5,597 research outputs found

    Bilingual Family Literacy Programming in West Michigan: Points of Alignment and Disconnect among Learners, Instructors, and Local Partners

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    This research explores the beliefs and experiences of stakeholders in a family literacy program through the Literacy Center of West Michigan and Head Start for Kent County. The program is currently developing a curriculum to improve outcomes for learner specific goals. Therefore, one motivation behind this research is to analyze the goals, needs, and understandings for the multiple stakeholders within the program. On a national scale, there exists a need to better define the goals of family literacy programming in general. Points of alignment and disconnect for the participants in this study reflect realities that extend beyond the program at the Literacy Center of West Michigan. Goals for stakeholders are, after all, partly inspired by the family literacy needs that are observed on a regular basis for each participant. This study utilized semi-structured interviews with learners, tutors, and local partners that all participate in the program. The research questions included identifying the priorities for all stakeholders, how these priorities were aligned or disconnected with one another, and how stakeholders are communicating these priorities with each other. These questions inform program development by identifying the goals of these stakeholders in order to ensure coordinated efforts. Four learners and their tutors were interviewed, along with three representatives for Head Start for Kent County. The interviews were recorded and themes that emerged from the data were categorized. Results show that communication styles between stakeholders impacted alignment of goals (or lack thereof). Verbal communication and home to school connections were the most frequently identified goals for all stakeholders, but there were also unique goals for each group. These results indicate a need for open and direct dialogue about family literacy programming to align efforts and produce better outcomes for participants

    Quasi-Chemical and Structural Analysis of Polarizable Anion Hydration

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    Quasi-chemical theory is utilized to analyze the roles of solute polarization and size in determining the structure and thermodynamics of bulk anion hydration for the Hofmeister series Clβˆ’^-, Brβˆ’^-, and Iβˆ’^-. Excellent agreement with experiment is obtained for whole salt hydration free energies using the polarizable AMOEBA force field. The quasi-chemical approach exactly partitions the solvation free energy into inner-shell, outer-shell packing, and outer-shell long-ranged contributions by means of a hard-sphere condition. Small conditioning radii, even well inside the first maximum of the ion-water(oxygen) radial distribution function, result in Gaussian behavior for the long-ranged contribution that dominates the ion hydration free energy. The spatial partitioning allows for a mean-field treatment of the long-ranged contribution, leading to a natural division into first-order electrostatic, induction, and van der Waals terms. The induction piece exhibits the strongest ion polarizability dependence, while the larger-magnitude first-order electrostatic piece yields an opposing but weaker polarizability dependence. In addition, a structural analysis is performed to examine the solvation anisotropy around the anions. As opposed to the hydration free energies, the solvation anisotropy depends more on ion polarizability than on ion size: increased polarizability leads to increased anisotropy. The water dipole moments near the ion are similar in magnitude to bulk water, while the ion dipole moments are found to be significantly larger than those observed in quantum mechanical studies. Possible impacts of the observed over-polarization of the ions on simulated anion surface segregation are discussed.Comment: slight revision, in press at J. Chem. Phy

    Calibration of the EDGES High-Band Receiver to Observe the Global 21-cm Signature from the Epoch of Reionization

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    The EDGES High-Band experiment aims to detect the sky-average brightness temperature of the 2121-cm signal from the Epoch of Reionization (EoR) in the redshift range 14.8≳z≳6.514.8 \gtrsim z \gtrsim 6.5. To probe this redshifted signal, EDGES High-Band conducts single-antenna measurements in the frequency range 90βˆ’19090-190 MHz from the Murchison Radio-astronomy Observatory in Western Australia. In this paper, we describe the current strategy for calibration of the EDGES High-Band receiver and report calibration results for the instrument used in the 2015βˆ’20162015-2016 observational campaign. We propagate uncertainties in the receiver calibration measurements to the antenna temperature using a Monte Carlo approach. We define a performance objective of 11~mK residual RMS after modeling foreground subtraction from a fiducial temperature spectrum using a five-term polynomial. Most of the calibration uncertainties yield residuals of 11~mK or less at 95%95\% confidence. However, current uncertainties in the antenna and receiver reflection coefficients can lead to residuals of up to 2020 mK even in low-foreground sky regions. These dominant residuals could be reduced by 1) improving the accuracy in reflection measurements, especially their phase 2) improving the impedance match at the antenna-receiver interface, and 3) decreasing the changes with frequency of the antenna reflection phase.Comment: Updated to match version accepted by Ap

    Uncoupling of T Cell Receptor Zeta Chain Function during the Induction of Anergy by the Superantigen, Staphylococcal Enterotoxin A

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    Staphylococcus aureus enterotoxins have immunomodulatory properties. In this study, we show that Staphylococcal enterotoxin A (SEA) induces a strong proliferative response in a murine T cell clone independent of MHC class II bearing cells. SEA stimulation also induces a state of hypo-responsiveness (anergy). We characterized the components of the T cell receptor (TCR) during induction of anergy by SEA. Most interestingly, TCR zeta chain phosphorylation was absent under SEA anergizing conditions, which suggests an uncoupling of zeta chain function. We characterize here a model system for studying anergy in the absence of confounding costimulatory signals

    Subsonic Swept Fan Blade

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    A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be driven at a at a design speed by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool. Rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades includes an airfoil body. The leading edge of the airfoil body has a swept profile such that, at the design speed, a component of a relative velocity vector of a working gas that is normal to the leading edge is subsonic along the entire radial span
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