RESUMO
Bodily postures are essential to correctly comprehend others' emotions and intentions. Nonetheless, very few studies focused on the pattern of eye movements implicated in the recognition of emotional body language (EBL), demonstrating significant differences in relation to different emotions. A yet unanswered question regards the presence of the "left-gaze bias" (i.e. the tendency to look first, to make more fixations and to spend more looking time on the left side of centrally presented stimuli) while scanning bodies. Hence, the present study aims at exploring both the presence of a left-gaze bias and the modulation of EBL visual exploration mechanisms, by investigating the fixation patterns (number of fixations and latency of the first fixation) of participants while judging the emotional intensity of static bodily postures (Angry, Happy and Neutral, without head). While results on the latency of first fixations demonstrate for the first time the presence of the left-gaze bias while scanning bodies, suggesting that it could be related to the stronger expressiveness of the left hand (from the observer's point of view), results on fixations' number only partially fulfil our hypothesis. Moreover, an opposite viewing pattern between Angry and Happy bodily postures is showed. In sum, the present results, by integrating the spatial and temporal dimension of gaze exploration patterns, shed new light on EBL visual exploration mechanisms.
Assuntos
Emoções , Tecnologia de Rastreamento Ocular , Ira , Movimentos Oculares , Expressão Facial , Fixação Ocular , Humanos , CinésicaRESUMO
The present study addresses a novel issue by investigating whether beholders' sensorimotor engagement with the emotional content of works of art contributes to the formation of their objective aesthetic judgment of beauty. To this purpose, participants' sensorimotor engagement was modulated by asking them to overtly contract the Corrugator Supercilii facial muscles or to refrain from any voluntary facial movement while judging the aesthetic value of painful and neutral facial expressions in select examples of Renaissance and Baroque paintings. Results demonstrated a specific increase in the aesthetic rating of paintings showing painful facial expressions during the congruent activation of the Corrugator Supercilii muscles. Furthermore, participants' empathetic traits and expertise in art were found to correlate directly with the amplitude of the motor enactment effect on aesthetic judgments. For the first time, we show the role of bottom-up bodily driven sensorimotor processes in the objective aesthetic evaluation of works of art.
Assuntos
Estética , Expressão Facial , Músculos Faciais/fisiologia , Contração Muscular/fisiologia , Dor/psicologia , Adulto , Emoções/fisiologia , Feminino , Humanos , Julgamento/fisiologia , Masculino , Estimulação Luminosa , Adulto JovemRESUMO
This is a comparative study of the adsorption dynamics of increasingly longer polyatomic molecules on a planar surface. We perform kinetic Monte Carlo simulations of the gas uptake to identify the molecular mechanisms and parameters that govern the evolution of the adsorbed film to its final equilibrium state. We also develop an analytical model for the adsorption dynamics of mono-atomic gases that demonstrates a direct correlation between the strength of the gas-gas interaction and the adsorption rate dependence with coverage. When this is added to the effect of the orientational freedom of polyatomic molecules, we are able to explain the change in the adsorption rate dependence observed experimentally for longer molecules.
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This is a report on a study of the adsorption characteristics of ethane on aggregates of unopened dahlia-like carbon nanohorns. This sorbent presents two main groups of adsorption sites: the outside surface of individual nanohorns and deep, interstitial spaces between neighbouring nanohorns towards the interior of the aggregates. We have explored the equilibrium properties of the adsorbed ethane films by determining the adsorption isotherms and isosteric heat of adsorption. Computer simulations performed on different model structures indicate that the majority of ethane adsorption occurs on the outer region of the aggregates, near the ends of the nanohorns. We have also measured the kinetics of adsorption of ethane on this sorbent. The measurements and simulations were conducted along several isotherms spanning the range between 120 K and 220 K.
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We analyze the adsorption kinetics of a gas in contact with the open ends of a narrow longitudinal pore, where gas transport along its interior occurs via single-file diffusion mechanisms. By implementing a Kinetic Monte Carlo simulation of the gas dynamics, we obtain the overall change in gas uptake inside the pore and the concentration profile of the adsorbed phase as the system evolves towards equilibrium. Typically, higher external pressure leads to faster kinetics as it happens for adsorption on open surfaces. However, when the pore is exposed to gas at very high pressures, blockage events near the ends of longer pores can slow down the overall adsorption, with desorption and internal diffusion eventually becoming the rate limiting processes. We determine the dependence of these phenomena on the amount of gas adsorbed, binding energy and length of the pore.
