Robust and efficient Fourier-Mellin transform approximations for invariant grey-level image description and reconstruction

International audienceThis paper addresses the gray-level image representation ability of the Fourier-Mellin Transform (FMT) for pattern recognition, reconstruction and image database retrieval. The main practical di±culty of the FMT lies in the accuracy and e±ciency of its numerical approximation and we propose three estimations of its analytical extension. Comparison of these approximations is performed from discrete and ¯nite-extent sets of Fourier- Mellin harmonics by means of experiments in: (i) image reconstruction via both visual inspection and the computation of a reconstruction error; and (ii) pattern recognition and discrimination by using a complete and convergent set of features invariant under planar similarities. Experimental results on real gray-level images show that it is possible to recover an image to within a speci¯ed degree of accuracy and to classify objects reliably even when a large set of descriptors is used. Finally, an example will be given, illustrating both theoretical and numerical results in the context of content-based image retrieval

A robust braille recognition system

Braille is the most effective means of written communication between visually-impaired and sighted people. This paper describes a new system that recognizes Braille characters in scanned Braille document pages. Unlike most other approaches, an inexpensive flatbed scanner is used and the system requires minimal interaction with the user. A unique feature of this system is the use of context at different levels (from the pre-processing of the image through to the post-processing of the recognition results) to enhance robustness and, consequently, recognition results. Braille dots composing characters are identified on both single and double-sided documents of average quality with over 99% accuracy, while Braille characters are also correctly recognised in over 99% of documents of average quality (in both single and double-sided documents)

More about in vitro grape virus symptomatology

An in vitro grafting method adapting the usual “indexing by green grafting” technique (Walter et al., 1990) to in vitro culture conditions was tested. The local grapevine varieties Khamri Tozeur, Akhel Meguergueb, Jerbi Degueche, Asli and Jebbi, infected respectively with infectious degeneration, leafroll, vein mosaic, corky bark and vein necrosis diseases, were used. Virus expression was greater on media having a greater number of nutrients such as the Van Hoof (1974) medium containing 12 macronutrients. On the other hand, the addition of BAP (0.25 mg l-1) to the medium reduced external virus symptoms on newly sprouted axillary shoots. When these shoots were transferred to fresh culture medium supplemented with IBA (0.1 mg l-1), typical and specific symptoms of major virus diseases clearly developed. Re-grafting of axillary shoots on the fragment of an infested clone can be used to overcome difficulties related to corky bark and vein mosaic symptom expression. We also demonstrated that viruses occur in general in mixed infections. The symptoms of a given virus become evident only when favourable conditions to it arise. Our research is still working on reducing the time of detecting virus and virus-like diseases. This is essential for sanitary selection of grapevine plants

Primary pelvic hydatid cyst with sciatic compression

Hydatid cysts are endemic in certain regions of the world and particulary in North Africa. They are usually located in the liver, lung, and spleen, though many uncommon locations have been reported. This is the first report of a child with primary pelvic hydatid disease causing a sciatic compression

Opiate withdrawal syndrome in buprenorphine abusers admitted to a rehabilitation center in Tunisia.

Background: Illicit use of high dosage buprenorphine has been well documented in several countries, including Tunisia. Objectives: The aim of this survey is to assess the buprenorphine withdrawal syndrome time course, and how it may be affected by the population characteristics among subjects admitted to a rehabilitation center in Tunisia. Methods: A prospective research has permitted study of the socio-demographic characteristics and assessment of buprenorphine withdrawal syndrome among 32 subjects admitted for buprenorphine dependence by using the clinical opiate withdrawal scale. An ANOVA was conducted to examine the effect of different factors on the withdrawal scores. Results: 32 subjects were included. Among them 30 were males, 27 had been injecting buprenorphine, 16 were poly-drug abusers and 2 had a history of mental disorders. Buprenorphine withdrawal syndrome was of a mild intensity and had a delayed onset. Withdrawal mean scores varied between 0 and 9, and maximum values were reached at day 21. These scores varied significantly over time (p<0,001). The sex v time interaction and the mode of consumption of buprenorphine had significant effects on the withdrawal scores (p<0,001). The poly-drug consumption and the history of mental disorders did not have any significant effect on the withdrawal scores. Conclusion: This study has permitted description of buprenorphine withdrawal syndrome among patients going through a detoxification treatment at a rehabilitation center. Understanding this syndrome would help elaborate effective and suitable buprenorphine dependence management plans

LAL Regulators SCO0877 and SCO7173 as Pleiotropic Modulators of Phosphate Starvation Response and Actinorhodin Biosynthesis in Streptomyces coelicolor

LAL regulators (Large ATP-binding regulators of the LuxR family) constitute a poorly studied family of transcriptional regulators. Several regulators of this class have been identified in antibiotic and other secondary metabolite gene clusters from actinomycetes, thus they have been considered pathway-specific regulators. In this study we have obtained two disruption mutants of LAL genes from S. coelicolor (Δ0877 and Δ7173). Both mutants were deficient in the production of the polyketide antibiotic actinorhodin, and antibiotic production was restored upon gene complementation of the mutants. The use of whole-genome DNA microarrays and quantitative PCRs enabled the analysis of the transcriptome of both mutants in comparison with the wild type. Our results indicate that the LAL regulators under study act globally affecting various cellular processes, and amongst them the phosphate starvation response and the biosynthesis of the blue-pigmented antibiotic actinorhodin. Both regulators act as negative modulators of the expression of the two-component phoRP system and as positive regulators of actinorhodin biosynthesis. To our knowledge this is the first characterization of LAL regulators with wide implications in Streptomyces metabolism

Target genes and structure of the direct repeats in the DNA-binding sequences of the response regulator PhoP in Streptomyces coelicolor

Expression of genes belonging to the pho regulon in Streptomyces coelicolor is positively regulated (as shown by comparing the wild-type and a ΔphoP mutant) by binding of the response regulator PhoP to 11-nt direct repeats (DRus). These sequences have been found in over 100 genes of Streptomyces coelicolor; 20 of them were cloned and the binding of PhoPDBD to most of their promoters has been shown by electrophoretic mobility shift assays. Deletion experiments showed that at least two DRus are required for proper binding of PhoPDBD. Deletion of 1 nt leaving a 10-nt direct repeat reduced drastically binding of PhoPDBD. Three different types of operators have been identified. Complex operators (class III) contain up to six DRus, some of them with poor conservation of the 11-nt consensus sequence, which however were protected by PhoPDBD in footprinting analyses. A cooperative binding of PhoPDBD molecules initiated at conserved core DRus appears to be the mechanism involved in binding of several PhoPDBD monomers to those complex operators. The information theory-based model that incorporates the positive or negative contribution to the binding of PhoPDBD of adjacent sequences has been used to deduce the structure of PHO boxes and the relevance of each DRu