890 research outputs found

    On the logarithmic-singularity correction in the kernel function method of subsonic lifting-surface theory

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    A logarithmic-singularity correction factor is derived for use in kernel function methods associated with Multhopp's subsonic lifting-surface theory. Because of the form of the factor, a relation was formulated between the numbers of chordwise and spanwise control points needed for good accuracy. This formulation is developed and discussed. Numerical results are given to show the improvement of the computation with the new correction factor

    Fault tectonics and earthquake hazards in parts of southern California

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    The author has identified the following significant results. Four previously unknown faults were discovered in basement terrane of the Peninsular Ranges. These have been named the San Ysidro Creek fault, Thing Valley fault, Canyon City fault, and Warren Canyon fault. In addition fault gouge and breccia were recognized along the San Diego River fault. Study of features on Skylab imagery and review of geologic and seismic data suggest that the risk of a damaging earthquake is greater along the northwestern portion of the Elsinore fault than along the southeastern portion. Physiographic indicators of active faulting along the Garlock fault identifiable in Skylab imagery include scarps, linear ridges, shutter ridges, faceted ridges, linear valleys, undrained depressions and offset drainage. The following previously unrecognized fault segments are postulated for the Salton Trough Area: (1) An extension of a previously known fault in the San Andreas fault set located southeast of the Salton Sea; (2) An extension of the active San Jacinto fault zone along a tonal change in cultivated fields across Mexicali Valley ( the tonal change may represent different soil conditions along opposite sides of a fault). For the Skylab and LANDSAT images studied, pseudocolor transformations offer no advantages over the original images in the recognition of faults in Skylab and LANDSAT images. Alluvial deposits of different ages, a marble unit and iron oxide gossans of the Mojave Mining District are more readily differentiated on images prepared from ratios of individual bands of the S-192 multispectral scanner data. The San Andreas fault was also made more distinct in the 8/2 and 9/2 band ratios by enhancement of vegetation differences on opposite sides of the fault. Preliminary analysis indicates a significant earth resources potential for the discrimination of soil and rock types, including mineral alteration zones. This application should be actively pursued

    Analysis of pseudocolor transformations of ERTS-1 images of Southern California area

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    The author has identified the following significant results. Representative faults and lineaments, natural features on the Mojave Desert, and cultural features of the southern California area were studied on ERTS-1 images. The relative appearances of the features were compared on a band 4 and 5 subtraction image, its pseudocolor transformation, and pseudocolor images of bands 4, 5, and 7. Selected features were also evaluated in a test given students at the University of California, Los Angeles. Observations and the test revealed no significant improvement in the ability to detect and locate faults and lineaments on the pseudocolor transformations. With the exception of dry lake surfaces, no enhancement of the features studied was observed on the bands 4 and 5 subtraction images. Geologic and geographic features characterized by minor tonal differences on relatively flat surfaces were enhanced on some of the pseudocolor images

    Schroedinger Invariance from Lifshitz Isometries in Holography and Field Theory

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    We study non-relativistic field theory coupled to a torsional Newton-Cartan geometry both directly as well as holographically. The latter involves gravity on asymptotically locally Lifshitz space-times. We define an energy-momentum tensor and a mass current and study the relation between conserved currents and conformal Killing vectors for flat Newton-Cartan backgrounds. It is shown that flat NC space-time realizes two copies of the Lifshitz algebra that together form a Schroedinger algebra (without the central element). We show why the Schroedinger scalar model has both copies as symmetries and the Lifshitz scalar model only one. Finally we discuss the holographic dual of this phenomenon by showing that the bulk Lifshitz space-time realizes the same two copies of the Lifshitz algebra.Comment: 5 pages, modified abstract, clarifications added, typos fixed, refs update

    An Evaluation of the Effectiveness of Antibiotic Treatment at a Prebreeding Estrus on Subsequent Reproductive Efficiency

