Heterogeneous contributions can jeopardize cooperation in the public goods game.

When studying social dilemma games, a crucial question arises regarding the impact of general heterogeneity on cooperation, which has been shown to have positive effects in numerous studies. Here, we demonstrate that heterogeneity in the contribution value for the focal public goods game can jeopardize cooperation. We show that there is an optimal contribution value in the homogeneous case that most benefits cooperation depending on the lattice. In a heterogeneous scenario, where strategy and contribution coevolve, cooperators making contributions higher than the optimal value end up harming those who contribute less. This effect is notably detrimental to cooperation in the square lattice with von Neumann neighborhood, while it can have no impact in other lattices. Furthermore, in parameter regions where a higher-contributing cooperator cannot normally survive alone, the exploitation of lower-value contribution cooperators allows their survival, resembling a parasitic behavior. To obtain these results, we examined the effect of various distributions for the contribution values in the initial condition and we conducted Monte Carlo simulations.

A single active ring model with velocity self-alignment.

Cellular tissue behavior is a multiscale problem. At the cell level, out of equilibrium, biochemical reactions drive physical cell-cell interactions in a typical active matter process. Cell modeling computer simulations are a robust tool to explore countless possibilities and test hypotheses. Here, we introduce a two-dimensional, extended active matter model for biological cells. A ring of interconnected self-propelled particles represents the cell. Neighboring particles are subject to harmonic and bending potentials. Within a characteristic time, each particle's self-velocity tends to align with its scattering velocity after an interaction. Translational modes, rotational modes, and mixtures of these appear as collective states. Using analytical results derived from active Brownian particles, we identify effective characteristic time scales for ballistic and diffusive movements. Finite-size scale investigation shows that the ring diffusion increases linearly with its size when in collective movement. A study on the ring shape reveals that all collective states are present even when bending forces are weak. In that case, when in a translational mode, the collective velocity aligns with the largest ring's direction in a spontaneous polarization emergence.

Symbiotic behaviour in the public goods game with altruistic punishment.

Finding ways to overcome the temptation to exploit one another is still a challenge in behavioural sciences. In the framework of evolutionary game theory, punishing strategies are frequently used to promote cooperation in competitive environments. Here, we introduce altruistic punishers in the spatial public goods game. This strategy acts as a cooperator in the absence of defectors, otherwise it will punish all defectors in their vicinity while bearing a cost to do so. We observe three distinct behaviours in our model: i) in the absence of punishers, cooperators (who don't punish defectors) are driven to extinction by defectors for most parameter values; ii) clusters of punishers thrive by sharing the punishment costs when these are low; iii) for higher punishment costs, punishers, when alone, are subject to exploitation but in the presence of cooperators can form a symbiotic spatial structure that benefits both. This last observation is our main finding since neither cooperation nor punishment alone can survive the defector strategy in this parameter region and the specificity of the symbiotic spatial configuration shows that lattice topology plays a central role in sustaining cooperation. Results were obtained by means of Monte Carlo simulations on a square lattice and subsequently confirmed by a pairwise comparison of different strategies' payoffs in diverse group compositions, leading to a phase diagram of the possible states.

Forma clínica indeterminada da doença de Chagas e o risco potencial de evento isquêmico / Indeterminate clinical form of Chagas disease and the potencial risk of ischemic event / Forma clínica indeterminada de la enfermedad de Chagas y potencial riesgo de evento isquémico

