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Characteristics of Gold Mineralization at the Baguiomo Gold Panning Site, Koudougou Region, Burkina Faso, West Africa

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Open Journal of Geology 2024年第1期14卷 1-18页

作者： pascal.ouiya Aziz Fayçal Tarnagda Martial Eric Fozing Ecole Normale Supérieure (ENS) Institut Sciences et Technologie (IST) Ouagadougou Burkina Faso Laboratoire Géosciences et Environnement (LaGE) Earth Sciences Department Ouagadougou Burkina Faso Department of Geology University of Dschang Dschang Cameroon

The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1B deformation. The second phase of D2B deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization.

关键词： Kwademen-Baguiomo Shear Zone Gold Panning Site Gold Mineralization Eburnian Orogeny

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Insight from Lithostructural and Aeromagnetic Data from the Léo Square Degree, Central-Western Burkina Faso

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Open Journal of Geology 2024年第1期14卷 19-28页

作者： Adama Ouédraogo Yaméogo pascal.ouiya Gounwendmanaghré Hubert Zongo Omar Akonyiré Abraham Seydoux Traoré Saga Sawadogo Séta Naba Unité de Formation et de Recherche en Sciences et Technologies Département des Sciences de la Vie et de la Terre Université Norbert Zongo Koudougou Burkina Faso Unité de Formation et de Recherche en Sciences de la Vie et de la Terre Laboratoire Géosciences et Environnement (LaGE) Département des Sciences de la Terre Université Joseph Ki-Zerbo Ouaga Burkina Faso Ecole Normale Supérieure (ENS)/Institut des Sciences et de Technologie (IST) Ouaga Burkina Faso Ecole Supérieure d’Ingénieries Université de Fada N’gourma Fada N’Gourma Burkina Faso

This study, carried out in the Léo square degree (west-central Burkina Faso) in the Palaeoproterozoic domain of the Man/Léo ridge, aims to define the shapes and positions of granitic plutons and the organisation of deformation structures using aeromagnetic data. These data have shown that there are small sub-circular granitic bodies to the north of the granitic masses in this region, and a large sub-circular granitic body to the south, around which are other smaller granitic bodies. The lineament map shows that the deformation structures are organised along three main directions and largely form these sub-circular plutonic bodies. We suggest that the granitic plutons are coalescent, pending identification of the internal structures of these granites to further refine the geodynamic model.

关键词： Burkina Faso Lineaments Belts Rocks Leo’s Leaf Granitoïd Airbornes Magnétics

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Petrographic and Geochemical Characteristics of the Granitoids in the South of Godé (North of the Square Degree of Léo-Burkina Faso, West Africa)

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International Journal of Geosciences 2024年第2期15卷 106-118页

作者： Adama Ouédraogo Yaméogo Hubert Gounwendmanaghré Zongo pascal.ouiya Omar Akonyiré Abraham Seydoux Traoré Saga Sawadogo Séta Naba Unité de Formation et de Recherche en Sciences et Technologies Département des Sciences de la Vie et de la Terre Université Norbert Zongo Koudougou Burkina Faso Unité de Formation et de Recherche en Sciences de la Vie et de la Terre Laboratoire Géosciences et Environnement (LaGE) Départe-ment des Sciences de la Terre Université Joseph Ki-Zerbo Ouaga Burkina Faso Ecole Supérieure d’Ingénieries Université de Fada N’gourma Fada N’Gourma Burkina Faso Ecole Normale Supérieure (ENS)/Institut des Sciences et de Technologie (IST) Ouaga Burkina Faso

South of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the REE spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones.

关键词： Burkina Faso Godé Man/Leo Shield Petrography Geochemistry Partial Melting Geotectonic Setting

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Petrographic and Geochemical Characteristics of the Pouni Palaeoproterozoic Formations North of the Léo Square Degree (Burkina Faso, West Africa)

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Open Journal of Geology 2024年第1期14卷 126-141页

作者： Adama Ouédraogo Yaméogo pascal.ouiya Hubert Gounwendmanaghré Zongo Omar Akonyiré Abraham Seydoux Traoré Saga Sawadogo Séta Naba Unité de Formation et de Recherche en Sciences et Technologies Département des Sciences de la Vie et de la Terre Université Norbert Zongo Koudougou Burkina Faso Unité de Formation et de Recherche en Sciences de la Vie et de la Terre Laboratoire Géosciences et Environnement (LaGE) Département des Sciences de la Terre Université Joseph Ki-Zerbo Ouaga Burkina Faso Ecole Normale Supérieure (ENS) Institut des Sciences et de Technologie (IST) Ouaga Burkina Faso Ecole Supérieure d’Ingénieries Université de Fada N’gourma Fada N’Gourma Burkina Faso

