Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
29,897
datasets available to search
ShareScore release 0.9.0
Dataset results
29,897 results for “activism”
Co-exposure of uranyl acetate and sodium arsenite differentially alters gene expression in CD3/CD28 activated CD4+ T-cells.
Communities in the western region of the United States experience environmental exposure to metal mixtures from living in proximity to numerous unremediated abandoned uranium mines. Metals including arsenic and uranium co-occur in and around these sites at levels higher than the United States Environmental Protection Agency maximum contaminant levels. To address the potential effect of these metals on the activation of CD4+ T-cells, we used RNA sequencing methods to determine the effect of exposure to uranyl acetate, sodium arsenite or a mixture of uranyl acetate and sodium arsenite. Oxidative stress is a mechanism proposed for metal toxicity, but findings for uranium differ across cell models. No significant changes in oxidative stress genes were detected for uranyl acetate, in contrast to sodium arsenite. Sodium arsenite induced a dose dependent effect on activation associated gene expression, targeting immune response genes at the lower dose. While uranyl acetate alone did not significantly alter activation associated gene expression, the mixture demonstrated a combined effect relative to sodium arsenite alone. The results demonstrate the need to investigate uranium alone and in metalloid mixtures at environmentally relevant concentrations to better understand the toxicological impact of these mixtures on T-cell activation, function and immune dysregulation.
Soil extracellular enzyme activities in plots dominated by trees that associate with arbuscular mycorrhizal or ectomycorrhizal fungi in the N fertilized and reference watershed at the Bear Brook Watershed in Maine, USA.
Our objective was to detect possible differences in N fertilization responses of soil extracellular enzymes in plots dominated by trees that associate with arbuscular mycorrhizal fungi (AM) or ectomycorrhizal fungi (ECM). To do this, we established a plot network of 6 AM and 6 ECM dominated (>65% diameter at breast height) 10 x 10 m plots in the lower elevation hardwood zone of both the reference and N fertilized watersheds (N=24 plots) at Bear Brook Watershed, in Maine USA. We assayed the potential activity of hydrolytic enzymes that release N (N-acetylglucosaminidase; NAG), phosphorus (acid phosphatase; AP), and simple carbon (ß-glucosidase; BG). In addition, we measured microbial allocation to complex C degrading oxidative enzymes phenol oxidase and peroxidase. The activities of these enzymes were measured separately in bulk mineral, rhizosphere, and organic horizon soils during the growing season in 2016.
Inorganic nitrogen, microbial ecoenzymatic activities, and organic matter in soils collected from the Monsoon Rainfall Manipulation Experiment (MRME), Sevilleta National Wildlife Refuge, New Mexico during the 2014 growing season
Drylands are characterized by a pulse dynamics framework in which episodic rain events trigger brief pulses of biological activity and resource availability that regulate primary production in these ecosystems. Relatively small rain events can stimulate microbial processes like decomposition that release inorganic nitrogen needed by plant processes, which typically also depend on soil moisture received from larger rain events. Little is known how changes in rainfall patterns may affect plant available nitrogen in dryland soils, particularly across temporal scales. Therefore, we conducted a study to examine the daily and seasonal responses of plant available nitrogen to rain events that differed in size and frequency throughout a summer monsoon in a northern Chihuahuan Desert grassland located in the Sevilleta National Wildlife Refuge, New Mexico, USA. This data package, which accompanies an associated manuscript (Brown et al. 2022), contains measurements of inorganic nitrogen, nitrogen-acquiring microbial ecoenzymatic activities, and organic matter in soils collected from the Monsoon Rainfall Manipulation Experiment (MRME) during the 2014 summer growing season.
Soil fungal community and activity under dominant plant species at the Sevilleta National Wildlife Refuge, New Mexico: October 2013
We measured fungal composition and activity in the soil under dominant plant species across a grassland to shrubland transition to determine if shrubs cultivate soil microbial communities as they encroach grasslands. The project was conducted in the northern Chihuahuan desert at the Sevilleta National Wildlife Refuge (site of the Sevilleta LTER) in New Mexico on October 20, 2013. Soils were collected under one shrub (Larrea tridentata) and three grass (Bouteloua eriopoda, Bouteloua gracilis, Pleuraphis jamesii) species in grassland, shrubland, and the ecotone region between grasslands and shrublands. Soil fungal communities were evaluated using DNA amplicon sequencing and fungal activity was quantified using several extracellular enzyme activity assays. Soil texture and soil chemistry were also measured.
