Searching for the light dark gauge boson in GeV-scale experiments

We study current constraints and search prospects for a GeV scale vector boson at a range of low energy experiments. It couples to the Standard Model charged particles with a strength <= 10^-3 to 10^-4 of that of the photon. The possibility of such a particle mediating dark matter self-interactions has received much attention recently. We consider searches at low energy high luminosity colliders, meson decays, and fixed target experiments. Based on available data, searches both at colliders and in meson decays can discover or exclude such a scenario if the coupling strength is on the larger side. We emphasize that a dedicated fixed target experiment has a much better potential in searching for such a gauge boson, and outline the desired properties of such an experiment. Two different optimal designs should be implemented to cover the range of coupling strength 10^-3 to 10^-5, and < 10^-5 of the photon, respectively. We also briefly comment on other possible ways of searching for such a gauge boson.Comment: 33 pages, 5 figures; v2: corrected discussion of Upsilon decays, updates to discussion of fixed-target experiments and QED constraints, numerous minor changes, references added; v3: typo corrected relative to the JHEP published versio

Private trade and monopoly structures : the East India Companies and the commodity trade to Europe in the eighteenth century

Our research is about the trade in material goods from Asia to Europe over this period, and its impact on Europe’s consumer and industrial cultures. It entails a comparative study of Europe’s East India Companies and the private trade from Asia over the period. The commodities trade was heavily dependent on private trade. The historiography to date has left a blind spot in this area, concentrating instead on corruption and malfeasance. Taking a global history approach we investigate the trade in specific consumer goods in many qualities and varieties that linked merchant communities and stimulated information flows. We set out how private trade functioned alongside and in connection with the various European East India companies; we investigate how this changed over time, how it drew on the Company infrastructure, and how it took the risks and developed new and niche markets for specific Asian commodities that the Companies could not sustain

Atlantic Leatherback Migratory Paths and Temporary Residence Areas

BACKGROUND: Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. METHODOLOGY/PRINCIPAL FINDINGS: Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. CONCLUSIONS/SIGNIFICANCE: Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly influenced by environmental conditions. This high degree of behavioural plasticity in Atlantic leatherback turtles makes species-targeted conservation strategies challenging and stresses the need for a larger dataset (>100 individuals) for providing general recommendations in terms of conservation

Smart Input Space Sampling Combined with Kriging-Partial Least Square Regression for EMC Risk Analysis at PCB Level with Many Variables

International audienceThis article describes an advanced methodology for training surrogate models (SMs) in order to study the sensitivity of many geometrical parameters of printed circuit boards (PCBs) for a quicker investigation of routing rules regarding potential electromagnetic compatibility (EMC) or signal integrity (SI) issues. This methodology consists in two steps. First, it retains only the sensitive parameters of the input space that mostly explain the several output observations. Second, it consists in training iteratively several competing SMs, selecting the most efficient one, regarding training time and/or accuracy. Here, the Kriging-partial least square Regression (K-PLS) is identified as a relevant method for the considered case study, which consists of a 17-parameter multiple outputs crosstalk scenario. An extreme value analysis is provided as an outcome for a possible adjustment of design rules. © 2023 IEEE

Efficient EMC Risk Analysis of PCB Using Iterative Surrogate-Model Enrichment and Morris Sensitivity Analysis

International audienceThis document describes a new methodology for building surrogate model dedicated to EMC analysis of printed circuit boards. Stochastic approaches have recently showed their interests for EMC phenomena simulations because of their ability to replace costly computations. The proposed method is composed of two process stages. The first one is a pre-processing step which consists in filtering inputs that are not significant regarding output variations. The second one consists in an iterative learning technique of the surrogate model avoiding the requirement for prior determination of the sample size. The method is tested from a representative scenario of an EMC problem. The gain in computation time offered by the method makes it possible to build surrogate models more efficiently

Temperature mapping in a two-phase water-steam horizontal flow

International audienc

Human reliability analysis for reducing risk in an LPG treatment and storage plant

International audienceVIRTHUALIS is a European Research Project on Industrial Safety with the overall objective of evaluating and, where possible, reducing the risk level in production plants and storage sites with the integration of Virtual Reality and Human Factors methods. For the estimation of Human Error Probabilities a specific tool has been developed named the Fuzzy Probability Estimator (FPE). The application of the FPE tool in a specific case study is presented in this paper. The specific case study aims at analyzing the start-up of a gas turbine used to drive the compressor of the butane/propane refrigeration section of an LPG storage and treatment complex. The example chosen is the case of oil leakage at the coupling of the turbine with the compressor. Specifically detailed through bow-tie analysis, the action it refers to is the operator visual check of the coupling area. Performance Shaping Factors (PSFs) that influence operators' reliability have been identified and rated for the specific site according to expert judgment and on site observations from human factor experts.The PSFs are linked to specific task deviations and, in relation to those and to the need to observe how they influence the task, the design of VIRTHUALIS simulation experiments is performe

Review of ceftazidime-avibactam for the treatment of infections caused by pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that causes a range of serious infections that are often challenging to treat, as this pathogen can express multiple resistance mechanisms, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) pheno-types. Ceftazidime–avibactam is a combination antimicrobial agent comprising ceftazidime, a third-generation semisynthetic cephalosporin, and avibactam, a novel non-β-lactam β-lactamase inhibitor. This review explores the potential role of ceftazidime–avibactam for the treatment of P. aeruginosa infections. Ceftazidime–avibactam has good in vitro activity against P. aeruginosa relative to com-parator β-lactam agents and fluoroquinolones, comparable to amikacin and ceftolozane–tazobactam. In Phase 3 clinical trials, ceftazidime–avibactam has generally demonstrated similar clinical and microbiological outcomes to comparators in patients with complicated intra-abdominal infections, complicated urinary tract infections or hospital-acquired/ventilator-associated pneumonia caused by P. aeruginosa. Although real-world data are limited, favourable outcomes with ceftazidime–avibactam treatment have been reported in some patients with MDR and XDR P. aeruginosa infections. Thus, ceftazidime–avibactam may have a potentially important role in the management of serious and complicated P. aeruginosa infections, including those caused by MDR and XDR strains. © 2021 by the authors. Licensee MDPI, Basel, Switzerland