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1,047 results for “constraint”
Data from: Constraints on song type matching in a songbird
In an eastern population of song sparrows (Melospiza melodia), song type matching occurs at above chance levels but does not signal aggressiveness. One explanation for the apparent ineffectiveness of matching as a signal is that the occurrence of matching is constrained by internal rules for ordering the production of song types. This constraint hypothesis is tested here in an experiment in which the singing of territorial male song sparrows is monitored in the field in real time, and subjects are confronted with playback of one of their song types either immediately after switching away from that type (short delay) or after having cycled through much of their repertoire since last singing that type (long delay). Matching was not significantly more likely in the long delay treatment than in the short delay treatment. The probability of matching did, however, depend significantly on prior bout length: the longer was a singer's last bout of a song type, the less likely the singer was to match it. There was also a suggestive effect of frequency of usage: males were more likely to match a song type the more frequently they normally sang that type, though this result was not significant after correcting for multiple comparisons. Thus, internal rules on how songs are sequenced exert constraints on the occurrence of song type matching, and such constraints can help to explain the apparent ineffectiveness of matching as a signal in this study population.
Data from: Constraints on fruit-tracking by birds at the range edge
Aims: Biotic interactions may be disrupted at the range boundary if the involved species are rare in the most distant sectors. This study assesses fruit-tracking by seed-dispersing birds wintering on the border of the Palaearctic, a region where many species become scarcer before reaching the limits of their distribution in the Sahara. Since vagrancy improves fruit-tracking, this study tests if vagrant birds track fruit resources better than non-vagrant birds and if their tracking ability is reduced at the range edge. Location: The Iberian Peninsula and the Maghreb Methods: Seed-dispersing passerines (O. Passeriformes) were counted in 134 sampling sites along a 2000 km long latitudinal belt. Relationships between bird numbers and latitude, temperature, shrub cover and fruit abundance were explored by multivariate analyses. In addition, the habitat matching rule was used to assess the ability of birds to track fruit changes along the latitudinal belt. Results: Fruit abundance and temperature were the main drivers of the distribution of vagrant birds (all of them migratory species) while for non-vagrant birds (most of them sedentary species) distribution was weakly correlated to the study variables. Vagrant birds tracked the spatial-temporal variations in fruit abundance but showed a reduced ability to fit numbers to fruit abundance changes in southern sectors. Main conclusions: Vagrant, migratory birds are responsible for large-scale tracking of fruit outputs but face some constraints on fruit-tracking at the far edge of the Palaearctic. Since the movements of these birds southwards are declining due to climate warming effects, these results suggest a future weakening of their role as seed dispersers in the most peripheral areas of the Palaearctic.
Evolutionary trade-offs may interact with physiological constraints to maintain color variation
<p>Animal coloration is a multifaceted trait with many ecological roles and related to a variety of developmental and physiological processes. Consequently, coloration is often subject to a variety of selective pressures, leading to the evolutionary maintenance of variation. In this study, we investigated hypotheses related to the maintenance of dorsal color variation in wood frogs (<i>Rana sylvatica</i>). First, we tested for multimodality, and whether color correlates with body size or condition or varies by sex or age-class. We combined behavioral trials with visual modeling to test for sex recognition. We also considered visual models for predators and tested for an interaction between discriminability indexes (JND) of color channel (chromatic vs. achromatic) and predator type (birds vs. snakes), as well as for a within individual trade-off between the JND of chromatic and achromatic coloration. Finally, we tested for disruptive viability selection on color using predation trials, and for antagonistic directional selection between viability selection and reproductive investment of females. We found that wood frogs present continuous color variation that does not correlate with body size or condition, but that changes with age. Wood frogs present subtle sexual dichromatism, but we found no evidence for a role of color in sex recognition. Instead, we discuss the possibility that sex differences might, at least in part, have a demographic explanation. Predator visual models indicated that wood frogs cannot solely rely on dorsal coloration for camouflage. Moreover, different predators might present selective pressures in different color channels, while individuals' achromatic and chromatic coloration trade-off in JND. Therefore, different selective pressures caused by different predators might interact with ontogenetic changes and developmental/physiological trade-offs to maintain color variation. We found no relationship between color and survival or reproductive investment, suggesting further work is required to fully understand selection on color. Our results highlight the importance of understanding evolutionary trade-offs and developmental/physiological constraints in combination with one another, and suggest the potential for an interaction between these proximate and ultimate mechanisms in the evolutionary maintenance of variation. These results likely extend beyond color expression in amphibians, and exemplify a more general process for such evolutionary outcomes.</p>
