Phase transitions on a multiplex of swarmalators.

Dynamics of bidirectionally coupled swarmalators subject to attractive and repulsive couplings is analyzed. The probability of two elements in different layers being connected strongly depends on a defined vision range r_{c} which appears to lead both layers in different patterns while varying its values. Particularly, the interlayer static sync π has been found and its stability is proven. First-order transitions are observed when the repulsive coupling strength σ_{r} is very small for a fixed r_{c} and, moreover, in the absence of the repulsive coupling, they also appear for sufficiently large values of r_{c}. For σ_{r}=0 and for sufficiently small values of r_{c}, both layers achieve a second-order transition in a surprising two steps that are characterized by the drop of the energy of the internal phases while increasing the value of the interlayer attractive coupling σ_{a} and later a smooth jump, up to high energy value where synchronization is achieved. During these transitions, the internal phases present rotating waves with counterclockwise and later clockwise directions until synchronization, as σ_{a} increases. These results are supported by simulations and animations added as supplemental materials.

An integrated model to study varietal diversity in traditional agroecosystems.

Agricultural diversity is one of the bases of traditional agroecosystems, having great environmental and cultural importance. The current loss of agricultural diversity is causing serious concern, mainly because of its essential role in supporting global and local food security. Stopping this loss requires a better understanding of how diversity is managed locally and what mechanisms sustain agricultural diversity. Here we propose a generalist agent-based model that couples biological, cultural, and social dynamics to obtain varietal diversity as an emergent phenomenon at the community level. With a mechanistic approach, we explore how four of the model dynamics can shape systems diversity. To validate the model, we performed a bibliographic review on Manihot esculenta and Zea mays case studies. The model yielded compatible results for manioc and maize varietal richness at both community and household levels.

Evolution of urban scaling: Evidence from Brazil.

During the last years, the new science of cities has been established as a fertile quantitative approach to systematically understand the urban phenomena. One of its main pillars is the proposition that urban systems display universal scaling behavior regarding socioeconomic, infrastructural and individual basic services variables. This paper discusses the extension of the universality proposition by testing it against a broad range of urban metrics in a developing country urban system. We present an exploration of the scaling exponents for over 60 variables for the Brazilian urban system. Estimating those exponents is challenging from the technical point of view because the Brazilian municipalities' definition follows local political criteria and does not regard characteristics of the landscape, density, and basic utilities. As Brazilian municipalities can deviate significantly from urban settlements, urban-like municipalities were selected based on a systematic density cut-off procedure and the scaling exponents were estimated for this new subset of municipalities. To validate our findings we compared the results for overlaying variables with other studies based on alternative methods. It was found that the analyzed socioeconomic variables follow a superlinear scaling relationship with the population size, and most of the infrastructure and individual basic services variables follow expected sublinear and linear scaling, respectively. However, some infrastructural and individual basic services variables deviated from their expected regimes, challenging the universality hypothesis of urban scaling. We propose that these deviations are a product of top-down decisions/policies. Our analysis spreads over a time-range of 10 years, what is not enough to draw conclusive observations, nevertheless we found hints that the scaling exponent of these variables are evolving towards the expected scaling regime, indicating that the deviations might be temporally constrained and that the urban systems might eventually reach the expected scaling regime.

Factors associated with the diffusion rate of innovations: a pilot study from the perspective of the Brazilian Unified National Health System.

Budget Impact Analyses require a set of essential information on health technology innovation, including expected rates of adoption. There is an absence of studies investigating trends, magnitude of budgetary effects and determinants of diffusion rates for health technology innovations worldwide during the last decades. The present study proposes a pilot assessment on main determinants influencing diffusion rates of pharmaceutical innovations within the Brazilian Unified National Health System (SUS). Data from the Brazilian Health Informatics Department (DATASUS) was gathered to establish the main determinants of diffusion rates of health technology innovations in Brazil, specifically referring to pharmaceutical innovations incorporated in the Brazilian Program for Specialized Pharmaceutical Services (CEAF) at SUS. Information was retrieved on DATASUS relating to patients who had used one of the medicines incorporated into CEAF at least three years prior to the beginning of the study (2015) for treatment of each health condition available. Thus, data from patients adopting 10 different medicines were analyzed in the study. Results from the zero-one inflated beta model showed a higher influence on diffusion rates of pharmaceutical innovations due to: number of pharmaceutical competitors for treatment of the same disease available at CEAF (negative); medicine used in combination with other medication (positive); and innovative medicine within the SUS (positive). Further research on diffusion rates of health technology innovations is required, including wider scope of diseases and medications, potential confusion factors and other variables that may influence rates of adoption in different health systems.

Coexistence of competing metabolic pathways in well-mixed populations.

Understanding why strains with different metabolic pathways that compete for a single limiting resource coexist is a challenging issue within a theoretical perspective. Previous investigations rely on mechanisms such as group or spatial structuring to achieve a stable coexistence between competing metabolic strategies. Nevertheless, coexistence has been experimentally reported even in situations where it cannot be attributed to spatial effects [Heredity 100, 471 (2008)HDTYAT0018-067X10.1038/sj.hdy.6801073]. According to that study a toxin expelled by one of the strains can be responsible for the stable maintenance of the two strain types. We propose a resource-based model in which an efficient strain with a slow metabolic rate competes with a second strain type which presents a fast but inefficient metabolism. Moreover, the model assumes that the inefficient strain produces a toxin as a by-product. This toxin affects the growth rate of both strains with different strength. Through an extensive exploration of the parameter space we determine the situations at which the coexistence of the two strains is possible. Interestingly, we observe that the resource influx rate plays a key role in the maintenance of the two strain types. In a scenario of resource scarcity the inefficient is favored, though as the resource influx rate is augmented the coexistence becomes possible and its domain is enlarged.

