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1,610 results for “ratio”

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dryad32/100

Data from: Protoporphyrin-based eggshell pigmentation is associated with female plumage colouration and predicts offspring sex ratio in the barn swallow

Inter- and intraspecific variation in eggshell colouration has long fascinated evolutionary biologists. Among species, such variation may accomplish different functions, the most obvious of which is camouflage and background matching. Within species, it has been proposed that inter-female variation in eggshell pigmentation patterns can reflect egg, maternal or paternal traits and hence may provide cues to conspecifics about egg, maternal or paternal phenotypic quality. However, the relationship between protoporphyrin-based eggshell pigmentation and egg or maternal/paternal traits appears to be highly variable among species. We investigated patterns of intraspecific variation in Eurasian barn swallow (Hirundo r. rustica) protoporphyrin-based eggshell pigmentation, and analysed its association with egg and clutch characteristics, maternal/paternal phenotypic traits and parental feeding effort. Eggshell pigmentation pattern significantly varied between breeding colonies, was significantly repeatable in clutches laid by the same females in different years (intraclass correlation coefficient ranging between 0.56 and 0.63), but it was not significantly associated with egg traits, such as position in the laying sequence, egg mass, yolk testosterone concentration and antioxidant capacity. It was weakly or non-significantly associated with female and male traits (sexual ornaments), but females laying darker (higher pigment intensity) first clutches had higher hatching success, suggesting that eggshell pigment intensity may predict fitness. Nevertheless, males did not significantly modulate their parental nestling feeding effort accordingly. In addition, females with darker breast plumage colouration (a melanin-based trait related to fitness) laid highly protoporphyrin-covered eggs, suggesting the presence of a previously unappreciated link between protoporphyrin biosynthesis and plumage melanisation. Moreover, the proportion of male offspring increased in clutches originating from highly protoporphyrin-covered eggs, suggesting that parents could acquire visual cues about their future brood sex composition before egg hatching. Our results support the idea that intraspecific signalling via eggshell pigmentation is a species-specific rather than a general feature of avian taxa.

opencc-zeroDec 2017View details →
dryad32/100

Data from: Sons do not take advantage of a head start: parity in herring gull offspring sex ratios despite greater initial investment in males

Skewed adult sex ratios sometimes occur in populations of free-living animals yet the proximate mechanisms, timing of sex-biases, and the selective agents contributing to skew remain a source of debate with contradictory evidence from different systems. We investigated potential mechanisms contributing to sex biases in a population of herring gulls with an apparent female skew in the adult population. Theory predicts that skewed adult sex ratios will adaptively lead to skewed offspring sex ratios to restore balance in the effective breeding population. Parents may also adaptively bias offspring sex ratios to increase their own fitness in response to environmental factors. Therefore, we expected to detect skewed sex ratios either at hatching or at fledging as parents invest differentially in offspring of different sexes. We sampled complete clutches (n = 336 chicks) at hatching to quantify potential skews in sex ratios by position in the hatch order, time of season, year, and nesting context (nest density), finding no departure from equal sex ratios at hatching related to any of these factors. Further, we sampled 258 chicks at near-fledging to investigate potential sex biases in survival at the chick stage. Again, no biases in sex ratios were recorded. Male offspring were favored in this population via greater maternal investment in eggs carrying male embryos and greater parental provisioning of male offspring which reached greater sizes by fledging. Despite the advantages realized by male offspring, females were equally as likely to fledge as males. Thus, biased adult sex ratios apparently arise in the post-fledging and pre-recruitment stage in our population.

opencc-zeroDec 2014View details →
dryad32/100

Data from: The spatial ecology of sex ratios in a dioecious plant: relations between ramet and genet sex ratios

