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Open boundary conditions were developed for atmospheric large-eddy simulation (LES) models and implemented into the Dutch Atmospheric Large-Eddy Simulation model. The implementation was tested in a "Big Brother"-like setup, in which the simulation with open boundary conditions was forced by an identical control simulation with periodic boundary conditions. The results show that the open boundary implementation has minimal influence on the solution. Both the mean state and the turbulent structures are close to the control simulation, and disturbances at the in- and outflow boundaries are negligible. To emulate a setup in which the LES is coupled to a coarser model, the influence of coarse boundary input was tested by smoothing the output of the periodic control simulation both temporally and spatially before feeding it as input to the simulation with open boundary conditions. When smoothing is applied over larger spatial and longer temporal scales, disturbances start to form at the inflow boundary and an area exists where turbulence needs to develop. Adding synthetic turbulence to the smoothed input reduces the size of this area and the magnitude of the disturbances. [ABSTRACT FROM AUTHOR]

We introduce a mathematical model of cultural evolution to study cultural traits that shape how individuals exchange information. Current theory focuses on traits that influence the reception of information (receiver traits), such as evaluating whether information represents the majority or stems from a trusted source. Our model shifts the focus from the receiver to the sender of cultural information and emphasizes the role of sender traits, such as communicability or persuasiveness. Here, we show that sender traits are probably a stronger driving force in cultural evolution than receiver traits. While receiver traits evolve to curb cultural transmission, sender traits can amplify it and fuel the self-organization of systems of mutually supporting cultural traits, including traits that cannot be maintained on their own. Such systems can reach arbitrary complexity, potentially explaining uniquely human practical and mental skills, goals, knowledge and creativity, independent of innate factors. Our model incorporates social and individual learning throughout the lifespan, thus connecting cultural evolutionary theory with developmental psychology. This approach provides fresh insights into the trait-individual duality, that is, how cultural transmission of single traits is influenced by individuals, who are each represented as an acquired system of cultural traits. [ABSTRACT FROM AUTHOR]

Small shallow cumulus clouds (<1 km) over the tropical oceans appear to possess the ability to self‐organize into mesoscale (10–100 km) patterns. To better understand the processes leading to such self‐organized convection, we present Cloud Botany, an ensemble of 103 large‐eddy simulations on domains of 150 km, produced by the Dutch Atmospheric Large Eddy Simulation model on supercomputer Fugaku. Each simulation is run in an idealized, fixed, larger‐scale environment, controlled by six free parameters. We vary these over characteristic ranges for the winter trades, including parameter combinations observed during the EUREC4A (Elucidating the role of clouds–circulation coupling in climate) field campaign. In contrast to simulation setups striving for maximum realism, Cloud Botany provides a platform for studying idealized, and therefore more clearly interpretable causal relationships between conditions in the larger‐scale environment and patterns in mesoscale, self‐organized shallow convection. We find that any simulation that supports cumulus clouds eventually develops mesoscale patterns in their cloud fields. We also find a rich variety in these patterns as our control parameters change, including cold pools lined by cloudy arcs, bands of cross‐wind clouds and aggregated patches, sometimes topped by thin anvils. Many of these features are similar to cloud patterns found in nature. The published data set consists of raw simulation output on full 3D grids and 2D cross‐sections, as well as post‐processed quantities aggregated over the vertical (2D), horizontal (1D) and all spatial dimensions (time‐series). The data set is directly accessible from Python through the use of the EUREC4A intake catalog. Plain Language Summary: The organization of shallow cumulus clouds over the tropical ocean has recently received a lot of attention. This type of organization is potentially important for how the clouds are affected by a changing climate and also for how they modulate further warming. We present a collection of 103 detailed simulations of shallow cumulus clouds in idealized atmospheric environments. These environments are described by six parameters, and our collection is formed by systematically simulating different parameter combinations. This way an ensemble is created that spans up a multidimensional phase space of environmental conditions typical for the wintertime subtropical Atlantic Ocean. This approach allows us to form a picture of how the environmental conditions relate to the cloud organization that develops in the simulations. At a glance, most simulations evolve similarly: They quickly form small cumulus clouds, which then grow in size and organize into patterns. Often this leads to rainfall, which then causes further heterogeneity and pattern formation. The data is openly available online, and will serve future studies of cumulus clouds, their organization, and how they interact with the climate. Key Points: We present Cloud Botany, an ensemble of idealized large‐eddy simulations of the winter trade wind regions, controlled by six varied parametersThe parameter ranges are chosen to match the climatology of the trade wind regionThe simulations show a variety of cloud organization patterns: small cumulus, stripes, cold pools, cloud arcs, and anvils [ABSTRACT FROM AUTHOR]

