Morphological operators for very low bit rate video coding

This paper deals with the use of some morphological tools for video coding at very low bit rates. Rather than describing a complete coding algorithm, the purpose of this paper is to focus on morphological connected operators and segmentation tools that have proved to be attractive for compression.Peer ReviewedPostprint (published version

The transmutation of dwarf galaxies : stellar populations

Transition-type dwarf (TTD) galaxies share characteristics of early-and late-type dwarfs. Thus, they are suspected to be the thread that connects them. We selected 19 TTD galaxies in the nearby Universe (cz < 2900 km s(-1)) from the Sloan Digital Sky Survey. They span the luminosity range from similar to-14.5 to -19.0 mag in the B band, and are located in different environments. We derive their single stellar population parameters and star formation histories, using the full spectrum fitting technique with two independent population synthesis models. Irrespective of the synthesis models, we find that these dwarfs have a relatively young mean age (around 1-2 Gyr) and low metallicities (similar to-0.7 dex). Moreover, they had approximately constant star formation rates until a few Gyr ago, associated with strong metal enrichment during the first few Gyr of their evolution. We compare these results with the results from Koleva et al., who studied dwarf elliptical (dE) galaxies in the same luminosity range. We find that (1) both samples occupy the same region in the luminosity-metallicity relation, (2) the build-up of the stellar mass in both types of galaxies is very similar, with most of the stars already formed 5 Gyr ago and (3) contrary to the dEs, TTDs are forming stars at present, but after 1 Gyr of passive evolution, their star formation histories would appear identical to that of dEs. As far as the stellar population is concerned, the transformation of TTDs into dEs is definitely possible. A star-forming dwarf galaxy can be stripped of at least a fraction of its gas, and its star formation rate can be reduced to that of the TTDs of the present sample. Continued gas removal may drive a galaxy to the state of a gas-depleted bona fide dE. However, we cannot exclude a scenario where a star-forming galaxy is rapidly transformed into an early type without passing through a noticeable 'transition' phase, as suggested by the relatively small fraction of observed dEs with an interstellar medium. We cannot exclude swinging back and forth between a late-type dwarf and a TTD (in the case of episodic star formation) or an early-type dwarf and a TTD (in the case of gas infall)

Analyse du champ électrostatique d'un nuage d'orage lors d'un fourdroiement en vol d'un Flacon 20

International audienceSince the 70’s, ONERA has been involved in the understanding and characterization of the physical processes occurring during a lightning strike to the aircraft which has led to the development of on board sensors for atmospheric characterization. In the 80’s, a first electric field mill network had been designed to measure the electrostatic field inside thundercloud. The system was installed on a CONVAIR (CV580) and a TRANSALL (C160). A new version of this electric field mill network, called AMPERA (Atmospheric Measurement of Potential and ElectRic field on Aircraft), has been developed since 2010. From September to October 2018, an in-flight campaign was performed over Corsica (France) in the framework of EXAEDRE (EXploiting new Atmospheric Electricity Data for Research and the Environment) project to investigate the electrical activity in thunderstorm. During this campaign, 8 scientific flights were done with a FALCON 20 (F20) of SAFIRE inside or in the vicinity of thunderstorm. During the flight of the 8 of October 2018, the aircraft was struck by lightning at an altitude of 8500m. The electrostatic field time variations show that a vertical electric polarization of the aircraft occurred just before the lightning strike. The inverse method to compute the components of the atmospheric electric field from the data of the electric field network is presented. The atmospheric electric field time evolution is shown. The value of the atmospheric electric field just before the lightning strike is about 90kV/m. This electric field value has been processed to be compared with the ones measured during TRANSALL campaigns. The altitude effect is taken into account by computing the reduced electric field (Electric field divided by air density). The comparison is presented taking into account the size of the aircraft and the electric field direction. To conclude a discussion is done on the electric field threshold for a lightning strike to aircraft.Dans les années 70, l'ONERA a mené des recherches pour caractériser et comprendre les processus physiques intervenant lors d'un foudroiement en vol d'un avion ce qui a conduit au développement de capteurs pour caractériser l'atmosphère. Dans les années 80, une première version de moulin à champ a été conçue pour mesurer les composantes du champ électrostatique à l'intérieur du nuage depuis un avion. Le système a été installé sur une CONVAIR (CV580) et sur un TRANSALL (C160). Une nouvelle version du système, appelé AMPERA (Atmospheric Measurement of Potential and ElectRic field on Aircraft), a été développée depuis 2010. De septembre à octobre 2018, une campagne en vol a été réalisée en Corse (France) dans le cadre du projet ANR EXAEDRE (EXploiting new Atmospheric Electricity Data for Research and the Environment) pour étudier l'activité électrique des orages.Pendant cette campagne, 8 vols scientifiques ont été réalisés par a FALCON 20 (F20) de SAFIRE à l'intérieur ou à proximité d'un nuage orageux. Pendant le vol du 8 octobre, l'avion a été foudroyé à une altitude de 8500 m. La variation temporelle du champ électrostatique montre que l'avion est polarisé verticalement au moment du foudroiement. La méthode inverse pour calculer les composantes du champ électrostatique est présentée. La valeur du champ atmosphérique au moment du foudroiement est de 90 kV/m. Ce champ électrique a été normalisé pour être comparé aux champs électriques mesurés lors des campagnes TRANSALL. L'effet de l'altitude a été prise en compte en calculant le champ électrique réduit (Champ électrique divisé par la densité de l'air). La taille de l'avion et la direction du champ électrique a été pris en compte pour la comparaison. Pour conclure, une discussion sur le seuil du champ électrique pour déclencher un foudroiement sur un avion

