewed as a subtle process of change accumulation that causes a divergence among organisms and their genomes. However, this interpretation is an inheritance of a gradualistic view that has been challenged at the macroevolutionary, ecological and molecular level. Actually, when the complex architecture of genotype spaces is taken into account, the evolutionary dynamics of molecular populations becomes intrinsically non-uniform, sharing deep qualitative and quantitative similarities with slowly driven physical systems: nonlinear responses analogous to critical transitions, sudden state changes or hysteresis, among others. Furthermore, the phenotypic plasticity inherent to genotypes transforms classical fitness landscapes into multiscapes where adaptation in response to an environmental change may be very fast. The quantitative nature of adaptive molecular processes is deeply dependent on a network-of-networks multilayered structure of the map from genotype to function that we begin to unveil.
Collaborative hierarchy maintains cooperation in asymmetric games
(2018-03-29) Antonioni, Alberto; Pereda Garcia, Maria; Cronin, K. A.; Tomassini, M.; Sánchez, Angel; Ministerio de Economía y Competitividad (España)
The interplay of social structure and cooperative behavior is under much scrutiny lately as behavior in social contexts becomes increasingly relevant for everyday life. Earlier experimental work showed that the existence of a social hierarchy, earned through competition, was detrimental for the evolution of cooperative behaviors. Here, we study the case in which individuals are ranked in a hierarchical structure based on their performance in a collective effort by having them play a Public Goods Game. In the first treatment, participants are ranked according to group earnings while, in the second treatment, their rankings are based on individual earnings. Subsequently, participants play asymmetric Prisoner's Dilemma games where higher-ranked players gain more than lower ones. Our experiments show that there are no detrimental effects of the hierarchy formed based on group performance, yet when ranking is assigned individually we observe a decrease in cooperation. Our results show that different levels of cooperation arise from the fact that subjects are interpreting rankings as a reputation which carries information about which subjects were cooperators in the previous phase. Our results demonstrate that noting the manner in which a hierarchy is established is essential for understanding its effects on cooperation.
Emergence and Evolution of Cooperation Under Resource Pressure
(Springer Nature, 2017-03-31) Pereda, María; Zurro, Debora; Santos Martin, Jose Ignacio; Briz I Godino, Ivan; Alvarez, Myriam; Caro, Jorge; Galan, Jose M.; European Commission; Ministerio de Ciencia e Innovación (España)
We study the influence that resource availability has on cooperation in the context of hunter-gatherer societies. This paper proposes a model based on archaeological and ethnographic research on resource stress episodes, which exposes three different cooperative regimes according to the relationship between resource availability in the environment and population size. The most interesting regime represents moderate survival stress in which individuals coordinate in an evolutionary way to increase the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival. Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share the part of the resource that is not strictly necessary for survival, thereby collectively lowering the chances of starving. Our findings shed further light on the emergence and evolution of cooperation in hunter-gatherer societies.
Getting the best of both worlds? Developing complementary equation-based and agent-based models
(Springer, 2019-02-15) Gräbner, Claudius; Bale, Catherine S. E.; Furtado, Bernardo Alves; Álvarez-Pereira, Brais; Gentile, James E.; Henderson, Heath; Lipari, Francesca
We argue that building agent-based and equation-based versions of the same theoretical model is a fruitful way of gaining insights into real-world phenomena. We use the epistemological concept of "models as isolations and surrogate systems" as the philosophical underpinning of this argument. In particular, we show that agent-based and equation-based approaches align well when used simultaneously and, contrary to some common misconceptions, should be considered complements rather than substitutes. We illustrate the usefulness of the approach by examining a model of the long-run relationship between economic development and inequality (i.e., the Kuznets hypothesis).