Open boundary conditions were developed for atmospheric large eddy simulation (LES) models and implemented into the Dutch Atmospheric Large Eddy simulation model. The implementation was tested in a "Big Brother"-like setup, in which the simulation with open boundary conditions was forced by an identical control simulation with periodic boundary conditions. The results show that the open boundary implementation has minimal influence on the solution. Both the mean 5 state and the turbulent structures are close to the control simulation and disturbances at the in- and outflow boundaries are negligible. To emulate a setup in which the LES is coupled to a coarser model, the influence of coarse boundary input was tested by smoothing the output of the periodic control simulation both temporally and spatially before feeding it as input to the simulation with open boundary conditions. The results show that when the ratio between input and model resolution increases, disturbances start to form at the inflow boundary and an area exists where turbulence needs to develop. Adding synthetic 10 turbulence to the smoothed input reduces the size of this area and the magnitude of the disturbances. [ABSTRACT FROM AUTHOR]

In 1827, an Indian juggler named Mooty Madua Samme converted to Christianity in Stockholm, Sweden. This historical event got much attention in the press at the time – as did his succeeding marriage to a Swedish woman named Erica – and was celebrated as a victory for the Evangelical Lutheran faith. Later, in the 1840s, a narrative depicting the event spread via a travelogue by Xavier Marmier, which was translated and mediated through the Swedish press, and reacted to by Samme's priest; in the 1850s, Samme's name surfaced again – now in context of the contemporary freedom of religion debates in Sweden. In this article, we explore Samme's baptism (and interrelatedly, his marriage) by looking at newspaper mediations of the event and the related narratives. Seen from a microhistorical perspective, we show how Samme's conversion and religious otherness was utilised in contemporary religious and political discussions, and we argue that the event and narratives surrounding the baptism can augment our understanding of the Swedish nineteenth century religio‐cultural landscape in which he was situated. [ABSTRACT FROM AUTHOR]

A new generation of operational atmospheric models operating at horizontal resolutions in the range 200 m ∼ 2 km is becoming increasingly popular for operational use in numerical weather prediction and climate applications. Such grid spacings are becoming sufficiently fine to resolve a fraction of the turbulent transports. Here we analyze Large‐eddy simulation results of a convective boundary layer obtained by coarsening horizontal grid spacings up to 800 m. The aim is to explore the dependency of the mean state and turbulent fluxes on the grid resolution. Both isotropic and anisotropic eddy diffusion approaches are evaluated, where in the latter case the horizontal and vertical eddy diffusivities differ in accord with their horizontal and vertical grid spacings. For coarsening horizontal grid sizes entrainment at the top of the boundary layer tends to get slightly enhanced for isotropic diffusion, whereas for the anisotropic diffusion approach the vertically well‐mixed boundary‐layer structure becomes severely degraded. An analysis of the energy spectrum shows that anisotropic diffusion causes relatively more dissipation of variance at smaller length scales. This leads, in turn, to a shift of spectral energy toward larger length scales that also becomes apparent from a rather different kind of spatial organization of convection. The present study therefore suggests that details with regards to the representation of processes at small scales might impact the organization at length scales much larger than the smallest scales that can be resolved by the model. Plain Language Summary: A new generation of operational atmospheric models operating at horizontal resolutions in the range 200 m ∼ 2 km is becoming increasingly popular for operational use in numerical weather prediction and climate applications. Owing to ever increasing computational power their grid spacings are nowadays becoming sufficiently fine to allow for resolving a fraction of the turbulent transports. However, these types of models are operated with grid spacings that are much larger in the horizontal directions than in the vertical direction. In the present study we explore the extent to which the spatial organization of turbulence structures is affected by the size of the horizontal grid spacing. This question is addressed by means of large‐eddy simulation, which is an established modeling technique that has been designed specifically to resolve the dominant turbulent eddies at a high spatial resolution. It is found that differences in the way how turbulence at scales smaller than the grid spacing is calculated can have an effect on the organization of turbulent structures at much larger spatial scales. Key Points: A grid anisotropy factor is introduced to efficiently switch from an isotropic to an anisotropic eddy diffusion approach for large‐eddy simulation modelsThe organization of clear boundary‐layer convection depends on the horizontal grid spacings, most notably for the anisotropic eddy diffusion approachReduced variances at the smallest length scales may be compensated by opposite increases at larger length scales [ABSTRACT FROM AUTHOR]

