1,853 research outputs found

    Becoming Peer Tutors of Writing: Identity Development as a Mode of Preparation

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    Primary and secondary teachers of English are typically the subjects of research centered on writing teacher education. However, at the college level writing teacher education also includes individuals who instruct and support undergraduate writing instruction, and who do not always identify as writing teachers, such as graduate teaching assistants and peer writing tutors writing. Writing program administrators responsible for preparing TAs and tutors can benefit from the results of relevant research from the K-12 discourse community to improve their preparation programs. For example, research in primary and secondary teacher education programs indicates that when preparatory sessions highlight the concept of teacher identity in the preparation of K-12 teacher candidates, then the teacher candidates have higher levels of teacher efficacy, job satisfaction, and retention in the field (Danielewicz; Alsup; McKinney et al.). This article shares the results of a case study that examined how peer tutors of writing developed their identities as tutors in their preparation programs, using the concept of teacher identity as a theoretical framework. The resulting themes are presented as a heuristic of teacher identity characteristics along a novice-to-expert spectrum focusing on four characteristics: content knowledge and behaviors; flexibility in theory and practice, membership in a peer community, and engagement in reflective practices

    A Role for Intraflagellar Transport Proteins in Mitosis: A Dissertation

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    Disruption of cilia proteins results in a range of disorders called ciliopathies. However, the mechanism by which cilia dysfunction contributes to disease is not well understood. Intraflagellar transport (IFT) proteins are required for ciliogenesis. They carry ciliary cargo along the microtubule axoneme while riding microtubule motors. Interestingly, IFT proteins localize to spindle poles in non-ciliated, mitotic cells, suggesting a mitotic function for IFT proteins. Based on their role in cilia, we hypothesized that IFT proteins regulate microtubule-based transport during mitotic spindle assembly. Biochemical investigation revealed that in mitotic cells IFT88, IFT57, IFT52, and IFT20 interact with dynein1, a microtubule motor required for spindle pole maturation. Furthermore, IFT88 co-localizes with dynein1 and its mitotic cargo during spindle assembly, suggesting a role for IFT88 in regulating dynein-mediated transport to spindle poles. Based on these results we analyzed spindle poles after IFT protein depletion and found that IFT88 depletion disrupted EB1, Îł-tubulin, and astral microtubule arrays at spindle poles. Unlike IFT88, depletion of IFT57, IFT52, or IFT20 did not disrupt spindle poles. Strikingly, the simultaneous depletion of IFT88 and IFT20 rescued the spindle pole disruption caused by IFT88 depletion alone, suggesting a model in which IFT88 negatively regulates IFT20, and IFT20 negatively regulates microtubulebased transport during mitosis. Our work demonstrates for the first time that IFT proteins function with dynein1 in mitosis, and it also raises the important possibility that mitotic defects caused by IFT protein disruption could contribute to the phenotypes associated with ciliopathies

    Kronic hysteria: Exploring the intersection between Australian synthetic cannabis legislation, the media, and drug-related harm

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    Background Having first appeared in Europe, synthetic cannabis emerged as a drug of concern in Australia during 2011. Kronic is the most well-known brand of synthetic cannabis in Australia and received significant media attention. Policy responses were reactive and piecemeal between state and federal governments. In this paper we explore the relationship between media reports, policy responses, and drug-related harm. Methods Google search engine applications were used to produce time–trend graphs detailing the volume of media stories being published online about synthetic cannabis and Kronic, and also the amount of traffic searching for these terms. A discursive analysis was then conducted on those media reports that were identified by Google as ‘key stories’. The timing of related media stories was also compared with self-reported awareness and month of first use, using previously unpublished data from a purposive sample of Australian synthetic cannabis users. Results Between April and June 2011, mentions of Kronic in the media increased. The number of media stories published online connected strongly with Google searches for the term Kronic. These stories were necessarily framed within dominant discourses that served to construct synthetic cannabis as pathogenic and created a ‘moral panic’. Australian state and federal governments reacted to this moral panic by banning individual synthetic cannabinoid agonists. Manufacturers subsequently released new synthetic blends that they claimed contained new unscheduled chemicals. Conclusion Policies implemented within in the context of ‘moral panic’, while well-intended, can result in increased awareness of the banned product and the use of new yet-to-be-scheduled drugs with unknown potential for harm. Consideration of regulatory models should be based on careful examination of the likely intended and unintended consequences. Such deliberation might be limited by the discursive landscape

