125 research outputs found

    Self-Directed Learning: A Potential Predictor of Technology Integration Confidence among Preservice Teachers

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    The purpose of this study was to examine the relationship between self-directed learning (SDL) and the confidence to integrate technology into the classroom among preservice K-12 teachers enrolled at a large southeastern university. The intent was to determine the extent to which SDL is related to technology integration confidence and, further, to what extent SDL predicts technology integration confidence. In this study, the Personal Responsibility Orientation—Self-Directed Learning Scale (PRO-SDLS) (Stockdale, 2003; Stockdale & Brockett, 2010) was used to measure levels of learner self-direction. Additionally, the Technology Integration Confidence Scale (TICS) (Browne, 2009) was revised (TICS-R) and was used to measure the confidence to integrate technology into the classroom. To conduct this study, a teacher education program at one large, southeastern university was chosen as the population. Of this population, coordinators for two courses offered in the teacher education program gave permission to survey their students. Of these two courses, 143 preservice teachers were contacted, 115 responded, and 102 fully participated. Analysis was conducted to investigate the relationships between the factors of SDL and technology integration confidence. Demographic variables of age, gender, ethnicity, teacher education program, GPA, and whether or not they had completed the teacher education technology course at this university were also examined, but were primarily intended to provide a profile of the sample. This study revealed that SDL has both a significant relationship with and is a predictor of technology integration confidence. Significant relationships were found among the factors of the PRO-SDLS and the subscales of the TICS-R. The strongest relationship was between self-efficacy and technology integration confidence. Self-directed learning was found to predict technology integration confidence at a statistically significant level. The reliability of the PRO-SDLS was found to be consistent with previous research, and the TICS-R was found to be highly reliable, giving promise to future use and further development. Based on these results, this study includes implications for preservice teacher education, as well as recommendations for future research

    Biodiversity and Ecosystem Informatics: Event and Process Tagging for Information Integration for the International Gulf of Main Watershed

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    This incubation proposal addresses the issue of integrating large, diverse, and autonomous collections of scientific data within a complex institutional setting. The goal is to convert these autonomous collections into a shareable repository that supports synthesis of data through new metadata structures based on events and processes. The institutional setting is the data and data-gathering activities of over 80 agencies, NGOS, and academic and research institutions operating within the Gulf of Maine watershed. The metadata development will be coordinated by library and spatial information scientists working jointly with domain scientists. An essential task of this incubation effort will be the development of a shared understanding of environmental processes and events that becomes a shareable ontology.Libraries play a vital role in organizing intellectual access to creative works. Scientific data has tended to be outside this traditional purview and has thus lacked the benefits of cataloging and indexing that promote shared access. We are proposing a new metadata structure that exploits common units of analysis in environmental studies: events and processes. Associating scientific data sets with event and process tags, in addition to other metadata elements, can substantially improve the ability to integrate and synthesize diverse scientific collections. The metadata initiative of this proposal will lay the foundation for specifying events and processes through the collaboration of data collections content specialists and information management specialists

    Gene translocation links insects and crustaceans

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62560/1/392667a0.pd

    Sulfa or Sulfone Prophylaxis and Geographic Region Predict Mutations in the Pneumocystis carinii Dihydropteroate Synthase Gene

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    To determine factors associated with mutations in the Pneumocystis carinii dihydropteroate synthase (DHPS) gene, a prospective study of human immunodeficiency virus (HIV)-infected patients with confirmed P. carinii pneumonia was conducted in Atlanta, Seattle, and San Francisco. Clinical information was obtained from patient interview and chart abstraction. DHPS genotype was determined from DNA sequencing. Overall, 76 (68.5%) of 111 patients had a mutant DHPS genotype, including 22 (81.5%) of 27 patients from San Francisco. In multivariate analysis, sulfa or sulfone prophylaxis and study site were independent predictors of a mutant genotype. Fourteen (53.8%) of 26 patients who were newly diagnosed with HIV infection and had never taken prophylaxis had a mutant genotype. The significance of geographic location as a risk factor for mutant genotype and the high proportion of mutant genotypes among persons never prescribed prophylaxis, including those newly diagnosed with HIV infection, provide indirect evidence that these mutations are transmitted from person to person either directly or through a common environmental source

    Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy.

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    BACKGROUND: The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials. METHODS: In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up. RESULTS: Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17-6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03-5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12-2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface. CONCLUSIONS: Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials

    Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30°N

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    Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): B07103, doi:10.1029/2010JB007931.Expeditions 304 and 305 of the Integrated Ocean Drilling Program cored and logged a 1.4 km section of the domal core of Atlantis Massif. Postdrilling research results summarized here constrain the structure and lithology of the Central Dome of this oceanic core complex. The dominantly gabbroic sequence recovered contrasts with predrilling predictions; application of the ground truth in subsequent geophysical processing has produced self-consistent models for the Central Dome. The presence of many thin interfingered petrologic units indicates that the intrusions forming the domal core were emplaced over a minimum of 100–220 kyr, and not as a single magma pulse. Isotopic and mineralogical alteration is intense in the upper 100 m but decreases in intensity with depth. Below 800 m, alteration is restricted to narrow zones surrounding faults, veins, igneous contacts, and to an interval of locally intense serpentinization in olivine-rich troctolite. Hydration of the lithosphere occurred over the complete range of temperature conditions from granulite to zeolite facies, but was predominantly in the amphibolite and greenschist range. Deformation of the sequence was remarkably localized, despite paleomagnetic indications that the dome has undergone at least 45° rotation, presumably during unroofing via detachment faulting. Both the deformation pattern and the lithology contrast with what is known from seafloor studies on the adjacent Southern Ridge of the massif. There, the detachment capping the domal core deformed a 100 m thick zone and serpentinized peridotite comprises ∼70% of recovered samples. We develop a working model of the evolution of Atlantis Massif over the past 2 Myr, outlining several stages that could explain the observed similarities and differences between the Central Dome and the Southern Ridge

    A second planet transiting LTT 1445A and a determination of the masses of both worlds

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    K.H. acknowledges support from STFC grant ST/R000824/1.LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 pc. The primary star LTT 1445A (0.257 M⊙) is known to host the transiting planet LTT 1445Ab with an orbital period of 5.36 days, making it the second-closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using Transiting Exoplanet Survey Satellite data, we present the discovery of a second planet in the LTT 1445 system, with an orbital period of 3.12 days. We combine radial-velocity measurements obtained from the five spectrographs, Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, High Accuracy Radial Velocity Planet Searcher, High-Resolution Echelle Spectrometer, MAROON-X, and Planet Finder Spectrograph to establish that the new world also orbits LTT 1445A. We determine the mass and radius of LTT 1445Ab to be 2.87 ± 0.25 M⊕ and 1.304-0.060+0.067 R⊕, consistent with an Earth-like composition. For the newly discovered LTT 1445Ac, we measure a mass of 1.54-0.19+0.20 M⊕ and a minimum radius of 1.15 R⊕, but we cannot determine the radius directly as the signal-to-noise ratio of our light curve permits both grazing and nongrazing configurations. Using MEarth photometry and ground-based spectroscopy, we establish that star C (0.161 M⊙) is likely the source of the 1.4 day rotation period, and star B (0.215 M⊙) has a likely rotation period of 6.7 days. We estimate a probable rotation period of 85 days for LTT 1445A. Thus, this triple M-dwarf system appears to be in a special evolutionary stage where the most massive M dwarf has spun down, the intermediate mass M dwarf is in the process of spinning down, while the least massive stellar component has not yet begun to spin down.Publisher PDFPeer reviewe
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