Reducing two-level system dissipations in 3D superconducting Niobium resonators by atomic layer deposition and high temperature heat treatment

Superconducting qubits have arisen as a leading technology platform for quantum computing which is on the verge of revolutionizing the world's calculation capacities. Nonetheless, the fabrication of computationally reliable qubit circuits requires increasing the quantum coherence lifetimes, which are predominantly limited by the dissipations of two-level system (TLS) defects present in the thin superconducting film and the adjacent dielectric regions. In this paper, we demonstrate the reduction of two-level system losses in three-dimensional superconducting radio frequency (SRF) niobium resonators by atomic layer deposition (ALD) of a 10 nm aluminum oxide Al2O3 thin films followed by a high vacuum (HV) heat treatment at 650 {\deg}C for few hours. By probing the effect of several heat treatments on Al2O3-coated niobium samples by X-ray photoelectron spectroscopy (XPS) plus scanning and conventional high resolution transmission electron microscopy (STEM/HRTEM) coupled with electron energy loss spectroscopy (EELS) and (EDX) , we witness a dissolution of niobium native oxides and the modification of the Al2O3-Nb interface, which correlates with the enhancement of the quality factor at low fields of two 1.3 GHz niobium cavities coated with 10 nm of Al2O3

Combined in silico and experimental identification of the Pyrococcus abyssi H/ACA sRNAs and their target sites in ribosomal RNAs

How far do H/ACA sRNPs contribute to rRNA pseudouridylation in Archaea was still an open question. Hence here, by computational search in three Pyrococcus genomes, we identified seven H/ACA sRNAs and predicted their target sites in rRNAs. In parallel, we experimentally identified 17 Ψ residues in P. abyssi rRNAs. By in vitro reconstitution of H/ACA sRNPs, we assigned 15 out of the 17 Ψ residues to the 7 identified H/ACA sRNAs: one H/ACA motif can guide up to three distinct pseudouridylations. Interestingly, by using a 23S rRNA fragment as the substrate, one of the two remaining Ψ residues could be formed in vitro by the aCBF5/aNOP10/aGAR1 complex without guide sRNA. Our results shed light on structural constraints in archaeal H/ACA sRNPs: the length of helix H2 is of 5 or 6 bps, the distance between the ANA motif and the targeted U residue is of 14 or 15 nts, and the stability of the interaction formed by the substrate rRNA and the 3′-guide sequence is more important than that formed with the 5′-guide sequence. Surprisingly, we showed that a sRNA–rRNA interaction with the targeted uridine in a single-stranded 5′-UNN-3′ trinucleotide instead of the canonical 5′-UN-3′ dinucleotide is functional

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Isolement spatial des sources d'infection chez la fourmi Myrmica rubra: un mécanisme essentiel de l'immunité sociale.

L’eusocialité a conduit à l’émergence de comportements coopératifs permettant bien souvent aux insectes sociaux de dominer leur niche écologique. Mais cette haute organisation sociale a également diverses contraintes dont un risque sanitaire accru dû à la proximité physique et génétique des individus. Les sociétés d’insectes ont donc développé des mécanismes « d’immunité sociale » pour limiter leur exposition aux pathogènes ainsi que la transmission de maladies entre les membres du groupe. Durant cette thèse, nous nous sommes intéressés d’une part aux changements induits par une infection de contact chez les individus, dans leurs comportements, leurs interactions sociales et leur distribution spatiale ;et d’autre part aux mécanismes collectifs de gestion des risques sanitaires, particulièrement lors du processus de rejet de déchets contaminés et de sélection d’un site de nidification. Au niveau individuel, les ouvrières contaminées s’isolent spatialement à mesure que l’infection progresse, pour mourir loin de leur nid. Ce retrait spontané de la colonie n’est pas dû à un rejet actif par leurs congénères mais résulte d’une perte progressive d’attraction des individus infectés pour les stimuli liés au nid, un phénomène amplifié par des déficits locomoteurs juste avant leur mort. Ce comportement d’isolement spatial des individus moribonds apparait donc comme un mécanisme prophylactique simple mais efficace pour réduire l’exposition globale de la colonie aux pathogènes ainsi que les coûts de gestion des cadavres. Ces résultats ouvrent de nouvelles perspectives sur les mécanismes sous-jacents à ce comportement prophylactique, souvent perçu comme un retrait actif et altruiste des individus en fin de vie. Au niveau des comportements sanitaires collectifs, nous avons étudié l’impact de la taille de la population sur la capacité des colonies à gérer des déchets infectés à l’intérieur de leur nid. Nous avons montré que les grandes colonies résistent mieux à la présence de cette source infectieuse, notamment grâce à une plus grande rapidité dans le processus de rejet. De façon inattendue, certaines petites colonies développent une stratégie sanitaire alternative en quittant collectivement le nid contaminé, démontrant la plasticité phénotypique des stratégies hygiéniques dans les sociétés d’insectes. De plus, une identité coloniale semble exister dans l’efficacité des rejets de déchets, ce qui suggère l’importance des caractéristiques intrinsèques aux colonies dans leur profil hygiéniste. Lors du processus de nidification, notre étude a révélé une forte influence de la contamination du substrat sur la dynamique de creusement des nids ainsi que sur la morphologie de leurs patterns finaux. Tandis qu’une partie des colonies ont évité clairement les sols contaminés par les spores du champignon, d’autres ont montré au contraire une attraction, ce qui démontre la capacité des colonies à discriminer les substrats en fonction de leur pathogénicité. Cela suggère également que les colonies préférant les sites contaminés tirent certains avantages adaptatifs en termes de conditions abiotiques favorables ou d’amorçage immunitaire. Tous ces résultats confirment le rôle crucial des mécanismes d’isolement spatial des sources d’infections dans les stratégies prophylactiques et hygiéniques d’une société d’insectes. Cela soulève également d’intéressantes questions sur l’impact du génome, du milieu de vie et des expériences antérieures des colonies dans leur capacité à percevoir les risques sanitaires et à réguler leurs défenses sociales.Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Influence du facteur démographique sur la gestion des risques sanitaires chez la fourmi Myrmica rubra.