    Clathrin-mediated endocytosis in AP-2–depleted cells

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    We have used RNA interference to knock down the AP-2 ÎŒ2 subunit and clathrin heavy chain to undetectable levels in HeLaM cells. Clathrin-coated pits associated with the plasma membrane were still present in the AP-2–depleted cells, but they were 12-fold less abundant than in control cells. No clathrin-coated pits or vesicles could be detected in the clathrin-depleted cells, and post-Golgi membrane compartments were swollen. Receptor-mediated endocytosis of transferrin was severely inhibited in both clathrin- and AP-2–depleted cells. Endocytosis of EGF, and of an LDL receptor chimera, were also inhibited in the clathrin-depleted cells; however, both were internalized as efficiently in the AP-2–depleted cells as in control cells. These results indicate that AP-2 is not essential for clathrin-coated vesicle formation at the plasma membrane, but that it is one of several endocytic adaptors required for the uptake of certain cargo proteins including the transferrin receptor. Uptake of the EGF and LDL receptors may be facilitated by alternative adaptors

    Using the forces of hydrodynamic countercurrent chromatography for the study of bacteriophages

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    Bacteriophages (phages) are viruses that target bacteria, with the ability to lyse and kill host bacterial cells. Due to this, they have been of some interest as a therapeutic since their discovery in the early 1900s, but with the recent increase in antibiotic resistance, phages have seen a resurgence in attention. Current methods of isolation and purification of phages can be long and tedious, with caesium chloride concentration gradients the gold standard for purifying a phage fraction. Isolation of novel phages requires centrifugation and ultrafiltration of mixed samples, such as water sources, effluent or faecal samples etc, to prepare phage filtrates for further testing. We propose countercurrent chromatography as a novel and alternative approach to use when studying phages, as a scalable and high-yield method for obtaining phage fractions. However, the full extent of the usefulness and resolution of separation with this technique has not been researched; it requires optimization and ample testing before this can be revealed. Here we present an initial study to determine survivability of two phages, T4 and ϕX174, using only water as a mobile phase in a Spectrum Series 20 HPCCC. Both phages were found to remain active once eluted from the column. Phages do not fully elute from the column and sodium hydroxide is necessary to flush the column between runs to deactivate remaining phages

    Blood eosinophil-guided oral prednisolone for COPD exacerbations in primary care in the UK (STARR2): A non-inferiority, multicentre, double-blind, placebo-controlled, randomised controlled trial

