276 research outputs found

    The effectiveness of protocols when pre-service teachers engage in online collaborations: An exploration

    Get PDF
    Graduate teachers in Australia are expected to engage with their peers to expand their professional learning. Learning to use protocols – or structured professional conversations – provides pre-service teachers with opportunities to achieve this expectation. In this paper we explain how pre-service teachers during an extended practicum used protocols to participate in synchronous online discussions using the Blackboard Collaborate learning platform. The pre-service teachers were surveyed about aspects of the protocols and the platform on which the interactions occurred. Protocols appear to be well-suited to assisting synchronous discussions using Web 2 technologies as they ensure everyone has equal time to discuss, present and receive feedback about their work in respectful and efficient ways. This preliminary research provides opportunities for further investigation of pedagogical approaches to use with pre-service teachers when they are required to utilise online platforms when they are away from the university for extended periods of time

    An Atlas of human kinase regulation

    No full text
    The coordinated regulation of protein kinases is a rapid mechanism that integrates diverse cues and swiftly determines appropriate cellular responses. However, our understanding of cellular decision-making has been limited by the small number of simultaneously monitored phospho- regulatory events. Here, we have estimated changes in activity in 215 human kinases in 399 condi- tions from a compilation of nearly 3 million phosphopeptide quantifications. This atlas identifies commonly regulated kinases as those that are central in the signaling network and defines the logic relationships between kinase pairs. Co-regulation along the conditions predicts kinase-complex and kinase-substrate associations. Additionally, the kinase regulation profile acts as a molecular fingerprint to identify related and opposing signaling states. Using this atlas, we identified essen- tial mediators of stem cell differentiation, modulators of Salmonella infection and new targets of AKT1. This provides a global view of human phosphorylation-based signaling and the necessary context to better understand kinase driven decision-making

    The gut microbiota influences skeletal muscle mass and function in mice

    Get PDF
    The functional interactions between the gut microbiota and the host are important for host physiology, homeostasis, and sustained health. We compared the skeletal muscle of germ-free mice that lacked a gut microbiota to the skeletal muscle of pathogen-free mice that had a gut microbiota. Compared to pathogen-free mouse skeletal muscle, germ-free mouse skeletal muscle showed atrophy, decreased expression of insulin-like growth factor 1, and reduced transcription of genes associated with skeletal muscle growth and mitochondrial function. Nuclear magnetic resonance spectrometry analysis of skeletal muscle, liver, and serum from germ-free mice revealed multiple changes in the amounts of amino acids, including glycine and alanine, compared to pathogen-free mice. Germ-free mice also showed reduced serum choline, the precursor of acetylcholine, the key neurotransmitter that signals between muscle and nerve at neuromuscular junctions. Reduced expression of genes encoding Rapsyn and Lrp4, two proteins important for neuromuscular junction assembly and function, was also observed in skeletal muscle from germ-free mice compared to pathogen-free mice. Transplanting the gut microbiota from pathogen-free mice into germ-free mice resulted in an increase in skeletal muscle mass, a reduction in muscle atrophy markers, improved oxidative metabolic capacity of the muscle, and elevated expression of the neuromuscular junction assembly genes Rapsyn and Lrp4 Treating germ-free mice with short-chain fatty acids (microbial metabolites) partly reversed skeletal muscle impairments. Our results suggest a role for the gut microbiota in regulating skeletal muscle mass and function in mice

    Making teacher educators’ experiences visible: seeing inside the hopeful and ambiguous dimensions of practice

    Get PDF
    The field of teacher education is subject to intense scrutiny and policy reform and within this context, the voices of those working within the field are often marginalised. Drawing on our larger study of teacher educators, we addressed the key research question: “How do those who work in the field of teacher education articulate and represent the nature of their work?.” Using a fusion of arts-based and data science research methods and the theory of practice architectures, we examined the ways that teacher educators’ work is mediated within cultural-discursive, material-economic, and social-political domains. We argue that while ambiguous dimensions exist in teacher educators’ practices, they remain hopeful about their work and find spaces to create alternative sayings, doings and relatings as they prepare teachers for the profession. We contend that using both text-based and visual images facilitates the generation of enhanced meanings to highlight the complexity of teacher educators’ work to those within and outside the profession. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

    Global dissemination of a multidrug resistant Escherichia coli clone.

    Get PDF
    Escherichia coli sequence type 131 (ST131) is a globally disseminated, multidrug resistant (MDR) clone responsible for a high proportion of urinary tract and bloodstream infections. The rapid emergence and successful spread of E. coli ST131 is strongly associated with several factors, including resistance to fluoroquinolones, high virulence gene content, the possession of the type 1 fimbriae FimH30 allele, and the production of the CTX-M-15 extended spectrum β-lactamase (ESBL). Here, we used genome sequencing to examine the molecular epidemiology of a collection of E. coli ST131 strains isolated from six distinct geographical locations across the world spanning 2000-2011. The global phylogeny of E. coli ST131, determined from whole-genome sequence data, revealed a single lineage of E. coli ST131 distinct from other extraintestinal E. coli strains within the B2 phylogroup. Three closely related E. coli ST131 sublineages were identified, with little association to geographic origin. The majority of single-nucleotide variants associated with each of the sublineages were due to recombination in regions adjacent to mobile genetic elements (MGEs). The most prevalent sublineage of ST131 strains was characterized by fluoroquinolone resistance, and a distinct virulence factor and MGE profile. Four different variants of the CTX-M ESBL-resistance gene were identified in our ST131 strains, with acquisition of CTX-M-15 representing a defining feature of a discrete but geographically dispersed ST131 sublineage. This study confirms the global dispersal of a single E. coli ST131 clone and demonstrates the role of MGEs and recombination in the evolution of this important MDR pathogen

