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2,395 results for “Contrast”
Data from: Invasion success in polyploids: the role of inbreeding in the contrasting colonization abilities of diploid versus tetraploid populations of Centaurea stoebe s.l
As a consequence of founder effects, inbreeding can hamper colonization success: First, in species with self-incompatibility controlled by an S-locus, inbreeding may decrease cross-compatibility, mainly due to the sharing of identical S-alleles between closely related mating partners. Secondly, inbreeding can reduce fitness of inbred relative to outbred offspring (i.e. inbreeding depression). Polyploids often show reduced inbreeding depression compared to diploids, which may contribute to the overrepresentation of polyploids among invasive species. This is the first study that tests how the effects of inbreeding differ between geocytotypes (i.e. ploidy levels within a given range). Our model organism, Centaurea stoebe, is strictly self-incompatible and comprises three geocytotypes: diploids are more frequent than tetraploids in the native range, while only tetraploids occur in the invasive range. We conducted a breeding experiment (sib-mating vs. outcrossing) with 14 native diploid, 13 native tetraploid and 15 invasive tetraploid populations. We recorded cross-compatibility and estimated a cumulative index for offspring fitness. Since frequent inbreeding can result in purging of genetic load responsible for inbreeding depression, our analyses included a metric for within-population relatedness, based on eight microsatellite markers, to assess the effect of purging. Inbreeding was found to reduce cross-compatibility, which was similarly pronounced in diploids and tetraploids. It also caused inbreeding depression in cumulative fitness, which was significant in diploids but not in tetraploids. No evidence of purging was observed as inbred fitness was not affected by within-population relatedness. Synthesis. Our results provide new insights into the contrasting invasion success of the cytotypes of C. stoebe. As the effects of cross-compatibility and purging were comparable between cytotypes, both processes can be ruled out to affect the colonization success of diploids versus tetraploids. Our findings are consistent with the hypothesis that polyploidy increases the masking of recessive mutations, which maintains high fitness in inbred tetraploids and may thus facilitate colonization of new ranges. We highlight that reduced inbreeding depression may add to previously acknowledged advantages of polyploids in range expansions, a mechanism that may hitherto have been underestimated due to a lack of data on variation in inbreeding depression across geocytotypes.
Data from: Clone configuration and spatial genetic structure of two Halophila ovalis populations with contrasting internode lengths
Fine-scale spatial genetic structure (SGS) is predominantly determined by gene flow. While sexually reproducing plants can disperse their genes through pollen and seed grains, clonal plants can additionally disperse genes through clonal growth. Plants' clonal reproduction strategy, however, often varies within and between species. Still, the effect of differential clonal reproduction strategy on fine-scale SGS remains somewhat unclear. Halophila ovalis is a fast-growing clonal seagrass, whose internode length (which defines a species' clonal reproduction strategy) varies among populations. Using eight polymorphic microsatellites, here we compare the genetic diversity, clonal structure and fine-scale SGS of two H. ovalis populations with contrasting internode lengths (Yingluo versus Xialongwei populations). We found moderate to high genotypic and allelic richness and heterozygosities in both populations. Compared to Xialongwei population, genetic and genotypic diversity was significantly lower in Yingluo population. Although their internode length was relatively short, clones of Yingluo population spread farther than those of Xialongwei population. Sexual-to-vegetative dispersal variance ratios were 34.6 and 445.5 in Yingluo and Xialongwei populations, respectively. In both populations, clonal growth significantly intensified the SGS, especially in short distance classes. The SGS at small distance classes were weaker in Yingluo than Xialongwei, in part, due to more intermingled distribution of genets and more extensive clonal expansion in the former population. Our results indicate that vegetative dispersal variance/distance, rather than internode length, plays a crucial role in shaping the fine-scale genetic structure.
