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- Description:
- Classification of barrier island morphology stems from the seminal work of M. O. Hayes and others, which linked island shape to tidal range and wave height and defined coastal energy regimes (i.e., wave-dominated, mixed energy, tide-dominated). If true, this general relationship represents a process-based framework to link modern and ancient systems, and is key for determining paleomorphodynamic relationships. Here we present a new semi-global database of barrier islands and spits (n = 702). Shape parameters (aspect, circularity, and roundness) are used to quantify island boundary shape, and assess potential correlation with coastal energy regime using global wave and tide models. In adopting the original energy classification as originally put forth (i.e., wave dominated, wave-influenced mixed, tide-influenced mixed, tide dominated), results show that wave-dominated islands have statistically different mean shape values from those in the mixed energy fields, but the two mixed energy designations are not distinct from each other. Furthermore, each energy regime field contains a wide range of island shapes, with no clear trends present. Linear regression modeling shows that tidal range and wave height account for < 10% of the documented variance in island shape, a strong indication that other controls must be considered. Therefore, while energy regime distinctions can be used descriptively, their utility in predicting and constraining island shape is limited: barrier island shape is not indicative of coastal energy regime, and vice versa. Our analysis also demonstrates empirical scaling relationships among modern barrier islands for the first time, with implications for subsurface prediction. and This is the dataset of the Modern Barrier Island Database published in Mulhern et al., 2017 Marine Geology paper titled "Is Barrier Island Morphology a Function of Wave and Tide Regime?" with the DOI https://doi.org/10.1016/j.margeo.2017.02.016. If using this dataset please cite both the dataset and the paper.
- Keyword:
- paleomorphodynamic relationships, geology, barrier island, shallow marine, island shape, wave-dominated islands, shoreline morphology, Modern Barrier Island Database, and coastal geomorphology
- Subject:
- Geology
- Creator:
- Johnson, Cari L., Mulhern, Julia S., and Martin, John M.
- Owner:
- Julia Mulhern
- Language:
- English
- Date Uploaded:
- 09/08/2021
- Date Modified:
- 12/08/2023
- Date Created:
- 2015-01-01 to 2017-12-31
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-5pzj-r9vr
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- Description:
- We discuss a new set of ~ 500 numerical n-body calculations designed to constrain the masses and bulk densities of Styx, Nix, Kerberos, and Hydra. Comparisons of different techniques for deriving the semimajor axis and eccentricity of the four satellites favor methods relying on the theory of Lee & Peale (2006), where satellite orbits are derived in the context of the restricted three body problem (Pluto, Charon, and one massless satellite). In each simulation, we adopt the nominal satellite masses derived in Kenyon & Bromley (2019b), multiply the mass of at least one satellite by a numerical factor f >= 1, and establish whether the system ejects at least one satellite on a time scale <= 4.5~Gyr. When the total system mass is large (f >> 1), ejections of Kerberos are more common. Systems with lower satellite masses (f ~ 1) usually eject Styx. In these calculations, Styx often signals an ejection by moving to higher orbital inclination long before ejection; Kerberos rarely signals in a useful way. The n-body results suggest that Styx and Kerberos are more likely to have bulk densities comparable with water ice, rho_SK <= 2 g/cm^3, than with rock. A strong upper limit on the total system mass, M_SNKH <= 9.5 x 10^19 g, also places robust constraints on the average bulk density of the four satellites, rho_SNKH <= 1.4 g/cm^3. These limits support models where the satellites grow out of icy material ejected during a major impact on Pluto or Charon.
- Keyword:
- Nix, dynamic evolution, satellites , Hydra, Styx, Charon, model, Pluto, planets, and Kerberos
- Subject:
- Astrophysics
- Creator:
- Kenyon, Scott and Bromley, Benjamin
- Owner:
- BENJAMIN BROMLEY
- Based Near Label Tesim:
- United States, , United States
- Date Uploaded:
- 04/01/2022
- Date Modified:
- 12/06/2023
- Date Created:
- 2019-05-15 to 2022-03-25
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-5g6f-yfc5
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- Description:
- Ultralow-velocity zones (ULVZs) have been studied using a variety of seismic phases; however, their physical origin is still poorly understood. Short period ScP (S wave converted to, and reflected as, P wave from the core-mantle boundary) waveforms are extensively used to infer ULVZ properties because they may be sensitive to all ULVZ elastic moduli. However, ScP waveforms are additionally complicated by the effects of path attenuation, coherent noise, and source-time function (STF) complexity. To address these complications, we developed a hierarchical Bayesian inversion method that allows us to invert ScP waveforms from multiple events simultaneously and accounts for path attenuation and correlated noise. The inversion method is tested with synthetic predictions which show that the inclusion of attenuation is imperative to recover ULVZ parameters and that the ULVZ thickness and S-wave velocity decrease (δVS) are most reliably recovered. Utilizing multiple events reduces the effects of coherent noise and STF complexity, which in turns allows for the inclusion of more data to be used in the analyses. We next applied the method to ScP data recorded in Australia for 291 events that sample the CMB beneath the Coral Sea. Our results indicate that S-wave velocity across the region is ~-14% in average, but there is a greater variability in the south than that in the north. P-wave velocity reductions and density perturbations are mostly below 10%. These ScP data show more than one ScP post-cursor in some areas which may indicate complex 3-D ULVZ structures. Seismic data are provided for 291 earthquakes in Northern Territory, Australia.
