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- Creator:
- McCuen, Brett A.
- Description:
- We present a comprehensive statistical analysis of high-frequency transient-large-amplitude (TLA) magnetic perturbation events that occurred at 12 high-latitude ground magnetometer stations throughout solar cycle 24 from 2009 to 2019. TLA signatures are defined as one or more second-timescale dB/dt interval with magnitude ≥ 6 nT/s within an hour event window. This study characterizes high-frequency TLA events based on their spatial and temporal behavior as well as relation to auroral substorms, geomagnetic storm phases and nighttime geomagnetic disturbance events events (GMD). We show that TLA events occur primarily at nighttime and solely in the high-latitude region above 60 degrees geomagnetic latitude. The largest TLA events occurred more often in the declining phase of the solar cycle when solar wind velocity was higher and ring current activity was lower, suggesting association to high-speed flows caused by coronal holes and subsequent corotating interaction regions reaching Earth. TLA perturbations often occurred preceding or within the most extreme nighttime geomagnetic disturbance (GMD) events with 5-10 minute timescales, but the TLA intervals were often even more localized than the ~300 km effective radius of GMDs: occurring at only some of the stations at which GMDs occurred. We show that TLA-related GMD events can result from dipolarization fronts in the magnetotail and fast flows toward Earth and are closely temporally associated to poleward boundary intensifications (PBI) and auroral streamers. The highly localized behavior and connection to the most extreme GMD events suggests that TLA intervals are a ground manifestation of the features within rapid and complex ionospheric structures that can drive GICs.
- Keyword:
- geomagnetic field, high frequency, space weather, transient-large-amplitude, TLA, high frequency dB/dt, dB/dt search algorithm
- Citation to related publication:
- McCuen, B. A., Moldwin, M. B., Engebretson, M. J., Weygand, J. G., Nishimura, Y. (2023). A Statistical Analysis of High-frequency Transient-Large-Amplitude Geomagnetic Disturbance. [To be submitted to] Journal of Geophysical Research: Space Physics
- Discipline:
- Science
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- Creator:
- University of Michigan Museum of Paleontology and CTEES
- Description:
- Reconstructed CT slices for tooth in bone fragment of Colognathus obscurus (University of Michigan Museum of Paleontology catalog number UMMP 7506) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
- Keyword:
- Paleontology, Fossil, CT, Reptile, UMMP, University of Michigan Museum of Paleontology, Triassic, and bf7ead64-3fff-a3f2-6b15-d04548dae2da
- Discipline:
- Science
-
- Creator:
- Al Shidi, Qusai. and Pulkkinen, Tuija.
- Description:
- This is part of the simulation set of geomagnetic storms from 2010 to 2019. The Space Weather Modeling Framework (SWMF) with the configuration of SWPC v2 was used. The output files can be read by the visualization scripts included in the SWMF or the SpacePy Python package.
- Keyword:
- space weather, space physics, geomagnetic storms, and magnetosphere
- Discipline:
- Science
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- Creator:
- Umaña, Maria, Swenson, Nathan G, and Arellano, Gabriel
- Description:
- Identifying the functional traits that enable recovery after extreme events is necessary for assessing forest persistence and functioning, yet this is a difficult task because the traits mediating the responses to disturbance may vary depending on the disturbance type and over time. This study investigates the effects of traits on tree growth –for short and longer terms– in response to two vastly different extreme climatic events, droughts, and hurricanes, in a Puerto Rican forest.
- Keyword:
- Tropical tree, relative growth rates , and Puerto Rico
- Citation to related publication:
- Umaña, M. N. In review. The interplay of drought and hurricanes on tree recovery: insights from dynamic and weak functional responses. Forthcoming and Umana, M. (2023). Functional trait data across an elevational gradient of six tree species in El Yunque National Park, Puerto Rico in 2015 [Data set], University of Michigan - Deep Blue Data. https://doi.org/10.7302/7962-4t98
- Discipline:
- Science
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- Creator:
- Ludlow, Andrew and Kim, Jeongjin
- Description:
- Part of the regulation of telomerase activity includes the alternative splicing (AS) of the catalytic subunit telomerase reverse transcriptase (TERT). Although a therapeutic window for telomerase/TERT inhibition exists between cancer cells and somatic cells, stem cells express TERT and rely on telomerase activity for physiological replacement of cells. Therefore, identifying differences in TERT regulation between stem cells and cancer cells is essential for developing telomerase inhibition-based cancer therapies that reduce damage to stem cells. In this study, we measured TERT splice variant expression and telomerase activity in induced pluripotent stem cells (iPSCs), neural progenitor cells (NPCs), and non-small cell lung cancer cells (NSCLC, Calu-6 cells). We observed that a NOVA1-PTBP1-PTBP2 axis regulates TERT alternative splicing (AS) in iPSCs and their differentiation into NPCs. We also found that splice-switching of TERT, which regulates telomerase activity, is induced by different cell densities in stem cells but not cancer cells. Lastly, we identified cell type-specific splicing factors that regulate TERT AS. Overall, our findings represent an important step forward in understanding the regulation of TERT AS in stem cells and cancer cells. These data and subsequent studies may reveal a splicing factor(s) or their binding site(s) that could be targeted with small molecule drugs or antisense oligonucleotides, respectively, to reduce telomerase activity in cancer cells and promote durable cancer remissions.