Acidentes vasculares cerebrais ou isquêmicos transitórios são eventos raros em pacientes jovens sem fatores de risco clássicos, correspondendo muitas vezes a eventos não definidos etiologicamente e caracterizados como fenômenos tromboembólicos criptogênicos. A doença de Chagas é um fator de risco que deve ser considerado como potencial causa etiológica quando especificamos áreas endêmicas, tanto pelo conhecido mecanismo cardioembólico de acometimento cardíaco como pelas demais formas sem acometimento cardíaco, uma vez que já é descrita como fator de risco independente para doenças cerebrovasculares. Este estudo demonstra, por meio de um relato de caso, o desfecho de uma paciente portadora da doença de Chagas crônica, na forma indeterminada, sem fatores de risco clássicos. A paciente foi acometida por um ataque isquêmico transitório, tendo como etiologia presumida a doença de Chagas, que pode determinar um perfil pró-inflamatório e pró-coagulante, de modo a corroborar a tese de que o prognóstico da forma indeterminada pode não ser benigno. A associação entre a forma indeterminada e as doenças cerebrovasculares incorre na necessidade de anexar ao protocolo de investigação de acidente vascular encefálico (AVE) criptogênicos da doença de Chagas, quando se refere a áreas endêmicas, bem como em alertar as áreas da saúde para essa forma da doença, como forma de ajudar em medidas de prevenção de fenômenos tromboembólicos encefálicos.

Transient strokes or ischemic attacks are rare events in young patients without classic risk factors, often corresponding to events not defined etiologically and characterized as cryptogenic thromboembolic phenomena. Chagas disease is a risk factor that should be considered as a potential etiological cause when specifying endemic areas, both for the cardioembolic mechanism and for other forms without cardiac involvement, since it is described as an independent risk factor for cerebrovascular diseases. This study shows, by means of a case report, the outcome of a patient with chronic indeterminate Chagas disease without classic risk factors. The patient was affected by a transient ischemic attack, with the presumed etiology being Chagas disease, which can determinate a pro-inflammatory and pro-coagulant profile, thus corroborating that the prognosis of the indeterminate form may not be benign. The association between the indeterminate form and stroke incurs in the need to attach to the investigation protocol for cryptogenic stroke of Chagas disease, when referring to endemic areas, as well as to take a better look at this form to help in prevention measures for encephalic thromboembolic phenomena.

Los accidentes cerebrovasculares o accidentes isquémicos transitorios son eventos raros en pacientes jóvenes sin factores de riesgo clásicos, que a menudo corresponden a eventos no definidos etiológicamente caracterizándose como fenómenos tromboembólicos criptogénicos. La enfermedad de Chagas es un factor de riesgo que debe ser considerado como una posible causa etiológica cuando especificamos áreas endémicas, tanto por el conocido mecanismo cardioembólico de afectación cardíaca como por otras formas sin afectación cardíaca, puesto que la enfermedad ya está descrita como factor de riesgo independiente de enfermedades cerebrovasculares. Este estudio demuestra, a partir de un reporte de caso, el desenlace de un paciente con enfermedad de Chagas crónica en forma indeterminada sin factores de riesgo clásicos. La paciente sufrió un ataque isquémico transitorio, con la enfermedad de Chagas como presunta etiología, lo que puede determinar un perfil proinflamatorio y procoagulante, por lo que corroboró con la tesis de que el pronóstico de la forma indeterminada puede no ser tan benigno. La asociación entre la forma indeterminada y las enfermedades cerebrovasculares incurre en la necesidad de adjuntar la enfermedad de Chagas al protocolo de investigación de accidente cerebrovascular (ACV) criptogénico cuando se habla de áreas endémicas, así como de incrementar la visión de las áreas de salud a esta forma de enfermedad, para así contribuir con las medidas preventivas de los fenómenos tromboembólicos cerebrales.

Exchanging fluids The sociocultural implications of microbial, cultural, and ethnic admixture in Latin America.

Knowledge of evolutionary influences on patterns of human mating, social interactions, and differential health is increasing, yet these insights have rarely been applied to historical analyses of human population dynamics. The genetic and evolutionary forces behind biases in interethnic mating and in the health of individuals of different ethnic groups in Latin America and the Caribbean since the European colonization of America are still largely ignored. We discuss how historical and contemporary sociocultural interactions and practices are strongly influenced by population-level evolutionary forces. Specifically, we discuss the historical implications of functional (de facto) polygyny, sex-biased admixture, and assortative mating in Latin America. We propose that these three evolutionary mechanisms influenced mating patterns, shaping the genetic and cultural landscape across Latin America and the Caribbean. Further, we discuss how genetic differences between the original populations that migrated at different times into Latin America contributed to their accommodation to and survival in the different local ecologies and interethnic interactions. Relevant medical and social implications follow from the genetic and cultural changes reviewed.

