Image-based approach

The number and range of applications is increasing, particularly for image-based approaches. It is expected that the number of practical field-deployable systems, rather than research systems, will increase rapidly in the near future for three reasons (1) availability of new, powerful mobile technology such as mobile camera phones, (2) the worsening taxonomic impediment and (3) an increasing acceptance of ATI as a viable tool. 

At the end of the 1980s and early 1990s, first experiments were carried out to combine fluorescence lifetime measurements with imaging using both time domain [1-4] and frequency domain [5-7] based approaches. This chapter will deal exclusively with time domain based fluorescence lifetime imaging methods. For the frequency domain based methods, refer Chapter 2. 

Feldmann and others have developed a series of teaching tools for macromolecular structure using color-coded molecular graphics-derived images 24 28). Connolly and others have improved upon this approach by clearly showing which portions of the protein surface are indeed accessible to a water molecule, as opposed to those portions which are inaccessible, such as in clefts, etc 27). Images based on the Connolly methods directly show those regions of the protein surface which can be expected to interact with other molecules. It provides immediate, comprehensible information about steric complimentarity. 

Here we describe the construction and use of adenoviruses to express lucif-erase- or GFP-fusion proteins for high-throughput cell-based screens. We constructed adenoviruses that express a cyclin Bl-luciferase reporter protein or unmodified luciferase. This enabled us to screen for small molecules that specifically up-regulated levels of the cyclin B 1-luciferase fusion protein without affecting luciferase. A similar approach was used to construct adenoviruses that express cyclin A-GFP or cyclin Bl-GFP fusion proteins. These viruses were used in an imaging-based screen to identify small molecules that specifically upregulated these proteins or altered their subcellular localization. 

Amongst the different oblivious invisible watermarking schemes proposed in the literature, an important category is that of block-based techniques, which partition the host image into non-overlapping blocks, and insert the watermark into individual blocks of the host image [14, 9, 10, 11, 15, 16]. A block-based approach can be convenient in terms of simplicity and lack of computational overhead. However, a number of block-based methods proposed in the literature suffer from a critical vulnerability, which is that of the block-wise... 

By linking technological advances in chemical imaging with a science-based approach to using these new capabilities, it is likely that fundamental breakthroughs in our understanding of basic chemical processes in biology, the environment, and man-made creations will be achieved. 

While the physics-based approach provides detections where the clutter matched filter does not, it is also important to note the nature of the false alarms generated by each method. The clutter-matched filter is essentially a projection operator and is susceptible to false alarms on pixels with large spectral magnitude i.e., bright pixels). The physics-based approach tends to false alarm on background materials not well characterized and on sensor artifacts. The latter is because the detection is in the native radiance space of the image and in the presence of miscalibration or artifacts, the predicted signatures will not match well with the measurement. 

A. V. Poliakov, E. Albright, D. Corina, G. Ojemann, R. F. Martin, and J. F. Brinkley 2001. Server-based approach to web visualization of integrated 3-D medical image data. In Proceedings, American Medical Informatics Association Fall Symposium. Washington, DC AMIA. pp. 533-537. 

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