- Keyword:
- Telomere, telomerase, TERT, alternative RNA splicing
- Citation to related publication:
- Dynamics of TERT Regulation via Alternative Splicing in Stem Cells and Cancer Cells. Accepted in Plos One
- Discipline:
- Science
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- Creator:
- Martin, Tara L, Young, LR, Goldsteen, D, Nunamaker, EA, Reynolds, P, Thompson-Iritani, S, Thurston, SE, and LaFollette, MR
- Description:
- This dataset contains the results of a survey of mouse handling methods by personnel working with laboratory mice. The survey included questions about preferred handling methods, barriers to use of refined handling methods, and a knowledge quiz about refined mouse handling. Data was collected via Qualtrics survey as described in the methodology section. This dataset is associated with the following publication, accepted by PLOS One: PONE-D-23-01633R1 Title: Using refined methods to pick up mice: A survey benchmarking prevalence & beliefs about tunnel and cup handling Authors: Lauren Young, Donna Goldsteen, Elizabeth A. Nunamaker, Mark J. Prescott, Penny Reynolds, Sally Thompson-Iritani, Sarah E. Thurston, Tara L. Martin, Megan R. LaFollette
- Keyword:
- Mouse, Refined Handling, Tunnel Handling, Cup Handling, Laboratory Animal, and Animal Care
- Citation to related publication:
- Young LR, Goldsteen D, Nunamaker EA, Prescott MJ, Reynolds P, Thompson-Iritani S, Thurston SE, Martin TL, LaFollette MR. Using refined methods to pick up mice: A survey benchmarking prevalence & beliefs about tunnel and cup handling. PLOS ONE. 2023. In Press.
- Discipline:
- Science
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- Creator:
- Matt, Cayenne, Gültekin, Kayhan, and Simon, Joseph
- Description:
- The data were used to create number density functions of supermassive black holes (SMBH) for redshifts 0.5 < z < 3.0. The goal of this research is to discern whether galaxy-black hole scaling relations produce black hole masses that are consistent with each other at high redshift. These number density functions were used to compare the high-mass SMBH distributions from each relation. In massive black hole binary based models, the highest-mass SMBHs have a significant influence on the gravitational wave background characteristic strain amplitude. To inform our understanding of the gravitational wave background, that pulsar timing arrays now show evidence for, we need to therefore have a solid foundation on the underlying SMBH population. In our paper we found that using different galaxy properties to inform our estimations of SMBH mass resulted in different distributions, especially at the high-mass end.
- Citation to related publication:
- https://iopscience.iop.org/article/10.1088/0067-0049/219/1/8, https://iopscience.iop.org/article/10.1088/0067-0049/196/1/11, https://iopscience.iop.org/article/10.1088/0004-637X/788/1/28, https://iopscience.iop.org/article/10.3847/1538-4357/ab7e27, and https://ui.adsabs.harvard.edu/abs/2023arXiv230704878M/abstract
- Discipline:
- Science
-
- Creator:
- Lojko, Alexander, Zhang, Yingxiao, Whitcomb, Morgan, Yang, Emily, Dacic, Natasha, and Holmes, Janelle
- Description:
- GIS (.lpkx) data layers that inform of areas to construct new rain gardens in Washtenaw County, Ann Arbor, Michigan. Data layers can be opened with a GIS program. There is a single .lpkx dataset that contains four layers. The first layer contains 'Wildlife Corridors' which contains information on where to prioritize new green infrastructure based on how well-connected different patches of forested areas are. The second layer, 'Social Inequality', shows where to prioritize new rain gardens based on social inequality criteria. The 'Creeksheds and Future Runoff' contains information on future changes in precipitation runoff based on climate change projections of rainfall. Lastly, 'Runoff/Water Quality' is a layer that includes a priority map regarding where new rain gardens should be developed based on areas that are most at risk of poor water quality and enhanced surface run-off. The project was completed for Washtenaw County Water Resources as part of a course taught at the University of Michigan, CLIMATE 592. A description of the course is also provided: "Introduction to individual and team research on real-world problems in the area of applied climate. On a research project started in CLIMATE 591 and guided by a mentor from a commercial or government laboratory, students will apply the principles of risk analysis and objective assessment of adaptive strategies".
