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276 results for “Small population”
Figure 2 in Diurnal activity pattern of age-sex groups of a small and fragmented population of Blackbuck (Antilope cervicapra L.) in Western Haryana, India
Figure 2. (a) Adult male, (b) Sub adult female, (c) Adult females and sub adult
Population genetic assessment of newly discovered, extremely small populations of Xanthocyparis Vietnamensis from southwestern China
<p><i>Xanthocyparis vietnamensis</i> is an endangered species that is currently restricted to karst montane areas in southwestern China and Vietnam. This rare conifer was first recorded in 2002 from northern Vietnam and then in 2013 from Guangxi, China, yet little is known about its genetic diversity and population structure. We developed expressed sequence tag microsatellite markers (EST-SSR) for <i>X. vietnamensis</i>. Illumina HiSeq data were used to reconstruct the transcriptome of this species by de novo assembly. Based on this transcriptome, 20 SSR markers were designed and successfully amplified, and no loci with excessive null allele was detected. These polymorphic loci were then employed to access the genetic diversity and population structure of <i>X. vietnamensis</i>. As well, they could be useful in promoting sustainable forest management strategies for this species in the vulnerable karst ecosystem.</p>
Data from: Decreased selectivity during mate choice in a small-sized population of a long-lived seabird
<p class="western"><span>As</span> biparental care is crucial for breeding success in Procellariiformes seabirds (i.e., albatrosses and petrels), these species are expected to be choosy during pair formation. However, the choice of partners is limited in small-sized populations, which might lead to random pairing. In Procellariiformes, the consequences of such limitations for mating strategies have been examined in <span>a single species</span>. Here, we studied mate choice in another Procellariiforme, Bulwer's petrel <i>Bulweria bulwerii</i><span>,</span> in the Azores (<i>ca </i><span>70 breeding pairs)</span>, where the species has suffered a dramatic population decline. We based our approach on both a 11-year demographic survey (capture-mark-recapture) and a genetic approach (microsatellites, <span>n = </span>127 individuals). The genetic data suggest that this small population is not inbred and did not experience a genetic bottleneck. Moreover, pairing occurred randomly with respect to genetic relatedness, we detected no extrapair parentage (<span>n = </span>35 offspring), and pair fecundity was unrelated to relatedness between partners. From our demographic survey, we detected no assortative mating with respect to body measurements and breeding experience and observed very few divorces, most of which were probably forced. This contrasts with the pattern previously observed in the much larger population from the Selvagens archipelago (assortative mating with respect to bill size and high divorce rate). We suggest that the Bulwer's petrels from the Azores pair with any available partner and retain it as long as possible despite the fact that reproductive performance did not improve with pair common experience, possibly to avoid skipping breeding years in case of divorce. We recommend determining whether decreased choosiness during mate choice also occurs in reduced populations of other Procellariiform species. This might have implications for the conservation of small threatened seabird populations.</p>
Dataset 2 for Large‐ and small‐scale geographic structures affecting genetic patterns across populations of an Alpine butterfly
<p>Understanding factors influencing patterns of genetic diversity and the population genetic structure of species is of particular importance in the current era of global climate change and habitat loss. These factors include the evolutionary history of a species as well as heterogeneity in the environment it occupies, which in turn can change across time. Most studies investigating spatio-temporal genetic patterns have focused on patterns across wide geographical areas rather than local variation, but the latter can nevertheless be important particularly in topographically complex areas. Here we consider these issues in the Sooty Copper butterfly (<i>Lycaena tityrus</i>) from the European Alps, using genome-wide SNPs identified through RADseq. We found strong genetic differentiation within the Alps with four genetic clusters, indicating western, central, and eastern refuges, and a strong reduction of genetic diversity from west to east. This reduction in diversity may suggest that the southwestern refuge was the largest one in comparison to other refuges. Also, the high genetic diversity in the West may result from (1) admixture of different western refuges, (2) more recent demographic changes, or (3) introgression of lowland <i>L. tityrus</i> populations. At small spatial scales, populations were structured by several landscape features and especially by high mountain ridges and large river valleys. We detected 36 outlier loci likely under altitudinal selection, including several loci related to membranes and cellular processes. We suggest that efforts to preserve alpine <i>L. tityrus </i>should focus on the genetically diverse populations in the western Alps, and that the dolomite populations should be treated as genetically distinct management units, since they appear to be currently more threatened than others. This study demonstrates the usefulness of SNP-based approaches for understanding patterns of genetic diversity, gene flow and selection in a region that is expected to be particularly vulnerable to climate change.</p>
Spraints demonstrate small population size and reliance on fishponds for Eurasian otter (Lutra lutra) in Hong Kong
<p><span>Lack of data on population sizes and resource requirements are major impediments to the effective conservation of rare species globally. The conservation of the Eurasian otter (Lutra lutra) in Hong Kong reflects many of these key challenges for elusive and difficult-to-study mammals. It is a rare carnivore that has narrowly escaped extirpation, now surviving within a human-dominated environment. Using sign surveys and spraint analysis, we recorded only 40 fresh spraints from 246 otter signs locations, over four months of intensive sampling across two years. Records were restricted to the Mai Po wetlands, confirming this as the core area for Hong Kong's otter population. Molecular analysis and microsatellite genotyping identified a minimum of seven individuals, two pairs of which were likely related. The genetic and sign data together strongly indicate a small population. Fish dominated the otter diet, highlighting the importance of fishpond habitats as a premium foraging resource. Given the rapid changes surrounding the Mai Po area (especially the new Northern Metropolis Development Strategy), maintaining quality and connected habitats, in addition to sustaining commercial fishponds will be key to otter recovery and long-term population viability in Hong Kong.</span></p>
Aligned and curated mtDNA sequences from: Ancient DNA of narrow-headed voles reveals common features of the Late Pleistocene population dynamics in cold-adapted small mammals