This article examines the materiality of the Ghost Dance shirt – ógle wakȟáŋ kiŋ – among the Lakota, and its associated symbols and functions. By cross-referencing sources on the Ghost Dance to sources on traditional Lakota belief and ritual, it is shown that the practice of interrituality – the use of established ritual elements and acts in novel contexts – enabled traditional ritual dynamics and ontological understandings to be actualized and materialized in the Ghost Dance. This gave it performative powers and a sense of cultural familiarity with which participants could navigate a turbulent period with recognizable ritual elements. Considering the primacy of visions, concepts such as wakȟáŋ, wašíčuŋ, tȟúŋ, and wótȟawe, protective designs, and ritual processes, the article problematizes a tradition-innovation dichotomy, suggesting instead that ritual materiality mediated between the two. Likewise, it is argued that the protective nature of the shirts was primarily existential and spiritual rather than exhibitions of militarism. [ABSTRACT FROM AUTHOR]

In atmospheric modeling, superparameterization (SP) has gained popularity as a technique to improve cloud and convection representations in large‐scale models by coupling them locally to cloud‐resolving models. We show how the different representations of cloud water in the local and the global models in SP lead to a suppression of cloud advection and ultimately to a systematic underrepresentation of the cloud amount in the large‐scale model. We demonstrate this phenomenon in a regional SP experiment with the global model OpenIFS coupled to the local model Dutch Atmospheric Large Eddy Simulation, as well as in an idealized setup, where the large‐scale model is replaced by a simple advection scheme. As a starting point for mitigating the problem of suppressed cloud advection, we propose a scheme where the spatial variability of the local model's total water content is enhanced in order to match the global model's cloud condensate amount. The proposed scheme enhances the cloud condensate amount in the test cases, however a large discrepancy remains, caused by rapid dissipation of the clouds added by the proposed scheme. Plain Language Summary: In this article, we investigate a technique called superparameterization (SP) for improving how global weather and climate models represent clouds and convection. In current operational global weather and climate models, the resolution is limited to 10–100 km by computational resources. This is not sufficient to resolve cloud and convective processes. The effect of these processes must then be approximated by so‐called parameterizations. SP uses another, local atmospheric model with a higher resolution, nested inside the columns of the global model, to evaluate the effects of clouds and convection. By analyzing results from a superparameterized simulation, we show that SP as it is generally implemented suppresses advection of existing clouds from one grid column to another in the global model, leading to a severe underestimation of the amount of shallow clouds. The suppression occurs because the global and local models represent clouds in different ways, and the commonly used SP scheme does not communicate the full cloud information from the global model to the local one. Adding such a coupling of the cloud information to the SP scheme partially improves the advection of clouds. The remaining discrepancies indicate that there are still missing processes in the superparameterized representation of boundary layer clouds. Key Points: Superparameterization (SP) in weather and climate models is used to improve the representation of cloudsWe show that SP suppresses the transport of cloudsA scheme for controlling the humidity variation partially improves cloud representation in superparameterized models [ABSTRACT FROM AUTHOR]

Cultural evolution theory has long been inspired by evolutionary biology. Conceptual analogies between biological and cultural evolution have led to the adoption of a range of formal theoretical approaches from population dynamics and genetics. However, this has resulted in a research programme with a strong focus on cultural transmission. Here, we contrast biological with cultural evolution, and highlight aspects of cultural evolution that have not received sufficient attention previously. We outline possible implications for evolutionary dynamics and argue that not taking them into account will limit our understanding of cultural systems. We propose 12 key questions for future research, among which are calls to improve our understanding of the combinatorial properties of cultural innovation, and the role of development and life history in cultural dynamics. Finally, we discuss how this vibrant research field can make progress by embracing its multidisciplinary nature. This article is part of the theme issue 'Foundations of cultural evolution'. [ABSTRACT FROM AUTHOR]

A specific goal of the field of cultural evolution is to understand how processes of transmission and selection at the individual level lead to population-wide patterns of cultural diversity and change. Models of cultural evolution have typically assumed that traits are independent of one another and essentially exchangeable. But culture has a structure: traits bear relationships to one another that affect the transmission and selection process itself. Here, we introduce a modelling framework to explore the effect of interdependencies on the process of learning. Through simulations, we find that introducing a simple structure changes the cultural dynamics. Based on a basic filtering mechanism for parsing trait relationships, more elaborate cultural filters emerge. In a mostly incompatible cultural domain of traits, these filters organize culture into mostly (but not fully) consistent and stable systems. Incompatible domains produce small homogeneous cultures, while more compatibility increases size, diversity and group divergence. When individuals copy based on a trait's features (here, its compatibility relationships), they produce more homogeneous cultures than when they copy based on the agent carrying the cultural trait. We discuss the implications of considering cultural systems and filters in the dynamics of cultural change. This article is part of the theme issue 'Foundations of cultural evolution'. [ABSTRACT FROM AUTHOR]