- Keyword:
- GIS, Climate Change, Local, Community, and Graduate Student Project
- Citation to related publication:
- Dacic, N., Lojko, A., Zhang, Y., Yang, E., Whitcomb, M., Bassis, J., and Rood., R.B., 2023 'Modernizing the Climate Science Curriculum: Engaging in Local Government Collaboration Projects', In Preperation for the Bulletin of American Meteorological Society
- Discipline:
- Science
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- Creator:
- Dewey, Ryan M, Livi, Stefano, Lepri, Susan T, Raines, Jim M, Ploof, Keeling, and The HIS Science Team
- Description:
- The data contained within the archive are for analysis and replication of Figure 2 in Livi et al. (2023), First Results from the Solar Orbiter Heavy Ion Sensor, Astronomy & Astrophysics. The readme.txt file contains more details on the contents of the archive and its files. Livi et al. (2023) reports the first solar wind composition measurements collected from the Heavy Ion Sensor (HIS) on the Solar Orbiter spacecraft. The period of study spans January-June 2022 during with the spacecraft completed nearly a full orbit about the Sun, from 0.3 AU to 1.0 AU. The solar wind composition within this publication are the first within the inner heliosphere. This paper describes the data and its processing from raw measurements (e.g., the data contained within this archive) to derived composition data products, and examines these composition data products about an interplanetary shock and interplanetary coronal mass ejection. Finally, these composition data are examined statistically and compared to historical data sets.
- Keyword:
- Solar Orbiter, Solar wind, Heavy ions, and Heavy Ion Sensor
- Citation to related publication:
- Livi, S., et al. (2023), First Results from the Solar Orbiter Heavy Ion Sensor, Astronomy & Astrophysics. https://doi.org/10.1051/0004-6361/202346304 and Owen, C., et al. (2020), The Solar Orbiter Solar Wind Analyser (SWA) suite, Astronomy & Astrophysics, 642. https://doi.org/10.1051/0004-6361/201937259
- Discipline:
- Science
-
- Creator:
- Thompson, Ellen P. and Ellis, Brian R.
- Description:
- Accurate prediction of physical alterations in carbonate reservoirs under dissolution is critical for development of subsurface energy technologies. The impact of mineral dissolution on flow characteristics depends on the connectivity and tortuosity of the pore network. Persistent homology is a tool from algebraic topology that describes the size and connectivity of topological features. When applied to 3D X-ray computed tomography (XCT) imagery of rock cores, it provides a novel metric of pore network heterogeneity. Prior works have demonstrated the efficacy of persistent homology in predicting flow properties in numerical simulations of flow through porous media. Its ability to combine size, spatial distribution, and connectivity information make it a promising tool for understanding reactive transport in complex pore networks, yet limited work has been done to apply persistence analysis to experimental studies on natural rocks. In this study, three limestone cores were imaged by XCT before and after acid-driven dissolution flow through experiments. Each XCT scan was analyzed using persistent homology. In all three rocks, permeability increase was driven by the growth of large, connected pore bodies. The two most homogenous samples saw an increased effect nearer to the flow inlet, suggesting emerging preferential flow paths as the reaction front progresses. The most heterogeneous sample showed an increase in along-core homogeneity during reaction. Variability of persistence showed moderate positive correlation with pore body size increase. Persistence heterogeneity analysis could be used to anticipate where greatest pore size evolution may occur in a reservoir targeted for subsurface development, improving confidence in project viability.
- Keyword:
- Carbonate dissolution, X-ray computed tomography, Porous media, Topology, and Persistent homology
- Citation to related publication:
- Thompson, E.P.; Ellis, B.R. (2023) Persistent Homology as a Heterogeneity Metric for Predicting Pore Size Change in Dissolving Carbonates. In Review.
- Discipline:
- Science and Engineering