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13,017 results for “Positionning”
Data from: Boldness predicts an individual's position along an exploration-exploitation foraging trade-off
Individuals do not have complete information about the environment and therefore they face a trade-off between gathering information (exploration) and gathering resources (exploitation). Studies have shown individual differences in components of this trade-off but how stable these strategies are in a population and the intrinsic drivers of these differences is not well understood. Top marine predators are expected to experience a particularly strong trade-off as many species have large foraging ranges and their prey often have a patchy distribution. This environment leads these species to exhibit pronounced exploration and exploitation phases but differences between individuals are poorly resolved. Personality differences are known to be important in foraging behaviour but also in the trade-off between exploration and exploitation. Here we test whether personality predicts an individual exploration-exploitation strategy using wide ranging wandering albatrosses (Diomedea exulans) as a model system. Using GPS tracking data from 276 wandering albatrosses, we extract foraging parameters indicative of exploration (searching) and exploitation (foraging) and show that foraging effort, time in patch and size of patch are strongly correlated, demonstrating these are indicative of an exploration-exploitation strategy. Furthermore, we show these are consistent within individuals and appear stable in the population, with no reproductive advantage. The searching and foraging behaviour of bolder birds placed them towards the exploration end of the trade-off, whereas shy birds showed greater exploitation. This result provides a mechanism through which individual foraging strategies may emerge. Age and sex affected components of the trade-off, but not the trade-off itself, suggesting these factors may drive behavioural compensation to maintain resource acquisition and this was supported by the evidence that there were no fitness consequence of any EE trait nor the trade-off itself. These results demonstrate a clear trade-off between information gathering and exploitation of prey patches, and reveals for the first time that boldness may drive these differences. This provides a mechanism through which widely reported links between personality and foraging may emerge.
Data from: Preference for outbred host plants and positive effects of inbreeding on egg survival in a specialist herbivore
Inbreeding can profoundly affect the interactions of plants with herbivores as well as with the natural enemies of the herbivores. We studied how plant inbreeding affects herbivore oviposition preference, and whether inbreeding of both plants and herbivores alters the probability of predation or parasitism of herbivore eggs. In a laboratory preference test with the specialist herbivore moth Abrostola asclepiadis and inbred and outbred Vincetoxicum hirundinaria plants, we discovered that herbivores preferred to oviposit on outbred plants. A field experiment with inbred and outbred plants that bore inbred or outbred herbivore eggs revealed that the eggs of the outbred herbivores were more likely to be lost by predation, parasitism or plant hypersensitive responses than inbred eggs. This difference did not lead to differences in the realized fecundity as the number of hatched larvae did not differ between inbred and outbred herbivores. Thus, the strength of inbreeding depression in herbivores decreases when their natural enemies are involved. Plant inbreeding did not alter the attraction of natural enemies of the eggs. We conclude that inbreeding can significantly alter the interactions of plants and herbivores at different life-history stages, and that some of these alterations are mediated by the natural enemies of the herbivores.
