2,568 research outputs found

    Leaf, tree and soil properties in a Eucalyptus saligna forest exhibiting canopy decline

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    The extent of eucalypt decline in moist coastal forests of south-eastern Australia is increasing with resultant losses in biodiversity and productivity. This survey aimed to identify factors associated with the decline of Eucalyptus saligna (Sydney Blue Gum) in Cumberland State Forest, a moist sclerophyll forest within urban Sydney. Eucalyptus saligna was the dominant overstorey species in six 20 m radius plots, which differed in floristic composition, structure and crown condition. One plot was colonised by bell miners (Manorina melanophrys). A range of leaf, tree and plot scale parameters were assessed including insect damage and free amino acid content, visual crown condition, floristics and soil chemistry. The plot permanently colonised by bell miners also had Eucalyptus saligna trees in the poorest condition. Both the weed Lantana camara and the soil pathogen Phytophthora cinnamomi were present in some of the plots but neither was strongly consistent with the severity of crown decline. There were, however, significant correlations among the foliar traits of insect damage, free amino acid content and relative chlorophyll content. Free amino acid content differed significantly between leaf age cohorts. Plots differed notably in topsoil organic matter and soil nitrogen, but the plot with the poorest visual crown condition score had intermediate mean values for both soil properties within the ranges presented by the six plots. Overall, crown condition score was weakly negatively correlated with topsoil organic carbon and total nitrogen content. The unhealthiest plot also had the highest density of shrubby understorey. Site factors that could influence both the quantity and quality of foliage (e.g. free amino acid content) in eucalypt crowns, and hence the population dynamics of herbivorous insects and bell miners, are discussed in relation to Eucalyptus saligna crown decline

    A tale of two tissues:Probing gene expression in a complex insect-induced gall

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    Plant galls are novel and sometimes dramatic plant organs whose development is initiated and controlled by parasitic microbes, nematodes, insects and mites. For arthropods, galls provide relative safety from enemies and abiotic stresses while providing nutrition. Galls are formed entirely by the plant, whose transcriptional pathways are modified and coopted to produce a structure specific to the galler species; they comprise a classic example of Dawkins’ “extended phenotype”. Arthropod‐elicited galls are unique in that they are often anatomically complex (Figure 1a), with multiple differentiated tissue types (Figure 1b). A growing number of investigators have studied changes in hostplant gene expression to understand arthropod gall development. In this issue of Molecular Ecology, Martinson et al. (2021) report using RNA sequencing to explore tissue‐specific gene expression associated with anatomical and functional gall complexity, demonstrating for the first time that gall tissues are as different transcriptionally as they are anatomically

    A Handbook for Lightboard Technology in the Kinesiology Classroom

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    Presenting pedagogical content on a digital platform is commonplace in the 21st century classroom. Now, presentations are given virtually to students who are learning both synchronously and asynchronously. With students learning from a distance, faculty must find means to elevate their delivery to foster engagement on an easily disconnected platform, thus winning the competition for their attention. Use of Lightboard technology meets the need to deliver innovative teaching and learning, but it is also simple for the faculty to use. This manuscript outlines the process of setting up, managing, and producing media from a Lightboard studio. We provide the framework needed to propose funding for this resource, building plans, as well as capture and editing tutorials to lessen the burden on faculty wishing to bring this technology to their campus. This fully online medium supports any classroom instruction (face-to-face, hybrid, and online), and with proper planning, can save the faculty’s time on reviewing concepts in and out of class periods. Lightboard studios are often shared across the campus community, potentially leading to long wait times for recording and impaired flexibility for rapid content production. In this resource, we document how smaller units (colleges, departments, and programs) can justify investing in this innovative technology