In this article, we explore the fruitfulness of seeing allosemitism as an aspect of cosmisation. We explore possible tropes such as creating order from chaos, embracing Christian identity and supersessionism, and legitimising the Bible’s truth claims. Drawing from the Swedish press of the period 1770–1900, allosemitism and cosmisation are explored through the lens of three tenacious myths, all of which date back centuries: Blood Libel, the Wandering Jew and Israelite Indians. The ‘Jew’ as the Other is frequent in previous research. The combination of allosemitism and cosmisation gives us another way to explain the Othering of the ‘Jew’: expressions of allosemitism in a world-creating process. [ABSTRACT FROM AUTHOR]

In this study, we investigate uncertainties in a large eddy simulation of the atmosphere, employing modern uncertainty quantification methods that have hardly been used yet in this context. When analysing the uncertainty of model results, one can distinguish between uncertainty related to physical parameters whose values are not exactly known, and uncertainty related to modelling choices such as the selection of numerical discretization methods, of the spatial domain size and resolution, and the use of different model formulations. While the former kind is commonly studied e.g. with forward uncertainty propagation, we explore the use of such techniques to also assess the latter kind. From a climate modelling perspective, uncertainties in the convective response and cloud formation are of particular interest, since these affect the cloud-climate feedback, one of the dominant sources of uncertainty in current climate models. Therefore we analyse the DALES model in the RICO case, a well-studied convection benchmark. We use the VECMA toolkit for uncertainty propagation, assessing uncertainties stemming from physical parameters as well as from modelling choices. We find substantial uncertainties due to small random initial state perturbations, and that the choice of advection scheme is the most influential of the modelling choices we assessed. This article is part of the theme issue 'Reliability and reproducibility in computational science: implementing verification, validation and uncertainty quantification in silico'. [ABSTRACT FROM AUTHOR]

Much is known about Swedes in America, but little is known about the portrayals of Native Americans in Swedish-American newspapers. Considering their centrality in Swedish American settler communities, this article explores newspaper portrayals as processes of boundary construction. By utilizing the Eliadean concept of cosmisation it is shown how and argued that newspapers served as canvases for Swedes to articulate, contest, and negotiate the boundaries of valorized social orders. Therein, religion, civilization, and race were predominant themes. Processes of cosmisation also highlight mythological motifs manifested in the newspapers. Specifically, settlers and missionaries were mediated as culture heroes and initiators of cosmisation and cosmogony. [ABSTRACT FROM AUTHOR]

The Radiative‐Convective Equilibrium Model Intercomparison Project (RCEMIP) is an intercomparison of multiple types of numerical models configured in radiative‐convective equilibrium (RCE). RCE is an idealization of the tropical atmosphere that has long been used to study basic questions in climate science. Here, we employ RCE to investigate the role that clouds and convective activity play in determining cloud feedbacks, climate sensitivity, the state of convective aggregation, and the equilibrium climate. RCEMIP is unique among intercomparisons in its inclusion of a wide range of model types, including atmospheric general circulation models (GCMs), single column models (SCMs), cloud‐resolving models (CRMs), large eddy simulations (LES), and global cloud‐resolving models (GCRMs). The first results are presented from the RCEMIP ensemble of more than 30 models. While there are large differences across the RCEMIP ensemble in the representation of mean profiles of temperature, humidity, and cloudiness, in a majority of models anvil clouds rise, warm, and decrease in area coverage in response to an increase in sea surface temperature (SST). Nearly all models exhibit self‐aggregation in large domains and agree that self‐aggregation acts to dry and warm the troposphere, reduce high cloudiness, and increase cooling to space. The degree of self‐aggregation exhibits no clear tendency with warming. There is a wide range of climate sensitivities, but models with parameterized convection tend to have lower climate sensitivities than models with explicit convection. In models with parameterized convection, aggregated simulations have lower climate sensitivities than unaggregated simulations. Plain Language Summary: This study investigates tropical clouds and climate using results from more than 30 different numerical models set up in a simplified framework. The data set of model simulations is unique in that it includes a wide range of model types configured in a consistent manner. We address some of the biggest open questions in climate science, including how cloud properties change with warming and the role that the tendency of clouds to form clusters plays in determining the average climate and how climate changes. While there are large differences in how the different models simulate average temperature, humidity, and cloudiness, in a majority of models, the amount of high clouds decreases as climate warms. Nearly all models simulate a tendency for clouds to cluster together. There is agreement that when the clouds are clustered, the atmosphere is drier with fewer clouds overall. We do not find a conclusive result for how cloud clustering changes as the climate warms. Key Points: Temperature, humidity, and clouds in radiative‐convective equilibrium vary substantially across modelsModels agree that self‐aggregation dries the atmosphere and reduces high cloudinessThere is no consistency in how self‐aggregation depends on warming [ABSTRACT FROM AUTHOR]

