4,893 research outputs found

    Assessment of the Calibration of Periodontal Diagnosis and Treatment Planning Among Dental Students at Three Dental Schools

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    Calibration in diagnosis and treatment planning is difficult to achieve due to variations that exist in clinical interpretation. To determine if dental faculty members are consistent in teaching how to diagnose and treat periodontal disease, variations among dental students can be evaluated. A previous study reported high variability in diagnoses and treatment plans of periodontal cases at Indiana University School of Dentistry. This study aimed to build on that one by extending the research to two additional schools: Marquette University School of Dentistry and West Virginia University School of Dentistry. Diagnosis and treatment planning by 40 third- and fourth-year dental students were assessed at each of the schools. Students were asked to select the diagnosis and treatment plans on a questionnaire pertaining to 11 cases. Their responses were compared using chi-square tests, and multirater kappa statistics were used to assess agreement between classes and between schools. Logistic regression models were used to evaluate the effects of school, class year, prior experience, and GPA/class rank on correct responses. One case had a statistically significant difference in responses between third- and fourth-year dental students. Kappas for school agreement and class agreement were low. The students from Indiana University had higher diagnosis and treatment agreements than the Marquette University students, and the Marquette students fared better than the West Virginia University students. This study can help restructure future periodontal courses for a better understanding of periodontal diagnosis and treatment planning

    Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

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    A method combining photogrammetry with ballistic analysis is demonstrated to identify flying debris in a rocket launch environment. Debris traveling near the STS-124 Space Shuttle was captured on cameras viewing the launch pad within the first few seconds after launch. One particular piece of debris caught the attention of investigators studying the release of flame trench fire bricks because its high trajectory could indicate a flight risk to the Space Shuttle. Digitized images from two pad perimeter high-speed 16-mm film cameras were processed using photogrammetry software based on a multi-parameter optimization technique. Reference points in the image were found from 3D CAD models of the launch pad and from surveyed points on the pad. The three-dimensional reference points were matched to the equivalent two-dimensional camera projections by optimizing the camera model parameters using a gradient search optimization technique. Using this method of solving the triangulation problem, the xyz position of the object's path relative to the reference point coordinate system was found for every set of synchronized images. This trajectory was then compared to a predicted trajectory while performing regression analysis on the ballistic coefficient and other parameters. This identified, with a high degree of confidence, the object's material density and thus its probable origin within the launch pad environment. Future extensions of this methodology may make it possible to diagnose the underlying causes of debris-releasing events in near-real time, thus improving flight safety.Comment: 26 pages, 11 figures, 3 table

    Inverse monoids and immersions of 2-complexes

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    It is well known that under mild conditions on a connected topological space X\mathcal X, connected covers of X\mathcal X may be classified via conjugacy classes of subgroups of the fundamental group of X\mathcal X. In this paper, we extend these results to the study of immersions into 2-dimensional CW-complexes. An immersion f:DCf : {\mathcal D} \rightarrow \mathcal C between CW-complexes is a cellular map such that each point yDy \in {\mathcal D} has a neighborhood UU that is mapped homeomorphically onto f(U)f(U) by ff. In order to classify immersions into a 2-dimensional CW-complex C\mathcal C, we need to replace the fundamental group of C\mathcal C by an appropriate inverse monoid. We show how conjugacy classes of the closed inverse submonoids of this inverse monoid may be used to classify connected immersions into the complex

    Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM): a trial for children with sickle cell anemia

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    Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic sub-Saharan Africa, where the greatest sickle-cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, and hydroxyurea-associated neutropenia could worsen infections. NOHARM (Novel use Of Hydroxyurea in an African Region with Malaria) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda, comparing hydroxyurea to placebo at 20 ± 2.5 mg/kg per day for 12 months. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events (AEs), clinical and laboratory effects, and hematological toxicities. Children received either hydroxyurea (N = 104) or placebo (N = 103). Malaria incidence did not differ between children on hydroxyurea (0.05 episodes per child per year; 95% confidence interval [0.02, 0.13]) vs placebo (0.07 episodes per child per year [0.03, 0.16]); the hydroxyurea/placebo malaria incidence rate ratio was 0.7 ([0.2, 2.7]; P = .61). Time to infection also did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%; P = .001). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, with decreased leukocytes and reticulocytes. Serious AEs, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Three deaths occurred (2 hydroxyurea, 1 placebo, and none from malaria). Hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased severe malaria, infections, or AEs. Hydroxyurea provides SCA-related laboratory and clinical efficacy, but optimal dosing and monitoring regimens for Africa remain undefined. This trial was registered at www.clinicaltrials.gov as #NCT01976416

