927 research outputs found

    Professional Development Based On The Common European Framework of Reference for Languages And The New Ontario French Immersion Curriculum: A Case Study of Reflective Practice

    Get PDF
    In this multi-phase case study, the teacher researcher aimed to determine how teachers can be assisted in implementing some principles of the Common European Framework of Reference for Languages/CEFR (Council of Europe, 2001) into their pedagogical practices for primary-aged children enrolled in early French Immersion programs. Through a series of interviews conducted over three phases and a five-month period, the researcher led the teacher participant through professional development (PD) to shed light on the PD needed for French Immersion and other FSL teachers to adopt key principles of CEFR-inspired pedagogy into their practice. The results suggest that PD should be offered at the board or provincial level for teachers to understand and be able to implement these pedagogical principles. Moreover, assigning early childhood educators who do not know French to work alongside full-day kindergarten French Immersion teachers impedes the ability of those immersion teachers who are familiar with principles of CEFR-inspired teaching to implement them. The results of this empirical study expand on previous research conducted on the feasibility of introducing the CEFR into Canadian FSL pedagogy. This ground-breaking research explores how educators grapple with a pedagogical innovation and the challenges they face when trying to implement it to meet their own and ministry goals

    The Locus Ceruleus in PTSD

    Get PDF
    NO ABSTRACT: This is 750 word encyclopedia entr

    Influence of particle-phase state on the hygroscopic behavior of mixed organic-inorganic aerosols

    Get PDF
    Recent work has demonstrated that organic and mixed organic–inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle-phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic–inorganic aerosol systems with physical states ranging from well-mixed liquids to phase-separated particles to viscous liquids or semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 40 to 90%. Water-uptake measurements were accompanied by HGF and RH-dependent thermodynamic equilibrium calculations using the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. In addition, AIOMFAC-predicted growth curves are compared to several simplified HGF modeling approaches: (1) representing particles as ideal, well-mixed liquids; (2) forcing a single phase but accounting for non-ideal interactions through activity coefficient calculations; and (3) a Zdanovskii–Stokes–Robinson-like calculation in which complete separation of the inorganic and organic components is assumed at all RH values, with water uptake treated separately in each of the individual phases. We observed variability in the characteristics of measured hygroscopic growth curves across aerosol systems with differing phase behaviors, with growth curves approaching smoother, more continuous water uptake with decreasing prevalence of liquid–liquid phase separation and increasing oxygen : carbon ratios of the organic aerosol components. We also observed indirect evidence for the dehydration-induced formation of highly viscous semi-solid phases and for kinetic limitations to the crystallization of ammonium sulfate at low RH for sucrose-containing particles. AIOMFAC-predicted growth curves are generally in good agreement with the HGF measurements. The performances of the simplified modeling approaches, however, differ for particles with differing phase states. This suggests that no single simplified modeling approach can be used to capture the water-uptake behavior for the diversity of particle-phase behavior expected in the atmosphere. Errors in HGFs calculated with the simplified models are of sufficient magnitude to produce substantial errors in estimates of particle optical and radiative properties, particularly for the assumption that water uptake is driven by absorptive equilibrium partitioning with ideal particle-phase mixing

    Thromboembolic complications of COVID-19

    Get PDF
    © 2020, American Society of Emergency Radiology. The symptomology of patients afflicted with novel 2019 coronavirus disease (SARS-CoV-2 or COVID-19) has varied greatly, ranging from the asymptomatic state to debilitating hypoxemic respiratory failure caused by severe atypical viral pneumonia. Patients may also develop a hyper-inflammatory state that can lead to multi-organ failure. It has become increasingly apparent that, as part of the hyper-inflammatory state, COVID-19 infection increases susceptibility to systemic thromboembolic complications that can contribute to rapid clinical deterioration or demise. This article aims to review imaging features of various systemic thrombotic complications in six patients with moderate to severe disease. This case series includes examples of pulmonary embolism, stroke, right ventricular thrombosis, renal vein thrombosis, and aortic thrombosis with leg ischemia

    Design, simulation, and characterization of a radial opposed migration ion and aerosol classifier (ROMIAC)

