11. Diversity of the surface microbiome of canopy-forming brown macroalgae (Fucales) in the northern AdriaticNeža Orel, Ana Lokovšek, Martina Orlando-Bonaca, Tinkara Tinta, 2025, izvirni znanstveni članek Povzetek: Canopy-forming brown macroalgae (Fucales) offer numerous key ecosystem services in Mediterranean coastal areas. However, anthropogenic pressures and climate change have significantly impacted their habitats, leading to an extensive population decline. Interactions between algae and microbiota are a major ecological aspect, yet they represent a significant knowledge gap. In our baseline study, we describe the diversity and host specificity of the microbiome of two genetically identical but morphologically distinct populations of Gongolaria barbata from anthropogenically impacted northern Adriatic Sea. Our preliminary results showed that the microbiomes of G. barbata exhibited low host specificity, with 75% of the algae-associated amplicon sequence variants (ASVs) being part of the core coastal ecosystem microbiome. However, microbiomes of specific algal parts, ambient seawater, and sediment differed significantly in terms of alpha diversity and composition. In contrast, the holdfast and axis show higher similarity with sediment microbiomes, indicating potential horizontal transmission pathways. Microbiomes associated with deciduous parts of morphologically distinct G. barbata populations showed no difference in alpha diversity and composition. In contrast, higher variation in alpha diversity and lower sequence proportion of shared ASVs were observed in the holdfast and axis of the two distinct populations. Our observational study provides valuable new insights and baseline for future hypothesis-driven research on the interactions between algae and associated microbiota—a knowledge gap that needs to be addressed in the future for better understanding of the ecological and evolutionary dynamics of coastal ecosystems.
Ključne besede: ecosystem services, anthropogenic pressures, microbiome, host specificity, alpha diversity, marine biology, ecology
Objavljeno v DiRROS: 18.04.2025; Ogledov: 50; Prenosov: 21
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12. Out of Liguria : how polyploidy affected diversification of the sweet spurge (Euphorbia dulcis, Euphorbiaceae), European widespread forest speciesMarija Kravanja, Jasna Dolenc Koce, Božo Frajman, 2025, izvirni znanstveni članek Povzetek: Polyploidy is an important evolutionary mechanism in flowering plants that can strongly affect their morphological and distributional traits. In this study, we investigated the differences in these traits among di-, tri-, and tetraploid populations of sweet spurge (Euphorbia dulcis), a common understory species in deciduous and mixed forests across Europe. We inferred the ploidy of 188 populations of E. dulcis by estimating relative genome size and chromosome counting. The data indicate that tri- and tetraploids are more widespread compared to the ancestral diploid populations, which are restricted to Liguria (north-western Italy) and adjacent regions. We suggest that polyploidisation was crucial for range expansion and the colonisation of higher latitudes, but not for the colonisation of higher elevations, where diploids appear to be more successful. Similarly, morphological differentiation after polyploidisation is only partly consistent with the classical hypothesis that polyploids are larger and have larger organs. Using nuclear ITS and plastid ndhF–trnL sequences, we inferred the spatio-temporal diversification of E. dulcis. It diverged from its diploid sister species E. duvalii, an endemic of southwestern France and adjacent Spain, in the mid-Pliocene. This divergence was likely due to vicariant speciation accompanied by adaptation to forest and grassland environments in E. dulcis and E. duvallii, respectively. Whereas the diploid populations of both taxa have restricted ranges today, polyploidisation within E. dulcis likely triggered by the Pleistocene climatic oscillations contributed to its significant range expansion and diversification. The species exhibits the highest genetic diversity in the south-western Alps, where all three ploidies co-occur. Based on the ploidy differentiation and the less pronounced genetic and morphological differentiation, we propose treating di- and triploids as well as two geographically and genetically divergent groups of tetraploids (eastern and western) as four subspecies. This challenges various taxonomic treatments previously proposed for this species. Our study highlights the importance of polyploidisation for diversification and range expansion, and indicates the necessity of further research to test hypotheses related to the morphological and distributional characteristics of polyploid organisms.
