4,403 research outputs found

    Enhancement and suppression effects resulting from information structuring in sentences

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    Information structuring through the use of cleft sentences increases the processing efficiency of references to elements within the scope of focus. Furthermore, there is evidence that putting certain types of emphasis on individual words not only enhances their subsequent processing, but also protects these words from becoming suppressed in the wake of subsequent information, suggesting mechanisms of enhancement and suppression. In Experiment 1, we showed that clefted constructions facilitate the integration of subsequent sentences that make reference to elements within the scope of focus, and that they decrease the efficiency with reference to elements outside of the scope of focus. In Experiment 2, using an auditory text-change-detection paradigm, we showed that focus has similar effects on the strength of memory representations. These results add to the evidence for enhancement and suppression as mechanisms of sentence processing and clarify that the effects occur within sentences having a marked focus structure

    Injecting New Workforce Leaders in Tourism, Hospitality and Environmental Science: A Community-Engaged Learning and Immersion Class

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    Tourism, especially nature-based tourism, is a major and growing industry in Maine. Therefore, it is important that colleges and universities graduate leaders into the Maine workforce with specific knowledge of the tourism and hospitality industry and with a connection to the environment in which it is flourishing. To graduate these potential leaders, schools must do a better job at retaining and graduating students from diverse socioeconomic backgrounds. Community-engaged learning, including immersion classes, are a key strategy to increase student persistence in some programs at the University of Southern Maine (USM). Two academic units at USM, the Program in Tourism and Hospitality and the Department of Environmental Science and Policy, collaborate in delivering a colocated intensive immersion class for all new majors. This engagement early in their college career fosters a sense of community among the students and with the industry in which they will work. We argue that this community engagement is a factor contributing to student retention and success in these programs and will help create the creative, resilient, locally active leaders needed to guide sustainable tourism development in Maine

    Laboratory and observational study of the interrelation of the carbonaceous component of interstellar dust and solar system materials

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    By studying the chemical and isotopic composition of interstellar ice and dust, one gains insight into the composition and chemical evolution of the solid bodies in the solar nebula and the nature of the material subsequently brought into the inner part of the solar system by comets and meteorites. It is now possible to spectroscopically probe the composition of interstellar ice and dust in the mid-infrared, the spectral range which is most diagnostic of fundamental molecular vibrations. We can compare these spectra of various astronomical objects (including the diffuse and dense interstellar medium, comets, and the icy outer planets and their satellites) with the spectra of analogs we produce in the laboratory under conditions which mimic those in these different objects. In this way one can determine the composition and abundances of the major constituents of the various ices and place general constraints on the types of organics coating the grains in the diffuse interstellar medium. In particular we have shown the ices in the dense clouds contain H2O, CH3OH, CO, perhaps some NH3 and H2CO, we well as nitriles and ketones or esters. Furthermore, by studying the photochemistry of these ice analogs in the laboratory, one gains insight into the chemistry which takes place in interstellar/precometary ices. Chemical and spectroscopic studies of photolyzed analogs (including deuterated species) are now underway. The results of some of these studies will be presented and implications for the evolution of the biogenic elements in interstellar dust and comets will be discussed

    Near Infrared Spectra of H2O/HCN Mixtures

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    Cassini's VIMS has already returned exciting results interpreting spectra of Saturn's icy satellites. The discovery of unidentified features possibly due to CN compounds inspired the work reported here. We wanted to test HCN as a possibility for explaining these features, and also explore how the features of HCN change when mixed with H2O. We have previously noted that mixing H20 and CO2 produces new spectral features and that those features change with temperature and mixing ratio

    Synthesis and Reactivity of Neutral and Cationic Ruthenium(II) Tris(pyrazolyl)borate Alkylidenes