Relationship between Sponsorship and Failure Rate of Dental Implants: A Systematic Approach

BACKGROUND: The number of dental implant treatments increases annually. Dental implants are manufactured by competing companies. Systematic reviews and meta-analysis have shown a clear association between pharmaceutical industry funding of clinical trials and pro-industry results. So far, the impact of industry sponsorship on the outcomes and conclusions of dental implant clinical trials has never been explored. The aim of the present study was to examine financial sponsorship of dental implant trials, and to evaluate whether research funding sources may affect the annual failure rate. METHODS AND FINDINGS: A systematic approach was used to identify systematic reviews published between January 1993 and December 2008 that specifically deal with the length of survival of dental implants. Primary articles were extracted from these reviews. The failure rate of the dental implants included in the trials was calculated. Data on publication year, Impact Factor, prosthetic design, periodontal status reporting, number of dental implants included in the trials, methodological quality of the studies, presence of a statistical advisor, and financial sponsorship were extracted by two independent reviewers (kappa = 0.90; CI(95%) [0.77-1.00]). Univariate quasi-Poisson regression models and multivariate analysis were used to identify variables that were significantly associated with failure rates. Five systematic reviews were identified from which 41 analyzable trials were extracted. The mean annual failure rate estimate was 1.09%.(CI(95%) [0.84-1.42]). The funding source was not reported in 63% of the trials (26/41). Sixty-six percent of the trials were considered as having a risk of bias (27/41). Given study age, both industry associated (OR = 0.21; CI(95%) [0.12-0.38]) and unknown funding source trials (OR = 0.33; (CI(95%) [0.21-0.51]) had a lower annual failure rates compared with non-industry associated trials. A conflict of interest statement was disclosed in 2 trials. CONCLUSIONS: When controlling for other factors, the probability of annual failure for industry associated trials is significantly lower compared with non-industry associated trials. This bias may have significant implications on tooth extraction decision making, research on tooth preservation, and governmental health care policies

Cross-study analysis of genomic data defines the ciliate multigenic epiplasmin family: strategies for functional analysis in Paramecium tetraurelia

<p>Abstract</p> <p>Background</p> <p>The sub-membranous skeleton of the ciliate <it>Paramecium</it>, the epiplasm, is composed of hundreds of epiplasmic scales centered on basal bodies, and presents a complex set of proteins, epiplasmins, which belong to a multigenic family. The repeated duplications observed in the <it>P. tetraurelia </it>genome present an interesting model of the organization and evolution of a multigenic family within a single cell.</p> <p>Results</p> <p>To study this multigenic family, we used phylogenetic, structural, and analytical transcriptional approaches. The phylogenetic method defines 5 groups of epiplasmins in the multigenic family. A refined analysis by Hydrophobic Cluster Analysis (HCA) identifies structural characteristics of 51 epiplasmins, defining five separate groups, and three classes. Depending on the sequential arrangement of their structural domains, the epiplasmins are defined as symmetric, asymmetric or atypical. The EST data aid in this classification, in the identification of putative regulating sequences such as TATA or CAAT boxes. When specific RNAi experiments were conducted using sequences from either symmetric or asymmetric classes, phenotypes were drastic. Local effects show either disrupted or ill-shaped epiplasmic scales. In either case, this results in aborted cell division.</p> <p>Using structural features, we show that 4 epiplasmins are also present in another ciliate, <it>Tetrahymena </it><it>thermophila</it>. Their affiliation with the distinctive structural groups of <it>Paramecium </it>epiplasmins demonstrates an interspecific multigenic family.</p> <p>Conclusion</p> <p>The epiplasmin multigenic family illustrates the history of genomic duplication in <it>Paramecium</it>. This study provides a framework which can guide functional analysis of epiplasmins, the major components of the membrane skeleton in ciliates. We show that this set of proteins handles an important developmental information in <it>Paramecium </it>since maintenance of epiplasm organization is crucial for cell morphogenesis.</p

Evolutionary analyses of non-genealogical bonds produced by introgressive descent