<p><span>Narrow-headed vole, together with collared lemming and common vole, was the most abundant small mammal species across Eurasian Late Pleistocene steppe-tundra environments. Previous ancient DNA studies of </span><span>the latter</span><span> </span><span>two</span><span> revealed dynamic past population histories shaped by climatic fluctuations. To investigate the extent to which species with similar adaptations share common evolutionary </span><span>histories,</span><span> we generated a dataset comprising mitochondrial genomes of 139 ancient and 6 modern narrow-headed voles from multiple sites across Europe and north-</span><span>western</span><span> Asia and covering the last ca. 100 thousand years (ka). We inferred Bayesian time-aware phylogenies using 11 </span><span>radiocarbon-dated</span><span> samples for calibration of the molecular clock. We found that across the three </span><span>species,</span><span> divergence of the main mtDNA lineages occurred during Marine Isotope Stages (MIS) 7 and MIS 5, suggesting a common response </span><span>of species adapted to open habitat to the interglacial environments. </span><span>In European narrow-headed voles, we identified multiple </span><span>time-structured</span><span> mtDNA lineages, implying lineage turnovers. Timing of some of these turnovers was synchronous across all three </span><span>species,</span><span> allowing us to identify the main drivers of the Late Pleistocene dynamics of steppe- and cold-adapted species.</span></p>
Drivers of strong isolation and small effective population size at a leading range edge of a widespread plant
<p>Climate change has influenced species distributions worldwide with upward elevational shifts observed in many systems. Leading range edge populations, like those at upper elevation limits, are crucial for climate change responses but can exhibit low genetic diversity due to founder effects, isolation, or limited outbreeding. These factors can hamper local adaptation at range limits. Using the widespread herb, <em>Argentina</em> <em>anserina</em>, we measured ecological attributes (population density on the landscape, area of population occupancy, and plant and flower density) spanning a 1000m elevation gradient, with high elevation populations at the range limit. We measured vegetative clonal potential in the greenhouse for populations spanning the gradient. We combined these data with a ddRAD-seq dataset to test the hypotheses that high-elevation populations would exhibit ecological and genomic signatures of leading range edge populations. We found that population density on the landscape declined towards the high elevation limit, as is expected towards range edges. However, plant density was elevated within edge populations. In the greenhouse, high-elevation plants exhibited stronger clonal potential than low-elevation plants, likely explaining increased plant density in the field. Phylogeographic analysis supported more recent colonization of high-elevation populations which were also more genetically isolated, had more extreme heterozygote excess, and had smaller effective population size than low. Results support that colonization of high elevations was likely accompanied by increased asexuality, contributing to a decline in effective population size. Despite high plant density in leading-edge populations, their small effective size, isolation, and clonality could constrain adaptive potential.</p>
Data from: Clinical antibiotic-resistance plasmids have small effects on biofilm formation and population growth in Escherichia coli in vitro
<div> <div> <div> <p>Antimicrobial resistance (AR) mechanisms encoded on plasmids can affect other phenotypic traits in bacteria, including biofilm formation. These effects may be important contributors to the spread of AR and the evolutionary success of plasmids, but it is not yet clear how common such effects are for clinical plasmids/bacteria, and how they vary among different plasmids and host strains. Here, we used a combinatorial approach to test the effects of clinical AR plasmids on biofilm formation and population growth in clinical and laboratory Escherichia coli strains. In most of the 25 plasmid-bacterium combinations tested, we observed no significant change in biofilm formation upon plasmid introduction, contrary to the notion that plasmids frequently alter biofilm formation. In a few cases we detected altered biofilm formation, and these effects were specific to particular plasmid-bacterium combinations. By contrast, we found a relatively strong effect of a chromosomal streptomycin-resistance mutation (in rpsL) on biofilm formation. Further supporting weak and host-strain- dependent effects of clinical plasmids on bacterial phenotypes in the combinations we tested, we found growth costs associated with plasmid carriage (measured in the absence of antibiotics) were moderate and varied among bacterial strains. These findings suggest some key clinical resistance plasmids cause only mild phenotypic disruption to their host bacteria, which may contribute to the persistence of plasmids in the absence of antibiotics.</p> </div> </div> </div>
Cancer Vaccine Study for Stage III, Unresectable, Non-small Cell Lung Cancer (NSCLC) in the Asian Population
ClinicalTrials.gov study NCT01015443. IPD Sharing: Not stated. Countries: 5. Publications: 2.
Big cat vcf files from: Exceedingly low genetic diversity in snow leopards due to persistently small population size
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Data from: Pace and parity predict short-term persistence of small plant populations
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Dataset 1 for Large- and small-scale geographic structures affect genetic patterns across populations of an Alpine butterfly
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Data from: Abundance models of endemic birds of the Sierra Nevada de Santa Marta, northern South America, suggest small population sizes and dependence on montane elevations
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Drivers of strong isolation and small effective population size at a leading range edge of a widespread plant
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Data from: Clinical antibiotic-resistance plasmids have small effects on biofilm formation and population growth in Escherichia coli in vitro
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Dataset 2 for Large‐ and small‐scale geographic structures affecting genetic patterns across populations of an Alpine butterfly
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Data from: Variable resistance to spinetoram in populations of Thrips palmi across a small area unconnected to genetic similarity
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Small giants: Tributaries rescue spatially structured populations from extirpation in a highly fragmented stream
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Population genetics of caribou in the Alaska-Yukon border region: implications for designation of conservation units and small herd persistence
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Data from: Small but connected islands can maintain populations and genetic diversity under climate change
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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)
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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.