1,620 research outputs found

    On the arithmetic Chern character

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    We consider a short sequence of hermitian vector bundles on some arithmetic variety. Assuming that this sequence is exact on the generic fiber we prove that the alternated sum of the arithmetic Chern characters of these bundles is the sum of two terms, namely the secondary Bott Chern character class of the sequence and its Chern character with supports on the finite fibers. Next, we compute these classes in the situation encountered by the second author when proving a "Kodaira vanishing theorem" for arithmetic surfaces

    The Fusion Model of Instructional Design: a proposed model for faculty development programs in technology integration

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    University faculty are increasingly challenged to integrate technology into their teaching to meet the needs of technology-savvy students today. The purpose of this dissertation is to introduce and examine an instructional design model, the Fusion Model of Instructional Design, for designing and implementing more effective faculty development programs in technology integration. The model builds on positive aspects of participatory design (Vincini, 2001), rapid prototyping (Tripp & Bichelmeyer, 1990), and Keller’s (1983) ARCS model of motivation. Key characteristics of the Fusion Model are participation of early adopters in the design and implementation of training, recursive training of early adopters first and then the remaining faculty within one department or a small number of related departments, and on-going formative evaluation through brainstorming and discussion. Two studies were conducted to examine the perceived value, usability, and effectiveness of the Fusion Model in a small southern university. For both studies, the participants were trained on various components of a popular course management system. Study 1 was conducted with two departments for the purpose of piloting of the model. Survey data were collected in Study 1. Study 2 was conducted with two additional departments for further evaluation of the model. Data from Study 2 were collected using both quantitative and qualitative methods. Qualitative data were collected through interviews of faculty participants and the university technology facilitator and the researcher’s observation journal. Results of these studies indicate that the use of Fusion Model of Instructional Design was perceived favorably and produced positive outcomes. Both the technology facilitator and the faculty participants reported positive attitudes toward the training designed, developed, and implemented using the model. The technology facilitator was pleased with the value, usability, and effectiveness of the model because the model allowed for greater faculty participation, customization of the training, and modifications of the sessions when needed. The faculty were pleased because using the model allowed them input in their training which resulted in more participation, more targeted training and support with colleagues in the same department. In a follow-up survey, faculty reported a significantly higher level of technology integration in their teaching and student learning

    Entomological Notes

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    Organic sulfur: a spatially variable and understudied component of marine organic matter

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Longnecker, K., Oswald, L., Soule, M. C. K., Cutter, G. A., & Kujawinski, E. B. Organic sulfur: a spatially variable and understudied component of marine organic matter. Limnology and Oceanography Letters, (2020), doi:10.1002/lol2.10149.Sulfur (S) is a major heteroatom in organic matter. This project evaluated spatial variability in the concentration and molecular‐level composition of organic sulfur along gradients of depth and latitude. We measured the concentration of total organic sulfur (TOS) directly from whole seawater. Our data reveal high variability in organic sulfur, relative to established variability in total organic carbon or nitrogen. The deep ocean contained significant amounts of organic sulfur, and the concentration of TOS in North Atlantic Deep Water (NADW) decreased with increasing age while total organic carbon remained stable. Analysis of dissolved organic matter extracts by ultrahigh resolution mass spectrometry revealed that 6% of elemental formulas contained sulfur. The sulfur‐containing compounds were structurally diverse, and showed higher numbers of sulfur‐containing elemental formulas as NADW moved southward. These measurements of organic sulfur in seawater provide the foundation needed to define the factors controlling organic sulfur in the global ocean.We thank Catherine Carmichael, Winifred Johnson, and Gretchen Swarr for assistance with sample collection and processing, and Joe Jennings for the analysis of inorganic nutrients. The help of the captain and crew of the R/V Knorr and the other cruise participants during the “DeepDOM” cruise is appreciated. Two anonymous reviewers and Patricia Soranno provided thorough comments that greatly improved the manuscript. The ultrahigh resolution mass spectrometry samples were analyzed at the WHOI FT‐MS Users' Facility that is funded by the National Science Foundation (grant OCE‐0619608) and the Gordon and Betty Moore Foundation (GMBF1214). This project was funded by NSF grants OCE‐1154320 (to EBK and KL), the W.M. Marquet Award (to KL), and OCE‐1435708 (to GAC). The authors declare no conflicts of interest

