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- Creator:
- Tye, Alexander R, Wolf, Aaron S, and Niemi, Nathan A
- Description:
- Detrital zircon age distributions provide robust insights into past sedimentary systems, but these age distributions are often complex and multi-peaked, with sample sizes too small to confidently resolve population distributions. This limited sampling hinders existing quantitative methods for comparing detrital zircon age distributions, which show systematic dependence on the sizes of compared samples. The proliferation of detrital zircon studies motivates the development of more robust quantitative methods. We present the first attempt, to our knowledge, to infer probability model ensembles (PMEs) for samples of detrital zircon ages using a Bayesian method. Our method infers the parent population age distribution from which a sample is drawn, using a Monte Carlo approach to aggregate a representative set of probability models that is consistent with the constraints that the sample data provide. Using the PMEs inferred from sample data, we develop a new estimate of correspondence between detrital zircon populations called Bayesian Population Correlation (BPC). Tests of BPC on synthetic and real detrital zircon age data show that it is nearly independent from sample size bias, unlike existing correspondence metrics. Robust BPC uncertainties can be readily estimated, enhancing interpretive value. When comparing two partially overlapping zircon age populations where the shared proportion of each population is independently varied, BPC results conform almost perfectly to expected values derived analytically from probability theory. This conformity of experimental and analytical results permits direct inference of the shared proportions of two detrital zircon age populations from BPC. We provide MATLAB scripts to facilitate the procedures we describe.
- Keyword:
- provenance, statistics, zircon, Bayesian, detrital, and density estimation
- Citation to related publication:
- A.R. Tye, A.S. Wolf, N.A. Niemi, Bayesian population correlation: A probabilistic approach to inferring and comparing population distributions for detrital zircon ages, Chemical Geology, Volume 518, 2019, Pages 67-78, ISSN 0009-2541, https://doi.org/10.1016/j.chemgeo.2019.03.039
- Discipline:
- Science
-
- Creator:
- Azari, A. R.
- Description:
- ABSTRACT: We present a statistical study of interchange injections in Saturn's inner and middle magnetosphere focusing on the dependence of occurrence rate and properties on radial distance, partial pressure, and local time distribution. Events are evaluated from over the entirety of the Cassini mission’s equatorial orbits between 2005 and 2016. We identified interchange events from CHarge Energy Mass Spectrometer (CHEMS) H+ data using a trained and tested automated algorithm, which has been compared with manual event identification for optimization. We provide estimates of interchange based on intensity, which we use to investigate current inconsistencies in local time occurrence rates. This represents the first automated detection method of interchange, estimation of injection event intensity, and comparison between interchange injection survey results. We find the peak rates of interchange occur between 7 - 9 Saturn radii and that this range coincides with the most intense events as defined by H+ partial particle pressure. We determine that nightside occurrence dominates as compared to the dayside injection rate, supporting the hypothesis of an inversely dependent instability growth rate on local Pedersen ionospheric conductivity. Additionally, we observe a slight preference for intense events on the dawn side, supporting a triggering mechanism related to large-scale injections from downtail reconnection. Our observed local time dependence paints a dynamic picture of interchange triggering due to both the large-scale injection driven process and ionospheric conductivity. Within this repository we provide a readme file (description of data file and usage) and the event list provided as a .txt file. The event list includes start and stop times, comparison to previous surveys, and the average location of events identified. Additional formats are available on request. , Further details on this method can be found in "Interchange Injections at Saturn: Statistical Survey of Energetic H+ Sudden Flux Intensifications" by Azari et al., 2018 in the Journal of Geophysical Research: Space Physics. https://doi.org/10.1029/2018JA025391. , and Curation notes: The files 'events_CORRECTED.txt' and 'readme_UPDATED.rtf' were added to this record July 31 and August 7, 2018 and supersede the previous data file 'events.txt' and readme file 'readme.rtf'. The file 'events.txt' uploaded May 9, 2018 should not be used, as this file contains a duplication error where the last column, InAllSurveys, is incorrectly presented as a duplicate of the column InAnySurvey. 'readme_UPDATED.rtf' contains additional context and updated references to the new data file.
- Keyword:
- Planetary Science, Automated Event Detection, Space Physics, Magnetospheric Physics, Interchange Injections, and Saturn
- Discipline:
- Science
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- Creator:
- Mason, Lacey A., Riseng, Catherine M., Layman, Andrew J., and Jensen, Robert
- Description:
- Wind exposure is a key physical driver of coastal systems in aquatic environments influencing circulation and wave dynamics. A measure of wind exposure is fetch, the distance over which wind can travel across open water. In large lake systems, such as the Laurentian Great Lakes, estimating fetch has proved to be difficult due to their vast size and complex topobathymetry. Here we describe the development of two spatially discrete indicators of exposure to provide a more accurate indicator of influence of wind exposure in the nearshore of the Laurentian Great Lakes. We summarized wind data from offshore buoys and leveraged existing tools to calculate effective fetch and relative exposure index (effective fetch scaled by mean wind speed) at a 30 m grid cell resolution. We validated these models by comparing our exposure maps to the U.S. Army Corps of Engineers Wave Information Studies models and found general agreement. These exposure maps are available for public download for the years 2004-2014.
