155 research outputs found
Multifunctional sandwich structure for electromagnetic absorption and mechanical performances
A sandwich panel based on a multiscale architectured material is developed for structural and EM absorption performances. At the nanoscale level, carbon nanotubes are dispersed in a polymer to obtain a conductive material. This composite is then foamed into a micro porous solid to improve EM absorption and to decrease the density. The foam is inserted in a millimeter scale hexagonal metallic honeycomb lattice. The combination of the metallic honeycomb and the polymeric foam provides high bending, impact and crushing performances and a moderate thermal conductivity. This hybrid is used as core for sandwich panels, produced by the addition of two EM transparent face-sheets made of glass fiber reinforced polymers. EM absorption around 90% is achieved in the 10-40 GHz frequency band with a 8.8 mm thick sandwich panel
Understanding Attentional Biases in Severe Alcohol Use Disorder: A Combined Behavioral and Eye-Tracking Perspective.
RATIONALE: Severe alcohol use disorder (SAUD) is a psychiatric condition linked to cerebral and cognitive consequences. SAUD is notably characterized by an overactivation of the reflexive/reward system when confronted with alcohol-related cues. Such overreactivity generates a preferential allocation of attentional resources toward these cues, labeled as attentional biases (AB). Theoretical assumptions have been made regarding the characteristics of AB and their underlying processes. While often considered as granted, these assumptions remain to be experimentally validated. AIMS: We first identify the theoretical assumptions made by previous studies exploring the nature and role of AB. We then discuss the current evidence available to establish their validity. We finally propose research avenues to experimentally test them. METHODS: Capitalizing on a narrative review of studies exploring AB in SAUD, the current limits of the behavioral measures used for their evaluation are highlighted as well as the benefits derived from the use of eye-tracking measures to obtain a deeper understanding of their underlying processes. We describe the issues related to the theoretical proposals on AB and propose research avenues to test them. Four experimental axes are proposed, respectively, related to the determination of (a) the genuine nature of the mechanisms underlying AB; (b) their stability over the disease course; (c) their specificity to alcohol-related stimuli and (d) their reflexive or controlled nature. CONCLUSIONS: This in-depth exploration of the available knowledge related to AB in SAUD, and of its key limitations, highlights the theoretical and clinical interest of our innovative experimental perspectives capitalizing on eye-tracking measures
Reevaluating the modernization hypothesis
We revisit and critically reevaluate the widely accepted modernization hypothesis which claims that per capita income causes the creation and the consolidation of democracy. Existing studies find support for this hypothesis because they fail to control for the presence of omitted variables. Controlling for these factors either by including country fixed effects in a linear model or by including parameterized random effects in a nonlinear double hazard model removes the correlation between income and the likelihood of transitions to and from democratic regimes. In addition, the estimated fixed effects from the linear model are related to historical factors that affect both the level of income per capita and the likelihood of democracy in a country. This evidence is consistent with the idea that events during critical historical junctures can lead to divergent political–economic development paths, some leading to prosperity and democracy, others to relative poverty and non-democracy
Adult Male Mice Emit Context-Specific Ultrasonic Vocalizations That Are Modulated by Prior Isolation or Group Rearing Environment
Social interactions in mice are frequently analysed in genetically modified strains in order to get insight of disorders affecting social interactions such as autism spectrum disorders. Different types of social interactions have been described, mostly between females and pups, and between adult males and females. However, we recently showed that social interactions between adult males could also encompass cognitive and motivational features. During social interactions, rodents emit ultrasonic vocalizations (USVs), but it remains unknown if call types are differently used depending of the context and if they are correlated with motivational state. Here, we recorded the calls of adult C57BL/6J male mice in various behavioral conditions, such as social interaction, novelty exploration and restraint stress. We introduced a modulator for the motivational state by comparing males maintained in isolation and males maintained in groups before the experiments. Male mice uttered USVs in all social and non-social situations, and even in a stressful restraint context. They nevertheless emitted the most important number of calls with the largest diversity of call types in social interactions, particularly when showing a high motivation for social contact. For mice maintained in social isolation, the number of calls recorded was positively correlated with the duration of social contacts, and most calls were uttered during contacts between the two mice. This correlation was not observed in mice maintained in groups. These results open the way for a deeper understanding and characterization of acoustic signals associated with social interactions. They can also help evaluating the role of motivational states in the emission of acoustic signals
Psychometric properties of the Posttraumatic Cognition Inventory within a Northern Ireland adolescent sample
Flashbulb memories and the underlying mechanisms of their formation: Toward an emotional-integrative model
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