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.
49
datasets available to search
ShareScore release 0.7.1
Dataset results
49 results for “contrast variation”
Measuring the counterion cloud of soft microgels using SANS with contrast variation
<p>The behavior of microgels and other soft and compressible colloidal particles depends on particle concentration in ways that are absent in their hard-particulate counterparts. For instance, poly-N-isopropylacrylamide (pNIPAM) microgels can spontanously deswell and reduce suspension polydispersity at high concentrations. Despite the pNIPAM network in these microgels is uncharged, the key to understand this distinct behavior relies on the existence of peripheric charged groups, which provide stability when deswollen, and the associated counterion cloud. When in close proximity, clouds of different particles overlap, effectively freeing the associated counterions, which are then able to exert an osmotic pressure that can potentially cause the microgels to change size. Up to to now, however, no direct measurement of such an ionic cloud exists, perhaps even for hard colloids, where it is referred to as electric double layer. Here, we use small-angle neutron scattering with contrast variation with different ions to isolate the change in the form factor directly related to the counterion cloud and obtain its radius and width. Our results highlight that modeling of microgel suspensions must unavoidably and explicitly consider the presence of this cloud, which is present for nearly all microgel particles synthesized today.</p>
Retrotransposon-based genetic variation of Poa annua populations from contrasting climate conditions
<p>Raw photographs of agarose electrophoresis. Material: six Poa annua populations. Method: inter-Primer Binding Site (iPBS) markers This is the documentation of studies described in the manuscript entitled "Retrotransposon-based genetic variation of Poa annua populations from contrasting climate conditions" accepted for publication in PeerJ journal (decision received on 02.04.2019)</p>
Contrasting phylogeographic patterns of mitochondrial and genome-wide variation in the groundwater amphipod (Crangonyx islandicus) that survived the Ice age in Iceland
<p>In this zip "DataAvailability.zip" all the data and parameter files, as well as R scripts and bash codes used to perform the analyses of the mitochondrial and the RADseq data are provided. A ReadMe file is available at the root describing the content of the different folders and files.</p> <p>Below is the abstract of the associated manuscript:</p> <p>Analysis of phylogeographic patterns have often been based on mitochondrial DNA variation, but recent analyses dealing with nuclear DNA have in some instances revealed mito-nuclear discordances and complex evolutionary histories. These enigmatic scenarios which may involve stochastic lineage sorting, ancestral hybridization, past dispersal, and secondary contacts are increasingly scrutinized with a new generation of genomic tools such as RADseq, which pose also additional analytical challenges. Here, we revisited the previously inconclusive phylogeographic history, showing mito-nuclear discordance, of an endemic groundwater amphipod from Iceland, <em>Crangonyx islandicus,</em> which is the only metazoan known to have survived the Pleistocene beneath the glaciers. Previous studies based on three DNA markers documented a mitochondrial scenario with the main divergence occurring between populations in northern Iceland and an ITS scenario with the main divergence between the south and north. We used double digest restriction-site-associated DNA sequencing (ddRADseq) to clarify this mito-nuclear discordance by applying several statistical methods while estimating the sensitivity to different analytical approaches (data-type, differentiation indices and base call uncertainty). A majority of nuclear markers and methods support the ITS divergence. Nevertheless, a more complex scenario emerges, possibly involving introgression led by male-biased dispersal among northern locations or mitochondrial capture which may have been further strengthened by natural selection.</p>
Data from: Microgeographic variation in early fitness traits of Pinus sylvestris from contrasting soils
<p>Seedling phenotypic data from two Iberian <em>Pinus sylvestris</em><em> </em>provenances from contrasting soils (calcareous vs. siliceous) grown in a 3-year greenhouse experiment on both types of natural local substrate. Each line in the file corresponds to a different seedling. Phenotypic variables as described in the original paper published in American Journal of Botany, doi <a href="https://doi.org/10.1002/ajb2.16159">10.1002/ajb2.16159</a></p>
Genotype and genetic diversity data for: Contrasts in riverscape patterns of intraspecific genetic variation in a diverse Neotropical fish community of high conservation value
<p><span>Spatial patterns in genetic variation compared across species provide information about the predictability of genetic diversity of natural populations and areas requiring conservation measures. Due to their remarkable fish diversity, rivers in Neotropical regions are ideal systems to confront theory with observations and would benefit greatly from such approaches given their increasing vulnerability to anthropogenic pressures. We used SNP data from 18 fish species with contrasting life-history traits, co-sampled across 12 sites in the Maroni – a major river system from the Guiana Shield – to compare patterns of intraspecific genetic variation and identify their underlying drivers. Analyses of covariance revealed a decrease in genetic diversity as distance from the river outlet increased for 5 of the 18 species, illustrating a pattern commonly observed in riverscapes for species with low-to-medium dispersal abilities. However, mean within-site genetic diversity was lowest in the two easternmost tributaries of the Upper Maroni and around an urbanized location downstream, indicating the need to address the potential influence of local pressures in these areas, such as goldmining or fishing. Finally, the relative influence of isolation by stream distance, isolation by discontinuous river flow and isolation by spatial heterogeneity in effective size on pairwise genetic differentiation varied across species. Species with similar dispersal and reproductive guilds did not necessarily display shared patterns of population structure. Increasing the knowledge of specific life history traits and ecological requirements of fish species in these remote areas should help further understand factors that influence their current patterns of genetic variation.</span></p>
Data from: The duration of high spring light for understory plants: contrasting responses to spatial and temporal temperature variation
Open the record for dataset details and reuse information.