    Get PDF
    We present the design, simulation, and characterization of the radial opposed migration ion and aerosol classifier (ROMIAC), a compact differential electrical mobility classifier. We evaluate the performance of the ROMIAC using a combination of finite element modeling and experimental validation of two nearly identical instruments using tetra-alkyl ammonium halide mass standards and sodium chloride particles. Mobility and efficiency calibrations were performed over a wide range of particle diameters and flow rates to characterize ROMIAC performance under the range of anticipated operating conditions. The ROMIAC performs as designed, though performance deviates from that predicted using simplistic models of the instrument. The underlying causes of this non-ideal behavior are found through finite element simulations that predict the performance of the ROMIAC with greater accuracy than the simplistic models. It is concluded that analytical performance models based on idealized geometries, flows, and fields should not be relied on to make accurate a priori predictions about instrumental behavior if the actual geometry or fields deviate from the ideal assumptions. However, if such deviations are accurately captured, finite element simulations have the potential to predict instrumental performance. The present prototype of the ROMIAC maintains its resolution over nearly three orders of magnitude in particle mobility, obtaining sub-20 nm particle size distributions in a compact package with relatively low flow rate operation requirements

    Antibodies against prM protein distinguish between previous infection with dengue and Japanese encephalitis viruses.

    Get PDF
    BACKGROUND: In Southeast Asia, dengue viruses often co-circulate with other flaviviruses such as Japanese encephalitis virus, and due to the presence of shared antigenic epitopes it is often difficult to use serological methods to distinguish between previous infections by these flaviviruses. RESULTS: Convalescent sera from 69 individuals who were known to have had dengue or Japanese encephalitis virus infection were tested by western blotting against dengue, Japanese encephalitis and West Nile virus antigens. We determined that individuals who had been infected with dengue viruses had IgG responses against the premembrane protein of dengue viruses but not Japanese encephalitis, whereas individuals who had been infected with Japanese encephalitis had IgG specific for the premembrane protein of Japanese encephalitis virus but not the dengue viruses. None reacted with the premembrane protein of West Nile virus. Using the Pearson Chi Square test, it was determined that the difference between the two groups was highly significant with a p value of <0.001. CONCLUSION: The use of flavivirus premembrane protein in seroepidemiological studies will be useful in determining what flaviviruses have circulated in a community

    Estimation of aboveground biomass of a production forest reserve in Malaysian Borneo using K-nearest neighbor method

    Get PDF
    This study examined the use of the k-nearest neighbour (k-NN) method to estimate aboveground biomass of a logged-over tropical forest in Sabah, Malaysia. To estimate aboveground biomass, field data as well as digital number and normalised difference vegetation index (NDVI) values from Landsat TM-5 data were used to determine the optimum horizontal reference area and the number of reference sample plots (k). An accuracy assessment showed that enhancing the digital number value was superior to enhancing the NDVI value. Root mean square errors of no filtering and 3 × 3 filtering were minimum when k = 4 and k = 5 respectively, when a horizontal reference area of 17 km was applied. The bias was underestimated by 2.01 and 1.62 tonnes ha-1 for k = 4 and k = 5 respectively. Total aboveground biomass of the forest management unit estimated by enhancing the digital number value was 6,873,299 tonnes and average biomass density was 248.8 tonnes ha-1. The results suggest that the k-NN method is an alternative way to estimate and map aboveground biomass of a forest management unit

    Ion Mobility-Mass Spectrometry with a Radial Opposed Migration Ion and Aerosol Classifier (ROMIAC)

    Get PDF
    The first application of a novel differential mobility analyzer, the radial opposed migration ion and aerosol classifier (ROMIAC), is demonstrated. The ROMIAC uses antiparallel forces from an electric field and a cross-flow gas to both scan ion mobilities and continuously transmit target mobility ions with 100% duty cycle. In the ROMIAC, diffusive losses are minimized, and resolution of ions, with collisional cross-sections of 200–2000 Å^2, is achieved near the nondispersive resolution of ~20. Higher resolution is theoretically possible with greater cross-flow rates. The ROMIAC was coupled to a linear trap quadrupole mass spectrometer and used to classify electrosprayed C2–C12 tetra-alkyl ammonium ions, bradykinin, angiotensin I, angiotensin II, bovine ubiquitin, and two pairs of model peptide isomers. Instrument and mobility calibrations of the ROMIAC show that it exhibits linear responses to changes in electrode potential, making the ROMIAC suitable for mobility and cross-section measurements. The high resolution of the ROMIAC facilitates separation of isobaric isomeric peptides. Monitoring distinct dissociation pathways associated with peptide isomers fully resolves overlapping peaks in the ion mobility data. The ability of the ROMIAC to operate at atmospheric pressure and serve as a front-end analyzer to continuously transmit ions with a particular mobility facilitates extensive studies of target molecules using a variety of mass spectrometric methods
    • …
    corecore