2,472 research outputs found
Cloud Chamber: A Performance with Real Time Two-Way Interaction between Subatomic Particles and Violinist
‘Cloud Chamber’ - a composition by Alexis Kirke, Antonino Chiaramonte, and Anna Troisi - is a live performance in which the invisible quantum world becomes visible as a violinist and subatomic particle tracks interact together. An electronic instrument was developed which can be “played” live by radioactive atomic particles. Electronic circuitry was developed enabling a violin to create a physical force field that directly affects the ions generated by cosmic radiation particles. This enabled the violinist and the ions to influence each other musically in real time. A glass cloud chamber was used onstage to make radioactivity visible in bright white tracks moving within, with the tracks projected onto a large screen
Clinical exercise testing in children and adolescents with cystic fibrosis.
ArticleThis is the author version of an article published in Pediatric Physical Therapy, 2009, Vol. 21, Iss. 3, pp. 275-281. The final published version is available via: http://dx.doi.org/10.1097/PEP.0b013e3181b15445PURPOSE:
To review the most common field and laboratory exercise tests available for children and adolescents with cystic fibrosis (CF).
METHODS:
Relevant studies for this review were identified by electronic search of Medline and PubMed databases between the years 1958 and 2008. The bibliographies of all accessed publications were also searched. Key descriptors were cystic fibrosis, exercise testing, aerobic fitness, children, and adolescents.
RESULTS:
Five field tests were selected for presentation, including discussion of their strengths and weaknesses. Laboratory tests measuring aerobic and anaerobic responses to exercise in children with CF were also selected for presentation and discussed along with a summary of safety considerations for exercise testing of children with CF.
CONCLUSION:
Exercise testing is regarded an important prognostic tool in CF care. However, despite its beneficial effects, clinical exercise testing seems underused. Clinicians and their staff should encourage patients with CF to be physically active and recommend exercise testing annually
Geometric picture of quantum discord for two-qubit quantum states
Among various definitions of quantum correlations, quantum discord has
attracted considerable attention. To find analytical expression of quantum
discord is an intractable task. Exact results are known only for very special
states, namely, two-qubit X-shaped states. We present in this paper a geometric
viewpoint, from which two-qubit quantum discord can be described clearly. The
known results about X state discord are restated in the directly perceivable
geometric language. As a consequence, the dynamics of classical correlations
and quantum discord for an X state in the presence of decoherence is endowed
with geometric interpretation. More importantly, we extend the geometric method
to the case of more general states, for which numerical as well as analytica
results about quantum discord have not been found yet. Based on the support of
numerical computations, some conjectures are proposed to help us establish
geometric picture. We find that the geometric picture for these states has
intimate relationship with that for X states. Thereby in some cases analytical
expressions of classical correlations and quantum discord can be obtained.Comment: 9 figure
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