Find research datasets worth reusing

Shared response to changes in drainage basin: Phylogeography of the Yunnan Small Narrow-mouthed Frog, Glyphoglossus yunnanensis (Anura: Microhylidae)

Aim: With the late Cenozoic uplift of the Qinghai-Tibetan Plateau (QTP), drainage of the southeastern edge of the QTP changed significantly. However, the impact of this dramatic change on the geographical distribution and genetic diversity of endemic organisms is still poorly understood. Here, we examined the geographical patterns of genetic variation in the Yunnan small narrow-mouthed frog, Glyphoglossus yunnanensis (Microhylidae), and two alternative hypotheses were tested: that is, the geographical distribution of genetic variation was determined by either the contemporary drainage basin or by historical drainage basins. Location: the Mountains of Southwest China. Materials and methods: Analyses were based on 417 specimens collected from across the distribution of the species. We reconstructed the genealogy (Bayesian and maximum parsimony methods) and assessed demographic history based on DNA sequencing data from mitochondrial and nuclear markers. We also mapped the genetic diversity and estimated the divergence times by a relaxed clock model. Results: The species has maintained a relatively stable population size without recent population expansion. Four major maternal lineages were identified with good support, one representing a possible cryptic species and the other three showing further subdivision. The distribution of these deeply differentiated lineages/sublineages corresponded well to geographical regions. The secondary contact zones and phylogeographic breaks in distinct lineages of G. yunnanensis were almost concordant with those of Nanorana yunnanensis. Main conclusions: Lineage division conformed to the hypothesis of drainage system evolution, that is, the phylogeographic pattern of G. yunnanensis was shaped by historical drainage patterns. Concordance in phylogeographic patterns may suggest a shared response to common hydrogeological history, and also might indicate that there was more contribution of the drainage history than ecological or life history traits in structuring genetic variation between these two disparate codistributed taxa G. yunnanensis and N. yunnanensis.

Responses of a resident group to an outsider in the blue-breasted quail: a paradigm for studying social resettlement of dispersers

Dispersal is an individual life history trait that can influence the ecological and evolutionary dynamics of both the source and recipient populations. Current studies of animal dispersal have paid little attention to how the responses of residents in a recipient population affect the social resettlement of dispersers into a new habitat. We addressed this question in the blue-breasted quail Synoicus chinensis by designing an outsider introduction experiment to simulate a scenario of interaction between residents and dispersers. In the experiment, we introduced an unfamiliar quail into a group of three differently ranked residents and then examined their behavioral responses to the arrival of the outsider. We found that all residents made negative responses by pecking at the outsider to maintain their pecking order, in which high-ranked residents displayed significantly greater intensity than those of lower ranks. This result highlighted that adverse behavioral responses of residents would prevent outsiders from obtaining hierarchical dominance in the recipient group. Moreover, the residents' sex ratio, their relative ages to the outsiders, and whether outsiders counter-pecked at the residents all influenced the probability of outsiders prevailing against the residents. Those outsiders that displayed counter-peck courage were more likely to gain higher dominance and hence resettle into the recipient group successfully. Our findings suggest that resident groups may impose a selection among dispersers via adverse behavioral responses. Therefore, social factors that can influence the resettlement step of dispersers in a new habitat should be accounted for in future studies of animal dispersal.

Data from: Bighorn sheep show similar in-host responses to the same pathogen strain in two contrasting environments

Ecological context – the biotic and abiotic environment, along with its influence on population mixing dynamics and individual susceptibility – are thought to have major bearing on epidemic outcomes. However, direct comparisons of disease events in contrasting ecological contexts in wildlife systems are often confounded by concurrent differences in host genetics, exposure histories, or pathogen strains. Here, we compare disease dynamics of a Mycoplasma ovipneumoniae spillover event that affected bighorn sheep populations in two contrasting ecological contexts. One event occurred on the herd's home range near the Rio Grande Gorge in New Mexico, while the other occurred in a captive facility at Hardware Ranch in Utah. While data collection regimens varied between the two sites, general patterns of antibody signal strength and symptom emergence were consistent. Symptoms appeared in the captive setting an average of 12.9 days post-exposure, average time to seroconversion was 24.9 days, and clinical signs peaked at approximately 36 days post-infection. These patterns were consistent with serological testing and subsequent declines in symptom intensity in the free-ranging herd. At the captive site, older animals exhibited more severe declines in body condition and loin thickness, higher symptom burdens, and slower antibody response to the pathogen than younger animals. Younger animals were more likely than older animals to clear infection by the time of sampling at both sites. The patterns presented here suggest that environment may not be a major determinant of epidemiological outcomes in the bighorn sheep - M. ovipneumoniae system, elevating the possibility that host- or pathogen-factors may be responsible for observed variation.