Data from: Contrasting drivers of reproductive ageing in albatrosses
1.Age-related variation in reproductive performance is ubiquitous in wild vertebrate populations and has important consequences for population and evolutionary dynamics. 2.The ageing trajectory is shaped by both within-individual processes, such as improvement and senescence, and by the among-individual effects of selective appearance and disappearance. To date, few studies have compared the role of these different drivers among species or populations. 3.In this study, we use nearly 40 years of longitudinal monitoring data to contrast the within- and among-individual processes contributing to the reproductive ageing patterns in three albatross species (two biennial and one annual breeder), and test whether these can be explained by differences in life-histories. 4.Early life performance in all species increased with age, and was predominantly influenced by within-individual improvements. However, reproductive senescence was detected in only two of the species. In the species exhibiting senescent declines, we also detected a terminal improvement in breeding success. This is suggestive of a trade-off between reproduction and survival, which was supported by evidence of selective disappearance of good breeders. 5.We demonstrate that comparisons of closely-related species which differ in specific aspects of their life-history can shed light on the ecological and evolutionary forces shaping variation in ageing patterns.
Data from: Contrasting drivers of diversification rates on islands and continents across three Passerine families
Rates of diversification vary greatly among taxa. Understanding how species-specific traits influence speciation rates will help elucidate mechanisms driving the production and maintenance of biodiversity over broad spatiotemporal scales. Ecological specialization and range size are two characteristics thought to predict differences in speciation rates among clades, yet each mechanism predicts both increases and decreases in speciation. We estimate a continuous index of specialization using avian bill morphology. We determine the relative effect of specialization and range size and shape on speciation rates across 559 species within the Emberizoidea superfamily, a morphologically diverse clade distributed across the Americas and associated islands. We find a significant positive correlation between specialization and speciation rate, and a negative correlation with range size. Only the effect of specialization persisted after removing island endemics, suggesting that ecological specialization is an important driver of diversity across large macroevolutionary scales and the relative importance of specific drivers may differ on islands and continents.
Data from: Contrasting definitive hosts as determinants of the genetic structure in a parasite with complex life cycle along the Southeastern Pacific
The spatial genetic structure (and gene flow) of parasites with complex life cycles, such as digeneans, has been attributed mainly to the dispersion ability of the most mobile host, which most often corresponds to the definitive host (DH). In this study, we compared the genetic structure and diversity of adult Neolebouria georgenascimentoi in two fish species (DHs) that are extensively distributed along the Southeastern Pacific (SEP). The analysis was based on the cytochrome oxidase subunit I gene sequences of parasites collected between 23°S and 45°S. In total, 202 sequences of N. georgenascimentoi in Pinguipes chilensis isolated from 9 sites and 136 sequences of Prolatilus jugularis from 5 sites were analyzed. Our results showed that N. georgenascimentoi is a species complex that includes three different parasite species; however, in this study, only group 1 and 2 found in P. chilensis and P. jugularis, respectively, were studied because they are widely distributed along the coastline. Group 1 parasites had two common haplotypes with wide distribution and unique haplotypes in northern sites. Group 2 had only one common haplotype with wide distribution and a large number of unique haplotypes with greater genetic diversity. Both groups have experienced recent population expansion. Only group 1 exhibited a genetic structure that was mainly associated with a biogeographic break at approximately 30°S along the SEP. Our finding suggests that host access to different prey (=intermediate hosts) could affect the genetic structure of the parasite complex discovered here. Consequently, difference between these patterns suggests that factors other than DH dispersal are involved in the genetic structure of autogenic parasites.
Data from: Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes
Hypersaline meromictic lakes are extreme environments in which water stratification is associated with powerful physicochemical gradients and high salt concentrations. Furthermore, their physical stability coupled with vertical water column partitioning makes them important research model systems in microbial niche differentiation and biogeochemical cycling. Here, we compare the prokaryotic assemblages from Ursu and Fara Fund hypersaline meromictic lakes (Transylvanian Basin, Romania) in relation to their limnological factors and infer their role in elemental cycling by matching taxa to known taxon-specific biogeochemical functions. To assess the composition and structure of prokaryotic communities and the environmental factors that structure them, deep-coverage small subunit (SSU) ribosomal RNA (rDNA) amplicon sequencing, community domain-specific quantitative PCR and physicochemical analyses were performed on samples collected along depth profiles. The analyses showed that the lakes harbored multiple and diverse prokaryotic communities whose distribution mirrored the water stratification patterns. Ursu Lake was found to be dominated by Bacteria and to have a greater prokaryotic diversity than Fara Fund Lake that harbored an increased cell density and was populated mostly by Archaea within oxic strata. In spite of their contrasting diversity, the microbial populations indigenous to each lake pointed to similar physiological functions within carbon degradation and sulfate reduction. Furthermore, the taxonomy results coupled with methane detection and its stable C isotope composition indicated the presence of a yet-undescribed methanogenic group in the lakes' hypersaline monimolimnion. In addition, ultrasmall uncultivated archaeal lineages were detected in the chemocline of Fara Fund Lake, where the recently proposed Nanohaloarchaeota phylum was found to thrive.