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The adsorption dynamics of diatomic molecules on solid surfaces is examined by using a Kinetic Monte Carlo algorithm. Equilibration times at increasing loadings are obtained, and explained based on the elementary processes that lead to the formation of the adsorbed film. The ability of the molecules to change their orientation accelerates the overall uptake and leads to competitive kinetic behaviour between the different orientations. The dependence of the equilibration time on coverage follows the same decreasing trend obtained experimentally for ethane adsorption on closed-end carbon nanotube bundles. The exploration of molecule-molecule interaction effects on this trend provides relevant insights to understand the kinetic behaviour of other species, from simpler molecules to larger polyatomic molecules, adsorbing on surfaces with different binding strength.
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We present results for the isothermal adsorption kinetics of methane, hydrogen, and tetrafluoromethane on closed-ended single-walled carbon nanotubes. In these experiments, we monitor the pressure decrease as a function of time as equilibrium is approached, after a dose of gas is added to the cell containing the nanotubes. The measurements were performed at different fractional coverages limited to the first layer. The results indicate that, for a given coverage and temperature, the equilibration time is an increasing function of E/(k(B)T), where E is the binding energy of the adsorbate and k(B)T is the thermal energy. These findings are consistent with recent theoretical predictions and computer simulations results that we use to interpret the experimental measurements.
Assuntos
Nanotubos de Carbono/química , Temperatura , Termodinâmica , Adsorção , Sítios de Ligação , Fluorocarbonos/química , Hidrogênio/química , Cinética , Metano/química , Propriedades de Superfície , Fatores de TempoRESUMO
We present the combined results of a computer simulation and adsorption isotherm investigation of CF4 films on purified HiPco nanotubes. The experimental measurements found two substeps in the adsorption data. The specific surface area of the sample and the coverage dependence of the isosteric heat of adsorption of the films were determined from the measurements. The simulations, conducted for homogeneous bundles of close-ended tubes, also found two substeps in the first layer data: one corresponding to adsorption on the grooves and a second one, at higher pressures, corresponding to adsorption on the outside surface of the tubes. Our computer simulations are in very good agreement with the experimental data.
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A lattice-gas model of adsorption inside cylindrical pores is evaluated with Monte Carlo simulations. The model incorporates two kinds of sites: (a line of) "axial" sites and surrounding "cylindrical shell" sites, in the ratio 1:7. The adsorption isotherms are calculated in either the grand canonical or canonical ensembles. At low temperature, there occur quasitransitions that would be genuine thermodynamic transitions in mean-field theory. Comparisons between the Monte Carlo and mean-field theory results for the heat capacity and adsorption isotherms are provided.
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We employ a simple model to describe the phase behavior of 4He and Ar in a hypothetical porous material consisting of a regular array of infinitely long, solid, parallel cylinders. We find that high porosity geometries exhibit two transitions: from vapor to film and from film to capillary condensed liquid. At low porosity, the film is replaced by a "necking" configuration, and for a range of intermediate porosity there are three transitions: from vapor to film, from film to necking and from necking to a capillary condensed phase.
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We explore the thermodynamic behavior of gases adsorbed within a nanopore. The theoretical description employs a simple lattice gas model, with two species of site, expected to describe various regimes of adsorption and condensation behavior. The model includes four hypothetical phases: a cylindrical shell phase (S), in which the sites close to the cylindrical wall are occupied, an axial phase (A), in which sites along the cylinder's axis are occupied, a full phase (F), in which all sites are occupied, and an empty phase (E). We obtain exact results at T=0 for the phase behavior, which is a function of the interactions present in any specific problem. We obtain the corresponding results at finite T from mean field theory. Finally, we examine the model's predicted phase behavior of some real gases adsorbed in nanopores.
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Adsorbed gases within, or outside of, carbon nanotubes may be analyzed with an approximate model of adsorption on lattice sites situated on a cylindrical surface. Using this model, the ground state energies of alternative lattice structures are calculated, assuming Lennard-Jones pair interactions between the particles. The resulting energy and equilibrium structure are nonanalytic functions of radius (R) because of commensuration effects associated with the cylindrical geometry. Specifically, as R varies, structural transitions occur between configurations differing in the "ring number," defined as the number of atoms located at a common value of the longitudinal coordinate (z). The thermodynamic behavior of this system is evaluated at finite temperatures, using a Hamiltonian with nearest-neighbor interactions. The resulting specific heat bears a qualitative resemblance to that of the one-dimensional Ising model.
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A study is presented of the effects of gas (especially H2) absorption within the interstitial channels of a bundle of carbon nanotubes. The ground state of the system is determined by minimizing the total energy, which includes the molecules' interaction with the tubes, the intertube interaction, and the molecules' mutual interaction (which is screened by the tubes). The consequences of swelling include a reduced threshold pressure for gas uptake and a 2.7% increase in the tubes' breathing mode frequency.