Multilevel selection in a resource-based model.

In the present work we investigate the emergence of cooperation in a multilevel selection model that assumes limiting resources. Following the work by R. J. Requejo and J. Camacho [Phys. Rev. Lett. 108, 038701 (2012)], the interaction among individuals is initially ruled by a prisoner's dilemma (PD) game. The payoff matrix may change, influenced by the resource availability, and hence may also evolve to a non-PD game. Furthermore, one assumes that the population is divided into groups, whose local dynamics is driven by the payoff matrix, whereas an intergroup competition results from the nonuniformity of the growth rate of groups. We study the probability that a single cooperator can invade and establish in a population initially dominated by defectors. Cooperation is strongly favored when group sizes are small. We observe the existence of a critical group size beyond which cooperation becomes counterselected. Although the critical size depends on the parameters of the model, it is seen that a saturation value for the critical group size is achieved. The results conform to the thought that the evolutionary history of life repeatedly involved transitions from smaller selective units to larger selective units.

Analysis of the evolution and determinants of income-related inequalities in the Brazilian health system, 1998 - 2008.

OBJECTIVE: To analyze the evolution and determinants of income-related inequalities in the Brazilian health system between 1998 and 2008. METHODS: Data from the National Household Sampling Surveys of 1998, 2003, and 2008 were used to analyze inequalities in health and health care. Health was measured by self-reported health status, physical limitations, and chronic illness. Hospitalization and physician and dentist visits were proxies for health care utilization. Income was a proxy for socioeconomic status. Concentration indices were calculated before and after standardization for all dependent variables. Decomposition analysis was used to identify the main determinants of inequality in health care utilization. RESULTS: In all three periods analyzed, the poor reported worse health status, while the wealthy reported more chronic diseases; health care utilization was pro-rich for medical and dental services. Yet, income-related inequality in health care utilization has been declining. Private health insurance, education, and income are the major contributors to the inequalities identified. CONCLUSIONS: Income-related inequality in the use of medical and dental health care is gradually declining in Brazil. The decline is associated with implementation of pro-equity policies and programs, such as the Community Health Agents Program and the Family Health Program.

Analysis of the evolution and determinants of income-related inequalities in the Brazilian health system, 1998 - 2008 / Análisis de la evolución y los determinantes de las desigualdades relacionadas con los ingresos en el sistema de salud de Brasil, 1998 - 2008

OBJECTIVE: To analyze the evolution and determinants of income-related inequalities in the Brazilian health system between 1998 and 2008. METHODS: Data from the National Household Sampling Surveys of 1998, 2003, and 2008 were used to analyze inequalities in health and health care. Health was measured by self-reported health status, physical limitations, and chronic illness. Hospitalization and physician and dentist visits were proxies for health care utilization. Income was a proxy for socioeconomic status. Concentration indices were calculated before and after standardization for all dependent variables. Decomposition analysis was used to identify the main determinants of inequality in health care utilization. RESULTS: In all three periods analyzed, the poor reported worse health status, while the wealthy reported more chronic diseases; health care utilization was pro-rich for medical and dental services. Yet, income-related inequality in health care utilization has been declining. Private health insurance, education, and income are the major contributors to the inequalities identified. CONCLUSIONS: Income-related inequality in the use of medical and dental health care is gradually declining in Brazil. The decline is associated with implementation of pro-equity policies and programs, such as the Community Health Agents Program and the Family Health Program.

OBJETIVOS: Analizar la evolución y los determinantes de las desigualdades relacionadas con los ingresos en el sistema de salud brasileño entre 1998 y 2008. MÉTODOS: Se utilizaron los datos de la Encuesta Nacional de Hogares de 1998, 2003 y 2008. La salud se midió según el estado de salud autoevaluado, las limitaciones físicas y las enfermedades crónicas. Las hospitalizaciones y las consultas médicas y odontológicas se usaron como medición indirecta de la utilización de la atención sanitaria, y los ingresos para estimar el nivel socioeconómico. Los índices de concentración para todas las variables dependientes se calcularon antes y después de su estandarización. Se empleó análisis de descomposición para identificar los principales determinantes de desigualdad en la utilización de la atención sanitaria. RESULTADOS: En los tres períodos analizados, las personas con menor nivel socioeconómico informaron un peor estado de salud, mientras que las de mayor nivel informaron más enfermedades crónicas y tuvieron una mayor utilización de la atención sanitaria (servicios médicos y odontológicos). A pesar de esto, la desigualdad en la utilización de la atención sanitaria relacionada con los ingresos ha ido disminuyendo. El seguro de salud privado, la educación y los ingresos son los principales factores que contribuyen a las desigualdades identificadas. CONCLUSIONES: Las desigualdades en la utilización de los servicios médicos y odontológicos relacionadas con los ingresos han disminuido gradualmente en Brasil. Esta disminución se asoció con la aplicación en el país de políticas y programas que favorecen la equidad, como el Programa de Agentes de Salud Comunitarios y el Programa de Salud Familiar.