The metabolic hormone adiponectin affects the correlation between nutritional status and pneumococcal vaccine response in vulnerable indigenous children

Background: Almost 200 million children worldwide are either undernourished or overweight. Only a few studies have addressed the effect of variation in nutritional status on vaccine response. We previously demonstrated an association between stunting and an increased post-vaccination 13-valent pneumococcal conjugate vaccine (PCV13) response. In this prospective study, we assessed to what extent metabolic hormones may be a modifier in the association between nutritional status and PCV13 response. Methods: Venezuelan children aged 6 weeks to 59 months were vaccinated with a primary series of PCV13. Nutritional status and serum levels of leptin, adiponectin and ghrelin were measured upon vaccination and their combined effect on serum post-vaccination antibody concentrations was assessed by generalized estimating equations multivariable regression analysis. Results: A total of 210 children were included, of whom 80 were stunted, 81 had a normal weight and 49 were overweight. Overweight children had lower post-vaccination antibody concentrations than normal weight children (regression coefficient -1.15, 95% CI -2.22 – -0.072). Additionally, there was a significant adiponectin-nutritional status interaction. In stunted children, higher adiponectin serum concentrations were associated with lower post-PCV13 antibody concentrations (regression coefficient -0.19, 95% CI -0.24 – -0.14) while the opposite was seen in overweight children (regression coefficient 0.14, 95% CI 0.049 – 0.22). Conclusion: Metabolic hormones, in particular adiponectin, may modify the effect of nutritional status on pneumococcal vaccine response. These findings emphasize the importance of further research to better understand the immunometabolic pathways underlying vaccine response and enable a future of optimal personalized vaccination schedules.

opencc-by-4.0Jun 2022View details →

Transient Freeze-Thaw Responses to the 2018 and 2019 Fires near Batagaika Megaslump, Northeast Siberia

This repository contains the dataset for the Transient Freeze-Thaw Responses to the 2018 and 2019 Fires near Batagaika Megaslump, Northeast Siberia. All files are formatted as CSV.  TD_Burn14_site1.csv contains thaw depth data at the site1 in the 2014 fire scar.  TD_Burn14_site2.csv contains thaw depth data at the site2 in the 2014 fire scar. TD_Burn18.csv contains thaw depth data in the 2018 fire scar. TD_Unburn-Burn19.csv contains thaw depth data along the transect across the 2019 fire scar and unburned control site. TD_Unburn18.csv contains thaw depth data in the unburned control site for the 2018 fire scar. Temperature_TidbiT_190924-210916.csv contains hourly air and surface temperature data from 24 September 2019 to 16 September 2016. All data were taken by the TidbiT logger.

European badger (Meles meles) responses to low-intensity, selective culling: using mark recapture and relatedness data to assess social perturbation

Culling the main wildlife host of bovine tuberculosis in Great Britain (GB) and Ireland, the European badger (Meles meles) to reduce infections in cattle, has been employed in both territories. In GB, this has been controversial, with results suggesting that culling induces disturbance to badger social structure, facilitating wider disease dissemination. Previous analyses hypothesized that even very low-level, selective culling may cause similar deleterious effects by increasing ranging of individuals and greater mixing between social-groups. To assess this hypothesis, a novel, prospective, landscape-scale 'before-and-after' Test and vaccinate or remove (TVR) study was implemented. Test-positive badgers were culled and test-negative badgers were BCG vaccinated and released. Mark-recapture metrics of badger ranging and genetic metrics of social group relatedness did not change significantly over the study period. However, selective culling was associated with a localised reduction in social-group relatedness in culled groups. Synthesis and application: Ecological context is important; extrapolation across territories and other disease epidemiological-systems (epi-systems) is likely to be challenging. However, we demonstrate that small-scale, selective removal of test-positive badgers was not associated with metrics of increased ranging but was associated with localised changes in social-group relatedness. This adds to the evidence base on badger control options for policy makers.