    NDSF technical operations via telecommunications

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    In 2015, the Woods Hole Oceanographic Institution (WHOI) commissioned an external study concerning the use of modern telecommunications and telepresence technologies in the potential reduction of manpower in National Deep Submergence Operations. That study has been completed, and the final report is attached as Appendix A.Funding was provided by the Nereus Legacy Fund at the Woods Hole Oceanographic Institutio

    Full-scale Wind-tunnel and Flight Test of a Fairchild 22 Airplane Equipped with a Zap Flap and Zap Ailerons

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    A wing equipped with a Zap flap and Zap ailerons was tested on a Fairchild 22 airplane in the full-scale wind tunnel and in flight to determine the effect of the flaps and ailerons on the performance and the control characteristics of the airplane. The flaps were 0.30 of the wing chord and 0.83 of the wing span. Two sets of ailerons having equal areas but different proportions were tested, one set being 0.56 of the semispan and 0.18 of the chord and the other set being 0.46 of the semispan and 0.22 of the chord. The wind-tunnel tests showed that, when the ailerons and horizontal tail surfaces were removed, the flaps increased the maximum lift coefficient from 1.48 to 2.39. In flight, the fully deflected flaps decreased the minimum speed from 48.2 to 38.8 miles per hour. The take-off and landing distances were both reduced by the flaps. The wind-tunnel tests showed the ailerons to increase the drag coefficient, at a lift coefficient and Reynolds Number corresponding to the high speed of the airplane, from 0.0432 to 0.0498 and 0.0514, the 0.46 semispan ailerons giving the highest drag. In the flight tests both sets of ailerons were found to give satisfactory rolling action in the normal-flight range. They required relatively large stick forces for their operation, however, and the variation of the forces with aileron deflection was not linear

    Full-scale Wind-tunnel and Flight Tests of a Fairchild 22 Airplane Equipped with a Fowler Flap

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    Full-scale wind-tunnel and flight tests were made of a Fairchild 22 airplane equipped with a Fowler flap to determine the effect of the flap on the performance and control characteristics of the airplane. In the wind-tunnel tests of the airplane with the horizontal tail surfaces removed, the flap was found to increase the maximum lift coefficient from 1.27 to 2.41. In the flight test, the flap was found to decrease the minimum speed from 58.8 to 44.4 miles per hour. The required take-off run to attain an altitude of 50 feet was reduced from 935 feet to 700 feet by the use of the flap, the minimum distance being obtained with five-sixths full deflection. The landing run from a height of 50 feet was reduced one-third. The longitudinal and directional control was adversely affected by the flap, indicating that the design of the tail surfaces is more critical with a flapped than a plain wing

    Dissolved organic matter produced by Thalassiosira pseudonana

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    Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Marine Chemistry 168 (2015): 114-123, doi:10.1016/j.marchem.2014.11.003.Phytoplankton are significant producers of dissolved organic matter (DOM) in marine ecosystems but the identity and dynamics of this DOM remain poorly constrained. Knowledge on the identity and dynamics of DOM are crucial for understanding the molecular-level reactions at the base of the global carbon cycle. Here we apply emerging analytical and computational tools from metabolomics to investigate the composition of DOM produced by the centric diatom Thalassiosira pseudonana. We assessed both intracellular metabolites within T. pseudonana (the endo-metabolome) and extracellular metabolites released by T. pseudonana (the exo-metabolome). The intracellular metabolites had a more variable composition than the extracellular metabolites. We putatively identified novel compounds not previously associated with T. pseudonana as well as compounds that have previously been identified within T. pseudonana’s metabolic capacity (e.g. dimethylsulfoniopropionate and degradation products of chitin). The resulting information will provide the basis for future experiments to assess the impact of T. pseudonana on the composition of dissolved organic matter in marine environments.Instrumentation in the WHOI FT-MS facility was funded by the National Science Foundation MRI program (OCE-0619608) and by the Gordon and Betty T. Moore Foundation (Grant #1214). This work was supported by NSF grant OCE-0928424 to EBK
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