786 research outputs found
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Multi-media presentation system based on a distributed control network
Control oriented local area networks (COLANs) are being installed in factories at an increasing rate. Traditionally, process control has operated with a master scheduler (computer) monitoring a number of points in a control grid. As the complexity of today's process control needs grow, the need to process information locally increases. Microcontrollers, networked with a master scheduler, can collect data from a locus of points and make decisions as to whether the master needs to be notified or not. By processing data locally, memory and execution time are freed up for the master scheduler. Task implementation becomes modular in nature, resulting in process control software that is easier to write, and maintain. This structure is the basis for COLAN V, a low cost, real-time, distributed control network developed at Oregon State University. COLAN V was used as the foundation for the creation of a multi-media presentation system. Six microcontrollers were networked together to remotely control the operation of projectors, projector screens, and lighting. Based on the application the master scheduler was replaced by a tape player. This allowed the storage of the audio part of the presentation on one track of the tape and the storage of the synchronized control signals on the other track. This distributed control network supplied a low cost solution to a need that was not addressed by the commercial market at any price
The first report of <i>Listeria monocytogenes</i> detected in pinnipeds
The aim of this study was to describe the pathology in seals from which Listeria monocytogenes was isolated and investigate if the lesionsâ nature and severity were related to the phylogeny of isolates. L. monocytogenes was isolated from 13 of 50 (26%) dead grey seal (Halichoerus grypus) pups, six (12%) in systemic distribution, on the Isle of May, Scotland. Similar fatal L. monocytogenes-associated infections were found in a grey seal pup from Carnoustie, Scotland, and a juvenile harbour seal (Phoca vitulina) in the Netherlands. Whole genome sequencing of 15 of the L. monocytogenes isolates identified 13 multilocus sequence types belonging to the L. monocytogenes lineages I and II, but with scant phenotypic and genotypic antimicrobial resistance and limited variation in virulence factors. The phylogenetic diversity present suggests there are multiple sources of L. monocytogenes, even for seal pups born in the same colony and breeding season. This is the first description of L. monocytogenes isolated from, and detected in lesions in, pinnipeds and indicates that infection can be systemic and fatal. Therefore, listeriosis may be an emerging or overlooked disease in seals with infection originating from contamination of the marine environment.</p
The first report of Listeria monocytogenes detected in pinnipeds
The aim of this study was to describe the pathology in seals from which Listeria monocytogenes was isolated and investigate if the lesionsâ nature and severity were related to the phylogeny of isolates. L. monocytogenes was isolated from 13 of 50 (26%) dead grey seal (Halichoerus grypus) pups, six (12%) in systemic distribution, on the Isle of May, Scotland. Similar fatal L. monocytogenes-associated infections were found in a grey seal pup from Carnoustie, Scotland, and a juvenile harbour seal (Phoca vitulina) in the Netherlands. Whole genome sequencing of 15 of the L. monocytogenes isolates identified 13 multilocus sequence types belonging to the L. monocytogenes lineages I and II, but with scant phenotypic and genotypic antimicrobial resistance and limited variation in virulence factors. The phylogenetic diversity present suggests there are multiple sources of L. monocytogenes, even for seal pups born in the same colony and breeding season. This is the first description of L. monocytogenes isolated from, and detected in lesions in, pinnipeds and indicates that infection can be systemic and fatal. Therefore, listeriosis may be an emerging or overlooked disease in seals with infection originating from contamination of the marine environment.</p
Methacarn preserves mucus integrity and improves visualization of amoebae in gills of Atlantic salmon (Salmo salar L.)