Light condition experienced by parent plants influences the response of offspring to light via both parental effects and soil legacy effects

1. Environmental conditions experienced by parent plants can influence offspring performance through parental effects induced by DNA methylation. The offspring can also be influenced by environmental conditions experienced by their parents via soil legacy effects due to plant-mediated changes in the composition of soil microbes. These two effects are likely to act simultaneously, but empirical evidence for combined effects is limited. 2. We conducted a two-phase experiment with five genotypes of a clonal plant Hydrocotyle vulgaris. In the first phase, we grew parent plants of each genotype under two light conditions (ambient vs. shade) and two DNA demethylation treatments (treated with water vs. 5-azacytidine). We then collected soils and clonal offspring for each genotype from each of these four treatments and measured soil (a)biotic properties. In the second phase, we grew the offspring from each of the four treatments in the four different soils, under the two light conditions. 3. When grown under ambient light condition and in soil from ambient parents, offspring produced by ambient parents grew larger than offspring produced by shaded parents when the parents were treated with water. This difference was smaller when the parents were treated with 5-azacytidine, and disappeared when the offspring were grown in soil from shaded parents. The growth difference was also observed when the offspring were grown under shaded condition and in soil from shaded parents. However, this difference was greater when the parents were treated with 5-azacytidine, and disappeared when the offspring were grown in soil from ambient parents. Moreover, offspring growth was associated with fungal composition and total phosphorus of the soil in which the parents had grown. 4. Our results show, for the first time, that light condition experienced by parents can influence offspring responses to light through both parental effects and soil legacies. The parental effects were mediated by changes in DNA methylation and the soil legacies were due to plant-mediated changes in a combination of soil biotic and abiotic properties. These impacts may eventually influence the ecological and evolutionary trajectories of clonal plant populations.

opencc-by-4.0Mar 2022View details →

Research Data Supporting "Coupling Lipid Nanoparticle Structure and Automated Single Particle Composition Analysis to Design Phospholipase Responsive Nanocarriers"

Raw research data supporting Barriga, Pence, et al. 2022, Advanced Materials. <a href="https://doi.org/10.1002/adma.202200839">https://doi.org/10.1002/adma.202200839</a>

Data from: Widespread bird species show idiosyncratic responses in residual body mass to selective logging and edge effects in the Colombian Western Andes

This dataset consists of banding data (N = 1589 captures, 129 bird species), including morphological and breeding biology measures, collected from understory birds in subtropical cloudforest at roughly 2000 m.a.s.l. in the municipality of El Cairo in Colombia's Western Andes (Serrania de los Paraguas range). Roughly 8,350 net hours were divided into two three-month field seasons (June-August 2017 and January-March 2018), both corresponding to local dry seasons. Birds were banded along 500-meter transects in forest interior across a gradient of forest fragment patch sizes (N = 8 fragments, area range = 10-173 ha) and a private ~750 ha reserve (Reserva Natural Cerro El Ingles) in the same landscape. Each non-hummingbird capture was fitted with an aluminum leg band with a unique combination, and we collected data on mass, tarsus length, wing chord, pectoral muscle score, cloacal protuberance and brood patch score, and age and sex (where possible due to plumage differences). We captured 101 species (including 6 boreal migrants) in 844 captures (53%) during the January-March sampling period and 102 species in 745 captures during the June-August sampling period; each site was sampled during both sampling periods. The most captured bird families were Trochilidae (24 spp., 36% of total captures), Thraupidae (17 spp.), Tyrannidae (16 spp.), Furnariidae (14 spp.), and Turdidae (6 spp.). A subset of these data (uploaded as a separate file) were used to calculate body condition indices for 20 species of commonly captured birds (N = 984 captures) that occured across much of the patch size gradient (at least 8 out of 14 transects), and were related to fragment area and measures of edge and selective logging effects (see Jones et al. 2022). In this file, we include all predictor variables necessary to run the generalized linear mixed models in Jones et al. (2022), including proportion forest cover within 1 km (a proxy for patch size), edge density, average distance to forest edge from the netting transect, average canopy cover and height along the transect, multivariate measures of understory plant density, large-diameter tree density, and vertical vegetation structure, elevation of each transect, and average yearly rainfall for each transect.

