4,250 research outputs found

    An Instrument for Recording the Position of Airplane Control Surfaces

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    N.A.C.A. has developed an instrument which makes a continuous record of the angular position of the control surfaces of an airplane, not only in steady flight but during acrobatics as well. It has proven useful in researches into stability and controllability, and from records obtained from it many otherwise obscure details of piloting technique have been available for the instruction of pilots, from novices to seasoned experts

    MetaboTools: A comprehensive toolbox for analysis of genome-scale metabolic models

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    Metabolomic data sets provide a direct read-out of cellular phenotypes and are increasingly generated to study biological questions. Our previous work revealed the potential of analyzing extracellular metabolomic data in the context of the metabolic model using constraint-based modeling. Through this work, which consists of a protocol, a toolbox, and tutorials of two use cases, we make our methods available to the broader scientific community. The protocol describes, in a step-wise manner, the workflow of data integration and computational analysis. The MetaboTools comprise the Matlab code required to complete the workflow described in the protocol. Tutorials explain the computational steps for integration of two different data sets and demonstrate a comprehensive set of methods for the computational analysis of metabolic models and stratification thereof into different phenotypes. The presented workflow supports integrative analysis of multiple omics data sets. Importantly, all analysis tools can be applied to metabolic models without performing the entire workflow. Taken together, this protocol constitutes a comprehensive guide to the intra-model analysis of extracellular metabolomic data and a resource offering a broad set of computational analysis tools for a wide biomedical and non-biomedical research community

    Buffalo Dancer: The Biography of an Image.

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    This dissertation is the first book-length study to bridge American and Native American art histories and Native studies. To do so, it develops methods of image biography, or following a particular image through space and time. The image in question begins as Karl Bodmer’s watercolor portrait of a Numak'aki [Mandan] Benók Óhate [buffalo bull society] leader, later titled Mandan Buffalo Dancer (1834). Starting from its creation point in Indian Territory, the narrative subsequently tracks Mandan Buffalo Dancer in and out of various historical and cultural contexts, forms, and genres across the nineteenth and twentieth centuries, in both Native American and non-Native settings. Tracing how this story’s various agents utilized print (broadly construed as processes of technological image reproduction), I argue that nineteenth-century systems of racial oppression, based on visual criteria of difference, emerged in part through the very mechanics by which print operates. These mechanics underwrote not only a system of racial notation--the very language of “stereotype,” “cliché,” and “racial typing” belie their sourcing in print technologies--but also a larger, wide-ranging system of knowledge reproduction and distribution that facilitated the containment of Native peoples under the logics of Manifest Destiny. Simultaneously, Native American communities employed print (or auratic cultural practices that reproduce social memory) to promote the continuation of Native societies. These two long histories of print fed the rise of Native political activism in the 1960s and 1970s, as Native communities and artists worked to transform the historical effects of Manifest Destiny’s print enterprise. Writing these histories in parallel, this project produces an infrastructural study of print image production and valuation. It develops a critical, historical, and cross-cultural language for North American print studies. Finally, in assembling its archive of paintings, prints, drawings, photographs, diaries and letters, advertisements, archaeological artifacts, architecture, journalism, ethnological reports, political cartoons, museum displays, literature, and Native language, this study boldly re-imagines its methodological contact zone, whereby Native histories challenge long-standing paradigms of American art history, visual and material culture takes a significant place in Native studies, and Native art history interprets its objects through local languages, histories, and cosmologies.PHDHistory of ArtUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/133439/1/kkronan_1.pd

    The CD4+ T cell methylome contributes to a distinct CD4+ T cell transcriptional signature in Mycobacterium bovis-infected cattle

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    peer-reviewedWe hypothesised that epigenetic regulation of CD4+ T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4+ T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4+ T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4+ T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4+ T cell response during mycobacterial infection in cattle

    Characteristics of a Boat Type Seaplane During Take-off

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    This report, on the planing and get-away characteristics of the F-5-L, gives the results of the second of a series of take-off tests on three different seaplanes conducted by the National Advisory Committee for Aeronautics at the suggestion of the Bureau of Aeronautics, Navy Department. The single-float seaplane was the first tested and the twin-float seaplane is to be the third. The characteristics of the boat type were found to be similar to the single float, the main difference being the increased sluggishness and relatively larger planing resistance of the larger seaplane. At a water speed of 15 miles per hour the seaplane trims aft to about 12 degrees and remains in this angular position while plowing. At 2.25 miles per hour the planing stage is started and the planing angle is immediately lowered to about 10 degrees. As the velocity increases the longitudinal control becomes more effective but over control will produce instability. At the get-away the range of angle of attack is 19 degrees to 11 degrees with velocities from the stalling speed through about 25 per cent of the speed range

    Characteristics of a twin-float seaplane during take-off

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    This report presents the results of an investigation of the planing and get-away characteristics of three representative types of seaplanes, namely, single float, boat, and twin float. The experiments carried out on the single float and boat types have been reported on previously. This report covers the investigation conducted on the twin-float seaplane, the DT-2, and includes as an appendix, a brief summary of the results obtained on all three tests. At low-water speeds, 20 to 30 miles per hour, the seaplane trims by the stern and has a high resistance. Above these speeds the longitudinal control becomes increasingly effective until, with corresponding speeds of 56 to 46 miles per hour. It was further determined that an increase in the load caused little if any change in the water speed at which the maximum angle and resistance occurred, but that it did produce an increase in the maximum angle

    Characteristics of a Single Float Seaplane During Take-off

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    At the request of the Bureau of Aeronautics, Navy Department, the National Advisory Committee for Aeronautics at Langley Field is investigating the get-away characteristics of an N-9H, a DT-2, and an F-5l, as representing, respectively, a single float, a double float, and a boat type of seaplane. This report covers the investigation conducted on the N-9H. The results show that a single float seaplane trims aft in taking off. Until a planing condition is reached the angle of attack is about 15 degrees and is only slightly affected by controls. When planing it seeks a lower angle, but is controllable through a widening range, until at the take-off it is possible to obtain angles of 8 degrees to 15 degrees with corresponding speeds of 53 to 41 M. P. H. or about 40 per cent of the speed range. The point of greatest resistance occurs at about the highest angle of a pontoon planing angle of 9 1/2 degrees and at a water speed of 24 M. P. H

    Experimental Summary on Hadronic Decays: A TAU98 Review

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    Selected results on hadronic decays of the tau lepton from the TAU98 Workshop are reviewed. A comprehensive picture emerges for strange particle branching fractions, and exploration of resonant substructure of both strange and non-strange decays is seen to have matured substantially.Comment: 10 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN
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