Denoising Adversarial Autoencoders: Classifying Skin Lesions Using Limited Labelled Training Data

We propose a novel deep learning model for classifying medical images in the setting where there is a large amount of unlabelled medical data available, but labelled data is in limited supply. We consider the specific case of classifying skin lesions as either malignant or benign. In this setting, the proposed approach -- the semi-supervised, denoising adversarial autoencoder -- is able to utilise vast amounts of unlabelled data to learn a representation for skin lesions, and small amounts of labelled data to assign class labels based on the learned representation. We analyse the contributions of both the adversarial and denoising components of the model and find that the combination yields superior classification performance in the setting of limited labelled training data.Comment: Under consideration for the IET Computer Vision Journal special issue on "Computer Vision in Cancer Data Analysis

The effect of word prediction settings (frequency of use) on text input speed in persons with cervical spinal cord injury: a prospective study

International audiencePurpose: To determine whether activation of the frequency of use and automatic learning parameters ofword prediction software has an impact on text input speed.Methods: Forty-five participants with cervical spinal cord injury between C4 and C8 Asia A or B acceptedto participate to this study. Participants were separated in two groups: a high lesion group for participantswith lesion level is at or above C5 Asia AIS A or B and a low lesion group for participants with lesion isbetween C6 and C8 Asia AIS A or B. A single evaluation session was carried out for each participant. Textinput speed was evaluated during three copying tasks:- without word prediction software (WITHOUT condition)- with automatic learning of words and frequency of use deactivated (NOT_ACTIV condition)- with automatic learning of words and frequency of use activated (ACTIV condition)Results: Text input speed was significantly higher in the WITHOUT than the NOT_ACTIV (p<0.001) orACTIV conditions (p¼0.02) for participants with low lesions. Text input speed was significantly higher inthe ACTIV than in the NOT_ACTIV (p¼0.002) or WITHOUT (p<0.001) conditions for participants with highlesions.Conclusions: Use of word prediction software with the activation of frequency of use and automatic learningincreased text input speed in participants with high-level tetraplegia. For participants with low-leveltetraplegia, the use of word prediction software with frequency of use and automatic learning activatedonly decreased the number of errors

Influence of the Number of Predicted Words on Text Input Speed in Participants With Cervical Spinal Cord Injury: Influence of the number of predicted words in persons with SCI

International audienceObjective - To determine if the number of words displayed in the Word Prediction Software (WPS) list affects Text Input Speed (TIS) in people with cervical Spinal Cord Injury (SCI) and if any influence is dependent on the level of the lesion.Design - A cross-sectional trial.Setting - A rehabilitation center in France.Participants - Ninety persons with cervical SCI fulfilled the inclusion/exclusion criteria, 45 of whom agreed to participate. Lesion level was high (C4 and C5 Asia A or B) for 15 participants (high lesion group) and was between C6 and C8 Asia A or B for 30 participants (low lesion group).Methods - TIS was evaluated during 4. 10-minute copying tasks: -without WPS (Without)-with a display of 3 predicted words (3Words)-with a display of 6 predicted words (6Words)-with a display of 8 predicted (8Words)Outcome Measures -During the 4 copying tasks, TIS was measured objectively (characters per minute, number of errors) and subjectively through subject report (fatigue, perception of speed, cognitive load, satisfaction)Results -For participants with low cervical SCI, text input speed without WPS was faster than with WPS, regardless of the number of words displayed (p<0.001). For participants with high cervical SCI, the use of WPS did not influence TIS (p=0.99). There was no influence of the number of words displayed in a word prediction list on TIS, however perception of TIS differed according to lesion level.Conclusion - For persons with low cervical SCI, a small number of words should be displayed, or WPS should not be used at all. For persons with high cervical SCI, a larger number of words displayed increases the comfort of use of WP

Effect of a Dynamic Keyboard and Word Prediction Systems on Text Input Speed in Patients with Functional Tetraplegia

International audienceInformation technology plays a very important role in society. People with disabilities are often limited by slow text input speed despite the use of assistive devices. This study aimed to evaluate the effect of a dynamic on-screen keyboard (Custom Virtual Keyboard) and a word-prediction system (Sibylle) on text input speed in participants with functional tetraplegia. Ten participants tested four modes at home (static on-screen keyboard with and without word prediction and dynamic on-screen keyboard with and without word prediction) for 1 mo before choosing one mode and then using it for another month. Initial mean text input speed was around 23 words per minute with the static keyboard and 12 words per minute with the dynamic keyboard. The results showed that the dynamic keyboard reduced text input speed by 37% compared with the standard keyboard and that the addition of word prediction had no effect on text input speed. We suggest that current forms of dynamic keyboards and word prediction may not be suitable for increasing text input speed, particularly for subjects who use pointing devices. Future studies should evaluate the optimal ergonomic design of dynamic keyboards and the number and position of words that should be predicted

Écoulements liquide-liquide dispersés homogènes en conduite horizontale : approche locale en milieu concentré

