Multi-domain learning CNN model for microscopy image classification

For any type of microscopy image, getting a deep learning model to work well requires considerable effort to select a suitable architecture and time to train it. As there is a wide range of microscopes and experimental setups, designing a single model that can apply to multiple imaging domains, instead of having multiple per-domain models, becomes more essential. This task is challenging and somehow overlooked in the literature. In this paper, we present a multi-domain learning architecture for the classification of microscopy images that differ significantly in types and contents. Unlike previous methods that are computationally intensive, we have developed a compact model, called Mobincep, by combining the simple but effective techniques of depth-wise separable convolution and the inception module. We also introduce a new optimization technique to regulate the latent feature space during training to improve the network's performance. We evaluated our model on three different public datasets and compared its performance in single-domain and multiple-domain learning modes. The proposed classifier surpasses state-of-the-art results and is robust for limited labeled data. Moreover, it helps to eliminate the burden of designing a new network when switching to new experiments

Formation and Dissociation of Hydrate Plugs in a Water in Oil Emulsion

4 pagesIn this paper, we present experimental results of the formation and dissociation of methane hydrate plugs in a semi-batch reactor. The plugs are done from water in heptane emulsion (water content from 30 %). The experimental results shows that the formation rate and dissociation rate are controlled by the heat transfer at the wall of the reactor. An unexpected behaviour is observed as the temperature decreases under the 0°C temperature during dissociation and seems to form ice which slows down the dissociation rate

Closed combination of context-embedding iterative strategies

This work is motivated by the challenging problem of the computer-aided generation of approximations (viewed as a series of transformations) of partial derivative equations. In this framework, the approximations posed over complex settings are incrementally constructed by extending an approximation posed on a simple setting and combining these extensions. In order to formalize these extensions and their combination, we introduce a class of rewriting strategies, called context-embedding iterative strategies (CE-strategies, for short). Roughly speaking, the class of CE-strategies is constructed by means of adding contexts and an iteration operator allowing the definition of recursive strategies. We show that the class of CE-strategies is closed under combination with respect to a correctness-completeness criterion. It turns out that the class CE-strategies enjoy nice algebraic properties, namely, the combination is associative, has a neutral element, and all the elements are idempotents

Instabilité et turbulence dans des écoulements bidimensionnels MHD

We create two-dimensional flows within a thin horizontal mercury layer subjected to a vertical uniform magnetic field. The fluid is set in motion by injecting electrical currents.The first considered flow is a couple of vortices which signs is alternated. We study through visualizations. They reveal the spatial distribution of the velocity field. We calculate the vorticity and stream function by numerical processing of digitized velocity field. These two variables allow us to characterize the encountered stationary vortex structures.Then we turn to a hexagonal network of forced vortex, and we follow the destabilization of this periodic network. We show that even well beyond the transition, destabilized flow is governed by the interaction of nonlinear waves that appeared at times of transition.When disrupting the previous flow on a large scale before the spatial period of the network, a disorganized motion appears. We show that the fluctuating velocity component is quasi homogeneous and isotropic. Velocity fluctuations play an active role in transfers of inertial energy. We check that these transfers are described by the phenomenological laws of two-dimensional turbulence.Nous créons des écoulements bidimensionnels à l’intérieur d’une couche de mercure mince, horizontale et soumise à un champ magnétique uniforme vertical. Le fluide est mis en mouvement en injectant des courants électriques.Le premier type d’écoulements considéré est un couple de tourbillons de signes alternés. Nous l’étudions au moyen de visualisations. Elles révèlent la répartition spatiale du champ de vitesse. Nous calculons la vorticité et la fonction de courant par un traitement numérique du champ de vitesse digitalisé. Ces deux grandeurs nous permettent de caractériser les structures tourbillonnaires stationnaires rencontrées.Nous nous intéressons ensuite à un réseau hexagonal de tourbillons forcé, et suivons la déstabilisation de ce réseau périodique. Nous montrons que même bien au-delà de la transition, l’écoulement déstabilisé est gouverné par les interactions d’ondes non linéaires qui sont apparues aux moments de la transition. Lorsqu’on perturbe l’écoulement précédent à une échelle grande devant la période spatiale du réseau, un mouvement plus désorganisé apparaît. Nous montrons que la composante fluctuante de la vitesse est quasi homogène isotrope. Les fluctuations de la vitesse jouent le rôle actif dans les transferts inertiaux d’énergie. On vérifie que ces transferts sont décrits par les lois phénoménologiques de la turbulence bidimensionnelle