    Cohesion, coherence and connectedness: The 3C model for enabling-course design to support student transition to university

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    Recent Australian government policy has focused on attracting students from under-represented and diverse groups to tertiary education with university enabling courses one pathway for these students. The trend towards broader participation has altered traditional perceptions of a typical university student and raised delivery challenges. The ability to engage these students as learners and improve their academic outcomes and confidence towards successful course completion, is increasingly important to universities because of attrition costs to governments, students and higher education institutions, and is increasingly reflected in academic literature. While strategic student support options have been examined in detail, less focus has been applied to the enabling programs themselves; with little published about what actually happens at the course implementation level, to encourage conditions that support student progression. This paper reports on the re-development of an enabling course at an Australian university committed to breaking down barriers that restrict entry to education. Cohesion, coherence and connectedness emerged as central principles guiding leadership style, course design and development, staff-student communication and collaborative teaching and learning approaches. Student voices describe the lived experience of course development and delivery influenced by these principles. University retention and progression statistics and student unit teaching evaluation data were used to evaluate the impact on student satisfaction and transition. The outcome of the research highlights that building a collaborative course culture based on a 3C model of cohesion, coherence and connectedness when, used interdependently, improves students’ confidence, skills and knowledge to successfully transition to undergraduate tertiary study

    Detection and Identification of Molecular Water Pollutants by Laser Raman Spectroscopy

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    Laser Raman spectroscopy is evolving into a primary tool for the Identification of molecular water pollutants. This study pushes the limits of detectivity of carbon disulfide and benzene to ~ 20 ppm in water solutions using a high-resolution Raman spectrometer, cooled detectors, and photon counting techniques. The primary limiting factors were found to be the low throughput and the scattered light performance of the monochromator as well as insufficient laser energy. An optomized design for a pollution-measuring instrument is suggested, and a prototype has been built which is useful with any value of excitation energy short of sample degrading. The present instrument scans spectrum windows with fixed preselecting filters followed by a small single monochromator with high throughput. No detector cooling or refinements in signal processing were attempted. The resulting detectivity with 20 mw of laser power was only 1000 ppm. However, the scattered light background or optical noise is unmeasurable except at the laser frequency, where it was a maximum of six percent of full scale measured against the 992 cm-1 Raman band of benzene. Equipped with an ion laser a practical field instrument capable of detectivity of 1 ppm will cost about 20,000.Theinstrumentdescribedhereincanbebuiltfor20,000. The instrument described herein can be built for 4,000, less laser

    VAB Temperature and Humidity Study

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    In 2012, 17 data loggers were placed in the VAB to measure temperature and humidity at 10-minute intervals over a one-year period. In 2013, the data loggers were replaced with an upgraded model and slight adjustments to their locations were made to reduce direct solar heating effects. The data acquired by the data loggers was compared to temperature data provided by three wind towers located around the building. It was found that the VAB acts as a large thermal filter, delaying and reducing the thermal oscillations occurring outside of the building. This filtering is typically more pronounced at higher locations in the building, probably because these locations have less thermal connection with the outside. We surmise that the lower elevations respond more to outside temperature variations because of air flow through the doors. Temperatures inside the VAB rarely exceed outdoor temperatures, only doing so when measurements are made directly on a surface with connection to the outside (such as a door or wall) or when solar radiation falls directly on the sensor. A thermal model is presented to yield approximate filter response times for various locations in the building. Appendix A contains historical thermal and humidity data from 1994 to 2009

    “Digital James Dickey” Developing an App for the iPad based on a poem by James Dickey (grade level 11 & 12)

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    The purpose of our project was to create an app for the ipad based on a nature poem by James Dickey that could be used by a high school teacher in a classroom. The app includes a poem, video readings by the poet, perspectives (comment and literary criticisms) by a number of experts, biography, a gallery of photos, and a resources page. In fall of 2013 we will test the app in the high school classroo
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