A Fragile Image Watermarking Scheme in DWT Domain Using Chaotic Sequences and Error-Correcting Codes.

With the rapid development of digital signal processing tools, image contents can be easily manipulated or maliciously tampered with. Fragile watermarking has been largely used for content authentication purposes. This article presents a new proposal for image fragile watermarking algorithms for tamper detection and image recovery. The watermarked bits are obtained from the parity bits of an error-correcting code whose message is formed from a binary chaotic sequence (generated from a secret key known to all legitimate users) and from bits of the original image. Part of the codeword (the chaotic bits) is perfectly known to these users during the extraction phase, adding security and robustness to the watermarking method. The watermarked bits are inserted at specific sub-bands of the discrete wavelet transform of the original image and are used as authentication bits for the tamper detection process. The imperceptibility, detection, and recovery of this algorithm are tested for various common attacks over digital images. The proposed algorithm is analyzed for both grayscale and colored images. Comparison results reveal that the proposed technique performs better than some existing methods.

Enzyme-linked immunosorbent assay and agar gel immunodiffusion assay for diagnosis of equine infectious anemia employing p26 protein fused to the maltose-binding protein.

A codon-optimized equine infectious anemia virus p26 gene was fused to a maltose-binding protein (MBP) and expressed in Escherichia coli for use as an antigen in agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA) for diagnosis of equine infectious anemia. An analysis of analytical sensitivity and specificity showed that the antigen MBP-p26rec reacted positively with a reference World Organization for Animal Health serum and demonstrated no cross-reaction against sera from vaccinated animals in either test. The diagnostic characteristics were evaluated and presented excellent values. The AGIDrec showed 100% sensitivity and specificity, and the ELISArec showed 100% sensitivity and 99.64% specificity. In addition, MBP-p26rec was stabile after three years of storage at 4 °C, maintaining its immunoreactivity.

Long-term effects of drenches with condensed tannins from Acacia mearnsii on goats naturally infected with gastrointestinal nematodes.

In this study, the long-term effects of exposure to a drench containing condensed tannins (CTs) from Acacia mearnsii on gastrointestinal nematodes in goats were investigated. Male cross-bred Anglo-Nubian goat kids between 3 and 5 months of age were dewormed at the beginning of the experiment. The goat kids were divided into one group that received weekly 24 g oral doses of A. mearnsii bark extract dissolved in water containing 16.7% CTs (GCT group, n = 8) and a second group that did not receive CTs (GC group, n = 8). All of the animals were kept in an Andropogon gayanus pasture and grazed with a herd of 100 naturally infected adult goats. Each animal was supplemented daily with 200 g of a concentrated mixture containing 18% crude protein. Fecal egg counts (FECs) were performed weekly for 192 days, and weight measurements and blood collections were done at two-week intervals in this period. The packed cell volume of the blood was calculated, and the plasma was used to determine the total protein, albumin, and glucose concentrations. After 192 days, the animals were slaughtered and the carcasses evaluated, with nematodes harvested for identification and counting. The FECs of the animals treated with CTs from A. mearnsii (GCT group) remained lower than the FECs of the control group animals for the majority of the first half of the experimental period. An observed increase in the FECs for both groups coincided with increased rainfall in the region where the experiment was conducted. The worm burden, scrotal circumference, carcass weight, leg circumference, carcass size and blood analysis were not significantly different between the groups. The packed cell volume (PCV) was constant in all of the animals throughout the experiment. In conclusion, repeated and prolonged treatment of goats with CTs from A. mearnsii helped to maintain low FECs in a period of low challenge but did not reduce nematode infections in the goats.