250 research outputs found
Gluing Practice at Aircraft Manufacturing Plants
This report records observations and recommendations resulting from an inspection trip to representative aircraft manufacturing establishments and repair stations. This inspection was made for the Navy Department and was specifically in reference to gluing practice at the various places visited. The period of the visits was between November 23, 1926 and February 16, 1927
The Tie Problem and a National Forestry Program
The yearly supply of crossties for our railroads constitutes a heavy demand upon the forest resources of the country. There is a total mileage of steam and electric railways in the United States of approximately 450,000. Over a considerable period of years the annual replacement of ties on both steam and electric lines has been in the neighborhood of 300 ties per mile. On this basis the normal average consumption of crossties would amount to about 135,000,000. In 1920, the Forest Service estimated the normal annual consumption of ties at between 100 million and 125 million, but this estimate apparently did not include the electric railways. Taking a conservative figure of 120,000,000 ties and 36 board feet as the average contents per tie, it is found that the drain upon our forests amounts to approximately 4¼ billion board feet yearly. In terms of cubic feet of standing timber required yearly crossties stand next after fuel, lumber, and posts
Glues Used in Airplane Parts
This report was prepared for the National Advisory Committee for Aeronautics and presents the results of investigations conducted by the Forest Products Laboratory of the United States Forest Service on the manufacture, preparation, application, testing and physical properties of the different types of glues used in wood airplane parts
Human engineering design criteria study Final report
Human engineering design criteria for use in designing earth launch vehicle systems and equipmen
Roles for common MLL/COMPASS subunits and the 19S proteasome in regulating CIITA pIV and MHC class II gene expression and promoter methylation
<p>Abstract</p> <p>Background</p> <p>Studies indicate that the 19S proteasome contributes to chromatin reorganization, independent of the role the proteasome plays in protein degradation. We have previously shown that components of the 19S proteasome are crucial for regulating inducible histone activation events in mammalian cells. The 19S ATPase Sug1 binds to histone-remodeling enzymes, and in the absence of Sug1, a subset of activating epigenetic modifications including histone H3 acetylation, H3 lysine 4 trimethylation and H3 arginine 17 dimethylation are inhibited at cytokine-inducible major histocompatibilty complex (MHC)-II and class II transactivator (CIITA) promoters, implicating Sug1 in events required to initiate mammalian transcription.</p> <p>Results</p> <p>Our previous studies indicate that H3 lysine 4 trimethylation at cytokine-inducible MHC-II and CIITA promoters is dependent on proteolytic-independent functions of 19S ATPases. In this report, we show that multiple common subunits of the mixed lineage leukemia (MLL)/complex of proteins associated with Set I (COMPASS) complexes bind to the inducible MHC-II and CIITA promoters; that overexpressing a single common MLL/COMPASS subunit significantly enhances promoter activity and MHC-II <it>HLA-DRA </it>expression; and that these common subunits are important for H3 lysine 4 trimethylation at MHC-II and CIITA promoters. In addition, we show that H3 lysine 27 trimethylation, which is inversely correlated with H3 lysine 4 trimethylation, is significantly elevated in the presence of diminished 19S ATPase Sug1.</p> <p>Conclusion</p> <p>Taken together, these experiments suggest that the 19S proteasome plays a crucial role in the initial reorganization of events enabling the relaxation of the repressive chromatin structure surrounding inducible promoters.</p
Squeezed States for General Systems
We propose a ladder-operator method for obtaining the squeezed states of
general symmetry systems. It is a generalization of the annihilation-operator
technique for obtaining the coherent states of symmetry systems. We connect
this method with the minimum-uncertainty method for obtaining the squeezed and
coherent states of general potential systems, and comment on the distinctions
between these two methods and the displacement-operator method.Comment: 8 pages, LAUR-93-1721, LaTe
Recommended from our members
Development of wood adhesives and gluing technic
Published in Transactions of A.S.M.E. February 28, 1932
Recommended from our members
Making wood fire retardant
Information reviewed and reaffirmed March 1956
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