Détection de modulations linéaires de fréquence par traitement d'image sur la distribution de Wigner-Ville

Le but de cet article est de donner une nouvelle formulation du problème de détection dans le plan temps-fréquence en se basant sur la distribution de Wigner-Ville. Il s'agit ici de considérer la représentation temps-fréquence d'un signal comme une image sur laquelle il est possible de déterminer une technique de décision et d'estimation s'appuyant sur des méthodes propres au traitement d'image telles que l'ouverture morphologique, l'intercorrélation d'images et la transformée de Hough. Nous appliquons ces procédures de détection dans le cas de signaux composés de modulations linéaires de fréquence et nous les comparons par l'intermédiaire du tracé de leurs courbes COR

Functional Correction of Type VII Collagen Expression in Dystrophic Epidermolysis Bullosa

Functional defects in type VII collagen, caused by premature termination codons on both alleles of the COL7A1 gene, are responsible for the severe autosomal recessive types of the skin blistering disease, recessive dystrophic epidermolysis bullosa (RDEB). The full-length COL7A1 complementary DNA (cDNA) is about 9kb, a size that is hardly accommodated by therapeutically used retroviral vectors. Although there have been successful attempts to produce functional type VII collagen protein in model systems of RDEB, the risk of genetic rearrangements of the large repetitive cDNA sequence may hamper the clinical application of full-length COL7A1 cDNA in the human system. Therefore, we used trans-splicing to reduce the size of the COL7A1 transcript. Retroviral transduction of RDEB keratinocytes with a 3′ pre-trans-splicing molecule resulted in correction of full-length type VII collagen expression. Unlike parental RDEB keratinocytes, transduced cells displayed normal morphology and reduced invasive capacity. Moreover, transduced cells showed normal localization of type VII collagen at the basement membrane zone in skin equivalents, where it assembled into anchoring fibril-like structures. Thus, using trans-splicing we achieved correction of an RDEB phenotype in vitro, which marks an important step toward its application in gene therapy in vivo.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclu

Studii preliminare privind cultura plantelor legumicole în ghivece şi containere

This paper presents a literature review of the vegetable growing in pots and containers. Growing vegetables in this system it is known for a long time in the countries of Western Europe and in some areas of our country. Adopting this system in Romania requires in-depth studies regarding: the suitable species, the type of pots and soil recipes needed, crop establishment and maintenance (fertilizers aplication, irrigation) and, in some cases, optimization of the certain referring to light and placement of pots and containers. This cultivation system is spread mainly in peri-urban areas were the interest among gardeners to grow their own crops and secure their vegetable needs is high and has a favorable environment. Vegetable plants cultivated in pots and containers present a large diversity worldwide but, within this diversity, the climatic conditions from our country must be appropriate for an efficient activity

Anemone bleaching impacts the larval recruitment success of an anemone-associated fish

In marine environments, mutualisms such as those between corals or sea anemones and their algal symbionts (Symbiodiniaceae) play a key role for supporting surrounding biodiversity. However, as the breakdown of the mutualism between corals and/or anemones and Symbiodiniaceae (i.e. bleaching) become increasingly frequent and severe, the risk of losing the additional species that rely on them may also increase. While the effects of anemone bleaching on the biology and ecology of anemone-associated fishes have been the subject of recent research, relatively little is known about the impacts that anemone bleaching might have on the recruitment of larval fish. Here, we report that climate change-induced anemone bleaching impairs a secondary mutualism between anemones and an anemone-associated fish species, the threespot dascyllus (Dascyllus trimaculatus). Field-based monitoring over a 1-year period showed anemones that bleached experienced decreased recruitment of larval D. trimaculatus compared to those that did not bleach, with abundances of newly settled D. trimaculatus three times lower in bleached versus unbleached anemones. A visual choice experiment showed that this pattern is associated with fish being less attracted to bleached anemones, and a predation experiment demonstrated that fish associated with bleached anemones experienced higher mortality compared to those associated with unbleached anemones. These results suggests that the decreased recruitment of D. trimaculatus observed in bleached anemones may be driven by hampered pre-settlement (habitat selection) and post-settlement (survival to predation) processes for larval D. trimaculatus in bleached hosts. This study highlights the risk of cascading mutualism breakdowns in coral reefs as conditions deteriorate and stresses the importance of protecting these mutualisms for the maintenance of coral reef biodiversity

Cercetari privind comportarea unor specii legumicole în ghivece şi containere

The paper presents the research results regarding the evaluation of morphological, physiological and production characteristics in some vegetable plants grown in pots and containers. The vegetable plants studiedwere: cherry tomatoes, sweet peppers, climbing beans, dwarf beans, oregano and lovage, and for pot culture: hot peppers, basil, salad, thyme, dill and parsley. Remarkable results were obtained for the following vegetable species: cherry tomatoes 1656.0 g / pl ant andpepper 2305g / pl for container culture, and for pot culture the results were: hot pepper, 351.3g / pl and salad 250.0 g / pl