Neuronal differentiation influences progenitor arrangement in the vertebrate neuroepithelium
(The Company of Biologists, 2019-12) Guerrero Contreras, Pilar; Pérez-Carrasco, Rubén; Zagorski, Marcin; Page, David; Kicheva, Anna; Briscoe, James; Page, Karen M.; European Commission; Ministerio de Ciencia, Innovación y Universidades (España)
Cell division, movement and differentiation contribute to pattern formation in developing tissues. This is the case in the vertebrate neural tube, in which neurons differentiate in a characteristic pattern from a highly dynamic proliferating pseudostratified epithelium. To investigate how progenitor proliferation and differentiation affect cell arrangement and growth of the neural tube, we used experimental measurements to develop a mechanical model of the apical surface of the neuroepithelium that incorporates the effect of interkinetic nuclear movement and spatially varying rates of neuronal differentiation. Simulations predict that tissue growth and the shape of lineage-related clones of cells differ with the rate of differentiation. Growth is isotropic in regions of high differentiation, but dorsoventrally biased in regions of low differentiation. This is consistent with experimental observations. The absence of directional signalling in the simulations indicates that global mechanical constraints are sufficient to explain the observed differences in anisotropy. This provides insight into how the tissue growth rate affects cell dynamics and growth anisotropy and opens up possibilities to study the coupling between mechanics, pattern formation and growth in the neural tube.
Investigating peer and sorting effects within an adaptive multiplex network model
(MDPI, 2019-01) Lipari, Francesca; Stella, Massimo; Antonioni, Alberto; Ministerio de Economía y Competitividad (España)
Individuals have a strong tendency to coordinate with all their neighbors on social and economics networks. Coordination is often influenced by intrinsic preferences among the available options, which drive people to associate with similar peers, i.e., homophily. Many studies reported that behind coordination game equilibria there is the individuals’ heterogeneity of preferences and that such heterogeneity is given a priori. We introduce a new mechanism which allows us to analyze the issue of heterogeneity from a cultural evolutionary point of view. Our framework considers agents interacting on a multiplex network who deal with coordination issues using social learning and payoff-driven dynamics. Agents form their heterogeneous preference through learning on one layer and they play a pure coordination game on the other layer. People learn from their peers that coordination is good and they also learn how to reach it either by conformism behavior or sorting strategy. We find that the presence of the social learning mechanism explains the rising and the endurance of a segregated society when members are diverse. Knowing how culture affects the ability to coordinate is useful for understanding how to reach social welfare in a diverse society.
Prediction of the liquid-crystal phase behavior of hard right triangles from fourth-virial density-functional theories
(APS, 2023-07) Velasco, Enrique; Martínez-Ratón, Yuri; Ministerio de Ciencia, Innovación y Universidades (España); Agencia Estatal de Investigación (España)
We have used an extended scaled-particle theory that incorporates four-body correlations through the fourth-order virial coefficient to analyze the orientational properties of a fluid of hard right isosceles triangles. This fluid has been analyzed by computer simulation studies, with clear indications of strong octatic correlations present in the liquid-crystal phase, although the more symmetric order tetratic phase would seem to be the most plausible candidate. Standard theories based on the second virial coefficient are unable to reproduce this behavior. Our extended theory predicts that octatic correlations, associated to a symmetry under global rotations of the oriented fluid by 45∘, are highly enhanced, but not enough to give rise to a thermodynamically stable phase with strict octatic symmetry. We discuss different scenarios to improve the theoretical understanding of the elusive octatic phase in this intriguing fluid.
