MOTIVATION: One of the most interesting features of genomes (both coding and non-coding regions) is the presence of relatively short tandemly repeated DNA sequences known as tandem repeats (TRs). We developed a new PC-based stand-alone software analysis program, combining sequence motif searches with keywords such as organs, tissues, cell lines or development stages for finding exact, inexact and compound, TRs. Tandem Repeats Analyzer 1.5 (TRA) has several advanced repeat search parameters/options over other repeat finder programs as it does not only accept GenBank, FASTA and expressed sequence tag (EST) sequence files but also does analysis of multifiles with multisequences. Advanced user-defined parameters/options let the researchers use different motif lengths search criteria for varying motif lengths simultaneously. The outputs show statistical results to be evaluated by the user. The discovery of TRs in ESTs could be useful for both gene mapping and association studies and discovering TRs located in coding regions of important genes that are expressed under various conditions of environment, stress, organ, tissue and development stage. RESULTS: In this paper, we demonstrated applications of TRA using 175 899 ESTs sequences for three Arabidopsis spp. downloaded from GenBank. The EST-SSRs/ESTs ratios were found 43.1%, 15.3% and 2.34% in A.lyrata, A.thaliana and A.halleri, respectively. Analysis revealed that organs, tissues and development stages possessed different amounts of repeats and repeat compositions. This indicated that the distribution of TRs among the tissues or organs may not be random differing from the untranscribed repeats found in genomes. AVAILABILITY: The program can be obtained free by anonymous FTP from ftp.akdeniz.edu.tr/Araclar/TRA.

An image restoration model is given to restore images blurred by a random medium. The overall distortion process caused by the random medium is represented by a stochastic point spread function. To estimate the original images degraded by this model, two restoration algorithms are formulated based on the Wiener filter and the constrained least-squares filter. Computer simulations are included to compare the performances of the proposed algorithms with the conventional ones.>