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    An experiment was conducted to evaluate the effectiveness of a douche with an antibiotic formula to improve reproductive efficiency in dairy cows. A total of 102 cows was utilized in the experiment. The 81 Holstein cows were divided into four groups. These groups were untreated cows which had normal post-calving recuperation (N-C), treated cows with had normal post-calving recuperation (N-T), untreated cows which had experienced post-calving complications (M-C), and treated cows which had experienced post-calving complications (M-T). The 20 Jersey cows were divided into treated and untreated groups (N-T and N-C). The treatment consisted of a nitrofurozone-neomycin mixture in a 7 to 1 ratio. The effectiveness of the treatment was evaluated by comparing the interval to first heat, number of prebreeding heats, interval to first service, interval to conception, and conception rates resulting from one and two services. The analysis indicates that there was no difference (P \u3e .05) in days to first heat, number of prebreeding heats, or days to first service. In the Holstein data, the M-T group had the highest conception rate. There was a difference (P \u3c .05) in conception rates between the groups. There was no difference (P \u3e .05) between conception rates of the N-C and N-T groups. However, the trend was for the N-T group to have higher conception rates. In the Jersey data, there were no differences in conception rates between the two groups on first service or first and second service. There was no difference (P \u3e .05) between the groups in number of days to conception for the animal conceiving in two or less services in the Holstein data. However, it is the author\u27s opinion that there would be a difference if the experiment had been continued. This is based on the fact that the majority of cows in group M-C were still open at the conclusion of the experiment. There were no differences (P \u3e .05) between the groups in days to conception in the Jersey cows

    Letter from L. Q. C. Lamar to W. S. Featherston. Undated

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    Letter sent from Marshall County; regarding the relationship between Lamar and Featherston, support for Featherston in U.S. Senate election, presidential appointment, filling appointed mission to Mexico, Colonel Cushman\u27s federal appointment. Envelope.https://egrove.olemiss.edu/ciwar_corresp/1306/thumbnail.jp

    Vortex dynamics

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    Vortex flows of interest to aerodynamicists cover a wide range of scales from a fraction of an inch in boundary layer flows to many feet in wake flows. In many applications these flows are poorly understood and, due to their complexity, present a challenge both analytically and experimentally. Four topics representing the spectrum of experimental and analytical vortex research are presented

    Interaction of cadmium (Cd2+) with a 13-residue polypeptide analog of a putative calcium-binding motif of E-cadherin

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    AbstractPrevious studies from our laboratory have shown that Cd2+ can selectively damage the tight junctions between epithelial cells in culture. Recently, we have obtained evidence suggesting that this effect may involve the interaction of Cd2+ with E-cadherin, a Ca2+-dependent cell adhesion molecule that is localized at the adhering junctions of epithelial cells. To begin to determine whether or not Cd2+ might interact directly with the E-cadherin molecule, we studied the binding of Cd2+ to peptide B, a synthetic, 13-residue polypeptide that corresponds to one of the extracellular Ca2+ binding regions of mouse E-cadherin (also known as uvomorulin). The binding of Cd2+ to peptide B was evaluated by using an equilibrium microdialysis technique and the radioactive isotope 109Cd2+. The effects of the binding on the conformation of the peptide were evaluated by circular dichroism (CD) spectroscopy. The results showed that Cd2+ bound to peptide B, with a maximum of one Cd2+ binding site per molecule and an apparent dissociation constant (Kd) of 640 μM. The binding of Cd2+ was reduced in the presence of excess Ca2+, an effect that was overcome by raising the concentration of Cd2+. Both Cd2+ and Ca2+ caused a shift in the CD spectrum of the peptide. However, the shift produced by Cd2+ was about 3 times the magnitude of that produced by Ca2+. These results indicate that Cd2+ can interact with the Ca2+ binding site on the peptide B molecule and distort the secondary structure of the peptide. These findings are consistent with the hypothesis that E-cadherin may be a direct molecular target for Cd2+ toxicity

    Letter from L. Q. C. Lamar to Col. Van. H. Manning. 10 May 1876

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    Letter sent from Hernando, Mississippi; regarding support of Taylor in senate election, candidates for congressional election and preference for Taylor, Manning\u27s candidacyhttps://egrove.olemiss.edu/ciwar_corresp/1273/thumbnail.jp

    Congressional Record 8 August 1876

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    Includes speech by the Hon. L. Q. C. Lamar (Mississippi) in the House of Representatives, August 2, 1876: Policy of the Repubican Party and the Political Condition of the Southhttps://egrove.olemiss.edu/ciwar_clip/1005/thumbnail.jp
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