- Keyword:
- GLAHF, Great Lakes, waves, fetch, REI, wind exposure, and geospatial
- Discipline:
- Science
-
- Creator:
- Cole, Shannon L
- Description:
- The nucleus accumbens (NAc) contains multiple subpopulations of medium spiny neurons (MSNs): one subpopulation expresses D1-type dopamine receptors, another expresses D2-type receptors, and a third expresses both. The relative roles in NAc of D1 neurons versus D2 neurons in appetitive motivation were assessed here. Specifically, we asked whether D1-Cre mice or D2-Cre mice would instrumentally seek optogenetic self-stimulation of those respective subpopulations in NAc, or instead avoid NAc laser stimulation. and Some statistical forms have been exported from SPSS for the purposes of accessibility to viewers. Please see the "readme" text for descriptions of each individual excel file.
- Keyword:
- Motivation Striatum Optogenetics
- Citation to related publication:
- Cole, S. L., Robinson, M. J. F., & Berridge, K. C. (2018). Optogenetic self-stimulation in the nucleus accumbens: D1 reward versus D2 ambivalence. PLOS ONE, 13(11), e0207694. https://doi.org/10.1371/journal.pone.0207694
- Discipline:
- Science
-
- Creator:
- Gliske, Stephen V and Stacey, William C
- Description:
- This data is part of a large program to translate detection and interpretation of HFOs into clinical use. A zip file is included which contains hfo detections, metadata, and Matlab scripts. The matlab scripts analyze this input data and produce figures as in the referenced paper (note: the blind source separation method is stochastic, and so the figures may not be exactly the same). A file "README.txt" provides more detail about each individual file within the zip file.
- Keyword:
- hfo, high frequency oscillation, ripple, fast ripple, blind source separation, non-negative matrix factorization, and temporal variability
- Discipline:
- Science, Engineering, and Health Sciences
-
- Creator:
- Ward, Jamie L ., Flanner, Mark G., Bergin, Mike, Dibb, Jack E., Polashenski, Chris M., Soja, Amber J., and Thomas, Jennie L.
- Description:
- Biomass burning produces smoke aerosols that are emitted into the atmosphere. Some smoke constituents, notably black carbon (BC), are highly effective light-absorbing aerosols (LAA). Emitted LAA can be transported to high albedo regions like the Greenland Ice Sheet (GrIS) and affect local snowmelt. In the summer, the effects of LAA in Greenland are uncertain. To explore how LAA affect GrIS snowmelt and surface energy flux in the summer, we conduct idealized global climate model simulations with perturbed aerosol amounts and properties in the GrIS snow and overlying atmosphere. The in-snow and atmospheric aerosol burdens we select range from background values measured on the GrIS to unrealistically high values. This helps us explore the linearity of snowmelt response and to achieve high signal-to-noise ratios. With LAA operating only in the atmosphere, we find no significant change in snowmelt due to the competing effects of surface dimming and tropospheric warming. Regardless of atmospheric LAA presence, in-snow BC-equivalent mixing ratios greater than ~60 ng/g produce statistically significant snowmelt increases over much of the GrIS. We find that net surface energy flux changes correspond well to snowmelt changes for all cases. The dominant component of surface energy flux change is solar energy flux, but sensible and longwave energy fluxes respond to temperature changes. Atmospheric LAA dampen the magnitude of solar radiation absorbed by in-snow LAA when both varieties are simulated. In general, the significant melt and surface energy flux changes we simulate occur with LAA quantities that have never been recorded in Greenland.
- Keyword:
- climate, Greenland Ice Sheet, black carbon, biomass burning, snowmelt, and surface energy balance
- Citation to related publication:
- Ward, J.L., et al. (2018). Modeled Response of Greenland Snowmelt to the Presence of Biomass Burning-Based Absorbing Aerosols in the Atmosphere and Snow. Journal of Geophysical Research: Atmospheres. 123, 6122– 6141. https://doi.org/10.1029/2017JD027878
- Discipline:
- Science
-
- Creator:
- Bemmels, Jordan B. and Dick, Christopher W.
- Description:
- Raw SNP genotypes are provided in STRUCTURE format, with a maximum of one SNP reported per ddRAD locus. The files "caryco_SNP.str" and "caryov_SNP.str" are genotypes for Carya cordiformis and Carya ovata, respectively. The first column of each file is the individual name, the second column is the population (see original publication for information on population locations), and the remaining columns are genotypes of individual SNPs. Rows represent individuals, with the diploid genotypes contained on two lines per individual. Missing data are entered as "0" (zero). The first row is a header with a unique identifier for each SNP. and Occurrence records for each species are provided in the file "occs_carya.csv" and contain the latitude and longitude of each record.