Ključne besede: forest understory species, morphometry, phylogeography, polyploidisation, taxonomy
Objavljeno v DiRROS: 18.04.2025; Ogledov: 44; Prenosov: 15
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13. Neuromotor changes in postural control following bed restRamona Ritzmann, Christoph Centner, Luke Hughes, Janice Waldvogel, Uroš Marušič, 2025, pregledni znanstveni članek Povzetek: Chronic bed rest (BR) serves as a model for studying the effects of prolongedimmobility on physiological and neuromotor functions, particularly postural control. ProlongedBR leads to significant deconditioning of postural balance control, characterized by increasedsway path lengths, sway velocity and fall risk, independent of muscle strength. These changes arelinked to neural adaptations at spinal and supraspinal levels, including structural and functionalbrain changes, such as alterations in grey and white matter, increased cerebellar activation,reduced spinal excitability and increased latencies within reflex circuitries. Additionally, BRdisrupts sensory integration from proprioceptive, visual and vestibular systems, impairing post-ural stability. Visual reliance remains stable during BR, though decreased visual acuity andcontrast sensitivity are noted. Moreover, BR-induced shifts in cerebrospinal fluid contribute toaltered brain activity, impacting sensorimotor function. Vestibular system adaptations, includingchanges in vestibulospinal reflexes, further exacerbate balance impairments. Understanding thesemechanisms is crucial for developing interventions to mitigate the adverse effects of BR onpostural control and prevent prolonged recovery times or increased risk of injury. This reviewhighlights the need for further research into the neural underpinnings of BR-induced posturalinstability, with a focus on sensory integration and neuroplasticity
Ključne besede: atrophy, balance, disuse, immobilization, muscle
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15. Površinska kemija naravnih oksidnih plasti na uporabljenih in novih vzorcih stegneničnih komponent endoproteze kolka iz Ti-6Al-7Nb zlitine : diplomsko deloMatic Petrič, 2023, diplomsko delo Ključne besede: kolčne endoproteze, aseptično omajanje, periprostetična okužba, titanov oksid, polimeri, titanove zlitine, XPS, SEM, EBSD, diplomsko delo
Objavljeno v DiRROS: 18.04.2025; Ogledov: 48; Prenosov: 10
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18. Reactive noble-gas compounds explored by 3D electron diffraction : XeF[sub]2–MnF[sub]4 adducts and a facile sample handling procedureKlemen Motaln, Kshitij Gurung, Petr Brázda, Anton Kokalj, Kristian Radan, Mirela Dragomir, Boris Žemva, Lukáš Palatinus, Matic Lozinšek, 2024, izvirni znanstveni članek Ključne besede: compounds, 3D electron diffraction
Objavljeno v DiRROS: 17.04.2025; Ogledov: 86; Prenosov: 17
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19. Surface engineering of aerospace aluminium alloys : understanding alloying effects on chemical pre-treatment and sol-gel coating adhesionJ.B.P. Van Dam, Urša Tiringer, Shoshan Abrahami, Ingrid Milošev, Herman Terryn, Janez Kovač, Johannes M. C. Mol, 2024, izvirni znanstveni članek Povzetek: The sol–gel process is a chemical surface preparation method based on hydrolysis and polycondensation reactions for enhanced adhesion for metallic substrates in adhesive bonding and coating applications. This paper describes an investigation into the effect of the microstructural complexity of two commonly used aerospace aluminium alloys (AAs) 2024-T3 and 7075-T6, on the response to different surface pre-treatments before deposition of the sol-gel coating and subsequent adhesive bonding. Different surface pre-treatments, including two abrasive treatments and three chemical surface pre-treatments were used, and their effect on surface chemistry, wettability and roughness was assessed. Surfaces were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, profilometry and static contact angles. A hybrid silane sol-gel film was deposited on the differently pre-treated aluminium alloys, an epoxy adhesive was applied and the adhesion properties were evaluated using pull-off testing. The role of the altered physicochemical properties of the pre-treated surfaces was related to the adhesion strength of the sol–gel reinforced epoxy/aluminium interfaces. The microstructural complexity of the aerospace alloys caused non-uniform responses to the pre-treatments, proving the importance of compatibility between material and treatment conditions. Statistical analysis revealed that, despite that overall higher adhesion values were obtained on rougher surfaces, only a strong correlation exists between the surface hydroxyl fraction and adhesion strength. The relation of roughness and water contact angle to interfacial adhesion was found to be non-significant. The findings of this study underscore the critical role of surface pre-treatments and their impact on adhesion strength in aerospace aluminium alloys, providing valuable insights for the effective utilization of sol-gel coatings in adhesive bonding and coating processes.
Ključne besede: sol-gel, surface pre-treatment, surface morphology, wettability, adhesive
Objavljeno v DiRROS: 17.04.2025; Ogledov: 61; Prenosov: 16
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20. Complementary corrosion protection of cast AlSi7Mg0.3 alloy using Zr-Cr conversion and polyacrylic/siloxane-silica multilayer coatingsPeter Rodič, Barbara Kapun, Ingrid Milošev, 2024, izvirni znanstveni članek Povzetek: Aluminium cast alloy AlSi7Mg0.3 is a lightweight metal commonly used in automotive, aeronautical and mechanical applications. It has good corrosion resistance but, under harsh operative conditions, would benefit from additional protection. In this study, a corrosion-protective multilayer coating system for AlSi7Mg0.3 based on hexafluoro-zirconated trivalent chromium coating (Zr-CrCC) and polyacrylic/siloxane-silica (PEHA-SS) coating was developed. The Zr-CrCC was formed by immersion of the substrate in a commercial conversion bath (SurTec® 650). PEHA-SS synthesis was based on organic precursors (2-ethylhexyl acrylate and [3-(methacryloyloxy)propyl]trimethoxysilane) and an inorganic precursor, tetraethyl orthosilicate. After deposition on AlSi7Mg0.3, each coating was first characterised individually, followed by the analysis of the multilayer using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The adhesion of the coatings was evaluated with a cross-hatch cut test. The corrosion studies in sodium chloride solution using electrochemical impedance spectroscopy and salt spray testing showed that the multilayer system is superior to individual Zr-CrCC and PEHA-SS coatings. After 4 months in 0.1 M NaCl, the multilayer-coated samples exhibited the impedance at 10 mHz in the range of GΩ cm2, while scribed samples withstood the corrosion attack in a salt spray chamber for one week. Thus, albeit only about 100 nm thick, the Zr-CrCC deposited between the substrate and a 9-micrometre thick barrier sol-gel PEHA-SS coating acts as an active corrosion protection interlayer and contributes to the overall protectiveness of the multilayer system.
Ključne besede: corrosion-protective, aluminium, material
Objavljeno v DiRROS: 17.04.2025; Ogledov: 60; Prenosov: 24
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