Genotype and genetic diversity data for: Contrasts in riverscape patterns of intraspecific genetic variation in a diverse Neotropical fish community of high conservation value
Open the record for dataset details and reuse information.
Data from: Contrasting patterns of leaf trait variation among and within species during tropical dry forest succession in Costa Rica
A coordinated response to environmental drivers amongst individual functional traits is central to the plant strategy concept. However, whether the trait co-ordination observed at the global scale occurs at other ecological scales (especially within species) remains an open question. Here, for sapling communities of two tropical dry forest types in Costa Rica, we show large differences amongst traits in the relative contribution of species turnover and intraspecific variation to their directional changes in response to environmental changes along a successional gradient. We studied the response of functional traits associated with the leaf economics spectrum and drought tolerance using intensive sampling to analyse inter- and intra-specific responses to environmental changes and ontogeny. Although the overall functional composition of the sapling communities changed during succession more through species turnover than through intraspecific trait variation, their relative contributions differed greatly amongst traits. For instance, community mean specific leaf area changed mostly due to intraspecific variation. Traits of the leaf economics spectrum showed decoupled responses to environmental drivers and ontogeny. These findings emphasise how divergent ecological mechanisms combine to cause great differences in changes of individual functional traits over environmental gradients and ecological scales.
Data for 'Phenotypic plasticity and genetic variation in leaf traits of Yushania niitakayamensis (Bambusoideae; Poaceae) in contrasting light environments'
<p>This is the Data for the article entitled 'Phenotypic plasticity and genetic variation in leaf traits of Yushania niitakayamensis (Bambusoideae; Poaceae) in contrasting light environments' submitted to 'Journal of Plant Research'</p> <p><a href="https://doi.org/10.1007/s10265-021-01327-y">https://doi.org/10.1007/s10265-021-01327-y</a></p> <p>Traits' names are listed below:</p> <p>Leaf length (LL), Leaf width (LW), Specific leaf area (SLA), Stomatal density (SD), Leaf thickness (LT), Relative frequency of cavities formed by the collapsed fusoid cells (CFC), Leaf chlorophyll content per unit area ([Chl]area), Ratio of chlorophyll a to chlorophyll b (Chl a/b), Leaf nitrogen content per unit area ([N]area), Leaf stable carbon isotope ratio (δ13C), Photosynthetic photon flux density (PPFD), Actual quantum yield of PSII electron transport (ΦPSII), Electron transport rate (ETR), Light-saturated photosynthetic rate (Asat), Stomatal conductance (gs), Dark respiration rate (Rd), Apparent quantum yield (AQY), The ratio of intercellular to ambient CO2 concentration (Ci/Ca), Photosynthetic water use efficiency (WUE)</p>
Data from: Continuous variation in an aposematic pattern affects background contrast, but is not associated with differences in microhabitat use
<p>Variation in aposematic signals was once predicted to be rare, yet in recent years it has become increasingly well-documented. Despite increases in the frequency with which polytypism and polymorphism have been suggested to occur, population-wide variance is rarely quantified. We comprehensively sampled a subpopulation of the poison frog <em>Oophaga sylvatica</em>, a species which is polytypic across its distribution and also shows considerable within-population polymorphism. On one hand, color pattern polymorphism could be the result of multifarious selection acting to balance different signaling functions and leading to the evolution of discrete sub-morphs which occupy different fitness peaks. Alternatively, variance could simply be due to relaxed selection, where variation would be predicted to be continuous. We used visual modeling of conspecific and heterospecific observers to quantify the extent of within-population phenotypic variation and assess whether this variation produced distinct signals. We found that, despite considerable color pattern variation, variance could not be partitioned into distinct groups, but rather all viewers would be likely to perceive variation as continuous. Similarly, we found no evidence that frog color pattern contrast was either enhanced or diminished in the frogs' chosen microhabitats compared to alternative patches in which conspecifics were observed. Within population phenotypic variance therefore does not seem to be indicative of strong selection towards multiple signaling strategies, but rather pattern divergence has likely arisen due to weak purifying selection, or neutral processes, on a signal that is highly salient to both conspecifics and predators.</p>