Phase transitions in hard-core lattice gases on the honeycomb lattice.

We study lattice gas systems on the honeycomb lattice where particles exclude neighboring sites up to order k (k=1,...,5) from being occupied by another particle. Monte Carlo simulations were used to obtain phase diagrams and characterize phase transitions as the system orders at high packing fractions. For systems with first-neighbors exclusion (1NN), we confirm previous results suggesting a continuous transition in the two-dimensional Ising universality class. Exclusion up to second neighbors (2NN) lead the system to a two-step melting process where, first, a high-density columnar phase undergoes a first-order phase transition with nonstandard scaling to a solidlike phase with short-range ordered domains and, then, to fluidlike configurations with no sign of a second phase transition. 3NN exclusion, surprisingly, shows no phase transition to an ordered phase as density is increased, staying disordered even to packing fractions up to 0.98. The 4NN model undergoes a continuous phase transition with critical exponents close to the three-state Potts model. The 5NN system undergoes two first-order phase transitions, both with nonstandard scaling. We, also, propose a conjecture concerning the possibility of more than one phase transition for systems with exclusion regions further than 5NN based on geometrical aspects of symmetries.

The ecology of empire The dynamics of strategic differentiation-integration in two competing Western European biocultural groups.

We tracked the relative integration and differentiation among life history traits over the period spanning AD 1800-1999 in the Britannic and Gallic biocultural groups. We found that Britannic populations tended toward greater strategic differentiation, while Gallic populations tended toward greater strategic integration. The dynamics of between-group competition between these two erstwhile rival biocultural groups were hypothesized as driving these processes. We constructed a latent factor that specifically sought to measure between-group competition and residualized it for the logarithmic effects of time. We found a significantly asymmetrical impact of between-group competition, where the between-group competition factor appeared to be driving the diachronic integration in Gallic populations but had no significantly corresponding influence on the parallel process of diachronic differentiation in Britannic populations. This suggests that the latter process was attributable to some alternative and unmeasured causes, such as the resource abundance consequent to territorial expansion rather than contraction.

Sinistrality is associated with (slightly) lower general intelligence: A data synthesis and consideration of the secular trend in handedness.

The relationship between the general factor of intelligence (g) and handedness is investigated using a combined sample of 23511 respondents from three large databases: the NLSY'79 (US), NLSY'97 (US) and NCDS (UK). Dextrals - those who use their right hands were found to be 1.22 IQ points higher than sinistrals (left handers) after controlling for sex and age and correcting for sources of measurement error. To see if the association between IQ and handedness was strongest on the abilities that were the best measures of g, the method of correlated vectors was used to test for moderation. Across the three studies, g was found to very weakly negatively moderate the association between ability measure and handedness (ρ = -.023, K = 3, N = 23511), however in the NLSY'79, the coding speed subtest was an outlier in terms of the strength of its association with handedness. Its removal yielded indications of positive moderation in this dataset, which when aggregated boosted the overall vector correlation value to .539 (K = 3, N = 23511), suggesting that g might be an important moderator of this relationship. Secondary analysis of secular trend data on the changing percentage of sinistrals in Western populations indicates that overall, sinistrality has increased, entailing a g decline of .106 points over 150 years (.006 points per decade). The secular increase in sinistrality is consistent with other data indicating long-term declines in developmental stability and may stem from some combination of increasing mutation load and environmental stress in Western populations.

Benefits of Manometer in Non-Invasive Ventilatory Support.

