113 research outputs found
Profile and width of rough interfaces
In the context of Landau theory and its field theoretical refinements,
interfaces between coexisting phases are described by intrinsic profiles. These
intrinsic interface profiles, however, are neither directly accessible by
experiment nor by computer simulation as they are broadened by long-wavelength
capillary waves. In this paper we study the separation of the small scale
intrinsic structure from the large scale capillary wave fluctuations in the
Monte Carlo simulated three-dimensional Ising model. To this purpose, a
blocking procedure is applied, using the block size as a variable cutoff, and a
translationally invariant method to determine the interface position of
strongly fluctuating profiles on small length scales is introduced. While the
capillary wave picture is confirmed on large length scales and its limit of
validity is estimated, an intrinsic regime is, contrary to expectations, not
observed.Comment: 18 pages, 4 Postscript figures, LaTeX2e, formulation of sec.3.2
improved, 1 reference adde
Computing the Roughening Transition of Ising and Solid-On-Solid Models by BCSOS Model Matching
We study the roughening transition of the dual of the 2D XY model, of the
Discrete Gaussian model, of the Absolute Value Solid-On-Solid model and of the
interface in an Ising model on a 3D simple cubic lattice. The investigation
relies on a renormalization group finite size scaling method that was proposed
and successfully tested a few years ago. The basic idea is to match the
renormalization group flow of the interface observables with that of the
exactly solvable BCSOS model. Our estimates for the critical couplings are
, and for
the XY-model, the Discrete Gaussian model and the Absolute Value Solid-On-Solid
model, respectively. For the inverse roughening temperature of the Ising
interface we find . To the best of our knowledge,
these are the most precise estimates for these parameters published so far.Comment: 25 pages, LaTeX file, no figure
Monte Carlo Methods for Estimating Interfacial Free Energies and Line Tensions
Excess contributions to the free energy due to interfaces occur for many
problems encountered in the statistical physics of condensed matter when
coexistence between different phases is possible (e.g. wetting phenomena,
nucleation, crystal growth, etc.). This article reviews two methods to estimate
both interfacial free energies and line tensions by Monte Carlo simulations of
simple models, (e.g. the Ising model, a symmetrical binary Lennard-Jones fluid
exhibiting a miscibility gap, and a simple Lennard-Jones fluid). One method is
based on thermodynamic integration. This method is useful to study flat and
inclined interfaces for Ising lattices, allowing also the estimation of line
tensions of three-phase contact lines, when the interfaces meet walls (where
"surface fields" may act). A generalization to off-lattice systems is described
as well.
The second method is based on the sampling of the order parameter
distribution of the system throughout the two-phase coexistence region of the
model. Both the interface free energies of flat interfaces and of (spherical or
cylindrical) droplets (or bubbles) can be estimated, including also systems
with walls, where sphere-cap shaped wall-attached droplets occur. The
curvature-dependence of the interfacial free energy is discussed, and estimates
for the line tensions are compared to results from the thermodynamic
integration method. Basic limitations of all these methods are critically
discussed, and an outlook on other approaches is given
A review of applications of the Bayes factor in psychological research
The last 25 years have shown a steady increase in attention for the Bayes factor as a tool for hypothesis evaluation and model selection. The present review highlights the potential of the Bayes factor in psychological research. We discuss six types of applications: Bayesian evaluation of point null, interval, and informative hypotheses, Bayesian evidence synthesis, Bayesian variable selection and model averaging, and Bayesian evaluation of cognitive models. We elaborate what each application entails, give illustrative examples, and provide an overview of key references and software with links to other applications. The paper is concluded with a discussion of the opportunities and pitfalls of Bayes factor applications and a sketch of corresponding future research lines
Within-individual phenotypic plasticity in flowers fosters pollination niche shift
Authors thank Raquel Sánchez, Angel Caravante, Isabel Sánchez Almazo, Tatiana López
Pérez, Samuel Cantarero, María José Jorquera and Germán Fernández for helping us during
several phases of the study and Iván Rodríguez Arós for drawing the insect silhouettes. This
research is supported by grants from the Spanish Ministry of Science, Innovation and
Universities (CGL2015-71634-P, CGL2015-63827-P, CGL2017-86626-C2-1-P, CGL2017-
86626-C2-2-P, UNGR15-CE-3315, including EU FEDER funds), Junta de Andalucía (P18-
FR-3641), Xunta de Galicia (CITACA), BBVA Foundation (PR17_ECO_0021), and a
