Etude du satut phylogénétique du bovin Kouri du lac Tchad à l'aide de marqueurs moléculaires

Le polymorphisme de 25 systèmes de marqueurs génétiques autosomaux(11 systèmes de groupes sanguins, 5 locus de lactoprotéines et 9 microsatellites) a été analysé dans un échantillon de la population de bovins Kouri du lac Tchad provenant de la zone en bordure du lac et d'iles localisées dans la préfecture de Bol. Les résultats obtenus, ainsi que les données déjà acquises sur différentes populations de taurins et de zébus africains et sur les races françaises, ont été traités par analyse factorielle des correspondances et par des méthodes de classification pour tenter de préciser le statut phylogénétique du Kouri. Selon cette étude, basée sur des marqueurs autosomaux, le Kouri se rapproche plus des zébus que des taurins africains alors que, dépourvu de bosse et possédant le chromosome Y submétacentrique de Bos taurus, il est classé normalement parmi les taurins. Il reste à évaluer la validité de diverses hypothèses explicatives, d'ailleurs non exclusives, différant par l'ancienneté postulée de l'apport de gènes de zébus : parenté du Kouri avec le Sanga du Sud de l'Afrique, introgression du zébu lors de son expansion sur le continent à partir du VIIIe siècle après J.-C., ou métissages, à l'époque moderne, avec les zébus entourant le bassin du lac Tchad. (Résumé d'auteur

Solid-state laser system for laser cooling of Sodium

We demonstrate a frequency-stabilized, all-solid laser source at 589 nm with up to 800 mW output power. The laser relies on sum-frequency generation from two laser sources at 1064 nm and 1319 nm through a PPKTP crystal in a doubly-resonant cavity. We obtain conversion efficiency as high as 2 W/W^2 after optimization of the cavity parameters. The output wavelength is tunable over 60 GHz, which is sufficient to lock on the Sodium D2 line. The robustness, beam quality, spectral narrowness and tunability of our source make it an alternative to dye lasers for atomic physics experiments with Sodium atoms

A Generalized Multistep Dynamic (GMD) TOPMODEL

There is a lack of Ordinary Differential Equation (ODE) formulations in numerical hydrology, contributing to the lack of application of canned adaptive timestep solvers; hence the continued dominance of fixed (e.g., Euler) timestep techniques despite their fundamental problems. In this paper, we reformulate Dynamic-TOPMODEL into a constraint-handling ODE form and use MATLAB's advanced adaptive ODE-solvers to solve the resulting system of equations. For wider applicability, but based on existing research and/or first principles, we developed Generalized Multistep Dynamic TOPMODEL which includes: iso-basin spatial discretization, diffusion wave routing, depth-dependent overland flow velocity, relaxing the assumption of water-table parallelism to the ground surface, a power-law hydraulic conductivity profile, new unsaturated zone flux, and a reference frame adjustment. To demonstrate the model we calibrate it to a peat catchment case study, for which we also test sensitivity to spatial discretization. Our results suggest that (a) a five-fold improvement in model runtime can result from adaptive timestepping; (b) the additional iso-basin discretization layer, as a way to further constrain spatial information where needed, also improves performance; and (c) the common-practice arbitrary Topographic Index (TI) discretization substantially alters calibrated parameters. More objective and physically constrained (e.g., top-down) approaches to TI classification may be needed

Subduction controls the distribution and fragmentation of Earth’s tectonic plates

International audienceThe theory of plate tectonics describes how the surface of the Earth is split into an organized jigsaw of seven large plates 1 of similar sizes and a population of smaller plates, whose areas follow a fractal distribution 2,3. The reconstruction of global tectonics during the past 200 My 4 suggests that this layout is probably a long-term feature of our planet, but the forces governing it are unknown. Previous studies 3,5,6 , primarily based on statistical properties of plate distributions, were unable to resolve how the size of plates is determined by lithosphere properties and/or underlying mantle convection. Here, we demonstrate that the plate layout of the Earth is produced by a dynamic feedback between mantle convection and the strength of the lithosphere. Using 3D spherical models of mantle convection with plate-like behaviour that match the plate size-frequency distribution observed for Earth, we show that subduction geometry drives the tectonic fragmentation that generates plates. The spacing between slabs controls the layout of large plates, and the stresses caused by the bending of trenches, break plates into smaller fragments. Our results explain why the fast evolution in small back-arc plates 7,8 reflects the dramatic changes in plate motions during times of major reorganizations. Our study opens the way to use convection simulations with plate-like behaviour to unravel how global tectonics and mantle convection are dynamically connected

Microbiota derived short chain fatty acids promote histone crotonylation in the colon through histone deacetylases

The recently discovered histone post-translational modification crotonylation connects cellular metabolism to gene regulation. Its regulation and tissue-specific functions are poorly understood. We characterize histone crotonylation in intestinal epithelia and find that histone H3 crotonylation at lysine 18 is a surprisingly abundant modification in the small intestine crypt and colon, and is linked to gene regulation. We show that this modification is highly dynamic and regulated during the cell cycle. We identify class I histone deacetylases, HDAC1, HDAC2, and HDAC3, as major executors of histone decrotonylation. We show that known HDAC inhibitors, including the gut microbiota-derived butyrate, affect histone decrotonylation. Consistent with this, we find that depletion of the gut microbiota leads to a global change in histone crotonylation in the colon. Our results suggest that histone crotonylation connects chromatin to the gut microbiota, at least in part, via short-chain fatty acids and HDACs

