Recognizing spontaneous facial expressions of emotion in a small-scale society of Papua New Guinea

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.We report two studies on how residents of Papua New Guinea interpret facial expressions produced spontaneously by other residents of Papua New Guinea. Members of a small-scale indigenous society, Trobrianders (Milne Bay Province; N = 32, 14 to 17 years) were shown 5 facial expressions spontaneously produced by members of another small-scale indigenous society, Fore (Eastern Highlands Province) that Ekman had photographed, labeled, and published in The Face of Man (1980), each as an expression of a basic emotion: happiness, sadness, anger, surprise, and disgust. Trobrianders were asked to use any word they wanted to describe how each person shown felt and to provide valence and arousal ratings. Other Trobrianders (N = 24, 12 to 14 years) were shown the same photographs but asked to choose their response from a short list. In both studies, agreement with Ekman’s predicted labels was low: 0 to 16% and 13 to 38% of observers, respectively

The fear gasping face as a threat display in a Melanesian society

Theory and research showthat humans attribute both emotions and intentions to others on the basis of facial behavior: A gasping face can be seen as showing “fear” and intent to submit. The assumption that such interpretations are pancultural derives largely from Western societies. Here, we report two studies conducted in an indigenous, small-scale Melanesian society with considerable cultural and visual isolation from the West: the Trobrianders of Papua New Guinea. Our multidisciplinary research team spoke the vernacular and had extensive prior fieldwork experience. In study 1, Trobriand adolescents were asked to attribute emotions, social motives, or both to a set of facial displays. Trobrianders showed a mixed and variable attribution pattern, although with much lower agreement than studies of Western samples. Remarkably, the gasping face (traditionally considered a display of fear and submission in the West) was consistently matched to two unpredicted categories: anger and threat. In study 2, adolescents were asked to select the face that was threatening; Trobrianders chose the “fear” gasping face whereas Spaniards chose an “angry” scowling face. Our findings, consistent with functional approaches to animal communication and observations made on threat displays in small-scale societies, challenge the Western assumption that “fear” gasping faces uniformly express fear or signal submission across cultures

Electric Field Control of Soliton Motion and Stacking in Trilayer Graphene

The crystal structure of a material plays an important role in determining its electronic properties. Changing from one crystal structure to another involves a phase transition which is usually controlled by a state variable such as temperature or pressure. In the case of trilayer graphene, there are two common stacking configurations (Bernal and rhombohedral) which exhibit very different electronic properties. In graphene flakes with both stacking configurations, the region between them consists of a localized strain soliton where the carbon atoms of one graphene layer shift by the carbon-carbon bond distance. Here we show the ability to move this strain soliton with a perpendicular electric field and hence control the stacking configuration of trilayer graphene with only an external voltage. Moreover, we find that the free energy difference between the two stacking configurations scales quadratically with electric field, and thus rhombohedral stacking is favored as the electric field increases. This ability to control the stacking order in graphene opens the way to novel devices which combine structural and electrical properties

Reading emotions from faces in two indigenous societies

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.That all humans recognize certain specific emotions from their facial expression—the Universality Thesis—is a pillar of research, theory, and application in the psychology of emotion. Its most rigorous test occurs in indigenous societies with limited contact with external cultural influences, but such tests are scarce. Here we report two such tests. Study 1 was of children and adolescents (N = 68; aged 6-16 years) of the Trobriand Islands (Papua New Guinea, South Pacific) with a Western control group from Spain (N = 113, of similar ages). Study 2 was of children and adolescents (N = 36; same age range) of Matemo Island (Mozambique, Africa). In both studies, participants were shown an array of prototypical facial expressions and asked to point to the person feeling a specific emotion: happiness, fear, anger, disgust, or sadness. The Spanish control group matched faces to emotions as predicted by the Universality Thesis: matching was seen on 83% to 100% of trials. For the indigenous societies, in both studies, the Universality Thesis was moderately supported for happiness: smiles were matched to happiness on 58% and 56% of trials, respectively. For other emotions, however, results were even more modest: 7% to 46% in the Trobriand Islands and 22% to 53% in Matemo Island. These results were robust across age, gender, static versus dynamic display of the facial expressions, and between- versus within-subjects design

Chromatin remodeling in plant development

Plant development results from specific patterns of gene expression that are tightly regulated in a spatio-temporal manner. Chromatin remodeling plays a central role in establishing these expression patterns and maintaining epigenetic transcriptional states through successive rounds of mitosis that take place within a cell lineage. Plant epigenetic switches occur not only at the embryo stage, but also during postembryonic developmental transitions, suggesting that chromatin remodeling activities in plants can provide a higher degree of regulatory flexibility which probably underlies their developmental plasticity. Here, we highlight recent progress in the understanding of plant chromatin dynamic organization, facilitating the activation or repression of specific sets of genes involved in different developmental programs and integrating them with the response to environmental signals. Chromatin conformation controls gene expression both in actively dividing undifferentiated cells and in those already fate-determined. In this context, we first describe chromatin reorganization activities required to maintain meristem function stable through DNA replication and cell division. Organ initiation at the apex, with emphasis on reproductive development, is next discussed to uncover the chromatin events involved in the establishment and maintenance of expression patterns associated with differentiating cells; this is illustrated with the complex epigenetic regulation of the Arabidopsis floral repressor FLOWERING LOCUS C (FLC). Finally, we discuss the involvement of chromatin remodeling in plant responses to environmental cues and to different types of stress conditions. © 2009 UBC Press

<i>Brassica napus</i> Roots Use Different Strategies to Respond to Warm Temperatures

Elevated growth temperatures are negatively affecting crop productivity by increasing yield losses. The modulation of root traits associated with improved response to rising temperatures is a promising approach to generate new varieties better suited to face the environmental constraints caused by climate change. In this study, we identified several Brassica napus root traits altered in response to warm ambient temperatures. Different combinations of changes in specific root traits result in an extended and deeper root system. This overall root growth expansion facilitates root response by maximizing root–soil surface interaction and increasing roots’ ability to explore extended soil areas. We associated these traits with coordinated cellular events, including changes in cell division and elongation rates that drive root growth increases triggered by warm temperatures. Comparative transcriptomic analysis revealed the main genetic determinants of these root system architecture (RSA) changes and uncovered the necessity of a tight regulation of the heat-shock stress response to adjusting root growth to warm temperatures. Our work provides a phenotypic, cellular, and genetic framework of root response to warming temperatures that will help to harness root response mechanisms for crop yield improvement under the future climatic scenario