812 research outputs found

    The Role of Extraversion, IQ and Contact in the Own-Ethnicity Face Recognition Bias.

    Get PDF
    While IQ is weakly related to the overall face recognition (Shakeshaft & Plomin, 2015), it plays a larger role in the processing of misaligned faces in the composite face task (Zhu et al., 2010). This type of stimuli are relatively novel and may reflect the involvement of intelligence in the processing of infrequently encountered faces, such as those of other-ethnicities. Extraversion is associated with increased eye contact which signifies less viewing of diagnostic features for Black faces. Using an old/new recognition paradigm, we found that IQ negatively correlated with the magnitude of the own-ethnicity bias (OEB) and that this relationship was moderated by contact with people from another ethnicity. We interpret these results in terms of IQ enhancing the ability to process novel stimuli by utilising multiple forms of coding. Extraversion was positively correlated with the OEB in White participants and negatively correlated with the OEB in Black participants suggesting that extraverts have lower attention to diagnostic facial features of Black faces, leading to poorer recognition of Black faces in both White and Black participants, thereby contributing to the relative OEB in these participants. The OEB is dependent on participant variables such as intelligence and extraversion

    A qualidade das bases de dados como factor crucial em estudos ambientais: condições de referência e tipologia com base piscícola para rios portugueses

    Get PDF
    Com base num conjunto superior a 1000 amostragens piscícolas em rios portugueses (troços vadeáveis) realizadas por diversas entidades nacionais nos últimos 10 anos, seleccionou-se um grupo de 459 locais que cumprem critérios de normalização de amostragem, procedimentos no terreno, e acuidade nas identificações taxonómicas. Estes locais representam a diversidade de condições naturais e de impactos humanos em Portugal Continental. Para caracterizar a magnitude e tipo de perturbação humana em cada local foram aplicadas 15 variáveis de pressão – ao nível do troço, segmento e bacia – classificadas de acordo com o desvio às condições naturais (de 1 para ausência de desvio, até 5 para forte degradação). Este passo envolveu um longo período de trabalho e baseou-se na análise de várias fontes de informação geográfica e documental, em inquéritos e no conhecimento do terreno. Durante as fases de selecção de locais e construção das bases de dados ambientais e biológicas, toda a informação foi sujeita a procedimentos de controle de qualidade de dados. É proposta uma metodologia para a selecção de sítios de referência; desta forma, foram incluídos neste grupo os locais com pontuação 1 ou 2 em, pelo menos, 80% das variáveis, permitindo a classificação 3 em 20% (três variáveis), excepto para a variável “abundância de indivíduos exóticos”, que obrigatoriamente correspondeu à pontuação 1 ou 2. Uma abordagem estatística multivariada suportou os dois passos seguintes: a definição da tipologia com base nas ictiocomunidades e a alocação de todos os locais num tipo. Utilizando os sítios de referência, e com base na classificação de grupos funcionais piscícolas, foram estabelecidos 6 tipos (t.): t. salmonícola da região norte; t. transição salmonícola-ciprinícola da região norte; t. ciprinícola de pequena dimensão das regiões norte interior e sul; t. ciprinícola de média dimensão da região norte; t. ciprinícola de média dimensão da região sul e t. ciprinícola da região norte litoral. A análise discriminante múltipla (ADM) suportou a tipologia piscícola, alocando correctamente 71 a 93% dos locais para os seis grupos; temperatura média em Julho, área de drenagem, altitude, precipitação média anual e uma variável categórica de enquadramento geográfico foram as variáveis retidas pelo modelo final. A ADM evidenciou elevada robustez ao classificar a maioria dos locais de não referência num dos tipos da respectiva região geográfica e ao detectar variações longitudinais das comunidades piscícolas ao longo de vários rios

    High throughput generated micro-aggregates of chondrocytes stimulate cartilage formation in vitro and in vivo

