Adaptive and Blind Audio Watermarking Algorithm Based on Chaotic Encryption in Hybrid Domain

An adaptive and blind audio watermarking algorithm is proposed based on chaotic encryption in discrete cosine transform (DCT) and discrete wavelet transform (DWT) hybrid domain. Since human ears are not sensitive to small changes in the high-frequency components of the audio media, the encrypted watermark can be embedded into the audio signal according to the special embedding rules. The embedding depth of each audio segment is controlled by the overall average amplitude to effectively improve the robustness and imperceptibility. The watermark is encrypted by a chaotic sequence to improve the security of watermark, so only users who hold the correct key can accurately extract the watermark without the original audio signal. Experimental results show that the proposed algorithm has larger capacity, higher imperceptibility, better security, and stronger robustness when combating against signal-processing attacks than the involved audio watermarking algorithms in recent years.

Thin Section Staining of Epithelial Cells to Reveal Bound Carbohydrate

A complex of OsVI in combination with the ligand TEMED(Tetramethylethylenediamine) has been shown to be specific for glycol groups of sugar. This stain has been successfully applied to thin sections: The same staining patterns were revealed in type 1 collagen in both isolated and embedded material (Fig.1). Special embedding techniques designed to minimize the perturbation of the specimen were required. In the present preliminary study these methods (and the specific stain) have been applied to thin sections of epithelial cells and have given information on the intracellular distribution of bound carbohydrates. Other methods for investigations of this nature are at lower resolution and do not allow for discrimination of sugars at membrane surfaces of closely adjacent organelles.

Wafer Embedment to Facilitate Light Microscope Selection of Specimens for Ultrathin Sectioning

An unfortunate consequence of the high magnification achieved in electron microscopy is the inability to scan large areas of tissue or locate structures which are small and of infrequent occurrence. The standard procedure is to section repeatedly, hoping that an area of interest will be encountered. However, this time-consuming practice can be avoided by the use of a special embedding platform which permits the embedment of tissue for examination by light microscopy prior to sectioning.Aldehyde-fixed tissues are cut into 10μm sections with a Vibratome or into 20-30μm sections with a Sorvall TC-2 tissue sectioner. At this point optimal sections may be selected on the basis of a particular morphological feature, for which a light methylene blue or Alcian blue stain may be employed; or selection may be based upon activity of a cytochemical enzyme stain, particularly one which involves 3,3'-diaminobenzidine (DAB).