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Operational experience and performance of the Silicon Vertex Detector after the first long shutdown of Belle II
No full textInternational audienceIn 2024, the Belle II experiment resumed data taking after the Long Shutdown 1, which was required to install a two-layer pixel detector and upgrade accelerator components. We describe the challenges of this shutdown and the operational experience thereafter. With new data, the silicon-strip vertex detector (SVD) confirmed the high hit efficiency, the large signal-to-noise ratio, and the excellent cluster position resolution. In the coming years, the SuperKEKB peak luminosity is expected to increase to its target value, resulting in a larger SVD occupancy caused by beam background. Considerable efforts have been made to improve SVD reconstruction software by exploiting the excellent SVD hit-time resolution to determine the collision time and reject off-time particle hits. A novel procedure to group SVD hits event-by-event, based on their time, has been developed using the grouping information during reconstruction, significantly reducing the fake rate while preserving the tracking efficiency. The front-end chip (APV25) is operated in the multi-peak mode, which reads six samples. A 3/6-mixed acquisition mode, based on the timing precision of the trigger, reduces background occupancy, trigger dead-time, and data size. Studies of the radiation damage show that the SVD performance will not seriously degrade during the lifetime of the detector, despite moderate radiation-induced increases in sensor current and strip noise
Global mapping of thioredoxin interacting proteins in<i>Neurospora crassa</i>
No full textThioredoxins (Trx) are essential thiol-oxidoreductases that regulate redox homeostasis by reducing oxidized cysteines in a wide range of target proteins. However, the Trx system and other redox regulation mechanisms remain poorly characterized in saprotrophic filamentous fungi. Here, we identified the components of theNeurospora crassaTrx system and uncovered potential redox-regulated proteins using Trx affinity chromatography. Genome search identified three Trx and a single thioredoxin reductase that we named TRX1, TRX2 TRX3 and TRR. Notably, TRX1 carries a C-terminal disordered extension of unknown function, conserved in two ascomycete taxa (LeotiomycetesandSordariomycetes). Using recombinant cysteine-to-serine mutants of each Trx, we performed affinity chromatography and identified 1,998 proteins - approximately 19% of theN. crassaproteome. To rank the putative Trx targets, we applied a fold enrichment metric, comparing protein abundance before and after affinity chromatography. The average fold enrichment was four, with values reaching up to 117 for the most enriched protein, a DEAD/DEAH box helicase. Among the top-enriched proteins, we identified homologs of known human and plant Trx targets, like peroxiredoxins, as well as 93 transcription factors and 38 kinases. Additional potential Trx targets encompass, ubiquitination-related enzymes, Fe-S cluster assembly proteins, phospholipases, exonucleases, and chitin synthases. Moreover, components of multiprotein complexes were co-purified, reflecting both direct Trx interactions and indirect co-association. Overall, this study provides a global map of potential redox regulated proteins and Trx targets inN. crassa, laying the ground for future investigations into redox signaling in filamentous fungi
Evaluating Quercus pollen as a valuable archive of past UV-B levels in the Central Mediterranean: Insights from comparative infrared spectroscopy analyses
No full textInternational audienceThe relative abundance of ultraviolet-absorbing compounds (UACs) in pollen and spore exine increases with prolonged and higher exposure to ultraviolet B (UV-B) radiation. This relationship has been extensively studied via transmission Fourier-transform infrared microspectroscopy (transmission micro-FTIR), primarily in Lycopodium spores and airborne Pinus pollen. However, traditional transmission micro-FTIR methods are prone to infrared light scattering and interference, resulting in spectral deformations and reduced reproducibility. Additionally, bisaccate pollen, like Pinus, can travel long distances and may not accurately reflect local UV-B levels. This study compares transmission and attenuated total reflection (ATR) micro-FTIR methods to assess their reproducibility and investigates Quercus pollen as a potential local UV-B proxy in the Central Mediterranean. Samples containing fresh (in situ), trapped (in mosses), and fossilized (from Holocene sediments) pollen grains were subjected to various chemical treatments, after which the macromolecular composition of single and clustered grains was characterized. Results show that ATR micro-FTIR yields significantly more reproducible data than transmission micro-FTIR, demonstrating the suitability of this method for systematic chemo-palynological studies. Quercus ilex pollen consistently display UAC-related absorption bands across modern and fossil samples, and treatment with hydrochloric acid, hydrofluoric acid, and sodium hydroxide does not significantly alter these signatures. A comparison with fresh and trapped Q. cerris and Q. pubescens pollen further supports these findings. These results suggest that relative UAC concentrations in modern and fossil Quercus exine likely reflect accumulated UV-B dosage, pinpointing Quercus pollen as a valuable local UV-B proxy for reconstructing past UV-B levels in the Central Mediterranea
Diffusive gradient in thin film for ultra-trace methylmercury measurements in the coastal and open sea
No full textInternational audienceMonomethylmercury (MMHg) is a potent neurotoxin causing neurodevelopmental delays and cardiovascular and immunological issues. Human exposure primarily occurs through seafood consumption due to MMHg bioaccumulation and biomagnification from seawater into marine organisms. Determining MMHg in seawater at ultratrace concentrations poses logistical and analytical challenges. Diffusive Gradient in Thin-film (DGT) samplers represent a promising solution, which captures time-averaged concentrations by preconcentrating in situ MMHg over a defined exposure time. DGT manufactured with 3-mercaptopropyl-functionalized silica (3MFS) in agarose and polyacrylamide gels were tested and compared for the determination of MMHg present in open ocean and coastal waters. Different elution methods using acidic thiourea were tested to reach precise, accurate and quantitative elution of MMHg from the binding gel. We found that polyacrylamide-3MFS binding gels display a higher elution efficiency (94 ± 3 %), precision and better handling compared to agarose-3MFS gels (41 ± 6 %). A unique mooring line installed in the South Western Tropical Pacific Ocean, provided monthly DGT-MMHg concentrations over a year showing potential seasonal differences in MMHg concentrations ranging between 18 and 106 fM. DGT were also deployed in shallow Peruvian coastal waters, exhibiting higher MMHg concentrations (170 ± 97, n = 26) with typical benthopelagic gradients. DGT-MMHg concentrations were in good agreement with discrete water samples analyzed by reference methods using isotope dilution. DGTs offer complementary advantages over oceanographic cruises, notably in situ preconcentration, low blanks, minimal logistical requirements and cost-effectiveness. DGTs represent a valuable tool for studying the marine MMHg cycle for evaluating the implementation of the Minamata Convention