Datasets for Mixed support for gene flow as a constraint to local adaptation and contributor to the limited geographic range of an endemic salamander
<p>Understanding mechanisms that underlie species range limits is at the core of evolutionary ecology. Asymmetric gene flow between larger core populations and smaller edge populations can swamp local adaptation at the range edge and inhibit further range expansion. However, empirical tests of this theory are exceedingly rare. We tested the hypothesis that asymmetric gene flow can constrain local adaptation and thereby species' range limits in an endemic US salamander (<i>Ambystoma barbouri</i>) by determining if gene flow is asymmetric between the core and peripheries of the species' geographic distribution and testing whether local adaptation is swamped at range edges with a reciprocal transplant experiment. Using putatively neutral loci from populations across three core-to-edge transects that covered nearly the entire species' geographic range, we found evidence for asymmetric, core-to-edge gene flow along western and northern transects, but not along a southern transect. Subsequently, the reciprocal transplant experiment suggested that northern and western edge populations are locally adapted despite experiencing asymmetric gene flow yet have lower fitness in their respective home regions than center populations do. Conversely, southern populations exhibit low deme quality, experiencing high mortality regardless of where they were reared, likely due to harsher edge habitat conditions. Consequently, we provide rare species-wide evidence that local adaptation can occur despite asymmetric gene flow, though migration from the core may prohibit range expansion by reducing fitness in edge populations. Further, our multi-transect study shows that multiple, non-mutually exclusive mechanisms can lead to range limits within a single species.</p>
Allometric escape from acoustic constraints in frog calls is rare
<p class="AbstractSummary">Allometric constraint is a product of natural selection, particularly with respect to body size and traits constrained by physical properties thereof, such as metabolism, longevity, and vocal frequency. Parameters describing allometric relationships are conserved across most lineages, indicating that physical constraints dictate scaling patterns in deep time, despite substantial genetic and ecological divergence among organisms. Acoustic allometry (sound frequency ~ body size) is conserved across frogs, in defiance of massive variation in both body size and frequency. Here, we find four major instances of allometric escape, potentially deriving from ecomorphological adaptations to new signal modalities and invasion of biogeographic regions. In these instances of allometric escape, the optima and strength of the scaling relationship are different than expected for most other frog species, representing new adaptive regimes of body size ~ call frequency. Allometric constraints in frogs are highly conserved and have rarely promoted allometric escape despite frequent invasions of new adaptive regimes and dramatic ecomorphological divergence. Our results highlight instances in which natural and sexual selection combined could overcome physical constraints on sound production.</p>
Breaking Free from Thermodynamic Constraints: Thermal Acclimation and Metabolic Compensation in a freshwater zooplankton species
<p>Ectothermic organisms' respiration rates are largely controlled by environment temperatures and the ability to meet metabolic demands at high temperatures sometimes sets their upper thermal limit. Organisms are hypothesized to exhibit acclimatory effects, adjusting their metabolism and physiology by deceleration of metabolic processes including respiration below Arrhenius expectations based in temperature alone. Such deceleration is termed metabolic compensation. We test the hypothesis that either heritable (among genotypes) or plastic (between acclimation regimes) heat tolerance differences can be explained by metabolic compensation in the eurythermal freshwater zooplankton crustacean Daphnia magna. We measured oxygen consumption rates over a range of assay temperatures (5°C - 37°C) in 8 genotypes of Daphnia representing a range of previously reported genotype-specific acute heat tolerance values and, in a narrower range of temperatures (10°C - 35°C) in Daphnia with different acclimation history (either 10°C or 25°C). In a ramp-up experiment we discovered no difference in temperature-specific respiration rates between heat tolerant and heat-sensitive genotypes. In contrast, we observed compensatory differences in respiration rates at both extremes of the