    Get PDF
    Cell-based cartilage repair strategies such as matrix-induced autologous chondrocyte implantation (MACI) could be improved by enhancing cell performance. We hypothesised that micro-aggregates of chondrocytes generated in high-throughput prior to implantation in a defect could stimulate cartilaginous matrix deposition and remodelling. To address this issue, we designed a micro-mould to enable controlled high-throughput formation of micro-aggregates. Morphology, stability, gene expression profiles and chondrogenic potential of micro-aggregates of human and bovine chondrocytes were evaluated and compared to single-cells cultured in micro-wells and in 3D after encapsulation in Dextran-Tyramine (Dex-TA) hydrogels in vitro and in vivo. We successfully formed micro-aggregates of human and bovine chondrocytes with highly controlled size, stability and viability within 24 hours. Micro-aggregates of 100 cells presented a superior balance in Collagen type I and Collagen type II gene expression over single cells and micro-aggregates of 50 and 200 cells. Matrix metalloproteinases 1, 9 and 13 mRNA levels were decreased in micro-aggregates compared to single-cells. Histological and biochemical analysis demonstrated enhanced matrix deposition in constructs seeded with micro-aggregates cultured in vitro and in vivo, compared to single-cell seeded constructs. Whole genome microarray analysis and single gene expression profiles using human chondrocytes confirmed increased expression of cartilage-related genes when chondrocytes were cultured in micro-aggregates. In conclusion, we succeeded in controlled high-throughput formation of micro-aggregates of chondrocytes. Compared to single cell-seeded constructs, seeding of constructs with micro-aggregates greatly improved neo-cartilage formation. Therefore, micro-aggregation prior to chondrocyte implantation in current MACI procedures, may effectively accelerate hyaline cartilage formation

    Phase Behavior of Bent-Core Molecules

    Full text link
    Recently, a new class of smectic liquid crystal phases (SmCP phases) characterized by the spontaneous formation of macroscopic chiral domains from achiral bent-core molecules has been discovered. We have carried out Monte Carlo simulations of a minimal hard spherocylinder dimer model to investigate the role of excluded volume interations in determining the phase behavior of bent-core materials and to probe the molecular origins of polar and chiral symmetry breaking. We present the phase diagram as a function of pressure or density and dimer opening angle ψ\psi. With decreasing ψ\psi, a transition from a nonpolar to a polar smectic phase is observed near ψ=167\psi = 167^{\circ}, and the nematic phase becomes thermodynamically unstable for ψ<135\psi < 135^{\circ}. No chiral smectic or biaxial nematic phases were found.Comment: 4 pages Revtex, 3 eps figures (included

    Thermodynamics of the Stockmayer fluid in an applied field

    Get PDF
    The thermodynamic properties of the Stockmayer fluid in an applied field are studied using theory and computer simulation. Theoretical expressions for the second and third virial coefficients are obtained in terms of the dipolar coupling constant (, measuring the strength of dipolar interactions as compared to thermal energy) and dipole-field interaction energy (α, being proportional to the applied field strength). These expressions are tested against numerical results obtained by Mayer sampling calculations. The expression for the second virial coefficient contains terms up to λ4, and is found to be accurate over realistic ranges of dipole moment and temperature, and over the entire range of the applied field strength (from zero to infinity). The corresponding expression for the third virial coefficient is truncated at λ3, and is not very accurate: higher order terms are very difficult to calculate. The virial coefficients are incorporated in to a thermodynamic theory based on a logarithmic representation of the Helmholtz free energy. This theory is designed to retain the input virial coefficients, and account for some higher order terms in the sense of a resummation. The compressibility factor is obtained from the theory and compared to results from molecular dynamics simulations with a typical value λ = 1. Despite the mathematical approximations of the virial coefficients, the theory captures the effects of the applied field very well. Finally, the vapour-liquid critical parameters are determined from the theory, and compared to published simulation results; the agreement between the theory and simulations is good. © 2015 Taylor & Francis
    corecore