54 research outputs found

    Keeping visual-auditory associations in mind: The impact of detail and meaningfulness on crossmodal working memory load

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    Complex objects have been found to take up more visual working memory---as measured by lowered change-detection accuracy with such stimuli---than simple colored shapes (Treisman, 2006; Xu, 2002). While verbal working memory studies have similarly shown reduced apparent capacity for longer words (Baddeley, 2007), other research has demonstrated that features contributing to object categorization and recognizability can help visual working memory capacity (Olsson & Poom, 2005; Alvarez & Cavanagh, 2004). Until very recently, no measures of crossmodal working memory capacity had been proposed, even though crossmodal associations are part of the fabric of learning, from classical conditioning to calculus. The working memory load of a range of complex crossmodal (visual--auditory) objects was measured here in a sequence of experiments adapting classic visual change detection procedures (Vogel et al., 2001). The adapted method involves rapid sequential presentation of objects, each comprising a sound and an image, with a test object appearing after a 1-second delay. Application of this method shed light on the working memory impact of two sources of complexity, featural detail and object meaningfulness. Displaying the test object in a previously unused location---in this case, the center of the screen---resulted in lower change-detection performance compared to placement in its original location. Test location interacted with the role of different image types (gray and colored shapes, drawings, and photos). Image type showed no consistent pattern of influence on working memory capacity when test objects appeared in their original locations; when shown in an alternate location, crossmodal associations involving more-detailed images were more accurately recalled. Independent of test location, more-complex animal sounds provided better crossmodal change detection performance than abstract tones. An association measure showed consistently higher numbers of associations for representational images than abstract ones. Observers\u27 response bias was lower for meaningful images, but their change-detection accuracy did not differ by image meaningfulness. The results obtained with this novel crossmodal working memory measure demonstrate that perceptual detail contributes to effective crossmodal working memory capacity for sounds and for abstract and realistic images

    Gliomatosis cerebri presenting as rapidly progressive dementia and parkinsonism in an elderly woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Dementia is one of the most important neurological disorders in the elderly. Dementia of tumoral origin is rare and parkinsonism of neoplastic origin is unusual. We herein report a case of gliomatosis cerebri, a very rare brain tumor seldom affecting the elderly, which presented as rapidly progressive dementia and parkinsonism.</p> <p>Case presentation</p> <p>An 82-year-old woman very rapidly developed progressive dementia and akineto-rigid parkinsonism. Brain CT scan was normal. Cerebral magnetic resonance imaging (MRI) with gadolinium injection highlighted a diffuse tumor-related infiltration involving both lobes, the putamen, the pallidum, the substantia nigra, and the brainstem, corresponding to the specific description and definition of gliomatosis cerebri.</p> <p>Conclusion</p> <p>This atypical presentation of a gliomatosis cerebri, and the infiltration of the substantia nigra by the tumor, merits attention.</p

    Social Determinants of Smoking in Low- and Middle-Income Countries: Results from the World Health Survey

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    INTRODUCTION: Tobacco smoking is a leading cause of premature death and disability, and over 80% of the world's smokers live in low- or middle-income countries. The objective of this study is to assess demographic and socioeconomic determinants of current smoking in low- and middle-income countries. METHODS: We used data, from the World Health Survey in 48 low-income and middle-income countries, to explore the impact of demographic and socioeconomic factors on the current smoking status of respondents. The data from these surveys provided information on 213,807 respondents aged 18 years or above that were divided into 4 pooled datasets according to their sex and country income group. The overall proportion of current smokers, as well as the proportion by each relevant demographic and socioeconomic determinant, was calculated within each of the pooled datasets, and multivariable logistic regression was used to assess the association between current smoking and these determinants. RESULTS: The odds of smoking were not equal in all demographic or socioeconomic groups. Some factors were fairly stable across the four datasets studied: for example, individuals were more likely to smoke if they had little or no education, regardless of if they were male or female, or lived in a low or a middle income country. Nevertheless, other factors, notably age and wealth, showed a differential effect on smoking by sex or country income level. While women in the low-income country group were twice as likely to smoke if they were in the lowest wealth quintile compared with the highest, the association was absent in the middle-income country group. CONCLUSION: Information on how smoking is distributed among low- or middle-income countries will allow policy makers to tailor future policies, and target the most vulnerable populations

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Crossmodal binding in working memory

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    Visual Thinking with Interactive Diagram

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