The Experts below are selected from a list of 84633 Experts worldwide ranked by ideXlab platform
Marcelo T Nicolela - One of the best experts on this subject based on the ideXlab platform.
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optical coherence tomography optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Ping Wei, Marcelo T NicolelaAbstract:Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to the Bruch membrane opening (BMO) (ASCO/BMO offset) to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design Cross-sectional study. Methods Using optical coherence tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids and size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes 264.3 ± 131.1 μm; healthy control subjects 89.0 ± 55.8 μm, P Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA, and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
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oct optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch s membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Marcelo T Nicolela, Jayme R ViannaAbstract:Abstract Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to Bruch’s membrane opening (BMO) (ASCO/BMO offset) in order to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design: Cross-sectional study. Methods Using Optic Coherence Tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids, size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes, 264.3 ± 131.1 um; healthy controls, 89.0 ± 55.8 um, p Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
Jin Wook Jeoung - One of the best experts on this subject based on the ideXlab platform.
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optical coherence tomography optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Ping Wei, Marcelo T NicolelaAbstract:Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to the Bruch membrane opening (BMO) (ASCO/BMO offset) to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design Cross-sectional study. Methods Using optical coherence tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids and size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes 264.3 ± 131.1 μm; healthy control subjects 89.0 ± 55.8 μm, P Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA, and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
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oct optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch s membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Marcelo T Nicolela, Jayme R ViannaAbstract:Abstract Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to Bruch’s membrane opening (BMO) (ASCO/BMO offset) in order to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design: Cross-sectional study. Methods Using Optic Coherence Tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids, size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes, 264.3 ± 131.1 um; healthy controls, 89.0 ± 55.8 um, p Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
Roberto Scarpa - One of the best experts on this subject based on the ideXlab platform.
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source mechanisms of explosions at stromboli volcano italy determined from moment tensor inversions of very long period data
Journal of Geophysical Research, 2003Co-Authors: Bernard Chouet, Phillip Dawson, Takao Ohminato, M Martini, Gilberto Saccorotti, Flora Giudicepietro, Gaetano De Luca, G Milana, Roberto ScarpaAbstract:[1] Seismic data recorded in the 2–30 s band at Stromboli Volcano, Italy, are analyzed to quantify the source mechanisms of Strombolian explosions during September 1997. To determine the source-Centroid location and source mechanism, we minimize the residual error between data and synthetics calculated by the finite difference method for a point source embedded in a homogeneous elastic medium that takes topography into account. Two source Centroids are identified, each representative of the distinct event types associated with explosive eruptions from two different vents. The observed waveforms are well reproduced by our inversion, and the two source Centroids that best fit the data are offset 220 and 260 m beneath and � 160 m northwest of the active vents. The source mechanisms include both moment-tensor and single-force components. The principal axes of the moment tensor have amplitude ratios 1:1:2, which can be interpreted as representative of a crack, if one assumes the rock matrix at the source to have a Poisson ratio n = 1/3, a value appropriate for hot rock. Both imaged cracks dip � 60� to the northwest and strike northeast–southwest along a direction parallel to the elongation of the volcanic edifice and a prominent zone of structural weakness, as expressed by lineaments, dikes, and brittle structures. For our data set, the volume changes estimated from the moments are � 200 m 3 for the largest explosion from each vent. Together with the volumetric source is a dominantly vertical force with a magnitude of 10 8 N, consistent with the inferred movement of the magma column perched above the source Centroid in response to the piston-like rise of a slug of gas in the conduit. INDEX TERMS: 7215 Seismology: Earthquake parameters; 7280 Seismology: Volcano seismology (8419); 8414 Volcanology: Eruption mechanisms; KEYWORDS: very-long-period seismicity, moment tensor inversions, eruption mehanics
