765 research outputs found

    Humans adapt to social diversity over time

    Get PDF
    Humans have evolved cognitive processes favoring homogeneity, stability, and structure. These processes are, however, incompatible with a socially diverse world, raising wide academic and political concern about the future of modern societies. With data comprising 22 y of religious diversity worldwide, we show across multiple surveys that humans are inclined to react negatively to threats to homogeneity (i.e., changes in diversity are associated with lower self-reported quality of life, explained by a decrease in trust in others) in the short term. However, these negative outcomes are compensated in the long term by the beneficial influence of intergroup contact, which alleviates initial negative influences. This research advances knowledge that can foster peaceful coexistence in a new era defined by globalization and a socially diverse future

    Theoretical study of electric field-dependent polaron-type mobility in conjugated polymers

    Get PDF
    We have used a self-consistent quantum molecular dynamics approach to calculate the mobility of both positive and negative polaron-type carriers on solated chains of poly(p-phenylene vinylene) (PPV) and some of its derivatives and the dependence of their mobility on the applied electric field. Our results suggest that polaron-type mobility along most of these polymer chains has a clear dependence on the electric field which is quite different from the result derived for bulk PPV-based materials.Fundação para a Ciência e a Tecnologia (FCT) Programa Operacional “Ciência , Tecnologia, Inovação” – POCTI/CTM/41574/2001, CONC-REEQ/443/EEI/2001 e SFRH/BD/11231/200

    Ictiofauna Dos Enclaves De Floresta Ăşmida Nos Planaltos Da Ibiapaba E Do Araripe, Nordeste Do Brasil

    Get PDF
    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Humid highland forest enclaves are remnants of Atlantic Forest found in tablelands within the Caatinga biome (Northeastern Brazil), which emerged during interglacial periods in the Pleistocene. These ecosystems have a highly diverse and endemic fish fauna. Most earlier surveys have focused on the tableland of Borborema (Pernambuco and Paraíba States). In this study we surveyed the fish fauna of the humid forest enclaves in the tablelands of Ibiapaba and Araripe, based on samples collected in the rainy season (March and April) between 2009 and 2014. The 45 sampling points covered rivers, streams and reservoirs in five river basins belonging to three ecoregions. The species were listed according to drainage divide, and endemism was determined for each ecoregion and for the Caatinga. Our area was more species-rich (n=59) than Borborema (n=27). The samples included five introduced species and 29 species endemic to the Caatinga (49.1% of the sampled species). The distribution of Parotocinclus haroldoi was expanded to the Mid-Northeastern Caatinga ecoregion (Timonha river basin, Ceará State). Our study intends to make a significant contribution to current knowledge of the ichthyofauna in humid highland forest enclaves of semiarid Northeastern Brazil, identified as a priority in the conservation of the biodiversity in the Caatinga. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.164457463/2012-0, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico552009/2011-3, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico552086/2011-8, CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Does ethnic diversity affect well-being and allostatic load among people across neighbourhoods in England?

    Get PDF
    Modern societies are facing unprecedented changes in their ethnic composition. Increasing ethnic diversity poses critical new challenges as people interact with new cultures, norms, and values, or avoid such encounters. Heated academic and political debates focus on whether and how changes in ethnic composition affect societies and local communities. Yet, there is insufficient scientific evidence of how living in a more diverse society affects individuals' well-being and health. The aim of this study is to test the extent to which increasing neighbourhood ethnic diversity affects individuals’ subjective health and well-being and objective stress levels as measured by allostatic load. We analyse a large panel data set containing over 47,000 English respondents living in 15,545 neighbourhoods in England from the British Household Panel Survey and the UK Household Longitudinal Study, from 2004 to 2011. We match respondents to neighbourhoods and merge contextual information about levels of neighbourhood ethnic diversity and deprivation from UK Censuses, whilst controlling for background characteristics. We distinguish between short- and long-term effects of ethnic diversity on individual subjective well-being and health as well as allostatic load using a set of multilevel mixed-effects models. We make cautious causal interpretations by estimating fixed-effects models and cross-lagged panel models. We assess the robustness of our findings by replicating our analysis using alternative composite measures of diversity and allostatic load. In the short-term, increasing ethnic diversity of local areas is associated with a dip in subjective well-being, but short-term changes are not prolonged or profound enough to affect chronic stress (allostatic load). The initial negative impact of ethnic diversity on subjective well-being and health dissipates with time. In the long-term, no effects of ethnic diversity on well-being and health or chronic stress (allostatic load) are detected. Understanding the dynamic nature of the effects of ethnic diversity on individuals has critical implications for social and public health policies – issues prominent in, for example, the UK (Brexit) and the US (election of President Donald Trump). Our analysis identifies and enables the promotion of beneficial effects, while targeting the pernicious components to turn diversity into a valuable asset in a globalising world