temperature range studied. Notably, there was a deceleration of oxygen consumption at higher temperature in the 25°C-acclimated Daphnia relative to their 10°C-acclimated counterparts, observed in active, but not anaesthetized animals, a pattern corroborated by similar changes in filtering rate and, partly, by changes in mitochondrial membrane potential. Daphnia exposed to a sublethal temperature (35°C) with a 24-hour recovery period at a 25°C-acclimation temperature showed no difference in respiration compared to unexposed 25°C-acclimated Daphnia, indicating that the reduction of respiration is not caused by irreversible damage. Response time necessary to acquire the respiratory adjustment to high temperature was much lower than to low temperature, indicating that metabolic compensation at the lower temperatures require slower structural changes.</p>
Seasonal time constraints shape life history, physiology and behaviour independently, and decouple a behavioural syndrome in a damselfly
The integration of traits into 'syndromes' has been suggested as a useful framework to advance insights in trait responses to environmental stressors. Yet, how stressors shape the consistency ('repeatability') of traits and their covariation at the individual level remains debated. We studied how seasonal time constraints shape trait repeatability and integration of life-history, behavioural, and physiological traits along a fast-slow continuum, using the 'pace-of-life syndrome' as a framework. We manipulated the photoperiod during the larval development of the damselfly Ischnura elegans, generating a time-relaxed early, a control, and a time-constrained late group. The photoperiod treatment did not seem to affect the voltinism of the larvae. As predicted, late-period larvae accelerated development and growth, yet this acceleration was no longer detectable for growth and metabolic rate during the final instar, possibly due to costs of the initial life-history acceleration. This warrants caution when inferring a species' pace-of-life based on a specific developmental stage. The late-period larvae were as predicted more active (only during the later stages of the final instar) and bolder than the control larvae, but not different from the early-period larvae. Most studies on time constraints only compared late and control animals, thereby potentially wrongly concluding adaptive responses to time constraints. Activity, boldness, and body mass were repeatable, while growth and metabolic rates were not. Notably, repeatabilities did not change under time constraints. There was no support for an overall trait integration in a pace-of-life syndrome, yet activity and boldness covaried positively as expected. Importantly, this 'behavioural syndrome' was decoupled in the late-period larvae, which might be adaptive to enhance energy acquisition to fuel the accelerated development rate. Our results suggest that besides the predicted plastic acceleration of life-history, plastic changes in behavioural trait integration may also be an important but overlooked adaptive aspect of responding to time constraints.
Dataset and analyses for: Active foot placement control ensures stable gait: Effect of constraints on foot placement and ankle moments
<p>For this dataset kinematics, ground reaction forces and electromyography data were collected during human treadmill walking. Participants walked on the treadmill at normal and slow walking speed, across different conditions. Apart from unconstrained steady-state walking, these conditions included imposed foot placement and ankle moment constraints. In our analysis we focused on the coupling between CoM kinematic state and foot placement, as well as correlations with muscle activity, reflecting active foot placement control.</p> <p>The results have been presented and discussed in the paper entitled: Active foot placement control ensures stable gait: Effect of constraints on foot placement and ankle moments.</p> <p>Guidelines on how to use this code can be found in the word file "Documentation", which can be found in the zipped folder.</p>
The geometry of resource constraint: an empirical study of the golden snub-nosed monkey
<p>1. Apposite conceptualization and measurement of resource variation is critical for understanding many issues in ecology, including ecological niches, persistence and distribution of populations, the structure of communities, and population resilience to perturbations.</p> <p>2. We apply the nutritional geometry framework to conceptualise and quantify the responses of a temperate-living primate, the golden snub-nosed monkey (<i>R</i><i>hinopithecus</i><i> roxellana</i>) to variation in resource quality and quantity and in nutrient requirements associated with seasonal environments.</p> <p>3. We present a geometric model distinguishing qualitative constraint, quantitative constraint, and "pseudo-constraint" whereby nutrient intakes resemble response to qualitative resource constraint but are in fact driven by variation in nutrient requirements. The model is applied to analyse nutrient intakes recorded in 164 full day observations of monkeys from two populations, one wild and the other captive, across seasons. Additionally, we recorded the diet of a single animal over 32 consecutive days in the wild.</p> <p>4. Despite considerable differences in available resources, the captive and wild populations showed marked similarities in nutrient intakes, including indistinguishable amounts and ratios of ingested macronutrients during summer and autumn and strong year-round maintenance of protein compared to seasonally variable fat and carbohydrate intakes. These similarities suggest homeostatically regulated nutritional targets and provide reference points to identify factors driving population differences in macronutrient intake in winter and spring.</p> <p>5. Our framework enabled us to distinguish examples of quantitative, qualitative, and "pseudo-constraint". We suggest that this approach can increase the resolution at which resource constraint is conceptualised and measured in ecological studies.</p>
