1,370 research outputs found

    A cross-sectional analysis of video games and attention deficit hyperactivity disorder symptoms in adolescents

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    BACKGROUND: Excessive use of the Internet has been associated with attention deficit hyperactivity disorder (ADHD), but the relationship between video games and ADHD symptoms in adolescents is unknown. METHOD: A survey of adolescents and parents (n = 72 adolescents, 72 parents) was performed assessing daily time spent on the Internet, television, console video games, and Internet video games, and their association with academic and social functioning. Subjects were high school students in the ninth and tenth grade. Students were administered a modified Young's Internet Addiction Scale (YIAS) and asked questions about exercise, grades, work, and school detentions. Parents were asked to complete the Conners' Parent Rating Scale (CPRS) and answer questions regarding medical/psychiatric conditions in their child. RESULTS: There was a significant association between time spent playing games for more than one hour a day and YIAS (p < 0.001), overall grade point average (p ≤ 0.019), and the "Inattention" and "ADHD" components of the CPRS (p ≤ 0.001 and p ≤ 0.020, respectively). No significant association was found between body mass index (BMI), exercise, number of detentions, or the "Oppositional" and "Hyperactivity" components of CPRS and video game use. CONCLUSION: Adolescents who play more than one hour of console or Internet video games may have more or more intense symptoms of ADHD or inattention than those who do not. Given the possible negative effects these conditions may have on scholastic performance, the added consequences of more time spent on video games may also place these individuals at increased risk for problems in school

    A database management capability for Ada

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    The data requirements of mission critical defense systems have been increasing dramatically. Command and control, intelligence, logistics, and even weapons systems are being required to integrate, process, and share ever increasing volumes of information. To meet this need, systems are now being specified that incorporate data base management subsystems for handling storage and retrieval of information. It is expected that a large number of the next generation of mission critical systems will contain embedded data base management systems. Since the use of Ada has been mandated for most of these systems, it is important to address the issues of providing data base management capabilities that can be closely coupled with Ada. A comprehensive distributed data base management project has been investigated. The key deliverables of this project are three closely related prototype systems implemented in Ada. These three systems are discussed

    Impacts of climate change: challenges of flooding in coastal East Asia

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    Over recent years a body of evidence has grown to suggest that East Asia is experiencing the effects of climate change. Allied to this is that coastal populations and economic assets are becoming more vulnerable to flood hazards. Flood vulnerability has increased owing to the combination of a number of human and physical variables: a) rapid coastal urban growth, b) anthropogenic changes to the environment, such as land subsidence through natural resource extraction or the removal of natural protective barriers, and c) increase in frequency and magnitude of coastal hazards associated with typhoons, storm surges, and sea-level rise. East Asia’s population is highly concentrated on low-lying coastal regions and deltaic cities are especially at risk. However, effective adaptation to climate impacts on many coasts is yet to develop. In this chapter, the drivers of coastal vulnerability are reviewed and examined in East Asia, exemplified by the Pearl River Delta (PRD), and its megacities of Guangzhou, Hong Kong and Shenzhen. The population of the PRD is expected to reach 120 million by 2050 and the delta is one of the most important economic centres in East Asia. Flood risk is substantial in the PRD, but flood-risk management appears to suffer from a lack of sufficient strategic planning to prepare for future climate extremes. Drawing on international experience of climate change adaptation and flood risk management, we suggest a path forward to develop adaptation strategies for deltaic and coastal cities in East Asia

    Fourth and Fifth Grade Departmentalization: A Transition to Middle School

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    The difficulties involved in the transition for students leaving elementary school, where there typically exists little departmentalization, to the middle school, where departmentalization is the primary structure, have often been noted by scholars. While some studies cited in this work indicated a decrease in student achievement with the implementation of departmentalization, this approach should not be categorically rejected. In this regard, this study examines how elementary students can begin to be better prepared in fourth and fifth grades to enter the departmentalization system

    The Functional Relationships and Use of Going-In and Going-Out Capitalization Rates

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    In performing a Discounted Cash Flow Analysis for an income-producing property, a traditional rule-of-thumb indicates that the going-out capitalization rate should be one-half to one percent higher than the going-in capitalization rate. So far, there has been no theoretical model or empirical evidence to support or to dispute this assertion. This paper develops a model to examine the determinants of the going-out capitalization rate, as well as the relationship between going-in and going-out capitalization rates in a complete market setting. The proposed model indicates that the rule-of-thumb can be challenged, and the selection of an appropriate going-out capitalization rate requires a careful examination of the changes in the assumed income-growth rates, changes in the assumed required rates of return, and changes in the assumed property-appreciation rates during and after the projected holding period. The functional relationship between the property-appreciation rate assumption required for Ellwood methods and the going-out capitalization rate assumption required for DCF analysis also is derived.