- Keyword:
- eastern North America, glacial refugia, phylogeography, temperate trees, and single nucleotide polymorphisms
- Citation to related publication:
- Bemmels, J.B., and C.W. Dick. 2018. Genomic evidence of a widespread southern distribution during the Last Glacial Maximum for two North American hickory species. Journal of Biogeography, 45: 1739– 1750. https://doi.org/10.1111/jbi.13358
- Discipline:
- Science
-
- Creator:
- Mirshams Shahshahani, Payam
- Description:
- Investigating minimum human reaction times is often confounded by the motivation, training, and state of arousal of the subjects. We used the reaction times of athletes competing in the shorter sprint events in the Athletics competitions in recent Olympics (2004-2016) to determine minimum human reaction times because there's little question as to their motivation, training, or state of arousal. The reaction times of sprinters however are only available on the IAAF web page for each individual heat, in each event, at each Olympic. Therefore we compiled all these data into two separate excel sheets which can be used for further analyses.
- Keyword:
- minimum reaction time, sprinter, Olympics, Athletics, sex difference, starting block, and false start
- Citation to related publication:
- Mirshams Shahshahani P, Lipps DB, Galecki AT, Ashton-Miller JA (2018) On the apparent decrease in Olympic sprinter reaction times. PLoS ONE 13(6): e0198633. https://doi.org/10.1371/journal.pone.0198633
- Discipline:
- Engineering, Health Sciences, Science, Other, and General Information Sources
-
- Creator:
- Adam Schneider and Mark Flanner
- Description:
- This dataset contains all data used to generate the figures in The Cryosphere manuscript “Measuring Snow Specific Surface Area with 1.30 and 1.55 micro-meter Bidirectional Reflectance Factors,” by Adam Schneider, Mark Flanner, and Roger De Roo. These data support the theory, calibration, and application of the Near-Infrared Emitting and Reflectance Monitoring Dome (NERD), an instrument engineered to rapidly retrieve surface snow specific surface area in the field. Note that this deposit includes a microCT scan database for natural snowfall samples collected in New Hampshire during 2015-2017, comprised of raw tiff files as well as reconstructions, binarized reconstructions, and some 3D model reconstructions. and Running python scripts generally require that the following packages are installed: NumPy, SciPy, Matplotlib, Pandas, and ipdb (for debugging).
- Keyword:
- Snow specific surface area, Monte Carlo, X-ray micro-computed tomography, SNICAR, Near-Infrared Emitting and Reflectance-Monitoring Dome, Bidirectional reflectance factor, Cryosphere, and 3D
- Discipline:
- Science
-
- Creator:
- Alsip, Peter
- Description:
- Percent Weight Change Data: The model was run continuously on a daily time step for seasonal intervals (Spring: March thru May; Summer: June thru August; Fall: September thru November) as well as contiguously from Spring to Fall to assess total growth over the likely growing season (March thru November). CSV files represent the simulated weight change (%) of Bighead and Silver Carp for the respective time periods associated with the file name. Initial fish mass for each seasonal interval and growing season was 4350 g for Silver Carp and 5480 g for Bighead Carp. Maximum and mean total weight change (%) was determined for three depth ranges (near surface depths [NS]: 0 – 10 m; deep chlorophyll layer depths [DCL]: 10 - 50 m; and whole water column [WC]). Coordinates are in decimal degrees. File naming convention: speciesSeasonWtChange (e.g. bigheadFallWtChange = % weight change of Bighead Carp from September through November) , Monthly Habitat Quality Data: Rdata files contain matrices of Bighead or Silver carp growth rate potential as represented as a mass-proportional growth rate (gram of carp/gram of carp/day [g/g/d]) for the 15th day of each month. Habitats with growth rate potential >= 0 g/g/d were deemed suitable. Matrix attributes: Rows: Row numbers refer to the spatial node with 20 equally-spaced vertical layers. Columns: Columns 1-20 refer to the growth rate potential value for each vertical layer of each node. Vertical layers are evenly spaced based on the total depth of the water column for each node. Depth for each node can be found in the grid attributes data file. Columns 21 ("meanG") and 22 ("Gmax") represent the average and maximum growth rate potential, respectively, of the fish across the whole water column for the corresponding node. File naming convention: species_MonthNumber (e.g. silver_06 = Silver carp growth rate potential in June) Spatial coordinates for each node can be found in the grid attributes data files., Grid attributes data: This Rdata file provides the spatial reference data and other grid attributes. Coordinates are provided in UTM (x & y) and latitude and longitude (decimal degrees). Depth (meters) for each node is listed in this file. , GRP Model code: Details bioenergetics equations, foraging equation, functions for running the model on a monthly time-step and daily time step, and functions for basic analyses. Model is coded in R., and The simulated input data (prey and temperature) used to run our model is not included in this data set. Instead we provide the model code, grid attributes, and outputs of the model. The readRDS() function (R Base Package v.3.5.1) is required to read in .Rdata files in R.
- Keyword:
- Asian Carp, Laurentian Great Lakes, Habitat Suitability, Invasive Species, Lake Michigan, and Ecological Modeling
- Discipline:
- Science