Introduction Effective ventilation during cardiopulmonary resuscitation (CPR) is essential to reduce morbidity and mortality rates in cardiac arrest. Hyperventilation during CPR reduces the efficiency of compressions and coronary perfusion. Problem How could ventilation in CPR be optimized? The objective of this study was to evaluate non-invasive ventilator support using different devices. METHODS: The study compares the regularity and intensity of non-invasive ventilation during simulated, conventional CPR and ventilatory support using three distinct ventilation devices: a standard manual resuscitator, with and without airway pressure manometer, and an automatic transport ventilator. Student's t-test was used to evaluate statistical differences between groups. P values <.05 were regarded as significant. RESULTS: Peak inspiratory pressure during ventilatory support and CPR was significantly increased in the group with manual resuscitator without manometer when compared with the manual resuscitator with manometer support (MS) group or automatic ventilator (AV) group. CONCLUSION: The study recommends for ventilatory support the use of a manual resuscitator equipped with MS or AVs, due to the risk of reduction in coronary perfusion pressure and iatrogenic thoracic injury during hyperventilation found using manual resuscitator without manometer. Lacerda RS , de Lima FCA , Bastos LP , Vinco AF , Schneider FBA , Coelho YL , Fernandes HGC , Bacalhau JMR , Bermudes IMS , da Silva CF , da Silva LP , Pezato R . Benefits of manometer in non-invasive ventilatory support. Prehosp Disaster Med. 2017;32(6):615-620.

General intelligence is a source of individual differences between species: Solving an anomaly.

Burkart et al. present a paradox - general factors of intelligence exist among individual differences (g) in performance in several species, and also at the aggregate level (G); however, there is ambiguous evidence for the existence of g when analyzing data using a mixed approach, that is, when comparing individuals of different species using the same cognitive ability battery. Here, we present an empirical solution to this paradox.

Modeling of Droplet Evaporation on Superhydrophobic Surfaces.

When a drop of water is placed on a rough surface, there are two possible extreme regimes of wetting: the one called Cassie-Baxter (CB) with air pockets trapped underneath the droplet and the one called the Wenzel (W) state characterized by the homogeneous wetting of the surface. A way to investigate the transition between these two states is by means of evaporation experiments, in which the droplet starts in a CB state and, as its volume decreases, penetrates the surface's grooves, reaching a W state. Here we present a theoretical model based on the global interfacial energies for CB and W states that allows us to predict the thermodynamic wetting state of the droplet for a given volume and surface texture. We first analyze the influence of the surface geometric parameters on the droplet's final wetting state with constant volume and show that it depends strongly on the surface texture. We then vary the volume of the droplet, keeping the geometric surface parameters fixed to mimic evaporation and show that the drop experiences a transition from the CB to the W state when its volume reduces, as observed in experiments. To investigate the dependency of the wetting state on the initial state of the droplet, we implement a cellular Potts model in three dimensions. Simulations show very good agreement with theory when the initial state is W, but it disagrees when the droplet is initialized in a CB state, in accordance with previous observations which show that the CB state is metastable in many cases. Both simulations and the theoretical model can be modified to study other types of surfaces.

By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century.

It has been theorized that declines in general intelligence (g) due to genetic selection stemming from the inverse association between completed fertility and IQ and the Flynn effect co-occur, with the effects of the latter being concentrated on less heritable non-g sources of intelligence variance. Evidence for this comes from the observation that 19th century populations were more intellectually productive, and also exhibited faster simple reaction times than modern ones, suggesting greater information-processing ability and therefore higher g. This co-occurrence model is tested via examination of historical changes in the utilization frequencies of words from the highly g-loaded WORDSUM test across 5.9 million texts spanning the period 1850-2005. Consistent with predictions, words with higher difficulties (δ parameters from Item Response Theory) and stronger negative correlations between pass rates and completed fertility declined in use over time whereas less difficult and less strongly selected words, increased in use over time, consistent with a Flynn effect stemming in part from the vocabulary enriching effects of increases in population literacy. These findings persisted when explicitly controlled for word age, changing literacy rates and temporal autocorrelation. These trends constitute compelling evidence for the co-occurrence model.

Strategic differentiation and integration of genomic-level heritabilities facilitate individual differences in preparedness and plasticity of human life history.

