340 research outputs found

    Modelling the impact of referral guideline changes for mild dyskaryosis on colposcopy services in England

    Get PDF
    Objectives: This model examines the effects of changing referral strategies within the established structure of NHS cervical screening driven colposcopy practice. It considers the effects of the new strategy on colposcopy workload, patient waiting times, and associated costs and health benefits. Methods: By postal survey, the current operational strategies of colposcopy services were established by questionnaire with respect to referral practices and management protocols. After first-cut piloting, and utilising published and original research, a Markovian model was constructed, and the impact of the new strategy was determined on colposcopy workload and patient waiting times for three hypothetical clinic types. Expected costs and benefits of the new policy were assessed through the adaptation of a previous ScHARR cervical screening model. Results: Clinic workload is expected to increase by between 21% and 35% within three years of the policy change, depending on clinic efficiency in other areas; the majority of this impact would be seen within the first year. It is predicted that particularly inefficient clinics would struggle to meet the existing waiting time requirements for women referred with low-grade disease, owing to the increased level of workload seen throughout the patient pathway as a result of the implementation of the new policy. The impact of the new policy can, however, be mitigated through improving the efficiency of existing clinics, by altering policies relating to surveillance of low grade disease, post-treatment follow-up, treatment policy (whether or not treatment is performed at the initial colposcopy visit), and through adherence to national guidelines. A cost-effectiveness analysis using the ScHARR liquid-based cytology model suggests that the policy change is likely to be have a cost per quality-adjusted lifeyear gained of between £1,400 and £5,500 per quality-adjusted life-year gained (excluding the costs of follow-up), which would be deemed acceptable to organisations such as the National Institute for Health and Clinical Excellence

    A Projective C*-Algebra Related to K-Theory

    Full text link
    The C*-algebra qC is the smallest of the C*-algebras qA introduced by Cuntz in the context of KK-theory. An important property of qC is the natural isomorphism of K0 of D with classes of homomorphism from qC to matrix algebras over D. Our main result concerns the exponential (boundary) map from K0 of a quotient B to K1 of an ideal I. We show if a K0 element is realized as a homomorphism from qC to B then its boundary is realized as a unitary in the unitization of I. The picture we obtain of the exponential map is based on a projective C*-algebra P that is universal for a set of relations slightly weaker than the relations that define qC. A new, shorter proof of the semiprojectivity of qC is described. Smoothing questions related the relations for qC are addressed.Comment: 11 pages. Added a result about the boundary map in K-theor

    Reflexivity and direct sums

    Get PDF

    Individual Differences in Notetaking, Summarization, and Learning from Lectures

    Get PDF
    This study investigated working memory, verbal ability, and prior knowledge as predictors of the quality of: (a) students' notes taken during a lecture; (b) summaries of the lecture written during a review period; and (c) recall of the lecture content. The usefulness of taking notes was considered in terms of quality of summarization and recall of the lecture material for three groups of students who: (a) listened to the lecture, took notes, and reviewed those notes; (b) listened to the lecture and reviewed a set of provided notes; or (c) listened to the lecture, took notes, and then reviewed a set of provided notes. Results indicated that students with higher working memory benefit more from listening to the lecture than listening and taking notes. However, the quality of summaries written was a more powerful predictor of performance than the individual differences students' brought to the task. This study extends previous studies by integrating summarization and lecture learning research and providing new insight into the role of notetaking and its relationship to working memory.La mémoire de travail, l'habileté verbale et les connaissances préalables ont été étudiées pour leur valeur prédictive de la qualité: (a) des notes que prenaient les étudiants pendant le cours; (b) des résumés de cours rédigés pendant une période de révision; et (c) du rappel du contenu de cours. L'utilité de la prise de notes a été évaluée d'après la qualité des résumés et le rappel du contenu de cours chez trois groupes d'étudiants qui: (a) écoutaient le cours, prenaient des notes et les révisaient; (b) écoutaient le cours et révisaient des notes qu 'on leur fournissait; ou (c) écoutaient le cours, prenaient des notes et révisaient ensuite des notes qu'on leur fournissait. Les résultats indiquent que, pour les étudiants qui ont une plus grande mémoire de travail, il est plus profitable de tout simplement écouter le cours que d'écouter et de prendre des notes. Cependant, la qualité des résumés s'est avérée avoir une meilleure valeur prédictive de la performance que le sont les différences individuelles qui se manifestent pendant l'apprentissage. Cette étude contribue aux précédentes en intégrant la recherche sur le résumé et l'apprentissage qui a lieu pendant les cours, ainsi qu'en fournissant de nouvelles idées sur le rôle de la prise de notes et son lien avec la mémoire de travail

    It's all in the eyes: subcortical and cortical activation during grotesqueness perception in autism

    Get PDF
    Atypical face processing plays a key role in social interaction difficulties encountered by individuals with autism. In the current fMRI study, the Thatcher illusion was used to investigate several aspects of face processing in 20 young adults with high-functioning autism spectrum disorder (ASD) and 20 matched neurotypical controls. “Thatcherized” stimuli were modified at either the eyes or the mouth and participants discriminated between pairs of faces while cued to attend to either of these features in upright and inverted orientation. Behavioral data confirmed sensitivity to the illusion and intact configural processing in ASD. Directing attention towards the eyes vs. the mouth in upright faces in ASD led to (1) improved discrimination accuracy; (2) increased activation in areas involved in social and emotional processing; (3) increased activation in subcortical face-processing areas. Our findings show that when explicitly cued to attend to the eyes, activation of cortical areas involved in face processing, including its social and emotional aspects, can be enhanced in autism. This suggests that impairments in face processing in autism may be caused by a deficit in social attention, and that giving specific cues to attend to the eye-region when performing behavioral therapies aimed at improving social skills may result in a better outcome