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Eosinophil count and IgA breast milk were evaluated at birth in 120 mother-newborn pairs with an 18-month prospective follow-up study. Our study showed a higher risk of developing atopic eczema in newborns with eosinophil count higher than 500 cell/mm3 and with IgA breast milk less than 220 mg/dl (odds ratio 17.6 CI 5.4 to 57.2 p < 0.000086). IgA breast milk is significantly less and eosinophil count is significantly higher at birth in children who develop atopic eczema. This study demonstrates the usefulness of newborn eosinophil count and mother total IgA breast milk level as combined risk factors in the development of atopic eczema in breast-fed babies.
Assuntos
Dermatite Atópica/imunologia , Eosinófilos/imunologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina A/imunologia , Proteínas do Leite/imunologia , Leite Humano/imunologia , Adulto , Aleitamento Materno , Distribuição de Qui-Quadrado , Dermatite Atópica/sangue , Feminino , Seguimentos , Humanos , Recém-Nascido , Contagem de Leucócitos , Modelos Lineares , Fatores de RiscoRESUMO
Basophil granulocytes and their mediators are involved in the pathogenesis of allergic inflammation. We evaluated basophil count, blood histamine content, eosinophil count and serum total IgE levels in one hundred-thirteen healthy newborns at birth. 102 children were prospectively studied with a follow up to 18 months of age for development of atopic disorders. No difference was found in newborns with biparental family history of atopy (FHA) in comparison with newborns with monoparental FHA and with newborns without FHA. Children who developed atopic disorders had neonatal basophil counts higher than those who did not develop atopic symptoms (p = 0.03). No significant correlation was found between basophil and eosinophil counts (rs = 0.013), between basophil count and serum total IgE levels (rs = 0.012) and between basophil count and blood histamine content. Positive predictive value and sensitivity of basophil count for allergy up to 18 months of age was only 33% and 27%, respectively. Our data indicate that an increased basophil count at birth is not associated with FHA and is not a good predictive marker of atopy.
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Basófilos , Hipersensibilidade Imediata/sangue , Hipersensibilidade Imediata/diagnóstico , Humanos , Recém-Nascido , Contagem de Leucócitos , Valor Preditivo dos TestesRESUMO
We evaluated respiratory mechanics in healthy or with respiratory diseases newborns and infants. We used a facial mask collected with a pneumotachograph and a software. We obtained flow-volume and flow-time loops which are useful for evaluating lung function in non collaborating infants. We studied babies with pulmonary broncho-dysplasia, vascular ring, bronchial asthma and others neonatal respiratory problems. Tptef/Texp evaluated in healthy newborns during flow-time seems to be predictive for respiratory problems.
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Mecânica Respiratória/fisiologia , Humanos , Lactente , Recém-NascidoRESUMO
Basophil granulocytes and their mediators are involved in the pathogenesis of allergic inflammation. We evaluated basophil count, blood histamine content, eosinophil count and serum total IgE levels in one hundred-thirteen healthy newborns at birth. 108 children were prospectively studied with a follow-up to 18 months of age for development of topic disorders. No difference was found in newborns with biparental family history of atopy (FHA) in comparison with newborns with monoparental FHA and with newborns without FHA. Children who developed atopic disorders had neonatal basophil count higher than those who did not develop atopic symptoms (p = 0.03). No significant correlation was found between basophil and eosinophil counts (r = 0.013), between basophil count and serum total IgE levels (r = 0.012) and between basophil count and blood histamine content. Positive predictive value and sensitivity of basophil count for allergy up to 18 months of age was respectively only 33% and 27%. Our data indicate that an increased basophil count at birth is not associated with FHA and is not a good predictive marker of atopy.
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Basófilos , Hipersensibilidade/diagnóstico , Contagem de Leucócitos , Fatores Etários , Eosinófilos , Seguimentos , Histamina/sangue , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/imunologia , Imunoglobulina E/análise , Lactente , Recém-Nascido , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade , Fatores de TempoRESUMO
We describe the eosinophil granulocyte's immunobiology and pediatric management implications. Moreover, we review our results about eosinophil count in newborn as a predictive marker of atopy.
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Eosinófilos , Adolescente , Fatores Etários , Asma/imunologia , Criança , Pré-Escolar , Dermatite Atópica/imunologia , Eosinófilos/imunologia , Eosinófilos/fisiologia , Feminino , Hipersensibilidade Alimentar/imunologia , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Gravidez , PrognósticoRESUMO
Eosinophil count (EC) were obtained from 312 newborns with and 172 without family history of atopy (FHA). The EC were higher in infants with than without FHA. Elevated EC were recorded in babies of parietaria sensitive mothers born in the spring, as compared to other seasons. The predictive value of EC with regard to development of atopic diseases up to 18 months of age was prospectively studied in 103 newborns with FHA. Using 5 x 10(8) cells/l as cut-off level the predictive allergy value was 41%. Elevated EC appears to be a marker of atopy in newborns.