On the crystallization behavior of syndiotactic-b-atactic polystyrene stereodiblock copolymers, atactic/syndiotactic polystyrene blends, and aPS/sPS blends modified with sPS-b-aPS

International audienceCrystallization and morphological features of syndiotactic-b-atactic polystyrene stereodiblock copolymers (sPS-b-aPS), atactic/syndiotactic polystyrene blends (aPS/sPS), and aPS/sPS blends modified with sPS-b-aPS, with different compositions in aPS and sPS, have been investigated using differential scanning calorimetry (DSC), polarized light optical microscopy (POM) and wide angle X-ray diffraction (WAXRD) techniques. For comparative purposes, the properties of parent pristine sPS samples were also studied. WAXRD analyses revealed for all the samples, independently from their composition (aPS/sPS ratio) and structure (blends, block copolymers, blends modified with block copolymers), the same polymorphic β form of sPS. The molecular weight of aPS and sPS showed opposite effects on the crystallization of 50:50 aPS/sPS blends: the lower the molecular weight of aPS, the slower the crystallization while the lower the molecular weight of sPS, the faster the crystallization. DSC studies performed under both isothermal and non-isothermal conditions, independently confirmed by POM studies, led to a clear trend for the crystallization rate at a given sPS/aPS ratio (ca. 50:50 and 20:80): sPS homopolymers > sPS-b-aPS block copolymers ∼sPS/aPS blends modified with sPS-b-aPS copolymers > sPS/aPS blends. Interestingly, sPS-b-aPS block copolymers not only crystallized faster than blends, but also affected positively the crystallization behavior of blends. At 50:50 sPS/aPS ratio, blends (Blend-2), block copolymers (Cop-1) and blends modified with block copolymers (Blend-2-mod) crystallized via spherulitic crystalline growth controlled by an interfacial process. In all cases, an instantaneous nucleation was observed. The density of nuclei in block copolymers (160,000−190,000 nuclei mm−3) was always higher than that in blends and modified blends (30,000−60,000 nuclei mm−3), even for quite different sPS/aPS ratio. At 20:80 sPS/aPS ratio, the block copolymers (Cop-2) preserved the same crystallization mechanism than at 45:55 ratio (Cop-1). On the other hand, the 20:80 sPS/aPS blend (Blend-4) and blend modified with block copolymers (Blend-4-mod) showed a spinodal decomposition

E box motifs as mediators of proviral latency of human retroviruses

The palindromic sequence motifs (CANNTG) known as E boxes are considered as binding sites for the basic helix-loop-helix (bHLH) class of DNA-binding proteins. Their presence has been reported in the long terminal repeats (LTR) of the HIV-1 and HTLV-1 proviruses. Their close proximity with the TATA region of both LTRs indicates that the bHLH proteins may act as important regulators of the function of proviral transcription. Indeed, observations on HIV-1 and recent results on HTLV-1 underline that these E boxes may be critically involved in the regulation of the proviral transcription of these human retroviruses. Indeed, of the two E boxes flanking the TATA sequences of the HIV-1 provirus, the 3' E box has been implicated in the transcriptional inhibition of viral gene expression. Such a role might also be played by the unique 5' E box present in the HTLV-1 LTR. In both cases, the expression of tissue-specfic bHLH proteins, like TAL1 might counteract the inhibitory effect exerted by E box proteins, thereby increasing proviral transcription. Finally, a phylogenetic study encompassing several subtypes of these two human retroviruses underlines that these E box motifs have recently appeared in the proviral LTRs and may be considered as potential mediators in the establishment of proviral latency

Acidification des eaux de source et saturnisme dans le Massif vosgien.

Les recherches menées à  l'occasion du programme DEFORPA ont montré que les dépôts acides et la sylviculture avaient directement contribué à une acidification des sols et des eaux de surface du Massif vosgien. L'étude de la variation de l'acidité des eaux de source depuis 30 ans a confirmé une acidification progressive de l'eau captée sur les roches les plus pauvres, comme le grès vosgien. Nous avons expérimentalement vérifié que cette acidification a considérablement augmenté la teneur en plomb de l'eau chez les résidents dont les canalisations d'eau potable sont en plomb. Le nombre élevé de cas de saturnisme hydrique observés par les médecins au cours des années 1980 dans le Massif vosgien est attribué directement à  cette acidification des eaux, et indirectement et pour partie à la pollution acide atmosphérique