FIGURES 14–18. Oribatella canadensis, interference contrast micrographs from slide preparations. 14 in The first sexually dimorphic species of Oribatella (Acari, Oribatida, Oribatellidae) and a review of sexual dimorphism in the Brachypylina
FIGURES 14–18. Oribatella canadensis, interference contrast micrographs from slide preparations. 14, adult female, rostrum, anterior at top; 15, custodium and seta 3c; 16, adult male, detail of porose region, with porose area A3 indicated by arrow; 17, adult female, interlamellar region; 18, food bolus, with arrow to hyphal fragment.
FIGURES 1–7 in Description of a new genus and two new species of Leiodidae (Coleoptera) from Baltic amber using phase contrast synchrotron X-ray microtomography
FIGURES 1–7. External and internal morphology of Catops perkovskyi sp. n. (holotype) by PPC-SRμCT. 1, habitus dorsal view. 2, habitus lateral view. 3, antenna. 4, front leg. 5, aedeagus, lateral view. 6, aedeagus, dorsal view. 7, apex of aedeagus, dorsal view.
FIGURES 8–17 in Description of a new genus and two new species of Leiodidae (Coleoptera) from Baltic amber using phase contrast synchrotron X-ray microtomography
FIGURES 8–17. External and internal morphology of Tafforeus cainosternus sp. n. (holotype) by PPC-SRμCT. 8, habitus dorsal view. 9, habitus lateral view. 10, prosternum and procoxal cavities from behind (pp = triangular prosternal process). 11, antenna. 12, protarsus, dorsal view. 13, mesotarsus, dorsal view. 14, posterior leg (th=ventral tooth). 15, mesoventral carina (msc) and mesocoxal cavity (mcx), lateral view. 16, aedeagus, lateral view. 17, aedeagus, dorsal view.
FIGURES 8–21 in A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography
FIGURES 8–21. CT reconstructions of Balticoroma wheateri new species (male holotype, GPIH). (8) frontal view showing chelicerae and labral spur; (9) view of right pedipalp showing embolus; (10–14) various views of right metatarsus 1, showing y-shaped clasping structure; (15) anterior view of specimen showing the section taken through the chelicerae to produce the raw data slice in Figure 16; (16) raw data slice demonstrating that the chelicerae and clypeal extentions are clearly separated; (20–21) various views of the right pedipalp. C, chelicera; ce, clypeal extension; co, dorsal cymbial outgrowth; cy, cymbium; e, embolus; eb, embolic base; ec, embolic coil;?fc, functional conductor sensu Wunderlich (2004); ls, labral spur; t, tegulum.
FIGURE 1 in A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography
FIGURE 1. Microphotograph of Balticoroma wheateri new species (male holotype, GPIH). Body length = 1.8 mm.
FIGURES 2–7 in A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography
FIGURES 2–7. CT reconstructions of Balticoroma wheateri new species (male holotype, GPIH). (2) right lateral view; (3) left lateral view; (4) dorsal view; (5) ventral view; (6) anterior view; (7) posterior view. Body length = 1.8 mm. Mt1, metatarsus 1; ta1, tarsus 1; ti1, tibia 1.
FIGURE 3 in Anopheles prachongae, a new species of the Gigas Complex of subgenus Anopheles (Diptera: Culicidae) in Thailand, contrasted with known forms of the complex
FIGURE 3. Fourth-instar larva of Anopheles prachongae. A, Head, dorsal (left) and ventral (right) aspects of left side. B, Thorax and abdominal segments I–VI, dorsal (left) and ventral (right) aspects of left side. C, Abdominal segments VII–X, left side. A, antenna; APP, anal papilla; C, cranium; P, prothorax; PP, pecten plate; Pt, pecten; M, mesothorax; MAPT, median accessory tergal plate; S, spiracular lobe; Sa, saddle; T, metathorax; TP, tergal plate; I–VIII,X = abdominal segments I–VIII and X; 1–15 = setal numbers for specified areas, e.g. seta 5-C.