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source mechanisms of explosions at stromboli volcano italy determined from moment tensor inversions of very long period data
Journal of Geophysical Research, 2003Co-Authors: Bernard Chouet, Takao Ohminato, M Martini, Gilberto Saccorotti, Flora Giudicepietro, Gaetano De Luca, G Milana, Phillip B Dawson, Roberto ScarpaAbstract:[1] Seismic data recorded in the 2–30 s band at Stromboli Volcano, Italy, are analyzed to quantify the source mechanisms of Strombolian explosions during September 1997. To determine the source-Centroid location and source mechanism, we minimize the residual error between data and synthetics calculated by the finite difference method for a point source embedded in a homogeneous elastic medium that takes topography into account. Two source Centroids are identified, each representative of the distinct event types associated with explosive eruptions from two different vents. The observed waveforms are well reproduced by our inversion, and the two source Centroids that best fit the data are offset 220 and 260 m beneath and � 160 m northwest of the active vents. The source mechanisms include both moment-tensor and single-force components. The principal axes of the moment tensor have amplitude ratios 1:1:2, which can be interpreted as representative of a crack, if one assumes the rock matrix at the source to have a Poisson ratio n = 1/3, a value appropriate for hot rock. Both imaged cracks dip � 60� to the northwest and strike northeast–southwest along a direction parallel to the elongation of the volcanic edifice and a prominent zone of structural weakness, as expressed by lineaments, dikes, and brittle structures. For our data set, the volume changes estimated from the moments are � 200 m 3 for the largest explosion from each vent. Together with the volumetric source is a dominantly vertical force with a magnitude of 10 8 N, consistent with the inferred movement of the magma column perched above the source Centroid in response to the piston-like rise of a slug of gas in the conduit. INDEX TERMS: 7215 Seismology: Earthquake parameters; 7280 Seismology: Volcano seismology (8419); 8414 Volcanology: Eruption mechanisms; KEYWORDS: very-long-period seismicity, moment tensor inversions, eruption mehanics
Jayme R Vianna - One of the best experts on this subject based on the ideXlab platform.
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oct optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch s membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Marcelo T Nicolela, Jayme R ViannaAbstract:Abstract Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to Bruch’s membrane opening (BMO) (ASCO/BMO offset) in order to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design: Cross-sectional study. Methods Using Optic Coherence Tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids, size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes, 264.3 ± 131.1 um; healthy controls, 89.0 ± 55.8 um, p Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
Michael J A Girard - One of the best experts on this subject based on the ideXlab platform.
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optical coherence tomography optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Ping Wei, Marcelo T NicolelaAbstract:Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to the Bruch membrane opening (BMO) (ASCO/BMO offset) to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design Cross-sectional study. Methods Using optical coherence tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids and size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes 264.3 ± 131.1 μm; healthy control subjects 89.0 ± 55.8 μm, P Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA, and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
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oct optic nerve head morphology in myopia i implications of anterior scleral canal opening versus bruch s membrane opening offset
American Journal of Ophthalmology, 2020Co-Authors: Jin Wook Jeoung, Seung Woo Hong, Christy Hardin, Stuart K. Gardiner, Hongli Yang, Yaxing Wang, Brad Fortune, Michael J A Girard, Marcelo T Nicolela, Jayme R ViannaAbstract:Abstract Purpose To measure the magnitude and direction of anterior scleral canal opening (ASCO) offset relative to Bruch’s membrane opening (BMO) (ASCO/BMO offset) in order to characterize neural canal obliqueness and minimum cross-sectional area (NCMCA) in 69 highly myopic and 138 healthy, age-matched, control eyes. Design: Cross-sectional study. Methods Using Optic Coherence Tomography (OCT) scans of the optic nerve head (ONH), BMO and ASCO were manually segmented and their Centroids, size and shape were calculated. ASCO/BMO offset magnitude and direction were measured after projecting the ASCO/BMO Centroid vector onto the BMO plane. Neural canal axis obliqueness was defined as the angle between the ASCO/BMO Centroid vector and the vector perpendicular to the BMO plane. NCMCA was defined by projecting BMO and ASCO points onto a plane perpendicular to the neural canal axis and measuring their overlapping area. Results ASCO/BMO offset magnitude was greater (highly myopic eyes, 264.3 ± 131.1 um; healthy controls, 89.0 ± 55.8 um, p Conclusions Our data suggest that increased temporal displacement of BMO relative to the ASCO, increased BMO and ASCO area, decreased NCMCA and increased neural canal obliqueness are characteristic components of ONH morphology in highly myopic eyes.