Divergent trait responses to nitrogen addition in tall and short species

Asymmetrical light competition and direct detrimental effect of nitrogen have been proposed as two main mechanisms driving species richness declines following nitrogen (N) addition. N addition is also known to alter functional trait composition towards increased dominance of tall and fast-growing species. However, whether trait changes vary between species and, in particular, how the traits of tall and short species respond to N addition has rarely been studied. Understanding whether different trait changes occur for tall and short species would provide insight into mechanisms underlying N addition effects. Based on a long-term N addition experiment, we measured the natural height of 44 plant species and the photosynthetic active radiation (PAR) at seven heights in the vegetation and identified a clear stratification of the plant community into tall species (>30cm tall), which experienced high light conditions, and short species that grew under the canopy. We also measured four functional traits, including maximum plant height, specific leaf area, leaf dry matter content and leaf thickness, on 35 species that occurred in fertilized and unfertilized plots. Structural equation modelling revealed that nitrogen (N) addition significantly reduced species richness by enhancing light asymmetry and had no direct effects, suggesting that N detrimental effects are negligible in our system. Consistent with this, we found different responses of traits and diversity for the tall and short species. Specifically, N addition reduced the number of short species but increased the number of tall species. In addition, specific leaf area increased, and leaf dry matter content decreased, for short species only, suggesting that they shifted to a fast growth strategy to cope with lower light levels. In contrast, tall species increased their height further to capture more light at the top of the canopy. Synthesis. The divergent trait responses observed for tall and short species show that although certain traits, like height and leaf traits, show correlated responses at the whole community level, these correlations may not be consistent across all species. Together, our results highlight that light competition is the main mechanism driving species loss following N addition gradient.

The transcription factor network of E. coli steers global responses to shifts in RNAP concentration

The robustness and sensitivity of gene networks to environmental changes is critical for cell survival. How gene networks produce specific, chronologically ordered responses to genome-wide perturbations, while robustly maintaining homeostasis, remains an open question. We analysed if short- and mid-term genome-wide responses to shifts in RNA polymerase (RNAP) concentration are influenced by the known topology and logic of the transcription factor network (TFN) of Escherichia coli. We found that, at the gene cohort level, the magnitude of the single-gene, mid-term transcriptional responses to changes in RNAP concentration can be explained by the absolute difference between the gene's numbers of activating and repressing input transcription factors (TFs). Interestingly, this difference is strongly positively correlated with the number of input TFs of the gene. Meanwhile, short-term responses showed only weak influence from the TFN. Our results suggest that the global topological traits of the TFN of E. coli shape which gene cohorts respond to genome-wide stresses.

Response to immune checkpoint blockade improved in pre-clinical model of breast cancer after bariatric surgery

Bariatric surgery is becoming more prevalent as a sustainable weight loss approach, with vertical sleeve gastrectomy (VSG) being the first line of surgical intervention. We and others have shown that obesity exacerbates tumor growth while diet-induced weight loss impairs obesity-driven progression. It remains unknown how bariatric surgery-induced weight loss impacts cancer progression or alters responses to therapy. Using a pre-clinical model of diet induced obesity followed by VSG or diet-induced weight loss, breast cancer progression and immune checkpoint blockade therapy was investigated. Weight loss by bariatric surgery or weight matched dietary intervention before tumor engraftment protected against obesity-exacerbated tumor progression. However, VSG was not as effective as dietary intervention in reducing tumor burden despite achieving similar extent of weight and adiposity loss. Circulating leptin did not associate with changes in tumor burden. Uniquely, tumors in mice that received VSG displayed elevated inflammation and checkpoint ligand PD-L1. Further, mice that received VSG had reduced tumor infiltrating T lymphocytes suggesting an ineffective anti-tumor microenvironment. VSG-associated elevation of PD-L1 prompted us to next investigate the efficacy of immune checkpoint inhibitors in lean, obese, and formerly obese mice that lost weight by VSG or weight matched controls. While obese mice were resistant to immunotherapy, anti-PD-L1 potently impaired tumor progression after VSG through improved anti-tumor immunity. Thus, in formerly obese mice, surgical weight loss followed by immunotherapy reduced breast cancer burden. Further studies are necessary to determine how bariatric surgery sensitizes tumors to immune checkpoint inhibition.

opencc-zeroDec 2021View details →

Invasive rodent responses to experimental and natural hurricanes with implications for global climate change