info:eu-repo/semantics/nonPublishe

Isolation of fungus-infected ants: a spontaneous or a nestmate-driven behavior?

info:eu-repo/semantics/nonPublishe

Knowledge diasporas for development: a shrinking space for scepticism

International audienceThis paper deals with the contribution of diaspora knowledge networks to the development of home countries as a major potential brain gain. Although some questions were recently raised about the consistency, viability and efficiency of the diaspora option, the latest studies tend to validate its role in the development of knowledge intensive activities at home. The Asian experience (China and India), the current expansion of their highly skilled expatriate associations, their real intensity of activity as well as their responsiveness to policy factors, confirm the diaspora option. The case of the development of the Information Technology industry in India demonstrates the active involvement of the diaspora. Its integration into the global market has gone far beyond the sole effect of reputation enhancer, a minimal positive role often attributed to the diaspora. In fact, the active role of the Indian diaspora, a creative mediator rather than a passive intermediary in these processes, has changed strategic balance and geopolicy. The diaspora factor is indeed part of the knowledge transfer to the Indian IT industry that helps it to move up on the value chain. The circulation exemplified by diasporas justifies shifting from binary/dichotomical explanations (host versus home countries benefits), to the analysis of mediation processes at work in non-zero sum game analysis

Prophylaxis through reduced mobility and loss of attraction for social cues in ants

info:eu-repo/semantics/nonPublishe

Spatial distancing by fungus-exposed Myrmica ants is prompted by sickness rather than contagiousness

The ecological success of ants relies on their high level of sociality and cooperation between genetically related nestmates. However, these group-living insects suffer from elevated risks of disease outbreak in the whole nest. To face this sanitary challenge, social and spatial distancing of pathogen-exposed individuals from susceptible nestmates appear to be simple, although efficient, ways to limit the propagation of contact-transmitted pathogens. Here we question whether spatial distancing in Myrmica rubra ants is an active response of diseased individuals that correlates with their level of infectiousness. We contaminated foragers with spores of Metarhizium brunneum entomopathogenic fungus. We daily tracked the location of these pathogen-exposed individuals and we analyzed their movement patterns until their death on the 5th day post-contamination. Quite unexpectedly, we found that contagious individuals, whose body was covered with infectious spores, did not reduce their mobility nor stayed far away from larvae in order to limit pathogen transmission to healthy nestmates. Spatial distancing occurred later when diseased individuals were no longer contagious because spores had penetrated their body. These sick ants mainly stayed outside the nest, were less mobile and showed a shift from a superdiffusive to subdiffusive walking pattern. Furthermore, these diseased ants did not actively head towards directions that were opposite to the nest entrance. This study found no evidence for early spatial distancing by contaminated M.rubra workers that would fit to the actual risk of colony-wide contagion. Coupled to a lower mobility and area-reduced walking patterns, the late distancing of moribund individuals appears to be a symptom of sickness resulting from fungus-induced physical and physiological dysfunctions. Besides questioning the truly altruistic nature of death in isolation in this system (and potentially others), we discuss about the ecological and physiological constraints that explain the absence of early distancing when some ant species are exposed to pathogens.SCOPUS: ar.jinfo:eu-repo/semantics/publishe