Optimal texture image segmentation using multiple matched transforms

This paper deals with a new method for texture analysis based on the Karhunen Loeve Transform (KLT). KLT allows an optimal and compact description of textures. During a training step, filter sets matched to each analyzed texture are computed . Automatic image segmentation is performed classifying each pixel according ta its texture attribute vector. A pixel belongs to the class corresponding to the filter set which tends ta an optimal share out of its "texture energy ". The decision rule is based on the Maximum Likelihood principle . The critical problem of choising the most relevant texture attributes is automaticaly solved by the proposed method. Thus, different texture classes can be processed.Dans cet article nous présentons une méthode statistique d'analyse de textures fondée sur la Transformée de Karhunen-Loeve (T.K.L.). La TKL permet une description compacte et optimale de la texture. Des bancs de filtres adaptés à chaque texture de l'image (filtres RIF) sont déterminés durant une phase d'apprentissage. La segmentation automatique d'une image de texture est réalisée par classement automatique des pixels sur la base des valeurs prises par leur vecteur d'attributs de texture. Le banc de filtres qui assure une répartition optimale de «l'énergie de texture» dans le voisinage du pixel considéré détermine sa classe d'affectatio

Carbonic anhydrase IX is a pH-stat that sets an acidic tumour extracellular pH in vivo

Background Tumour Carbonic Anhydrase IX (CAIX), a hypoxia-inducible tumour-associated cell surface enzyme, is thought to acidify the tumour microenvironment by hydrating CO2 to form protons and bicarbonate, but there is no definitive evidence for this in solid tumours in vivo. Methods We used 1H magnetic resonance spectroscopic imaging (MRSI) of the extracellular pH probe imidazolyl succinic acid (ISUCA) to measure and spatially map extracellular pH in HCT116 tumours transfected to express CAIX and empty vector controls in SCID mice. We also measured intracellular pH in situ with 31P MRS and measured lactate in freeze-clamped tumours. Results CAIX expressing tumours had 0.15 pH-unit lower median extracellular pH than control tumours (pH 6.71 tumour vs pH 6.86 control, P = 0.01). Importantly, CAIX expression imposed an upper limit for tumour extracellular pH at 6.93. Despite the increased lactate concentration in CAIX-expressing tumours, 31P MRS showed no difference in intracellular pH, suggesting that CAIX acidifies only the tumour extracellular space. Conclusions CAIX acidifies the tumour microenvironment, and also provides an extracellular pH control mechanism. We propose that CAIX thus acts as an extracellular pH-stat, maintaining an acidic tumour extracellular pH that is tolerated by cancer cells and favours invasion and metastasis.We are grateful for the support of CRUK [grant number C14303/A17197], the Breast Cancer Research Foundation, the Royal Society, Worldwide Cancer Research and the European Research Council [SURVIVE: 723397]. JP-T and SC received support from the Spanish Ministry of Economy and Competitiveness SAF2014-23622

CARI'96 : actes du 3ème colloque africain sur la recherche en informatique = CARI'96 : proceedings of the 3rd African conference on research in computer science

Dans cet article, nous présentons une méthode de segmentation hiérarchique de textures fondée sur une décomposition en ondelettes de l'image. Une segmentation grossière est effectuée au niveau de résolution le plus élevé à partir de prototypes de chaque classe de texture déterminés avec un classificateur flou. Une analyse de voisinage permet ensuite de créer une classe de pixels ambigus. La segmentation initiale est progressivement affinée en reportant la prise de décision pour les pixels ambigus au niveau de résolution de l'image originale. (Résumé d'auteur

Pharmacokinetic of tumor FDG uptake in subcutaneous and orthotopic preclinical models of breast cancer - Influence of administration route

International audienc

Assessment of metabolic changes in the striatum of a rat model of parkinsonism: An in vivo 1H MRS study

Degeneration of the dopaminergic neurons of the substantia nigra pars compacta in Parkinson's disease induces an abnormal activation of the glutamatergic neurotransmission system within the basal ganglia network and related structures. The aim of this study was to use proton MRS to show metabolic changes in the striatum of 6-hydroxydopamine-lesioned rats, a rodent animal model of Parkinson's disease. Animals were examined before and after extensive lesioning of the nigral dopaminergic neurons and after acute administration of L-3,4-dihydroxyphenylalanine. No significant alterations in glutamate concentrations, assessed by the MR signal dominated by glutamate with minor contributions from glutamine and γ-aminobutyric acid, could be measured. The total choline/total creatine ratio was found to be reduced in the striatum of the ipsilateral hemisphere. Copyright © 2008 John Wiley & Sons, Ltd

SUMCASTEC_190426_NA_PLUMEE19_Conference paper_.pdf_Limoges_T. Provent_Public_NA

Paper entitled "Continuous Cell Sorting by High Frequencies Dielectrophoresis" for the PLUMEE 2019 conference: the French speaking Multidisciplinary conference on Material, Environment and Electronic, April 10-12th, Limoges, France