XXZ spin chain at half-filling subject to local dissipation

International audienceWe study an XXZ spin chain at zero magnetization coupled to a collection of local harmonic baths at zero temperature. We map this system on a (1+1)D effective field theory using bosonization, where the effect of the bath is taken care of in an exact manner. We provide analytical and numerical evidence of the existence of two phases at zero temperature: a Luttinger liquid (LL) and an antiferromagnetic phase (AFM), separated by a Berezinsky-Kosterlitz-Thouless (BKT) phase transition. While the bath is responsible for the LL-AFM transition for subohmic baths, the LL-AFM transition for superohmic baths is due to the interactions within the spin chain

Introduction to the PanScales framework, version 0.1

International audienceIn this article, we document version 0.1 of the PanScales code for parton shower simulations. With the help of a few examples, we discuss basic usage of the code, including tests of logarithmic accuracy of parton showers. We expose some of the numerical techniques underlying the logarithmic tests and include a description of how users can implement their own showers within the framework. Some of the simpler logarithmic tests can be performed in a few minutes on a modern laptop. As an early step towards phenomenology, we also outline some aspects of a preliminary interface to Pythia, for access to its hard matrix elements and its hadronisation modules

High‐throughput untargeted screening of biotherapeutic macromolecules in equine plasma by UHPLC‐HRMS/MS : Application to monoclonal antibodies and Fc‐fusion proteins for doping control

International audienceAbstract Many innovative biotherapeutics have been marketed in the last decade. Monoclonal antibodies (mAbs) and Fc‐fusion proteins (Fc‐proteins) have been developed for the treatment of diverse diseases (cancer, autoimmune diseases, and inflammatory disorders) and now represent an important part of targeted therapies. However, the ready availability of such biomolecules, sometimes characterized by their anabolic, anti‐inflammatory, or erythropoiesis‐stimulating properties, raises concerns about their potential misuse as performance enhancers for human and animal athletes. In equine doping control laboratories, a method has been reported to detect the administration of a specific human biotherapeutic in equine plasma; but no high‐throughput method has been described for the screening without any a priori knowledge of human or murine biotherapeutic. In this context, a new broad‐spectrum screening method involving UHPLC‐HRMS/MS has been developed for the untargeted analysis of murine or human mAbs and related macromolecules in equine plasma. This approach, consisting of a “pellet digestion” strategy performed in a 96‐well plate, demonstrates reliable performances at low concentrations (pmol/mL range) with high‐throughput capability (≈100 samples/day). Targeting species‐specific proteotypic peptides located within the constant parts of mAbs enables the “universal” detection of human biotherapeutics only by monitoring 10 peptides. As proof of principle, this strategy successfully detected different biotherapeutics in spiked plasma samples, and allowed, for the first time, the detection of a human mAb up to 10 days after a 0.12 mg/kg administration to a horse. This development will expand the analytical capabilities of horse doping control laboratories towards protein‐based biotherapeutics with adequate sensitivity, throughput, and cost‐effectiveness

A gm/Id based methodology to estimate OTA requirements in low-pass discrete time Σ∆-ADCs

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Microcanonical windows on quantum operators

International audienceWe discuss a construction of a microcanonical projection WOW of a quantum operator O, its spectrum, and the retrieval of canonical many-time correlations from it

New Horizons in the Holographic Conformal Phase Transition

International audienceWe describe cosmological solutions of the holographic dilaton with the aim of exploring alternatives to the commonly studied thermal Randall-Sundrum phase transition. It is well known that the thermal transition is typically strongly first order, with the requirement of a perturbative 5D gravity theory obstructing completion of the transition. This thermal transition corresponds to nucleation of an infrared brane through the surface of an AdS-Schwarzschild horizon. The approach we study instead invokes an early epoch in which the cosmology is fully 5-dimensional, with highly relativistic brane motion, and with Rindler horizons obscuring the infrared brane at early times. Our approach corresponds, via AdS/CFT, to a non-equilibrium approach to the conformal phase transition. We comment on a class of initial conditions that generically leads to completion of the phase transition without sacrificing perturbativity of the 5D theory

