Iskanje po repozitoriju

Opis: Effective population size (Ne) is one of the most important parameters in evolutionary biology, as it is linked to the long-term survival capability of species. Therefore, Ne greatly interests conservation geneticists, but it is also very relevant to policymakers, managers, and conservation practitioners. Molecular methods to estimate Ne rely on various assumptions, including no immigration, panmixia, random sampling, absence of spatial genetic structure, and/or mutation-drift equilibrium. Species are, however, often characterized by fragmented populations under changing environmental conditions and anthropogenic pressure. Therefore, the estimation methods' assumptions are seldom addressed and rarely met, possibly leading to biased and inaccurate Ne estimates. To address the challenges associated with estimating Ne for conservation purposes, the COST Action 18134, Genomic Biodiversity Knowledge for Resilient Ecosystems (G-BiKE), organized an international workshop that met in August 2022 in Brașov, Romania. The overarching goal was to operationalize the current knowledge of Ne estimation methods for conservation practitioners and decision-makers. We set out to identify datasets to evaluate the sensitivity of Ne estimation methods to violations of underlying assumptions and to develop data analysis strategies that addressed pressing issues in biodiversity monitoring and conservation. Referring to a comprehensive body of scientific work on Ne, this meeting report is not intended to be exhaustive but rather to present approaches, workshop findings, and a collection of papers that serve as fruits of those efforts. We aimed to provide insights and opportunities to help bridge the gap between scientific research and conservation practice.
Ključne besede: Ne, effective population size, inbreeding
Objavljeno v RUP: 04.02.2026; Ogledov: 138; Prenosov: 0
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Opis: The marine environment comprises vast regions without physical barriers to movement, making the understanding of population isolation and the evolution of diversity challenging. This is especially the case for highly mobile marine species. Here we investigate populations of the common bottlenose dolphin (Tursiops truncatus) across the Mediterranean Sea and adjacent North Atlantic using high-resolution genomic markers (RADseq) and stable isotope analyses to better understand the evolution of population structure in this system. High-resolution genomic data and broad geographic sampling revealed patterns of structure not previously identified, and integration with stable isotope data suggests that prey choice varies across this region. Unexpected patterns included genetic and isotopic similarity between the North Atlantic and the region around Sicily (but not including the medially located Gulf of Cádiz and surrounding regions). The regional habitat within and beyond the Mediterranean Sea is structured with ocean frontal systems including thermal and halocline transitions, several of which show alignment with genetic transitions within our data. Our data help to distinguish among possible drivers of population differentiation for a marine predator that has the potential for long-distance dispersion. 1 Introduction
Ključne besede: genomics, phylogeography, population structure, stable isotopes, Tursiops truncatus
Objavljeno v RUP: 27.12.2025; Ogledov: 317; Prenosov: 0
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Opis: Helichrysum italicum (Roth) G. Don (Asteraceae) is a valuable medicinal and aromatic plant native to a variety of habitats across the Mediterranean region. However, genetic studies of this morphologically diverse species have been limited by the scarcity of species-specific DNA markers. To address this limitation, we generated the first de novo transcriptome assembly comprising 24,806 transcripts from young shoots containing leaves and flowers, developed EST-SSR markers, and evaluated their utility in population genetic analysis. Seventy-eight primer pairs were designed, of which 23 showed successful amplification, polymorphism, and transferability to Helichrysum litoreum Guss. and Helichrysum arenarium (L.) Moench. A subset of 12 EST-SSRs was used to genotype 270 individuals from 12 natural populations of H. italicum in Corsica (France), along with one outgroup population from Croatia. The polymorphic information content ranged from 0.250 to 0.796, and Shannon’s information index ranged from 0.588 to 1.843, indicating the markers’ suitability for popu- lation genetic studies. Analysis of molecular variance revealed that 15% of the total genetic variation was attributable to differences among populations. Discriminant analysis of principal components and Bayesian clustering in STRUCTURE identified distinct popu- lation clusters corresponding to geographic locations. Notably, the southernmost coastal populations were clearly differentiated from the others.
Ključne besede: Helichrysum italicum, immortelle, de novo transcriptome, genic microsatellite markers, EST-SSRs, population study, Corsica, Mediterranean Basin
Objavljeno v RUP: 17.12.2025; Ogledov: 272; Prenosov: 7
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Opis: Cognitive tasks significantly influence automated acts, such as walking. This study included 41 healthy individuals, who were over 65 years of age. We examined dual-task effects on the spatiotemporal and kinematic parameters of gait in older adults during four tasks carried out in single-task, cognitive, motor, and combined cognitive–motor conditions. An analysis of walking according to spatiotemporal and kinematic parameters was performed using an inertial movement analysis system. The combined task showed the most significant impairments, with substantially reduced gait speed (p < 0.001, r = −0.80), shorter stride length (p < 0.001, r = −0.82), and decreased hip flexion (p < 0.001, r = −0.80) compared to single-task walking. Cognitive tasks alone significantly affected gait speed (p = 0.001) and stride length (p = 0.001), while motor tasks showed minimal effects. The combined task also significantly increased double-support time (p < 0.001) and reduced single-support time (p = 0.001), indicating compensatory walking strategies. These findings demonstrate that concurrent cognitive–motor demands disproportionately impair gait, suggesting that clinical assessments should prioritize combined-task evaluation. The observed kinematic and spatiotemporal changes highlight the profound interdependence between cognitive function and automatic locomotor control during walking. It is likely that dual-task gait analysis may offer clinical utility for the early detection of cognitive–motor deficits.
Ključne besede: spatiotemporal parameters, gait deterioration, aging population
Objavljeno v RUP: 30.06.2025; Ogledov: 716; Prenosov: 3
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Ključne besede: polyps, aurelia aurita, population dynamics, polyp density, density-dependent effects, density-independent effects, modelling, carrying capacity, growth rate
Objavljeno v RUP: 19.07.2021; Ogledov: 3329; Prenosov: 27
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