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- Creator:
- Hoffmann, Alex P.
- Description:
- Research Overview: In situ magnetic field measurements are often difficult to obtain due to the presence of stray magnetic fields generated by spacecraft electrical subsystems. The conventional solution is to implement strict magnetic cleanliness requirements and place magnetometers on a deployable boom. However, this method is not always feasible on low-cost platforms due to factors such as increased design complexity, increased cost, and volume limitations. To overcome this problem, we propose using the Quad-Mag CubeSat magnetometer with an improved Underdetermined Blind Source Separation (UBSS) noise removal algorithm. The Quad-Mag consists of four magnetometer sensors in a single CubeSat form-factor card that allows distributed measurements of stray magnetic fields. The UBSS algorithm can remove stray magnetic fields without prior knowledge of the magnitude, orientation, or number of noise sources. UBSS is a two-stage algorithm that identifies signals through cluster analysis and separates them through compressive sensing. We use UBSS with single source point (SSP) detection to improve the identification of noise signals and iteratively-weighted compressed sensing to separate noise signals from the ambient magnetic field. Using a mock CubeSat, we demonstrate in the lab that UBSS reduces four noise signals producing more than 100 nT of noise at each magnetometer to below the expected instrument resolution (near 5 nT). Additionally, we show that the integrated Quad-Mag and improved UBSS system works well for 1U, 2U, 3U, and 6U CubeSats in simulation. Our results show that the Quad-Mag and UBSS noise cancellation package enables high-fidelity magnetic field measurements from a CubeSat without a boom.
- Keyword:
- source separation, demixing, magnetometers, stray magnetic fields, noise removal, and cubesat
- Citation to related publication:
- Hoffmann, A. P., Moldwin, M. B., Strabel, B. P., & Ojeda, L. V. (2023). Enabling Boomless CubeSat Magnetic Field Measurements with the Quad-Mag Magnetometer and an Improved Underdetermined Blind Source Separation Algorithm. Journal of Geophysical Research: Space Physics, 128, e2023JA031662. https://doi-org.proxy.lib.umich.edu/10.1029/2023JA031662
- Discipline:
- Engineering
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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:
- Brennan, Jonathan R.
- Description:
- These files contain the raw data and processing parameters to go with the paper "Hierarchical structure guides rapid linguistic predictions during naturalistic listening" by Jonathan R. Brennan and John T. Hale. These files include the stimulus (wav files), raw data (matlab format for the Fieldtrip toolbox), data processing paramters (matlab), and variables used to align the stimuli with the EEG data and for the statistical analyses reported in the paper.
- Keyword:
- linguistics, syntax, language, and eeg
- Citation to related publication:
- Brennan JR, Hale JT (2019) Hierarchical structure guides rapid linguistic predictions during naturalistic listening. PLoS ONE 14(1): e0207741. https://doi.org/10.1371/journal.pone.0207741
- Discipline:
- Social Sciences
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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
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- 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:
- Lumeng, Julie C
- Description:
- Healthy full-term infants were enrolled in a longitudinal study designed to examine the development of infant eating behavior. Infant weight and length was measured, mothers completed questionnaires regarding infant eating behaviors, and infants were weighed and length measured at ages 1, 2, 4, 6 and 10 months. Trajectories of eating behaviors were identified using latent class growth modeling and bivariate analyses examined associations of infant eating behavior trajectory membership with infant and maternal characteristics. Cross-lagged analyses examined associations between BEBQ subscales and infant weight-for-length z-score.
- Keyword:
- infant, eating, weight gain, and feeding
- Citation to related publication:
- Harlan McCaffery, Julie Zaituna, Sophie Busch, Niko Kaciroti, Alison L. Miller, Julie C. Lumeng, Katherine L. Rosenblum, Ashley Gearhardt, Megan H. Pesch, Developmental trajectories of eating behaviors and cross-lagged associations with weight across infancy, Appetite, 2023, 106978
- Discipline:
- Health Sciences
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- Creator:
- Rivera-Rivera, Luis Y., Moore, Timothy C., and Glotzer, Sharon C.
- Description:
- The dataset is organized as follows: the data for each of the three target structures is contained within a directory with the structure name (e.g., kagome, pyrocholore and snub-square). Within each structure directory, data obtained from alchemical and self-assembly simulations are separated into alchem and self-assembly directories respectively. An additional suboptimal-self-assembly directory is only present for the snub-square structure and contains the data for the pattern registration analysis discussed in the SI. For a detailed description of each file contained within each directory, please refer to the README file.
- Keyword:
- inverse design, self-assembly, triblock Janus particles, crystallization slot, and digital alchemy
- Citation to related publication:
- Rivera-Rivera, LY, Moore, TC & SC Glotzer. Inverse design of triblock Janus spheres for self-assembly of complex structures in the crystallization slot via digital alchemy. Soft Matter, 2023, 19, 2726-2736 doi: 10.1039/d2sm01593e
- Discipline:
- Engineering
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- Creator:
- Chenevert, Thomas L., Malyarenko, Dariya, Amouzandeh, Ghoncheh, Pickup, Stephen, Zhou, Rong, Manning, Henry Charles, Gamon, Seth T., Shoghi, Kooresh I., Quirk, James D., Sriram, Renuka, Larson, Peder, Lewis, Mickael T., Pautler, Robia G., Kinahan, Paul E., and Muzi, Mark
- Description:
- Goals of this work quantify repeatability and reproducibility across multiple NIH/NCI Co-Clinical Imaging Research Resources Program (CIRP) preclinical MRI systems in performing diffusion measurement using a standardized acquisition protocol on a shared phantom containing temperature-controlled medium of known diffusivity. To achieve these goals, the CIRP Image Acquisition Data Processing (IADP) working group (WG) performed a round-robin study of an ice water-based DWI phantom using a detailed phantom preparation procedure and standardized DWI acquisition protocol, with both site- and core-lab generated ADC measurements derived from shared datasets.
- Keyword:
- diffusion MRI, pre-clinical MRI, apparent diffusion coefficient (ADC), repeatability, reproducibility, and accuracy
- Citation to related publication:
- Tomography 2023, 9, 375–386. https://doi.org/10.3390/tomography9010030
- Discipline:
- Health Sciences
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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