Exposure to agricultural pesticide impairs visual lateralization in a larval coral reef fish

Lateralization, i.e. the preferential use of one side of the body, may convey fitness benefits for organisms within rapidly-changing environments, by optimizing separate and parallel processing of different information between the two brain hemispheres. In coral reef-fishes, the movement of larvae from planktonic to reef environments (recruitment) represents a major life-history transition. This transition requires larvae to rapidly identify and respond to sensory cues to select a suitable habitat that facilitates survival and growth. This \u27recruitment\u27 is critical for population persistence and resilience. In aquarium experiments, larval Acanthurus triostegus preferentially used their right-eye to investigate a variety of visual stimuli. Despite this, when held in in situ cages with predators, those larvae that previously favored their left-eye exhibited higher survival. These results support the "brain\u27s right-hemisphere" theory, which predicts that the right-eye (i.e. left-hemisphere) is used to categorize stimuli while the left-eye (i.e. right-hemisphere) is used to inspect novel items and initiate rapid behavioral-responses. While these experiments confirm that being highly lateralized is ecologically advantageous, exposure to chlorpyrifos, a pesticide often inadvertently added to coral-reef waters, impaired visual-lateralization. This suggests that chemical pollutants could impair the brain function of larval fishes during a critical life-history transition, potentially impacting recruitment success

Arena3D: visualizing time-driven phenotypic differences in biological systems

<p>Abstract</p> <p>Background</p> <p>Elucidating the genotype-phenotype connection is one of the big challenges of modern molecular biology. To fully understand this connection, it is necessary to consider the underlying networks and the time factor. In this context of data deluge and heterogeneous information, visualization plays an essential role in interpreting complex and dynamic topologies. Thus, software that is able to bring the network, phenotypic and temporal information together is needed. Arena3D has been previously introduced as a tool that facilitates link discovery between processes. It uses a layered display to separate different levels of information while emphasizing the connections between them. We present novel developments of the tool for the visualization and analysis of dynamic genotype-phenotype landscapes.</p> <p>Results</p> <p>Version 2.0 introduces novel features that allow handling time course data in a phenotypic context. Gene expression levels or other measures can be loaded and visualized at different time points and phenotypic comparison is facilitated through clustering and correlation display or highlighting of impacting changes through time. Similarity scoring allows the identification of global patterns in dynamic heterogeneous data. In this paper we demonstrate the utility of the tool on two distinct biological problems of different scales. First, we analyze a medium scale dataset that looks at perturbation effects of the pluripotency regulator Nanog in murine embryonic stem cells. Dynamic cluster analysis suggests alternative indirect links between Nanog and other proteins in the core stem cell network. Moreover, recurrent correlations from the epigenetic to the translational level are identified. Second, we investigate a large scale dataset consisting of genome-wide knockdown screens for human genes essential in the mitotic process. Here, a potential new role for the gene <it>lsm14a </it>in cytokinesis is suggested. We also show how phenotypic patterning allows for extensive comparison and identification of high impact knockdown targets.</p> <p>Conclusions</p> <p>We present a new visualization approach for perturbation screens with multiple phenotypic outcomes. The novel functionality implemented in Arena3D enables effective understanding and comparison of temporal patterns within morphological layers, to help with the system-wide analysis of dynamic processes. Arena3D is available free of charge for academics as a downloadable standalone application from: <url>http://arena3d.org/</url>.</p

HACD1, a regulator of membrane composition and fluidity, promotes myoblast fusion and skeletal muscle growth

The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies, yet the underlying cellular and molecular mechanisms remain elusive. In this study, we investigate the role of HACD1/PTPLA, which is involved in the elongation of the very long chain fatty acids, in muscle fibre formation. In humans and dogs, HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscle weakness. Through analysis of HACD1-deficient Labradors, Hacd1-knockout mice, and Hacd1-deficient myoblasts, we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration. We further demonstrate that in normal differentiating myoblasts, expression of the catalytically active HACD1 isoform, which is encoded by a muscle-enriched splice variant, yields decreased lysophosphatidylcholine content, a potent inhibitor of myoblast fusion, and increased concentrations of ≥C18 and monounsaturated fatty acids of phospholipids. These lipid modifications correlate with a reduction in plasma membrane rigidity. In conclusion, we propose that fusion impairment constitutes a novel, non-exclusive pathological mechanism operating in congenital myopathies and reveal that HACD1 is a key regulator of a lipid-dependent muscle fibre growth mechanism