50 research outputs found
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two
locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino
detector off the French coast will instrument several megatons of seawater with
photosensors. Its main objective is the determination of the neutrino mass
ordering. This work aims at demonstrating the general applicability of deep
convolutional neural networks to neutrino telescopes, using simulated datasets
for the KM3NeT/ORCA detector as an example. To this end, the networks are
employed to achieve reconstruction and classification tasks that constitute an
alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT
Letter of Intent. They are used to infer event reconstruction estimates for the
energy, the direction, and the interaction point of incident neutrinos. The
spatial distribution of Cherenkov light generated by charged particles induced
in neutrino interactions is classified as shower- or track-like, and the main
background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and
maximum-likelihood reconstruction algorithms previously developed for
KM3NeT/ORCA are provided. It is shown that this application of deep
convolutional neural networks to simulated datasets for a large-volume neutrino
telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
Continental Vertebrates of Upper Cretaceous from Provence (Southeastern France)
L’étude menée dans cette thèse, révise les faunes continentales du Crétacé supérieur (Campanien, Maastrichtien) de Provence (Bouches-du-Rhône et Var). Les recherches ont été menées sur plusieurs points : établir un inventaire précis des gisements paléontologiques, établir une liste faunique exhaustive pour chaque gisement, corréler les différents sites dans la stratigraphie générale et étudier les caractéristiques de la faune provençale. L’inventaire des sites fossilifères provençaux tient compte de plus d’une dizaine de nouveaux sites.Le recensement faunique de ces sites révèle des compositions semblables, à hauts niveaux de rangs taxinomiques. Dans le détail, elle comporte de légères variations selon l’âge des gisements, la localisation géographique et le contexte environnemental. L’actualisation des données met en évidence une richesse taxinomique bien plus importante que précédemment estimée. Le repositionnement stratigraphique des sites provençaux dans le Crétacé supérieur a été effectué à l’aide de marqueurs biostratigraphiques classiques et de l’oostratigraphie, permettant ainsi de corriger l’âge de certains sites historiques.L’examen de la paléobiodiversité provençale a tenu compte de la variabilité (intra ou interspécifique) et de la définition de nouveaux taxons. La variabilité/diversité de certains (titanosaures, Rhabdodon, théropodes ; nodosauridés) a été estimée grâce à l’utilisation de morphotypes.En caractérisant la faune provençale, ce travail pose les bases de l’étude de la faune à l’échelle de l’île ibéro-armoricaine. A l’échelle provençale, cette faune présente des caractéristiques d’une évolution en milieu insulaire avec quelques spécificités.The study led within the framework of this thesis, reports on the Upper Cretaceous continental faunae (Campanian, Maastrichtian) of Provence (Boûches-du-Rhone and Var).Researches were focused on several aspects: Establish a precise inventory of the known paleontological deposits; establish a faunal exhaustive list for each deposit, correlate the various sites in the general stratigraphy and study the characteristics of Provencal fauna. Provencal fossil inventory takes into account more than about ten new localities.The fauna inventory of all these sites reveals similar compositions at high taxonomic levels. However, in detail, this fauna contains light variations according to the age of the localities, the geographical location and the environmental context. Data updating highlights a taxonomic richness more important than previously estimated. The stratigraphic reposition of the various localities from Provence in the Upper Cretaceous was carried out by the use of classic biostratigraphic markers and oostratigraphy, which allowed correcting the age of some historical sites.The study of paleobiodiversity in Provence took into account the variability (intra or interspecific) and the definition of new taxa. The variability/diversity of some taxa (titanosaurs, Rhabdodon, theropods, nodosaurids) was estimated thanks to the use of precise morphotypes.By characterizing the fauna from Provence, this work establishes the bases of the study of the Fauna on ibero-Armorican island (which includes Provence). At the Provence scale, this fauna presents many characteristics of an evolution in island environment with some evolutionary specificities