All evolutionary biologists are familiar with evolutionary units that evolve by vertical descent in a tree-like fashion in single lineages. However, many other kinds of processes contribute to evolutionary diversity. In vertical descent, the genetic material of a particular evolutionary unit is propagated by replication inside its own lineage. In what we call introgressive descent, the genetic material of a particular evolutionary unit propagates into different host structures and is replicated within these host structures. Thus, introgressive descent generates a variety of evolutionary units and leaves recognizable patterns in resemblance networks. We characterize six kinds of evolutionary units, of which five involve mosaic lineages generated by introgressive descent. To facilitate detection of these units in resemblance networks, we introduce terminology based on two notions, P3s (subgraphs of three nodes: A, B, and C) and mosaic P3s, and suggest an apparatus for systematic detection of introgressive descent. Mosaic P3s correspond to a distinct type of evolutionary bond that is orthogonal to the bonds of kinship and genealogy usually examined by evolutionary biologists. We argue that recognition of these evolutionary bonds stimulates radical rethinking of key questions in evolutionary biology (e.g., the relations among evolutionary players in very early phases of evolutionary history, the origin and emergence of novelties, and the production of new lineages). This line of research will expand the study of biological complexity beyond the usual genealogical bonds, revealing additional sources of biodiversity. It provides an important step to a more realistic pluralist treatment of evolutionary complexity

Pain catastrophizing and worry about health in generalized anxiety disorder

Because the diagnostic criteria of generalized anxiety disorder (GAD) are not tied to specific worry domains (worry is ‘generalized’), research on the content of worry in GAD is lacking. To our knowledge, no study has addressed vulnerability for specific worry topics in GAD. The goal of the current study, a secondary analysis of data from a clinical trial, is to explore the relationship between pain catastrophizing and worry about health in a sample of 60 adults with primary GAD. All data for this study were collected at pretest, prior to randomization to experimental condition in the larger trial. The hypotheses were that (1) pain catastrophizing would be positively related to the severity of GAD, (2) the relationship between pain catastrophizing and the severity of GAD would not be explained by intolerance of uncertainty and psychological rigidity, and (3) pain catastrophizing would be greater in participants reporting worry about health compared to those not reporting worry about health. All hypotheses were confirmed, suggesting that pain catastrophizing may be a threat-specific vulnerability for health-related worry in GAD. The implications of the current findings include a better understanding of the ideographic content of worry, which could help focus treatment interventions for individuals with GAD

Description of five new species of hysterocinetian ciliates (Ciliophora, Hysterocinetidae), endocommensal in a terrestrial oligochaete of the genus Alma from Cameroon

International audienceStudies on five new species of hysterocinetian ciliates, endocommensal within a terrestrial oligochaete from the genus Alma (Cameroon), reveal the existence of three distinct types of cytoskeletal topography within their adhesive apparatus. In the first topographical type, four superimposed antagonistic strata of skeletal fibres that correspond to the arrangement observed in the genus Ptychostomum, Stein 1860 are found. The second topographical type is characterized by the existence of an unorganized field of fibrillar structures forming a single dense mass in the central part of the sucker. For this, a new genus is created: Ptychostomoides, Nana, Fokam, Ntoungwa et al. n. g. The third type present in the genus Proptychostomoides, Nana, Fokam, Ntoungwa et al. n. g. differs from the latter by the existence of a bare patch within the central region of the adhesive apparatus. This new evidence of morphological diversification within the Hysterocinetidae supports a new approach to the systematics of this group

Distribution of Astomatia Schewiakoff, 1896 and Hysterocinetidae Diesing, 1866 (Ciliophora, Oligohymenophora) along the digestive tract of Alma emini (Oligochaete, Glossoscolecidae) is correlated with physico-chemical parameters

International audienceThe paper demonstrates the influence of physico-chemical parameters on the distribution of endocommensal ciliates through the gut of the earthworm Alma emini. We measured physico-chemical parameters of the intestinal liquid extracted with the vacuum aspiration technique and concomitantly recorded biological parameter (species abundance). Furthermore, correlation analysis between physico-chemical parameters and biological parameter was performed in different compartments. In the foregut, among the eleven species of Astomatia recorded, correlation was significant between Metaracoelophrya intermedia, Coelophrya roquei and Water Content (WC = 46.94 ± 7.77%). In the midgut, among the nine species of Hysterocinetidae recorded, a significant correlation was observed between Metaptychostomum ebebdae, Ptychostomum macrostomum and Electric Conductivity (EC = 84.55 ± 12.94 μS/ cm). In the same compartment, a significant correlation was also observed between Ptychostomum macrostomum and Total Dissolved Substance (TDS = 16.20 ± 3.46%). In the hindgut, eight species of Astomatia were found, among which significant correlation was obtained between Coelophrya roquei and Hydrogen potential (pH = 7.35 ± 0.16). In the same compartment, taking into account the eleven species of Hysterocinetidae recorded, a significant correlation was also obtained between Ptychostomum macrostomum and pH; Ptychostomum commune and WC (28.84 ± 3.97%). These results suggest that each part of the digestive tract of A. emini can be considered as a set of natural microhabitats in which certain physico-chemical factors generate ecological niches suitable for one or another group of species