Edgedetection using wavelet transform and neural networks

The method exposed in this paper represents a new edge-detection tool of a grey-level image by the cooperation of two technics : wavelet decomposition and neural networks . The first part recalls the necessary background on mono and bidimensional wavelet decomposition and their main properties . The difficult phase of the algorithm lies in the optimal recomposition of différent resolutions, in the aim to obtain thin and noiseless edges . This work is given to a neural network which constitutes the object of the second part. The main interest of this new method is to give good resuits with images whose caracteristics are completly différent, without to modify any parameters .La méthode présentée dans cet article, constitue un nouvel outil d'extraction des contours d'une image en niveaux de gris, par coopération de techniques: décomposition en ondelettes et réseaux neuromimétiques. La première partie est consacrée aux rappels nécessaires quant au formalisme de la décomposition en ondelettes, ainsi que ses principales propriétés. La phase délicate de l'algorithme réside dans la recomposition optimale des différentes résolutions, afin d'obtenir des contours fins et sans bruit. Cette tâche est avantageusement confiée à un réseau de neurones, objet de la deuxième parti

A Built-In Strategy for Containment of Transgenic Plants: Creation of Selectively Terminable Transgenic Rice

Plant transgenic technology has been widely utilized for engineering crops for trait improvements and for production of high value proteins such as pharmaceuticals. However, the unintended spreading of commercial transgenic crops by pollination and seed dispersal is a major concern for environmental and food safety. Simple and reliable containment strategies for transgenes are highly desirable. Here we report a novel method for creating selectively terminable transgenic rice. In this method, the gene(s) of interest is tagged with a RNA interference cassette, which specifically suppresses the expression of the bentazon detoxification enzyme CYP81A6 and thus renders transgenic rice to be sensitive to bentazon, a herbicide used for rice weed control. We generated transgenic rice plants by this method using a new glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Pesudomonas putida as the gene of interest, and demonstrated that these transgenic rice plants were highly sensitive to bentazon but tolerant to glyphosate, which is exactly the opposite of conventional rice. Field trial of these transgenic rice plants further confirmed that they can be selectively killed at 100% by one spray of bentazon at a regular dose used for conventional rice weed control. Furthermore, we found that the terminable transgenic rice created in this study shows no difference in growth, development and yield compared to its non-transgenic control. Therefore, this method of creating transgenic rice constitutes a novel strategy of transgene containment, which appears simple, reliable and inexpensive for implementation

Contribution of neural network to an edge-detection tool using wavelets transformation

The method exposed in this paper represents a new edge-detection tool of a greylevel image by the cooperation of two technics : wavelet decomposition and neural networks. The first part recalls the necessary background on mono and bidimensional wavelet decomposition and their main properties. The difficult phase of the algorithm lies in the optimal recomposition of different resolutions, in the aim to obtain thin and noiseless edges. This work is given to a neural network which constitutes the object of the second part The main interest of this new method is to give good results with images whose caracteristics are completly different, without to modify any parametersLa méthode présentée dans cet article, constitue un nouvel outil d'extraction des contours d'une image en niveaux de gris, par coopération de techniques : décomposition en ondelettes et réseaux neuromimétiques. La première partie est consacrée aux rappels nécessaires quant au formalisme de la décomposition en ondelettes, ainsi que ses principales propriétés. La phase délicate de l'algorithme réside dans la recomposition optimale des différentes résolutions, afin d'obtenir des contours fins et sans bruit. Cette tâche est avantageusement confiée à un réseau de neurones, objet de la deuxième partie. L'attrait majeur de cette nouvelle technique, est sa capacité à traiter correctement des images aux caractéristiques très différentes, sans avoir à modifier de paramètre

Dicoumarol relieves serum withdrawal-induced G0/1 blockade in HL-60 cells through a superoxide-dependent mechanism

13 páginas, 10 figuras, 1 tabla.This work was set to study how dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G0/1 after serum deprivation. However, when cells were treated with 5 μM dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of dicoumarol. However, N-acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and dicoumarol still inhibited G0/1 blockade in the presence of ES936. We demonstrate that dicoumarol inhibits the normal blockade in G0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of dicoumarol to elucidate cellular processes involving oxidoreductases.Supported by Grants No. BMC2002-01078 (Spanish Ministerio de Educación y Cultura and Ministerio de Ciencia y Tecnología) and CVI-276 (Junta de Andalucía). R.I.B. acknowledges financial support by the Spanish Ministerio de Educación y Cultura, CVI-276, and Instituto Danone. C.G.D. and M.C.C.-P. were supported by CVI-276. N.F. was granted by the French Association pour la Recherche sur le Cancer and by Junta de Andalucía.Peer reviewe

Neuropsychological assessment in pediatric epilepsy surgery: A French procedure consensus

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