Supplemental data Effects of imidacloprid exposure on honey bee colony growth and activity
To better understand how exposure to a low (5 ppb) concentration of imidacloprid affects honey bee colonies we conducted five field experiments involving a total of 54 bee colonies. In each experiment, bee colonies in one treatment group were fed sugar syrup adulterated with 5ppb imidacloprid over six weeks, and colonies in the other group were fed unadulturated sugar syrup over the same time period. Treatments were intended to simulate nectar collection by the colonies. No commercial agriculture existed within 10 km of the sites. We collected data from hive assessments, including adult bee mass and mass of food resources, and the total surface area of capped brood; and we collected data from sensors, including continuous hive weight, internal temperature and, for two years of the study, internal CO2 concentration. We measured Varroa mite fall before and after treatment each year of the study, and for 3 years of the study we measured the dry weight of newly-emerged adult bees.
Proteolytic enzyme activity of organic and mineral soil core samples collected near Toolik Lake field station, Alaska, July 2001
The original focus of this study was an analysis of proteolytic enzyme activity of Alaskan arctic tundra soils, however initial results raised questions regarding the method (Watanabe and Hayano, 1995). Thus, the goals of the study changed to 1) an investigation of the method, and 2) a comparison of enzyme activities of two different soil layers from the arctic tundra. Methodological examination included the impact of toluene, used to prevent immobilization of the product, and blank correction of enzyme activity, and a search for a true 6-h linear rate of activity during a 48-hour incubation. We measured native and potential, using casein as an artificial substrate, activities as net amino acid production in mineral and organic soil layer samples. Varying toluene concentration had no clear effect on activity; omitting toluene resulted in zero native activity and reduced potential for the organic samples, but not for the mineral. Comparison of activities with and without blank correction indicated, particularly for potential activity of samples with low native rates, that correction was required for accuracy. Native and potential activity of the organic samples, and native of the mineral were linear for the first 6 h of incubation; linearity was observed during the 6 to 24 h incubation for potential activity of the mineral. Soil layer activity data indicated that native activity was higher in organic soils as compared with mineral. The organic layer potential activity was ten-fold greater than the native, suggesting substrate limitation; potential and native activities did not differ in the mineral layer, indicating substrate sufficiency. Casein addition changed the kinetic pattern for both layers from hyperbolic to sigmoidal for the mineral and linear for the organic, implying different enzyme pools or behavioral changes of existing pools. Native activity based on total soluble protein was higher for the mineral samples relative to the organic, reiterating substrate
Carbon/Nitrogen Status Including Protease Activities of Arctic Soils Associated with Shrubs of Varying Height around Toolik Field Station, Alaska 2009.
Organic and mineral soil cores were collected from 18 transects differentiated by shrub height into three replica groups: high (average 64 cm ± SE 1.01); medium (39 ± SE 1); and low (18 ± SE 0.4); and percent plant functional group cover. Replica sample cores were taken from each transect, and after homogenization and K2SO4 extraction, if required, samples were analyzed for % C (carbon) and N (nitrogen); non-purgeable organic C (NPOC); total N (TN); dissolved inorganic and organic N (DIN, DON); microbial biomass C (MB-C) and N (MB-N). As a measure of N status, protease activity (native and potential) was determined together with total free amino acids and total soluble protein. Bulk density and pH values were also measured. K2SO4 extracted samples from a three-month incubation were analyzed as above and net mineralization was assessed.
Seeing the light: metabolic activity of restored and unrestored streams in the Baltimore, MD region.