- Keyword:
- seismology, mantel phases, ULVZ, and short period ScP waveforms
- Subject:
- Geology, Seismology, and Geophysics
- Creator:
- Pachhai, Surya and Thorne, Michael S.
- Owner:
- Surya Pachhai
- Based Near Label Tesim:
- Northern Territory, Northern Territory, Australia
- Language:
- English
- Date Uploaded:
- 12/10/2022
- Date Modified:
- 12/04/2023
- Date Created:
- 2005-01-01 to 2021-12-30.
- License:
- Public Domain – This data is free of copyright restrictions (e.g. government sponsored data).
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-a67s-y717
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Data for: Restitution Characteristics of His Bundle and Working Myocardium in Isolated Rabbit Hearts
- Description:
- The Purkinje system (PS) and the His bundle have been recently implicated as an important driver of the rapid activation rate after 1-2 minutes of ventricular fibrillation (VF). It is unknown whether activations during VF propagate through the His-Purkinje system to other portions of the the working myocardium (WM). Little is known about restitution characteristic differences between the His bundle and working myocardium at short cycle lengths. In this study, rabbit hearts (n=9) were isolated, Langendorff- perfused, and electromechanically uncoupled with blebbistatin (10 μM). Pacing pulses were delivered directly to the His bundle. By using standard glass microelectrodes, action potentials duration (APD) from the His bundle and WM were obtained simultaneously over a wide range of stimulation cycle lengths (CL). The global F-test indicated that the two restitution curves of the His bundle and the WM are statistically significantly different (P<0.05). Also, the APD of the His bundle was significantly shorter than that of WM throughout the whole pacing course (P<0.001). The CL at which alternans developed in the His bundle vs. the WM were shorter for the His bundle (134.2±13.1ms vs. 148.3±13.3ms, P<0.01) and 2:1 block developed at a shorter CL in the His bundle than in WM (130.0±10.0 vs. 145.6±14.2ms, P<0.01). The His bundle APD was significantly shorter than that of WM under both slow and rapid pacing rates, which suggest that there may be an excitable gap during VF and that the His bundle may conduct wavefronts from one bundle branch to the other at short cycle lengths and during VF.
- Keyword:
- ventricular fibrillation, action potential duration, cardiology, working myocardium, rabbit, restitution curve, alternans, His bundle, and microelectrode
- Subject:
- ventricular fibrillation, cardiology, and myocardium
- Creator:
- Huang, Shangwei, Panitchob, Nuttanont, Hu, Nan, Ranjan, Ravi, Huang, Liqun, and Dosdall, Derek
- Owner:
- BRIAN MCBRIDE
- Based Near Label Tesim:
- Salt Lake City, Utah, United States
- Language:
- English
- Date Uploaded:
- 07/10/2019
- Date Modified:
- 04/18/2024
- Date Created:
- 2016-03-21 to 2016-05-25
- License:
- CCO – As the data author, you are choosing to place your data into the public domain.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50R9MJX
-
- Description:
- -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: The data were generated by computer simulations using the C++ code "Orchestra", a proprietary hybrid code that follows the dynamical evolution of solids and gas orbiting a central object. Algorithms in the code are described in the following papers (author names abbreviated to B for Bromley, K for Kenyon, and L for Jane X Luu along with a year for publication date, AJ = Astronomical Journal, ApJ = Astrophysical Journal, S=Supplement): KL1998, AJ 115:2136; KL1999, AJ 118:1101; KB2001,AJ 121:538; KB2002,AJ 123:1757; KB2004, AJ 127:513; BK2006, AJ 131:2737; KB2006, AJ 131:1837; KB2008, ApJS 179:451; KB2010, ApJS 188:242; BK2011, ApJ 731:101; KB2012, AJ 143:63; KB2014, AJ 147:8. Initial conditions for these simulations described in the published paper. 2. Methods for processing the data: Various C and fortran programs are used to analyze the data for the calculations. Several C programs needed to extract information from the computer generated binary output files are included with the dataset. The C programs include basic summaries of the structure of the data files and the usage to extract data from each binary file. 3. Instrument- or software-specific information needed to interpret the data: Appropriate software is included in directory. 