    Ras GTPase-like protein MglA, a controller of bacterial social-motility in Myxobacteria, has evolved to control bacterial predation by Bdellovibrio

    Get PDF
    Bdellovibrio bacteriovorus invade Gram-negative bacteria in a predatory process requiring Type IV pili (T4P) at a single invasive pole, and also glide on surfaces to locate prey. Ras-like G-protein MglA, working with MglB and RomR in the deltaproteobacterium Myxococcus xanthus, regulates adventurous gliding and T4P-mediated social motility at both M. xanthus cell poles. Our bioinformatic analyses suggested that the GTPase activating protein (GAP)-encoding gene mglB was lost in Bdellovibrio, but critical residues for MglABd GTP-binding are conserved. Deletion of mglABd abolished prey-invasion, but not gliding, and reduced T4P formation. MglABd interacted with a previously uncharacterised tetratricopeptide repeat (TPR) domain protein Bd2492, which we show localises at the single invasive pole and is required for predation. Bd2492 and RomR also interacted with cyclic-di-GMP-binding receptor CdgA, required for rapid prey-invasion. Bd2492, RomRBd and CdgA localize to the invasive pole and may facilitate MglA-docking. Bd2492 was encoded from an operon encoding a TamAB-like secretion system. The TamA protein and RomR were found, by gene deletion tests, to be essential for viability in both predatory and non-predatory modes. Control proteins, which regulate bipolar T4P-mediated social motility in swarming groups of deltaproteobacteria, have adapted in evolution to regulate the anti-social process of unipolar prey-invasion in the “lone-hunter” Bdellovibrio. Thus GTP-binding proteins and cyclic-di-GMP inputs combine at a regulatory hub, turning on prey-invasion and allowing invasion and killing of bacterial pathogens and consequent predatory growth of Bdellovibrio

    Traversing Learning and Leading Collaboration : Stepping Towards New Power Values During Turbulent and In-Between Times

    Get PDF
    In this chapter, we consider how perspectives about leadership, debates related to higher education, health promotion principles, and frameworks of new and old power informed our work as a group of disparate academic and professional staff who were identified to establish a’Digital Taskforce’ (DT) during the global pandemic. The role of the DT was to support teaching staff in Melbourne Graduate School of Education as it moved rapidly to remote and online teaching. By exploring aspects of our work together within the ecologies of policy, systems, groups, and individuals, we identify key elements of responding and bringing about change as a group of leaders during that turbulent time. Through our collaborative narrative, we also ponder how facets of our work may inform emergent ideas about the scholarship of teaching and learning and the possibilities for rethinking higher education

    Outer membrane protein folding from an energy landscape perspective

    Get PDF
    The cell envelope is essential for the survival of Gram-negative bacteria. This specialised membrane is densely packed with outer membrane proteins (OMPs), which perform a variety of functions. How OMPs fold into this crowded environment remains an open question. Here, we review current knowledge about OFMP folding mechanisms in vitro and discuss how the need to fold to a stable native state has shaped their folding energy landscapes. We also highlight the role of chaperones and the β-barrel assembly machinery (BAM) in assisting OMP folding in vivo and discuss proposed mechanisms by which this fascinating machinery may catalyse OMP folding

    Species-specific activity of antibacterial drug combinations

    Get PDF
    International audienceThe spread of antimicrobial resistance has become a serious public health concern, making once treatable diseases deadly again and undermining breakthrough achievements of modern medicine 1,2. Drug combinations can aid in fighting multi-drug resistant (MDR) bacterial infections, yet, are largely unexplored and rarely used in clinics. To identify general principles for antibacterial drug combinations and understand their potential, we profiled ~3,000 dose-resolved combinations of antibiotics, human-targeted drugs and food additives in 6 strains from three Gram-negative pathogens, Escherichia coli, Salmonella Typhimurium and Pseudomonas aeruginosa. Despite their phylogenetic relatedness, more than 70% of the detected drug-drug interactions are species-specific and 20% display strain specificity, revealing a large potential for narrow-spectrum therapies. Overall, antagonisms are more common than synergies and occur almost exclusively between drugs targeting different cellular processes, whereas synergies are more conserved and enriched in drugs targeting the same process. We elucidate mechanisms underlying this dichotomy and further use our resource to dissect the interactions of the food additive, vanillin. Finally, we demonstrate that several synergies are effective against MDR clinical isolates in vitro and during Galleria mellonella infections with one reverting resistance to the last-resort antibiotic, colistin

    Effective assembly of fimbriae in Escherichia coli depends on the translocation assembly module nanomachine

    Get PDF
    Outer membrane proteins are essential for Gram-negative bacteria to rapidly adapt to changes in their environment. Intricate remodelling of the outer membrane proteome is critical for bacterial pathogens to survive environmental changes, such as entry into host tissues1,​2,​3. Fimbriae (also known as pili) are appendages that extend up to 2 μm beyond the cell surface to function in adhesion for bacterial pathogens, and are critical for virulence. The best-studied examples of fimbriae are the type 1 and P fimbriae of uropathogenic Escherichia coli, the major causative agent of urinary tract infections in humans. Fimbriae share a common mode of biogenesis, orchestrated by a molecular assembly platform called ‘the usher’ located in the outer membrane. Although the mechanism of pilus biogenesis is well characterized, how the usher itself is assembled at the outer membrane is unclear. Here, we report that a rapid response in usher assembly is crucially dependent on the translocation assembly module. We assayed the assembly reaction for a range of ushers and provide mechanistic insight into the β-barrel assembly pathway that enables the rapid deployment of bacterial fimbriae
    corecore