The continually increasing global population residing in urban landscapes impacts numerous ecosystem functions and services provided by urban streams. Urban stream restoration is often employed to offset these impacts and conserve or enhance the various functions and services these streams provide. Despite the assumption that ‘if you build it, [the function] will come’, current understanding of the effects of urban stream restoration on stream ecosystem functions are based on short term studies which may not capture variation in restoration effectiveness over time. We quantified the impact of stream restoration on nutrient and energy dynamics of urban streams by studying 10 urban stream reaches (five restored, five unrestored) in the Baltimore, Maryland, USA, region over a two-year period. We measured gross primary production (GPP) and ecosystem respiration (ER) at the whole-stream scale continuously throughout the study and nitrate (NO3-N) spiraling rates seasonally (spring, summer, autumn) across all reaches. There was no significant restoration effect on NO3-N spiraling across reaches. However, there was a significant canopy cover effect on NO3-N spiraling, and directly comparing paired sets of unrestored-restored reaches showed that restoration does affect NO3-N spiraling after accounting for other environmental variation. Furthermore, there was a change in GPP:ER seasonality, with restored and open-canopied reaches exhibiting higher GPP:ER during summer. The restoration effect, though, appears contingent upon altered canopy cover, which is likely to be a temporary effect of restoration and is a driver of multiple ecosystem services, e.g., habitat, riparian nutrient processing. Our results suggest that decision-making about stream restoration, including evaluations of nutrient benefits, clearly needs to consider spatial and temporal dynamics of canopy cover and tradeoffs among multiple ecosystem services. Here we provide model estimates for GPP, ER, and net ecos
Seeing the light: high temporal frequency (5-10min resolution) measurements of dissolved oxygen, photosynthetically active radiation, temperature, and depth used to estimate metabolism in restored and unrestored Baltimore streams.
The continually increasing global population residing in urban landscapes impacts numerous ecosystem functions and services provided by urban streams. Urban stream restoration is often employed to offset these impacts and conserve or enhance the various functions and services these streams provide. Despite the assumption that ‘if you build it, [the function] will come’, current understanding of the effects of urban stream restoration on stream ecosystem functions are based on short term studies which may not capture variation in restoration effectiveness over time. We quantified the impact of stream restoration on nutrient and energy dynamics of urban streams by studying 10 urban stream reaches (five restored, five unrestored) in the Baltimore, Maryland, USA, region over a two-year period. We measured gross primary production (GPP) and ecosystem respiration (ER) at the whole-stream scale continuously throughout the study and nitrate (NO3-N) spiraling rates seasonally (spring, summer, autumn) across all reaches. There was no significant restoration effect on NO3-N spiraling across reaches. However, there was a significant canopy cover effect on NO3-N spiraling, and directly comparing paired sets of unrestored-restored reaches showed that restoration does affect NO3-N spiraling after accounting for other environmental variation. Furthermore, there was a change in GPP:ER seasonality, with restored and open-canopied reaches exhibiting higher GPP:ER during summer. The restoration effect, though, appears contingent upon altered canopy cover, which is likely to be a temporary effect of restoration and is a driver of multiple ecosystem services, e.g., habitat, riparian nutrient processing. Our results suggest that decision-making about stream restoration, including evaluations of nutrient benefits, clearly needs to consider spatial and temporal dynamics of canopy cover and tradeoffs among multiple ecosystem services. Here we provide the raw dissolved oxygen, temperature, li
Active layer depths: 150 mature black spruce sites in interior Alaska (2000-2003)
Maximum active layer depths at 150 extensive black spruce sites in interior Alaska collected in the summers of 2000, 2001, 2002 across the interior of Alaska along the Taylor highway, Alaska highway, Parks highway, Elliot highway, Steese highway, and Dalton highway.
Photosynthetically active radiation (PAR) data from APEX Fen, 2005 - 2006
Photosynthetically active radiation (PAR) data from the all plots of a soil climate manipulation experiment in an Alaskan rich fen (APEX). APEX Fen is located in the Bonanza Creek LTER outside of Fairbanks, AK. APEX Fen uses a full-factorial water table (flooded or raised, lowered or drained, and control treatments, as well as a moisture gradient) by warming manipulation (warmed, unwarmed treatment). We predicted that successional changes in vegetation due to our experiment would change incident PAR levels at the soil surface.
Eight Mile Lake Research Watershed, Thaw Gradient: Active Layer thickness 2004-2013.