contract grant to C.A. from the former Spanish Ministry of Economy and Competitiveness
(RYC-2012-12277). This is a contribution to the Research Unit Modeling Nature, funded by
the Consejería de Economía, Conocimiento, Empresas y Universidad, and European
Regional Development Fund (ERDF), reference SOMM17/6109/UGR.Phenotypic plasticity, the ability of a genotype of producing different phenotypes when exposed to different environments, may impact ecological interactions. We study here how within-individual plasticity in Moricandia arvensis flowers modifies its pollination niche. During spring, this plant produces large, cross-shaped, UV-reflecting lilac flowers attracting mostly long-tongued large bees. However, unlike most co-occurring species, M. arvensis keeps flowering during the hot, dry summer due to its plasticity in key vegetative traits. Changes in temperature and photoperiod in summer trigger changes in gene expression and the production of small, rounded, UV-absorbing white flowers that attract a different assemblage of generalist pollinators. This shift in pollination niche potentially allows successful reproduction in harsh conditions, facilitating M. arvensis to face anthropogenic perturbations and climate change. Floral phenotypes impact interactions between plants and pollinators. Here, the authors show that Moricandia arvensis displays discrete seasonal plasticity in floral phenotype, with large, lilac flowers attracting long-tongued bees in spring and small, rounded, white flowers attracting generalist pollinators in summer.Spanish Ministry of Science, Innovation and Universities (EU FEDER funds)
CGL2015-71634-P
CGL2015-63827-P
CGL2017-86626-C2-1-P
CGL2017-86626-C2-2-P
UNGR15-CE-3315Junta de Andalucia
P18-FR-3641Xunta de GaliciaBBVA Foundation
PR17_ECO_0021Spanish Ministry of Economy and Competitiveness
RYC-2012-12277Consejeria de Economia, Conocimiento, Empresas y Universidad
SOMM17/6109/UGREuropean Union (EU)
SOMM17/6109/UG
The Cultural Transmission of Prestige and Dominance Social Rank Cues: an Experimental Simulation
This is the final version. Available from Springer via the DOI in this record.Below is the link to the dataset and preview of the experiment, and Dataset (CSV, 133KB) - process_raw_data_included.csv can be found in the Electronic Supplementary Material section Preview of the experiment: https://exetercles.eu.qualtrics.com/jfe/form/SV_071cfHiCY9qBEkB.Informal social hierarchies within small human groups are argued to be based on prestige, dominance, or a combination of the two (Henrich & Gil-White, 2001). Prestige-based hierarchies entail the ordering of individuals by the admiration and respect they receive from others due to their competence within valued domains. This type of hierarchy provides benefits for subordinates such as social learning opportunities and both private and public goods. In contrast, dominance-based hierarchies entail the ordering of individuals by their capacity to win fights, and coerce or intimidate others. This type of hierarchy produces costs in subordinates due to its aggressive and intimidating nature. Given the benefits and costs associated with these types of social hierarchies for subordinates, we hypothesised that prestige and dominance cues are better recalled and transmitted than social rank cues that do not elicit high prestige or dominance associations (i.e. medium social rank cues). Assuming that for the majority of the population who are not already at the top of the social hierarchy it is more important to avoid the costs of dominance-based hierarchies than to obtain the benefits of prestige-based hierarchies, we further hypothesised that dominance cues are better transmitted than prestige cues. We conducted a recall-based transmission chain experiment with 30 chains of four generations each (N = 120). Participants read and recalled descriptions of prestigious, dominant, and medium social rank footballers, and their recall was passed to the next participant within their chain. As predicted, we found that both prestige cues and dominance cues were better transmitted than medium social rank cues. However, we did not find support for our prediction of the better transmission of dominance cues than prestige cues. We discuss whether the results might be explained by a specific social-rank content transmission bias or by a more general emotional content transmission bias.University of Exete
The long-term consequences of retrieval demands during working memory
