270 research outputs found

    New measurement paradigms

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    This collection of New Measurement Paradigms papers represents a snapshot of the variety of measurement methods in use at the time of writing across several projects funded by the National Science Foundation (US) through its REESE and DR K–12 programs. All of the projects are developing and testing intelligent learning environments that seek to carefully measure and promote student learning, and the purpose of this collection of papers is to describe and illustrate the use of several measurement methods employed to achieve this. The papers are deliberately short because they are designed to introduce the methods in use and not to be a textbook chapter on each method. The New Measurement Paradigms collection is designed to serve as a reference point for researchers who are working in projects that are creating e-learning environments in which there is a need to make judgments about students’ levels of knowledge and skills, or for those interested in this but who have not yet delved into these methods

    Postoperative Morbidity and Histopathologic Characteristics of Tonsillar Tissue Following Coblation Tonsillectomy in Children: A Prospective Randomized Single-Blind Study

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    The aim of this prospective randomized single blind study was to determine the depth of thermal damage to tonsillar tissue due to coblation, and to compare it with thermal damage to tonsillar tissue following conventional tonsillectomy; to correlate the depth of thermal damage to tonsillar tissue with the parameters of postoperative morbidity, to compare intraoperative blood loss, postoperative pain severity, time to resuming normal physical activity, and incidence of postoperative bleeding between two groups of tonsillectomized children aged up to 16 years. 72 children aged 3–16 years scheduled for tonsillectomy randomly assigned into two groups submitted either to conventional tonsillectomy with bipolar diathermy coagulation or to coblation tonsillectomy, with a 14-day follow up.Statistically significant differences were observed in the depth of thermal damage to tonsillar tissue (p<0.001), intraoperative blood loss (p<0.004), in postoperative pain severity (p<0.05) and in time to resuming normal physical activity between the two groups (p<0.001). There was no case of reactionary or secondary bleeding in either group. In this paper for the first time we have correlated postoperative morbidity and thermal tissue damage: less thermal damage is associated with less postoperative morbidity

    Phase Heritage: Deciphering Evidence of Pre-Existing Phases via Inherited Crystallographic Orientations

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    The concept of 'phase heritage' (e.g., Timms et al., 2017a) involves microstructural recognition of the former presence of a phase that has since transformed to another via evidence encoded in crystallographic orientations. Phase heritage relies on the phenomenon that newly grown (daughter) phases nucleate with particular crystallographic orientation relationships with the preceding (parent) phase. This phenomenon is common for displacive (i.e., shear or martensitic) transformations, well documented in the metals and ceramics literature, but is relatively uncommon in geosciences. This presentation outlines the concepts behind this approach, showcases results from software for automated analysis of EBSD data, and illustrates examples of polymorphic and dissociation phase transformations in the ZrSiO4-ZrO2-SiO2 system, which has particularly useful applications for 'extreme thermobarometry' in impact environments (Timms et al., 2017a)

    Self-efficacy and work engagement: Test of a chain model

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    Purpose – This study investigates the mediating roles of work and family demands and work–life balance on the relationship between self-efficacy (to regulate work and life) and work engagement. Specifically, it seeks to explain how self-efficacy influences employees’ thought patterns and emotional reactions, which in turn enable them to cope with work and family demands, and ultimately achieve work–life balance and work engagement. Design/methodology/approach – Structural equation modelling (SEM) of survey data obtained from a heterogeneous sample of 1,010 Australian employees is used to test the hypothesised chain mediation model. Findings – The SEM results support the hypothesised model. Self-efficacy was significantly and negatively related to work and family demands, which in turn were negatively associated with work–life balance. Work–life balance, in turn, enabled employees to be engaged in their work. Research limitations/implications – The findings support the key tenets of social cognitive theory and conservation of resources (COR) theory and demonstrate how self-efficacy can lead to work–life balance and engagement despite the presence of role demands. Study limitations (e.g., cross-sectional research design) and future research directions are discussed. Originality/value – This study incorporates COR theory with social cognitive theory to improve understanding of how self-efficacy enhances work–life balance and work engagement through a self-fulfilling cycle in which employees achieve what they believe they can accomplish, and in the process, build other skills and personal resources to manage work and family challenges.Data collection for this research was supported by the Australian Research Council Discovery Project under Grant DP0770109

    Mapping the cis-regulatory architecture of the human retina reveals noncoding genetic variation in disease

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    The interplay of transcription factors and cis-regulatory elements (CREs) orchestrates the dynamic and diverse genetic programs that assemble the human central nervous system (CNS) during development and maintain its function throughout life. Genetic variation within CREs plays a central role in phenotypic variation in complex traits including the risk of developing disease. We took advantage of the retina, a well-characterized region of the CNS known to be affected by pathogenic variants in CREs, to establish a roadmap for characterizing regulatory variation in the human CNS. This comprehensive analysis of tissue-specific regulatory elements, transcription factor binding, and gene expression programs in three regions of the human visual system (retina, macula, and retinal pigment epithelium/choroid) reveals features of regulatory element evolution that shape tissue-specific gene expression programs and defines regulatory elements with the potential to contribute to Mendelian and complex disorders of human vision

    Mineralogy and geochemistry of atypical reduction spheroids from the Tumblagooda Sandstone, Western Australia

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    Funding Information: This research was supported by a CSIRO Mineral Resources studentship, a Curtin University student scholarship and a Minerals Research Institute of Western Australia scholarship. The editors of Sedimentology and three anonymous reviewers are acknowledged for their assistance in improving the manuscript. We would also like to thank Mike Paxman and the Parks and Wildlife Service for permission to sample in Kalbarri National Park. Finally, the authors would like to pay tribute to the memory of Professor Nigel Trewin, whose work laid much of the foundation for this study and many others on the Tumblagooda Sandstone.Peer reviewedPostprin

    Short-term occupations at high elevation during the Middle Paleolithic at Kalavan 2 (Republic of Armenia)

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    The Armenian highlands encompasses rugged and environmentally diverse landscapes and is characterized by a mosaic of distinct ecological niches and large temperature gradients. Strong seasonal fluctuations in resource availability along topographic gradients likely prompted Pleistocene hominin groups to adapt by adjusting their mobility strategies. However, the role that elevated landscapes played in hunter-gatherer settlement systems during the Late Pleistocene (Middle Palaeolithic [MP]) remains poorly understood. At 1640 m above sea level, the MP site of Kalavan 2 (Armenia) is ideally positioned for testing hypotheses involving elevation-dependent seasonal mobility and subsistence strategies. Renewed excavations at Kalavan 2 exposed three main occupation horizons and ten additional low densities lithic and faunal assemblages. The results provide a new chronological, stratigraphical, and paleoenvironmental framework for hominin behaviors between ca. 60 to 45 ka. The evidence presented suggests that the stratified occupations at Kalavan 2 locale were repeated ephemerally most likely related to hunting in a high-elevation within the mountainous steppe landscape.info:eu-repo/semantics/publishedVersio
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