Data from: The influence of the fetal leg position on the outcome in vaginally intended deliveries out of breech presentation at term – a FRABAT prospective cohort study
<p>Introduction: Vaginal delivery out of a breech presentation in pregnancies at term are being re-implemented into clinical practice. Still, recommendations regarding exclusion criteria leading to caesarean sections are based on expert opinions, not on evidence based guidelines. The difference in perinatal outcome and course of delivery in births with babies in frank breech position and babies in incomplete or complete breech presentation never has been investigated in a large patient cohort.</p> <p>Objective: To compare perinatal outcome of vaginally intended breech deliveries between births out of frank breech position and incomplete/complete breech<br> presentation. Design: Prospective cohort study Sample: 884 women at term with a singleton in frank breech presentation (FB) and 284 women with incomplete or complete breech presentation (CB) intending vaginal birth between January 2004 and December 2018</p> <p>Methods: Maternal and fetal outcome was compared between groups using Pearson's Chi Square test. Birth duration parameters were analysed using logistic regression. Results: There were no differences in cesarean section rates (FB: 25.1%, CB 22.2%, p=0.317). Short-term fetal morbidity did not differ between groups (FB: 2.5%, CB: 2.8%, p=0.761). In vaginal deliveries the necessity to perform manual assistance was significantly more frequent in deliveries of infants in CB (FB: 39.9%, CB: 51.6%, p= 0.0013). Cord loops (FB: 10.1%, CB: 18.0%, p=0.0004) and cesarean sections necessary because of cord prolapses (FB: 1.4%, CB 8.1%, p=0.005) were significantly more often in deliveries with babies in CB.</p> <p>Conclusion: This study provides evidence, that perinatal morbidity is not associated with the fetal leg posture in vaginally intended breech deliveries. The higher risk for the need of manual assistance during vaginal birth in deliveries of babies out of complete or incomplete breech presentation suggests that obstetrical departments reimplementing the vaginal breech in their repertoire might start with births of babies out of frank breech presentation.</p>
Data from: No evidence of positive assortative mating for genetic quality in fruit flies
In sexual populations the effectiveness of selection will depend on how gametes combine with respect to genetic quality. If gametes with deleterious alleles are likely to combine with one another, deleterious genetic variation can be more easily purged by selection. Assortative mating, where there is a positive correlation between parents in a phenotype of interest such as body size, is often observed in nature, but does not necessarily reveal how gametes ultimately combine with respect to genetic quality itself. We manipulated genetic quality in fruit fly populations using an inbreeding scheme designed to provide an unbiased measure of mating patterns. While inbred flies had substantially reduced reproductive success, their gametes did not combine with those of other inbred flies more often than expected by chance, indicating a lack of positive assortative mating. Instead, we detected a negative correlation in genetic quality between parents, i.e., disassortative mating, which diminished with age. This pattern is expected to reduce the genetic variance for fitness, diminishing the effectiveness of selection. We discuss how mechanisms of sexual selection could produce a pattern of disassortative mating. Our study highlights that sexual selection has the potential to either increase or decrease genetic load.
Data from: A superlinear iteration method for calculation of finite length journal bearing's static equilibrium position
Solving the static equilibrium position is one of the most important parts of dynamic coefficients calculation and further coupled calculation of rotor system. The main contribution of this study is testing the superlinear iteration convergence method - twofold secant method, for determination of the static equilibrium position of journal bearing with finite length. Essentially, the Reynolds equation for stable motion is solved by finite difference method and the inner pressure is obtained by successive over-relaxation iterative method reinforced by the compound Simpson quadrature formula. The accuracy and efficiency of the twofold secant method are higher in comparison with the secant method and dichotomy. The total number of iterative steps required for the twofold secant method are about one-third of secant method and less than one-eighth of dichotomy for the same equilibrium position. The calculations for equilibrium position and pressure distribution for different bearing length, clearance and rotating speed were done. In the results, the eccentricity presents linear inverse proportional relationship to the attitude angle. The influence of the bearing length, clearance and bearing radius on the load-carrying capacity were also investigated. The results illustrate that larger bearing length, larger radius and smaller clearance are good for the load-carrying capacity of journal bearing. The application of twofold secant method can greatly reduce the computational time for calculation of the dynamic coefficients and dynamic characteristics of rotor-bearing system with a journal bearing of finite length.
Data from: Positive selection drives faster-Z evolution in silkmoths
Genes linked to X or Z chromosomes, which are hemizygous in the heterogametic sex, are predicted to evolve at different rates than those on autosomes. This "faster-X effect" can arise either as a consequence of hemizygosity, which leads to more efficient selection for recessive beneficial mutations in the heterogametic sex, or as a consequence of reduced effective population size of the hemizygous chromosome, which leads to increased fixation of weakly deleterious mutations due to genetic drift. Empirical results to date suggest that, while the overall pattern across taxa is complicated, systems with male-heterogamy show a faster-X effect attributable to more efficient selection, while the faster-Z effect in female-heterogametic taxa is attributable to increased drift. To test the generality of the faster-Z pattern seen in birds and snakes, we sequenced the genome of the Lepidopteran silkmoth Bombyx huttoni. We show that silkmoths experience faster-Z evolution, but unlike in birds and snakes, the faster-Z effect appears to be attributable to more efficient positive selection. These results suggest that female-heterogamy alone is unlikely to explain the reduced efficacy of selection on the bird Z chromosome. It is likely that many factors, including differences in overall effective population size, influence Z chromosome evolution.
