Resistance of Omicron subvariants BA.2.75.2, BA.4.6 and BQ.1.1 to neutralizing antibodies

Convergent evolution of SARS-CoV-2 Omicron BA.2, BA.4 and BA.5 lineages has led to the emergence of several new subvariants, including BA.2.75.2, BA.4.6. and BQ.1.1. The subvariants BA.2.75.2 and BQ.1.1 are expected to become predominant in many countries in November 2022. They carry an additional and often redundant set of mutations in the spike, likely responsible for increased transmissibility and immune evasion. Here, we established a viral amplification procedure to easily isolate Omicron strains. We examined their sensitivity to 6 therapeutic monoclonal antibodies (mAbs) and to 72 sera from Pfizer BNT162b2-vaccinated individuals, with or without BA.1/BA.2 or BA.5 breakthrough infection. Ronapreve (Casirivimab and Imdevimab) and Evusheld (Cilgavimab and Tixagevimab) lost any antiviral efficacy against BA.2.75.2 and BQ.1.1, whereas Xevudy (Sotrovimab) remained weakly active. BQ.1.1 was also resistant to Bebtelovimab. Neutralizing titers in triply vaccinated individuals were low to undetectable against BQ.1.1 and BA.2.75.2, 4 months after boosting. A BA.1/BA.2 breakthrough infection increased these titers, which remained about 18-fold lower against BA.2.75.2 and BQ.1.1, than against BA.1. Reciprocally, a BA.5 breakthrough infection increased more efficiently neutralization against BA.5 and BQ.1.1 than against BA.2.75.2. Thus, the evolution trajectory of novel Omicron subvariants facilitated their spread in immunized populations and raises concerns about the efficacy of most currently available mAbs.N

The noise-lovers: cultures of speech and sound in second-century Rome

This chapter provides an examination of an ideal of the ‘deliberate speaker’, who aims to reflect time, thought, and study in his speech. In the Roman Empire, words became a vital tool for creating and defending in-groups, and orators and authors in both Latin and Greek alleged, by contrast, that their enemies produced babbling noise rather than articulate speech. In this chapter, the ideal of the deliberate speaker is explored through the works of two very different contemporaries: the African-born Roman orator Fronto and the Syrian Christian apologist Tatian. Despite moving in very different circles, Fronto and Tatian both express their identity and authority through an expertise in words, in strikingly similar ways. The chapter ends with a call for scholars of the Roman Empire to create categories of analysis that move across different cultural and linguistic groups. If we do not, we risk merely replicating the parochialism and insularity of our sources.Accepted manuscrip

POTOMAC : vers un modèle réaliste de secondaires et rétrodiffusés pour le multipactor

International audienceCharacterized by a very fast growth of the electron population in vacuum of Radio-Frequency (RF) devices, the multipactor effect has been widely studied during the past decades. As it limits the transmitted RF power and may degrade RF devices, its understanding is primordial. Multipactor simulation tools give accurate results in the simplest cases, but are less accurate for advanced configurations: complex geometries, dielectric materials, presence of magnetic fields, etc. In such cases, an accurate modelling of the electron emission phenomena becomes essential. We extended a one-dimension electron emission (EE) model to three dimensions. The obtained model is compared to measured electron emission yields. The impact of this new model on the simulated multipactor threshold of parallel plane wave-guide is also investigated

A numerical and theoretical study of the multipactor appearance in the presence of a DC parallel electric field

International audienceIn this paper, we study the appearance of the multipactor in a simple system with a bottom plate holding a static potential Vd. We developed a numerical model to compute the evolution of the multipactor threshold as a function of the potential. We identify the nature of the resonant modes that appear at different Vd using resonance theory. Then, we use it to compute the theoretical threshold of the structure. As we use a very simplistic electron emission model to identify the multipactor modes, we compute the threshold in a more realistic configuration in a second step