    Almost Commuting Matrices, Localized Wannier Functions, and the Quantum Hall Effect

    Full text link
    For models of non-interacting fermions moving within sites arranged on a surface in three dimensional space, there can be obstructions to finding localized Wannier functions. We show that such obstructions are KK-theoretic obstructions to approximating almost commuting, complex-valued matrices by commuting matrices, and we demonstrate numerically the presence of this obstruction for a lattice model of the quantum Hall effect in a spherical geometry. The numerical calculation of the obstruction is straightforward, and does not require translational invariance or introducing a flux torus. We further show that there is a Z2Z_2 index obstruction to approximating almost commuting self-dual matrices by exactly commuting self-dual matrices, and present additional conjectures regarding the approximation of almost commuting real and self-dual matrices by exactly commuting real and self-dual matrices. The motivation for considering this problem is the case of physical systems with additional antiunitary symmetries such as time reversal or particle-hole conjugation. Finally, in the case of the sphere--mathematically speaking three almost commuting Hermitians whose sum of square is near the identity--we give the first quantitative result showing this index is the only obstruction to finding commuting approximations. We review the known non-quantitative results for the torus.Comment: 35 pages, 2 figure

    A Framework for Exploring the Impact of Tutor Practices on Learner Self-regulation in Online Environments

    Get PDF
    There is increasing interest in the conceptualization of Self-Regulated learning (SRL) as a dynamic process which unfolds over the course of a learning activity. This is partly because this conceptualization could potentially be operationalized and used as the basis for AI and analytics tools which monitor and scaffold SRL in real-time. However, while there is an abundance of research on theories of SRL, little research explicitly reviews and operationalizes such theoretical considerations. Work is needed to develop frameworks for the practical applications of fundamental SRL theories, helping researchers move from conceptual considerations to operationalization in real world settings. In this paper, we propose a theoretically grounded framework for investigating SRL in the context of online tutoring for upper primary school learners. SRL is interpreted as a social learning construct, and the framework proposed is designed to investigate the influence of tutor practices on the development of learners’ SRL. We present the results of a pilot study that explored the applicability of the framework

    The impact of cognitive load on processing efficiency and performance effectiveness in anxiety: evidence from event-related potentials and pupillary responses

    Get PDF
    Anxiety has been associated with poor attentional control, as reflected in lowered performance on experimental measures of executive attention and inhibitory control. Recent conceptualisations of anxiety propose that individuals who report elevated anxiety symptoms worry about performance and will exert greater cognitive effort to complete tasks well, particularly when cognitive demands are high. Across two experiments, we examined the effect of anxiety on task performance and across two load conditions using (1) measures of inhibitory control (behavioural reaction times and eye-movement responses) and (2) task effort with pupillary and electrocortical markers of effort (CNV) and inhibitory control (N2). Experiment 1 used an oculomotor-delayed-response task that manipulated load by increasing delay duration to create a high load, relative to a low load, condition. Experiment 2 used a Go/No-Go task and load was manipulated by decreasing the No-Go probabilities (i.e., 20% No-Go in the high load condition and 50% No-Go in the low load condition). Experiment 1 showed individuals with high (vs. low) anxiety made more antisaccade errors across load conditions, and made more effort during the high load condition, as evidenced by greater frontal CNV and increased pupillary responses. In Experiment 2, individuals with high anxiety showed increased effort (irrespective of cognitive load), as characterised by larger pupillary responses. In addition, N2 amplitudes were sensitive to load only in individuals with low anxiety. Evidence of reduced performance effectiveness and efficiency across electrophysiological, pupillary, and oculomotor systems in anxiety provides some support for neurocognitive models of frontocortical attentional dysfunction in anxiety

    Spaced Retrieval Practice: Can Restudying Trump Retrieval?

    Get PDF
    We investigated spaced retrieval and restudying in 3 preregistered, online experiments. In all experiments, participants studied 40 Swahili–English word pair translations during an initial study phase, restudied intact pairs or attempted to retrieve the English words to Swahili cues twice in three spaced practice sessions, and then completed a final cued-recall test. All 5 sessions were separated by 2 days. In Experiment 1, we manipulated the response format during retrieval (covert vs. overt) and the test list structure (blocked vs. intermixed covert/overt retrieval trials). A memory rating was required on all trials (retrieval: “Was your answer correct?”; restudy: “Would you have remembered the correct translation?”). Response format had no effect on recall, but surprisingly, final test performance for restudied items exceeded both the overt and covert retrieval conditions. In Experiment 2, we manipulated the requirement to make a memory rating. If a memory rating was required, final test restudy performance exceeded retrieval performance, replicating Experiment 1. However, the pattern was descriptively reversed if no rating was required. In Experiment 3, the memory rating was removed altogether, and we examined recall performance for items restudied versus retrieved once, twice, or thrice. Performance improved with practice, and retrieval performance exceeded restudy performance in all conditions. The reversal of the typical retrieval practice effect observed in Experiments 1 and 2 is discussed in terms of theories of reactivity of memory judgments
    corecore