Data from: Phylogeny of Leavenworthia S-alleles suggests unidirectional mating system evoution and enhanced positive selection following an ancient population bottleneck
The adoption of self-fertilization from an ancestral outcrossing state is one of the most common evolutionary transitions in the flowering plants. In the mustard family, outcrossing is typically enforced by sporophytic self-incompatibility (SI), but there are also many self-compatible species. The genus Leavenworthia contains taxa that either possess or lack SI. Here we present data showing that SI is associated with strict outcrossing and that there is widespread trans-specific sequence polymorphism at the locus involved in the recognition of self-pollen (the S-locus). This ancestral polymorphism is consistent with the presence of an outcrossing mating system in the common ancestor of Leavenworthia species, and suggests that there have been several independent losses of SI in the group. When compared with other mustard species, the bulk of Leavenworthia S-allele sequences are highly diverged from those found in other Brassicaceae and show relatively low levels of nucleotide diversity, a pattern that suggests the common ancestor of the genus likely underwent a strong population bottleneck. The hypothesis of post-bottleneck S-locus rediversification is supported by tests showing stronger positive selection acting on S-alleles from Leavenworthia than those found in other Brassicaceae.
Data from: Finding candidate genes under positive selection in non-model species: examples of genes involved in host specialization in pathogens
Numerous genes in diverse organisms have been shown to be under positive selection, especially genes involved in reproduction, adaptation to contrasting environments, hybrid inviability, and host-pathogen interactions. Looking for genes under positive selection in pathogens has been a priority in efforts to investigate coevolution dynamics and to develop vaccines or drugs. To elucidate the functions involved in host specialization, here we aimed at identifying candidate sequences that could have evolved under positive selection among closely related pathogens specialized on different hosts. For this goal, we sequenced ca. 17,000-32,000 ESTs from each of four Microbotryum species, which are fungal pathogens responsible for anther smut disease on host plants in the Caryophyllaceae. Forty-two of the 372 predicted orthologous genes showed significant signal of positive selection, which represents a good number of candidate genes for further investigation. Sequencing 16 of these genes in 9 additional Microbotryum species confirmed that they have indeed been rapidly evolving in the pathogen species specialized on different hosts. The genes showing significant signals of positive selection were putatively involved in nutrient uptake from the host, secondary metabolite synthesis and secretion, respiration under stressful conditions and stress response, hyphal growth and differentiation, and regulation of expression by other genes. Many of these genes had transmembrane domains and may therefore also be involved in pathogen recognition by the host. Our approach thus revealed fruitful and should be feasible for many non-model organisms for which candidate genes for diversifying selection are needed.
