1,089 research outputs found

    Convince Me! A Persuasive Writing Unit for 2nd Grade [2nd grade]

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    “Capturing a Character”: A unit for teaching 2nd-grade students how to understand literary characters

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    This unit is designed for use in a second grade classroom during the ELA block and is focused on the reading comprehension skills of understanding characters (feelings, traits, and motivations) and making inferences. The unit is approximately 10-12 days in length. The first week is dedicated to building vocabulary and the second is to applying the skill. Quality picture books and graphic novels are referenced as mentor texts, and technology is utilized throughout the unit. A group project and performance task are included. By the end of the unit your students should be able to define feelings, traits, and motivations, and understand how these three areas can inform us about a character

    Single phase, single orientation Cu_2O (1 0 0) and (1 1 0) thin films grown by plasma-assisted molecular beam epitaxy

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    Epitaxial growth of cuprous oxide (Cu_2O) has been achieved on (1 0 0) and (1 1 0) orientations of MgO by plasma-assisted molecular beam epitaxy. Growth was investigated using a pure oxygen plasma as well as a 90%Ar/10%O_2 plasma. Cu_2O films grown using pure oxygen on MgO (1 0 0) have a limited growth window and typically exhibit multiple phases and orientations. Films grown on MgO (1 1 0) using pure oxygen are phase stable and predominantly (1 1 0) oriented, with some (2 0 0) orientation present. Films grown using an Ar/O_2 plasma on MgO (1 0 0) have improved phase stability and a single (1 1 0) orientation. Growth on MgO (1 1 0) using an Ar/O_2 plasma yields highly reproducible (1 1 0) oriented single phase Cu_2O films with a much wider growth window, suggesting that this substrate orientation is preferable for Cu_2O phase stability

    Increasing Collisional Activation of Protein Complexes Using Smaller Aperture Source Sampling Cones on a Synapt Q-IM-TOF Instrument with a Stepwave Source

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    Quadrupole-ion mobility-time-of-flight (Q-IM-TOF) mass spectrometers have revolutionized investigation of native biomolecular complexes. High pressures in the sources of these instruments aid transmission of protein complexes through damping of kinetic energy by collisional cooling. Since adducts are removed through collisional heating (declustering), excessive collisional cooling can prevent removal of non-specific adducts from protein ions, leading to inaccurate mass measurements, broad mass spectral peaks, and obfuscation of ligand binding. We show that reducing the source pressure using smaller aperture source sampling cones (SC) in a Waters Synapt G2-Si instrument increases protein ion heating by decreasing collisional cooling, providing a simple way to enhance removal of adducted salts from soluble proteins (GroEL 14-mer) and detergents from a transmembrane protein complex (heptameric Staphylococcus aureus α-hemolysin, αHL). These experiments are supported by ion heating and cooling simulations which demonstrate reduced collisional cooling at lower source pressures. Using these easily-swapped sample cones of different apertures is a facile approach to reproducibly extend the range of activation in Synapt-type instruments

    Lipid Head Group Adduction to Soluble Proteins Follows Gas-Phase Basicity Predictions: Dissociation Barriers and Charge Abstraction

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    Native mass spectrometry analysis of membrane proteins has yielded many useful insights in recent years with respect to membrane protein-lipid interactions, including identifying specific interactions and even measuring binding affinities based on observed abundances of lipid-bound ions after collision-induced dissociation (CID). However, the behavior of non-covalent complexes subjected to extensive CID can in principle be affected by numerous factors related gas- subjected to extensive CID can in principle be affected by numerous factors related gas- subjected to extensive CID can in principle be affected by numerous factors related gas-subjected to extensive CID can in principle be affected by numerous factors related gas- subjected to extensive CID can in principle be affected by numerous factors related gas- subjected to extensive CID can in principle be affected by numerous factors related gas- subjected to extensive CID can in principle be affected by numerous factors related gas- phase chemistry, including gas-phase basicity (GB) and acidity, shared-proton bonds, and other factors. A recent report from our group showed that common lipids span a wide range of GB values. Notably, phosphatidylcholine (PC) and sphingomyelin lipids are more basic than arginine, suggesting they may strip charge upon dissociation in positive ion mode, while phosphoserine lipids are slightly less basic than arginine and may form especially strong shared-proton bonds. Here, we use CID to probe the strength of non-specific gas-phase interactions between lipid head groups and several soluble proteins, used to deliberately avoid possible physiological protein-lipid interactions. The strengths of the protein-head group interactions follow the trend predicted based solely on lipid and amino acid GBs: phosphoserine (PS) head group forms the strongest bonds with these proteins and out-competes the other head groups studied, while glycerophosphocholine (GPC) head groups form the weakest interactions and dissociate carrying away a positive charge. These results indicate that gas-phase thermochemistry can play an important role in determining which head groups remain bound to protein ions with native-like structures and charge states in positive ion mode upon extensive collisional activation

    Development of a fixative protocol using formaldehyde and gluteraldehyde for preservation of microbial art on agar plates.