Calvino entre quatre yeux
No full textInternational audienceLa qualité de spectateur, d'observateur ou de visionnaire constituent l'essence même de l'activité intellectuelle pour Calvino, et finalement l'essence de son écriture. Nous revenons sur cette qualité (dans le sillage des travaux de M. Belpoliti) à travers l'analyse de quelques passages-clés. Finalement, pour Calvino, voir est plus important que savoir. Mais s'agit-il seulement de déceler ce qui existe hors de soi ? Rien n'est moins sûr. Car il s'agit de voir, mais aussi de se voir : par son regard sur les choses, toujours, Calvino regarde Calvino. En regardant l'art des autres il est surtout attentif à ce qui, dans l'oeuvre vue, correspond à sa propre façon de faire oeuvre ; en regardant l'univers qui l'entoure, il se cherche, il est à l'affût de sa façon de penser l'univers
On a theorem of François Robert
No full textA well-known theorem by François Robert expresses the degenerated character of a synchronous Boolean finite dynamical system, in the case where the associated regulatory graph does not contain any circuit: all states of the system go towards a single fixed point. We present a large family of updating modes of Boolean models with the same particularity
Chapter 3 : Regulatory and Institutional Entrepreneurship: A Cross-Review of Law & Management Insights
No full textInternational audienceThe concept of “regulatory entrepreneurship” was coined by Pollman and Barry to characterize the business strategies that change existing regulatory frameworks to increase future opportunities or maintain current business activities. The rapid expansion of this stream of literature not only echoes the copious news items concerning lobbying operations, but also the rise of platform business models, operating in legal grey areas and whose influence strategies are still controversial. From this perspective, scholars from both law and business management backgrounds have endeavored to describe the different strategies deployed by regulatory entrepreneurs, their implementation process as well as the institutional conditions favoring their emergence. In this chapter, as a response, we the author offers a cross-literature review of these concepts of ‘regulatory entrepreneurship’ and “institutional entrepreneurship.” This systemic review on institutional entrepreneurship enables us to unpacks its main conceptual properties, in comparison with regulatory entrepreneurship, and presents four areas of cross-fertilization: understanding agency, power dynamics, hybridization processes, and the complexity of institutional change. We The chapter also argues that future research should further explore the dynamic interaction between different strategies promoted by institutional entrepreneurs, considering that regulatory entrepreneurship appears as embedded in a wider complex network of institutional initiatives. Accordingly, this chapter offers a research agenda to build upon the complementarities of those literatures
Mapping the Vanished Han Networks of Bosnia: The Use of GIS to Visualize Local Road Systems in an Ottoman Context
No full textInternational audienceThis article addresses the use of a Geographic Information System (GIS) for the study of an Ottoman road network at a local scale, over the long term. Taking Bosnia between the sixteenth and nineteenth centuries as a case study, I aim to shed light on a little examined context that is lacking the monumental material remains that usually guide the study of historical Islamic road systems. I adopt a spatial history methodology by following a regressive approach as well as cross-referencing late nineteenth-century maps and earlier travel narratives to visualize several scenarios for the Bosnian road network during the Ottoman period. Following a brief discussion of GIS potentialities and prerequisites, this article turns to the selection of the han (caravanserai) as is its focus and offers a step-by-step description of the approach that was used
Direct demonstration of time-reversal-symmetry-breaking spin injection from a compensated magnet
No full textThe injection, propagation and detection of spin currents are essential physical processes in spintronics. So far, the separation of charge and spin currents was facilitated by the electrical spin injection from a ferromagnet (FM) or the injection by a relativistic spin Hall effect. The devices employed are lateral spin valves comprising spatially separated injection and detection electrodes, connected by a spin-propagation channel. The time-reversal symmetry (TRS) breaking FM spin injection is realized in a geometry with an electrical bias applied between the injection electrode and the channel and is modelled by a conserved spin-polarized drift current. In contrast, the spin injection by the T-symmetric relativistic spin Hall mechanism is driven by an electrical bias applied across the injection electrode alone, and is modelled by a non-conserved spin current transverse to the applied bias. In this work, we use a lateral spin valve with a Mn5Si3 injection electrode to directly demonstrate a TRS-breaking spin injection from a compensated magnet with a vanishing net magnetization. Specifically, the TRS-breaking is demonstrated by the fact that switching between time-reversed states of the compensated magnet changes the detected spin signal. Moreover, the TRS-breaking nature of the spin injection is observed in both experimental geometries with the different electrical biasing, while using the same detection electrode. We show that this unconventional spin-injection is consistent with different magnitudes and propagation angles of electrical currents in the spin-up and spin-down channel in a d-wave altermagnet. Here our symmetry analysis and first-principles calculations are based on the compensated collinear altermagnetic order which has provided a comprehensive microscopic interpretation of earlier structural, magnetic, and anomalous Hall and Nernst measurements in Mn5Si3 thin films