135 research outputs found

    Unlocking the potential of ancient fish DNA in the genomic era.

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    Fish are the most diverse group of vertebrates, fulfil important ecological functions and are of significant economic interest for aquaculture and wild fisheries. Advances in DNA extraction methods, sequencing technologies and bioinformatic applications have advanced genomic research for nonmodel organisms, allowing the field of fish ancient DNA (aDNA) to move into the genomics era. This move is enabling researchers to investigate a multitude of new questions in evolutionary ecology that could not, until now, be addressed. In many cases, these new fields of research have relevance to evolutionary applications, such as the sustainable management of fisheries resources and the conservation of aquatic animals. Here, we focus on the application of fish aDNA to (a) highlight new research questions, (b) outline methodological advances and current challenges, (c) discuss how our understanding of fish ecology and evolution can benefit from aDNA applications and (d) provide a future perspective on how the field will help answer key questions in conservation and management. We conclude that the power of fish aDNA will be unlocked through the application of continually improving genomic resources and methods to well-chosen taxonomic groups represented by well-dated archaeological samples that can provide temporally and/or spatially extensive data sets

    A subset of NSAIDs lower amyloidogenic Aβ42 independently of cyclooxygenase activity

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    Epidemiological studies have documented a reduced prevalence of Alzheimer's disease among users of nonsteroidal anti-inflammatory drugs (NSAIDs). It has been proposed that NSAIDs exert their beneficial effects in part by reducing neurotoxic inflammatory responses in the brain, although this mechanism has not been proved. Here we report that the NSAIDs ibuprofen, indomethacin and sulindac sulphide preferentially decrease the highly amyloidogenic Aβ42 peptide (the 42-residue isoform of the amyloid-β peptide) produced from a variety of cultured cells by as much as 80%. This effect was not seen in all NSAIDs and seems not to be mediated by inhibition of cyclooxygenase (COX) activity, the principal pharmacological target of NSAIDs. Furthermore, short-term administration of ibuprofen to mice that produce mutant β-amyloid precursor protein (APP) lowered their brain levels of Aβ42. In cultured cells, the decrease in Aβ42 secretion was accompanied by an increase in the Aβ(1–38) isoform, indicating that NSAIDs subtly alter γ-secretase activity without significantly perturbing other APP processing pathways or Notch cleavage. Our findings suggest that NSAIDs directly affect amyloid pathology in the brain by reducing Aβ42 peptide levels independently of COX activity and that this Aβ42-lowering activity could be optimized to selectively target the pathogenic Aβ42 species

    Negative outcomes evoke cyclic irrational decisions in Rock, Paper, Scissors

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    Rock, Paper, Scissors (RPS) represents a unique gaming space in which the predictions of human rational decision-making can be compared with actual performance. Playing a computerized opponent adopting a mixed-strategy equilibrium, participants revealed a non-significant tendency to over-select Rock. Further violations of rational decision-making were observed using an inter-trial analysis where participants were more likely to switch their item selection at trial n + 1 following a loss or draw at trial n, revealing the strategic vulnerability of individuals following the experience of negative rather than positive outcome. Unique switch strategies related to each of these trial n outcomes were also identified: after losing participants were more likely to ‘downgrade’ their item (e.g., Rock followed by Scissors) but after drawing participants were more likely to ‘upgrade’ their item (e.g., Rock followed by Paper). Further repetition analysis revealed that participants were more likely to continue their specific cyclic item change strategy into trial n + 2. The data reveal the strategic vulnerability of individuals following the experience of negative rather than positive outcome, the tensions between behavioural and cognitive influences on decision making, and underline the dangers of increased behavioural predictability in other recursive, non-cooperative environments such as economics and politics

    Genetically encoded sender-receiver system in 3D mammalian cell culture

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    Engineering spatial patterning in mammalian cells, employing entirely genetically encoded components, requires solving several problems. These include how to code secreted activator or inhibitor molecules and how to send concentration-dependent signals to neighboring cells, to control gene expression. The Madin-Darby Canine Kidney (MDCK) cell line is a potential engineering scaffold as it forms hollow spheres (cysts) in 3D culture and tubulates in response to extracellular hepatocyte growth factor (HGF). We first aimed to graft a synthetic patterning system onto single developing MDCK cysts. We therefore developed a new localized transfection method to engineer distinct sender and receiver regions. A stable reporter line enabled reversible EGFP activation by HGF and modulation by a secreted repressor (a truncated HGF variant, NK4). By expanding the scale to wide fields of cysts, we generated morphogen diffusion gradients, controlling reporter gene expression. Together, these components provide a toolkit for engineering cell-cell communication networks in 3D cell culture.Facultad de Ciencias Exacta

    Regioselective synthesis of plant (iso)flavone glycosides in Escherichia coli

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    The flavonoids genistein, biochanin A, luteolin, quercetin, and kaempferol are plant natural products with potentially useful pharmacological and nutraceutical activities. These natural products usually exist in plants as glycosides, and their glycosylation has a remarkable influence on their pharmacokinetic properties. The glycosyltransferases UGT71G1 and UGT73C8 from Medicago truncatula are excellent reagents for the regioselective glycosylation of (iso)flavonoids in Escherichia coli grown in Terrific broth. Ten to 20 mg/L of either genistein or biochanin A 7-O-glucoside was produced after feeding genistein or biochanin A to E. coli expressing UGT71G1, and similar levels of luteolin 4’-O- and 7-O-glucosides were produced after feeding luteolin to cultures expressing UGT73C8. For the production of kaempferol 3-O-glucoside or quercetin 3-O-glucoside, the Phe148Val or Tyr202Ala mutants of UGT71G1 were employed. Ten to 16 mg/L of either kaempferol 3-O- or quercetin 3-O-glucosides were produced on feeding kaempferol or quercetin to E. coli expressing these enzymes. More than 90% of the glucoside products were released to the medium, facilitating their isolation

    Computing with bacterial constituents, cells and populations: from bioputing to bactoputing

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    The relevance of biological materials and processes to computing—aliasbioputing—has been explored for decades. These materials include DNA, RNA and proteins, while the processes include transcription, translation, signal transduction and regulation. Recently, the use of bacteria themselves as living computers has been explored but this use generally falls within the classical paradigm of computing. Computer scientists, however, have a variety of problems to which they seek solutions, while microbiologists are having new insights into the problems bacteria are solving and how they are solving them. Here, we envisage that bacteria might be used for new sorts of computing. These could be based on the capacity of bacteria to grow, move and adapt to a myriad different fickle environments both as individuals and as populations of bacteria plus bacteriophage. New principles might be based on the way that bacteria explore phenotype space via hyperstructure dynamics and the fundamental nature of the cell cycle. This computing might even extend to developing a high level language appropriate to using populations of bacteria and bacteriophage. Here, we offer a speculative tour of what we term bactoputing, namely the use of the natural behaviour of bacteria for calculating

    Quorum sensing:Implications on rhamnolipid biosurfactant production

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    Introduction of Ophiobolus graminis into new polders and its decline

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    Designar Comissão Interna para Elaboração do Inventário Físico dos bens móveis do NÚCLEO DE DESENVOLVIMENTO INFANTIL do CENTRO DE CIÊNCIAS DA EDUCAÇÃO (NDI/CED), referente ao exercício 2018
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