72 research outputs found

    Problem Identification and Task Engagement Using the LIBRE Problem Solving Tool: A Case Study of Three Bilingual Teacher Candidates

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    Bilingual Latino students engage multiple languages, cultures and environments as they pursue educational and professional goals. For this underrepresented group, pursuing a post-secondary degree is a “lucha” (fight) to negotiate the complex interplay of historical, educational, and cultural variables and achieve academic success. Because Bilingual Latino teacher success is incumbent upon successfully negotiating and overcoming linguistic, cultural and educational challenges, examination of problem solving and goal setting is necessary to provide insight into the types of barriers and facilitators that this group experiences and the ways in which they overcome obstacles. An in-depth case study of three bilingual teacher candidates illustrates the use of the LIBRE problem-solving tool as a culturally responsive activity involving a sequence of problem identification, analysis, solution generation, and evaluation to facilitate problem resolution. The case studies examined herein illuminate self-reported social-cultural contextual challenges, solutions, goals, and engagement through explicit problem solving and shows the primacy of familia and cultura in these women’s lives, problem-solving, and decision making. Implications for teacher educators and bilingual Latino teacher candidates are discussed

    Molecular dynamics simulations and coupled nucleotide substitution experiments indicate the nature of A·A base pairing and a putative structure of the coralyne-induced homo-adenine duplex

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    Coralyne is an alkaloid drug that binds homo-adenine DNA (and RNA) oligonucleotides more tightly than it does Watson–Crick DNA. Hud’s laboratory has shown that poly(dA) in the presence of coralyne forms an anti-parallel duplex, however attempts to determine the structure by NMR spectroscopy and X-ray crystallography have been unsuccessful. Assuming adenine–adenine hydrogen bonding between the two poly(dA) strands, we constructed 40 hypothetical homo-(dA) anti-parallel duplexes and docked coralyne into the six most favorable duplex structures. The two most stable structures had trans glycosidic bonds, but distinct pairing geometries, i.e. either Watson–Crick Hoogsteen (transWH) or Watson–Crick Watson–Crick (transWW) with stability of transWH > transWW. To narrow down the possibilities, 7-deaza adenine base substitutions (dA→7) were engineered into homo-(dA) sequences. These substitutions significantly reduced the thermal stability of the coralyne-induced homo-(dA) structure. These experiments strongly suggest the involvement of N7 in the coralyne-induced A·A base pairs. Moreover, due to the differential effect on melting as a function of the location of the dA→7 mutations, these results are consistent with the N1–N7 base pairing of the transWH pairs. Together, the simulation and base substitution experiments predict that the coralyne-induced homo-(dA) duplex structure adopts the transWH geometry

    Seeding Structures for a Community of Practice Focused on Transient Ischemic Attack (TIA): Implementing Across Disciplines and Waves

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    Background: The Community of Practice (CoP) model represents one approach to address knowledge management to support effective implementation of best practices. Objective: We sought to identify CoP developmental strategies within the context of a national quality improvement project focused on improving the quality for patients receiving acute transient ischemic attack (TIA) care. Design: Stepped wedge trial. Participants: Multidisciplinary staff at six Veterans Affairs medical facilities. Interventions: To encourage site implementation of a multi-component quality improvement intervention, the trial included strategies to improve the development of a CoP: site kickoff meetings, CoP conference calls, and an interactive website (the "Hub"). Approach: Mixed-methods evaluation included data collected through a CoP attendance log; semi-structured interviews with site participants at 6 months (n = 32) and 12 months (n = 30), and CoP call facilitators (n = 2); and 22 CoP call debriefings. Key results: The critical seeding structures that supported the cultivation of the CoP were the kickoffs which fostered relationships (key to the community element of CoPs) and provided the evidence base relevant to TIA care (key to the domain element of CoPs). The Hub provided the forum for sharing quality improvement plans and other tools which were further highlighted during the CoP calls (key to the practice element of CoPs). CoP calls were curated to create a positive context around participants' work by recognizing team successes. In addition to improving care at their local facilities, the community created a shared set of tools which built on their collective knowledge and could be shared within and outside the group. Conclusions: The PREVENT CoP advanced the mission of the learning healthcare system by successfully providing a forum for shared learning. The CoP was grown through seeding structures that included kickoffs, CoP calls, and the Hub. A CoP expands upon the learning collaborative implementation strategy as an effective implementation practice

    Dimensionality of Carbon Nanomaterials Determines the Binding and Dynamics of Amyloidogenic Peptides: Multiscale Theoretical Simulations

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    Experimental studies have demonstrated that nanoparticles can affect the rate of protein self-assembly, possibly interfering with the development of protein misfolding diseases such as Alzheimer's, Parkinson's and prion disease caused by aggregation and fibril formation of amyloid-prone proteins. We employ classical molecular dynamics simulations and large-scale density functional theory calculations to investigate the effects of nanomaterials on the structure, dynamics and binding of an amyloidogenic peptide apoC-II(60-70). We show that the binding affinity of this peptide to carbonaceous nanomaterials such as C60, nanotubes and graphene decreases with increasing nanoparticle curvature. Strong binding is facilitated by the large contact area available for π-stacking between the aromatic residues of the peptide and the extended surfaces of graphene and the nanotube. The highly curved fullerene surface exhibits reduced efficiency for π-stacking but promotes increased peptide dynamics. We postulate that the increase in conformational dynamics of the amyloid peptide can be unfavorable for the formation of fibril competent structures. In contrast, extended fibril forming peptide conformations are promoted by the nanotube and graphene surfaces which can provide a template for fibril-growth

    Acceptability of a complex team-based quality improvement intervention for transient ischemic attack: a mixed-methods study