1. In clonal dioecious plants, the frequency and spatial distribution of flowering ramets contains information on the underlying genet sex ratio. These measures can also provide insight on potential ecological mechanisms causing variation and bias in sex ratios among populations. 2. We used a novel likelihood-based approach and spatial clustering model to estimate the genet sex ratios from flowering ramet data collected from 32 populations of dioecious Thalictrum pubescens, a clonal species from eastern N. America that occupies moist wetland and forested environments. We investigated sex ratios of seed families, clone size, patterns of flowering and plant height to determine potential causes of sex ratio bias. 3. Flowering ramet sex ratios varied considerably among populations but were significantly male-biased. Seed families grown to flowering also exhibited the same degree of male bias. Both models predicted close correspondence between ramet and genet sex ratios. The likelihood model revealed that gender differences in ramet production could not account for biased sex ratios. The spatial clustering model indicated that ramets were significantly clustered at two spatial scales and estimated similar cluster sizes and densities for both sexes. There was no evidence for spatial segregation of the sexes. Both sexes were equally likely to flower in consecutive years and repeated bouts of flowering had no effect on ramet height. 4. Synthesis. Our analyses suggest that the widespread occurrence of male-biased sex ratios in T. pubescens is unlikely to result from sexual differences in clonal growth or habitat preferences. The bias appears to become established early in the life cycle, perhaps at the seed stage as consequence of local resource competition.

opencc-zeroDec 2018View details →
dryad32/100

Data from: Sex ratio effects on reproductive strategies in humans

Characterizations of coy females and ardent males are rooted in models of sexual selection that are increasingly outdated. Evolutionary feedbacks can strongly influence the sex roles and subsequent patterns of sex differentiated investment in mating effort, with a key component being the adult sex ratio (ASR). Using data from eight Makushi communities of southern Guyana, characterized by varying ASRs contingent on migration, we show that even within a single ethnic group, male mating effort varies in predictable ways with the ASR. At male-biased sex ratios, men's and women's investment in mating effort are indistinguishable; only when men are in the minority are they more inclined towards short-term, low investment relationships than women. Our results support the behavioural ecological tenet that reproductive strategies are predictable and contingent on varying situational factors.

opencc-zeroDec 2013View details →
dryad32/100

Data from: Caste ratios affect the reproductive output of social trematode colonies

Intraspecific phenotypic diversification in social organisms often leads to formation of physical castes which are morphologically specialised for particular tasks within the colony. The optimal caste allocation theory argues that specialised morphological castes are efficient at specific tasks, and hence different caste ratios should affect the ergonomic efficiency, hence reproductive output of the colony. However, the reproductive output of different caste ratios has been documented only in few species of insects with equivocal support for the theory. The present study investigated whether the ratios of non-reproductive and reproductive morphs affect the reproductive output of a recently discovered social trematode, Philophthalmus sp., in which the non-reproductive members are hypothesized to be defensive specialists. Census of natural infections and a manipulative in-vitro experiment demonstrated a positive association between the reproductive output of trematode colonies and the ratio of non-reproductive to reproductive morphs in the presence of an intra-host trematode competitor, Maritrema novaezealandensis. On the contrary, without the competitor, reproductive output was negatively associated with the proportion of non-reproductive castes in colonies. Our findings demonstrate for the first time a clear fitness benefit associated with the non-reproductive castes in the presence of a competitor while illustrating the cost of maintaining such morphs in non-competitive situations. Although the proximate mechanisms controlling caste ratio remain unclear in this trematode system, the present study supports the prediction that the fitness of colonies is influenced by the composition of specialized functional morphs in social organisms, suggesting a potential for adaptive shifts of caste ratios over evolutionary time.

opencc-zeroDec 2011View details →
dryad32/100

Data from: Light and growth form interact to shape stomatal ratio among British angiosperms

In most plants, stomata are located only on the abaxial leaf surface (hypostomy), but many plants have stomata on both surfaces (amphistomy). High light and herbaceous growth form have been hypothesized to favor amphistomy, but these hypotheses have not been rigorously tested together using phylogenetic comparative methods. I leveraged a large dataset including stomatal ratio, Ellenberg light indicator value, growth form and phylogenetic relationships for 372 species of British angiosperms. I used phylogenetic comparative methods to test how light and/or growth form influence stomatal ratio and density. High light and herbaceous growth form are correlated with amphistomy, as predicted, but they also interact; the effect of light is pronounced in therophytes (annuals) and perennial herbs, but muted in phanerophytes (shrubs and trees). Furthermore, amphistomy and stomatal density evolve together in response to light. Comparative analyses of British angiosperms reveal two major insights. First, light and growth form interact to shape stomatal ratio; amphistomy is common under high light, but mostly for herbs. Second, coordinated evolution of adaxial stomatal density and light tolerance indicates that amphistomy helps to optimally balance light acquisition with gas exchange. Stomatal ratio may have potential as a functional trait for paleoecology and crop improvement.

