154 research outputs found
HMAS: enabling seamless collaboration between drones, quadruped robots, and human operators with efficient spatial awareness
Heterogeneous robots equipped with multi-modal sensors (e.g., UAV, wheeled
and legged terrestrial robots) provide rich and complementary functions that
may help human operators to accomplish complex tasks in unknown environments.
However, seamlessly integrating heterogeneous agents and making them interact
and collaborate still arise challenging issues. In this paper, we define a ROS
2 based software architecture that allows to build incarnated heterogeneous
multi-agent systems (HMAS) in a generic way. We showcase its effectiveness
through a scenario integrating aerial drones, quadruped robots, and human
operators (see https://youtu.be/iOtCCticGuk). In addition, agent spatial
awareness in unknown outdoor environments is a critical step for realizing
autonomous individual movements, interactions, and collaborations. Through
intensive experimental measurements, RTK-GPS is shown to be a suitable solution
for achieving the required locating accuracy
Learning Constrained Edit State Machines
International audienceLearning the parameters of the edit distance has been increasingly studied during the past few years to improve the assessment of similarities between structured data, such as strings, trees or graphs. Often based on the optimization of the likelihood of pairs of data, the learned models usually take the form of probabilistic state machines, such as pair-Hidden Markov Models (pair-HMM), stochastic transducers, or probabilistic deterministic automata. Although the use of such models has lead to significant improvements of edit distance-based classification tasks, a new challenge has appeared on the horizon: How integrating background knowledge during the learning process? This is the subject matter of this paper in the case of (input,output) pairs of strings. We present a generalization of the pair-HMM in the form of a constrained state machine, where a transition between two states is driven by constraints fulfilled on the input string. Experimental results are provided on a task in molecular biology, aiming to detect transcription factor binding sites
Le « Scholarship of teaching and Learning » SOTL. Proposition dâun cadre pour lâaccompagnement des enseignants par les conseillers pĂ©dagogiques.
Le « Scholarship of teaching and Learning » SOTL. Proposition dâun cadre pour lâaccompagnement des enseignants par les conseillers pĂ©dagogiques.
Seismic swarms in Tricastin, lower RhĂŽne Valley (France): review of historical and instrumental seismicity and models
Une <i>culina</i> de type « pompĂ©ien » en territoire lyonnais : lâespace culinaire de la <i>villa</i> de Goiffieux Ă Saint-Laurent-dâAgny (RhĂŽne)
International audienceThe excavations conducted on the site of Goiffieux at Saint-Laurent-dâAgny, between 2008 and 2011, brought to light a vast villa belonging to the colony of Lugdunum and occupied as soon as its foundation in the years 30-40 BC. Mainly devoted to viticulture, this establishment is equipped at the beginning of our era with private baths, associated to a small well-preserved kitchen. In this article functional equipment (hob, bench) are analysed, as well as food waste found in this area (fauna, plant remains and pottery assemblages). The kitchen is linked to water devices that we can identify to a water mill and latrines. Its masonry hob equipped with vault reserves of fuel, and fed by the adjacent praefurnium, is a characteristic of urban culinae known in Campania and there is no equivalent in the Tres Galliae rural space. It attests to a strong influence of Italic architectural patterns, which goes together with the adoption of new culinary practices.Les fouilles menĂ©es de 2008 Ă 2011 sur le site de Goiffieux, Ă Saint-Laurent-dâAgny, y ont mis au jour une vaste villa rattachĂ©e Ă la colonie de Lugdunum et occupĂ©e dĂšs sa phase de fondation, dans les annĂ©es 30-40 av. J.-C. Principalement dĂ©diĂ© Ă la viticulture, ce domaine de rendement se dote au dĂ©but de notre Ăšre de bains privĂ©s, associĂ©s Ă une petite cuisine aux vestiges bien conservĂ©s. Cet article sâintĂ©resse Ă ses amĂ©nagements fonctionnels (table Ă feu, paillasse) aussi bien quâaux reliefs alimentaires retrouvĂ©s dans cet espace (faune, carporestes et assemblages cĂ©ramiques). La cuisine est associĂ©e Ă des Ă©quipements hydrauliques, que lâon propose dâidentifier Ă un petit moulin hydraulique et Ă un espace de latrine. Sa table Ă feu maçonnĂ©e, dotĂ©e de rĂ©serves Ă combustible voĂ»tĂ©es et alimentĂ©e par le praefurnium adjacent, est caractĂ©ristique des culinae urbaines reconnues en Campanie et ne possĂšde aucun Ă©quivalent dans les campagnes des Trois Gaules. Elle tĂ©moigne dâune forte influence des modĂšles architecturaux italiques, qui va de pair avec lâadoption de nouveaux modes de prĂ©paration alimentaire
Hot Carrier Solar Cell: From Simulation to Devices