In this larger study, we are asking the question: Is old carbon that comprises the bulk of the soil organic matter pool released in response to thawing of permafrost? We are answering this question by using a combination of field and laboratory experiments to measure net carbon exchange, radiocarbon isotope ratios in soil organic matter, soil respiration, and dissolved organic carbon, in tundra ecosystems. The objective of these proposed measurements is to develop a mechanistic understanding of the SOM sources contributing to C losses following permafrost thawing. We are making these measurements at an established tundra field site near Healy, Alaska in the foothills of the Alaska Range. Field measurements center on a natural experiment where permafrost has been observed to warm and thaw over the past several decades. This area represents a gradient of sites, each with a different degree of change due to permafrost thawing. In this area, we eatablished three sites with different degrees of disturbance from the permafrost thaw: 1) a relatively undisturbed tussock tundra (Minimal Thaw site), 2) a site adjacent to to the borehole which is monitoring permafrost thaw since 1985 with intermediate degree of disturbance (Moderate thaw site) and 3) a site where permafrost thaw apeared to have started more than three decades ago (Extensive thaw site) As such, this area is unique for addressing questions at the time and spatial scales relevant for change in arctic ecosystems. This data set includes the active layer depth (ALD), which is the maximum seasonal thaw depth from each of the three sites mentioned before.
Effect of insecticide treatment on Salix interior stem tannin activity and elemental composition.
This dataset contains information on stem chemistry of Salix interior within experimental plots on the Tanana River. There are 6 permanent plots, each of which contains two fenced subplots and two unfenced subplots. Subplots are sprayed with either insecticide (insect-treated subplots) or water (controls) annually. This particular dataset contains chemistry data for leaves collected from insecticide-treated and control subplots only within fenced subplots. The intent was to measure the effect of insect herbivory on chemistry in the absence of browsing.
Gap PAR (Photosynthetic Active Radiation) at the Coweeta Hydrologic Laboratory from 1993 to 1997
Small canopy openings often alter understory microclimate, leading to changes in forest structure and composition. It is generally accepted that physical changes in the understory (i.e., microclimatic) due to canopy removal drive changes in basic forest processes, particularly seedling recruitment which is intrinsically linked to soil moisture availability, light and, to a lesser extent, temperature. We examined the impact of small canopy gaps of the type (snags) and size (~300 m2) most frequently observed in the southern Appalachians on the understory microclimate. We created artificial canopy gaps at two elevations (a.m.s.l.) by girdling trees in areas with and without a Rhododendron maximum L. (rosebay rhododendron) understory. Soil and air temperature (degrees C), photosynthetically active radiation (PAR; mmol m-2s-1), and volumetric soil water content (WC%) in the upper 15 cm of soil were measured along transects generally running north to south through each gap.
Soil microbial activity and abundance data in the rhizosphere and bulk soils of O horizon in the MELNHE study, 2014
The Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE) project studies N and P acquisition and limitation through a series of nutrient manipulations in northern hardwood forests. This data set includes rhizosphere processes and microbial abundance at the Bartlett Experimental Forest. Samples were collected once, in summer 2014, in the forth year of fertilization with N and P. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Soil enzyme activity in the MELNHE study at Hubbard Brook Experimental Forest, Bartlett Experimental Forest, and Jeffers Brook, NH, 2014 and 2017
The Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE) project studies N and P acquisition and limitation through a series of nutrient manipulations in northern hardwood forests. This data set includes soil enzyme activities measured in Oe, Oa, and mineral soil horizons in all 13 of the MELNHE study sites (Bartlett EF, Hubbard EF, and Jeffers Brook, NH). Samples were collected in 2014 and 2017, representing 6 years of N and P fertilization. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.