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    A series of neutral and cationic ruthenium(II) alkylidenes containing the hydrotris(pyrazolyl)borate (Tp) ligand have been prepared. The complex Tp(PCy_3)(Cl)Ru=CHPh (2) was obtained by the reaction of (PCy_3)_2(Cl)_2Ru=CHPh (1) and KTp. Treatment of 2 with AgBF_4 or AgSbF_6 in the presence of a variety of coordinating solvents afforded [Tp(PCy_3)(L)Ru=CHPh]^+ (L = H_2O, CH_3CN, pyridine) in high yield. The dynamic NMR behavior of these new complexes is discussed, and the X-ray crystal structure of [Tp(PCy_3)(H_2O)Ru=CHPh]BF_4 (3) is reported. Alkylidenes 2−5 alone do not catalyze olefin metathesis reactions. However, complex 2 is activated for ring-closing metathesis by the addition of HCl, CuCl, and AlCl_3

    Deoxyfluorination of (Hetero)aryl Aldehydes Using Tetramethylammonium Fluoride and Perfluorobutanesulfonyl Fluoride or Trifluoromethanesulfonic Anhydride

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    This Communication describes the conversion of (hetero)aryl aldehydes into the corresponding (hetero)aryl difluoromethyl products using anhydrous NMe4F in combination with perfluorobutanesulfonyl fluoride or trifluoromethanesulfonic anhydride.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154980/1/ijch201900066-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154980/2/ijch201900066_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154980/3/ijch201900066.pd

    Impact of Oxidation State on Reactivity and Selectivity Differences between Nickel(III) and Nickel(IV) Alkyl Complexes

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    Described is a systematic comparison of factors impacting the relative rates and selectivities of C(sp3)−C and C(sp3)−O bond‐forming reactions at high‐valent Ni as a function of oxidation state. Two Ni complexes are compared: a cationic octahedral NiIV complex ligated by tris(pyrazolyl)borate and a cationic octahedral NiIII complex ligated by tris(pyrazolyl)methane. Key features of reactivity/selectivity are revealed: 1) C(sp3)−C(sp2) bond‐forming reductive elimination occurs from both centers, but the NiIII complex reacts up to 300‐fold faster than the NiIV, depending on the reaction conditions. The relative reactivity is proposed to derive from ligand dissociation kinetics, which vary as a function of oxidation state and the presence/absence of visible light. 2) Upon the addition of acetate (AcO−), the NiIV complex exclusively undergoes C(sp3)−OAc bond formation, while the NiIII analogue forms the C(sp3)−C(sp2) coupled product selectively. This difference is rationalized based on the electrophilicity of the respective M−C(sp3) bonds, and thus their relative reactivity towards outer‐sphere SN2‐type bond‐forming reactions.The high point: This report describes a systematic comparison of factors impacting the relative rates and selectivities of C(sp3)−C and C(sp3)−O bond‐forming reactions at high‐valent Ni centers as a function of oxidation state (NiIII versus NiIV). Two Ni complexes are compared: a cationic octahedral NiIV complex ligated by tris(pyrazolyl)borate and a cationic octahedral NiIII complex ligated by tris(pyrazolyl)methane.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150547/1/anie201903638.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150547/2/anie201903638-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150547/3/anie201903638_am.pd

    Added Value of Combining Multiple Optical and Acoustic Instruments When Characterizing Fine-Grained Estuarine Suspensions

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    Various optical and acoustic instruments have specific advantages and limitations for characterizing suspensions, and when used together more information can be obtained than with one instrument alone. The LISST 100X, for example, is a powerful tool for estimating particle size distribution, but because of the inversion method used to determine the size distribution, it is difficult to distinguish two dominate populations that peak close to one another, especially among larger grain sizes. In the York River estuary, VA, additional information obtained through the deployment of a RIPScam camera system and an ADV along with the LISST 100X allowed differentiation between populations of resilient pellets and flocs in suspension close to the bed and how the populations varied over a tidal cycle. A second example of instrument pairing providing additional information was the use of a PICS video imaging system in the York River to verify the conditions under which use of the ADV Reynolds flux method was valid for estimating settling velocity of suspended particle populations
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