opencc-zeroDec 2017View details →
dryad32/100

Botulinum toxin in the treatment of partially accommodative esotropia with high AC/A ratio

<p class="MsoNormal"><a name="OLE_LINK3"></a><a name="OLE_LINK6"></a><a name="OLE_LINK5"><span><span><b><span>Purpose:</span></b></span></span></a><span><span><span><span> To study the outcome of botulinum toxin (BTX) treatment (group 1) in partially accommodative esotropia with high accommodative convergence/accommodation (AC/A) ratio, in comparison with bilateral medial rectus muscles recessions and posterior fixation (group 2).</span></span></span></span></p><p></p><p></p> <p class="MsoNormal"><span><span><span><b><span>Methods:</span></b></span></span></span><span><span><span><span> In a retrospective comparative study, children aged 3-8 years old treated between 2011 and 2016, with partially accommodative esotropia with high AC/A ratio, deviation at distance of 10 prism diopters or more, and at least 1 year of follow-up, were included. Visual acuity, alternate prism and cover test, stereoacuity, biomicroscopy, and cycloplegic retinoscopy were carried out at initial, baseline visit, 6 months and 1 year after BTX injection or surgery. Main outcome variables were deviation at distance and near, improvement in stereoacuity, and percentage of success. We used multiple regression or proportional odds analysis to control for potential confounding variables.</span></span></span></span></p><p></p><p></p> <p class="MsoNormal"><span><span><span><b><span>Results:</span></b></span></span></span><span><span><span><span> Of 95 patients, 84 were eligible, 48 children in group 1 and 36 in group 2. Deviation and stereoacuity were similar in the two groups at 6 months, but significantly better in the BTX group at 1 year (median distance deviation 0 prism diopters vs 5 prism diopters, p&lt;0.01), although differences were not clinically relevant. Percentage of success was also significantly better only at 1 year (93% vs 72%, p=0.01). Change in distance-near disparity was not significantly different in the two groups in the period of study.</span></span></span></span></p><p></p><p></p> <p></p> <p class="MsoNormal"><span><span><span><b><span>Conclusions:</span></b></span></span></span><span><span><span><span> Botulinum toxin could be superior to, or as effective as surgery, at middle term, in the treatment of partially accommodative esotropia with high AC/A ratio. </span></span></span></span><span><span></span></span></p><p></p><p></p>

opencc-zeroFeb 2020View details →
dryad32/100

Data from: Photosynthetic pathways in Bromeliaceae: phylogenetic and ecological significance of CAM and C3 based on carbon isotope ratios for 1893 species