Depth patterns of gross nitrogen cycling and soil exoenzyme activities for three northern hardwood forests
Despite the enormous size of the organic nitrogen (N) pool contained in mineral subsoils, rates of N cycling and soil exoenzyme activities are rarely measured in soils below 10 or 20 cm depth. Furthermore, assumed relationships between N mineralization rates and the activities of various decomposition exoenzymes are poorly characterized. We measured rates of gross and net N mineralization and nitrification as well as the potential activities of hydrolytic and oxidative enzymes at five soil depths (forest floor to 50 cm) in Spodosols at three hardwood forests of varying age (45 and 100 years post-harvest and old growth) at and near the Hubbard Brook Experimental Forest in New Hampshire, USA. As expected, rates of N cycling and potential enzyme activities per unit soil mass correlated strongly with soil carbon (C) concentration, and these parameters declined exponentially with increasing soil depth. After normalization per unit soil organic matter, N cycling rates and specific enzyme activities generally decreased little with depth within the mineral soil. Gross N mineralization rates correlated with specific activities of those enzymes that hydrolyze cellulose (β-glucosidase, cellobiohydrolase) and N-rich glucosamine polymers (N-acetylglucosaminidase), but not those that degrade protein or more complex C compounds. Hence, gross N cycling appear associated with the N released during microbial N recycling, rather than from decomposition of soil organic matter. Across the three stands, the youngest had a larger ratio of N- to-phosphorus-acquiring enzyme activities, indicating a greater N demand in younger than older forests. For all three stands, mineral soil below 10 cm contributed 30–53% of total gross and net N cycling per unit area to 50 cm depth. Overall, even though microbial N cycling and enzyme activities per unit soil mass decreased with depth, microbial processes in subsoils contributed substantially to ecosystem-scale gross N fluxes because of the sustained m
McMurdo Dry Valleys Lake Bonney Autonomous Lake Profiler and Samplers (ALPS): Photosynthetically Active Radiation
Knowledge of the McMurdo Dry Valley (MDV) lakes is limited by winter access, a period which is most relevant in understanding the habitability of other icy worlds and critical to understanding the overall function of these lakes. Owing to the lack of winter access, data that normally require human presence are incomplete. Our goal was to conduct the first year-round investigation of the biogeophysics of these unique lakes. An important part of the McMurdo Long Term Ecological Research (LTER) is evaluating carbon and nitrogen budgets in perennial ice-covered lakes. This data set addresses this core area of research and quantifies the intensity of photosynthetically active radiation (PAR) at specific depths in McMurdo Dry Valley lakes.
McMurdo Dry Valleys Community Respiration Rates : Quantifying the Activity of the Electron Transport System (ETS)
An important part of the McMurdo Long Term Ecological Research (LTER) is monitoring of spatial and temporal patterns, and processes that control net primary production (carbon dynamics) in perennial ice-covered lakes. One of the primary losses of carbon fixed by phytoplankton is through respiration, directly by the phytoplankton themselves and secondarily through the metabolic contributions of heterotrophic organisms such as bacterioplankton and protozoa. The coupling of low metabolic activity and supersaturated gases in the water column prohibits a direct measurement of respiration. Therefore, we measure the respiratory electron transport system (ETS) activity which drives oxidative phosphorylation, and hence oxygen consumption in all aerobic organisms (Packard 1985). This data set addresses this core area of research and estimates a community-wide respiration rate at specific depths in McMurdo Dry Valley lakes (Hoare, Fryxell and Bonney).
The Effect of Kangaroo-Rat Activity on Plant Species Composition at the Sevilleta National Wildlife Refuge, New Mexico (1999)
Our objective was to evaluate the effects of kangaroo rat mounds on species diversity and composition at a semiarid-arid grassland ecotone. We expected that source populations of plants occurring on kangaroo rat mounds have important influences on the species composition of vegetation at the landscape scale, and that these influences differ by grassland type. Our study was conducted at the Sevilleta LTER in New Mexico, where a grassland type dominated by Bouteloua gracilis, a shortgrass steppe species, and a grassland type dominated by B. eriopoda, a desert grassland species, meet to form patches across the landscape. Four 0.4 ha plots were sampled for species diversity and composition in a regular 7m x 7m grid in each grassland type. Kangaroo rat mounds were also mapped and sampled for vegetation measures in four areas of 1.6 ha in each type. The landscape scale abundance of many subordinate species was increased significantly by populations occurring on kangaroo rat mounds in both grassland types. However, the area affected by the burrowing activity of kangaroo rats was twice as large in the B. eriopoda dominated grassland type. Furthermore, dominant plants on mounds in the B. eriopoda type were also abundant in off-mound areas whereas dominant plants on mounds in the B. gracilis type were not as abundant off-mound. These results indicate that the presence of mounds in the B. gracilis dominated type is creating islands of plant communities that are distinct from the rest of the grassland. Therefore, the occurrence of certain plant species in this grassland type may be intimately associated with the disturbance regime at this ecotone. This study demonstrates that effects of small burrowing animals may facilitate the coexistence of species at this ecotone.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.