Are more intelligent people happier? Emotional intelligence as mediator between need for relatedness, happiness and flourishing
(MDPI, 2019-02-02) Callea, Antonino; De Rosa, Dalilla; Ferri, Giovanni; Lipari, Francesca; Costanzi, Marco
The psychology of sustainability and sustainable development aims to study the personal characteristics that promote effective and sustainable well-being for individuals and environments from a psychological research perspective. According to the self-determination theory, the psychological need for relatedness is positively associated with happiness and flourishing. In turn, emotional intelligence, i.e., understanding and managing one’s own emotions and recognizing others’ emotions, may play a key role in this association. Therefore, the present study investigates the mediating role of emotional intelligence in the relationship between need for relatedness and both happiness and flourishing. Basic Psychological Needs scales (BPNs), Emotional Intelligence Scale (EIS), Flourishing Scale, and Happiness Scale were administered to 216 Italian participants (age range 15–66 years old). A mediation model via a structural equation model for path analysis was tested. The results showed that the psychological need for relatedness positively associated with both happiness and flourishing and that emotional intelligence mediated these associations. These results suggest that important interventions may be performed to promote flourishing and happiness, enhancing emotional intelligence through specific training differently from need for relatedness that, instead, can be considered substantially stable.
Novel regulatory mechanism of establishment genes of conjugative plasmids
(Oxford University Press, 2019-12-14) Val Calvo, Jorge; Luque-Ortega, Juan R.; Crespo, Isidro; Miguel-Arribas, Andrés; Abia, David; Sanchez Hevia, Dione L.; Serrano, Ester; Gago-Córdoba, César; Ares García, Saul; Alfonso, Carlos; Rojo, Fernando; Wu, Ling J.; Boer, D. Roeland; Meijer, Wilfried J.; Ministerio de Economía y Competitividad (España)
The principal route for dissemination of antibiotic resistance genes is conjugation by which a conjugative DNA element is transferred from a donor to a recipient cell. Conjugative elements contain genes that are important for their establishment in the new host, for instance by counteracting the host defense mechanisms acting against incoming foreign DNA. Little is known about these establishment genes and how they are regulated. Here, we deciphered the regulation mechanism of possible establishment genes of plasmid p576 from the Gram-positive bacterium Bacillus pumilus. Unlike the ssDNA promoters described for some conjugative plasmids, the four promoters of these p576 genes are repressed by a repressor protein, which we named Reg(576). Reg(576) also regulates its own expression. After transfer of the DNA, these genes are de-repressed for a period of time until sufficient Reg(576) is synthesized to repress the promoters again. Complementary in vivo and in vitro analyses showed that different operator configurations in the promoter regions of these genes lead to different responses to Reg(576). Each operator is bound with extreme cooperativity by two Reg(576)-dimers. The X-ray structure revealed that Reg(576) has a Ribbon-Helix-Helix core and provided important insights into the high cooperativity of DNA recognition.
Abrupt onset of the capillary-wave spectrum at wall-fluid interfaces
(Royal Society of Chemistry, 2023-08-14) Parry, Andrew O.; Rascón, Carlos; Ministerio de Ciencia e Innovación (España); Agencia Estatal de Investigación (España)
Surfaces between 3D solids and fluids exhibit a wide variety of phenomena both at equilibrium, such as roughening transitions, interfacial fluctuations and wetting, and also out-of-equilibrium, such as the surface growth of driven interfaces. These phenomena are described very successfully using lower dimensional (2D) effective models which focus on the physics associated with emergent mesoscopic lengths scales, parallel to the interface, where the 2D-like behaviour is physically transparent. However, the precise conditions under which this dimensional reduction is justifiable have remained unclear. Here we show that, for a wall-fluid interface, a dimensional reduction from 3D-like to 2D-like behaviour - identified via the decay of density correlations - occurs abruptly at a specific value of the contact angle, and indicates the beginning of interfacial-like 2D behaviour and the spontaneous onset of the capillary-wave spectrum. The reduction from 3D to 2D is characterised by the divergence of a correlation length perpendicular to the interface revealing a morphological change in the nature of density correlations. Counter-intuitive effects occur, including that 3D behaviour can persist up to the wetting temperature and also that 2D behaviour can begin when no wetting layer is present and the adsorption is negative.
