We derive an uncertainty relation for two unitary operators which obey a commutation relation of the form UV=e(i phi) VU. Its most important application is to constrain how much a quantum state can be localized simultaneously in two mutually unbiased bases related by a discrete fourier transform. It provides an uncertainty relation which smoothly interpolates between the well-known cases of the Pauli operators in two dimensions and the continuous variables position and momentum. This work also provides an uncertainty relation for modular variables, and could find applications in signal processing. In the finite dimensional case the minimum uncertainty states, discrete analogues of coherent and squeezed states, are minimum energy solutions of Harper's equation, a discrete version of the harmonic oscillator equation.
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http://dx.doi.org/10.1103/PhysRevLett.100.190401 | DOI Listing |
Occup Med (Lond)
January 2025
Project Management, UKM Pakarunding, Level 3, Bangunan Wawasan, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
Background: The symptoms of Long coronavirus disease 2019 (Covid-19) are heterogeneous, creating uncertainty for employers regarding the diagnosis. The prevalence of Long Covid-19 in the workforce is also unknown. Furthermore, workers affected by Long Covid-19 encounter considerable difficulties in ensuring work safety and returning to their jobs due to this condition.
View Article and Find Full Text PDFBMJ Open
January 2025
Nursing, Brock University, St. Catharines, Ontario, Canada.
Objectives: This study aimed to explore the perceptions of donation coordinators in Canada and understand how the COVID-19 pandemic impacted their work activities.
Design: A sequential mixed-method design incorporating a cross-sectional survey investigating demographic data, substance use and abuse and perceived stress related to the pandemic and semistructured qualitative interviews to further investigate those.
Setting: Organ donation organisations across Canada.
Environ Int
January 2025
Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Joint International Research Laboratory of Climate and Environment Change, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Estimating PM exposure and its health impacts in cities involves large uncertainty due to the limitations of model resolutions. Consequently, attributing the sources of PM-related health impacts at the city level remains challenging. We characterize the health impacts associated with chronic PM exposure and anthropogenic emissions in Shanghai using a chemical transport model (GEOS-Chem) and its adjoint.
View Article and Find Full Text PDFAnn N Y Acad Sci
January 2025
NewClimate Institute, Cologne, Germany.
Globally, more than 100 countries have adopted net-zero targets. Most studies agree on how this increases the chance of keeping end-of-century global warming below 2°C. However, they typically make assumptions about net-zero targets that do not capture uncertainties related to gas coverage, sector coverage, sinks, and removals.
View Article and Find Full Text PDFMalar J
January 2025
Family and Community Health, Fred N. Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana.
Background: Malaria is a disease deeply rooted in poverty. Malaria in pregnant women leads to severe complications, including low birth weight and neonatal mortality, which can adversely affect both mother and child. This study aimed to identify the factors associated with malaria in pregnancy among women attending antenatal care (ANC) clinics in three districts of the Ashanti Region, Ghana.
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