Dilepton polarization as a signature of plasma anisotropy

International audienceWe propose the angular distribution of lepton pairs produced in ultrarelativistic heavy-ion collisions as a probe of thermalization of the quark-gluon plasma. We focus on dileptons with invariant masses large enough that they are produced through quark-antiquark annihilation in the early stages of the collision. The angular distribution of the lepton in the rest frame of the pair then reflects the angular distribution of quark momenta. At early times, the transverse pressure of the quark-gluon plasma is larger than its longitudinal pressure as a result of the fast longitudinal expansion, which results in an oblate lepton distribution. By constrast, direct (Drell-Yan) production by quarks and antiquarks from incoming nuclei, whose momenta are essentially longitudinal, results in a prolate distribution. As the invariant mass increases, Drell-Yan gradually becomes the dominant source of dilepton production, and the lepton distribution evolves from oblate to prolate. The invariant mass at which the transition occurs is highly sensitive to the equilibration time of the quark-gluon plasma or, equivalently, the shear viscosity over entropy ratio $\eta/s$ in the early stages of the collision

Multi-Calorimetry in Light-based Neutrino Detectors

International audienceNeutrino detectors are among the largest photonics instruments built for fundamental research. Since its inception, neutrino detection has been inexorably linked to the challenging detection of scarce photons in huge instrumented volumes. Many discoveries in neutrino physics, including the neutrino itself, are inseparable from the evolution of the detector photonics interfaces, i.e. photo-sensors and readout electronics, to yield ever higher precision and richer detection information. The measurement of the energy of neutrinos, referred to as calorimetry, is pursued today to reach permille level systematics control precision, thus leading to further innovation in specialised photonics. This publication describes a novel articulation that detectors may be endowed with multiple photonics interfaces for simultaneous light detection to yield unprecedented high-precision calorimetry. This multi-calorimetry approach opens the novel notion of dual-calorimetry detectors as an evolution from the single-calorimetry setups used over several decades for most experiments so far. The dual-calorimetry design exploits unique response synergies between photon counting and photon-integration detection systems, including correlations and cancellations between calorimetric responses, to yield the unprecedented mitigation of the dominant response systematic effects today for the possible improved design of a new generation of neutrino experiments

Unraveling the interplay between root exudates, microbiota, and rhizosheath formation in pearl millet

International audienceBackgroundThe rhizosheath, a cohesive soil layer firmly adhering to plant roots, plays a vital role in facilitating water and mineral uptake. In pearl millet, rhizosheath formation is genetically controlled and influenced by root exudates. Here, we investigated the impact of root exudates on the microbiota composition, interactions, and assembly processes, and rhizosheath structure in pearl millet using four distinct lines with contrasting soil aggregation abilities.ResultsUtilizing 16S rRNA gene and ITS metabarcoding for microbiota profiling, coupled with FTICR-MS metabonomic analysis of metabolite composition in distinct plant compartments and root exudates, we revealed substantial disparities in microbial diversity and interaction networks. The ß-NTI analysis highlighted bacterial rhizosphere turnover driven primarily by deterministic processes, showcasing prevalent homogeneous selection in root tissue (RT) and root-adhering soil (RAS). Conversely, fungal communities were more influenced by stochastic processes. In bulk soil assembly, a combination of deterministic and stochastic mechanisms shapes composition, with deterministic factors exerting a more pronounced role. Metabolic profiles across shoots, RT, and RAS in different pearl millet lines mirrored their soil aggregation levels, emphasizing the impact of inherent plant traits on microbiota composition and unique metabolic profiles in RT and exudates. Notably, exclusive presence of antimicrobial compounds, including DIMBOA and H-DIMBOA, emerged in root exudates and RT of low aggregation lines.ConclusionsThis research underscores the pivotal influence of root exudates in shaping the root-associated microbiota composition across pearl millet lines, entwined with their soil aggregation capacities. These findings underscore the interconnectedness of root exudates and microbiota, which jointly shape rhizosheath structure, deepening insights into soil–plant-microbe interactions and ecological processes shaping rhizosphere microbial communities. Deciphering plant–microbe interactions and their contribution to soil aggregation and microbiota dynamics holds promise for the advancement of sustainable agricultural strategies

Geoarchaeology of open-air sites of the Foz do Chapecó area in the upper Uruguay river, southern Brazil

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