Search results for "Subtraction"
showing 10 items of 112 documents
Déterminisme du pouvoir protecteur de Fusarium oxysporum : recherche de gènes impliqués dans l'interaction protectrice avec la tomate
2007
Fusarium oxysporum is a common soil borne fungus, well represented in every type of soils, throughout the world. This species includes pathogenic strains inducing severe diseases in many crops and strains able to protect a plant against the infection by a pathogenic strain. The protective strains are not only non pathogenic strains isolated from suppressive soils but also pathogenic strains applied to a non host plant. The protective capacity of these strains is mainly based on mechanisms of competition and induced resistance of the plant The main objective of this work was to identify fungal genes involved in the protective capacity of these strains and associated to the elicitation of pla…
Determination of absolute internal conversion coefficients using the SAGE spectrometer
2016
A non-reference based method to determine internal conversion coefficients using the SAGE spectrometer is carried out for transitions in the nuclei of 154Sm, 152Sm and 166Yb. The Normalised-Peak-to-Gamma method is in general an efficient tool to extract internal conversion coefficients. However, in many cases the required well-known reference transitions are not available. The data analysis steps required to determine absolute internal conversion coefficients with the SAGE spectrometer are presented. In addition, several background suppression methods are introduced and an example of how ancillary detectors can be used to select specific reaction products is given. The results obtained for …
A2Ba: Adaptive Background Modelling for Visual Aerial Surveillance Conditions
2015
International audience; Background modelling algorithms are widely used to define a part of an image that most time remains stationary in a video. In surveillance tasks, this model helps to recognize those outlier objects in an area under monitoring. Set up a background model on mobile platforms (UAVs, intelligent cars, etc.) is a challenging task due camera motion when images are acquired. In this paper, we propose A2Ba, a robust method to support instabilities caused by aerial images fusing different information about image motion. We used frame difference as first approximation, then age of pixels is estimated. This latter gives us an invariability level of a pixel over time. Gradient di…
A Bottleneck Model of Imaging Systems for Digital Angiocardiography
1988
Some ten years ago, the performance of real-time digital subtraction angiocardiography was demonstrated for the first time [1]. Subtraction became in the years after 1980 nearly synonymous with digital angiography [2–4]. This image enhancement technique was certainly very efficient in paving the way for the digital approach to imaging. Relatively simple processors and memory structures could perform subtraction methods with some degree of success. However, even in that early stage, it was clear to many of those involved in the technical developments and in early clinical evaluations that subtraction was only one of many features that would motivate the change from traditional film technique…
Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images
2014
Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …
Graph-matching based CTA.
2009
Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to subst…
Vertebrobasilar junction giant aneurysm: Lessons learned from a neurosurgical audit and anatomical investigation.
2015
The treatment of vascular lesions of the vertebrobasilar junction (VBJ) remains a challenging task in the neurosurgical practice and the gold standard therapy is still under debate. In this article, the authors report a detailed postmortem study of a VBJ giant aneurysm (GA) previously endovascularly treated. Although the decision-making process for the vast majority of neurosurgical treatment can nowadays be accurately carried out during the preoperative planning (i.e., with the aid of neuroimaging fusion protocols, neuronavigation platforms, etc.) meant to maximize the anatomical understanding of the lesions and minimize possible intraprocedural challenges, this postmortem study represents…
Management of aneurysmal subarachnoid hemorrhage: State of the art and future perspectives
2017
Background: Aneurysmal subarachnoid hemorrhage (SAH) accounts for 5% of strokes and carries a poor prognosis. It affects around 6 cases per 100,000 patient years occurring at a relatively young age. Methods: Common risk factors are the same as for stroke, and only in a minority of the cases, genetic factors can be found. The overall mortality ranges from 32% to 67%, with 10–20% of patients with long-term dependence due to brain damage. An explosive headache is the most common reported symptom, although a wide spectrum of clinical disturbances can be the presenting symptoms. Brain computed tomography (CT) allow the diagnosis of SAH. The subsequent CT angiography (CTA) or digital subtraction …
Die Rolle der Farbduplexsonographie bei Diagnose und Differentialdiagnose von Glomus-caroticum-Tumoren*
1996
BACKGROUND Currently the diagnosis of tumorous lesions of the carotid bifurcation is the domain of magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). So far, colour Doppler imaging (CDI) has not been playing an important part in this field. The aim of this study was to define the diagnostic value of CDI in the evaluation of these tumours related to the big arteries and to compare the different imaging techniques. PATIENTS AND METHODS 6 female patients with suspected tumours of the carotid bifurcation were examined with CDI. Additionally 5 MRI examinations and 3 preoperative diagnostic DSA examinations were performed in the same patients. Pathologically, there were 4…
Computerized estimation of quality standards for the X-ray densitometric assessment of myocardial perfusion
2003
The densitometric evaluation of heart-phase-gated digital subtraction coronary angiograms derives different parameters which provide information about coronary blood flow, myocardial perfusion, and coronary flow reserve: appearance time, rise time, mean ascending time, and maximum intensity. The reliability and reproducibility of these measurements and of the derived parameters were investigated. Four digital subtraction coronary angiograms were obtained in ten patients, including two baseline measurements and two measurements under hyperemia induced by papaverine ic. Different reproducibility results were found for the parameters, depending on the heart phase of the densogram (diastolic be…