4. Standards and calibration information, if appropriate: none 5. Environmental/experimental conditions: all calculations were run on the NASA discover cluster 6. Describe any quality-assurance procedures performed on the data: Aside from tests summarized in the papers described in item 1, test calculations are summarized in the Appendix of each paper and compared to an appropriate benchmark. 7. People involved with sample collection, processing, analysis and/or submission: Scott Kenyon and Ben Bromley and --------------------- DATA & FILE OVERVIEW --------------------- Files summarized in items 1-8 are binary output files from n-body simulations as described in Kenyon & Bromley, "A Pluto-Charon Sonata: Dynamical Limits on fate Masses of the Small Satellites" (2019, Astronomical Journal). Files described in item 9 are ascii txt. The C programs in items 10, 11, and 12 provide different ways to access the binary output. Each C program describes the architecture of the binary files. 1. pcs2-0mmm-nnn[a-z] files: heavy satellites, mmm = 100 x mass factor for all satellites, nnn = number of Symplectic steps per PC orbit, a-z = version 2. pcs2-1mmm-nnn[a-z] files: light satellites, mmm = 100 x mass factor for all satellites, nnn = number of Symplectic steps per PC orbit, a-z = version 3. pcs2-2mmm-nnn[a-z] files: light satellites with 2x nominal mass of Styx & Kerberos, mmm = 100 x mass factor for all satellites, nnn = number of Symplectic steps per PC orbit, a-z = version 4. pcs2-3mmm: heavy satellites, 40 Symplectic steps per PC orbit, mmm = 100 x mass factor for Nix only 5. pcs2-4mmm: heavy satellites, 40 Symplectic steps per PC orbit, mmm = 100 x mass factor for Kerberos only 6. pcs2-5mmm: heavy satellites, 40 Symplectic steps per PC orbit, mmm = 100 x mass factor for Hydra only 7. pcs2-6mmm light satellites, 40 Symplectic steps per PC orbit, mmm = 100 x mass factor for Nix only 8. pcs2-7mmm: light satellites, 40 Symplectic steps per PC orbit, mmm = 100 x mass factor for Hydra only 9. pcs2-n000.dat: summary of lifetimes for binary files in each archive 10. lifetime.c: summarizes lifetime and mass factor for binary file usage example: "lifetime pcs2-6110" 11. summary.c: generates basic summary of timesteps in a binary file usage example: "summary pcs1-0013d" 12. extrxyz.c: extracts (x,y,z) for N satellites and outputs (x,y,z) usage example: "extr6d pcs1-6110 6" will output (x,y,z) for SNKH 3. Additional related data collected that was not included in the current data package: There are other binary output files not included in this archive. 4. Are there multiple versions of the dataset? no
- Subject:
- Astrophysics
- Creator:
- Bromley, Benjamin and Kenyon, Scott
- Depositor:
- BRIAN MCBRIDE
- Owner:
- BENJAMIN BROMLEY
- Language:
- English
- Date Uploaded:
- 07/11/2019
- Date Modified:
- 04/04/2022
- Date Created:
- 2018-2019
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50D-HAJT-E0G0
-
- Description:
- We analyzed 4,754 broadband seismic recordings of the SKS, SKKS, and SPdKS wavefield from 13 high quality events sampling the Samoa ultralow-velocity zone (ULVZ). We measured differential travel-times and amplitudes between the SKKS and SKS arrivals, which are highly sensitive to the emergence of the SPdKS seismic phase, which is in turn highly sensitive to lowermost mantle velocity perturbations such as generated by ULVZs. We modeled these data using a 2-D axi-symmetric waveform modeling approach and are able to explain these data with a single ULVZ. In order to predict both travel-time and amplitude perturbations we found that a large ULVZ length in the great circle arc direction on the order of 10° or larger is required. The large ULVZ length limits acceptable ULVZ elastic parameters. Here we find that δVS and δVP reductions from 20% to 22% and 15% to 17% respectively gives us the best fit, with a thickness of 26 km. Initial 3-D modeling efforts do not recover the extremes in the differential measurements, demonstrating that 3-D effects are important and must be considered in the future. However, the 3-D modeling is generally consistent with the velocity reductions recovered with the 2-D modeling. These velocity reductions are compatible with a compositional component to the ULVZ. Furthermore, geodynamic predictions for a compositional ULVZ that is moving predict a long linear shape similar to the shape of the Samoa ULVZ we confirm in this study. and This collection includes radial component displacement seismograms in the time window including the SKS, SKKS and SPdKS seismic arrivals. These data all interact with the Samoa ultra-low velocity zone at the core-mantle boundary. All data used in the study of Krier et al., 2021 (JGR) is included in this collection.