Effect of network topology and node centrality on trading
(Springer Nature, 2020-07-06) Maciel Cardoso, Felipe; Gracia-Lázaro, Carlos; Moisan, Frederic; Goyal, Sanjeev; Sánchez, Angel; Moreno, Yamir; Ministerio de Ciencia e Innovación (España)
Global supply networks in agriculture, manufacturing, and services are a defning feature of themodern world. The efciency and the distribution of surpluses across diferent parts of thesenetworks depend on the choices of intermediaries. This paper conducts price formation experimentswith human subjects located in large complex networks to develop a better understanding of theprinciples governing behavior. Our frst experimental fnding is that prices are larger and that tradeis signifcantly less efcient in small-world networks as compared to random networks. Our secondexperimental fnding is that location within a network is not an important determinant of pricing.An examination of the price dynamics suggests that traders on cheapest -and hence active- pathsraise prices while those of these paths lower them. We construct an agent-based model (ABM) thatembodies this rule of thumb. Simulations of this ABM yield macroscopic patterns consistent with the experimental fndings. Finally, we extrapolate the ABM on to signifcantly larger random and smallworld networks and fnd that network topology remains a key determinant of pricing and efciency.
Grounding Social Foundations for Integrated Assessment Models of Climate Change
(Wiley Periodicals LLC, 2020-06-14) Mathias, Jean-Denis; Debeljak, Marko; Deffuant, Guillaume; Diemer, Arnaud; Obergassel, Wolfgang; Pellaud, Francine; Sánchez, Angel; Trajanov, Aneta; Videira, Nuno
Integrated assessment models (IAMs) are commonly used by decision makers in order to deriveclimate policies. IAMs are currently based on climate-economics interactions, whereas the role of socialsystem has been highlighted to be of prime importance on the implementation of climate policies. Beyondexisting IAMs, we argue that it is therefore urgent to increase efforts in the integration of social processeswithin IAMs. For achieving such a challenge, we present some promising avenues of research based on thesocial branches of economics. We finally present the potential implications yielded by such social IAMs.
Cooperation, social norm internalization, and hierarchical societies
(Springer Nature, 2020-09-21) Lozano, Pablo; Gavrilets, Sergey; Sánchez, Angel; Ministerio de Ciencia, Innovación y Universidades (España)
Many animal and human societies exhibit hierarchical structures with different degrees of steepness. Some of these societies also show cooperative behavior, where cooperation means working together for a common benefit. However, there is an increasing evidence that rigidly enforced hierarchies lead to a decrease of cooperation in both human and non-human primates. In this work, we address this issue by means of an evolutionary agent-based model that incorporates fights as social interactions governing a dynamic ranking, communal work to produce a public good, and norm internalization, i.e. a process where acting according to a norm becomes a goal in itself. Our model also includes the perception of how much the individual is going to retain from her cooperative behavior in future interactions. The predictions of the model resemble the principal characteristics of human societies. When ranking is unconstrained, we observe a high concentration of agents in low scores, while a few ones climb up the social hierarchy and exploit the rest, with no norm internalization. If ranking is constrained, thus leading to bounded score differences between agents, individual positions in the ranking change more, and the typical structure shows a division of the society in upper and lower classes. In this case, we observe that there is a significant degree of norm internalization, supporting large fractions of the population cooperating in spite of the rank differences. Our main results are robust with respect to the model parameters and to the type of rank constraint. We thus provide a mechanism that can explain how hierarchy arises in initially egalitarian societies while keeping a large degree of cooperation.