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    Background: Systemic glucocorticoids are recommended for use in chronic obstructive pulmonary disease (COPD) exacerbations; however, there is increased harm associated with their use. We hypothesised that the use of eosinophil biomarker-directed oral prednisolone therapy at the time of an exacerbation of COPD was effective at reducing prednisolone use without affecting adverse outcomes. Methods: The studying acute exacerbations and response (STARR2) study was a multicentre, randomised, double-blind, placebo-controlled trial conducted in 14 primary care practices in the UK. We included adults (aged ≄ 40 years), who were current or former smokers (with at least a 10 pack year smoking history) with a diagnosis of COPD, defined as a post-bronchodilator FEV1/forced vital capacity ratio of less than 0·7 previously recorded by the primary care physician, and a history of at least one exacerbation in the previous 12 months requiring systemic corticosteroids with or without antibiotics. All study staff and participants were masked to study group allocation and to treatment allocation. Participants were randomly assigned (1:1) to blood eosinophil-directed treatment (BET; to receive oral prednisolone 30 mg once daily if eosinophil count was high [ ≄ 2%] or placebo if eosinophil count was low [ \u3c 2%]) or to standard care treatment (ST; to receive prednisolone 30 mg once daily irrespective of the point-of-care eosinophil result). Treatment was prescribed for 14 days and all patients also received antibiotics. The primary outcome was the rate of treatment failure, defined as any need for re-treatment with antibiotics or steroids, hospitalisation for any cause, or death, assessed at 30 days after exacerbation in the modified intention-to-treat population. Participants were eligible for re-randomisation at further exacerbations (with a maximum of four exacerbations per participant). A safety analysis was conducted on all randomly assigned participants. Although designed as a superiority trial, after identification of an error in the randomisation code before data lock the study converted to show non-inferiority. An upper margin of 1·105 for the 95% CI was defined as the non-inferiority margin. This study was registered with EudraCT, 2017-001586-24, and is complete. Findings: Between Nov 6, 2017, and April 30, 2020, 308 participants were recruited from 14 general practices. 144 exacerbations (73 in the BET group and 71 in the ST group) from 93 participants (mean age 70 years [range 46–84] and mean percent predicted FEV1 60·9% [SD 19·4]; 52 [56%] male and 41 [44%] female; ethnicity data was not collected]) were included in the modified intention-to-treat analysis. There were 14 (19%) treatment failures at 30 days post-exacerbation in the BET group and 23 (32%) in the ST group; we found a large non-significant estimated effect between BET and ST (RR 0·60 [95% CI 0·33–1·04]; p=0·070) in reducing treatment failures after a COPD exacerbation. The non-inferiority analysis supported that BET was non-inferior to ST. Frequency of adverse events were similar between the study groups; glycosuria (2/102 [2%] in BET group and 1/101 [1%] in the ST group) and hospital admission for COPD exacerbation (2/102 [2%] in BET group and 1/101 [1%] in the ST group) were the two most common adverse events in both groups. No deaths occurred in the study. Interpretation: Blood eosinophil-directed prednisolone therapy at the time of an acute exacerbation of COPD is non-inferior to standard care and can be used to safely reduce systemic glucocorticoid use in clinical practice. Funding: National Institute for Health and Care Research

    Influence of practice schedules and attention on skill development and retention

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    Focus of attention during dual-tasks and practice schedules are important components of motor skill performance and learning; often studied in isolation. The current study required participants to complete a simple key-pressing task under a blocked or random practice schedule. To manipulate attention, participants reported their finger position (i.e., skill-focused attention) or the pitch of an auditory tone (i.e., extraneous attention) while performing two variations of a dual-task key-pressing task. Analyses were conducted at baseline, 10 min and 24 h after acquisition. The results revealed that participants in a blocked schedule, extraneous focus condition had significantly faster movement times during retention compared to a blocked schedule, skill focus condition. Furthermore, greatest improvements from baseline to immediate and delayed retention were evident for an extraneous attention compared to the skill-focused attention, regardless of practice schedule. A discussion of the unique benefits an extraneous focus of attention may have on the learning process during dual-task conditions is presented

    Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

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    We present detailed observations of ZTF18abukavn (SN2018gep), discovered in high-cadence data from the Zwicky Transient Facility as a rapidly rising (1.4 ± 0.1 mag hr-1) and luminous (Mg,peak = -20 mag) transient. It is spectroscopically classified as a broad-lined stripped-envelope supernova (Ic-BL SN). The high peak luminosity (Lbol ≳ 3 × 1044 erg s-1), the short rise time (trise = 3 days in g band), and the blue colors at peak (g-r ∌ -0.4) all resemble the high-redshift Ic-BL iPTF16asu, as well as several other unclassified fast transients. The early discovery of SN2018gep (within an hour of shock breakout) enabled an intensive spectroscopic campaign, including the highest-temperature (Teff ≳ 40,000 K) spectra of a stripped-envelope SN. A retrospective search revealed luminous (Mg ∌ Mr ≈ mag) emission in the days to weeks before explosion, the first definitive detection of precursor emission for a Ic-BL. We find a limit on the isotropic gamma-ray energy release E Îł,iso \u3c 4.9 × 10 48 erg, a limit on X-ray emission LX \u3c 1040 erg s-1, and a limit on radio emission Îœ LÎœ â‰Č 1037 erg s-1. Taken together, we find that the early (\u3c 10 days) data are best explained by shock breakout in a massive shell of dense circumstellar material (0.02 M⊙) at large radii (3 × 1014 cm) that was ejected in eruptive pre-explosion mass-loss episodes. The late-time (\u3e 10 days) light curve requires an additional energy source, which could be the radioactive decay of Ni-56

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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