Dans ce travail, des écoulements liquide-liquide dispersés homogènes (c'est-à-dire sans gradient de concentration) ont été étudiés dans une conduite horizontale de 7.5m de long et de 50mm de diamètre interne. Les expériences ont été réalisées dans une large gamme de paramètres opératoires (vitesses de mélange comprises entre 0.28 et 1.2m/s et concentration volumique en phase dispersée, φ, de 0.08 à 0.7). Le facteur de frottement de ces écoulements a été mesuré et modélisé en régime turbulent, intermédiaire et laminaire. Ces différents régimes ainsi que l’effet de la concentration en phase dispersée ont été identifiés à partir des mesures locales de vitesse par une technique de vélocimétrie par image de particules (PIV). Lorsque φ≤0.56, les dispersions se comportent comme des fluides newtoniens auxquels le concept de viscosité effective peut s’appliquer. Le modèle de viscosité de Krieger et Dougherty (1959) décrit l’ensemble des émulsions formées. Le facteur de frottement mesuré suit les lois de frottement classiques en régime laminaire et turbulent (Hagen-Poiseuille et Blasius respectivement) en fonction du nombre de Reynolds basé sur les propriétés de mélange des émulsions (densité et viscosité). Toutefois, la concentration en phase dispersée induit un retard à l’apparition de la turbulence. En milieu très concentré (φ=0.7), la dispersion a un comportement rhéofluidifiant et suit la loi d’Ostwald avec un exposant, n=0.5. Tous ces écoulements ont été étudiés, en détail, par l’analyse locale des vitesses. ABSTRACT : Homogeneous dispersed flows have been investigated in a horizontal pipe (7.5m long and 50mm internal diameter) in a wide range of flow parameters (mixture velocity from 0.28 to 1.2m/s and concentration, φ, up to 0.7). In this work, the wall friction of this emulsion has been measured and modeled in turbulent, intermediate and laminar regime. The different flow regime and the effect of dispersed phase volume fraction have been determined from the velocity profiles measured by PIV measurements in a refractive index matched medium. When φ≤0.56, emulsion behaves as newtonian fluid. It was shown that the concept of effective viscosity is relevant to scale the wall friction of the emulsion flow. The effective viscosity follows the classical trend of low inertia suspension of hard spheres (Krieger and Dougherty 1959). The friction factor is described by the classical single phase laws in turbulent and laminar regime (Hagen-Poiseuille and Blasius respectively) as a function of Reynolds number based on mixture properties (density and viscosity). Compared to single phase flow, the transition to turbulence is delayed as dispersed phase fraction is increased. For higher dispersed phase fraction (φ=0.7), emulsion behaves as a shear-thinning fluid. Emulsion follows the Ostwald law with an exponent equal to 0.5. All these homogeneous dispersed flow have been studied in details

Total synthesis and absolute configuration assignment of MRSA active garcinol and isogarcinol

A short total synthesis of (±)-garcinol and (±)-isogarcinol, two endo-type B PPAPs with reported activity against methiciline resistant Staphylococcus aureus (MRSA), is presented. The separation of framework-constructing from framework-decorating steps and the application of two highly regio- and stereoselective Pd-catalysed allylations, that is, the Pd-catalysed decarboxylative Tsuji-Trost allylation and the diastereoselective Pd-catalysed allyl-allyl cross-coupling, are key elements that allowed the total synthesis to be accomplished within 13 steps starting from acetylacetone. After separation of the enantiomers the absolute configurations of the four natural products (i.e., (-)-garcinol, (+)-guttiferone E (i.e., ent-garcinol), (-)-isogarcinol, and (+)-isoxanthochymol (i.e., ent-isogarcinol)) were assigned based on ECD spectroscopy.Fil: Socolsky, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Plietker, Bernd . Universität Stuttgart. Institut für Organische Chemie; Alemani

Dextran fractional clearance studies in acute dengue infection

Background Although increased capillary permeability is the major clinical feature associated with severe dengue infections the mechanisms underlying this phenomenon remain unclear. Dextran clearance methodology has been used to investigate the molecular sieving properties of the microvasculature in clinical situations associated with altered permeability, including during pregnancy and in various renal disorders. In order to better understand the characteristics of the vascular leak associated with dengue we undertook formal dextran clearance studies in Vietnamese dengue patients and healthy volunteers. Methodology/Principal Findings We carried out serial clearance studies in 15 young adult males with acute dengue and evidence of vascular leakage a) during the phase of maximal leakage and b) one and three months later, as well as in 16 healthy control subjects. Interestingly we found no difference in the clearance profiles of neutral dextran solutions among the dengue patients at any time-point or in comparison to the healthy volunteers. Conclusions/Significance The surface glycocalyx layer, a fibre-matrix of proteoglycans, glycosaminoglycans, and plasma proteins, forms a complex with the underlying endothelial cells to regulate plasma volume within circumscribed limits. It is likely that during dengue infections loss of plasma proteins from this layer alters the permeability characteristics of the complex; physical and/or electrostatic interactions between the dextran molecules and the glycocalyx structure may temporarily restore normal function, rendering the technique unsuitable for assessing permeability in these patients. The implications for resuscitation of patients with dengue shock syndrome (DSS) are potentially important. It is possible that continuous low-dose infusions of dextran may help to stabilize the permeability barrier in patients with profound or refractory shock, reducing the need for repeated boluses, limiting the total colloid volume required. Formal clinical studies should help to assess this strategy as an alternative to conventional fluid resuscitation for severe DSS