    The Single-Particle Spectral Function of 16O^{16}{\rm O}

    Full text link
    The influence of short-range correlations on the pp-wave single-particle spectral function in 16O^{16}{\rm O} is studied as a function of energy. This influence, which is represented by the admixture of high-momentum components, is found to be small in the pp-shell quasihole wave functions. It is therefore unlikely that studies of quasihole momentum distributions using the (e,e′p)(e,e'p) reaction will reveal a significant contribution of high momentum components. Instead, high-momentum components become increasingly more dominant at higher excitation energy. The above observations are consistent with the energy distribution of high-momentum components in nuclear matter.Comment: 5 pages, RevTeX, 3 figure

    Weaving Variability into Domain Metamodels

    Get PDF
    International audienceDomain-Specific Modeling Languages (DSMLs) describe the concepts of a particular domain and their relationships, in a meta-model. From a given DSML, it is possible to describe a wide range of different models. These models often share a common base and vary on some parts. Current approaches tend to distinguish the variability language from the DSMLs themselves, implying greater learning curve for DSMLs stakeholders and a significant overhead in product line engineering of DSLs. We propose to consider variability concepts as an independent aspect to be woven into the DSML to introduce variability capabilities. In particular we detail how variability is woven and how to perform product line derivation. We validate our approach through the weaving of variability into two very different metamodels: Ecore and SmartAdapter, our aspect-oriented modelling weaver, thus adding exibility in the weaving process itself. These results emphasize how new abilities of the language can be provided by this means

    Fine-Tuning Solution for Hybrid Inflation in Dissipative Chaotic Dynamics

    Get PDF
    We study the presence of chaotic behavior in phase space in the pre-inflationary stage of hybrid inflation models. This is closely related to the problem of initial conditions associated to these inflationary type of models. We then show how an expected dissipative dynamics of fields just before the onset of inflation can solve or ease considerably the problem of initial conditions, driving naturally the system towards inflation. The chaotic behavior of the corresponding dynamical system is studied by the computation of the fractal dimension of the boundary, in phase space, separating inflationary from non-inflationary trajectories. The fractal dimension for this boundary is determined as a function of the dissipation coefficients appearing in the effective equations of motion for the fields.Comment: 10 pages, 4 eps figures (uses epsf), Revtex. Replaced with version to match one in press Physical Review

    Effects of Short Range Correlations on Ca Isotopes

    Get PDF
    The effect of Short Range Correlations (SRC) on Ca isotopes is studied using a simple phenomenological model. Theoretical expressions for the charge (proton) form factors, densities and moments of Ca nuclei are derived. The role of SRC in reproducing the empirical data for the charge density differences is examined. Their influence on the depletion of the nuclear Fermi surface is studied and the fractional occupation probabilities of the shell model orbits of Ca nuclei are calculated. The variation of SRC as function of the mass number is also discussed.Comment: 11 pages (RevTex), 6 Postscript figures available upon request at [email protected] Physical Review C in prin

    On the reliability of a simple method for scoring phenotypes to estimate heritability: A case study with pupal color in Heliconius erato phyllis, Fabricius 1775 (Lepidoptera, Nymphalidae)

    Get PDF
    In this paper, two methods for assessing the degree of melanization of pupal exuviae from the butterfly Heliconius erato phyllis, Fabricius 1775 (Lepidoptera, Nymphalidae, Heliconiini) are compared. In the first method, which was qualitative, the exuviae were classified by scoring the degree of melanization, whereas in the second method, which was quantitative, the exuviae were classified by optical density followed by analysis with appropriate software. The heritability (h2) of the degree of melanization was estimated by regression and analysis of variance. The estimates of h 2 were similar with both methods, indicating that the qualitative method could be particularly suitable for field work. The low estimates obtained for heritability may have resulted from the small sample size (n = 7-18 broods, including the parents) or from the allocation-priority hypothesis in which pupal color would be a lower priority trait compared to morphological traits and adequate larval development
    • …
    corecore