A comprehensive analysis of photosynthetic pathways in relation to phylogeny and elevational distribution was conducted in Bromeliaceae, an ecologically diverse Neotropical family containing large numbers of both terrestrial and epiphytic species. Tissue carbon isotope ratio (δ13C) was used to determine the occurrence of crassulacean acid metabolism (CAM) and C3 photosynthesis in 1893 species, representing 57% of species and all 56 genera in the family. The frequency of δ13C values showed a strongly bimodal distribution: 1074 species (57%) had values more negative than −20‰ (mode = −26.7‰), typical of predominantly daytime carbon fixation via the C3 pathway, whereas 819 species (43%) possessed values less negative than −20‰ (mode = −13.3‰), indicative of predominantly nocturnal fixation of carbon via the CAM pathway. Amongst the six almost exclusively terrestrial subfamilies in Bromeliaceae, Brocchinioideae, Lindmanioideae and Navioideae consisted entirely of C3 species, with CAM species being restricted to Hechtioideae (all species of Hechtia tested), Pitcairnioideae (all species belonging to a xeric clade comprising Deuterocohnia, Dyckia and Encholirium) and Puyoideae (21% of Puya spp.). Of the other two subfamilies, in the overwhelmingly epiphytic (plus lithophytic) Tillandsioideae, 28% of species possessed CAM photosynthesis, all restricted to the derived genus Tillandsia and tending towards the more extreme epiphytic 'atmospheric' life-form. In Bromelioideae, with comparable numbers of terrestrial and epiphytic species, 90% of taxa showed CAM; included in these are the first records of CAM photosynthesis in Androlepis, Canistropsis, Deinacanthon, Disteganthus, Edmundoa, Eduandrea, Hohenbergiopsis, Lymania, Pseudananas, Ronnbergia and Ursulaea. With respect to elevational gradients, the greatest number of C3 bromeliad species were found at mid-elevations between 500 and 1500 m, whereas the frequency of CAM species declined monotonically with increasing elevation. However, in Puya, at least ten CAM species have been recorded at elevations &gt; 3000 m, showing that CAM photosynthesis is not necessarily incompatible with low temperatures. This survey identifies five major origins of CAM photosynthesis at a higher taxonomic level in Bromeliaceae, but future phylogenetic work is likely to reveal a more fine-scale pattern of gains and losses of this trait, especially in ecologically diverse and widely distributed genera such as Tillandsia and Puya

opencc-zeroDec 2014View details →
dryad32/100

Data from: Testing sex ratio theory with the malaria parasite Plasmodium mexicanum in natural and experimental infections

The malaria parasite (Plasmodium) life history accords well with the assumptions of Local Mate Competition (LMC) of sex ratio theory. Within a single meal of the blood-feeding vector, sexually dimorphic gametocyte cells produce gametes (females produce 1, males several) that mate and undergo sexual recombination. The theory posits several factors drive the Plasmodium sex ratio: male fecundity (gametes/ male gametocyte), number and relative abundance of parasite clones, and gametocyte density. We measured these traits for the lizard malaria parasite, P. mexicanum, with a large sample of natural infections and infections from experiments which manipulated clonal diversity. Sex ratio in single-clone infections was slightly female-biased, but matched predictions of theory for this low-fecundity species. Sex ratio was less female-biased in clonally diverse infections as predicted by LMC for the experimental, but not natural infections. Gametocyte density was not positively related to sex ratio. These results are explained by the P. mexicanum life history of naturally low clonal diversity and high gametocyte production. This is the first study of a natural malaria system that examines all traits relevant to LMC in individual vertebrate hosts and suggests a striking example of sex ratio theory having significance for human public health.

opencc-zeroDec 2012View details →
dryad32/100

Data from: Variation in age ratio of midcontinent greater white-fronted geese during fall migration

Annual productivity is an important parameter for the management of waterfowl populations. Fall age ratio (juveniles:total birds) is an index of productivity of the preceding breeding season. However, differences in the timing of migration between family groups and nonbreeding birds may bias age-ratio estimates. We examined temporal variation in age ratios of midcontinent greater white-fronted geese Anser albifrons frontalis from interior and northwestern Alaska at a northern autumn staging area near Delta Junction, Alaska. Photographic sampling conducted near Delta Junction resulted in an annual age ratio of 0.388 ± 0.004 (mean ± SE) in 2010 and 0.390 ± 0.001 in 2011. Our study demonstrated temporal variation in age ratios over the duration of the migration period during August and September. We recommend that sampling be conducted for 3-d periods at the beginning, middle, and end of the migration period to account for temporal variation in migration of family groups.

opencc-zeroDec 2017View details →
dryad32/100

Mass ratio effects underlie ecosystem responses to environmental change

1. Random species loss has been shown experimentally to reduce ecosystem function, sometimes more than other anthropogenic environmental changes. Yet, controversy surrounds the importance of this finding for natural systems where species loss is non-random. 2. We compiled data from 16 multi-year experiments located at a single site in native tallgrass prairie. These experiments included responses to 11 anthropogenic environmental changes, as well as non-random biodiversity loss - either the removal of uncommon/rare plant species or the most common (dominant) species. 3. As predicted by the mass ratio hypothesis, loss of a dominant species had large impacts on productivity that were comparable to other anthropogenic drivers. In contrast, the loss of uncommon/rare species had small effects on productivity despite having the largest effects on species richness. 4. The anthropogenic drivers that had the largest effects on productivity – nitrogen, irrigation, and fire – experienced not only loss of species but also significant changes in the abundance and identity of dominant species. 5. Synthesis. These results suggest that mass ratio effects rather than species loss per se is an important determinant of ecosystem function with environmental change.

