4,589 research outputs found

    Lateralised sleep spindles relate to false memory generation

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    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.Sleep is known to enhance false memories: After presenting participants with lists of semantically related words, sleeping before recalling these words results in a greater acceptance of unseen “lure” words related in theme to previously seen words. Furthermore, the right hemisphere (RH) seems to be more prone to false memories than the left hemisphere (LH). In the current study, we investigated the sleep architecture associated with these false memory and lateralisation effects in a nap study. Participants viewed lists of related words, then stayed awake or slept for approximately 90 min, and were then tested for recognition of previously seen-old, unseen-new, or unseen-lure words presented either to the LH or RH. Sleep increased acceptance of unseen-lure words as previously seen compared to the wake group, particularly for RH presentations of word lists. RH lateralised stage 2 sleep spindle density relative to the LH correlated with this increase in false memories, suggesting that RH sleep spindles enhanced false memories in the RH

    The NASA aircraft icing research program

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    The objective of the NASA aircraft icing research program is to develop and make available to industry icing technology to support the needs and requirements for all-weather aircraft designs. Research is being done for both fixed wing and rotary wing applications. The NASA program emphasizes technology development in two areas, advanced ice protection concepts and icing simulation. Reviewed here are the computer code development/validation, icing wind tunnel testing, and icing flight testing efforts

    A New Solution of The Cosmological Constant Problems

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    We extend the usual gravitational action principle by promoting the bare cosmological constant (CC) from a parameter to a field which can take many possible values. Variation leads to a new integral constraint equation which determines the classical value of the effective CC that dominates the wave function of the universe. In a realistic cosmological model, the expected value of the effective CC, is calculated from measurable quantities to be O(t_U), as observed, where t_U is the present age of the universe in Planck units,. Any application of our model produces a falsifiable prediction for Λ\Lambda in terms of other measurable quantities. This leads to a specific falsifiable prediction for the observed spatial curvature parameter of Omega_k0=-0.0055. Our testable proposal requires no fine tunings or extra dark-energy fields but does suggest a new view of time and cosmological evolution.Comment: 5 pages; v3: version accepted by Phys. Rev. Let

    NASA's rotorcraft icing research program

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    The objective of the NASA aircraft icing research program is to develop and make available icing technology to support the needs and requirements of industry for all weather aircraft designs. While a majority of the technology being developed is viewed to be generic (i.e., appropriate to all vehicle classes), vehicle specific emphasis is being placed on the helicopter due to its unique icing problems. In particular, some of the considerations for rotorcraft icing are indicated. The NASA icing research program emphasizes technology development in two key areas: ice protection concepts and icing simulation (analytical and experimental). The NASA research efforts related to rotorcraft icing in these two technology areas will be reviewed

    Hemispheric processing of memory is affected by sleep

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    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.Sleep is known to affect learning and memory, but the extent to which it influences behavioural processing in the left and right hemispheres of the brain is as yet unknown. We tested two hypotheses about lateralised effects of sleep on recognition memory for words: whether sleep reactivated recent experiences of words promoting access to the long-term store in the left hemisphere (LH), and whether sleep enhanced spreading activation differentially in semantic networks in the hemispheres. In Experiment 1, participants viewed lists of semantically related words, then slept or stayed awake for 12 h before being tested on seen, unseen but related, or unrelated words presented to the left or the right hemisphere. Sleep was found to promote word recognition in the LH, and to spread activation equally within semantic networks in both hemispheres. Experiment 2 ensured that the results were not due to time of day effects influencing cognitive performance

    International Year of Planet Earth 5. Applications of Seafloor Mapping on the Canadian Atlantic Continental Shelf

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    Canada’s final mapping frontier is its offshore territory. Compared to Canada’s landmass, only a limited portion of Canada’s seafloor has been mapped using the modern technology of multi-beam sonar. Where this high-resolution mapping technique has been applied on Canada’s Atlantic continental margin, insight has been gained into the studies of seafloor habitat mapping, Quaternary history and sea-level change, sediment bedforms and dynamics, and seafloor conditions for in-stream tidal power. Seafloor habitat mapping in Canada provides the knowledge base to effectively manage offshore fisheries, evaluate marine protected areas, minimize the environmental impact of offshore development, and resolve seafloor-use conflicts. Multibeam sonar mapping has revealed a complex glacial landsystem developed on the Canadian Atlantic continental shelf and supports the concept of the late glacial maximum reaching the shelf edge. The application of multibeam sonar technology offers unprecedented images of bedform geomorphology and this knowledge is crucial to understanding sediment mobility and its effect on seafloor habitat, engineering, and infrastructure. To minimize the risk to engineering infrastructure on the seabed, planning of tidal-energy developments in regions of large tidal range requires detailed information about the water depth, seafloor substrate and sediment mobility, and long-term seabed change garnered using multibeam sonar mapping techniques. SOMMAIRE L’ultime frontière de la cartographie du Canada est son territoire extracôtier. Par rapport à son territoire continental, seule une faible portion du territoire extracôtier canadien a été cartographié par la technique moderne d’imagerie sonar multifaisceaux. Là où cette technique de cartographie de haute résolution a été utilisée sur la marge continentale canadienne atlantique, on a pu faire des progrès dans l’étude de cartographie d’habitat du fond marin, de l’histoire quaternaire des fluctuations du niveau de la mer, de la morphologie des couches et de la dynamique sédimentaires, ainsi que des caractéristiques du fond marin en vue de l’installation de centrales marémotrices. La cartographie d’habitat du fond marin permet de constituer une base de connaissances nécessaires pour gérer efficacement la pêche hauturière, établir la valeur des zones marines protégées, minimiser les incidences environ-nementales des activités de mise en valeur extracôtières, et résoudre les conflits d’utilisation des fonds marins. La cartographie par imagerie sonar multifaisceaux a montré qu’un système complexe de terres émergées s’est développé sur le plateau continental atlantique du Canada et qui correspond au concept d’un maximum glaciaire ayant atteint la limite du plateau continental. L’utilisation de la technologie sonar multifaisceaux permet d’obtenir des images sans précédents de la morphologie des dépôts, et ces connaissances sont cruciales pour comprendre la mobilité des sédiments et les répercussions sur l’habitat du fond marin, les aménagements et les infrastructures. Dans le but de minimiser les risques sur les infrastructures installées sur le fond marin, la planification d’installations marémotrices en zones de marées à grandes variations exige des informations détaillées sur la profondeur d’eau, la nature du fond marin et la mobilité des sédiments, ainsi que sur les changements à longs termes obtenues par l’utilisation de technique de cartographie sonar multifaisceaux
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