856 research outputs found
Molecular Genetic Typing of Staphylococcus aureus from Cows, Goats, Sheep, Rabbits and Chickens
End of project reportsS. aureus can also cause a number of infections in animals such as tick-associated pyaemia in lambs, staphylococcosis in rabbits, septicaemia, abscesses and chondronecrosis in chickens and pneumonia and osteomyelitis complex in turkeys. S. aureus is the most frequent cause of bovine mastitis, a disease that is of economic importance worldwide (Beck et al., 1992). Typically staphylococcal mastitis is chronic in nature, with subclinical mastitis being the most common form
Extended atmospheres of outer planet satellites and comets
In the third year of this 3-year project, research accomplishments are discussed and related to the overall objective. In the area of the distribution of hydrogen in the Saturn system, new Voyager UVS data have been discovered and are discussed. The data suggest that both Titan's hydrogen torus and Saturn's hydrogen corona play a major role in the circumplanetary gas source. Modeling analysis of this new data establishes a strong basis for continuing studies to be undertaken in a new NASA-sponsored project. In the area of the cometary atmospheres, observational data for H, O, C, and OH acquired with the Pioneer Venus Orbiter are evaluated and preliminary modeling analysis for some of the hydrogen Lyman-alpha data is presented. In addition, the importance of collisional thermalization in spatial properties and structure of the inner and extended comae of comets has been demonstrated using the recently developed particle trajectory model. The successful simulation by this model of the hydrogen Lyman-alpha image for Comet Kohoutec near perihelion, an extreme case for collisional thermalization, is particularly noteworthy
Extended atmospheres of comets and outer planet-satellite systems
For the hydrogen coma of comet P/Halley, both a Lyman-alpha image and extensive Lyman-alpha scan data obtained by the Pioneer Venus Orbiter Ultraviolet spectrometer as well as H-alpha ground-based spectral observations obtained by the University of Wisconsin Space Physics Group were successfully interpreted and analyzed with our Monte Carlo particle trajectory model. The excellent fit of the model and the Halley data and the water production rate determined near perihelion (9 Feb. 1986) from 13 Dec. 1985 to 13 Jan. 1986 and from 1 Feb. to 7 Mar. 1986 are discussed. Studies for the circumplanetary distribution of atomic hydrogen in the Saturn and Neptune systems were undertaken for escape of H atoms from Titan and Triton, respectively. The discovery of a new mechanism which can dramatically change the normal cylindrically symmetric distribution of hydrogen about the planet is discussed. The implications for the Titan-Saturn and Triton-Neptune are summarized
A modeling analysis program for the JPL table mountain Io sodium cloud data
Research in the third and final year of this project is divided into three main areas: (1) completion of data processing and calibration for 34 of the 1981 Region B/C images, selected from the massive JPL sodium cloud data set; (2) identification and examination of the basic features and observed changes in the morphological characteristics of the sodium cloud images; and (3) successful physical interpretation of these basic features and observed changes using the highly developed numerical sodium cloud model at AER. The modeling analysis has led to a number of definite conclusions regarding the local structure of Io's atmosphere, the gas escape mechanism at Io, and the presence of an east-west electric field and a System III longitudinal asymmetry in the plasma torus. Large scale stability, as well as some smaller scale time variability for both the sodium cloud and the structure of the plasma torus over a several year time period are also discussed
One Bold Experiment
A monthly exchange of letters from 165 seventh graders in an arts school in Charleston, South Carolina to similar classrooms in 16 countries around the world proved to be the writing project that captured every state writing standard all at once -- brainstorming, writing, collaboration, analysis, proofreading, and re-writing. This one activity was the highlight of the year for each student as letters and gifts poured in from every continent September to June. This was truly a teacher\u27s dream come true
Estate Records and the Making of the Irish Landscape: An Example from County Tipperary
Some of the better estate maps of 18th-century Ireland – especially those
produced by the French school of land-surveyors – have recently
received welcome attention from a number of Irish geographers. There
are extensive areas of 18th and of early 19th-century Ireland, however,
which are either not covered, or only poorly served, in relation to such
rich cartographic source-materials. As Andrews has noted 'most Irish
land-surveyors of the pre-Ordnance period concentrated on simple
outline maps of tenement boundaries and were both niggardly and
arbitrary in their choice of interior detail. Since maps do constitute the
most important single body of evidence for the historical geographer, his
task is further frustrated in the Irish context by the loss of quite a
number of estate map collections which seem to have disappeared
without trace. The objective of this paper, therefore, is simply to draw
geographers' attention to the diverse range of estate documentary
material – other than estate maps – which can either provide important
clues towards the explanation of territorial patterns illustrated on
contemporary estate atlases or which – as in this example – can be used
in the absence of such maps to build up at least a general picture of the
evolution of the rural landscape
Computing regularities in strings
Regularities in strings model many phenomena and thus form the subject of extensive mathematical studies . Perhaps the most conspicuous regularities in strings are those that manifest themselves in the form of repeated subpatterns. In this paper, we study several forms of regularities of strings, that is, repeats, multirepeats, repetitions and runs. We present their similarities and differences by discussing their forms and properties and we explore the existing computation algorithms. We also discuss several data structures useful for computing regularities
An eigenvalue distribution derived ‘Stability Measure’ for evaluating Minimum Variance portfolios
Secondary instability of salt sheets
In the presence of a vertically varying horizontal current (background shear), the salt-fingering instability is supplanted by the salt-sheet instability. Previous direct numerical simulation (DNS) experiments on salt sheets revealed that flow becomes turbulent via secondary instabilities. We call these instabilities zig-zag and tip modes. Here, we investigate the physics of these modes using linear normal mode stability analysis. As the primary instability (salt-sheet instability) grows, the zig-zag mode emerges, which denotes undulation of growing salt sheets at the center of fingering regions. This mode is shown to be an extension of secondary instability of unsheared two-dimensional salt-fingering. The zig-zag mode is amplifed almost uniformly at all horizontal wavelengths exceeding O(1 m). This mechanism may, therefore, account for the tilted laminae seen in shadowgraph images of microstructure in salt fingering regions. Subsequently, the tip mode appears at the tips of undulating salt sheets introducing streamwise dependence that leads the flow into turbulent regime
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