22 research outputs found

    Maltese teachers’ beliefs concerning the integration of children’s literature in mathematics teaching and learning

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    This exploratory mixed-methods study set out to explore Maltese primary school teachers’ perceived barriers to, and enablers for, the integration of children’s literature in mathematics teaching. Data were collected by means of an online questionnaire and semi-structured interviews, and analysed thematically using Ajzen’s Theory of Planned Behaviour. The responses given by the participants showed that integration of mathematics and stories was not a common practice. The perceived barriers were categorised as Resource Constraint, Time Constraint, Lack of Pedagogical Knowledge and Confidence, Doubts about Outcome Expectancy, and Inhibiting Social Norms while the three perceived enablers identified were Pedagogical Benefits, Love of Stories, and Enabling Social Norms. Given that the majority of the participating teachers acknowledged the potential benefits of the approach and expressed a wish for training, one key recommendation of the study is for teaching mathematics through stories to be explicitly included in pre-service and in-service professional development programmes

    Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

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    Dengue virus causes ∼50–100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture

    Sixteen diverse laboratory mouse reference genomes define strain-specific haplotypes and novel functional loci.

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    We report full-length draft de novo genome assemblies for 16 widely used inbred mouse strains and find extensive strain-specific haplotype variation. We identify and characterize 2,567 regions on the current mouse reference genome exhibiting the greatest sequence diversity. These regions are enriched for genes involved in pathogen defence and immunity and exhibit enrichment of transposable elements and signatures of recent retrotransposition events. Combinations of alleles and genes unique to an individual strain are commonly observed at these loci, reflecting distinct strain phenotypes. We used these genomes to improve the mouse reference genome, resulting in the completion of 10 new gene structures. Also, 62 new coding loci were added to the reference genome annotation. These genomes identified a large, previously unannotated, gene (Efcab3-like) encoding 5,874 amino acids. Mutant Efcab3-like mice display anomalies in multiple brain regions, suggesting a possible role for this gene in the regulation of brain development

    Teoria do valor: bases para um método

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    Mass spectrometry imaging of mating Tetrahymena show that changes in cell morphology regulate lipid domain formation

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    Mass spectrometry imaging has been used here to suggest that changes in membrane structure drive lipid domain formation in mating single-cell organisms. Chemical studies of lipid bilayers in both living and model systems have revealed that chemical composition is coupled to localized membrane structure. However, it is not clear if the lipids that compose the membrane actively modify membrane structure or if structural changes cause heterogeneity in the surface chemistry of the lipid bilayer. We report that time-of-flight secondary ion mass spectrometry images of mating Tetrahymena thermophila acquired at various stages during mating demonstrate that lipid domain formation, identified as a decrease in the lamellar lipid phosphatidylcholine, follows rather than precedes structural changes in the membrane. Domains are formed in response to structural changes that occur during cell-to-cell conjugation. This observation has wide implications in all membrane processes
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