Alfvén waves have been invoked as a possible mechanism for the heating of the Sun's outer atmosphere, or corona, to millions of degrees and for the acceleration of the solar wind to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the solar atmosphere. We used images of high temporal and spatial resolution obtained with the Solar Optical Telescope onboard the Japanese Hinode satellite to reveal that the chromosphere, the region sandwiched between the solar surface and the corona, is permeated by Alfvén waves with strong amplitudes on the order of 10 to 25 kilometers per second and periods of 100 to 500 seconds. Estimates of the energy flux carried by these waves and comparisons with advanced radiative magnetohydrodynamic simulations indicate that such Alfvén waves are energetic enough to accelerate the solar wind and possibly to heat the quiet corona.
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http://dx.doi.org/10.1126/science.1151747 | DOI Listing |
Nutr Res
January 2025
Department of Molecular Medicine, University of Padova, Padova, Italy; IMDEA-Food, Madrid, Spain. Electronic address:
l-Theanine is a unique non-protein amino acid found abundantly in tea leaves. Interest in its potential use as a dietary supplement has surged recently, especially claims related to promoting relaxation and cognitive enhancement. This review surveys the chemistry, metabolism, and purported biological activities of l-theanine.
View Article and Find Full Text PDFPLoS One
January 2025
Institute of Management, Accounting and Finance, Leuphana University Lüneburg, Lüneburg, Lower Saxony, Germany.
Climate change has heightened the need to understand physical climate risks, such as the increasing frequency and severity of heat waves, for informed financial decision-making. This study investigates the financial implications of extreme heat waves on stock returns in Europe and the United States. Accordingly, the study combines meteorological and stock market data by integrating methodologies from both climate science and finance.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
College of Optometry, University of Houston, Houston, TX, USA.
Purpose: To characterize frequency-dependent wave speed dispersion in the human cornea using microliter air-pulse optical coherence elastography (OCE), and to evaluate the applicability of Lamb wave theory for determining corneal elastic modulus using high-frequency symmetric (S0) and anti-symmetric (A0) guided waves in cornea.
Methods: Wave speed dispersion analysis for transient (0.5 ms) microliter air-pulse stimulation was performed in four rabbit eyes ex vivo and compared to air-coupled ultrasound excitation.
J Res Adolesc
March 2025
Department of Psychology, University of Notre Dame, Notre Dame, Indiana, USA.
Families manage daily conflict through communication and healthy family communication is critical to promoting better family relationships and youth adjustment. Community families without high-risk factors, such as domestic dispute or clinical problems, are no less affected by the ramifications of poor communication and conflict management. However, there is limited translational research on community families analyzing the changes in parent-adolescent communication quality.
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