The Pouni area is made up of basalts belonging to the Boromo belt, lamprophyres and granitoids. These geological formations are similar to geological formations of the same type in other regions of the Palaeoproterozoic domain of the Man/Leo shield. This study, which focused on the petrographic and geochemical characteristics of these geological formations, led to the following main conclusions: The lamprophyres are basic plutonic rocks that cut through other geological formations. The basalt belongs to the northern part of the Borormo belt and is thought to be a relic of overthickened oceanic plateaus. There are two groups of granitoid rocks. The granodiorite has a geochemical signature close to that of Archean TTGs and is metaluminous in character. It has a low potassium content. The minor element and rare earth element spectra indicate that it could be derived from partial melting of basic magmatic rocks. Biotite granites are peraluminous and highly potassic. Minor element contents and rare earth spectra indicate that they could be derived from partial melting of felsic materials. Geotectonic diagrams show that the granitoids identified in the Pouni zone were emplaced in an active tectonic context, similar to that of present-day subduction zones.

关键词： Burkina Faso Dori Man/Léo Shield Petrography Geochemistry Partial Melting Geotectonic Context

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Long-COVID-19: the persisting imprint of SARS-CoV-2 infections on the innate immune system

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Signal Transduction and Targeted Therapy 2024年第1期9卷 12-13页

作者： Marianne Boes pascal Falter-Braun Center for Translational Immunology and Department of Pediatric Immunology University Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands Institute of Network Biology(INET) Molecular Targets and Therapeutics Center(MTTC)Helmholtz MunichNeuherbergGermany Microbe-Host Interactions Faculty of BiologyLudwig-Maximilians-Universität MünchenPlanegg-MartinsriedGermany

In a recent Cell publication,Cheong et *** how COVID-19 causes IL-6 induced epigenetic reprogramming of human immune stem cells,which causes lasting alterations in the composition and response characteristics of circulating immune cells.1 The study provides important insights into the mechanisms by which SARSCoV-2 infections impact the human immune system and is an important hook into unraveling the mechanisms of post-acute sequelae of COVID-19(PASC)commonly referred to as longCOVID.

关键词： system COV programming

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On-the-fly precision spectroscopy with a dual-modulated tunable diode laser and Hz-level referencing to a cavity

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Advanced Photonics 2024年第4期6卷 36-44页

作者： Shuangyou Zhang Toby Bi pascal Del’Haye Max Planck Institute for the Science of Light ErlangenGermany Friedrich-Alexander Universität Erlangen-Nürnberg Department of PhysicsErlangenGermany

Advances in laser spectroscopy have enabled many scientific breakthroughs in physics,chemistry,biology,and *** frequency combs pushed measurement limits with ultrahigh-frequency accuracy and fast-measurement speed,while tunable-diode-laser spectroscopy is used in scenarios that require high power and continuous spectral *** these advantages of tunable-diode-laser spectroscopy,it is challenging to precisely determine the instantaneous laser frequency because of fluctuations in the scan ***,we demonstrate a simple spectroscopy scheme with a frequencymodulated diode laser that references the laser on-the-fly to a fiber *** fiber cavity's free spectral range is on-the-fly calibrated with sub-10-Hz frequency *** achieve a relative precision of the laser frequency of 2×10^(-8)for an 11-THz frequency range at a measurement speed of 1 THz∕*** is an improvement of more than 2 orders of magnitude compared to existing diode-laser-spectroscopy *** scheme provides precise frequency calibration markers,while simultaneously tracking the instantaneous scan speed of the *** demonstrate the versatility of our method through various applications,including dispersion measurement of a fiber,ultrahigh-Q microresonators,and spectroscopy of a hydrogen fluoride gas *** simplicity,robustness,and low cost of this spectroscopy scheme are valuable for out-of-the-lab applications like lidar and environmental monitoring.

关键词： tunable laser spectroscopy radio-frequency modulation integrated photonics gas spectroscopy frequency comb

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TRADE DEPENDENCIES AND TRANSACTION COSTS: THE OC-CUPATION OF DECELEA HIGHLIGHTS BOTH THE BENEFITS AND THE DRAWBACKS OF A MARITIME ECONOMY

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Journal of Ancient Civilizations 2024年第1期39卷 29-50,123页

作者： pascal Warnking Trier University and LEIZA

Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the *** calls into question the well-established consensus that sea transport was far cheaper than land *** paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally *** this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.