Life history (LH) strategies refer to the pattern of allocations of bioenergetic and material resources into different domains of fitness. While LH is known to have moderate to high population-level heritability in humans, both at the level of the high-order factor (Super-K) and the lower-order factors (K, Covitality, and the General Factor of Personality), several important questions remain unexplored. Here, we apply the Continuous Parameter Estimation Model to measure individual genomic-level heritabilities (termed transmissibilities). These transmissibility values were computed for the latent hierarchical structure and developmental dynamics of LH strategy, and demonstrate; (1) moderate to high heritability of factor loadings of Super-K on its lower-order factors, evidencing biological preparedness, genetic accommodation, and the gene-culture coevolution of biased epigenetic rules of development; (2) moderate to high heritability of the magnitudes of the effect of the higher-order factors upon their loadings on their constituent factors, evidencing genetic constraints upon phenotypic plasticity; and (3) that heritability of the LH factors, their factor loadings, and the magnitudes of the correlations among factors, are weaker among individuals with slower LH speeds. The results were obtained from an American sample of 316 monozygotic (MZ) and 274 dizygotic (DZ) twin dyads and a Swedish sample of 863 MZ and 475 DZ twin dyads, and indicate that inter-individual variation in transmissibility is a function of individual socioecological selection pressures. Our novel technique, opens new avenues for analyzing complex interactions among heritable traits inaccessible to standard structural equation methods.

The more g-loaded, the more heritable, evolvable, and phenotypically variable: Homology with humans in chimpanzee cognitive abilities.

Expanding on a recent study that identified a heritable general intelligence factor (g) among individual chimpanzees from a battery of cognitive tasks, we hypothesized that the cognitive abilities that are more g-loaded would be more heritable and would present more additive genetic variance, in addition to showing more phenotypic variability. This pattern was confirmed, and is comparable to that found in humans, indicating fundamental homology. Finally, tool use presented the highest heritability, the largest amount of additive genetic variance and of phenotypic variance, consistent with previous findings indicating that it is associated with high interspecies variance and evolutionary rates in comparative primate studies.

Methodologically sound: Evaluating the psychometric approach to the assessment of human life history [reply to Copping, Campbell, and Muncer, 2014].

Copping, Campbell, and Muncer (2014) have recently published an article critical of the psychometric approach to the assessment of life history (LH) strategy. Their purported goal was testing for the convergent validation and examining the psychometric structure of the High-K Strategy Scale (HKSS). As much of the literature on the psychometrics of human LH during the past decade or so has emanated from our research laboratory and those of close collaborators, we have prepared this detailed response. Our response is organized into four main sections: (1) A review of psychometric methods for the assessment of human LH strategy, expounding upon the essence of our approach; (2) our theoretical/conceptual concerns regarding the critique, addressing the broader issues raised by the critique regarding the latent and hierarchical structure of LH strategy; (3) our statistical/methodological concerns regarding the critique, examining the validity and persuasiveness of the empirical case made specifically against the HKSS; and (4) our recommendations for future research that we think might be helpful in closing the gap between the psychometric and biometric approaches to measurement in this area. Clearly stating our theoretical positions, describing our existing body of work, and acknowledging their limitations should assist future researchers in planning and implementing more informed and prudent empirical research that will synthesize the psychometric approach to the assessment of LH strategy with complementary methods.

Psicologia evolucionista: uma perspectiva em expansão / Evolutionary psychology: an expanding approach

A Psicologia Evolucionista (PE) é um campo teórico da Psicologia cujo objetivo é entender a natureza humana à luz da perspectiva evolucionista do neodarwinismo. Apesar de ter surgido formalmente na década de 1980, a PE começou a se popularizar no Brasil apenas neste século. O objetivo do presente trabalho foi realizar uma investigação sistemática da produção acadêmica nacional na área até o momento, contrastando-a com a produção internacional no mesmo período. Para tanto, realizou-se uma revisão sistemática de literatura nas bases de dados: Biblioteca Virtual em Saúde, Banco de Teses da CAPES e PsycINFO. Utilizou-se a palavra-chave “Psicologia Evolucionista”, e sua correspondente em inglês, e a busca abrangeu todo o período disponível nas bases até 2010. Os trabalhos nacionais foram classificados de acordo com a temática de estudo e o método empregado, enquanto os internacionais foram apenas contabilizados. Os resultados permitiram constatar que, apesar do crescimento do número de publicações tanto no Brasil como no exterior, ainda são poucos os estudos empíricos na área no país. A predominância, nos estudos nacionais, é de revisões não sistemáticas de literatura e de temas relacionados a aspectos gerais da perspectiva evolucionista. Ressalta-se a necessidade de novos estudos brasileiros, sobretudo investigações empíricas e nas áreas de personalidade e psicopatologia.