- Subject:
- Geology, seismology, and Geophysics
- Creator:
- Michael S. Thorne, Tarje Nissen-Meyer, Justin D. Krier, and Kuangdai Leng
- Owner:
- Michael Thorne
- Based Near Label Tesim:
- Tonga Trench, , Tonga
- Language:
- English
- Date Uploaded:
- 02/17/2021
- Date Modified:
- 12/09/2021
- Date Created:
- January 2019 to January 2020
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50DT3X22GGB
-
- Description:
- Ground-based measurements of frozen precipitation are heavily influenced by interactions of surface winds with gauge-shield geometry. The Multi-Angle Snowflake Camera (MASC), which photographs hydrometeors in free-fall from three different angles while simultaneously measuring their fall speed, has been used in the field at multiple mid-latitude and polar locations both with and without wind shielding. Here we present an analysis of Arctic field observations — with and without a Belfort double Alter shield — and compare the results to computational fluid dynamics (CFD) simulations of the airflow and corresponding particle trajectories around the unshielded MASC. MASC-measured fall speeds compare well with Ka-band Atmospheric Radiation Measurement (ARM) Zenith Radar (KAZR) mean Doppler velocities only when winds are light (< 5 m/s) and the MASC is shielded. MASC-measured fall speeds that do not match KAZR measured velocities tend to fall below a threshold value that increases approximately linearly with wind speed but is generally < 0.5 m/s. For those events with wind speeds < 1.5 m/s, hydrometeors fall with an orientation angle mode of 12 degrees from the horizontal plane, and large, low-density aggregates are as much as five times more likely to be observed. Simulations in the absence of a wind shield show a separation of flow at the upstream side of the instrument, with an upward velocity component just above the aperture, which decreases the mean particle fall speed by 55% (74%) for a wind speed of 5 m/s (10 m/s). We conclude that accurate MASC observations of the microphysical, orientation, and fall speed characteristics of snow particles require shielding by a double wind fence and restriction of analysis to events where winds are light (< 5 m/s). Hydrometeors do not generally fall in still air, so adjustments to these properties' distributions within natural turbulence remain to be determined.
- Subject:
- Meteorology and Atmospheric Science
- Creator:
- Talaei, Ahmad, Hang, Chaoxun, Fitch, Kyle E., and Garrett, Timothy J.
- Owner:
- Language:
- English
- Date Uploaded:
- 07/20/2020
- Date Modified:
- 12/14/2020
- Date Created:
- 20120521 to 20200719
- Resource Type:
- Software or Program Code
- Identifier:
- https://doi.org/10.7278/S50DQTX9K7QY
-
- Description:
- The data set includes individual images of mouse cochleae, both scanning electron micrographs and fluorescent micrographs, used to generate aggregated data described in Pecha PP, Almishaal AA, Mathur PD, et al. Role of Free Radical Formation in Murine Cytomegalovirus–Induced Hearing Loss. Otolaryngology–Head and Neck Surgery. 2020;162(5):709-717. doi:10.1177/0194599820901485 and Objectives The goal of the study was to determine whether reactive oxygen species (ROS) mediates cytomegalovirus (CMV)–induced labyrinthitis. Study Design Murine model of CMV infection. Subjects and Methods Nrf2 knockout mice were inoculated with murine CMV. Auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAEs) were then performed on these and uninfected controls. BALB/c mice were inoculated with murine CMV to determine whether a marker for ROS production, dihydroethidium (DHE), is expressed 7 days after inoculation. Finally, 2 antioxidants—D-methionine and ACE-Mg (vitamins A, C, and E with magnesium)—were administered 1 hour before and after infection in inoculated mice for 14 days. Temporal bones were harvested at postnatal day 10 for DHE detection. ABR and DPOAE testing was done at postnatal day 30. Scanning electron microscopy was also performed at postnatal day 30 to evaluate outer hair cell integrity. Results Nrf2-infected mice had worse hearing than uninfected mice (P < .001). A statistically significant increase in DHE fluorescence was detected in BALB/c-infected mice as compared with uninfected mice 7 days after inoculation. D-methionine- and ACE-Mg-treated mice demonstrated an attenuation of the DHE fluorescence and a significant improvement in ABR and DPOAE thresholds when compared with untreated infected controls (P < .0001). Scanning electron microscopy demonstrated less outer hair cell loss in the treated versus untreated infected controls. Conclusion These results demonstrate for the first time that excessive ROS mediates CMV-induced hearing loss in a mouse model.
- Creator:
- Firpo, Matthew A.
- Owner:
- BRIAN MCBRIDE
- Based Near Label Tesim:
- Salt Lake City, Utah, United States
- Language:
- English
- Date Uploaded:
- 07/10/2019
- Date Modified:
- 01/28/2022
- Date Created:
- 04082015-11022016
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50D-D0WT-SV00