304 research outputs found
Spatiotemporal dynamics of quantum jumps with Rydberg atoms
We study the nonequilibrium dynamics of quantum jumps in a one-dimensional
chain of atoms. Each atom is driven on a strong transition to a short-lived
state and on a weak transition to a metastable state. We choose the metastable
state to be a Rydberg state so that when an atom jumps to the Rydberg state, it
inhibits or enhances jumps in the neighboring atoms. This leads to rich
spatiotemporal dynamics that are visible in the fluorescence of the strong
transition.Comment: 10 page
Collective quantum jumps of Rydberg atoms
We study an open quantum system of atoms with long-range Rydberg interaction,
laser driving, and spontaneous emission. Over time, the system occasionally
jumps between a state of low Rydberg population and a state of high Rydberg
population. The jumps are inherently collective and in fact exist only for a
large number of atoms. We explain how entanglement and quantum measurement
enable the jumps, which are otherwise classically forbidden.Comment: 4 page
The feasibility of a Comprehensive Resilience-building psychosocial Intervention (CREST) for people with dementia in the community: protocol for a non-randomised feasibility study
Background: A dementia diagnosis can prevent people from participating in society, leading to a further decline in cognitive, social and physical health. However, it may be possible for people with dementia to continue to live meaningful lives and continue to participate actively in society if a supportive psychosocial environment exists. Resilience theory, which focuses on strengthening personal attributes and external assets in the face of serious challenges, may provide a scaffold on which an inclusive multifaceted psychosocial supportive environment can be built. This protocol paper describes a study to determine the feasibility of conducting a multifaceted complex resilience building psychosocial intervention for people with dementia and their caregivers living in the community. Methods: This is a non-randomised feasibility study. Ten participants with dementia and their primary caregivers living in the community will be recruited and receive the CREST intervention. The intervention provides (a) a 7-week cognitive stimulation programme followed by an 8-week physical exercise programme for people with dementia and (b) a 6-week educational programme for caregivers. Members of the wider community will be invited to a dementia awareness programme and GP practices to a dementia training workshop. Trained professionals will deliver all intervention components. Outcomes will assess the feasibility and acceptability of all study processes. The feasibility and acceptability of a range of outcomes to be collected in a future definitive trial, including economic measurements, will also be explored. Finally, social marketing will be used to map a route toward stigma change in dementia for use in a subsequent trial. Quantitative feasibility outcome assessments will be completed at baseline and after completion of the 15-week intervention while qualitative data will be collected at recruitment, baseline, during and post-intervention delivery. Conclusion: This feasibility study will provide evidence regarding the feasibility and acceptability of a comprehensive multifaceted psychosocial intervention programme for people with dementia and their caregivers (CREST). The results will be used to inform the development and implementation of a subsequent RCT, should the findings support feasibility
Implications of Action-Oriented Paradigm Shifts in Cognitive Science
An action-oriented perspective changes the role of an individual from a passive observer to an actively engaged agent interacting in a closed loop with the world as well as with others. Cognition exists to serve action within a landscape that contains both. This chapter surveys this landscape and addresses the status of the pragmatic turn. Its potential influence on science and the study of cognition are considered (including perception,
social cognition, social interaction, sensorimotor entrainment, and language acquisition) and its impact on how neuroscience is studied is also investigated (with the notion that brains do not passively build models, but instead support the guidance of action).
A review of its implications in robotics and engineering includes a discussion of the application of enactive control principles to couple action and perception in robotics as well as the conceptualization of system design in a more holistic, less modular manner. Practical applications that can impact the human condition are reviewed (e.g., educational applications, treatment possibilities for developmental and psychopathological disorders, the development of neural prostheses). All of this foreshadows the potential societal implications of the pragmatic turn. The chapter concludes that an action-oriented approach emphasizes a continuum of interaction between technical aspects of cognitive systems and robotics, biology, psychology, the social sciences, and the humanities,
where the individual is part of a grounded cultural system
Skeletal muscle NOX4 is required for adaptive responses that prevent insulin resistance
Reactive oxygen species (ROS) generated during exercise are considered integral for the health-promoting effects of exercise. However, the precise mechanisms by which exercise and ROS promote metabolic health remain unclear. Here, we demonstrate that skeletal muscle NADPH oxidase 4 (NOX4), which is induced after exercise, facilitates ROS-mediated adaptive responses that promote muscle function, maintain redox balance, and prevent the development of insulin resistance. Conversely, reductions in skeletal muscle NOX4 in aging and obesity contribute to the development of insulin resistance. NOX4 deletion in skeletal muscle compromised exercise capacity and antioxidant defense and promoted oxidative stress and insulin resistance in aging and obesity. The abrogated adaptive mechanisms, oxidative stress, and insulin resistance could be corrected by deleting the H2O2-detoxifying enzyme GPX-1 or by treating mice with an agonist of NFE2L2, the master regulator of antioxidant defense. These findings causally link NOX4-derived ROS in skeletal muscle with adaptive responses that promote muscle function and insulin sensitivity
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