Data from: Multiple constraints cause positive and negative feedbacks limiting grassland soil CO2 efflux under CO2 enrichment
<p>Terrestrial ecosystems are increasingly enriched with resources such as atmospheric CO<sub>2</sub> that limit ecosystem processes. The consequences for ecosystem carbon cycling depend on the feedbacks from other limiting resources and plant community change, which remain poorly understood for soil CO<sub>2</sub> efflux, J<sub>CO2</sub>, a primary carbon flux from the biosphere to the atmosphere. We applied a unique CO<sub>2</sub> enrichment gradient (250 to 500 µL L<sup>-1</sup>) for eight years to grassland plant communities on soils from different landscape positions. We identified the trajectory of J<sub>CO2</sub> responses and feedbacks from other resources, plant diversity (effective species richness, exp(H)), and community change (plant species turnover). We found linear increases in J<sub>CO2</sub> on an alluvial sandy loam and a lowland clay soil, and an asymptotic increase on an upland silty clay soil. Structural equation modelling identified CO<sub>2</sub> as the dominant limitation on J<sub>CO2</sub> on the clay soil. In contrast with theory predicting limitation from a single limiting factor, the linear J<sub>CO2</sub> response on the sandy loam was reinforced by positive feedbacks from aboveground net primary productivity and exp(H), while the asymptotic J<sub>CO2</sub> response on the silty clay arose from a net negative feedback among exp(H), species turnover, and soil water potential. These findings support a multiple resource limitation view of the effects of global change drivers on grassland ecosystem carbon cycling and highlight a crucial role for positive or negative feedbacks between limiting resources and plant community structure. Incorporating these feedbacks will improve models of terrestrial carbon sequestration and ecosystem services.</p>
Data for Hydrogeochemical constraints shape hot spring microbial community compositions: Evidence from acidic, moderate-temperature springs and alkaline, high-temperature springs, southwestern Yunnan geothermal areas, China
<p>Original data for <strong>Hydrogeochemical constraints shape hot spring microbial community compositions: Evidence from acidic, moderate-temperature springs and alkaline, high-temperature springs, southwestern Yunnan geothermal areas, China. </strong></p>
Data from: Saprotrophic and ectomycorrhizal fungal sporocarp stoichiometry (C : N : P) across temperate rainforests as evidence of shared nutrient constraints among symbionts
Summary: Quantifying nutritional dynamics of free-living saprotrophs and symbiotic ectomycorrhizal fungi (EMF) in the field is challenging, but the stoichiometry of fruiting bodies (sporocarps) may be an effective methodology for this purpose. Carbon (C), nitrogen (N), and phosphorus (P) concentrations of soils, foliage and 146 sporocarp collections were analyzed from 14 Pseudotsuga menziesii var. menziesii stands across a podzolization gradient on Vancouver Island (Canada). N and P concentrations were considerably higher in saprotrophic fungi. Fungal N% increased with soil N content at a greater rate for saprotrophs than EMF, while fungal P% of saprotrophs was more constrained. Fungal N:P was more responsive to soil N:P for EMF (homeostatic regulation coefficient 'H' =2.9) than saprotrophs (H= 5.9), while N:P of EMF and host tree foliage scaled almost identically. Results underscore the role of EMF as nutrient conduits, supporting host trees, whereas saprotrophs maintain a greater degree of nutritional homeostasis. Site nutrient constraints were shared in equal measure between EMF and host trees, particularly for P, suggesting neither partner benefits from enhanced nutrition at the expense of the other. Sporocarp stoichiometry provides new insights into mycorrhizal relationships and illustrates pervasive P deficiencies across temperate rainforests of the Pacific Northwest.
Data from: Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters
1. Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint (Ci) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits). 2. Here we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, e.g., on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities. 3. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations). 4. The relative ease of calculation and dimensionless nature of Ci allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints i) among communities from different regions, ii) on different traits across similar environmental gradients, and iii) for the same trait across different gradient-types.