Two aqueous fixation methods (modified Davidson's solution and modified Davidson's solution with 2% (w/v) Alcian blue) were compared against two nonâaqueous fixation methods (methacarn solution and methacarn solution with 2% (w/v) Alcian blue) along with the standard buffered formalin fixation method to (a) improve preservation of the mucous coat on Atlantic salmon, Salmo salar L., gills and (b) to examine the interaction between the amoebae and mucus on the gill during an infection with amoebic gill disease. Aqueous fixatives demonstrated excellent cytological preservation but failed to deliver the preservation of the mucus when compared to the nonâaqueousâbased fixatives; qualitative and semiâquantitative analysis revealed a greater preservation of the gill mucus using the nonâaqueous methacarn solution. A combination of this fixation method and an Alcian blue/Periodic acidâSchiff staining was tested in gills of Atlantic salmon infected with amoebic gill disease; lectin labelling was also used to confirm the mucus preservation in the methacarnâfixed tissue. Amoebae were observed closely associated with the mucus demonstrating that the techniques employed for preservation of the mucous coat can indeed avoid the loss of potential mucusâembedded parasites, thus providing a better understanding of the relationship between the mucus and parasite
K\"{a}hler-Einstein metrics on strictly pseudoconvex domains
The metrics of S. Y. Cheng and S.-T. Yau are considered on a strictly
pseudoconvex domains in a complex manifold. Such a manifold carries a complete
K\"{a}hler-Einstein metric if and only if its canonical bundle is positive. We
consider the restricted case in which the CR structure on is
normal. In this case M must be a domain in a resolution of the Sasaki cone over
. We give a condition on a normal CR manifold which it cannot
satisfy if it is a CR infinity of a K\"{a}hler-Einstein manifold. We are able
to mostly determine those normal CR 3-manifolds which can be CR infinities.
Many examples are given of K\"{a}hler-Einstein strictly pseudoconvex manifolds
on bundles and resolutions.Comment: 30 pages, 1 figure, couple corrections, improved a couple example
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Experimental determination of the energy dependence of defect production
The damage function nu(T), i.e., the number of Frenkel pairs as a function of recoil energy is determined for Cu from electron and ion damage-rate measurements. nu(T) shows a plateau at nu = 0.54 which extends up to approx. 7xT/sub d//sup min/. Therefore, simple damage models, such as the modified Kinchin-Pease expression, are inappropriate not only at high recoil energies where stimulated recombination in cascades reduces defect production, but also in the single displacement regime. As a consequence, no simple relation between T/sub d//sup min/ and T/sub d//sup av/ is expected to exist. A procedure is suggested which uses anisotropy measurements in combination with polycrystal electron and ion irradiations to construct absolute damage functions in metals
Giant magnetothermopower of magnon-assisted transport in ferromagnetic tunnel junctions
We present a theoretical description of the thermopower due to
magnon-assisted tunneling in a mesoscopic tunnel junction between two
ferromagnetic metals. The thermopower is generated in the course of thermal
equilibration between two baths of magnons, mediated by electrons. For a
junction between two ferromagnets with antiparallel polarizations, the ability
of magnon-assisted tunneling to create thermopower depends on the
difference between the size of the majority and
minority band Fermi surfaces and it is proportional to a temperature dependent
factor where is the magnon Debye
energy. The latter factor reflects the fractional change in the net
magnetization of the reservoirs due to thermal magnons at temperature
(Bloch's law). In contrast, the contribution of magnon-assisted
tunneling to the thermopower of a junction with parallel polarizations is
negligible. As the relative polarizations of ferromagnetic layers can be
manipulated by an external magnetic field, a large difference results in a magnetothermopower effect. This
magnetothermopower effect becomes giant in the extreme case of a junction
between two half-metallic ferromagnets, .Comment: 9 pages, 4 eps figure
Doping dependence of upper critical field and Hall resistivity in LaFeAsO1-xFx
The electrical resistivity (Rxx) and Hall resistivity (Rxy) of LaFeAsO1-xFx
have been measured over a wide fluorine doping range 0 =< x =< 0.14 using 60 T
pulsed magnets. While the superconducting phase diagram (Tc, x) displays the
classic dome-shaped structure, we find that the resistive upper critical field
(Hc2) increases monotonically with decreasing fluorine concentration, with the
largest Hc2 >= 75 T for x = 0.05. This is reminiscent of the composition
dependence in high-Tc cuprates and might correlate with opening of a pseudo-gap
in the underdoped region. Further, the temperature dependence of Hc2(T) for
superconducting samples can be understood in terms of multi-band
superconductivity. Rxy data for non-superconducting samples show non-linear
field dependence, which is also consistent with a multi-carrier scenario.Comment: 15 pages, 5 figures, Accepted by PR
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