Comparison of classification methods : An application in underwater ferromagnetic object identification

The time-frequency analysis of magnetic signals, generated by ferromagnetic objects, is used to extract a robust discriminan t parameter set for their classification . After the feature selection phase, an extensive study is performed in order to validate th e most appropriate classifier structure, in terms of the correct classification rate and the generalization ability . The K-NN Famil y and the neural networks based classifiers are the candidates we are working with . The Fuzzy-logic contribution and the neura l networks capabilities are highlighted by means of a large number of test vectors and for a significative S/N ratio range.L'analyse temps-fréquence des signaux magnétiques, générés par des objets ferromagnétiques sous-marins, est utilisée afin de trouver un ensemble de paramètres discriminants pour leur classification. Après l'étape de sélection de caractéristiques, une étude étendue est menée pour comparer différentes structures de classifieurs, en fonction du taux moyen de bonne classification et de la capacité de généralisation. Les vertus de la logique floue, intégrée dans les classifieurs de la famille des K plus proches voisins (K-NN), et des classifieurs à base de réseaux de neurones sont mises en évidence au moyen d'un grand nombre de vecteurs de test et à une plage significative de variation pour le rapport S/B

Modélisation des cibles détectées par un radar de surveillance maritime à haute résolution

- Afin d'optimiser les performances des radars à haute résolution pour la détection à la surface de la mer il est nécessaire de développer des modèles adéquats aussi bien pour les cibles navales que pour le fouillis de mer. Alors que ce dernier fait l'objet de nombreuses études, les modèles des cibles utilisés sont toujours ceux développés par Swerling. Le modèle proposé dans l'article intègre les effets de la haute résolution en distance assurée par le radar et de la visibilité géométrique discontinue, qui apparaît surtout dans le cas des petites cibles

Application d'opérateurs de fusion floue à la classification automatique de cibles réalisée par un radar polarimétrique

L'article décrit l'application de quelques opérateurs de fusion floue pour la classification automatique de profils de distance mesurés par un radar polarimétrique. L'acquisition des signatures radar réelles est réalisée dans la chambre anéchoïde de l'ENSIETA, pour 5 modèles d'avions réduits à l'échelle et 3 combinaisons de polarisation. L'analyse des résultats en classification obtenus au travers des intégrales de Sugeno et de Choquet, ainsi que de la théorie des possibilités, permet de conclure sur les opérateurs de fusion floue les mieux adaptés dans le contexte de l'application visée

Technique neuronale pour la détection CFAC optimale dans du fouillis de mer non-Gaussien

- Un nouveau processeur radar CFAR (Constant False Alarm Rate) pour la détection optimale des cibles navales est proposé dans l'article. Il est basé sur l'utilisation d'un réseau de neurones pour approximer de façon implicite, par apprentissage, les densités de probabilité multidimensionnelles correspondant au fouillis et au signal écho utile. La règle de décision utilisée est équivalente au test du maximum du rapport de vraisemblance généralisé. Des méthodes pour le calcul du seuil de détection et pour assurer son invariance par rapport au rapport S/B et aux paramètres du fouillis sont également présentées

The Sport Concussion Assessment Tool (SCAT2) for evaluating civilian mild traumatic brain injury

Post-concussion symptoms; SCAT2; Head injurySíntomas posteriores a la conmoción cerebral; SCAT2; Lesión cranealSímptomes posteriors a la commoció cerebral; SCAT2; Lesió cranialSelf-report measures, particularly symptom inventories, are critical tools for identifying patients with persistent post-concussion symptoms and their follow-up. Unlike in military or sports-related assessment, in general civilian settings pre-injury levels of concussion-like symptoms are lacking. Normative data are available in adolescent and college populations, but no reference data exist to guide clinical adult explorations. The purpose of this study was to use the second edition of the Sport Concussion Assessment Tool (SCAT2) to profile a cohort of 60 healthy community volunteers who had not sustained a head injury. Participating volunteers underwent MRI scanning and were evaluated with the Hospital Anxiety and Depression Scale (HADS). Participants reported a median of 3 concussion-like symptoms and the 97.5 percentile score was found at 10.5 symptoms, out of a total of 22. The median severity score was 4.9 points, and 28.9 was the upper limit of the reference interval. Only 10 participants (16.7%) did not endorse any symptom. The most frequently endorsed symptom was feeling difficulty in concentrating, with 41.7% of the sample reporting it. Age, sex and general distress, anxiety and depressive symptoms were not associated with concussion-like symptoms. Our data yielded elevated cut-offs scores for both the number of symptoms and the symptom severity. In conclusion, postconcussive-like symptoms are frequent in the general non-concussed adult population and it should be taken into account in any future models developed for screening patients at risk of developing physical, cognitive, and psychological complaints following mild traumatic injury.UNINN is supported by a Grant from the Generalitat de Catalunya (SGR 2014-844, http://agaur.gencat.cat). This work has been supported in part by the Fondo de Investigacion Sanitaria (Instituto de Salud Carlos III, https://portalfis.isciii.es) with grants FIS PI11/00700 (J.S.) and grant FIS PI13/02397 (M.A.P.), which were co-financed by the European Regional Development Fund (ERDF). A.R. was a recipient of a pre-doctoral grant from the Fundacio Institut de Recerca VHIR (PRED-VHIR-2012-26, http://en.vhir.org)

