Regularity and identification of Generalized Multifractional Gaussian Processes

International audienceIn this article a class of multifractal processes is introduced, called Generalized Multifractional Gaussian Process (GMGP). For such multifractional models, the Hurst exponent on the celebrated Fractional Brownian Motion is replaced by a function, called the multifractional function, which may be irregular. The main aim of thi paper is to show how to identify irregular multifractional functions in the setting of GMGP. Examples of discontinuous multiractional functions are also given

Classification of Texture Images using Multi-scale StatisticalEstimators of Fractal Parameters

We present a new method of fractal-based texture analysis, using the multi-scale fractional Brownian motion texture model, and a new parameter, in-termittency. The intermittency parameter p describes a degree of presence of the textural information: a low value of p implies a very lacunar texture. The multi-scale fractional Brownian motion model allows to construct multi-regime textures in the frequency domain. Adding intermittency to this model, we compose the intermittent multi-scale fractional Brownian motion model: the Hurst and intermittency parameters of such processes are functions H(l) and p(l) depending on a scale l. The texture is thereby seen as the fusion of structures and details. The structure of the texture is analyzed with the large values of l, corresponding to the low frequency content of the texture. The details of the texture are analyzed with the small values of l, related to the high frequency content of the texture. The texture is then characterized by all the estimated values of H(l) and p(l), for all the scales l of analysis. The method allows a multi-frequency analysis, permitting the choice of sig-nificant scales in a classification task. An application to the classification of corn silage texture images, for which the low frequency content is determin-ing, is proposed. Keywords. Texture, fractal, multi-scale and multi-frequency analysis, multi-scale fractional Brownian motion, intermit-tency, Hurst parameter, statistical estimators, self-similarity, image classification.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers

This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allergy are reviewed: applications, exposure scenarios, legislation, patch testing problems, frequency of sensitization, relevance of positive patch test reactions, clinical pattern of allergic contact dermatitis from formaldehyde, prognosis, threshold for elicitation of allergic contact dermatitis, analytical tests to determine formaldehyde in products and frequency of exposure to formaldehyde and releasers. The frequency of contact allergy to formaldehyde is consistently higher in the USA (8-9%) than in Europe (2-3%). Patch testing with formaldehyde is problematic; the currently used 1% solution may result in both false-positive and false-negative (up to 40%) reactions. Determining the relevance of patch test reactions is often challenging. What concentration of formaldehyde is safe for sensitive patients remains unknown. Levels of 200-300 p.p.m. free formaldehyde in cosmetic products have been shown to induce dermatitis from short-term use on normal skin

Successful surgical excision of primary right atrial angiosarcoma

Primary cardiac angiosarcoma is a rare and aggressive tumor with a high incidence of metastatic spread (up to 89%) at the time of diagnosis, which restricts the indication for surgical resection to a small number of patients. We report the case of a 50-year old Caucasian woman with non-metastatic primary right atrial angiosarcoma, who underwent successful surgical excision of the tumor (with curative intent) and reconstruction of the right atrium with a porcine pericardial patch. However, after a symptom-free survival of five months the patient presented with bone and liver metastases without evidence of local tumor recurrence