A three-dimensional Dionne model for multipactor simulations

International audienceThe multipactor phenomenon is characterized by a very fast growth of the electronic population in Radio-Frequency (RF) devices under vacuum. As this effect limits the transmissible RF power and can harm RF systems, it has been widely studied during the last decades. Due to the high cost of experimental tests, simulation tools are heavily used to predict the threshold of multipactor growth. However, their reliability is limited for complex configurations, e.g. when dielectrics or magnetic fields are present. A crucial element of these multipactor simulations is the secondary-emission model. Dionne model is able to model both metals and dielectrics secondary emission but is one-dimension only. As the three-dimensional aspect is essential for complex configurations, the Dionne model is extended do three-dimensions. Measurements of the total electron emission yield have been carried out at the ONERA and shows a good agreement for low-impact energy and low-impact angle electrons, which is relevant in multipactor simulations

Multipactor sensitivity to Total Electron Emission Yield and TEEY models accuracy, studies made with a small gap waveguide structure.

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Le procès au service de la démocratie ?

Projet de recherche (bourse ERC - Starting Grant 2023 - SUEDEM)From the 1990s, in Europe, an increasing number of groups - including minorities - have resorted to legal proceedings due to an inability to make themselves meaningfully heard, when they sought to defend their interests, within the democratic system. Certain scholars named these legal procedures “strategic litigation” (SL). For years, legal scholars dismissed this litigation, prompt to criticise it as an instrumentalisation of justice, especially when such litigation was used by socially marginalised groups. However, as this SL has become more abundant, transcending the field of minorities to be used in the environmental sphere in particular – with striking European victories –, it is evident that it is playing a central role in our democracies. Simultaneously, we are observing a loss of confidence in traditional institutions. Where voting in referenda or elections often reduces citizens’ agency to expressing a binary choice, and where participation and consultation mechanisms remain limited in their areas of application and effects, collective action in the area of justice seems to increase citizens’ agency and enable them to participate in the exercise of power. The SUEDEM project (SUing for European DEMocracy) aims to understand if and how SL contributes to democracy. It will do so through fulfilling three aims: 1) to gain a clearer understanding of the concept of SL with a democratic aim, through literature analysis and field studies, including undertaking litigation (though SL has already been examined in sector-based studies, no holistic study of the phenomenon exists); 2) to establish the legitimacy of SL and its actors, by demonstrating their central contribution to democracy; 3) to promote “democratic strategic litigation” (DSL) by offering instruments to be used by legislative assemblies (for example, a European directive proposal), assessors and financers (effectiveness indicators for DSL) and NGOs (a practical guide to DSL)

Le procès au service de la démocratie ?

Projet de recherche (bourse ERC - Starting Grant 2023 - SUEDEM)From the 1990s, in Europe, an increasing number of groups - including minorities - have resorted to legal proceedings due to an inability to make themselves meaningfully heard, when they sought to defend their interests, within the democratic system. Certain scholars named these legal procedures “strategic litigation” (SL). For years, legal scholars dismissed this litigation, prompt to criticise it as an instrumentalisation of justice, especially when such litigation was used by socially marginalised groups. However, as this SL has become more abundant, transcending the field of minorities to be used in the environmental sphere in particular – with striking European victories –, it is evident that it is playing a central role in our democracies. Simultaneously, we are observing a loss of confidence in traditional institutions. Where voting in referenda or elections often reduces citizens’ agency to expressing a binary choice, and where participation and consultation mechanisms remain limited in their areas of application and effects, collective action in the area of justice seems to increase citizens’ agency and enable them to participate in the exercise of power. The SUEDEM project (SUing for European DEMocracy) aims to understand if and how SL contributes to democracy. It will do so through fulfilling three aims: 1) to gain a clearer understanding of the concept of SL with a democratic aim, through literature analysis and field studies, including undertaking litigation (though SL has already been examined in sector-based studies, no holistic study of the phenomenon exists); 2) to establish the legitimacy of SL and its actors, by demonstrating their central contribution to democracy; 3) to promote “democratic strategic litigation” (DSL) by offering instruments to be used by legislative assemblies (for example, a European directive proposal), assessors and financers (effectiveness indicators for DSL) and NGOs (a practical guide to DSL)

Electron emission under uniform magnetic field of conductor materials used for spatial and fusion applications.

International audienc