    Developmental dyscalculia and low numeracy in Chinese children

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    Children struggle with mathematics for different reasons. Developmental dyscalculia and low numeracy - two kinds of mathematical difficulties - may have their roots, respectively, in poor understanding of exact non-symbolic numerosities and of symbolic numerals. This study was the first to explore whether Chinese children, despite cultural and linguistic factors supporting their mathematical learning, also showed such mathematical difficulties and whether such difficulties have measurable impact on children's early school mathematical performance. First-graders, classified as dyscalculia, low numeracy, or normal achievement, were compared for their performance in various school mathematical tasks requiring a grasp of non-symbolic numerosities (i.e., non-symbolic tasks) or an understanding of symbolic numerals (i.e., symbolic tasks). Children with dyscalculia showed poorer performance than their peers in non-symbolic tasks but not symbolic ones, whereas those with low numeracy showed poorer performance in symbolic tasks but not non-symbolic ones. As hypothesized, these findings suggested that dyscalculia and low numeracy were distinct deficits and caused by deficits in non-symbolic and symbolic processing, respectively. These findings went beyond prior research that only documented generally low mathematical achievements for these two groups of children. Moreover, these deficits appeared to be persistent and could not be remedied simply through day-to-day school mathematical learning. The present findings highlighted the importance of tailoring early learning support for children with these distinct deficits, and pointed to future directions for the screening of such mathematical difficulties among Chinese children. © 2013 Elsevier Ltd.postprin

    Sig-Networks toolkit: signature networks for longitudinal language modelling

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    We present an open-source, pip installable toolkit, Sig-Networks, the first of its kind for longitudinal language modelling. A central focus is the incorporation of Signature-based Neural Network models, which have recently shown success in temporal tasks. We apply and extend published research providing a full suite of signature-based models. Their components can be used as PyTorch building blocks in future architectures. Sig-Networks enables task-agnostic dataset plug-in, seamless pre-processing for sequential data, parameter flexibility, automated tuning across a range of models. We examine signature networks under three different NLP tasks of varying temporal granularity: counselling conversations, rumour stance switch and mood changes in social media threads, showing SOTA performance in all three, and provide guidance for future tasks. We release the Toolkit as a PyTorch package with an introductory video, Git repositories for preprocessing and modelling including sample notebooks on the modeled NLP tasks

    Molecular characterization of the genes encoding the tungsten-containing aldehyde ferredoxin oxidoreductase from Pyrococcus furiosus and formaldehyde ferredoxin oxidoreductase from Thermococcus litoralis

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    The hyperthermophilic archaea Pyrococcus furiosus and Thermococcus litoralis contain the tungstoenzymes aldehyde ferredoxin oxidoreductase, a homodimer, and formaldehyde ferredoxin oxidoreductase, a homotetramer. herein we report the cloning and sequencing of the P. furiosus gene aor (605 residues; M_r, 66,630) and the T. litoralis gene for (621 residues; M_r, 68,941)

    A comparison of novel and conventional fabrication methods for auxetic foams for sports safety applications

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    This study compares fabrication methods for auxetic foam intended for use in sports safety equipment. Thermo-mechanical conversion methods were applied using: i) cubic moulds (150x150x150 mm), ii) cuboidal moulds (150x150x30 mm) & iii) cuboidal moulds (150x150x30 mm) with through-thickness pins. The cuboidal moulds having one reduced dimension relative to the cubic moulds enable faster heat transfer and more consistent through-thickness compression to the foam during conversion. The through-thickness pins allow greater control of in-plane compression throughout the bulk of the converted foam. Samples were compared using: i) density measurements and measurements of total surface folding (length multiplied by depth), ii) quasistatic compressive load/unload tests to obtain specific strain energy, stress/strain relationship and Poisson's ratio, iii) impact testing on a bespoke drop rig based on a standard for cricket pads (BS 6183-3: 2000, EN 2001) at 5, 10 and 15 J & iv) microscopic images of dissected samples to confirm their auxetic (re-entrant) structure. Samples fabricated in cuboidal moulds show less variation in final density, axial compressive stiffness and specific strain energy between samples than those cut from monoliths fabricated in cubic moulds. Samples created with through-thickness pins exhibited reduced surface folding. Greater control over final properties paves the way for further work designing auxetic foams for sport safety equipment
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