We suggest a new method for detecting patterns of social clustering based on choice data. The method compares similar subjects within and between cohorts and thereby allows us to isolate the effect of peer influence from that of exogenous factors. Using this method on Norwegian register data, we address the question of whether students tend to cluster socially based on similar background. We find that common background correlates with making the same choices of curricular tracks, and that both exogenous preferences and peer influence matter. This applies to immigrant students from the same country, and, to some extent, to descendants of immigrants, but not to students from culturally similar countries. There are also small effects related to parents' education and income. [ABSTRACT FROM AUTHOR]

Based on the track geometry car recordings performed from 1999 to 2016 on a section of the Swedish heavy haul line Malmbanan, the vertical track geometry degradation is analysed for wavelengths in the interval 1-25 m. The upper layer of the subgrade on parts of the rail section is peat (depths of up to 2 m), while it is moraine on others leading to a significant longitudinal variation in substructure stiffness. The degradation rates of irregularities in the longitudinal level and the influence of track maintenance (tamping) on the track geometry are studied. In parallel, a method for continuous measurement of track vertical stiffness along the line, allowing for the detection of track sections with poor support conditions, is described and demonstrated. Synchronised measurements of the longitudinal level and the track vertical stiffness are evaluated to determine whether there is a correlation between a high stiffness gradient due to variations in substructure stiffness and a high growth rate of local track geometry irregularities. It is shown that recurrent severe local track geometry irregularities often occur on track sections where there is a combination of a low magnitude and a high gradient in the substructure stiffness. In such cases, tamping may not be a cost-efficient long-term solution to the problem. Instead, upgrading of ballast and subgrade layers should be considered as an option. It is concluded that measurement of track vertical stiffness is an efficient method for the maintenance planning of a more robust railway track, which also minimises the life cycle cost and environmental footprint. [ABSTRACT FROM AUTHOR]

As a computationally attractive alternative for global large eddy simulations (LESs), we investigate the possibility of using comprehensive three‐dimensional LESs as a superparameterization that can replace all traditional parameterizations of atmospheric processes that are currently used in global models. We present the technical design for a replacement of the parameterization for clouds, convection, and turbulence of the global atmospheric model of the European Centre for Medium‐Range Weather Forecasts by the Dutch Atmospheric Large Eddy Simulation model. The model coupling consists of bidirectional data exchange between the global model and the high‐resolution LES models embedded within the columns of the global model. Our setup allows for selective superparameterization, that is, for applying superparameterization in local regions selected by the user, while keeping the standard parameterization of the global model intact outside this region. Computationally, this setup can result in major geographic load imbalance, because of the large difference in computational load between superparameterized and nonsuperparameterized model columns. To resolve this issue, we use a modular design where the local and global models are kept as distinct model codes and organize the model coupling such that all the local models run in parallel, separate from the global model. First simulation results, employing this design, demonstrate the potential of our approach. Key Points: We present an efficient implementation of a large eddy simulation (LES)‐based superparameterization in a global circulation modelSuperparameterization can be enabled for grid points in a selected areaThe initial results of an LES‐based superparameterized simulation are evaluated and found promising [ABSTRACT FROM AUTHOR]

There is widespread segregation between workplaces along ethnic lines. We expand upon previous research on segregation and social influence by testing the effect of the latter on personal diversity preferences, specifically in employees' selection into hypothetical workplaces. In a survey study with 364 European American respondents in three waves, participants complied with social consensus preferences for either more or less workplace diversity. The new preference was sufficiently internalized to be retained largely unaltered a week later. Simulations suggest a self-reinforcing effect, where accurate social consensus information may be sufficient to change preferences. Given that initial choices were polarized, perceived social consensus can vary highly between people in society, and influencing this perception may feed back into greater acceptance of minorities. [ABSTRACT FROM AUTHOR]

Summary: Morphometrics, the assignment of quantities to biological shapes, is a powerful tool to address taxonomic, evolutionary, functional and developmental questions. We propose a novel method for shape quantification of complex modular architecture in thalloid plants, whose extremely reduced morphologies, combined with the lack of a formal framework for thallus description, have long rendered taxonomic and evolutionary studies extremely challenging. Using graph theory, thalli are described as hierarchical series of nodes and edges, allowing for accurate, homologous and repeatable measurements of widths, lengths and angles. The computer program MorphoSnake was developed to extract the skeleton and contours of a thallus and automatically acquire, at each level of organization, width, length, angle and sinuosity measurements. Through the quantification of leaf architecture in Hymenophyllum ferns (Polypodiopsida) and a fully worked example of integrative taxonomy in the taxonomically challenging thalloid liverwort genus Riccardia, we show that MorphoSnake is applicable to all ramified plants. This new possibility of acquiring large numbers of quantitative traits in plants with complex modular architectures opens new perspectives of applications, from the development of rapid species identification tools to evolutionary analyses of adaptive plasticity. [ABSTRACT FROM AUTHOR]