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    Agar art bridges the gap between science and art, using microbes instead of paint. Afterwards, the art can change in response to microbial fluctuation, meaning preservation of the original art is essential. Here, formaldehyde and glutaraldehyde were investigated as preservatives, involving techniques used in healthcare settings to preserve samples. Formaldehyde was tested at 1.0%, 2.0% and 3.7%, w/v, whereas glutaraldehyde was tested at 1% and 2.5%, w/v. Both compounds and respective concentrations were tested for different time periods. Escherichia coli, Serratia marcescens, Staphlococcus aureus and Micrococcus luteus were used as bacteria for "drawing" the works of art. The effectiveness of fixation was determined using integrated densities and visual assessment. Initially, both compounds showed potential promise, albeit with a loss of bacteria. Ser. marcescens was prone to colour changes and glutaraldehyde caused discolouration of agar and bacteria. These could be caused by a pH decrease in the agar, due to residual free aldehyde groups. Reduction of this was tested using 300 mM sodium metabisulfite to neutralize excess aldehydes. This initially led to reduced bacterial loss and avoided colour changes, however measurements 24 h post-fixation showed colour loss to some bacterial clusters. This study found that, depending on the species, use of at least 2% formaldehyde for a short fixation period (typically 1 min) was the most promising approach for the preservation of art. Given the success of this with different bacteria, it would make a good starting combination for anyone trying to fix agar art; depending on the bacterial species used, methodology refinement may be needed for optimisation. This study shows successful fixation and preservation of different bacterial species on agar for the first time. The impact of this is to preserve agar art while making it safe and non-infective to those in contact with the microbial art

    In vivo killing of Staphylococcus aureus using a light-activated antimicrobial agent

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    Background: The widespread problem of antibiotic resistance in pathogens such as Staphylococcus aureus has prompted the search for new antimicrobial approaches. In this study we report for the first time the use of a light-activated antimicrobial agent, methylene blue, to kill an epidemic methicillin-resistant Staphylococcus aureus (EMRSA-16) strain in two mouse wound models.Results: Following irradiation of wounds with 360 J/cm(2) of laser light (670 nm) in the presence of 100 mu g/ml of methylene blue, a 25-fold reduction in the number of viable EMRSA was seen. This was independent of the increase in temperature of the wounds associated with the treatment. Histological examination of the wounds revealed no difference between the photodynamic therapy (PDT)-treated wounds and the untreated wounds, all of which showed the same degree of inflammatory infiltration at 24 hours.Conclusion: The results of this study demonstrate that PDT is effective at reducing the total number of viable EMRSA in a wound. This approach has promise as a means of treating wound infections caused by antibiotic-resistant microbes as well as for the elimination of such organisms from carriage sites

    Strained alkyne polymers capable of SPAAC via ring-opening metathesis polymerization

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    The incorporation of strained alkynes into polymers is generally achieved by employing step-growth polymerization methods or post-polymerization reactions. Here, we demonstrate that cyclopropenone-masked strained alkynes are tolerant to chain-growth ring-opening metathesis polymerization, and that, upon post-polymerization photochemical demasking with loss of CO, the strained alkyne group appended to each repeating unit can be used to prepare functional (e.g., fluorescent or redox-active) polymers from a common polymer backbone. We support our claims about polymer transformations throughout the manuscript through the inclusion of a complete set of model reactions and characterization data for analogous molecular species. The findings of this study are transferable to other polymeric systems, opening the door to the creation of libraries of multifunctional chain-growth polymers with identical polymer backbones

    Interface stoichiometry control to improve device voltage and modify band alignment in ZnO/Cu_2O heterojunction solar cells

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    The interface stoichiometry of cuprous oxide (Cu_2O) was controlled by adjusting the O_2 and Zn partial pressures during ZnO sputter deposition and measured by high-resolution X-ray photoelectron spectroscopy of ultrathin (<3 nm) ZnO films on Cu_2O. Open-circuit voltage measurements for ZnO/Cu_2O heterojunctions under AM1.5 illumination were measured and it was found that a stoichiometric interface can achieve the voltage entitlement dictated by the band alignment, whereas the non-stoichiometric interface showed large open-circuit voltage deficits. These results highlight not only the need for stoichiometric interfaces in Cu_2O devices, but also a reproducible experimental method for achieving stoichiometric interfaces that could be applied to any potential heterojunction partner. Additionally, valence-band offset measurements indicated changing the interface stoichiometry shifted the band alignment between Cu_2O and ZnO, which accounts for the variation in previously reported band offset values

    Fitness, PA, Perceived Competence, Parental Support, and Literacy Outcomes in the REACH After-School Sports Program

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    The purpose of this study was to assess the effectiveness of the REACH program in increasing physical activity (PA) levels, cardiorespiratory fitness, perceived competence, self-efficacy, parental support, and literacy across a year-long after-school PA intervention. Participants (N = 78) were students who volunteered from after-school program at either one of the two intervention schools or the control schools. Data are presented from two time points: Baseline (Aug/Sep 2017), and Post (end of the school year in May 2018). Data consisted of PA levels measured by PAC-Q, PACER test, Harter’s Perceived Competence questionnaire, parental support, and literacy tests. School differences in post-intervention scores were found in three (parental support, literacy, PACER) of seven intervention-related measures. Most notably parental support was higher in intervention schools over the control and PACER scores were higher in one intervention school than the control. The results demonstrate that data collection methods may need to be reconsidered in diverse low-income schools. The dramatic amount of missing data and lack of student effort points to students perhaps being overwhelmed with standardized tests and performing tasks for researchers. This leads to a dilemma in data collection in after-school programs in low-income schools: researchers need data to understand what is happening but how are students being served by the data collection process? Researchers should consider new approaches to collect data in low-income urban after-school programs to limit loss of data and to make the data collection meaningful to student participants
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