140 research outputs found
The Future of Charge Card Networks
The general-purpose charge card is now ubiquitous and largely taken for granted. Annual charge card volume exceeds $5 trillion worldwide. Within the United States, nearly one billion cards are in use (about eight per household), and more than two billion worldwide. But charge cards, or more specifically, the cooperative networks that serve the largest card systems, Visa and MasterCard, are under legal attack through multiple lawsuits and under regulatory challenge in other countries. We trace in this essay multiple possible future 'scenarios'. This focus on possible futures distinguishes our work from many earlier studies of this subject.
The PAMP c-di-AMP Is Essential for Listeria monocytogenes Growth in Rich but Not Minimal Media due to a Toxic Increase in (p)ppGpp
SummaryCyclic di-adenosine monophosphate (c-di-AMP) is a widely distributed second messenger that appears to be essential in multiple bacterial species, including the Gram-positive facultative intracellular pathogen Listeria monocytogenes. In this study, the only L. monocytogenes diadenylate cyclase gene, dacA, was deleted using a Cre-lox system activated during infection of cultured macrophages. All ÎdacA strains recovered from infected cells harbored one or more suppressor mutations that allowed growth in the absence of c-di-AMP. Suppressor mutations in the synthase domain of the bi-functional (p)ppGpp synthase/hydrolase led to reduced (p)ppGpp levels. A genetic assay confirmed that dacA was essential in wild-type but not strains lacking all three (p)ppGpp synthases. Further genetic analysis suggested that c-di-AMP was essential because accumulated (p)ppGpp altered GTP concentrations, thereby inactivating the pleiotropic transcriptional regulator CodY. We propose that c-di-AMP is conditionally essential for metabolic changes that occur in growth in rich medium and host cells but not minimal medium
Outcome measures in post-stroke arm rehabilitation trials: do existing measures capture outcomes that are important to stroke survivors, carers, and clinicians?
Objective:
We sought to (1) identify the outcome measures currently used across stroke arm rehabilitation randomized trials, (2) identify and compare outcomes important to stroke survivors, carers and clinicians and (3) describe where existing research outcome measures capture outcomes that matter the most to stroke survivors, carers and clinicians and where there may be discrepancies.
Methods:
First, we systematically identified and extracted data on outcome measures used in trials within a Cochrane overview of arm rehabilitation interventions. Second, we conducted 16 focus groups with stroke survivors, carers and clinicians using nominal group technique, supplemented with eight semi-structured interviews, to identify these stakeholdersâ most important outcomes following post-stroke arm impairment. Finally, we described the constructs of each outcome measure and indicated where stakeholdersâ important outcomes were captured by each measure.
Results:
We extracted 144 outcome measures from 243 post-stroke arm rehabilitation trials. The Fugl-Meyer Assessment Upper Extremity section (used in 79/243 trials; 33%), Action Research Arm Test (56/243; 23%), and modified Ashworth Scale (53/243; 22%) were most frequently used. Stroke survivors (nâ=â43), carers (nâ=â10) and clinicians (nâ=â58) identified 66 unique, important outcomes related to arm impairment following stroke. Between one and three outcomes considered important by the stakeholders were captured by the three most commonly used assessments in research.
Conclusion:
Post-stroke arm rehabilitation research would benefit from a reduction in the number of outcome measures currently used, and better alignment between what is measured and what is important to stroke survivors, carers and clinicians
The purpose of rating quality of evidence differs in an overview, as compared to guidelines or recommendations
No abstract available
An algorithm was developed to assign GRADE levels of evidence to comparisons within systematic reviews
Objectives:
One recommended use of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is supporting quality assessment of evidence of comparisons included within a Cochrane overview of reviews. Within our overview, reviewers found that current GRADE guidance was insufficient to make reliable and consistent judgments. To support our ratings, we developed an algorithm to grade quality of evidence using concrete rules.
Methods:
Using a pragmatic, exploratory approach, we explored the challenges of applying GRADE levels of evidence and developed an algorithm to applying GRADE levels of evidence in a consistent and transparent approach. Our methods involved application of algorithms and formulas to samples of reviews, expert panel discussion, and iterative refinement and revision.