Contrasting patterns of sequence variation in steelhead populations reflect distinct evolutionary processes
<p>Multiple evolutionary processes influence genome‐wide allele frequencies and quantifying effects of genetic drift, and multiple forms of selection remain challenging in natural populations. Here, we investigate variation at major effect loci in contrast to patterns of neutral drift across a wide collection of steelhead (<em>Oncorhynchus mykiss</em>) populations that have declined in abundance due to anthropogenic impacts. Whole‐genome resequencing of 74 populations of steelhead revealed genome‐wide patterns (~8 million SNPs) consistent with expected neutral population structure. However, allelic variation at major effect loci associated with adult migration timing (chromosome 28: GREB1L/ROCK1) and age at maturity (chromosome 25: SIX6) reflected how selection has acted on phenotypic variation in contrast with neutral structure. Variation at major effect loci was influenced by evolutionary processes with differing signals between the strongly divergent Coastal and Inland lineages, while allele frequencies within and among populations within the Inland lineage have been driven by local natural selection as well as recent anthropogenic influences. Recent anthropogenic effects appeared to have influenced the frequency of major effect alleles including artificial selection for specific traits in hatchery stocks with subsequent gene flow into natural populations. Selection from environmental factors at various scales has also likely influenced variation for major effect alleles. These results reveal evolutionary mechanisms that influence allele frequencies at major effect loci that are critical for conservation of phenotypic traits and life history variation of this protected species.</p>
Dataset: Periodic variation of mesoscale ultraviolet contrast at the cloud top of Venus
<p>Filename:<br> mean_A_283.txt : wavelength of 283 nm<br> mean_A_365.txt : wavelengths of 365 nm</p> <p>Description:<br> Empirical equigonal UV albedo of Venus as a function of the phase angle determined from Akatsuki UVI data.</p> <p>Format (text file): <br> 1st column: Phase angle (deg)<br> 2nd column: A:Mean albedo<br> 3rd column: SD:Standard deviation</p> <p> </p> <p>Filename:<br> period1_283nm.txt : Period 1, 283 nm<br> period1_365nm.txt : Period 1, 365 nm<br> period2_283nm.txt : Period 2, 283 nm<br> period2_365nm.txt : Period 2, 365 nm</p> <p>Description:<br> Time series of the standard deviation of mesoscale UV contrast and the mean brightness of Venus.</p> <p>Format (text file):<br> 1st column: Image file name<br> 2nd column: Elapsed time (h)<br> 3rd column: Phase angle (deg)<br> 4th column: Standard deviation (W/m2/str/m)<br> 5th column: Standard deviation in AM<br> 6th column: Standard deviation in PM<br> 7th column: Mean brightness (W/m2/str/m)<br> 8th column: Mean brightness in AM<br> 9th column: Mean brightness in PM</p> <p> </p> <p>Filename:<br> uvi_20160425_131340_283_l3b_v10.nc<br> uvi_20160425_151341_283_l3b_v10.nc<br> uvi_20160425_171339_283_l3b_v10.nc<br> uvi_20160506_101341_283_l3b_v10.nc<br> uvi_20160506_121340_283_l3b_v10.nc<br> uvi_20160506_141343_283_l3b_v10.nc<br> uvi_20160517_141339_283_l3b_v10.nc<br> uvi_20160517_161339_283_l3b_v10.nc</p> <p>Description:<br> 2.02-micrometer mapped data taken by the IR2 camera onboard Akatsuki in Level-3 netCDF format. The data have been corrected for the point-spread function, the flat-field pattern, and the detector temperature dependence by Sato et al. (2020, Icarus, 345, 113682, https://doi.org/10.1016/j.icarus.2020.113682).</p> <p>Format (binary file):<br> netCDF<br> The file names indicate the year, date and time of each observation.</p> <p> </p>
Data from: Contrasting patterns of leaf trait variation among and within species during tropical dry forest succession in Costa Rica
Open the record for dataset details and reuse information.