Evaluation de l’efficacité des logiciels de prédiction de mots sur la vitesse de saisie de texte sur l’outil informatique pour les personnes blessées médullaires cervicaux

The main objective of this work was to study the influence of key settings of word predictionsoftware as well as a training program on the use of word prediction, on text input speed in personswith cervical spinal cord injury.Study 1 determined text input speed in persons with cervical spinal cord injury and the influence ofpersonal characteristics and type of computer device on text input speed. Study 2 evaluated theeffect of a dynamic virtual keyboard coupled with word prediction software on text input speed inpersons with functional tetraplegia. Study 3 analysed the word prediction software settingscommonly prescribed by health-related professionals for people with cervical spinal cord injury.Studies 4 and 5 evaluated the influence of the number of words displayed in the prediction list andthe frequency of use setting on text input speed. Finally, study 6 evaluated the influence of a trainingprogram on the use of word prediction software for persons with cervical spinal cord injury on textinput speed.The results showed that only the type of computer device influenced text input speed; voicerecognition software increased the text input speed of persons with cervical spinal cord injury to thatof able-bodied people using a standard keyboard. The influence of the different word predictionsoftware settings (number of words displayed in the prediction list and the frequency of use) on textinput speed, the number of errors or comfort of use, differed depending on the level of injury. Wealso found differences between the perception of the importance of some settings by healthprofessionalsand data in the literature regarding the optimization of settings. Moreover, althoughsome parameters were considered as very important, they were rarely configured. Finally, trainingpersons with cervical spinal cord injury in the use of word prediction software increased text inputspeed.The results of this work highlighted that word prediction software settings influence text input speedin persons with cervical spinal cord injury, however not all professionals are aware of this.Information should therefore be disseminated through professional networks. Further studies shouldaim to improve word prediction software and should also focus on new devices such as tablets andvoice recognition software. Persons with cervical spinal cord injury training programs in the use ofword prediction software need to be developed and validated.Ce travail de thèse avait pour objectif principal d’étudier l’influence de certains paramétrages deslogiciels de prédiction de mots et d’un programme d’entraînement ciblé sur la vitesse de saisie detexte chez des personnes tétraplégiques. Six études ont été menées. L’étude 1 nous a permis demettre en évidence des vitesses de saisie de texte chez les personnes tétraplégiques et d’étudierl’influence de leurs aides techniques d’accès à l’outil informatique sur cette vitesse. L’étude 2 nous apermis de mettre en avant l’hétérogénéité des résultats d’un logiciel de prédiction de mots sur lavitesse de saisie de texte sur une population hétérogène et sans paramétrage de ces logiciels.L’étude 3 nous a permis d’étudier les habitudes de préconisations et de paramétrages des logiciels deprédictions de mots par les professionnels. Les études 4 et 5 nous ont permis d’évaluer l’influencedes paramétrages (nombre de mots affichés dans la liste de prédiction et l’adaptation du logiciel auvocabulaire de l’utilisateur) sur cette saisie de texte. Enfin, l’étude 6 nous a permis d’étudierl’influence d’un entraînement dirigé par des professionnels sur les logiciels de prédictions de motschez des personnes tétraplégiques, sur la vitesse de saisie de texte.Les résultats montrent que seule l’aide technique d’accès à l’outil informatique influence la vitessede saisie de texte. Les logiciels de reconnaissance vocale permettent une vitesse de saisie de texteéquivalente à celle des personnes valides utilisant un clavier standard. Les paramétrages (nombre demots affichés dans la liste de prédiction et l’adaptation du logiciel au vocabulaire de l’utilisateur) ontune influence différente en fonction du niveau lésionnel des personnes tétraplégiques sur la vitessede saisie de texte, le nombre d’erreurs ou le confort. De plus, une différence entre l’importancedonnée aux paramétrages par les professionnels préconisateurs et les paramétrages effectivementréglés a été mise en évidence. Enfin, l’influence d’un entraînement dirigé sur la vitesse de saisie detexte a été mise en évidence sur la vitesse de saisie de texte. Au regard de l’ensemble de cesrésultats, il apparait nécessaire de paramétrer les logiciels de prédictions de mots, mais aussi deconnaitre l’influence des différents réglages et de diffuser cette information au sein des réseauxprofessionnels. La recherche doit être poursuivie pour améliorer les logiciels de prédiction de mots,mais aussi pour favoriser de nouveaux outils tels les tablettes tactiles et les logiciels dereconnaissance vocale. Une systématisation des entraînements dirigés sur les logiciels de prédictionde mots nécessite une réflexion et une validation sur les modalités et la nature de cesaccompagnements