Results:
The developed algorithm incorporated four key criteria: number of participants, risk of bias of trials, heterogeneity, and methodological quality of the review. A formula for applying GRADE level of evidence from the number of downgrades assigned by the algorithm was agreed.
Conclusion:
Our algorithm which assigns GRADE levels of evidence using a set of concrete rules was successfully applied within our Cochrane overview. We propose that this methodological approach has implications for assessment of quality of evidence within future evidence syntheses
A qualitative exploration of the effect of visual field loss on daily life in home-dwelling stroke survivors
Objective: To explore the effect of visual field loss on the daily life of community-dwelling stroke survivors. Design: A qualitative interview study. Participants: Adult stroke survivors with visual field loss of at least sixâmonthsâ duration. Methods: Semi-structured interviews were conducted with a non-purposive sample of 12 stroke survivors in their own homes. These were recorded, transcribed verbatim and analyzed with the framework method, using an inductive approach. Results: Two key analytical themes emerged. âPerception, experience and knowledgeâ describes participantâs conflicted experience of having knowledge of their impaired vision but lacking perception of that visual field loss and operating under the assumption that they were viewing an intact visual scene when engaged in activities. Inability to recognize and deal with visual difficulties, and experiencing the consequences, contributed to their fear and loss of self-confidence. âAvoidance and adaptationâ were two typologies of participant response to visual field loss. Initially, all participants consciously avoided activities. Some later adapted to vision loss using self-directed head and eye scanning techniques. Conclusions: Visual field loss has a marked impact on stroke survivors. Stroke survivors lack perception of their visual loss in everyday life, resulting in fear and loss of confidence. Activity avoidance is a common response, but in some, it is replaced by self-initiated adaptive techniques
Editorial: From Pedagogic Research to Embedded E-Learning
This Special Issue of Reflecting Education arises from the work of the PREEL project (From Pedagogic Research to Embedded e-Learning) at the Institute of Education from 2006-2008. This project was one of nine HEA/JISC (Higher Education Academy and Joint Information Systems Committee) Pilot Pathfinder Projects and followed on from our involvement in the Pilot Benchmarking of e-Learning Programme. In the benchmarking exercise we identified a lack of coordination between research and practice in e-learning at the IoE as one of our crucial weaknesses, and so our Pilot Pathfinder project concentrated on this theme of building links between e-learning research and practice
Visual Function Questionnaire as an outcome measure for homonymous hemianopia: subscales and supplementary questions, analysis from the VISION trial
Background: We conduct supplementary analyses of the NEI VFQ-25 data to evaluate where changes occurred within subscales of the NEI VFQ-25 leading to change in the composite scores between the three treatment arms, and evaluate the NEI VFQ-25 with and without the Neuro 10 supplement. Methods: A prospective, multicentre, parallel, single-blind, three-arm RCT of fourteen UK acute stroke units was conducted. Stroke survivors with homonymous hemianopia were recruited. Interventions included: Fresnel prisms for minimum 2âh, 5 days/week over 6-weeks (Arm a), Visual search training for minimum 30âmin, 5 days/week over 6-weeks (Arm b) and standard care-information only (Arm c). Primary and secondary outcomes (including NEI VFQ-25 data) were measured at baseline, 6, 12 and 26 weeks after randomisation. Results: Eighty seven patients were recruited (69% male; mean age (SD) equal to 69 (12) years). At 26 weeks, outcomes for 24, 24 and 22 patients, respectively, were compared to baseline. NEI VFQ-25 (with and without Neuro 10) responses improved from baseline to 26 weeks with visual search training compared to Fresnel prisms and standard care. In subscale analysis, the most impacted across all treatment arms was âdrivingâ whilst the least impacted were âcolour visionâ and âocular painâ. Conclusions: Composite scores differed systematically for the NEI VFQ-25 (Neuro 10) versus NEI VFQ-25 at all time points. For subscale scores, descriptive statistics suggest clinically relevant improvement in distance activities and vision-specific dependency subscales for NEI VFQ-25 scores in the visual search treatment arm. Trial Registration: Current Controlled Trials ISRCTN05956042
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