关键词： convoy Decelea maritime dependencies maritime economy sea routes shipping costs transaction costs

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An inverse method for characterization of dynamic response of 2D structures under stochastic conditions

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Chinese Journal of Aeronautics 2024年第3期37卷 440-455页

作者： Xuefeng LI Abdelmalek ZINE Mohamed ICHCHOU Noureddine BOUHADDI pascal FOSSAT Laboratory of Tribology and Systems Dynamic Central School of LyonEcully 69134France Institut Camille Jordan Central School of LyonEcully 69134France Department of Applied Mechanics University of Burgundy Franche-ComtéBesancon 25000France

The reliable estimation of the wavenumber space(k-space)of the plates remains a longterm concern for acoustic modeling and structural dynamic behavior *** current analyses of wavenumber identification methods are based on the deterministic *** this end,an inverse method is proposed for identifying wave propagation characteristics of twodimensional structures under stochastic conditions,such as wavenumber space,dispersion curves,and band *** proposed method is developed based on an algebraic identification scheme in the polar coordinate system framework,thus named Algebraic K-Space Identification(AKSI)***,a model order estimation strategy and a wavenumber filter are proposed to ensure that AKSI is successfully *** main benefit of AKSI is that it is a reliable and fast method under four stochastic conditions:(A)High level of signal noise;(B)Small perturbation caused by uncertainties in measurement points’coordinates;(C)Non-periodic sampling;(D)Unknown structural *** validate the proposed method,we numerically benchmark AKSI and three other inverse methods to extract dispersion curves on three plates under stochastic *** experiment is then performed on an isotropic steel *** investigations demonstrate that AKSI is a good in-situ k-space estimator under stochastic conditions.

关键词： Inverse method Dispersion relation Wavenumber space Periodic plates Stochastic conditions Wave propagation characterization

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Modelling of the variation of granular base materials resilient modulus with material characteristics and humidity conditions

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Journal of Road Engineering 2024年第1期4卷 27-35页

作者： Jean-pascal Bilodeau Erdrick Leandro Perez-Gonzalez Ali Saeidi Departement de Genie Civil et Genie des Eaux Universite LavalQuebecG1V 0A6Canada Departement des Sciences Appliquees Universite du Quebeca ChicoutimiChicoutimiG7H 2B1Canada

This study aims to quantify the susceptibility of granular materials used in pavements to changes in moisture content and propose a correlation model to incorporate this susceptibility into seasonal *** fines content and the percentage of fractured coarse aggregates were identified as direct indicators of the resilient modulus susceptibility to changes in water *** results showed that the percentage of fractured coarse aggregates particles(FR)has a more significant impact on the resilient modulus(Er)of crushed granular materials used in pavement construction than the combined indicator of the fines content and sample volumetrics(nf).Crushed granular materials with a higher percentage of fractured coarse aggregates are relatively insensitive to changes in the degree of saturation,but become more sensitive as the fine fraction porosity *** adjusted model was proposed based on the existing formulation,but considers a complex parameter to describe and adjust the sensitivity of base granular materials to variations in moisture content with respect to fabrication charac-teristics,fines content and volumetric *** model shows that the variation of Er values is below10%for fully crushed granular ***,it reaches approximately±12%for materials with 75%of crushed coarse aggregates andþ40%and-25%for materials with FR=50%.This model could help select good ag-gregates characteristics and adjust grain-size distribution for environments where significant moisture content variations can occur in the pavement system,such as in the Province of Quebec(Canada).As it is based on pa-rameters that can be easily determined or estimated,it also represents a valuable tool for detailed design and analysis that can consider material characteristics.

关键词： Resilient modulus Degree of saturation Humidity conditions Unbound granular materials Pavement base

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Defense and senescence interplay in legume nodules

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Plant Communications 2024年第4期5卷 112-126页

作者： Fathi Berrabah Farouk Benaceur Chaoyan Yin Dawei Xin Ke´vin Magne Marie Garmier Veronique Gruber pascal Ratet Faculty of Sciences University Amar Telidji03000 LaghouatAlgeria Research Unit of Medicinal Plants(RUMP) National Center of Biotechnology ResearchCRBt25000 ConstantineAlgeria Universite´Paris-Saclay CNRSINRAEUniversity of EvryInstitute of Plant Sciences Paris-Saclay(IPS2)91190 Gif-sur-YvetteFrance Universite´Paris Cite´ Institute of Plant Sciences Paris-Saclay(IPS2)91190 Gif-sur-YvetteFrance Key Laboratory of Soybean Biology in the Chinese Ministry of Education College of AgricultureNortheast Agricultural UniversityHarbin 150030China These authors contributed equally to this article.

Immunity and senescence play a crucial role in the functioning of the legume symbiotic *** miss-regulation of one of these processes compromises the symbiosis leading to death of the endosymbiont and the arrest of the nodule *** relationship between immunity and senescence has been exten-sively studied in plant organs where a synergistic response can be ***,the interplay be-tween immunity and senescence in the symbiotic organ is poorly discussed in the literature and these phe-nomena are often mixed *** studies revealed that the cooperation between immunity and senescence is not always observed in the nodule,suggesting complex interactions between these two pro-cesses within the symbiotic ***,we discuss recent results on the interplay between immunity and senescence in the nodule and the specificities of this relationship during legume-rhizobium symbiosis.

关键词： immunity senescence symbiosis nodules legumes rhizobia

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