1,721,205 research outputs found
Shading correction and calibration in bacterial fluorescence measurement by image processing system
No full textAn image processing system with applications in bacterial (immuno-)fluorescence measurement has been developed. To reach quantitative results, correction for non-uniformities in system sensitivity, both as a function of time (calibration for drifts) and as a function of image coordinates (shading correction), is essential. Both problems can be handled simultaneously by acquiring images of a uniformly fluorescent, solid standard as a reference image. To measure bacterial fluorescence, the average fluorescence intensity of isolated areas of interest (the bacteria) is computed, and corrected using the reference images. Two shading correction methods are theoretically and experimentally compared: direct averaging in the corrected image, and (weighted and unweighted) averaging using the raw image and a separate shading image to determine the weights and correct for shading during the averaging. The latter method proved computationally 3.5-6.5 times faster on average and reduced propagation of truncation errors during computation, resulting in 40% less noise, for 8-bits/pixel images.
Hyperconnectivity, Attribute-Space Connectivity and Path Openings: Theoretical Relationships
No full textIn this paper the relationship of hyperconnected filters with path openings and attribute-space connected filters is studied. Using a recently developed axiomatic framework based on hyperconnectivity operators, which are the hyperconnected equivalents of connectivity openings, it is shown that path openings are a special case of hyperconnected area openings. The new axiomatics also yield insight into the relationship between hyperconnectivity and attribute-space connectivity. It is shown any hyperconnectivity is an attribute-space connectivity, but that the reverse is not true.</p
Nonlinear Dynamics, Chaos-theory, and the “Sciences of Complexity”: Their Relevance to the Study of the Interaction between Host and Microflora
Get PDFTheoretical and experimental studies of various biomedical systems, including heart, brain, immune system, and many ecosystems, have shown that many of these systems may be described in terms of nonlinear dynamics. Two important consequences of this nonlinear dynamical behaviour are irreversibility and unpredictability, due to the chaotic behaviour this type of system may exhibit. Another trend in modern science (often named “the sciences of complexity”) deals with the often complex or chaotic collective behaviour of systems made up of large numbers of relatively simple entities. Very often such systems exhibit nonlinear dynamical behaviour. Many such complex and nonlinear systems have been studied successfully using computer simulation techniques.
It is proposed that, as has been demonstrated for the immune system, the intestinal microbial ecosystem may be viewed as such a complex system governed by nonlinear dynamical equations. A discussion of techniques available for the study of such systems is given, with a special emphasis on computer simulation. Finally, the results of a pilot study using computer simulation of the interaction between the anaerobic and aerobic compartments of the microflora within a simple geometric model of the small and large intestine are presented.
Quantitating single colour fluorescence; immunofluorescence (IF) and fluorescence in situ hybridization (FISH).
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Some practical considerations for the development of image analysis applications in microbiology: ensuring software and data durability
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