Evolutionary Psychology (EP) is a broad theoretic field within Psychology that to understand human nature from the standpoint of evolutionary perspective of neo-Darwinism. Although its emergence dates back to the 1980’s, EP has developed in Brazil only in this century. The aim of the present study was to review systematically the Brazilian scientific publications related to EP and compare them to the international publications in the same period. Therefore, a systematic review of the literature was carried out on the following databases: Virtual Health Library, CAPES Theses Database, and PsycINFO. Studies containing the keyword “Evolutionary Psychology” or its correspondent version in Portuguese were used. The search was carried out considering studies available on the databases until 2010. Brazilian publications were classified by subject matter and method employed, whereas frequencies by year were computed for international studies. Although results showed a growing number of publications related to EP as a general tendency, there were few empirical studies in the area in Brazil. Non-systematic reviews of the literature and studies on general aspects of the evolutionary approach comprised the major part of Brazilian publications. The need of further empirical studies in the area in Brazil, particularly investigations of issues related to personality and psychopathology, is highlighted.

Psicologia evolucionista: uma perspectiva em expansão

A Psicologia Evolucionista (PE) é um campo teórico da Psicologia cujo objetivo é entender a natureza humana à luz da perspectiva evolucionista do neodarwinismo. Apesar de ter surgido formalmente na década de 1980, a PE começou a se popularizar no Brasil apenas neste século. O objetivo do presente trabalho foi realizar uma investigação sistemática da produção acadêmica nacional na área até o momento, contrastando-a com a produção internacional no mesmo período. Para tanto, realizou-se uma revisão sistemática de literatura nas bases de dados: Biblioteca Virtual em Saúde, Banco de Teses da CAPES e PsycINFO. Utilizou-se a palavra-chave “Psicologia Evolucionista”, e sua correspondente em inglês, e a busca abrangeu todo o período disponível nas bases até 2010. Os trabalhos nacionais foram classificados de acordo com a temática de estudo e o método empregado, enquanto os internacionais foram apenas contabilizados. Os resultados permitiram constatar que, apesar do crescimento do número de publicações tanto no Brasil como no exterior, ainda são poucos os estudos empíricos na área no país. A predominância, nos estudos nacionais, é de revisões não sistemáticas de literatura e de temas relacionados a aspectos gerais da perspectiva evolucionista. Ressalta-se a necessidade de novos estudos brasileiros, sobretudo investigações empíricas e nas áreas de personalidade e psicopatologia.(AU)

Evolutionary Psychology (EP) is a broad theoretic field within Psychology that to understand human nature from the standpoint of evolutionary perspective of neo-Darwinism. Although its emergence dates back to the 1980’s, EP has developed in Brazil only in this century. The aim of the present study was to review systematically the Brazilian scientific publications related to EP and compare them to the international publications in the same period. Therefore, a systematic review of the literature was carried out on the following databases: Virtual Health Library, CAPES Theses Database, and PsycINFO. Studies containing the keyword “Evolutionary Psychology” or its correspondent version in Portuguese were used. The search was carried out considering studies available on the databases until 2010. Brazilian publications were classified by subject matter and method employed, whereas frequencies by year were computed for international studies. Although results showed a growing number of publications related to EP as a general tendency, there were few empirical studies in the area in Brazil. Non-systematic reviews of the literature and studies on general aspects of the evolutionary approach comprised the major part of Brazilian publications. The need of further empirical studies in the area in Brazil, particularly investigations of issues related to personality and psychopathology, is highlighted.(AU)