Phytoplankton thermal responses adapt in the absence of hard thermodynamic constraints
To better predict how populations and communities respond to climatic temperature variation, it is necessary to understand how the shape of the response of fitness-related rates to temperature evolves (the thermal performance curve). Currently, there is disagreement about the extent to which the evolution of thermal performance curves is constrained. One school of thought has argued for the prevalence of thermodynamic constraints through enzyme kinetics, whereas another argues that adaptation can—at least partly—overcome such constraints. To shed further light on this debate, we perform a phylogenetic meta-analysis of the thermal performance curves of growth rate of phytoplankton—a globally important functional group—, controlling for environmental effects (habitat type and thermal regime). We find that thermodynamic constraints have a minor influence on the shape of the curve. In particular, we detect a very weak increase of maximum performance with the temperature at which the curve peaks, suggesting a weak "hotter-is-better" constraint. Also, instead of a constant thermal sensitivity of growth across species, as might be expected from strong constraints, we find that all aspects of the thermal performance curve evolve along the phylogeny. Our results suggest that phytoplankton thermal performance curves adapt to thermal environments largely in the absence of hard thermodynamic constraints.
Data from: Evidence for repeated loss of selective constraint in rhodopsin of amblyopsid cavefishes (Teleostei: Amblyopsidae)
The genetic mechanisms underlying regressive evolution—the degeneration or loss of a derived trait—are largely unknown, particularly for complex structures such as eyes in cave organisms. In several eyeless animals, the visual photoreceptor rhodopsin appeared to retain functional amino-acid sequences. Hypotheses to explain apparent maintenance of function include weak selection for retention of light-sensing abilities and its pleiotropic roles in circadian rhythms and thermotaxis. In contrast, we show that there has been repeated loss of functional constraint of rhodopsin in amblyopsid cavefishes, as at least three cave lineages have independently accumulated unique loss-of-function mutations over the last 10.3 My. While several cave lineages still possess functional rhodopsin, they exhibit increased rates of nonsynonymous mutations that have greater effect on the structure and function of rhodopsin compared to those in surface lineages. These results indicate that functionality of rhodopsin has been repeatedly lost in amblyopsid cavefishes. The presence of a functional copy of rhodopsin in some cave lineages is likely explained by stochastic accumulation of mutations following recent subterranean colonization.
Data from: Do evolutionary constraints on thermal performance manifest at different organizational scales?
The two foremost hypotheses on the evolutionary constraints on an organism's thermal sensitivity – the hotter-is-better expectation, and the specialist–generalist trade-off – have received mixed support from empirical studies testing for their existence. Could these conflicting results reflect confusion regarding the organizational level (i.e. species > population > individual) at which these constraints should manifest? We propose that these evolutionary constraints should manifest at different organizational levels because of differences in their underlying causes and requirements. The hotter-is-better expectation should only manifest across separate evolutionary units (e.g. species, populations), and not within populations. The specialist–generalist trade-off, by contrast, should manifest within as well as between separate evolutionary units. We measured the thermal sensitivity of sprint performance for 440 rainforest sun skinks (Lampropholis coggeri) representing 10 populations, and used the resulting performance curves to test for evidence for the hypothesized constraints at two organizational levels: (i) across populations and (ii) within populations. As predicted, the hotter-is-better expectation was evident only at the across-population level, whereas the specialist–generalist trade-off was evident within, as well as across, populations. Our results suggest that, depending on the processes that drive them, evolutionary constraints can manifest at different organizational levels. Consideration of these underlying processes, and the organizational level at which a constraint should manifest, may help resolve conflicting empirical results.
Data from: Architectural constraints, male fertility variation and biased floral morph ratios in tristylous populations
Tristyly is a genetic polymorphism in which populations are comprised of three floral morphs (mating types) differing reciprocally in sex-organ height. Intermorph (disassortative) mating governed by a trimorphic incompatibility system should result in 1:1:1 morph ratio at equilibrium, but both deterministic and stochastic processes can cause skewed morph ratios in tristylous populations. Here, we investigate mechanisms causing morph-ratio bias in Pontederia parviflora, an emergent aquatic native to tropical America. We compared reproductive traits among morphs and surveyed 71 populations to determine patterns of morph-ratio bias. We then used simulation models of morph-frequency dynamics to test the hypothesis that morph-specific differences in pollen production and their influence on male fertility can explain patterns of morph-ratio bias. Ninety-seven percent of populations that we sampled were tristylous, but with a significant excess of the short-styled morph and a deficiency of the long-styled morph. Atypically for a tristylous species, mid-level anthers of the short-styled morph produced over twice as much pollen compared with the corresponding anthers of the long-styled morph. Our computer models incorporating this difference in male fertility resulted in morph ratios not significantly different from the average frequencies from our survey suggesting that the short-styled morph is more successful than the long-styled morphs in siring ovules of the mid-styled morph. We propose that the difference in male fertility between morphs may be a non-adaptive consequence of a developmental constraint caused by the architecture of tristyly in Pontederiaceae.