Neoliberalism and the Ideological Construction of Equity Beliefs

Researchers across disciplines, including psychology, have sought to understand how people evaluate the fairness of resource distributions. Equity, defined as proportionality of rewards to merit, has dominated the conceptualization of distributive justice in psychology; some scholars have cast it as the primary basis on which distributive decisions are made. The present article acts as a corrective to this disproportionate emphasis on equity. Drawing on findings from different subfields, we argue that people possess a range of beliefs about how valued resources should be allocated—beliefs that vary systematically across developmental stages, relationship types, and societies. By reinvigorating notions of distributive justice put forth by the field’s pioneers, we further argue that prescriptive beliefs concerning resource allocation are ideological formations embedded in socioeconomic and historical contexts. Fairness beliefs at the micro level are thus shaped by those beliefs’ macro-level instantiations. In a novel investigation of this process, we consider neoliberalism, the globally dominant socioeconomic model of the past 40 years. Using data from more than 160 countries, we uncover evidence that neoliberal economic structures shape equity-based distributive beliefs at the individual level. We conclude by advocating an integrative approach to the study of distributive justice that bridges micro- and macro-level analyses. © The Author(s) 2022

2D Qubit Placement of Quantum Circuits using LONGPATH

In order to achieve speedup over conventional classical computing for finding solution of computationally hard problems, quantum computing was introduced. Quantum algorithms can be simulated in a pseudo quantum environment, but implementation involves realization of quantum circuits through physical synthesis of quantum gates. This requires decomposition of complex quantum gates into a cascade of simple one qubit and two qubit gates. The methodological framework for physical synthesis imposes a constraint regarding placement of operands (qubits) and operators. If physical qubits can be placed on a grid, where each node of the grid represents a qubit then quantum gates can only be operated on adjacent qubits, otherwise SWAP gates must be inserted to convert non-Linear Nearest Neighbor architecture to Linear Nearest Neighbor architecture. Insertion of SWAP gates should be made optimal to reduce cumulative cost of physical implementation. A schedule layout generation is required for placement and routing apriori to actual implementation. In this paper, two algorithms are proposed to optimize the number of SWAP gates in any arbitrary quantum circuit. The first algorithm is intended to start with generation of an interaction graph followed by finding the longest path starting from the node with maximum degree. The second algorithm optimizes the number of SWAP gates between any pair of non-neighbouring qubits. Our proposed approach has a significant reduction in number of SWAP gates in 1D and 2D NTC architecture.Comment: Advanced Computing and Systems for Security, SpringerLink, Volume 1

Mupirocin resistance in Staphylococcus aureus: A systematic review and meta-analysis

Objectives: Staphylococcus aureus is one of the most common pathogens causing nosocomial and community-acquired infections associated with high morbidity and mortality. Mupirocin has been increasingly used for treatment of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) infections. The aim of this study was to determine the prevalence of mupirocin-resistant S. aureus (MuRSA), mupirocin-resistant MRSA (MuRMRSA), high-level MuRSA (HLMuRSA) and high-level MuRMRSA (HLMuRMRSA) worldwide. Methods: Online databases including Medline, Embase and Web of Science were searched (2000�2018) to identify studies addressing the prevalence of MuRSA, MuRMRSA, HLMuRSA and HLMuRMRSA. STATA v. software was used to interpret the data. Results: Of the 2243 records identified from the databases, 30 and 63 studies fulfilled the eligibility criteria for MuRSA and MuRMRSA, respectively. Finally, 27 and 60 studies were included separately for HLMuRSA and HLMuRMRSA, respectively. The analyses revealed pooled and averaged prevalences of MuRSA, MuRMRSA, HLMuRSA and HLMuRMRSA of 7.6 95% confidence interval (CI) 6.2�9.0%, 13.8% (95% CI 12.0�15.6%), 8.5% (95% CI 6.3�10.7%) and 8.1% (95% CI 6.8�9.4%), respectively. Conclusion: Overall, these results show a global increase in the prevalence of HLMuRSA and HLMuRMRSA among clinical S. aureus isolates over time. However, there was only a significant increase in the prevalence of MuRMRSA compared with the other categories, especially MuRSA. Since mupirocin remains the most effective antibiotic for MSSA and MRSA decolonisation both in patients and healthcare personnel, a reduction of its effectiveness presents a risk for invasive infection. Monitoring of mupirocin resistance development remains critical. © 2019 International Society for Antimicrobial Chemotherap

Constructing TI-Friendly Substitution Boxes Using Shift-Invariant Permutations

The threat posed by side channels requires ciphers that can be efficiently protected in both software and hardware against such attacks. In this paper, we proposed a novel Sbox construction based on iterations of shift-invariant quadratic permutations and linear diffusions. Owing to the selected quadratic permutations, all of our Sboxes enable uniform 3-share threshold implementations, which provide first order SCA protections without any fresh randomness. More importantly, because of the shift-invariant property, there are ample implementation trade-offs available, in software as well as hardware. We provide implementation results (software and hardware) for a four-bit and an eight-bit Sbox, which confirm that our constructions are competitive and can be easily adapted to various platforms as claimed. We have successfully verified their resistance to first order attacks based on real acquisitions. Because there are very few studies focusing on software-based threshold implementations, our software implementations might be of independent interest in this regard