Radiofrequency ablation in primary colo-rectal cancer and liver metastasis

Institutul Oncologic Bucuresti, Clinica de Chirurgie Nr. 1, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Ablaţia prin radiofrecvenţă constituie o soluţie terapeutică recentă în chirurgia determinărilor primare sau secundare din neoplasmele colorectale. Realizată prin abord deschis, laparo-endoscopic sau percutan, metoda asigură un control acceptabil asupra procesului tumoral, cu riscuri reduse comparativ cu chirurgia de exereză, cu condiţia respectării stricte a indicaţiilor. Obiective. Evaluăm această procedură terapeutică, aplicată pentru indicaţia clasică din metastazele hepatice, cât şi pentru tumorile rectale joase sau recidive pelvine după cancer rectal operat, prin prisma experienţei acumulate pe parcursul a 4 ani, focusând complicaţiile perioperatorii şi rata de recidivă locală şi evoluţia la distanţă. Metoda. În perioada decembrie 2006 – martie 2010 au fost trataţi prin radiofrecvenţă 64 pacienţi, 46 cu metastaze hepatice secundare CRC, iar 18 cu cancer rectal inferior sau recidive pelvine; procedura s-a realizat în majoritatea cazurilor sub control echografic intraoperator, prin abord chirurgical clasic în 59 cazuri, iar în 5 cazuri prin abord laparoscopic. Evoluţia pacienţilor a fost monitorizată imagistic prin CT postoperator la 30 zile, ulterior din 3 în 3 luni, urmărirea markerilor tumorali (CEA, CA19.9.) şi control endoscopic. Rezultate. Complicaţii perioperatorii s-au inregistrat la 6 pacienţi si au constat în sindroame febrile, citolize hepatice. Nu s-au înregistrat complicaţii de tipul hemoragiilor, fistulelor sau peritonitelor; şi nici mortalitate perioperatorie imputabilă metodei. Recidive locale înregistrate, la un interval de 6-25 luni, la 12 pacienți. Concluzii. Experienţa iniţială arată că radioablaţia în chirurgia determinărilor primare sau secundare din neoplasmele colo-rectale este o procedură relativ sigură, grefată de morbiditate redusă şi rata scazută de recidivă locală; urmează ca studii de urmărire pe perioade mai întinse să confirme valoarea metodei.Radiofrequency ablation represent a therapeutic option for primary colo-rectal cancer and liver metastasis, performed by open surgery, laparoscopic approach or percutaneous, provide a reasonable local tumor control, involved low risks comparative resection surgery. Objectives. We analyzed this procedure, for classic indication in hepatic metastatic tumors, as well as in low rectal tumors and pelvic recurrences after rectal surgery based on four years experience, focused on perioperative complications, recurrence rate and long distant evolution. Method. Between December 2006 and March 2010, 64 patients underwent RFA; 46 cases had metastatic lesions from colo-rectal cancer and 18 cases had low rectal cancer or pelvic recuurrence. RFA was performed in 59 patients via open surgery and laparoscopic approach in 5 patients. Postoperative course was followed with CT scan at 1 month, and then at 3 month interval, in correlation with tumor markers level (CEA, CA19.9.) and endoscopic control. Results. Perioperative complications occurred in 6 cases, consist of prolonged fever, severe hepatic cytolysis, without other complications such, biliary tract injury, hemorrhage, and peritonitis; no mortality caused by RFA procedure. 12 cases had local recurrence, at 6 and 25 month after post RFA procedure. Concluzii. Initial experience shows that RFA is a safe procedure for treatment of primary colo-rectal cancer and liver metastasis, with low rate of morbidity and local recurrence, indicated for patients with unresecable lesions or high risks for surgical resection

Prevalence and Outcomes for Heavily Treatment-Experienced (HTE) Individuals Living with Human Immunodeficiency Virus in a European Cohort