Data from: TAK-071, a muscarinic M1 receptor positive allosteric modulator, attenuates scopolamine-induced quantitative electroencephalogram power spectral changes in cynomolgus monkeys
Activation of the muscarinic M1 receptor is a promising approach to improve cognitive deficits associated with cholinergic dysfunction in Alzheimer's disease, dementia with Lewy bodies, and schizophrenia. TAK-071 is an M1-selective positive allosteric modulator that improves cognitive deficits induced by scopolamine, a non-selective muscarinic receptor antagonist, with reduced side effects on gastrointestinal function in rats. In this study, we explored changes in quantitative electroencephalography (qEEG) power bands, with or without scopolamine challenge, as a non-invasive translational biomarker for the effect of TAK-071 in cynomolgus monkeys. Scopolamine has been reported to increase theta and delta power bands and decrease alpha power band in healthy volunteers. In line with the clinical observations, scopolamine (25‒100 μg/kg, subcutaneous administration [s.c.]) increased theta and delta power bands in cynomolgus monkeys in a dose-dependent manner, whereas it had the opposite effect on alpha power band. The effects of TAK-071 on scopolamine (25 μg/kg, s.c.)-induced qEEG spectral changes were examined using an acetylcholinesterase inhibitor donepezil and a muscarinic M1/M4 receptor agonist xanomeline as comparative cholinomimetics. TAK-071 (0.3‒3 mg/kg, oral administration [p.o.]), donepezil (3 mg/kg, p.o.), and xanomeline (1 mg/kg, s.c.) suppressed the scopolamine-induced increases in alpha, theta, and delta power bands. These results suggest that changes in specific qEEG power bands, in particular theta and delta power bands in the context of scopolamine challenge, could be used as translational biomarkers for the evaluation of TAK-071 in clinical studies.
Data from: Socially selected ornaments and fitness: signals of fighting ability in paper wasps are positively associated with survival, reproductive success, and rank
Many animals have ornaments that mediate choice and competition in social and sexual contexts. Individuals with elaborate sexual ornaments typically have higher fitness than those with less elaborate ornaments, but less is known about whether socially selected ornaments are associated with fitness. Here, we test the relationship between fitness and facial patterns that are a socially-selected signal of fighting ability in Polistes dominula wasps. We found wasps that signal higher fighting ability have larger nests, are more likely to survive harsh winters, and obtain higher dominance rank than wasps that signal lower fighting ability. In comparison, body weight was not associated with fitness. Larger wasps were dominant over smaller wasps, but showed no difference nest size or survival. Overall, the positive relationship between wasp facial patterns and fitness indicates that receivers can obtain diverse information about a signaler's phenotypic quality by paying attention to socially selected ornaments. Therefore, there are surprisingly strong parallels between the information conveyed by socially and sexually selected signals. Similar fitness relationships in social and sexually selected signals may be one reason it can be difficult to distinguish the role of social versus sexual selection in ornament evolution.
Data from: Effect of expanded variation in anther position on pollinator visitation to wild radish, Raphanus raphanistrum
Background and Aims: Plant-pollinator interactions shape the evolution of flowers. Floral attraction and reward traits have often been shown to affect pollinator behavior, but the possible effect of efficiency traits on visitation behavior has rarely been addressed. Here we tested for the effect of anther position, usually considered a trait that influences efficiency of pollen deposition on pollinators, on pollinator visitation rates and visit duration in flowers of wild radish, Raphanus raphanistrum. Methods: We used artificial selection lines from two experiments that expanded the naturally-occurring phenotypic variation in anther position. In one experiment, plant lines were selected to either increase or decrease anther exsertion. The other experiment decreased anther dimorphism, which resulted in increased short stamen exsertion. We hypothesized that increased exsertion will increase visitation of pollen foragers due to increased visual attraction. We also hypothesized that exsertion of anthers above the corolla would interfere with nectar foragers and increase time of visit per flower. Key Results: In the exsertion selection experiment, increased exsertion of both short and long stamens resulted in an increased number of fly visits per plant, and in the dimorphism experiment bee visits increased with increased short stamen exsertion. Duration of nectar feeders declined significantly with increasing long stamen exsertion, as opposed to the hypothesis. Conclusions and synthesis: Until now, anther position was considered an efficiency trait to enhance pollen uptake and deposition. We show that anther position in wild radish has an ecological significance also in attracting pollen foragers. This study suggests an additional adaptive role for anther position beyond efficiency, and highlights the multiple ecological functions of floral traits in plant-pollinator interactions.
