21 research outputs found
Genome variation in tick infestation and cryptic divergence in Tunisian indigenous sheep
BACKGROUND: Ticks are obligate haematophagous ectoparasites considered second to mosquitos as vectors and reservoirs of multiple pathogens of global concern. Individual variation in tick infestation has been reported in indigenous sheep, but its genetic control remains unknown. RESULTS: Here, we report 397 genome-wide signatures of selection overlapping 991 genes from the analysis, using ROH, LR-GWAS, XP-EHH, and F(ST), of 600 K SNP genotype data from 165 Tunisian sheep showing high and low levels of tick infestations and piroplasm infections. We consider 45 signatures that are detected by consensus results of at least two methods as high-confidence selection regions. These spanned 104 genes which included immune system function genes, solute carriers and chemokine receptor. One region spanned STX5, that has been associated with tick resistance in cattle, implicating it as a prime candidate in sheep. We also observed RAB6B and TF in a high confidence candidate region that has been associated with growth traits suggesting natural selection is enhancing growth and developmental stability under tick challenge. The analysis also revealed fine-scale genome structure indicative of cryptic divergence in Tunisian sheep. CONCLUSIONS: Our findings provide a genomic reference that can enhance the understanding of the genetic architecture of tick resistance and cryptic divergence in indigenous African sheep. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12864-022-08321-1
Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower RhĂ´ne Valley, France
On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower RhĂ´ne Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional CĂ©venne fault system in a context of present-day compressional tectonics
Calibration of subsurface dynamic parameters and fault geometry from surface fault rupture observations: an example from the shallow 2019 Mw4.9 Le Teil (France) event.
International audienceWe investigate the impact of several friction, stress drop and fault geometry on surface fault rupture amount and patterns. Based on a shallow reverse surface rupturing Mw4.9 earthquake which occurred in southeastern France in November 2019, and models derived from data collected (InSAR, waveforms), we set up a rupture scenario that is consistent with the observations. From this kinematic scenario we constrain the dynamic parameters of the deeper part of the rupture (300-2 km depth), while we test the shallow part parameters (<300m). The surface rupture produced by the different models are then compared to the surface deformation patterns and amplitude. We show that the shallow surface layers are likely slip-strengthening, but also that the surface rupture is not a passive marker of the deeper rupture process: they are both linked. The frictional behavior (Dc, Stress drop, weakening or strengthening) directly modulates the amount of surface rupture. Dynamic rupture history notably differs from the kinematic model, although the friction evolution of the first was directly derived from the second. Adding a secondary structure in the northern part improves significantly the surface rupture fit, as well as the rupture history. Finally, such a shallow reverse fault earthquake seen through its dynamics emphasizes a puzzling question: what is the absolute level of stress on a seismogenic fault so close to the surface
Enthalpic lattice Boltzmann formulation for heat conduction during melting of PCMs with embedded solid blocks with different thermophysical properties
International audienc
An enthalpy-based lattice Boltzmann formulation for unsteady convection-diffusion heat transfer problems in heterogeneous media
International audienceIn this paper, we propose a direct extension of a previous work presented by Hamila et al. [1 R. Hamila, M. Nouri, S. Ben Nasrallah, and P. Perré, Int. J. Heat Mass Transfer, vol. 100, pp. 728–736, 2016.[CrossRef], [Web of Science ®], [Google Scholar]] dealing with the simulation of conjugate heat transfer by conduction in heterogeneous media. In [1 R. Hamila, M. Nouri, S. Ben Nasrallah, and P. Perré, Int. J. Heat Mass Transfer, vol. 100, pp. 728–736, 2016.[CrossRef], [Web of Science ®], [Google Scholar]] a novel enthalpy-based lattice Boltzmann (LB) formulation was successfully simulated in several conjugate heat transfer problems by conduction. We propose testing this enthalpic LB formulation in solving convection-diffusion heat transfer problems in heterogeneous media. The main idea of this formulation is to introduce an extra source term, avoiding any additional treatment of the distribution functions at the interface. Continuity of temperature and normal heat flux at the interface is satisfied automatically. The performance of the present method is successfully validated by comparison to the control volume methods (CVMs) solutions of several heat convection-diffusion problems in heterogeneous media
A three-dimensional enthalpic lattice Boltzmann formulation for convection–diffusion heat transfer problems in heterogeneous media
International audienceIn this paper, an enthalpic lattice Boltzmann method formulation for 3D unsteady convection-diffusion heat transfer problems is used to overcome discontinuity issues in heterogeneous media. The new formulation is based on the appearance of a source term added to the collision step. The major achievement of the proposed enthalpic LB formulation is avoiding any interface treatments or geometry considerations even when dealing with complex geometries. The performance of the present method is tested for several three-dimensional convection-diffusion problems. Comparisons are made with the control volume method, and numerical results show excellent agreements
Enthalpic lattice Boltzmann formulation for unsteady heat conduction in heterogeneous media
International audienceIn this paper, we propose an enthalpic lattice Boltzmann formulation for heat transfer in heterogeneous media. This formulation leads to the appearance of a source term, which introduces the jump conditions at the interface between two phases or components, with different thermal properties. It conserves conductive heat flux, which makes it suitable for modeling heat conduction in multiphase and multi-component systems. This approach is simple to implement and can be easily applied to simulate heat transfer with complex and time dependent interfaces, efficiently. It does not require any specific treatment dependent on interface topology. It is also independent on the choice of lattice. This approach is validated by comparisons with analytical and numerical results of several test problems with flat and curved interfaces. Both 2- and 3-dimensional conduction transfer problems were simulated. The obtained results show excellent agreements with reference solutions
In vitro biological properties and health benefits of a novel sulfated polysaccharide isolated from Cymodocea nodosa
Abstract Background During the last few decades, there has been a growing interest in the search for novel bioactive compounds from marine origins. Methods The present study is the first to determine the molecular characterization which it was deposited in the genebank database, to investigate and evaluate the biological properties of sulfated polysaccharide from Cymodocea nodosa (CNSP) seagrass. Results The results revealed that CNSP had high activity in total antioxidant assay (59.03 mg ascorbic acid equivalents/g extract), reducing power (OD = 0.3), DPPH radical scavenging (IC50 = 1.22 mg/ml) and ABTS radical scavenging (IC50 = 1.14 mg/ml). It was also noted to exhibit antimicrobial activity against a wide range of microorganisms, with important inhibition zones. The results revealed that CNSP was able to inhibit the proliferation of Hela cell lines with a dose-dependent manner. Conclusion Overall, the results presented in this study demonstrate that CNSP has several attractive antioxidant, antimicrobial and antiproliferative properties with potential benefits towards health
Rapid response to the Mw 4.9 earthquake of November 11, 2019 in Le Teil, Lower RhĂ´ne Valley, France
International audienc