Toward understanding the impact of artificial intelligence on labor
(2019-04-02) Frank, Morgan R.; Autor, David; Bessen, James E.; Brynjolfsson, Erik; Cebrian, Manuel; Deming, David J.; Feldman, Maryann; Groh, Matthew; Lobo, Jose; Moro, Esteban; Wang, Dashun; Youn, Hyejin; Rahwan, Iyad
Rapid advances in artificial intelligence (AI) and automation technologies have the potential to significantly disrupt labor markets. While AI and automation can augment the productivity of some workers, they can replace the work done by others and will likely transform almost all occupations at least to some degree. Rising automation is happening in a period of growing economic inequality, raising fears of mass technological unemployment and a renewed call for policy efforts to address the consequences of technological change. In this paper we discuss the barriers that inhibit scientists from measuring the effects of AI and automation on the future of work. These barriers include the lack of high-quality data about the nature of work (e.g., the dynamic requirements of occupations), lack of empirically informed models of key microlevel processes (e.g., skill substitution and human-machine complementarity), and insufficient understanding of how cognitive technologies interact with broader economic dynamics and institutional mechanisms (e.g., urban migration and international trade policy). Overcoming these barriers requires improvements in the longitudinal and spatial resolution of data, as well as refinements to data on workplace skills. These improvements will enable multidisciplinary research to quantitatively monitor and predict the complex evolution of work in tandem with technological progress. Finally, given the fundamental uncertainty in predicting technological change, we recommend developing a decision framework that focuses on resilience to unexpected scenarios in addition to general equilibrium behavior.
Large scale and information effects on cooperation in public good games
(Springer, 2019-10-21) Pereda García, María; Tamarit, Ignacio; Antonioni, Alberto; Cuesta Ruiz, Jose Antonio; Hernández, Penélope; Sánchez, Angel; Ministerio de Economía y Competitividad (España); Agencia Estatal de Investigación (España)
The problem of public good provision is central in economics and touches upon many challenging societal issues, ranging from climate change mitigation to vaccination schemes. However, results which are supposed to be applied to a societal scale have only been obtained with small groups of people, with a maximum group size of 100 being reported in the literature. This work takes this research to a new level by carrying out and analysing experiments on public good games with up to 1000 simultaneous players. The experiments are carried out via an online protocol involving daily decisions for extended periods. Our results show that within those limits, participants' behaviour and collective outcomes in very large groups are qualitatively like those in smaller ones. On the other hand, large groups imply the difficulty of conveying information on others' choices to the participants. We thus consider different information conditions and show that they have a drastic effect on subjects' contributions. We also classify the individual decisions and find that they can be described by a moderate number of types. Our findings allow to extend the conclusions of smaller experiments to larger settings and are therefore a relevant step forward towards the understanding of human behaviour and the organisation of our society.
How to Hide One's Relationships from Link Prediction Algorithms
(Springer, 2019-08-01) Waniek, Marcin; Zhou, Kai; Vorobeychik, Yevgeniy; Moro, Esteban; Michalak, Tomasz P.; Rahwan, Talal; Ministerio de Economía y Competitividad (España)
Our private connections can be exposed by link prediction algorithms. To date, this threat has only been addressed from the perspective of a central authority, completely neglecting the possibility that members of the social network can themselves mitigate such threats. We fill this gap by studying how an individual can rewire her own network neighborhood to hide her sensitive relationships. We prove that the optimization problem faced by such an individual is NP-complete, meaning that any attempt to identify an optimal way to hide one’s relationships is futile. Based on this, we shift our attention towards developing effective, albeit not optimal, heuristics that are readily-applicable by users of existing social media platforms to conceal any connections they deem sensitive. Our empirical evaluation reveals that it is more beneficial to focus on “unfriending” carefully-chosen individuals rather than befriending new ones. In fact, by avoiding communication with just 5 individuals, it is possible for one to hide some of her relationships in a massive, real-life telecommunication network, consisting of 829,725 phone calls between 248,763 individuals. Our analysis also shows that link prediction algorithms are more susceptible to manipulation in smaller and denser networks. Evaluating the error vs. attack tolerance of link prediction algorithms reveals that rewiring connections randomly may end up exposing one’s sensitive relationships, highlighting the importance of the strategic aspect. In an age where personal relationships continue to leave digital traces, our results empower the general public to proactively protect their private relationships.

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