Data from: Molecular phylogeny of unikonts: new insights into the position of apusomonads and ancyromonads and the internal relationships of Opisthokontsí
The eukaryotic supergroup known as the Opisthokonta includes animals (Metazoa), fungi, choanoflagellates, as well as some poorly-studied unicellular eukaryotes, such as the Nucleariidea, Fonticula alba, the Ichthyosporea, the Filasterea and Corallochytrium limacisporum. Whereas the evolutionary positions of the well-known opisthokont lineages are mostly resolved, the specific phylogenetic relationships among those neglected opisthokont lineages is unsettled. Moreover, it remains unclear whether Amoebozoa or Apusozoa are the sister group to opisthokonts. Aiming at elucidating the evolutionary tree of the opisthokonts, we have produced a dataset with a large sampling of both organisms and number of genes, including representatives from all known opisthokont lineages. Moreover, we have generated new molecular data from an additional ichthyosporean (Creolimax fragrantissima) and a choanoflagellate (Codosiga botrytis). Our analyses show the Apusozoa as a paraphyletic assemblage with the Apusomonadida as sister group to Opisthokonta. Within the the Holozoa, the Ichthyosporea are shown as the first splitting group, followed by C. limacisporum, the Filasterea, the Choanoflagellata, and the Metazoa. With this taxon-rich opisthokont tree, it is possible to pinpoint the origin and evolution of morphological characters. As an example, we discuss cilia evolution under the evolutionary scenario here presented.
Data from: Invasion-mediated effects on marine trophic interactions in a changing climate: positive feedbacks favour kelp persistence
The interactive effects of ocean warming and invasive species are complex and remain a source of uncertainty for projecting future ecological change. Climate-mediated change to trophic interactions can have pervasive ecological consequences, but the role of invasion in mediating trophic effects is largely unstudied. Using manipulative experiments in replicated outdoor mesocosms, we reveal how near-future ocean warming and macrophyte invasion scenarios interactively impact gastropod grazing intensity and preference for consumption of foundation macroalgae (Ecklonia radiata and Sargassum vestitum). Elevated water temperature increased consumption of both macroalgae through greater grazing intensity. Given the documented decline of kelp (E. radiata) growth at higher water temperatures, enhanced grazing could contribute to the shift from kelp-dominated to Sargasssum-dominated reefs that is occurring at the low-latitude margins of kelp distribution. However, presence of a native invader (Caulerpa filiformis) was related to low consumption by the herbivores on dominant kelp at warmer temperatures. Thus, antagonistic effects between climate change and a range expanding species can favour kelp persistence in a warmer future. Introduction of species should, therefore, not automatically be considered unfavourable under climate change scenarios. Climatic changes are increasing the need for effective management actions to address the interactive effects of multiple stressors and their ecological consequences, rather than single threats in isolation.
Data from: What's in an outgroup? The impact of outgroup choice on the phylogenetic position of Thalattosuchia (Crocodylomorpha) and the origin of Crocodyliformes
Outgroup sampling is a central issue in phylogenetic analysis. However, good justification is rarely given for outgroup selection in published analyses. Recent advances in our understanding of archosaur phylogeny suggest that many previous studies of crocodylomorph and crocodyliform relationships have rooted trees on outgroup taxa that are only very distantly related to the ingroup (e.g., Gracilisuchus stipanicicorum), or might actually belong within the ingroup. Thalattosuchia, a group of Mesozoic marine crocodylomorphs, has a controversial phylogenetic position—they are recovered as either the sister group to Crocodyliformes, in a basal position within Crocodyliformes, or nested high in the crocodyliform tree. Thalattosuchians lack several crocodyliform apomorphies, but share several character states with derived long-snouted forms with a similar ecological habit, suggesting their derived position may be the result of convergent evolution. Several of these "shared" characters may result from ambiguously worded character state definitions—structures that are superficially similar but anatomically different in detail are identically coded. A new analysis of crocodylomorphs with increased outgroup sampling recovers Thalattosuchia as the sister group to Crocodyliformes, distantly related to long-snouted crocodyliforms. I also demonstrate that expanding the outgroup sampling of previously published matrices results in the recovery of thalattosuchians as sister to Crocodyliformes. The exclusion of thalattosuchians from Crocodyliformes has numerous implications for large-scale evolutionary trends within the group, including extensive convergence in the evolution of the secondary palate characteristic of the group. These results demonstrate the importance of careful outgroup sampling and character construction, and their profound effect on the position of labile clades.