What determines countries' successful transition to democracy? This article explores the impact of granting civil rights in authoritarian regimes and especially the gendered aspect of this process. It argues that both men's and women's liberal rights are essential conditions for democratisation to take place: providing both women and men rights reduces an inequality that affects half of the population, thus increasing the costs of repression and enabling the formation of women's organising - historically important to spark protests in initial phases of democratisation. This argument is tested empirically using data that cover 173 countries over the years 1900-2012 and contain more nuanced measures than commonly used. Through novel sequence analysis methods, the results suggest that in order to gain electoral democracy a country first needs to furnish civil liberties to both women and men. [ABSTRACT FROM AUTHOR]

Background: Many organisms such as plants can be characterized as complex-shaped branching forms. The morphological quantification of the forms is a support for a number of areas such as the effects of environmental factors and species discrimination. To date, there is no software package suitable for our dataset representing the forms. We therefore formulate methods for extracting morphological measurements from images of the forms. Results: As a case study we analyze two-dimensional images of samples from four groups belonging to three species of thalloid liverworts, genus Riccardia. The images are pre-processed and converted into binary images, then skeletonized to obtain a skeleton image, in which features such as junctions and terminals are detected. Morphological measurements known to characterize and discriminate the species in the samples such as junction thickness, branch thickness, terminal thickness, branch length, branch angle, and terminal spacing are then quantified. The measurements are used to distinguish among the four groups of Riccardia and also between the two groups of Riccardia amazonica collected in different locations, Africa and South America. Canonical discriminant analysis results show that those measurements are able to discriminate among the four groups. Additionally, it is able to discriminate R. amazonica collected in Africa from those collected in South America. Conclusions: This paper presents general automated methods implemented in our software for quantifying two-dimensional images of complex branching forms. The methods are used to compute a series of morphological measurements. We found significant results to distinguish Riccardia species by using the measurements. The methods are also applicable for analyzing other branching organisms. Our software is freely available under the GNU GPL. [ABSTRACT FROM AUTHOR]

A strategy activated in one task may be transferred to subsequent tasks and prevent activation of other strategies that would otherwise come to mind, a mechanism referred to as procedural priming. In a novel application of procedural priming we show that it can make or break cognitive illusions. Our test case is the 1/k illusion, which is based on the same unwarranted mathematical shortcut as the MPG illusion and the time-saving bias. The task is to estimate distances between values of fractions on the form 1/k. Most people given this task intuitively base their estimates on the distances between the denominators (i.e., the reciprocals of the fractions), which may yield very poor estimations of the true distances between the fractions. As expected, the tendency to fall for this illusion is related to cognitive style (Study 1). In order to apply procedural priming we constructed versions of the task in which the illusion is weak, in the sense that most people do not fall for it anymore. We then gave participants both "strong illusion" and "weak illusion" versions of the task (Studies 2 and 3). Participants who first did the task in the weak illusion version would often persist with the correct strategy even in the strong illusion version, thus breaking the otherwise strong illusion in the latter task. Conversely, participants who took the strong illusion version first would then often fall for the illusion even in the weak illusion version, thus strengthening the otherwise weak illusion in the latter task. [ABSTRACT FROM AUTHOR]

Determinants of cooperation include ingroup vs. outgroup membership, and individual traits, such as prosociality and trust. We investigated whether these factors can be overridden by beliefs about people’s trust. We manipulated the information players received about each other’s level of general trust, “high” or “low”. These levels were either measured () or just arbitrarily assigned labels (). Players’ choices whether to cooperate or defect in a stag hunt (or an assurance game)—where it is mutually beneficial to cooperate, but costly if the partner should fail to do so—were strongly predicted by what they were told about the other player’s trust label, as well as by what they were told that the other player was told about their own label. Our findings demonstrate the importance for cooperation in a risky coordination game of both first- and second-order beliefs about how much people trust each other. This supports the idea that institutions can influence cooperation simply by influencing beliefs. [ABSTRACT FROM AUTHOR]