International audienceSingle junction III-V heterostructures based devices could overtake the Shockley-Queisser limit if thermalisation of photogenerated carriers can be strongly limited as in the hot carrier solar cell concept. Previous modelling and experiments have shown the interest of Multiple Quantum Wells heterostructures in the antimonide system and the importance of very thin structures. In this paper we report new data on the thermalisation rates in antimonide and phosphide heterostructures measured at ambient temperature. For the first time electrical control of hot carrier population is performed on hot carrier heterostructures device
Intestinal antiinflammatory effect of 5-aminosalicylic acid is dependent on peroxisome proliferatorâactivated receptor-Îł
5-aminosalicylic acid (5-ASA) is an antiinflammatory drug widely used in the treatment of inflammatory bowel diseases. It is known to inhibit the production of cytokines and inflammatory mediators, but the mechanism underlying the intestinal effects of 5-ASA remains unknown. Based on the common activities of peroxisome proliferatorâactivated receptor-Îł (PPAR-Îł) ligands and 5-ASA, we hypothesized that this nuclear receptor mediates 5-ASA therapeutic action. To test this possibility, colitis was induced in heterozygous PPAR-Îł+/â mice and their wild-type littermates, which were then treated with 5-ASA. 5-ASA treatment had a beneficial effect on colitis only in wild-type and not in heterozygous mice. In epithelial cells, 5-ASA increased PPAR-Îł expression, promoted its translocation from the cytoplasm to the nucleus, and induced a modification of its conformation permitting the recruitment of coactivators and the activation of a peroxisome-proliferator response elementâdriven gene. Validation of these results was obtained with organ cultures of human colonic biopsies. These data identify PPAR-Îł as a target of 5-ASA underlying antiinflammatory effects in the colon
Aphanomyces euteiches Cell Wall Fractions Containing Novel Glucan-Chitosaccharides Induce Defense Genes and Nuclear Calcium Oscillations in the Plant Host Medicago truncatula
[EN] N-acetylglucosamine-based saccharides (chitosaccharides) are components of microbial cell walls and act as molecular signals
during host-microbe interactions. In the legume plant Medicago truncatula, the perception of lipochitooligosaccharide signals
produced by symbiotic rhizobia and arbuscular mycorrhizal fungi involves the Nod Factor Perception (NFP) lysin motif receptor-like
protein and leads to the activation of the so-called common symbiotic pathway. In rice and Arabidopsis, lysin motif receptors are
involved in the perception of chitooligosaccharides released by pathogenic fungi, resulting in the activation of plant immunity. Here
we report the structural characterization of atypical chitosaccharides from the oomycete pathogen Aphanomyces euteiches, and
their biological activity on the host Medicago truncatula. Using a combination of biochemical and biophysical approaches, we show
that these chitosaccharides are linked to ÎČ-1,6-glucans, and contain a ÎČ-(1,3;1,4)-glucan backbone whose ÎČ-1,3-linked glucose
units are substituted on their C-6 carbon by either glucose or N-acetylglucosamine residues. This is the first description of this type
of structural motif in eukaryotic cell walls. Glucan-chitosaccharide fractions of A. euteiches induced the expression of defense
marker genes in Medicago truncatula seedlings independently from the presence of a functional Nod Factor Perception protein.
Furthermore, one of the glucan-chitosaccharide fractions elicited calcium oscillations in the nucleus of root cells. In contrast to the
asymmetric oscillatory calcium spiking induced by symbiotic lipochitooligosaccharides, this response depends neither on the Nod
Factor Perception protein nor on the common symbiotic pathway. These findings open new perspectives in oomycete cell wall
biology and elicitor recognition and signaling in legumes.SIThis work is part of the âLaboratoire dâExcellenceâ (LABEX) entitled TULIP (ANR -10-LABX-41); it was funded by the RĂ©gion Midi-PyrĂ©nĂ©es, the CNRS (PhD grant INEE 36 to AN), and the French Agence Nationale de la Recherche (ANR-08-BLAN-0208-01 âSympasignalâ)
The rise and fall of the ancient northern pike master sex determining gene
The understanding of the evolution of variable sex determination mechanisms across taxa requires comparative studies among closely related species. Following the fate of a known master sex-determining gene, we traced the evolution of sex determination in an entire teleost order (Esociformes). We discovered that the northern pike (Esox lucius) master sex-determining gene originated from a 65 to 90 million-year-old gene duplication event and that it remained sex-linked on undifferentiated sex chromosomes for at least 56 million years in multiple species. We identified several independent species- or population-specific sex determination transitions, including a recent loss of a Y-chromosome. These findings highlight the diversity of evolutionary fates of master sex-determining genes and the importance of population demographic history in sex determination studies. We hypothesize that occasional sex reversals and genetic bottlenecks provide a non-adaptive explanation for sex determination transitions
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