Data from: A novel method for estimating the strength of positive mating preference by similarity in the wild
Mating preference can be a driver of sexual selection and assortative mating and is, therefore, a key element in evolutionary dynamics. Positive mating preference by similarity is the tendency for the choosy individual to select a mate which possesses a similar variant of a trait. Such preference can be modelled using Gaussian-like mathematical functions that describe the strength of preference, but such functions cannot be applied to empirical data collected from the field. As a result, traditionally, mating preference is indirectly estimated by the degree of assortative mating (using Pearson's correlation coefficient, r) in wild captured mating pairs. Unfortunately, r and similar coefficients are often biased due to the fact that different variants of a given trait are nonrandomly distributed in the wild, and pooling of mating pairs from such heterogeneous samples may lead to "false–positive" results, termed "the scale-of-choice effect" (SCE). Here we provide two new estimators of mating preference (Crough and Cscaled) derived from Gaussian-like functions which can be applied to empirical data. Computer simulations demonstrated that r coefficient showed robust estimations properties of mating preference but it was severely affected by SCE, Crough showed reasonable estimation properties and it was little affected by SCE, while Cscaled showed the best properties at infinite sample sizes and it was not affected by SCE but failed at biological sample sizes. We recommend using Crough combined with the r coefficient to infer mating preference in future empirical studies.
Data from: Heterogeneity in local density allows a positive evolutionary relationship between self-fertilisation and dispersal
Despite empirical evidence for a positive relationship between dispersal and self-fertilisation (selfing), theoretical work predicts that these traits should always be negatively correlated, and the Good Coloniser Syndrome of high dispersal and selfing (Cf. Baker's Law) should not evolve. Critically, previous work assumes that adult density is spatiotemporally homogeneous, so selfing results in identical offspring production for all patches, eliminating the benefit of dispersal for escaping from local resource competition. We investigate the joint evolution of dispersal and selfing in a demographically structured metapopulation model where local density is spatiotemporally heterogeneous due to extinction-recolonisation dynamics. Selfing alleviates outcrossing failure due to low local density (an Allee Effect) while dispersal alleviates competition through dispersal of propagules from high- to low-density patches. Because local density is spatiotemporally heterogenous in our model, selfing does not eliminate heterogeneity in competition, so dispersal remains beneficial even under full selfing. Hence the Good Coloniser Syndrome is evolutionarily stable under a broad range of conditions, and both negative and positive relationships between dispersal and selfing are possible, depending on the environment. Our model thus accommodates positive empirical relationships between dispersal and selfing not predicted by previous theoretical work and provides additional explanations for negative relationships.
Data from: Positive selection inhibits gene mobilization and transfer in soil bacterial communities
Horizontal gene transfer (HGT) between bacterial lineages is a fundamental evolutionary process that accelerates adaptation. Sequence analyses show that conjugative plasmids are principal agents of HGT in natural communities. However, we lack understanding of how the ecology of bacterial communities and their environments affect the dynamics of plasmid-mediated gene mobilization and transfer. Here we show, in simple experimental soil bacterial communities containing a conjugative mercury resistance plasmid, the repeated, independent mobilization of transposon-borne genes from chromosome to plasmid, plasmid to chromosome and, in the absence of mercury selection, interspecific gene transfers from the chromosome of one species to the other via the plasmid. By reducing conjugation, positive selection for plasmid-encoded traits, like mercury resistance, can consequently inhibit HGT. Our results suggest that interspecific plasmid-mediated gene mobilization is most likely to occur in environments where plasmids are infectious, parasitic elements rather than those where plasmids are positively selected, beneficial elements.
