Cercocebus lunulatus, an endangered primate species, is endemic to three countries in West Africa, including Côte d’Ivoire. In this country, remnant populations of this species have survived in four protected areas including Comoé National Park, which is considered to harbor the largest wild population. However, the park faces significant anthropogenic pressures, including poaching, mining, and agricultural activities in peripheral areas, which hinder sustainable management and conservation efforts. For two decades, updated information on this species’ population size, group structure and food availability has been almost non-existent due to non-focused studies. From November 2021 to November 2022, we collected data using camera traps and phenological data in the park’s forest habitats. A total of 25 groups of white-naped mangabeys, estimated at about 1396 individuals, were recorded with seasonal variations in group size comprising 10 to 249 and 10 to 192 individuals in dry and rainy seasons, respectively. The mean density is 25.38 individuals /km². Groups comprise 44
The Pengshui area, recognized for its normal pressure shale gas reservoirs, exhibits complex fluid migration behaviors due to a high proportion of small-pore porosity and significant microscale effects. These factors result in distinctive production characteristics, such as longer dewatering cycles, higher flowback rates, and reduced well production capacity, compared with overpressured shale gas reservoirs. In this study, we explore the migration and retention behaviors of fracturing fluid concerning lithofacies and pore structure differences, emphasizing the flowback process following fracturing. Laboratory simulation experiments were performed on 12 Longmaxi shale samples from the PY-1 well, categorized by petrographic phases, total organic carbon (TOC) content, and mineral composition. Pore structures were examined using various methods, including X-ray diffraction, field-emission scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), low-temperature nitrogen adsorption, and high-pressure mercury injection. The results indicated that the shale samples from the PY-1 well could be divided into two lithofacies-clay-rich siliceous shale and mixed-siliceous shale. The clay-rich siliceous shale displayed narrow fissure porosity, while the mixed-siliceous shale featured organic micropores and microcracks. Pore structure characterization revealed that the clay-rich siliceous shale developed a "tree-like" mesopore network, facilitating fluid migration, while the mixed-siliceous shale had a "micropore-microcrack" network that promotes fluid retention. The permeability and porosity of these samples were classified as medium, with high permeability attributed to the extensive fractures in the PY-1 well. Simulating the flowback process, we demonstrate that fracturing fluid was distributed across the entire pore size range due to capillary pressure differences, with pressure transmission generating new fractures at proximal fracture faces and enhancing connectivity. Micropores, particularly in mixed-siliceous shale, adsorbed water and competed with methane for adsorption. The findings also indicated that the pore structures in clay-rich siliceous shale were more sensitive to pressure changes, making them susceptible to Jamin's effect, whereas mixed-siliceous shale, with its lower connectivity, showed less variation in water content under pressure fluctuations but exhibited greater adsorption capacities. This study offers insights into the role of lithofacies and pore structure in the migration and retention behaviors of fracturing fluid.
Cordyla pinnata is a multipurpose forage species that plays important ecological and socio-economic roles in sub-Saharan Africa. We investigated how different land use types affect the species' population structure and distribution in Senegal. Forest inventories were conducted in 140 plots across four land use types: farmland, fallow, rangeland, and protected area. Diameter at breast height (dbh), crown diameter, height, and regeneration of C. pinnata were measured, and woody species composition was noted. The results showed significant differences in species composition across land use types, with protected areas and rangelands showing the highest species diversity. The density of mature C. pinnata trees was highest in protected areas (393.63 +/- 24.21 stems/ha) and lowest in farmlands (140.40 +/- 46.70 stems/ha), suggesting that agricultural expansion has a strong negative impact on the species. Diameter class distributions suggested a stable population structure of mature trees, whereas regeneration patterns revealed an unstable state, raising concerns about the species' future sustainability. Our findings underscore the adverse effects of land use changes on C. pinnata and highlight the need to mitigate human pressure on ecosystems to ensure conservation of this valuable species and the biodiversity it supports. Cordyla pinnata est une esp & egrave;ce fourrag & egrave;re polyvalente