Background: The spatial distribution of many genes has been visualized during the embryonic development in the starlet sea anemone Nematostella vectensis in the last decade. In situ hybridization images are available in the Kahi Kai gene expression database, and a method has been developed to quantify spatial gene expression patterns of N. vectensis. In this paper, gene expression quantification is performed on a wide range of gene expression patterns from this database and descriptions of observed expression domains are stored in a separate database for further analysis. Methods: Spatial gene expression from suitable in situ hybridization images has been quantified with the GenExp program. A correlation analysis has been performed on the resulting numerical gene expression profiles for each stage. Based on the correlated clusters of spatial gene expression and detailed descriptions of gene expression domains, various mechanisms for developmental gene expression are proposed. Results: In the blastula and gastrula stages of development in N. vectensis, its continuous sheet of cells is partitioned into correlating gene expression domains. During progressing development, these regions likely correspond to different fates. A statistical analysis shows that genes generally remain expressed during the planula stages in those major regions that they occupy at the end of gastrulation. Discussion: Observed shifts in gene expression domain boundaries suggest that elongation in the planula stage mainly occurs in the vegetal ring under the influence of the gene Rx. The secondary body axis in N. vectensis is proposed to be determined at the mid blastula transition. Conclusions: Early gene expression domains in N. vectensis appear to maintain a positional order along the primary body axis. Early determination in N. vectensis occurs in two stages: expression in broad circles and rings in the blastula is consolidated during gastrulation, and more complex expression patterns appear in the planula within these broad regions. Quantification and comparison of gene expression patterns across a database can generate hypotheses about collective cell movements before these movements are measured directly. [ABSTRACT FROM AUTHOR]

There is an increasing wealth of models trying to explain the evolution of group discrimination and an ingroup bias. This paper sets out to systematically investigate the most fundamental assumption in these models: in what kind of situations do the interactions take place? What strategic structures – games – support the evolution of an ingroup bias? More specifically, the aim here is to find the prerequisites for when a bias also with respect to minimal groups – arbitrarily defined groups void of group-specific qualities – is selected for, and which cannot be ascribed to kin selection. Through analyses and simulations of minimal models of two-person games, this paper indicates that only some games are conducive to the evolution of ingroup favouritism. In particular, this class does not contain the prisoners׳ dilemma, but it does contain anti-co-ordination and co-ordination games. Contrasting to the prisoners׳ dilemma, these are games where it is not a matter of whether to behave altruistically, but rather one of predicting what the other person will be doing, and where I would benefit from you knowing my intentions. In anti-co-ordination games, on average, not only will agents discriminate between groups, but also in such a way that their choices maximise the sum of the available payoffs towards the ingroup more often than towards the outgroup. And in co-ordination games, even if agents do manage to co-ordinate with the whole population, they are more likely to co-ordinate on the socially optimal equilibrium within their group. Simulations show that this occurs most often in games where there is a component of risk-taking, and thus trust, involved. A typical such game is the stag hunt or assurance game. [ABSTRACT FROM AUTHOR]

This paper presents a computer simulation of the genesis of Mauritian Creole. The input consists of detailed demographic data and typological information on Mauritian as well as the languages which contributed to its birth. The simulation is deliberately a simplistic one – the idea is to have as few potentially controversial assumptions as possible built into the model, and add additional parameters only to the extent that its output differs from the real-world result. As it turns out, the model generates a language which is highly similar to Mauritian as it is spoken today, and thus, very little “tweaking” seems necessary. Most notably, the model produces the desired result without the postulation of targeted language acquisition, and while one cannot conclude that this was not a part of the creolisation process, our simulation suggests that it is not a necessary assumption. [ABSTRACT FROM PUBLISHER]

We introduce negative externalities in the form of ill will among the players of the classic two-sided assignment game of Shapley and Shubik, by letting each player's utility be negatively correlated with the payoff of all the players in his group. The new game is very complex, but under a certain assumption of bounded rationality we derive a straightforward notion of stable outcomes as certain conjectural equilibria. We prove that several well-known properties of the set of stable outcomes in the assignment game carry over to this new game. [ABSTRACT FROM AUTHOR]

Transitions to democracy are most often considered the outcome of historical modernization processes. Socio-economic changes, such as increases in per capita GNP, education levels, urbanization and communication, have traditionally been found to be correlates or 'requisites' of democratic reform. However, transition times and the number of reform steps have not been studied comprehensively. Here we show that historically, transitions to democracy have mainly occurred through rapid leaps rather than slow and incremental transition steps, with a median time from autocracy to democracy of 2.4 years, and overnight in the reverse direction. Our results show that autocracy and democracy have acted as peaks in an evolutionary landscape of possible modes of institutional arrangements. Only scarcely have there been slow incremental transitions. We discuss our results in relation to the application of phylogenetic comparative methods in cultural evolution and point out that the evolving unit in this system is the institutional arrangement, not the individual country which is instead better regarded as the 'host' for the political system. [ABSTRACT FROM AUTHOR]