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    Background: The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurologic Symptoms (PREVENT) program was a complex quality improvement (QI) intervention targeting transient ischemic attack (TIA) evidence-based care. The aim of this study was to evaluate program acceptability among the QI teams and factors associated with degrees of acceptability. Methods: QI teams from six Veterans Administration facilities participated in active implementation for a one-year period. We employed a mixed methods study to evaluate program acceptability. Multiple data sources were collected over implementation phases and triangulated for this evaluation. First, we conducted 30 onsite, semi-structured interviews during active implementation with 35 participants at 6 months; 27 interviews with 28 participants at 12 months; and 19 participants during program sustainment. Second, we conducted debriefing meetings after onsite visits and monthly virtual collaborative calls. All interviews and debriefings were audiotaped, transcribed, and de-identified. De-identified files were qualitatively coded and analyzed for common themes and acceptability patterns. We conducted mixed-methods matrix analyses comparing acceptability by satisfaction ratings and by the Theoretical Framework of Acceptability (TFA). Results: Overall, the QI teams reported the PREVENT program was acceptable. The clinical champions reported high acceptability of the PREVENT program. At pre-implementation phase, reviewing quality data, team brainstorming solutions and development of action plans were rated as most useful during the team kickoff meetings. Program acceptability perceptions varied over time across active implementation and after teams accomplished actions plans and moved into sustainment. We observed team acceptability growth over a year of active implementation in concert with the QI team's self-efficacy to improve quality of care. Guided by the TFA, the QI teams' acceptability was represented by the respective seven components of the multifaceted acceptability construct. Conclusions: Program acceptability varied by time, by champion role on QI team, by team self-efficacy, and by perceived effectiveness to improve quality of care aligned with the TFA. A complex quality improvement program that fostered flexibility in local adaptation and supported users with access to data, resources, and implementation strategies was deemed acceptable and appropriate by front-line clinicians implementing practice changes in a large, national healthcare organization

    Exocyclic amino groups of flanking guanines govern sequence-dependent adduct conformations and local structural distortions for minor groove-aligned benzo[a]pyrenyl-guanine lesions in a GG mutation hotspot context

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    The environmental carcinogen benzo[a]pyrene (BP) is metabolized to reactive diol epoxides that bind to cellular DNA by predominantly forming N(2)-guanine adducts (G*). Mutation hotspots for these adducts are frequently found in 5′- ··· GG ··· dinucleotide sequences, but their origins are poorly understood. Here we used high resolution NMR and molecular dynamics simulations to investigate differences in G* adduct conformations in 5′- ··· CG*GC ··· and 5′- ··· CGG* C··· sequence contexts in otherwise identical 12-mer duplexes. The BP rings are positioned 5′ along the modified strand in the minor groove in both cases. However, subtle orientational differences cause strong distinctions in structural distortions of the DNA duplexes, because the exocyclic amino groups of flanking guanines on both strands compete for space with the BP rings in the minor groove, acting as guideposts for placement of the BP. In the 5′- ··· CGG* C ··· case, the 5′-flanking G · C base pair is severely untwisted, concomitant with a bend deduced from electrophoretic mobility. In the 5′- ··· CG*GC ··· context, there is no untwisting, but there is significant destabilization of the 5′-flanking Watson–Crick base pair. The minor groove width opens near the lesion in both cases, but more for 5′- ··· CGG*C···. Differential sequence-dependent removal rates of this lesion result and may contribute to the mutation hotspot phenomenon

    Central venous catheter use in severe malaria: time to reconsider the World Health Organization guidelines?

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    <p>Abstract</p> <p>Background</p> <p>To optimize the fluid status of adult patients with severe malaria, World Health Organization (WHO) guidelines recommend the insertion of a central venous catheter (CVC) and a target central venous pressure (CVP) of 0-5 cmH<sub>2</sub>O. However there are few data from clinical trials to support this recommendation.</p> <p>Methods</p> <p>Twenty-eight adult Indian and Bangladeshi patients admitted to the intensive care unit with severe <it>falciparum </it>malaria were enrolled in the study. All patients had a CVC inserted and had regular CVP measurements recorded. The CVP measurements were compared with markers of disease severity, clinical endpoints and volumetric measures derived from transpulmonary thermodilution.</p> <p>Results</p> <p>There was no correlation between the admission CVP and patient outcome (p = 0.67) or disease severity (p = 0.33). There was no correlation between the baseline CVP and the concomitant extravascular lung water (p = 0.62), global end diastolic volume (p = 0.88) or cardiac index (p = 0.44). There was no correlation between the baseline CVP and the likelihood of a patient being fluid responsive (p = 0.37). On the occasions when the CVP was in the WHO target range patients were usually hypovolaemic and often had pulmonary oedema by volumetric measures. Seven of 28 patients suffered a complication of the CVC insertion, although none were fatal.</p> <p>Conclusion</p> <p>The WHO recommendation for the routine insertion of a CVC, and the maintenance of a CVP of 0-5 cmH<sub>2</sub>O in adults with severe malaria, should be reconsidered.</p

    A connectome and analysis of the adult Drosophila central brain.

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    The neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets. We define cell types, refine computational compartments, and provide an exhaustive atlas of cell examples and types, many of them novel. We provide detailed circuits consisting of neurons and their chemical synapses for most of the central brain. We make the data public and simplify access, reducing the effort needed to answer circuit questions, and provide procedures linking the neurons defined by our analysis with genetic reagents. Biologically, we examine distributions of connection strengths, neural motifs on different scales, electrical consequences of compartmentalization, and evidence that maximizing packing density is an important criterion in the evolution of the fly's brain

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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