d'importance & eacute;cologique et socio-& eacute;conomique & eacute;lev & eacute;e en Afrique subsaharienne. Nous avons & eacute;valu & eacute; l'effet de diff & eacute;rents types d'utilisation du sol sur la structure des populations et la r & eacute;partition spatiale de l'esp & egrave;ce au S & eacute;n & eacute;gal. Des inventaires ont & eacute;t & eacute; r & eacute;alis & eacute;s dans 140 placettes au sein de quatre cat & eacute;gories d'utilisation des terres : champs cultiv & eacute;s, jach & egrave;res, p & acirc;turages et aires prot & eacute;g & eacute;es. Le diam & egrave;tre & agrave; hauteur de poitrine (DHP), le diam & egrave;tre de la cime, la hauteur, ainsi que la r & eacute;g & eacute;n & eacute;ration ont & eacute;t & eacute; mesur & eacute;s. La composition sp & eacute;cifique d'esp & egrave;ces ligneuses a aussi & eacute;t & eacute; not & eacute;e. Les r & eacute;sultats r & eacute;v & egrave;lent des diff & eacute;rences significatives de composition sp & eacute;cifique entre les milieux, les aires prot & eacute;g & eacute;es et les p & acirc;turages pr & eacute;sentant les niveaux de diversit & eacute; sp & eacute;cifique les plus & eacute;lev & eacute;s. La densit & eacute; des arbres matures de C. pinnata & eacute;tait plus & eacute;lev & eacute;e dans les aires prot & eacute;g & eacute;es (393,63 +/- 24,21 tiges/ha) que dans les champs cultiv & eacute;s (140,40 +/- 46,70 tiges/ha), indiquant que l'expansion agricole constitue une pression n & eacute;gative importante sur l'esp & egrave;ce. La distribution des classes de diam & egrave;tre met en & eacute;vidence une structure adulte globalement stable, tandis que les tendances observ & eacute;es pour la r & eacute;g & eacute;n & eacute;ration t & eacute;moignent d'un & eacute;tat instable semant le doute quant & agrave; la durabilit & eacute; des populations. Nos observations soulignent les effets n & eacute;gatifs des changements d'utilisation des terres sur C. pinnata et la n & eacute;cessit & eacute; de limiter les impacts anthropiques sur les & eacute;cosyst & egrave;mes de mani & egrave;re & agrave; assurer la conservation de cette esp & egrave;ce d'int & eacute;r & ecirc;t et la biodiversit & eacute; qu'elle soutient.
2-Aminobenzothiazole (aBTH) and para-toluene sulphonamide (pTSA) are classified as high-production-volume, toxic and persistent emerging pollutants originating from industrial and agricultural activities. As a result, their presence in aquatic environments poses environmental and health risks, making it necessary to develop effective methods for their removal, such as trapping them in absorbent materials. In this study, two pollutants (aBTH and pTSA) on two clay mineral surfaces, namely kaolinite and magnesium-substituted montmorillonite bearing Ca2+ compensating cations at the surface, were investigated. Using density functional theory (DFT), Car–Parrinello molecular dynamics simulations were employed to explore the potential energy surfaces, followed by static calculations to obtain energetic properties. The results indicate that, on kaolinite, the adsorption of both aBTH and pTSA occurs predominantly through the formation of hydrogen bonds. In contrast, on montmorillonite, the adsorption is dominated by electrostatic interactions with Ca2+ cations, which play a key role in the stability of the formed complexes. The calculated adsorption energies indicate that aBTH and pTSA bind more strongly to montmorillonite than to kaolinite. For the most stable studied complexes, Mont–aBTH (1oD) and Mont–pTSA (1p), the values reach −36.3 and −37.7 kcal mol−1, respectively, while on kaolinite, they rise to −24.9 kcal mol−1 for kao–aBTH (1pD) and −27.1 kcal mol−1 for kao–pTSA (1p). The stronger adsorption energies on Mont originate from the interaction between one heteroatom of the pollutants (cycle N or O) and one compensating Ca2+ cation present on the clay surface. Moreover, adsorption of a pollutant at a clay surface causes local structural rearrangements at interacting sites with a larger impact on kaolinite (Hb) than on montmorillonite (Ob and Ca2+ cations). The results also provide important information such as the preferred pollutant orientation on the surface. Furthermore, this study highlights the decisive role of compensating ions in the adsorption, suggesting that calcium-rich montmorillonite is a particularly efficient mineral for trapping these contaminants.
Résumé : La pièce théâtrale Historia de una escalera (1949) d’Antonio Buero Vallejo permet d’observer, par le jeu des personnages masculins, l’impossibilité pour ceux-ci de se réaliser. Le dramaturge pointe du doigt l’inaction des hommes qui, au lieu de lutter pour changer leur condition sociale sous le franquisme, agissent plutôt de manière contre-productive. Le jeu dramaturgique de l’écrivain espagnol est élaboré en vue de dénoncer les attitudes et comportements des hommes qui s’enferment dans une passivité plongeant la société dans l’immobilisme. Mots-clés : théâtre, Buero Vallejo, dramaturge, personnage masculin, franquisme
