Rahul Shukla | Search PubMed

PubMed2006

Cryptosporidium spp. and other zoonotic enteric parasites in a sample of domestic dogs and cats in the Niagara region of Ontario.

To determine the prevalence of Cryptosporidium spp. and other zoonotic enteric parasites in a sample of domestic dogs and cats in the Niagara region, Ontario, 5 of 26 clinics invited by mail survey reported their parasitological findings over 24 months. Stool samples collected by 1 clinic over 68 days were investigated for parasites by using several techniques (fecal concentration, acid-fast staining, and a Cryptosporidium immunoassay). The 5 clinics that provided data indicated Toxocara spp. as the most frequent finding. Parasitological study of 111 stool samples showed a high overall positivity rate in samples from both dogs (40%) and cats (36.6%). Cryptosporidium spp. antigen was detected in 7.4% and 7.3%, Toxocara spp. in 14.2% and 12.2%, and Giardia spp. 7.1% and 2.4% of dog and cat samples, respectively. The high prevalence of zoonotic parasites in the Niagara region is important, and increased awareness of their potential threat to human health is necessary. Additionally, further research into the zoonotic capacity of Cryptosporidium spp. and Giardia spp. is necessary.

Animals↗

PubMed2005

Rate-distortion optimized tree-structured compression algorithms for piecewise polynomial images.

This paper presents novel coding algorithms based on tree-structured segmentation, which achieve the correct asymptotic rate-distortion (R-D) behavior for a simple class of signals, known as piecewise polynomials, by using an R-D based prune and join scheme. For the one-dimensional case, our scheme is based on binary-tree segmentation of the signal. This scheme approximates the signal segments using polynomial models and utilizes an R-D optimal bit allocation strategy among the different signal segments. The scheme further encodes similar neighbors jointly to achieve the correct exponentially decaying R-D behavior (D(R) - c(o)2(-c1R)), thus improving over classic wavelet schemes. We also prove that the computational complexity of the scheme is of O(N log N). We then show the extension of this scheme to the two-dimensional case using a quadtree. This quadtree-coding scheme also achieves an exponentially decaying R-D behavior, for the polygonal image model composed of a white polygon-shaped object against a uniform black background, with low computational cost of O(N log N). Again, the key is an R-D optimized prune and join strategy. Finally, we conclude with numerical results, which show that the proposed quadtree-coding scheme outperforms JPEG2000 by about 1 dB for real images, like cameraman, at low rates of around 0.15 bpp.

Algorithms↗