FIGURE 2 in Anopheles prachongae, a new species of the Gigas Complex of subgenus Anopheles (Diptera: Culicidae) in Thailand, contrasted with known forms of the complex
FIGURE 2. (A‒C, E) Anopheles prachongae: A, pupa, left side of cephalothorax, dorsal to right; B, pupa, dorsal (left) and ventral (right) aspects of metathorax and abdomen; C, male genitalia, dorsal (tergal) aspect (note presence of two internal seta on left gonocoxite); E, apex of paddle. (D) Apex of paddle of An. baileyi. Ae, aedeagus; CL, claspette; CT, cephalothorax; Gc, gonocoxite; Gs, gonostylus; InS, internal seta; LAe, leaflets of aedeagus; Pa, paddle; PBS, parabasal setae; Ppr, paraproct; Pr, proctiger; RB, refractile border; I–IX = abdominal segments I–IX; 1–14 = setal numbers for specified areas, e.g. seta 3-I.
2D phase contrast HeLa cells images with ground truth annotations
<p>Original images are from http://www.robots.ox.ac.uk/~vgg/software/cell_detection/. This software is associated with the publication "Learning to Detect Cells Using Non-overlapping Extremal Regions", MICCAI 2012. (DOI: 10.1007/978-3-642-33415-3_43)</p> <p>Here, we provide the ground truth labels of: cell centers and segmentation, which are used in the publications:</p> <ul> <li>"Learning to Segment: Training Hierarchical Segmentation under a Topological Loss", MICCAI 2015. (DOI: 10.1007/978-3-319-24574-4_32)</li> <li>"Cell Detection and Segmentation Using Correlation Clustering", MICCAI 2014. (DOI: 10.1007/978-3-319-10404-1_2)</li> </ul>
FIGURES 13–15 in Phase-contrast synchrotron microtomography reveals the internal morphology of a new fossil species of the Corticaria-sylvicola - group (Coleoptera: Latridiidae)
FIGURES 13–15. Fossil Latridiidae from Baltic amber: 13—Latridius jantaricus, habitus, dorsal view, specimen "12" [HPR]; 14—Latridius alexeevi, habitus, dorso-frontal view, specimen "16" [HPR]; 15—Revelieria groehni, habitus, dorsal view, specimen "046" [ACAB].
FIGURES 1–2 in Phase-contrast synchrotron microtomography reveals the internal morphology of a new fossil species of the Corticaria-sylvicola - group (Coleoptera: Latridiidae)
FIGURES 1–2. Corticaria amberica sp. nov., holotype "017" [ACAB]: 1—habitus, dorsal view; 2—habitus, ventral view.
FIGURES 10–12 in Phase-contrast synchrotron microtomography reveals the internal morphology of a new fossil species of the Corticaria-sylvicola - group (Coleoptera: Latridiidae)
FIGURES 10–12. Aedeagus: 10—Corticaria pinicola, ventral view (drawing by W.H. Rücker); 11—C. abdominalis, ventral view (drawing by W.H. Rücker); 12—C. amberica sp. nov., lateral and ventral views, reconstruction.
FIGURES 3–5 in Phase-contrast synchrotron microtomography reveals the internal morphology of a new fossil species of the Corticaria-sylvicola - group (Coleoptera: Latridiidae)
FIGURES 3–5. Corticaria amberica sp. nov., holotype "017" [ACAB], phase-contrast synchrotron microtomography renderings (BESSY II, Helmholtz-Zentrum, Berlin): 3—habitus, dorsal, ventral and lateral views; 4—location of aedeagus inside abdomen; 5—aedeagus, lateral and ventral views.
FIGURES 6–9 in Phase-contrast synchrotron microtomography reveals the internal morphology of a new fossil species of the Corticaria-sylvicola - group (Coleoptera: Latridiidae)
FIGURES 6–9. Corticaria amberica sp. nov., paratypes: 6—habitus, dorsal view, paratype "0024/2000" [WRUE]; 7— habitus, dorso-frontal view, paratype "612" [GPIH]; 8—habitus, ventral view, paratype "8216" [GPIH]; 9—habitus, dorsal view, paratype "8059" [HPR].
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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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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.
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