Data from: Continuous variation in an aposematic pattern affects background contrast, but is not associated with differences in microhabitat use
Open the record for dataset details and reuse information.
Data from: Genetic variation and structure in contrasting geographic distributions: widespread vs. restricted black-tailed prairie dogs (subgenus Cynomys)
Open the record for dataset details and reuse information.
Contrasting patterns of sequence variation in steelhead populations reflect distinct evolutionary processes
Open the record for dataset details and reuse information.
Data from: Comparative multi-locus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation
While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species-specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree-killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles' entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long-standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced.
Data from: Molecular phylogeny of Terniopsis (Podostemaceae) and contrasting molecular and morphological variations in two species
Podostemaceae show different patterns of morphological variation relative to molecular ones between genera and between species, but additional material was necessary to make the patterns clearer. Using new material collected from Cambodia, we compared the variations of Terniopsis chanthaburiensis and T. heterostaminata in Cambodia, Laos and Thailand, and conducted matK phylogenetic analysis with many samples and most species of the genus. In contrast to the narrow molecular variation, the morphological variation (e.g., in the length of the shoots and pedicels) is large and continuous. The results indicate that variation in the two species is intraspecific. A similar pattern exists in two pairs of other species of Terniopsis, in which the morphological variation is large and discontinuous, while there is little molecular difference. The opposite pattern is present in other cases (e.g., Dalzellia zeylanica and Tristicha trifaria). The variation in T. chanthaburiensis and T. heterostaminata does not appear to be a response to variation in the habitats, that is submerged rock surfaces in fast currents. Distributional and phylogenetic data indicate that Terniopsis diversified primarily in Laos and Thailand, then expanded into neighboring regions. A synopsis of the genus Terniopsis and its 14 species is given.
Data from: Individual variation in cone photoreceptor density in house sparrows: implications for between-individual differences in visual resolution and chromatic contrast
Between-individual variation has been documented in a wide variety of taxa, especially for behavioral characteristics; however, intra-population variation in sensory systems has not received similar attention in wild animals. We measured a key trait of the visual system, the density of retinal cone photoreceptors, in a wild population of house sparrows (Passer domesticus). We tested whether individuals differed from each other in cone densities given within-individual variation across the retina and across eyes. We further tested whether the existing variation could lead to individual differences in two aspects of perception: visual resolution and chromatic contrast. We found consistent between-individual variation in the densities of all five types of avian cones, involved in chromatic and achromatic vision. Using perceptual modeling, we found that this degree of variation translated into significant between-individual differences in visual resolution and the chromatic contrast of a plumage signal that has been associated with mate choice and agonistic interactions. However, there was no evidence for a relationship between individual visual resolution and chromatic contrast. The implication is that some birds may have the sensory potential to perform "better" in certain visual tasks, but not necessarily in both resolution and contrast simultaneously. Overall, our findings (a) highlight the need to consider multiple individuals when characterizing sensory traits of a species, and (b) provide some mechanistic basis for between-individual variation in different behaviors (i.e., animal personalities) and for testing the predictions of several widely accepted hypotheses (e.g., honest signaling).
Data from: Spatio-temporal variation in fitness responses to contrasting environments in Arabidopsis thaliana
The evolutionary response of organisms to global climate change is expected to be strongly conditioned by pre-existing standing genetic variation. In addition, natural selection imposed by global climate change on fitness-related traits can be heterogeneous over time. We estimated selection of life-history traits of an entire genetic lineage of the plant A. thaliana occurring in north-western Iberian Peninsula that were transplanted over multiple years into two environmentally contrasting field sites in southern Spain, as southern environments are expected to move progressively northwards with climate change in the Iberian Peninsula. The results indicated that natural selection on flowering time prevailed over that on recruitment. Selection favored early flowering in six of eight experiments and late flowering in the other two. Such heterogeneity of selection for flowering time might be a powerful mechanism for maintaining genetic diversity in the long run. We also found that north-western A. thaliana accessions from warmer environments exhibited higher fitness and higher phenotypic plasticity for flowering time in southern experimental facilities. Overall, our transplant experiments suggested that north-western Iberian A. thaliana has the means to cope with increasingly warmer environments in the region as predicted by trends in global climate change models.
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.