BACKGROUND: Although antiretroviral treatments have improved survival of persons living with HIV, their long-term use may limit available drug options. We estimated the prevalence of heavily treatment-experienced (HTE) status and the potential clinical consequences of becoming HTE. SETTING: EuroSIDA, a European multicentre prospective cohort study. METHODS: A composite definition for HTE was developed, based on estimates of antiretroviral resistance and prior exposure to specific antiretroviral regimens. Risks of progressing to clinical outcomes were assessed by Poisson regression, comparing every HTE individual with three randomly-selected controls who never became HTE. RESULTS: Of 15,570 individuals under follow-up in 2010-2016, 1617 (10.4%, 95% CI 9.9-10.9%) were classified as HTE. 1093 individuals became HTE during prospective follow-up (HTE incidence rate 1.76, CI 1.66-1.87 per 100 person-years of follow-up). The number of HTE individuals was highest in West/Central Europe (636/4019 persons, 15.7%) and lowest in East Europe (26/2279 persons, 1.1%). Although most HTE individuals maintained controlled viral loads (<400 copies/ml), many had low CD4 counts (≤350 cells/µl). After controlling for age, immunological parameters and pre-existing comorbidities, HTE status was not associated with the risk of new AIDS (adjusted incidence rate ratio, aIRR 1.44, CI 0.86-2.40, p = 0.16) or non-AIDS clinical events (aIRR 0.96, CI 0.74-1.25, p = 0.77). CONCLUSIONS: HTE prevalence increased with time. After adjusting for key confounding factors, there was no evidence for an increased risk of new AIDS or non-AIDS clinical events in HTE. Additional therapeutic options and effective management of comorbidities remain important to reduce clinical complications in HTE individuals

Compensatory-reserve-weighted intracranial pressure versus intracranial pressure for outcome association in adult traumatic brain injury: a CENTER-TBI validation study

Background: Compensatory-reserve-weighted intracranial pressure (wICP) has recently been suggested as a supplementary measure of intracranial pressure (ICP) in adult traumatic brain injury (TBI), with a single-center study suggesting an association with mortality at 6 months. No multi-center studies exist to validate this relationship. The goal was to compare wICP to ICP for association with outcome in a multi-center TBI cohort. Methods: Using the Collaborative European Neuro Trauma Effectiveness Research in TBI (CENTER-TBI) high-resolution intensive care unit (ICU) cohort, we derived ICP and wICP (calculated as wICP = (1 12 RAP) 7 ICP; where RAP is the compensatory reserve index derived from the moving correlation between pulse amplitude of ICP and ICP). Various univariate logistic regression models were created comparing ICP and wICP to dichotomized outcome at 6 to 12 months, based on Glasgow Outcome Score\u2014Extended (GOSE) (alive/dead\u2014GOSE 65 2/GOSE = 1; favorable/unfavorable\u2014GOSE 5 to 8/GOSE 1 to 4, respectively). Models were compared using area under the receiver operating curves (AUC) and p values. Results: wICP displayed higher AUC compared to ICP on univariate regression for alive/dead outcome compared to mean ICP (AUC 0.712, 95% CI 0.615\u20130.810, p = 0.0002, and AUC 0.642, 95% CI 0.538\u2013746, p &lt; 0.0001, respectively; no significant difference on Delong\u2019s test), and for favorable/unfavorable outcome (AUC 0.627, 95% CI 0.548\u20130.705, p = 0.015, and AUC 0.495, 95% CI 0.413\u20130.577, p = 0.059; significantly different using Delong\u2019s test p = 0.002), with lower wICP values associated with improved outcomes (p &lt; 0.05 for both). These relationships on univariate analysis held true even when comparing the wICP models with those containing both ICP and RAP integrated area under the curve over time (p &lt; 0.05 for all via Delong\u2019s test). Conclusions: Compensatory-reserve-weighted ICP displays superior outcome association for both alive/dead and favorable/unfavorable dichotomized outcomes in adult TBI, through univariate analysis. Lower wICP is associated with better global outcomes. The results of this study provide multi-center validation of those seen in a previous single-center study

Univariate comparison of performance of different cerebrovascular reactivity indices for outcome association in adult TBI: a CENTER-TBI study

Background: Monitoring cerebrovascular reactivity in adult traumatic brain injury (TBI) has been linked to global patient outcome. Three intra-cranial pressure (ICP)-derived indices have been described. It is unknown which index is superior for outcome association in TBI outside previous single-center evaluations. The goal of this study is to evaluate indices for 6- to 12-month outcome association using uniform data harvested in multiple centers. Methods: Using the prospectively collected data from the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study, the following indices of cerebrovascular reactivity were derived: PRx (correlation between ICP and mean arterial pressure (MAP)), PAx (correlation between pulse amplitude of ICP (AMP) and MAP), and RAC (correlation between AMP and cerebral perfusion pressure (CPP)). Univariate logistic regression models were created to assess the association between vascular reactivity indices with global dichotomized outcome at 6 to 12&nbsp;months, as assessed by Glasgow Outcome Score\u2013Extended (GOSE). Models were compared via area under the receiver operating curve (AUC) and Delong\u2019s test. Results: Two separate patient groups from this cohort were assessed: the total population with available data (n = 204) and only those without decompressive craniectomy (n = 159), with identical results. PRx, PAx, and RAC perform similar in outcome association for both dichotomized outcomes, alive/dead and favorable/unfavorable, with RAC trending towards higher AUC values. There were statistically higher mean values for the index, % time above threshold, and hourly dose above threshold for each of PRx, PAx, and RAC in those patients with poor outcomes. Conclusions: PRx, PAx, and RAC appear similar in their associations with 6- to 12-month outcome in moderate/severe adult TBI, with RAC showing tendency to achieve stronger associations. Further work is required to determine the role for each of these cerebrovascular indices in monitoring of TBI patients