1,921 research outputs found

    Ecological validity of a simplified version of the multiple errands shopping test

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    Shallice and Burgess (1991) reported the utility of the Multiple Errands Test (MET) in discriminating executive deficits in three frontal lobe patients with preserved high IQ, who were otherwise unimpaired on tests of executive function. The aim of this study was to ascertain the value of a simplified version of the MET (MET-SV) for use with the range of people more routinely encountered in clinical practice. Main findings were as follows: 1) The test discriminated well between neurological patients and controls, and the group effects remained when the difference in current general cognitive functions (WAIS-R FSIQ) was taken into account. 2) The best predictors of performance in the healthy control group (n = 46) were age and the number of times participants asked for help (with more requests associated with poorer performance). 3) In the neurological group, two clear patterns of failure emerged, with performance either characterized by rule breaking or failure to achieve tasks. These two patterns were associated with different dysexecutive symptoms in everyday life. 4) The patients not only made more errors than controls, but also different ones. A scoring method that took this into account markedly increased test sensitivity. 5) Many patients passed traditional tests of executive frontal lobe function but still failed the MET-SV This pattern was strongly associated with observed dysexecutive symptoms in everyday life. The results demonstrate the clinical utility of the test, and suggest that there are two common and independent sources of failure on multitasking tests in a general neurological population: memory dysfunction, and initiation problems

    Pruning Fruit Trees

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    Beyond Average: Contemporary statistical techniques for analysing student evaluations of teaching

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    © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Student evaluations of teaching (SETs) have been used to evaluate higher education teaching performance for decades. Reporting SET results often involves the extraction of an average for some set of course metrics, which facilitates the comparison of teaching teams across different organisational units. Here, we draw attention to ongoing problems with the naive application of this approach. Firstly, a specific average value may arise from data that demonstrates very different patterns of student satisfaction. Furthermore, the use of distance measures (e.g. an average) for ordinal data can be contested, and finally, issues of multiplicity increasingly plague approaches using hypothesis testing. It is time to advance the methodology of the field. We demonstrate how multinomial distributions and hierarchical Bayesian methods can be used to contextualise the SET scores of a course to different organisational units and student cohorts, and then show how this approach can be used to extract sensible information about how a distribution is changing

    Transformation of Epichloë typhina by electroporation of conidia

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    <p>Abstract</p> <p>Background</p> <p>Choke, caused by the endophytic fungus <it>Epichloë typhina</it>, is an important disease affecting orchardgrass (<it>Dactylis glomerata </it>L.) seed production in the Willamette Valley. Little is known concerning the conditions necessary for successful infection of orchardgrass by <it>E. typhina</it>. Detection of <it>E. typhina </it>in plants early in the disease cycle can be difficult due to the sparse distribution of hyphae in the plant. Therefore, a sensitive method to detect fungal infection in plants would provide an invaluable tool for elucidating the conditions for establishment of infection in orchardgrass. Utilization of a marker gene, such as the green fluorescent protein (GFP), transformed into <it>Epichloë </it>will facilitate characterization of the initial stages of infection and establishment of the fungus in plants.</p> <p>Findings</p> <p>We have developed a rapid, efficient, and reproducible transformation method using electroporation of germinating <it>Epichloë </it>conidia isolated from infected plants.</p> <p>Conclusions</p> <p>The GFP labelled <it>E. typhina </it>provides a valuable molecular tool to researchers studying conditions and mechanisms involved in the establishment of choke disease in orchardgrass.</p

    The case for the development and use of "ecologically valid" measures of executive function in experimental and clinical neuropsychology

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    This article considers the scientific process whereby new and better clinical tests of executive function might be developed, and what form they might take. We argue that many of the traditional tests of executive function most commonly in use (e.g., the Wisconsin Card Sorting Test; Stroop) are adaptations of procedures that emerged almost coincidentally from conceptual and experimental frameworks far removed from those currently in favour, and that the prolongation of their use has been encouraged by a sustained period of concentration on “construct-driven” experimentation in neuropsychology. This resulted from the special theoretical demands made by the field of executive function, but was not a necessary consequence, and may not even have been a useful one. Whilst useful, these tests may not therefore be optimal for their purpose. We consider as an alternative approach a function-led development programme which in principle could yield tasks better suited to the concerns of the clinician because of the transparency afforded by increased “representativeness” and “generalisability.” We further argue that the requirement of such a programme to represent the interaction between the individual and situational context might also provide useful constraints for purely experimental investigations. We provide an example of such a programme with reference to the Multiple Errands and Six Element tests
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