Although it is well known that distraction impairs immediate retrieval of items maintained in working memory (WM; e.g., during complex span tasks), some evidence suggests that these items are more likely to be recalled from episodic memory (EM) compared with items that were studied without any distraction (e.g., during simple span tasks). One account for this delayed advantage of complex span over simple span, or the McCabe effect (McCabe, Journal of Memory and Language, 58[2], 480–494, 2008), is that complex span affords covert retrieval opportunities that facilitate later retrieval from EM by cumulatively reactivating each successively presented item after distraction. This explanation focuses on the processing that occurs during presentation and maintenance of the items, but no work to date has explored whether the differential demands of immediate retrieval between simple and complex span may explain the effect. Accordingly, these experiments examined the impact of immediate retrieval demands on the McCabe effect by comparing typical immediate serial-recall instructions (i.e., recalling the words in their exact order of presentation) to immediate free-recall (Experiments 1–2) and no-recall (Experiments 2 and 3) instructions. The results suggested that the nature of retrieval may constrain the McCabe effect in some situations (Experiments 1–2), but its demands do not drive the McCabe effect given that it was observed in both serial-recall and no-recall conditions (Experiment 3). Instead, activities such as covert retrieval during the processing phase may underlie the McCabe effect, thus further evidencing the importance of processing in WM for the long-term retention of information
First Impressions of Faces of Refugees Are More Strongly Influenced by Target Cues and Perceiver Attitudes Than by Sheer Group Affiliation
Stecker J, Bürkner PC, Hellmann J, Nestler S, Back MD. First Impressions of Faces of Refugees Are More Strongly Influenced by Target Cues and Perceiver Attitudes Than by Sheer Group Affiliation. Collabra: Psychology. 2021;7(1).The importance of first impressions for various intrapersonal, social and societal outcomes is well established. First impressions towards refugees as individual members of one of the most heatedly discussed social groups in Western societies should play a key role in facilitating or impeding successful social integration. However, this issue is currently underexplored. To help understand first impressions towards refugee individuals, we conducted two studies, in which German perceivers (total N = 938) evaluated 60 (Study 1) or 48 (Study 2) male target photos of Western individuals (presented as Germans) and Middle Eastern individuals (presented as refugees). In Study 2, we included information about targets’ religious affiliations (Christian, Muslim) and religiousness (weakly religious, devout). Targets’ facial characteristics (physical attractiveness, smiling) were coded, and perceiver attitudes (right-wing authoritarianism, social dominance orientation, right-wing political ideology) were assessed. Results showed (a) no overall devaluation of refugees or Muslims, (b) strong effects of target attractiveness and smiling on evaluations across individuals of different group affiliations, (c) strong effects of perceiver attitudes towards refugees and Muslims, and (d) no interactive effects of perceiver attitudes and target cues on evaluations. It is important to note that these results should not be interpreted as any doubt about the profound experiences of discrimination and prejudices faced by minorities such as refugees. Instead, they underline the utility of an individual differences approach to better understand the circumstances under which devaluations of minoritized individuals suchs as refugees are amplified or reduced
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Intranasal Oxytocin May Improve High-Level Social Cognition in Schizophrenia, But Not Social Cognition or Neurocognition in General: A Multilevel Bayesian Meta-analysis.
While there is growing interest in the potential for intranasal oxytocin (IN-OT) to improve social cognition and neurocognition (ie, nonsocial cognition) in schizophrenia, the extant literature has been mixed. Here, we perform a Bayesian meta-analysis of the efficacy of IN-OT to improve areas of social and neurocognition in schizophrenia. A systematic search of original research publications identified randomized controlled trials (RCTs) of IN-OT as a treatment for social and neurocognitive deficits in schizophrenia for inclusion. Standardized mean differences (SMD) and corresponding variances were used in multilevel Bayesian models to obtain meta-analytic effect-size estimates. Across a total of 12 studies (N = 273), IN-OT did not improve social cognition (SMD = 0.07, 95% credible interval [CI] = [-0.06, 0.17]) or neurocognition (SMD = 0.12, 95% CI = [-0.12, 0.34]). There was moderate between study heterogeneity for social cognition outcomes (τs= 0.12). Moderator analyses revealed that IN-OT had a significantly larger effect on high-level social cognition (ie, mentalizing and theory of mind) compared to low-level social cognition (ie, social cue perception) (b = 0.19, 95% CI = [0.05, 0.33]). When restricting our analysis to outcomes for high-level social cognition, there was a significant effect of IN-OT (SMD = 0.20, 95 % CI = [0.05, 0.33]) but the effect was not robust to sensitivity analyses. The present analysis indicates that IN-OT may have selective effects on high-level social cognition, which provides a more focused target for future studies of IN-OT
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