    Strategic Behavior, Real Rigidities, and Production Coordination Failures

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    This paper develops a real-exchange production-coordination model in which price-setting firms produce complementary inputs that are converted into and traded for a final good produced by a competitive sector. A rigid real-price regime is shown to be consistent with both rational firm behavior and welfare-ranked Nash equilibria, although not with a Pareto optimal equilibrium. The model demonstrates the existence of non-unique, sustainable real-price sets for various coordinated-production levels with a unique price set at a sustainable maximum output level. Without both production and price coordination, the model may produce a Nash equilibrium at a low output level.Prices

    Ecoacoustics as a novel tool for assessing pond restoration success:Results of a pilot study

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    1. Ecoacoustics is increasingly being used to monitor species populations and to estimate biodiversity in marine ecosystems, but the underwater soundscapes of freshwater environments remain largely unexplored in this respect. Few studies exist concerning the acoustic diversity of ponds, but because aquatic plants and many arthropods such as Coleoptera and Hemiptera are known to produce sound, there is potential to use ecoacoustic techniques to monitor changes in biodiversity and conservation value. 2. This pilot study compares the underwater soundscapes of recently restored open-canopy ponds and unmanaged highly terrestrialized ponds situated in an arable agricultural landscape of North Norfolk, UK, in order to assess the benefits of farmland pond restoration. 3. Daytime sound recordings were made for 10 min in each pond and analysed primarily for arthropod stridulations. In addition, six commonly used acoustic indices were calculated to assess the soundscape biodiversity between the unmanaged and the restored ponds. The stridulations of three diving beetle species (Dytiscidae) were recorded in tank studies to assess the potential for individual species recognition from underwater sound capture. 4. Sound-type richness and abundance, as estimated by visually and aurally identifying arthropod stridulation from spectrograms, were significantly higher in the restored open-canopy ponds compared with the unmanaged terrestrialized ponds. In addition, the acoustic indices ‘acoustic complexity’ and ‘biodiversity index’ were significantly higher in restored open-canopy ponds than in unmanaged terrestrialized ponds. 5. The three dytiscid water beetle species recorded in a tank were found to produce distinctive and recognizable sounds, indicating potential to create an audio reference library that could be used for automatic acoustic monitoring of freshwater arthropods. 6. Pond soundscapes are rich in biological information and this study suggests that, with further development, automated passive ecoacoustic monitoring could be an effective non-invasive technique for assessing pond conservation value and pond restoration and management success

    An improved method for surface immobilisation of RNA: application to small Non-Coding RNA - mRNA pairing

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    Characterisation of RNA and its intermolecular interactions is increasing in importance as the inventory of known RNA functions continues to expand. RNA-RNA interactions are central to post-transcriptional gene regulation mechanisms in bacteria, and the interactions of bacterial small non-coding RNAs (sRNAs) with their mRNA targets are the subject of much current research. The technology of surface plasmon resonance (SPR) is an attractive approach to studying these interactions since it is highly sensitive, and allows interaction measurements to be recorded in real-time. Whilst a number of approaches exist to label RNAs for surface-immobilisation, the method documented here is simple, quick, efficient, and utilises the high-affinity streptavidin-biotin interaction. Specifically, we ligate a biotinylated nucleotide to the 3' end of RNA using T4 RNA ligase. Although this is a previously recognised approach, we have optimised the method by our discovery that the incorporation of four or more adenine nucleotides at the 3' end of the RNA (a poly-A-tail) is required in order to achieve high ligation efficiencies. We use this method within the context of investigating small non-coding RNA (sRNA)-mRNA interactions through the application of surface technologies, including quantitative SPR assays. We first focus on validating the method using the recently characterised Escherichia coli sRNA-mRNA pair, MicA-ompA, specifically demonstrating that the addition of the poly-A-tail to either RNA does not affect its subsequent binding interactions with partner molecules. We then apply this method to investigate the novel interactions of a Vibrio cholerae Qrr sRNA with partner mRNAs, hapR and vca0939; RNA-RNA pairings that are important in mediating pathogenic virulence. The calculated binding parameters allow insights to be drawn regarding sRNA-mRNA interaction mechanisms
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