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Defect patterns on the curved surface of fish retinae suggest a mechanism of cone mosaic formation
User Collection- Creator:
- Nunley, Hayden, Nagashima, Mikiko, Martin, Kamirah, Lorenzo Gonzalez, Alcides, Suzuki, Sachihiro C., Norton, Declan A., Wong, Rachel O. L., Raymond, Pamela A., and Lubensky, David K.
- Description:
- The outer epithelial layer of zebrafish retinae contains a crystalline array of cone photoreceptors, called the cone mosaic. As this mosaic grows by mitotic addition of new photoreceptors at the rim of the hemispheric retina, topological defects, called “Y-Junctions”, form to maintain approximately constant cell spacing. The generation of topological defects due to growth on a curved surface is a distinct feature of the cone mosaic not seen in other well-studied biological patterns like the R8 photoreceptor array in the _ Drosophila compound eye. Since defects can provide insight into cell-cell interactions responsible for pattern formation, here we characterize the arrangement of cones in individual Y-Junction cores (see Set of images for Figures 1 and 2 and 6 and Supplementary Figure 7) as well as the spatial distribution of Y-junctions across entire retinae (see Dataset for analyzing spatial distribution of Y-junctions in flat-mounted retinae). We find that for individual Y-junctions, the distribution of cones near the core corresponds closely to structures observed in physical crystals (see Set of images for Figures 1 and 2 and 6 and Supplementary Figure 7). In addition, Y-Junctions are organized into lines, called grain boundaries, from the retinal center to the periphery (see Dataset for analyzing spatial distribution of Y-junctions in flat-mounted retinae and Dataset for measuring tendency of Y-junctions to line up into grain boundaries during incorporation into retinae). In physical crystals, regardless of the initial distribution of defects, defects can coalesce into grain boundaries via the mobility of individual particles. By imaging in live fish, we demonstrate that grain boundaries in the cone mosaic instead appear during initial mosaic formation, without requiring defect motion (see Dataset for measuring tendency of Y-junctions to line up into grain boundaries during incorporation into retinae and Dataset for analyzing Y-junction motion in live fish retinae). Motivated by this observation, we show that a computational model of repulsive cell-cell interactions generates a mosaic with grain boundaries (see Code and example simulations of phase-field crystal model (for cone mosaic formation)). In contrast to paradigmatic models of fate specification in mostly motionless cell packings (see Code and accompanying input data for simulating lateral inhibition on motionless cell packing), this finding emphasizes the role of cell motion, guided by cell-cell interactions during differentiation, in forming biological crystals. Such a route to the formation of regular patterns may be especially valuable in situations, like growth on a curved surface, where the resulting long-ranged, elastic, effective interactions between defects can help to group them into grain boundaries.
- Keyword:
- zebrafish cone mosaic, lattice vectors, topological defects, tissue patterning, grain boundaries, lateral inhibition, photoconversion, phase-field crystal model, and defect motion
- Discipline:
- Science
7Works -
- Creator:
- Bougher, S. W. (University of Michigan) and Brecht, A. S. (NASA Ames Research Center)
- Description:
- This work examines the planetary wave-induced variability within the upper mesosphere/lower thermosphere of Venus by utilizing the Venus Thermospheric General Circulation Model (VTGCM). Rossby and Kelvin wave perturbations are driven by variations in the geopotential height of the VTGCM lower boundary (~70 km). A suite of simulations was conducted to examine the impact of the individual and combined waves propagating from two different lower boundary conditions (uniform and varying). The Kelvin wave is the more dominant wave which produces the most variability, as was shown in Hoshino et al., 2012. The combination of the Kelvin and Rossby waves provides a maximum temperature amplitude of 13 K at 92 km and maximum zonal wind amplitude of 23 m/s at 102 km. The combined waves overall are able to propagate up to 125 km. Most of the variation within the temperature, winds, and composition occurs between 70 km and 110 km. The varying lower boundary increases the magnitude of the wave deposition but weakly changes the propagation altitude. The thermal variation due to the planetary waves does not reproduce most observed variations. The simulated O2 IR nightglow emission is sensitive to the waves with respect to intensity and local time, but lacks latitudinal variation. The integrated intensity ranges from 1.2 MR to 1.65 MR and the local time ranges from 0.33 local time to 23.6 local time. Overall, planetary waves do affect the atmospheric structure, but there are still observed large variations that planetary waves alone cannot explain (i.e. thermal structure).
- Keyword:
- Venus, planetary waves, upper mesophere, lower thermosphere, and O2 nightglow
- Citation to related publication:
- Brecht, A. S., Bougher, S. W., Shields, D., & Liu, H.-L. (2021). Planetary-scale wave impacts on the Venusian upper mesosphere and lower thermosphere. Journal of Geophysical Research: Planets, 126, e2020JE006587. https://doi.org/10.1029/2020JE006587
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right distal tibia of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81821), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- Zhang, Yizhen
- Description:
- We collected hours of functional magnetic resonance imaging data from human subjects listening to natural stories. We developed a predictive model of the voxel-wise response and further applied it to thousands of new words to understand how the brain stores and connects different concepts. and This is a dataset for the paper: Zhang, Y., Han, K., Worth, R., & Liu, Z. (2020). Connecting concepts in the brain by mapping cortical representations of semantic relations. Nature communications, 11(1), 1-13. https://doi.org/10.1038/s41467-020-15804-w. This project is also documented at https://osf.io/eq2ba/.
- Keyword:
- fMRI, natural story comprehension, neural encoding, semantic processing, word relations, and naturalistic stimuli
- Citation to related publication:
- Zhang, Y., Han, K., Worth, R., & Liu, Z. (2020). Connecting concepts in the brain by mapping cortical representations of semantic relations. Nature communications, 11(1), 1-13. https://doi.org/10.1038/s41467-020-15804-w
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right proximal metatarsal 1 of the Cantius trigonodus (University of Michigan Museum of Paleontology catalog number UMMP VP 81822), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right cuboid of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81823), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right calcaneum of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81821), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right astragalar [astragalus] body of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81827), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right navicular of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81831), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for a right medial cuneiform (entocuneiform) of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81820), as a series of TIFF images. Raw projections are not included in this dataset.
- Keyword:
- Paleontology, Fossil, CT, Primates, Notharctidae, UMMP, University of Michigan Museum of Paleontology, Eocene, and CTEES
- Discipline:
- Science