21 research outputs found

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    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

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    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

    Evaluation de l'intérêt du dépistage néonatal de l'hyperplasie congénitale des surrénales chez le nouveau-né prématuré

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    Malgré la contribution du dépistage néonatal de l hyperplasie congénitale des surrénales à la prévention des décès néonataux par perte de sel et des erreurs d assignation du sexe en cas d ambiguïté sexuelle, la fréquence des faux positifs chez les prématurés alimente une controverse quant à sa réalisation systématique dans cette population. L objectif de notre travail était donc d évaluer l intérêt de ce dépistage chez le nouveau-né prématuré. Tous les nouveau-nés prématurés atteints d hyperplasie congénitale des surrénales, nés en France entre le 1er janvier 1995 et le 31 décembre 2010 ont été inclus. Les critères de jugement étaient la symptomatologie liée à la maladie, et la contribution du dépistage à la mise en évidence du diagnostic. Au total, 54 nouveau-nés ont été inclus ; 68,5% d entre eux présentaient une symptomatologie liée à l hyperplasie congénitale des surrénales (37/54), dont 20% une forme sévère. Le dépistage a permis de poser le diagnostic pour 40% des prématurés de plus de 34 semaines d aménorrhée, mais pour seulement 18,7% de ceux nés entre 28 et 34 semaines d aménorrhée, et pour aucun des extrêmes prématurés. Ainsi, nous avons montré que chez les nouveau-nés de moins de 28 semaines d aménorrhée, l intérêt du dépistage de l hyperplasie congénitale des surrénales était nul, et faible pour ceux nés entre 28 et 34 semaines d aménorrhée. Dans cette population, le dépistage ne doit plus être réalisé. En revanche, il reste contributif pour les prématurés de plus deDIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

    Congenital Central Hypothyroidism Caused by a Novel IGSF1 Variant Identified in a French Family

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    International audienceIntroduction: Congenital central hypothyroidism (CCH) is a rare disorder that can be caused by X-linked mutations in the immunoglobulin superfamily member 1 (IGSF1) gene. Here, we describe four familial cases with a variable presentation due to a novel IGSF1 pathogenic variant. Case Presentation: In the index case, an investigation at birth of a suspected brain-lung-thyroid syndrome surprisingly revealed a central hypothyroidism. Next-generation sequencing uncovered a novel IGSF1 pathogenic variant: a hemizygous single base duplication (G) resulting in a premature stop codon (NM_001555.4: c.2485dup, p.Ala829Glyfs*15). Further family investigations revealed missed neonatal CCH for the older brother who presented with prolonged jaundice (thyroid stimulating hormone 3.06 mUI/L, FT4 9.4 pmol/L, FT3 4.2 pmol/L). It also led to the diagnosis of CCH at 11 months of age for the younger brother, whose thyroid function was considered normal at birth. Neuropsychological evaluations showed no cognitive impairment for the eldest two brothers, but a slightly reduced processing-speed index compared with the other parameters for the oldest. Furthermore, a maternal uncle was diagnosed with biochemical CCH at 34 years of age, despite having few symptoms, and a complete workup revealed prolactin deficiency and macroorchidism. Discussion: This report of a rare case of neonatal CCH caused by IGSF1 deficiency highlights the importance of recognizing the neonatal signs of hypothyroidism to diagnose CCH as early as possible. Our results also show the importance of performing family genetic screening if a pathogenic variant is identified, to properly monitor carriers as CCH may develop over time. We suggest that these families should be followed up in the long term to better understand the natural history of this syndrome and evaluate the need for hormone substitution

    Efficient therapy for refractory Pompe disease by mannose 6-phosphate analogue grafting on acid α-glucosidase

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    Pompe disease is a rare disorder due to deficiency of the acid a-glucosidase (GAA) treated by enzyme replacement therapy. The present authorized treatment with rhGAA, the recombinant human enzyme, provides an important benefit in the infantile onset; however, the juvenile and adult forms of the disease corresponding to > 80% of the patients are less responsive to this treatment. This resistance has been mainly attributed to an insufficiency of mannose 6-phosphate residues in rhGAA to address lysosomes through the cation-independent mannose 6-phosphate receptor (CI-M6PR). As yet, several attempts to improve the enzyme delivery by increasing the number of mannose 6-phosphate on the enzyme were poorly effective on the late onset form of the disease. Here, we show that chemical conjugation of a synthetic analogue of the mannose 6-phosphate, named AMFA, onto rhGAA improves the affinity for CI-M6PR and the uptake of the enzyme in fibroblasts and myoblasts of adult Pompe patients. More importantly, only the conjugated rhGAA-AMFA was effective in aged Pompe mice when compared to rhGAA. Weekly treatment with 5-20 mg.kg(-1) rhGAA-AMFA provided major improvements of the motor function and of the myofiber structure, whereas rhGAA was inactive. Finally, AMFA addition did not induce supplementary immune response to the enzyme. This modified enzyme, displaying a muscle recovery in aged Pompe mice that was never attained before, could be considered as a potential therapy for the late onset Pompe disease
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