3,127 research outputs found

    On the classification of rank two representations of quasiprojective fundamental groups

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    Suppose XX is a smooth quasiprojective variety over \cc and \rho : \pi _1(X,x) \to SL(2,\cc) is a Zariski-dense representation with quasiunipotent monodromy at infinity. Then ρ\rho factors through a map XYX\to Y with YY either a DM-curve or a Shimura modular stack.Comment: minor changes in exposition, citation

    Young children retain fast mapped object labels better than shape, color, and texture words

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    We compared short- and long-term retention of fast mapped color, shape and texture words as well as object labels. In an exposure session, 354 3- and 4-year-old children were shown a set of two familiar and three novel stimuli. One of the novel stimuli was labeled with a new object label, color, shape or texture word. Retention of the mapping between the new word and the novel object or property was measured either five minutes or one week later. After five minutes, retention was significantly above chance in all conditions. However, after one week only the mappings for object labels were retained above chance levels. Our findings suggest that fast mapped object labels are retained long-term better than color, shape and texture words. The results also highlight the importance of comparing short- and long-term retention when studying children’s word learning

    Notes and Discussion Piece: Status of the Topeka Shiner in Iowa

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    The Topeka shiner Notropis topeka is native to Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota and has been federally listed as endangered since 1998. Our goals were to determine the present distribution and qualitative status of Topeka shiners throughout its current range in Iowa and characterize the extent of decline in relation to its historic distribution. We compared the current (2016–2017) distribution to distributions portrayed in three earlier time periods. In 2016–2017 Topeka shiners were found in 12 of 20 HUC10 watersheds where they occurred historically. Their status was classified as stable in 21% of the HUC10 watersheds, possibly stable in 25%, possibly recovering in 8%, at risk in 33%, and possibly extirpated in 13% of the watersheds. The increasing trend in percent decline evident in earlier time periods reversed, going from 68% in 2010–11 to 40% in the most recent surveys. Following decades of decline, the status of Topeka shiners in Iowa appears to be improving. One potential reason for the reversal in the distributional decline of Topeka shiners in Iowa is the increasing number of oxbow restorations. Until a standardized monitoring program is established for Iowa, periodic status assessments such as this will be necessary to chronicle progress toward conserving this endangered fish species

    Get your facts right : preschoolers systematically extend both object names and category-relevant facts

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    There is an ongoing debate over the extent to which language development shares common processing mechanisms with other domains of learning. It is well-established that toddlers will systematically extend object labels to similarly-shaped category exemplars (e.g., Landau, Smith, & Jones, 1988; Markman & Hutchinson, 1984). However, previous research is inconclusive as to whether young children will similarly extend factual information about an object to other category members. We explicitly contrast facts varying in category relevance, and test for extension using two different tasks. Three- to four-year-olds (N = 61) were provided with one of three types of information about a single novel object: a category-relevant fact (‘it’s from a place called Modi’), a category-irrelevant fact (‘my uncle gave it to me’), or an object label (‘it’s called a Modi’). At test, children provided with the object name or category-relevant fact were significantly more likely to display systematic category extension than children who learnt the category-irrelevant fact. Our findings contribute to a growing body of evidence that the mechanisms responsible for word learning may be domain-general in nature

    A Systematic Review of the Prevalence and Pattern of Imaging Defined Post-TB Lung Disease

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    Background Tuberculosis is an important risk factor for chronic respiratory disease in resource poor settings. The persistence of abnormal spirometry and symptoms after treatment are well described, but the structural abnormalities underlying these changes remain poorly defined, limiting our ability to phenotype post-TB lung disease in to meaningful categories for clinical management, prognostication, and ongoing research. The relationship between post-TB lung damage and patient-centred outcomes including functional impairment, respiratory symptoms, and health related quality of life also remains unclear. Methods We performed a systematic literature review to determine the prevalence and pattern of imaging-defined lung pathology in adults after medical treatment for pleural, miliary, or pulmonary TB disease. Data were collected on study characteristics, and the modality, timing, and findings of thoracic imaging. The proportion of studies relating imaging findings to spirometry results and patient morbidity was recorded. Study quality was assessed using a modified Newcastle-Ottowa score. (Prospero Registration number CRD42015027958) Results We identified 37 eligible studies. The principle features seen on CXR were cavitation (8.3–83.7%), bronchiectasis (4.3–11.2%), and fibrosis (25.0–70.4%), but prevalence was highly variable. CT imaging identified a wider range of residual abnormalities than CXR, including nodules (25.0–55.8%), consolidation (3.7–19.2%), and emphysema (15.0–45.0%). The prevalence of cavitation was generally lower (7.4–34.6%) and bronchiectasis higher (35.0–86.0%) on CT vs. CXR imaging. A paucity of prospective data, and data from HIV-infected adults and sub-Saharan Africa (sSA) was noted. Few studies related structural damage to physiological impairment, respiratory symptoms, or patient morbidity. Conclusions Post-TB structural lung pathology is common. Prospective data are required to determine the evolution of this lung damage and its associated morbidity over time. Further data are required from HIV-infected groups and those living in sSA

    Evaluation of An Oral Health Education Session for Early Head Start Home Visitors

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    Objectives Home visiting programs promote the education and health of Early Head Start (EHS) children and pregnant women. However, EHS\u27s oral health component is unevenly implemented. We conducted an educational intervention to improve oral health knowledge and motivational interviewing techniques among Wisconsin EHS home visitors. Methods A questionnaire assessing oral health-related knowledge and confidence was administered to home visitors before and after an educational session. Changes between pre/post-responses were analyzed with McNemar\u27s test and Wilcoxon Signed Rank test. Results After the intervention there were increases in both knowledge and confidence related to oral health communication. Knowledge increases were observed in such topics as fluoridation, dental caries, and caregivers’ role in assisting and supervising children\u27s tooth brushing. Conclusions A brief educational intervention was associated with increased home visitor knowledge and confidence in communicating oral health messages to EHS caregivers and pregnant women

    Solution-Phase Synthesis of Heteroatom-Substituted Carbon Scaffolds for Hydrogen Storage

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    This paper reports a bottom-up solution-phase process for the preparation of pristine and heteroatom (boron, phosphorus, or nitrogen)-substituted carbon scaffolds that show good surface areas and enhanced hydrogen adsorption capacities and binding energies. The synthesis method involves heating chlorine-containing small organic molecules with metallic sodium at reflux in high-boiling solvents. For heteroatom incorporation, heteroatomic electrophiles are added to the reaction mixture. Under the reaction conditions, micrometer-sized graphitic sheets assembled by 3−5 nm-sized domains of graphene nanoflakes are formed, and when they are heteroatom-substituted, the heteroatoms are uniformly distributed. The substituted carbon scaffolds enriched with heteroatoms (boron ~7.3%, phosphorus ~8.1%, and nitrogen ~28.1%) had surface areas as high as 900 m^2 g^(−1) and enhanced reversible hydrogen physisorption capacities relative to pristine carbon scaffolds or common carbonaceous materials. In addition, the binding energies of the substituted carbon scaffolds, as measured by adsorption isotherms, were 8.6, 8.3, and 5.6 kJ mol^(−1) for the boron-, phosphorus-, and nitrogen-enriched carbon scaffolds, respectively

    Changes in the capacity of visual working memory in 5- to 10-year-olds

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    Using the Luck and Vogel change detection paradigm, we sought to investigate the capacity of visual working memory in 5-, 7-, and 10-year-olds. We found that performance on the task improved significantly with age and also obtained evidence that the capacity of visual working memory approximately doubles between 5 and 10 years of age, where it reaches adult levels of approximately three to four items
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