20 research outputs found
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Dyspnea-related cues engage the prefrontal cortex - evidence from functional brain imaging in COPD
Dyspnea is the major source of disability in chronic obstructive pulmonary disease (COPD). In COPD, environmental cues (e.g. the prospect of having to climb stairs) become associated with dyspnea, and may trigger dyspnea even before physical activity commences. We hypothesised that brain activation relating to such cues would be different between COPD patients and healthy controls, reflecting greater engagement of emotional mechanisms in patients.
Methods: Using FMRI, we investigated brain responses to dyspnea-related word cues in 41 COPD patients and 40 healthy age-matched controls. We combined these findings with scores of self-report questionnaires thus linking the FMRI task with clinically relevant measures. This approach was adapted from studies in pain that enables identification of brain networks responsible for pain processing despite absence of a physical challenge. Results: COPD patients demonstrate activation in the medial prefrontal cortex (mPFC), and anterior cingulate cortex (ACC) which correlated with the visual analogue scale (VAS) response to word cues. This activity independently correlated with patient-reported questionnaires of depression, fatigue and dyspnea vigilance. Activation in the anterior insula, lateral prefrontal cortex (lPFC) and precuneus correlated with the VAS dyspnea scale but not the questionnaires.
Conclusions: Our findings suggest that engagement of the brain's emotional circuitry is important for interpretation of dyspnea-related cues in COPD, and is influenced by depression, fatigue, and vigilance. A heightened response to salient cues is associated with increased symptom perception in chronic pain and asthma, and our findings suggest such mechanisms may be relevant in COPD
Stimulated creation of quanta during inflation and the observable universe
Inflation provides a natural mechanism to account for the origin of cosmic
structures. The generation of primordial inhomogeneities during inflation can
be understood via the spontaneous creation of quanta from the vacuum. We show
that when the corresponding {\it stimulated} creation of quanta is considered,
the characteristics of the state of the universe at the onset of inflation are
not diluted by the inflationary expansion and can be imprinted in the spectrum
of primordial inhomogeneities. The non-gaussianities (particularly in the
so-called squeezed configuration) in the cosmic microwave background and galaxy
distribution can then tell us about the state of the universe that existed at
the time when quantum field theory in curved spacetime first emerged as a
plausible effective theory.Comment: Awarded with the First Prize in the Gravity Research Foundation Essay
Competition 201
A Semi-Analytical Solution for Large-Scale Injection-Induced Pressure Perturbation and Leakage in a Laterally Bounded Aquifer–Aquitard System
Effect of Low Intensity Helium-Neon (He-Ne) Laser Irradiation on Diabetic Wound Healing Dynamics
Reflexity in teams: A measure and correlates.
Reflexivity - the extent to which teams reflect upon and modify their functioning - has been identified as a possible key factor in the effectiveness of work teams. The aim of the present study was to develop a questionnaire to measure (aspects of) reflexivity, with a focus on team reflection. The questionnaire was tested in two different samples, namely a first sample of 59 teams from 14 different organisations (Study 1) and a confirmation sample of 59 school management teams (Study 2). In both samples, two factors of reflection were identified. These were labeled evaluation/learning and discussing processes. Scale statistics showed good psychometric properties for the scales in both studies. We conclude that the scales form a parsimonious and valid instrument to assess reflexivity in teams. © 2007 International Association of Applied Psychology