Around 1508, Leonardo DaVinci observed a curious image of the sun formed by a floating bubble. Now, some 500 years later, we give a full picture of the surprisingly rich phenomenology of the light pattern formed below surface bubbles. Under shallow illumination, and for shallow depths of water, the caustic deviates from the symmetrical astroid shape obtained for larger depths and/or near-vertical illumination. Whereas the astroid caustic involves refraction through the outer meniscus only, more complex ray paths explain the asymmetric, multicomponent (composite) light pattern.
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http://dx.doi.org/10.1364/AO.426424 | DOI Listing |
BMC Public Health
January 2025
Early Start, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, NSW, 2522, Australia.
Introduction: The relationship between 24-h movement behaviours (i.e. sleep, sedentary behaviour and physical activity) and adiposity in preschoolers remains unclear.
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January 2025
School of Nursing and Rehabilitation, Cheeloo College of Medicine, Shandong University, 44 Wenhua Xi Road, Lixia District, Jinan, Shandong Province, China.
Background: Patients with chronic obstructive pulmonary disease (COPD) and sarcopenia experience poorer clinical prognosis. Although sedentary behaviour (SB) is common risk factor for COPD, its relationship with sarcopenia in this specific population remains unclear.
Methods: This is a cross-sectional survey of participants aged 40 and above with COPD, involving 27 communities and 2 hospitals' outpatient departments.
BMC Plant Biol
January 2025
Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh, 11451, Saudi Arabia.
Background: The present research work was done to evaluate the anatomical differences among selected species of the family Bignoniaceae, as limited anatomical data is available for this family in Pakistan. Bignoniaceae is a remarkable family for its various medicinal properties and anatomical characterization is an important feature for the identification and classification of plants.
Methodology: In this study, several anatomical structures were examined, including stomata type and shape, leaf epidermis shape, epidermal cell size, and the presence or absence of trichomes and crystals (e.
Sci Rep
January 2025
Sir Jules Thorn Sleep and Circadian Neuroscience Institute, Kavli Institute for Nanoscience Discovery, Nuffield Department of Clinical Neurosciences, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford, OX1 3QU, UK.
The study of circadian rhythms has been critically dependent upon analysing mouse home cage activity, typically employing wheel running activity under different lighting conditions. Here we assess a novel method, the Digital Ventilated Cage (DVC, Tecniplast SpA, Italy), for circadian phenotyping. Based upon capacitive sensors mounted under black individually ventilated cages with inbuilt LED lighting, each cage becomes an independent light-controlled chamber.
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January 2025
Aquatic Ecology, Department of Biology, Lund University, Lund, Sweden.
Environmental variation has long been considered a key driver of evolutionary change, predicted to shape different strategies, such as genetic specialization, plasticity, or bet-hedging to maintain fitness. However, little evidence is available with regards to how the periodicity of stressors may impact fitness across generations. To address this gap, I conducted a reciprocal split-brood experiment using the freshwater crustacean, Daphnia magna, and an ecologically relevant environmental stressor, ultraviolet radiation (UVR).
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