113 research outputs found

    Calcitization of aragonitic bryozoans in Cenozoic tropical carbonates from East Kalimantan, Indonesia

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    © The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The file attached is the published version of the article

    Enhancing Visualization Skills-Improving Options aNd Success (EnViSIONS) of Engineering and Technology Students

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    Spatial visualization skills are vital to many careers and in particular to STEM fields. Materials have been developed at Michigan Technological University and Penn State Erie, The Behrend College to assess and develop spatial skills.  The EnViSIONS (Enhancing Visualization Skills-Improving Options aNd Success) project is combining these materials and testing them with pre-college and college students at  seven institutions: Michigan Tech, Penn State Behrend, Purdue University, University of Iowa, Virginia State University, Virginia Tech, and a “Project Lead the Way” course in south-central Arizona.  By removing a barrier to success for students with low visualization skills, particularly women, the project leaders hope to improve the retention of these students in STEM disciplines and to enhance their success. This paper will give a brief overview of the implementations at the university level and the findings

    AA-Amyloidosis Can Be Transferred by Peripheral Blood Monocytes

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    Spongiform encephalopathies have been reported to be transmitted by blood transfusion even prior to the clinical onset. Experimental AA-amyloidosis shows similarities with prion disease and amyloid-containing organ-extracts can prime a recipient for the disease. In this systemic form of amyloidosis N-terminal fragments of the acute-phase reactant apolipoprotein serum amyloid A are the main amyloid protein. Initial amyloid deposits appear in the perifollicular region of the spleen, followed by deposits in the liver. We used the established murine model and induced AA-amyloidosis in NMRI mice by intravenous injections of purified amyloid fibrils (‘amyloid enhancing factor’) combined with inflammatory challenge (silver nitrate subcutaneously). Blood plasma and peripheral blood monocytes were isolated, sonicated and re-injected into new recipients followed by an inflammatory challenge during a three week period. When the animals were sacrificed presence of amyloid was analyzed in spleen sections after Congo red staining. Our result shows that some of the peripheral blood monocytes, isolated from animals with detectable amyloid, contained amyloid-seed that primed for AA-amyloid. The seeding material seems to have been phagocytosed by the cells since the AA-precursor (SAA1) was found not be expressed by the monocytes. Plasma recovered from mice with AA amyloidosis lacked seeding capacity. Amyloid enhancing activity can reside in monocytes recovered from mice with AA-amyloidosis and in a prion-like way trigger amyloid formation in conjunction with an inflammatory disorder. Human AA-amyloidosis resembles the murine form and every individual is expected to be exposed to conditions that initiate production of the acute-phase reactant. The monocyte-transfer mechanism should be eligible for the human disease and we point out blood transfusion as a putative route for transfer of amyloidosis

    The study of atmospheric ice-nucleating particles via microfluidically generated droplets

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    Ice-nucleating particles (INPs) play a significant role in the climate and hydrological cycle by triggering ice formation in supercooled clouds, thereby causing precipitation and affecting cloud lifetimes and their radiative properties. However, despite their importance, INP often comprise only 1 in 10³–10⁶ ambient particles, making it difficult to ascertain and predict their type, source, and concentration. The typical techniques for quantifying INP concentrations tend to be highly labour-intensive, suffer from poor time resolution, or are limited in sensitivity to low concentrations. Here, we present the application of microfluidic devices to the study of atmospheric INPs via the simple and rapid production of monodisperse droplets and their subsequent freezing on a cold stage. This device offers the potential for the testing of INP concentrations in aqueous samples with high sensitivity and high counting statistics. Various INPs were tested for validation of the platform, including mineral dust and biological species, with results compared to literature values. We also describe a methodology for sampling atmospheric aerosol in a manner that minimises sampling biases and which is compatible with the microfluidic device. We present results for INP concentrations in air sampled during two field campaigns: (1) from a rural location in the UK and (2) during the UK’s annual Bonfire Night festival. These initial results will provide a route for deployment of the microfluidic platform for the study and quantification of INPs in upcoming field campaigns around the globe, while providing a benchmark for future lab-on-a-chip-based INP studies

    Bioavailability assessment: Methods to estimate total area (AUC 0-∞) and total amount excreted (A e ∞ ) and importance of blood and urine sampling scheme with application to digoxin

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    Five methods are compared to estimate the total area under the digoxin plasma or serum concentrationtime curve (AUC0-∞) after a single dose of drug. To obtain accurate estimates of AUC0-∞, data required are concentrations at a sufficient number of sampling times to define adequately the concentration-time curve prior to the log-linear phase, and at least three, but preferably four or more equally spaced points in the terminal loglinear phase. One method (designated Method I) requires a digital computer; another (Method III) is the classical method (these two methods do not require equally spaced points in the loglinear phase). Method IIA is the accelerated convergence method of Amidon et al.; Methods IIB and IIC are modifications of this method, but incorporate usual and orthogonal least squares, respectively, which make them more accurate with real (noisy) data. Methods I and IICgave very comparable estimates of AUC0-∞. Results indicate that digoxin administered orally in aqueous solution was completely (100%) absorbed when bioavailability estimates were based on oral and intravenous AUC0-∞ estimates and the actual doses, whereas formerly only about 80% absorption was reported, based on areas, under plasma concentration curves which were truncated at 96 hr. It is shown that the sampling scheme of blood can produce biased apparent bioavailability estimates when areas under truncated curves are employed, but an appropriate sampling scheme and application of method IIyield accurate bioavailability estimates. This is important particularly in those bioavailability studies where one is attempting to determine the appropriate label dose for a new “fastrelease” digoxin preparation relative to the label dose and bioavailability of currently marketed tablets. It is shown that the magnitudes and variability of apparent elimination rate constants and halflives of digoxin, estimated from urinary excretion data by the σ − method, depend on which value of A e ∞ is used. The formerly reported greater interindividual variability of AUC data compared to At data for digoxin is explained in that the AUCs, but not the A e ,'s, involve the renal clearance, which exhibits considerable inter- and intraindividual variation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45073/1/10928_2005_Article_BF01061733.pd

    Predicting Academic Performance: A Systematic Literature Review

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    The ability to predict student performance in a course or program creates opportunities to improve educational outcomes. With effective performance prediction approaches, instructors can allocate resources and instruction more accurately. Research in this area seeks to identify features that can be used to make predictions, to identify algorithms that can improve predictions, and to quantify aspects of student performance. Moreover, research in predicting student performance seeks to determine interrelated features and to identify the underlying reasons why certain features work better than others. This working group report presents a systematic literature review of work in the area of predicting student performance. Our analysis shows a clearly increasing amount of research in this area, as well as an increasing variety of techniques used. At the same time, the review uncovered a number of issues with research quality that drives a need for the community to provide more detailed reporting of methods and results and to increase efforts to validate and replicate work.Peer reviewe
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