133 research outputs found

    The Boundary-spanning Role of Democratic Learning Communities: Implementing the IDEALS

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    This multi-case study investigates characteristics and practices in schools that expand the traditional boundaries of school leadership and transform schools into democratic learning communities based on the level of implementation of the IDEALS framework. This investigation serves as a modus to illuminate democratic processes that change schools and address the needs of the students, not the needs of the adults in the system. A sample of five purposefully selected high schools, from the Midwest USA, was utilized. The schools serve Grade 9—12 students, but vary in size, residential area and socioeconomic status of the students. This study illuminates some of the challenges and strategies that facilitate or impede the process of creating more democratic schools that expand the boundaries of inquiry and discourse to include a broader range of community stakeholders and that respect and embrace issues of equity.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    The Methoxymethyl Cation cleaves Peptide Bonds

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    Methoxymethyl cations and simple N-acyl amino acids and dipeptides react in the gas phase to form [M + MeOCH2]+ ions which fragment via a number of pathways including amide bond cleavage

    Characterization of [M-H] cations, radicals and anions of glycine in the gas phase: A combined experimental and Ab initio study

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    O’Hair, Richard A.J.; Blanksby, Stephen; Styles, Michelle; Bowie, John H

    A potential surface map of the H-/N(2)O system. The gas phase ion chemistry of HN(2)O-

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    Dunkin, Fehsenfeld and Ferguson have reported that the gas phase reaction between H- and N2O in a flowing afterglow instrument forms HO- and N2 with medium efficiency. The potential surface (UMP2-FC/6-311++G**//RHF/6-311++G**) for the H-/N2O system confirms this to be the predominant reaction following initial approach of H- towards the central nitrogen of N2O to form unstable intermediate [H-(N2O)]. The intermediate then decomposes to HO- and N2 via a deep channel. The potential surface also shows the direct formation of adducts -O-+N(H)=N- and cis HN=NO-. However, these are formed with excess energy: the former converts principally into reactants, while the latter decomposes to HO- and N2. Ions having the formula 'HN2O-' may be formed in the gas phase by the reactions ( i ) HNO-+N2O → HN2O-+NO, and (ii) NH2-+Me3CCH2ONO → HN2O-+Me3CCH2OH. The product anion is stabilized by removal of some of its excess energy by the eliminated neutral. Evidence is presented which indicates that the product is either cis or trans HN=NO-, or a mixture of both. The characteristic ion molecule reaction of HN=NO- involves oxidative oxygen transfer to suitable neutral substrates. For example: HN2O-+CS2 → HS-+N2+COS.John C. Sheldon, Richard A. J. Ohair, Kevin M. Downard, Scott Gronert, Michele Krempp, Charles H. Depuy and John H. Bowi

    Structure and reactivity of the cysteine methyl ester radical cation

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    The structure and reactivity of the cysteine methyl ester radical cation, CysOMe.+, have been examined in the gas phase using a combination of experiment and density functional theory (DFT) calculations. CysOMe.+ undergoes rapid ion-molecule reactions with dimethyl disulfide, allyl bromide, and allyl iodide, but is unreactive towards allyl chloride. These reactions proceed by radical atom or group transfer and are consistent with CysOMe.+ possessing structure 1, in which the radical site is located on the sulfur atom and the amino group is protonated. This contrasts with DFT calculations that predict a captodative structure 2, in which the radical site is positioned on the α carbon and the carbonyl group is protonated, and that is more stable than 1 by 13.0 kJ mol−1. To resolve this apparent discrepancy the gas-phase IR spectrum of CysOMe.+ was experimentally determined and compared with the theoretically predicted IR spectra of a range of isomers. An excellent match was obtained for 1. DFT calculations highlight that although 1 is thermodynamically less stable than 2, it is kinetically stable with respect to rearrangement
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