Data from: Integrating viscoelastic mass spring dampers into position-based dynamics to simulate soft tissue deformation in real time
We propose a novel method to simulate soft tissue deformation for virtual surgery applications. The method considers the mechanical properties of soft tissue, such as its viscoelasticity, nonlinearity, and incompressibility; its speed, stability, and accuracy also meet the requirements for a surgery simulator. Modifying the traditional equation for mass spring dampers introduces nonlinearity and viscoelasticity into the calculation of elastic force. Then, the elastic force is used in the constraint projection step for naturally reducing constraint potential. The node position is enforced by the combined spring force and constraint conservative force through Newton's second law. We conduct a comparison study of conventional mass spring dampers and position based dynamics (PBD) for our new integrating method. Our approach enables stable, fast, and large step simulation by freely controlling visual effects based on nonlinearity, viscoelasticity and incompressibility. We implement a laparoscopic cholecystectomy simulator to demonstrate the practicality of our method, in which liver and gallbladder deformation can be simulated in real time. Our method is an appropriate choice for the development of real-time virtual surgery applications.
Data from: An exceptionally high nucleotide and haplotype diversity and a signature of positive selection for the eIF4E resistance gene in barley are revealed by allele mining and phylogenetic analyses of natural populations.
In barley, the eukaryotic translation initiation factor 4E (eIF4E) gene situated on chromosome 3H is recognised as an important source of resistance to the bymoviruses Barley yellow mosaic virus and Barley mild mosaic virus. In modern barley cultivars two recessive eIF4E alleles, rym4 and rym5, confer different isolate-specific resistances. In this study the sequence of eIF4E was analysed in 1090 barley landraces and non-current cultivars originating from 84 countries. An exceptionally high nucleotide diversity was evident in the coding sequence of eIF4E but not in either the adjacent MCT-1 gene or the sequence related eIF(iso)4E gene situated on chromosome 1H. Surprisingly, all nucleotide polymorphisms detected in the coding sequence of eIF4E resulted in amino acid changes. A total of 47 eIF4E haplotypes were identified and phylogenetic analysis using maximum likelihood provided evidence of strong positive selection acting on this barley gene. The majority of eIF4E haplotypes were found to be specific to distinct geographic regions. Furthermore, the eIF4E haplotype diversity (uh) was found to be considerably higher in East Asia, whereas SNP genotyping identified a comparatively low degree of genome-wide genetic diversity in 16 out of 17 tested accessions (each carrying a different eIF4E haplotype) from this same region. In addition, selection statistic calculations using coalescent simulations showed evidence of non neutral variation for eIF4E in several geographic regions, including East Asia, the region with a long history of the bymovirus-induced yellow mosaic disease. Together these findings suggest eIF4E may play a role in barley adaptation to local habitats.
Data from: Molecular phylogenetics and biogeography of galaxiid fishes (Osteichthyes: Galaxiidae): dispersal, vicariance, and the position of Lepidogalaxias salamandroides
The galaxiid fishes exhibit a gondwanan distribution. We use mitochondrial DNA sequences to test conflicting vicariant and dispersal biogeographic hypotheses regarding the southern hemisphere range of this freshwater group. Although phylogenetic resolution of cytochrome b and 16S rRNA sequences is largely limited to more recent divergences, our data indicate that the radiation can be interpreted as a number of relatively recent dispersal events superimposed on an ancient gondwanan radiation. Genetic relationships contradict the findings of recent morphological analyses of galaxioid fishes. In particular, a number of hypotheses regarding phylogenetic placement of the enigmatic Lepidogalaxias are examined. While most workers consider Lepidogalaxias to be an unusual scaled member of the southern hemisphere galaxioids, it has also been suggested that this species is related to the northern hemisphere esocoids. Our data strongly suggest that this species is not a galaxiid; the alternative hypothesised esocoid relationship cannot be rejected. The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships. Juvenile saltwater-tolerance is phylogenetically distributed throughout the Galaxiinae and the loss of this migratory phase may be a major cause of speciation.
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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.
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.
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