Homogeneous and Heterogeneous Polymerization of \varepsilon-Caprolactone by Neodymium Alkoxides Prepared In Situ
International audienc
An unexpected early rhabdodontid from Europe (Lower Cretaceous of Salas de los Infantes, Burgos Province, Spain) and a Re- Examination of basal iguanodontian relationships
Disarticulated and incomplete remains from a new diminutive ornithopod are described. They come from the Cameros Basin in the north of Spain and were collected from the red clays of the Castrillo de la Reina Formation, ranging from Upper Barremian to Lower Aptian. The new ornithopod described here is slender and one of the smallest ever reported. An up-to-date phylogenetic analysis recovers this taxon as a basal iguanodontian. Its unique combination of characters makes itmore derived than slender ornithopods like Hyphilophodon and Gasparinisaura, and bring very interesting insights into the basal iguanodontian phylogeny. Though possessing a minimum of three premaxillary teeth, this taxon also bears an extensor ilio-tibialis groove on the distal part of its femur. Moreover, its dentary and maxillary teeth are unique, remarkably similar to those regarded as having a "rhabdomorphan" affinity. This unknown taxon is suggested to be a stemtaxon within Rhabdodontidae, a successful clade of basal iguanodonts from the Late Cretaceous of Europe. The Gondwanan ornithopods share the strongest affinities with this family, and we confirm Muttaburrasaurus as a sister taxon of the Rhabdodontidae within a newly defined clade, the Rhabdodontomorpha.Fil: DieudonnĂ©, Paul Emile. Universidad de Zaragoza; EspañaFil: Tortosa, Thierry. RĂ©serve Naturelle Nationale Sainte-Victoire; FranciaFil: Fernández Baldor, Fidel Torcida. Municipio de Salas de los Infantes. Museo de Dinosaurios; EspañaFil: Canudo, JosĂ© Ignacio. Universidad de Zaragoza; EspañaFil: DĂaz MartĂnez, Ignacio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte. Instituto de InvestigaciĂłn en PaleobiologĂa y GeologĂa; Argentin
Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island
International audienceThe increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km 2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 10 7 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain
New eutherian mammals from the late cretaceous of Aix en Provence Basin, south-eastern France
International audienc
List of the bones referred in the text, followed with their respective measurements and detailed information.
<p>Abbreviations: APPEND., appendicular skeleton; ONTO., ontogenetical stage; j., juvenile; subad., subadult; ad., adult; F., fused centra; nF., non-fused centra; MDS.VG, inventory number for the Vegagete specimen; N.I., non-inventoried; Fr. details, if fragmentary: fragment location onto the bone; L, length; W, width; H, height; (ant.), anterior; (post.), posterior; (prox.), proximal; (dist.), distal; NA, non-applicable. Measures are in millimeters. N.B.1: Teeth measurements are exclusively done on their crowns. N.B.2: vertebrae measurements are exclusively done on their centra.</p
Femora.
<p>The proximal extremity belonging to the largest sized individual, MDS-VG,109, is figured in A<sub>1</sub> posterior, A<sub>2</sub> lateral, and A<sub>3</sub> proximal views. The diaphysis fragment (B) belongs to the medium-sized individual and is in medial view. The distal fragments MDS-VG,135 (C), MDS-VG,132 (D), and MDS-VG,134 (E) belong respectively to the largest and two medium-sized individual. They are in posterior (C), anterior (D<sub>1</sub>/E<sub>1</sub>) and distal (D<sub>2</sub>/E<sub>2</sub>) views. Abbreviations: 4th.tr, fourth trochanter; cfl, <i>caudifemoralis</i> muscle scar; eg, extensor groove; fg flexor groove; g.tr, greater trochanter; ifg, <i>ilio-fibularis</i> muscle groove; l.tr, lesser trochanter; lcf, sulcus for the <i>ligamentum capitis femoris</i>; tr.f, <i>trochanteris fossa</i>. Scale: 1 cm.</p
Snout elements from the Vegagete taxon.
<p>(A) premaxillary fragment (non-inventoried) in labial (A<sub>1</sub>) and medial (A<sub>2</sub>) views; (B) posterior maxillary fragment (MDS-VG,9) in labial (B<sub>1</sub>) and lingual (B<sub>2</sub>) views; (C) posterior dentary fragment (MDS-VG,16/17/152) in lingual (C<sub>1</sub>), labial (C<sub>2</sub>) and occlusal (C<sub>3</sub>) views. Abbreviations: amp, anteromedial maxillary process; bp, bony process; mc, Meckelian canal; cor, coronoid insertion area; cr, curved root; dep, depression for the adductor jaw musculature; lm, labial emargination; nf, narial fossa; pal, palatin insertion area; pr, mesially bent primary ridge. Scale: 1cm.</p