opencc-zeroNov 2019View details →
dryad32/100

Data from: Detecting elusive aspects of wildlife ecology using drones: new insights on the mating dynamics and operational sex ratios of sea turtles

Offspring and breeding (operational) sex ratios (OSR) are a key component of demographic studies. While offspring sex ratios are often relatively easy to measure, measuring OSRs is often far more problematic. Yet highly skewed OSRs, and a lack of male-female encounters, may be an important extinction driver. Using loggerhead sea turtles (Caretta caretta) as a case study, we showed the utility of drones, i.e. unmanned aerial vehicles (UAVs) to distinguish adult males and females in a marine breeding area, using a combination of morphological characteristics (tail length) and behavioural differences (active mating, courting and searching by males versus resting by females). Through repeated surveys, we documented seasonal changes in the OSR. While the number, and ratio, of males and females on the breeding grounds changed massively, the ratio of receptive females (derived from the rate of influx of new individuals to the area) to breeding males remained close to 1:1 for much of the period before nesting commenced. Hence, we show how large imbalances in the number of adult males and females may translate into relatively balanced OSRs. Our results suggest that the departure of males from the breeding grounds is linked to a decline in female receptivity, with female sea turtles being known to store sperm to ensure high clutch fertility throughout the nesting season. In conclusion, while we detected up to three times more females than males at the breeding ground, at present, OSRs appear stable. However, because most males breed annually (versus biannually by females), there might only be ˜100 males in the adult population (i.e. adult sex ratio of 1:7.5), which might become further skewed under expected climate change scenarios; thus, we need to identify the minimum number of males required to prevent extinction. Finally, we highlight the use of UAVs for assessing the mating dynamics of other marine, terrestrial or avian species, in which adults might exhibit visually detectable differences, such as sexual dimorphism, external body characteristics or grouping tendencies.

opencc-zeroDec 2016View details →
dryad32/100

Data from: Queen-worker ratio affects reproductive skew in a socially polymorphic ant

The partitioning of reproduction among individuals in communally breeding animals varies greatly among species, from the monopolization of reproduction (high reproductive skew) to similar contribution to the offspring in others (low skew). Reproductive skew models explain how relatedness or ecological constraints affect the magnitude of reproductive skew. They typically assume that individuals are capable of flexibly reacting to social and environmental changes. Most models predict a decrease of skew when benefits of staying in the group are reduced. In the ant Leptothorax acervorum, queens in colonies from marginal habitats form dominance hierarchies and only the top-ranking queen lays eggs ("functional monogyny"). In contrast, queens in colonies from extended coniferous forests throughout the Palaearctic rarely interact aggressively and all lay eggs ("polygyny"). An experimental increase of queen:worker ratios in colonies from low-skew populations elicits queen–queen aggression similar to that in functionally monogynous populations. Here, we show that this manipulation also results in increased reproductive inequalities among queens. Queens from natural overwintering colonies differed in the number of developing oocytes in their ovaries. These differences were greatly augmented in queens from colonies with increased queen:worker ratios relative to colonies with a low queen:worker ratio. As assumed by models of reproductive skew, L. acervorum colonies thus appear to be capable of flexibly adjusting reproductive skew to social conditions, yet in the opposite way than predicted by most models.

opencc-zeroDec 2014View details →
dryad32/100

Data from: Positive selection of deleterious alleles through interaction with a sex-ratio suppressor gene in African buffalo: a plausible new mechanism for a high frequency anomaly

Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer) population of Kruger National Park, through positive selection of these alleles that is ultimately driven by a sex-ratio suppressor. We have previously shown that one in four Kruger buffalo has a Y-chromosome profile that, despite being associated with low body condition, appears to impart a relative reproductive advantage, and which is stably maintained through a sex-ratio suppressor. Apparently, this sex-ratio suppressor prevents fertility reduction that generally accompanies sex-ratio distortion. We hypothesize that this body-condition-associated reproductive advantage increases the fitness of alleles that negatively affect male body condition, causing genome-wide positive selection of these alleles. To investigate this we genotyped 459 buffalo using 17 autosomal microsatellites. By correlating heterozygosity with body condition (heterozygosity-fitness correlations), we found that most microsatellites were associated with one of two gene types: one with elevated frequencies of deleterious alleles that have a negative effect on body condition, irrespective of sex; the other with elevated frequencies of sexually antagonistic alleles that are negative for male body condition but positive for female body condition. Positive selection and a direct association with a Y-chromosomal sex-ratio suppressor are indicated, respectively, by allele clines and by relatively high numbers of homozygous deleterious alleles among sex-ratio suppressor carriers. This study, which employs novel statistical techniques to analyse heterozygosity-fitness correlations, is the first to demonstrate the abundance of sexually-antagonistic genes in a natural mammal population. It also has important implications for our understanding not only of the evolutionary and ecological dynamics of sex-ratio distorters and suppressors, but also of the functioning of deleterious and sexually-antagonistic alleles, and their impact on population viability.

opencc-zeroDec 2013View details →
dryad32/100

Data from: Is biasing offspring sex ratio adaptive? a test of Fisher's principle across multiple generations of a wild mammal in a fluctuating environment

Fisher's principle explains that population sex ratio in sexually reproducing organisms is maintained at 1:1 due to negative frequency-dependent selection, such that individuals of the rare sex realize greater reproductive opportunity than individuals of the more common sex until equilibrium is reached. If biasing offspring sex ratio towards the rare sex is adaptive, individuals that do so should have a higher number of grandoffspring. In a wild population of North American red squirrels (Tamiasciurus hudsonicus) that experiences fluctuations in resource abundance and population density, we show that overall across 26 years, the secondary sex ratio was 1:1; however, stretches of years during which adult sex ratio was biased did not yield offspring sex ratios biased towards the rare sex. Females that had litters biased towards the rare sex did not have more grandoffspring. Critically, adult sex ratio was not temporally autocorrelated across years, thus the population sex ratio experienced by parents was independent of the population sex ratio experienced by their offspring by the time of their primiparity. Expected fitness benefits of biasing offspring sex ratio may be masked or negated by fluctuating environments across years, which limit the predictive value of the current sex ratio.

opencc-zeroDec 2017View details →
dryad32/100

Comparing the strength of modular signal, and evaluating alternative modular hypotheses, using covariance ratio effect sizes with morphometric data

<p>The study of modularity is paramount for understanding trends of phenotypic evolution, and for determining the extent to which covariation patterns are conserved across taxa and levels of biological organization. However, biologists currently lack quantitative methods for statistically comparing the strength of modular signal across datasets, and a robust approach for evaluating alternative modular hypotheses for the same dataset. As a solution to these challenges, we propose an effect size measure (Z_CR) derived from the covariance ratio, and develop hypothesis-testing procedures for their comparison. Computer simulations demonstrate that Z_CR displays appropriate statistical properties and low levels of misspecification, implying that it correctly identifies modular signal, when present. By contrast, alternative methods based on likelihood (EMMLi) and goodness of fit (MINT) suffer from high false positive rates and high model misspecification rates. An empirical example in sigmodontine rodent mandibles is provided to illustrate the utility of Z_CR for comparing modular hypotheses. Overall, we find that covariance ratio effect sizes are useful for comparing patterns of modular signal across datasets or for evaluating alternative modular hypotheses for the same dataset. Finally, the statistical philosophy for pairwise model comparisons using effect sizes should accommodate any future analytical developments for characterizing modular signal.</p>

opencc-zeroNov 2019View details →
dryad32/100

Data from: Predation drives stable coexistence ratios between red and green pea aphid morphs