Hurricanes cause dramatic changes to forests by opening the canopy and depositing debris onto the forest floor. How invasive rodent populations respond to hurricanes is not well understood, but shifts in rodent abundance and foraging may result from scarce fruit and seed resources that follow hurricanes. We conducted studies in a wet tropical forest in Puerto Rico to better understand how experimental (Canopy Trimming Experiment) and natural (Hurricane Maria) hurricane effects alter populations of invasive rodents (Rattus rattus [rats] and Mus musculus [mice]) and their foraging behaviors. To monitor rodent populations, we used tracking tunnels (inked and baited cards inside tunnels enabling identification of animal visitors' footprints) within experimental hurricane plots (arborist trimmed in 2014) and reference plots (closed canopy forest). To assess shifts in rodent foraging, we compared seed removal of two tree species (Guarea guidonia and Prestoea acuminata) between vertebrate-excluded and free-access treatments in the same experimental and reference plots, and did so 3 months before and 9 months after Hurricane Maria (2017). Trail cameras were used to identify animals responsible for seed removal. Rat incidences generated from tracking tunnel surveys indicated that rat populations were not significantly affected by experimental or natural hurricanes. Before Hurricane Maria there were no mice in the forest interior, yet mice were present in forest plots closest to the road after the hurricane, and their forest invasion coincided with increased grass cover resulting from open forest canopy. Seed removal of Guarea and Prestoea across all plots was rat dominated (75%-100% rat-removed) and was significantly less after than before Hurricane Maria. However, following Hurricane Maria, the experimental hurricane treatment plots of 2014 had 3.6 times greater seed removal by invasive rats than did the reference plots, which may have resulted from rats selecting post-hurricane forest patches with greater understory cover for foraging. Invasive rodents are resistant to hurricane disturbance in this forest. Predictions of increased hurricane frequency from expected climate change should result in forest with more frequent periods of grassy understories and mouse presence, as well as with heightened rat foraging for fruit and seed in pre-existing areas of disturbance.

Transcriptional response of mushrooms to artificial sun exposure

Climate change causes increased tree mortality leading to canopy loss and thus sun-exposed forest floors. Sun exposure creates extreme temperatures and radiation, with potentially more drastic effects on forest organisms than the current increase in mean temperature. Such conditions might potentially negatively affect the maturation of mushrooms of forest fungi. A failure of reaching maturation would mean no sexual spore release and, thus, entail a loss of genetic diversity. However, we currently have a limited understanding of the quality and quantity of mushroom-specific molecular responses caused by sun exposure. Thus, to understand the short-term responses towards enhanced sun exposure, we exposed mushrooms of the wood-inhabiting forest species Lentinula edodes, while still attached to their mycelium and substrate, to artificial solar light (ca. 30 °C and 100.000 lux) for 5, 30, and 60 minutes. We found significant differentially expressed genes at 30 and 60 minutes. Eukaryotic Orthologous Groups (KOG) class enrichment pointed to defense mechanisms. The 20 most significant differentially expressed genes showed the expression of heat-shock proteins, an important family of proteins under heat stress. Although preliminary, our results suggest mushroom-specific molecular responses to tolerate enhanced sun exposure as expected under climate change. Whether mushroom-specific molecular responses are able to maintain fungal fitness under opening forest canopies remains to be tested.

openother-openJul 2022View details →

Cutaneous Evaporative Water Loss in Lizards is Variable across Body Regions and Plastic in Response to Humidity

Data and code associated with the 2022 publication in Herpetologica (doi:10.1655/Herpetologica-D-21-00030.1).

opencc-by-4.0Feb 2023View details →

Terminus Traces for publication 'Ocean-forcing and glacier-specific factors drive differing glacier response across the 69 oN boundary, east Greenland' (Version 1)

Dataset supporting publication 'Brough, S., Carr, J.R., Ross, N., Lea, J.M. (2023) Ocean-forcing and glacier-specific factors drive differing glacier response across the 69 oN boundary, east Greenland. J. Geophys. Res. Earth Surf. <a href="https://doi.org/10.1029/2022JF006857">https://doi.org/10.1029/2022JF006857</a>.' This dataset provides GIS ready shapefiles of mapped terminus traces for 24 east Greenland glaciers between 2013 and 2020 for the aforementioned publication. Data are provided in both geographic (EPSG: 4326; WGS84) and projected (EPSG:3413; NSIDC Sea Ice Polar Stereographic North) coordinate systems. As each terminus trace has metadata appended, including the unique path identifier, it is possible to directly and easily identify the original image used in the mapping process. Both shapefiles are compatible for ingestion into the Google Earth Digitisation Tool (GEEDiT) Reviewer (<a href="https://liverpoolgee.wordpress.com/">https://liverpoolgee.wordpress.com/</a>) for reviewing and sub-setting the dataset (see Lea, J.M. [2018] Earth Surf. Dynam. 6, 551–561. <a href="https://doi.org/10.5194/esurf-6-551-2018">https://doi.org/10.5194/esurf-6-551-2018</a>).   When using this data product in a publication, please include the following citations: Brough, S., Carr, J.R., Ross, N., Lea, J.M. (2023). Terminus Traces for publication 'Ocean-forcing and glacier-specific factors drive differing glacier response across the 69 oN boundary, east Greenland' (Version 1) [Data set]. Zenodo. <a href="https://doi.org/10.5281/zenodo.6904219">https://doi.org/10.5281/zenodo.6904219</a>. Brough, S., Carr, J.R., Ross, N., Lea, J.M. (2023) Ocean-forcing and glacier-specific factors drive differing glacier response across the 69 oN boundary, east Greenland.  J. Geophys. Res. Earth Surf. <a href="https://doi.org/10.1029/2022JF006857">https://doi.org/10.1029/2022JF006857</a>.