Data from: Acoustic identification of Mexican bats based on taxonomic and ecological constraints on call design
Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in megadiverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4685 search-phase calls from 1378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus and guild). Species-level classification of calls had a mean accuracy of 66%, and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71·2% and species within guilds 69·1%). Classification accuracy to family, genus and guild-level was 91·7%, 77·8% and 82·5%, respectively. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioacoustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico.
Data from: Appearance before performance? Nutritional constraints on life-history traits, but not warning signal expression in aposematic moths
1. Trade-offs have been shown to play an important role in the divergence of mating strategies and sexual ornamentation, but their importance in explaining warning signal diversity has received less attention. In aposematic organisms, allocation costs of producing the conspicuous warning signal pigmentation under nutritional stress could potentially trade-off with life-history traits and maintain variation in warning colouration. 2. We studied this with an aposematic herbivore Arctia plantaginis (Arctiidae), whose larvae and adults show extensive variation in aposematic colouration. In larvae, less melanic colouration (i.e. larger orange patterns) produces a more efficient warning signal against predators, whereas high amounts of melanism (smaller orange pattern) enhance thermoregulation, correlate with better immunity and make individuals harder to detect for naïve predators. 3. We conducted a factorial rearing experiment with larvae originating from lines selected for either small or large orange signal size, which were reared on an artificial diet that had either low or high protein content. Protein content of the diet is critical for melanin production. We measured the effects of diet on individual colouration, life-history traits, immune defence and reproductive output. We also compared the responses to dietary conditions between the small and large larval signal genotypes. 4. Protein content of the diet did not affect warning colouration in the larval stage, but larval signal sizes differed significantly among selection lines, confirming that its variation is mainly genetically determined. In adults, signal line or diet did not affect colouration in hindwings, but males' forewings had more melanin on the high than on low protein diet. Contrary to colouration, diet quality had a stronger impact on life-history traits: individuals developed for longer, had smaller hindwing sizes in females and lower immune defence on the low protein content diet compared to the high. These costs were higher for more melanic larval signal genotypes in terms of development time and female hindwing size. 5. We conclude that low plasticity in warning signal characteristics makes signal expression robust under varying dietary conditions. Therefore, variation in diet quality is not likely to constrain signal expression, but can have a bigger impact on performance.
Data from: Oncogene inference optimization using constraint-based modelling incorporated with protein expression in normal and tumour tissues
Cancer cells are known to exhibit unusual metabolic activity and yet, few metabolic cancer driver genes are known. Genetic alterations and epigenetic modi cations of cancer cells result in the abnormal regulation of cellular metabolic pathways that are different when compared to normal cells. Such a metabolic reprogramming can be simulated using constraint-based modelling approaches towards predicting oncogenes. We introduced the tri-level optimization problem to use the metabolic reprogramming towards inferring oncogenes. The algorithm incorporated Recon 2.2 network with the Human Protein Atlas to reconstruct genome-scale metabolic network models of the tissue-speci fic cells at normal and cancer states, respectively. Such reconstructed models were applied to build the templates of the metabolic reprogramming between normal and cancer cell metabolism. The inference optimization problem was formulated to use the templates as a measure towards predicting oncogenes. The nested hybrid differential evolution algorithm was applied to solve the problem to overcome solving difficulty for transferring the inner optimization problem into the single one. Head and neck squamous cells were applied as a case study to evaluate the algorithm. We detected 13 of the top ranked one-hit dysregulations and 17 of the top ranked two-hit oncogenes with high similarity ratios to the templates. According literature survey, most inferred oncogenes are consistent with the observation in various tissues. Furthermore, the inferred oncogenes were highly connected with the TP53/AKT/IGF/MTOR signalling pathway through PTEN, which is one of the most frequently detected tumour suppressor genes in human cancer.
ScienceDex guides
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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.