We conducted field surveys and experiments to evaluate the hypothesis that predation is an important driving factor determining the degree of coexistence between red and green morphs of the pea aphid Acyrthosiphon pisum. Theory suggests that the different colour morphs are differentially susceptible to natural enemies and selection by predation which in turn leads to variable relative abundances of red and green morphs among host plants across landscapes. Our field surveys on pea and alfalfa revealed, however, that the colour morphs tended to coexist closely in a ratio of one red to three green aphids across fields with different host plant monocultures. Experimentation involving manipulation of the relative abundances of the two colour morphs on host plants pea and alfalfa with and without predator presence revealed that red morphs had higher or same fitness (per capita reproduction) than green morphs on both pea and alfalfa only when in the proportion of one red/three green proportion. Moreover, experimentation evaluating predator efficiency revealed that red morphs are safest from predation when in a 1 : 3 ratio with green morphs. These results suggest that in addition to predation selection effects, red morphs may behaviourally choose to associate with green morphs in a narrow 1 : 3 ratio to maximize their fitness. This evidence, along with existing published data on red and green morph anti-predator behaviour indicates that a 1 : 3 red and green morph coexistence ratio is driven by a balance between predation pressure and behavioural assorting by red morphs across landscapes. In this way predators may have ecological-evolutionary consequences for traits that affect the colour morphs' proportion and tolerances to selective pressure.

opencc-zeroDec 2011View details →
zenodo32/100

Observations of molecular hydrogen (H2) mixing ratio and stable isotopic composition (deuterium content) at the Cabauw tall tower in the Netherlands

<p>This zip file contains the final corrected data that were used for the journal article "Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands" by Batenburg et al., Atmospheric Environment, 2016, doi:10.1016/j.atmosenv.2016.09.058<br>  <br> Please cite the original AtmosEnv article when using these data.<br> The paper also contains more information about how these data were collected and calibrated, and on how the quality control flags were assigned.</p> <p>All samples were collected at the Cabauw tower, at the CESAR site (51.971° N, 4.927° E, http://www.cesar-observatory.nl/).<br> H2 and deltaD(H2) are calibrated using one to four laboratory reference air cylinders, depending on measurement period.<br> The H2 mixing ratio of the reference cylinders was determined by UHEI-IUP, MPI-BGC, or the IMAU isotope laboratory.<br> The deltaD(H2) of the reference cylinders is, sometimes indirectly,  linked to the VSMOW scale by measurements of air mixtures containing H2 standards of known isotopic composition.<br> H2 scale: MPI2009, Jordan and Steinberg, AMT, 2011, doi:10.5194/amt-4-509-2011<br> deltaD(H2) units: permil deviation from VSMOW, Gonfiantini et al., IAEA-TECDOC-825, IAEA</p> <p>Times are UTC. </p> <p><br> The corresponding author can be reached through annekebatenburg@gmail.com for questions.</p>

opencc-by-4.0Sep 2016View details →
zenodo32/100

Scaling of the plasma density on the expansion ratio

<p>Scaling of the plasma density on the expansion ratio</p>

opencc-by-4.0Dec 2016View details →
zenodo32/100

FIGURE 6. Ratio diagram comparing the mean logarithm values for each external and cranial dimension among Phyllotis a. andium, P. a in Taxonomic revision of the Andean leaf-eared mouse, Phyllotis andium Thomas 1912 (Rodentia: Cricetidae), with the description of a new species

FIGURE 6. Ratio diagram comparing the mean logarithm values for each external and cranial dimension among Phyllotis a. andium, P. a.stenops and Phyllotis occidens sp. nov. See Materials and methods for abbreviations.

opennotspecifiedDec 2015View details →

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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.

allen-brain-atlas
neuroscienceopenDocumentation, web resources, and API references are available online.
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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.

abode-home-cage
behavioral-neuroscienceopenThe DataShare record exposes download links for annotations, documentation, license text, and the zipped per-snippet data directory.
Last verified 2026-04-30Open record

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DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.

dandi-nwb
electrophysiologyopenPublished Dandiset metadata and archive endpoints are available through the production DANDI API.
Last verified 2026-04-30Open record

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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.

ibl
behavioral-neuroscienceopenPublic sessions can be searched and loaded from the IBL public data server through ONE.
Last verified 2026-04-29Open record

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Last verified 2026-04-29Open record

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