The paper investigates temporary layoffs in the Swedish labour market. Previous reports of few temporary layoffs are rejected. About 45 percent of unemployed people who found a job returned to a previous employer. As a stock measure, 10 percent of the unemployed are on temporary layoff. Using new job and recall as distinct exits in a competing risks model, one cannot reject a horizontal duration dependence for new jobs, while the recall hazard shows a strong, negative duration dependence. Clearer predictions of the effect of education on job probabilities are also found. Further, the results probably have implications for the interpretation of several policy parameters, including labour market programme outcomes. [ABSTRACT FROM AUTHOR]

The working principles of thin film organic memory devices remain debated and tunability has been less presented. We show that the nanostructure of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and polystyrene (PS) allows facile tuning of switching behavior for low PCBM concentrations upon annealing above the glass transition temperature of PS. By increasing the PCBM concentration from 2 to 6 wt %, the switching voltage from off to on state during the first voltage sweep systematically decreases. In subsequent voltage sweeps negative differential resistance effect is observed. Above ca. 7 wt %, chains of PCBM clusters couple the electrodes, which leads to Ohmic behavior. [ABSTRACT FROM AUTHOR]

We present the superparametrization (SP) of the ECMWF weather forecast model OpenIFS, by three-dimensional, high-resolution, large eddy simulations. Within a selected region, our setup replaces the global model parametrizations of boundary layer turbulence, cloud physics and convection processes with tendencies derived from the vertical profiles of instances of the Dutch Atmospheric Large Eddy Simulation (DALES). Vice versa, these LES models are being forced towards the corresponding local vertical profiles of the global model. We consistently combine the sequential physics scheme of OpenIFS with the Grabowski SP scheme and achieve concurrent execution of the independent DALES models on separate CPU's. The superparametrized region can be chosen to match the available compute resources, and we have implemented mean-state acceleration to speed up the LES time stepping. The coupling of the components has been implemented in a Python software layer using the OMUSE multi-scale physics framework. As a result, our setup yields a cloud-resolving NWP model that displays emergent mesoscale cloud organization and has the potential to improve the representation of clouds and convection processes in OpenIFS. It allows us to study the interaction of boundary layer physics with the large scale dynamics, to assess cloud and convection parametrization in the ECMWF model and eventually to improve our understanding of cloud feedback in climate models. [ABSTRACT FROM AUTHOR]

Ethnocentrism refers to the tendency to behave differently towards strangers based only on whether they belong to the ingroup or the outgroup. It is a widespread phenomenon that can be triggered by arbitrary cues, but the origins of which are not clearly understood. In a recent simulation model by Hammond and Axelrod, an ingroup bias evolves in the prisoners' dilemma game. However, it will be argued here that the model does little to advance our understanding of ethnocentrism. The model assumes a spatial structure in which agents interact only with their immediate neighbourhood, populated mostly by clones, and the marker becomes an approximate cue of whether the partner is one. It will be shown that agents with an ingroup bias are successful compared to unconditional co-operators since they only exclude non-clones, but are outcompeted by less error-prone kin identifiers. Thus, the results of the simulations can be explained by a simple form of kin selection. These findings illustrate how spatial assumptions can alter a model to the extent that it no longer describes the phenomenon under study. [ABSTRACT FROM AUTHOR]

Understanding genetic interactions during early development of a given organism, is the first step toward unveiling gene regulatory networks (GRNs) that govern a biological process of interest. Predicting such interactions from large expression datasets by performing targeted knock-down/knock-out approaches is a challenging task. We use the currently available expression datasets ( in situ hybridization images & qPCR time series) for a basal anthozoan the sea anemone N. vectensis to construct continuous spatiotemporal gene expression patterns during its early development. Moreover, by combining cluster results from each dataset we develop a method that provides testable hypotheses about potential genetic interactions. We show that the analysis of spatial gene expression patterns reveals functional regions of the embryo during the gastrulation. The clustering results from qPCR time series unveils significant temporal events and highlights genes potentially involved in N. vectensis gastrulation. Furthermore, we introduce a method for merging the clustering results from spatial and temporal datasets by which we can group genes that are expressed in the same region and at the time. We demonstrate that the merged clusters can be used to identify GRN interactions involved in various processes and to predict possible activators or repressors of any gene in the dataset. Finally, we validate our methods and results by predicting the repressor effect of NvErg on NvBra in the central domain during the gastrulation that has recently been confirmed by functional analysis. [ABSTRACT FROM AUTHOR]