There is a long-lasting debate about the possible functions of zebra stripes. According to one hypothesis, periodical convective air eddies form over sunlit zebra stripes which cool the body. However, the formation of such eddies has not been experimentally studied. Using schlieren imaging in the laboratory, we found: downwelling air streams do not form above the white stripes of light-heated smooth or hairy striped surfaces. The influence of stripes on the air stream formation (facilitating upwelling streams and hindering horizontal stream drift) is negligible higher than 1-2 cm above the surface. In calm weather, upwelling air streams might form above sunlit zebra stripes, however they are blown off by the weakest wind, or even by the slowest movement of the zebra. These results forcefully contradict the thermoregulation hypothesis involving air eddies.
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http://dx.doi.org/10.1038/s41598-021-95105-4 | DOI Listing |
J Exp Biol
January 2025
Independent researcher, 74 Eccleston Square, London, UK.
The function of zebra stripes has long puzzled biologists: contrasted and conspicuous colours are unusual in mammals. The puzzle appears solved: two lines of evidence indicate that they evolved as a protection against biting flies, the geographical coincidence of stripes and exposure to trypanosomiasis in Africa and field experiments showing flies struggling to navigate near zebras. A logical mechanistic explanation would be that stripes interfere with flies' analysis of the optic flow; however, both spatio-temporal aliasing and the aperture effect seem ruled out following recent experiments showing that randomly checked patterns also interfere with flies' capacity to navigate near zebras.
View Article and Find Full Text PDFPhys Rev E
September 2024
Center for Systems Biology Dresden, Dresden 01307, Germany; Max Planck Institute for the Physics of Complex Systems, Dresden 01187, Germany; and Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.
Many animals have patterned fur, feathers, or scales, such as the stripes of a zebra. Turing models, or reaction-diffusion systems, are a class of mathematical models of interacting species that have been successfully used to generate animal-like patterns for many species. When diffusion of the inhibitor is high enough relative to the activator, a diffusion-driven instability can spontaneously form patterns.
View Article and Find Full Text PDFIEEE Trans Vis Comput Graph
September 2024
Data tables are one of the most common ways in which people encounter data. Although mostly built with text and numbers, data tables have a spatial layout and often exhibit visual elements meant to facilitate their reading. Surprisingly, there is an empirical knowledge gap on how people read tables and how different visual aids affect people's reading of tables.
View Article and Find Full Text PDFChemosphere
September 2024
Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA. Electronic address:
The recent application of non-targeted analysis (NTA) techniques in environmental monitoring has revealed numerous novel fluorinated species in surface water, wildlife, and humans in the Cape Fear River (CFR) region of North Carolina. In this study, we have re-examined archived alligator, striped bass, horse, and dog serum as well as archived seabird tissue data from previously reported exposure studies in order to extend the panel of detected novel PFAS. In this study, the compounds CF-(OCF)-COOH, x = 6, 7, 8 (Abbreviated PFO6TeDA, PFO7HxDA, PFO8OcDA, respectively), and 6H-Perfluoro-3-oxa,4-methylhexanesulfonic acid (Nafion byproduct 6) were detected for the first time in environmental tissues even though these analytes were not previously detected in the CFR.
View Article and Find Full Text PDFACS Nano
July 2024
Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of Chemistry, Beihang University, Beijing 100191, P. R. China.
Smart textiles capable of both energy harvesting and multifunctional sensing are highly desirable for next-generation portable electronics. However, there are still challenges that need to be conquered, such as the innovation of an energy-harvesting model and the optimization of interface bonding between fibers and active materials. Herein, inspired by the spiral structure of natural vines, a highly stretchable triboelectric helical yarn (TEHY) was manufactured by twisting the carbon nanotube/polyurethane nanofiber (CNT/PU NF) Janus membrane.
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