opencc-by-4.0Jul 2022View details →

Obesity and acute stress modulate appetite and neural responses in food word reactivity task

Data used in "Carnell S, Benson L, Papantoni A, Chen L, Huo Y, Wang Z, Peterson BS, Geliebter A. Obesity and acute stress modulate appetite and neural responses in food word reactivity task. PloS one"

Dataset: Inverse responses of species richness and niche specialization to human development

Humans impact biodiversity by altering land use and introducing nonnative species. Yet the extent to which coexistence processes, such as competition and niche shifts, mediate these relationships is not clear. This dataset was used in a study that aims to compare how human development influences wetland plant diversity by examining patterns of species richness, niche specialization, and nonnative species occurrences along a human development gradient. This dataset can be used to analyzed species richness and niche specialization (a measure of the range of human development extents over which a species occurs) patterns from species occurrence data across 1582 wetlands in Alberta, Canada. Associations between human development extent and species richness, niche specialization, and nonnative species can be tested using linear mixed models. Also, nonmetric multidimensional scaling ordination can be applied from raw data (see usage notes) to examine whether community composition differed among wetlands surrounded by different human development extents. Note that human development data are accessible only through a data sharing agreement with ABMI. See the readme document for more details on how to obtain assess to these data. Results of these analyses can be found in the corresponding publication: Inverse responses of species richness and niche specialization to human development, Journal of Biogeography. https://doi.org/10.1111/jbi.14240 <ul> </ul>

Machine learning on syngeneic mouse tumor profiles to model clinical immunotherapy response

Most cancer patients are refractory to immune checkpoint blockade (ICB) therapy, and proper patient stratification remains an open question. Primary patient data suffer from high heterogeneity, low accessibility, and lack of proper controls. In contrast, syngeneic mouse tumor models enable controlled experiments with ICB treatments. Using transcriptomic and experimental variables from >700 ICB-treated/control syngeneic mouse tumors, we developed a novel machine learning framework to model tumor immunity and identify factors influencing ICB response. Projected on human immunotherapy trial data, we found that the model can predict clinical ICB response. We further applied the model to predicting ICB-responsive/resistant cancer types in TCGA, which agreed well with existing clinical reports. Finally, feature analysis implicated factors associated with ICB response. In summary, our novel computational framework based on mouse tumor data reliably stratified patients regarding ICB response, informed resistance mechanisms, and has the potential for wide applications in disease treatment studies.

Plant root growth against a mechanical obstacle: The early growth response of a maize root facing an axial resistance is consistent with the Lockhart model

Plant root growth is dramatically reduced in compacted soils, affecting the growth of the whole plant. Through a model experiment coupling force and kinematics measurements, we probed the force-growth relationship of a primary root contacting a stiff resisting obstacle, that mimics the strongest soil impedance variation encountered by a growing root. The growth of maize roots just emerging from a corseting agarose gel and contacting a force sensor (acting as an obstacle) was monitored by time-lapse imaging simultaneously to the force. The evolution of the velocity field along the root was obtained from kinematics analysis of the root texture with a PIV derived-technique. A triangular fit was introduced to retrieve the elemental elongation rate or strain rate. A parameter-free model based on the Lockhart law quantitatively predicts how the force at the obstacle modifies several features of the growth distribution (length of the growth zone, maximal elemental elongation rate, velocity) during the first 10 minutes. These results suggest a strong similarity of the early growth responses elicited either by a directional stress (contact) or by an isotropic perturbation (hyperosmotic bath).