University of Ghardaia

This study analyzes the issue of political reform in the Arab Gulf states amid accelerated regional and international transformations, particularly following the Arab Spring and the ensuing internal and external pressures on regional political systems. It proceeds from the hypothesis that political stagnation and the absence of effective popular participation constitute one of the primary causes of internal crises, placing regimes before challenges related to legitimacy, stability, and responsiveness to citizens' demands. The study discusses the evolution of the concept of political reform—from being perceived as a tool of foreign intervention or international conspiracy to an urgent internal necessity imposed by shifts in the international environment and its conflicts, including proxy wars. It highlights the specificity of Gulf governance systems, which rely on traditional loyalties, while raising questions about these regimes' capacity to adapt to current transformations. The study concludes by forecasting two main scenarios for the region's future: either the resilience of regimes through genuine gradual reforms, or entry into paths of disintegration should the trust gap between rulers and ruled persist.

The rhizosphere, a confined area of soil plant roots, is an intersection of microbial activity and root exudates. Known as the rhizosphere effect, it enhances crop yield and sustainability by improving nutrient availability, beneficial compounds, and pathogen control. This study combines a field-based rhizosphere–bulk soil comparison for peanut with a geostatistical approach to quantify the spatial variability of rhizosphere-driven changes in soil quality indicators in the Ghardaïa region (southern Algeria), which is known for its sandy–clay and sandy–loam soils. Samples of rhizosphere and bulk soils were prospected using a systematic plan. Subsequently, the pH, electrical conductivity, calcium carbonate, organic matter, total nitrogen, available phosphorus, total potassium, and soluble sodium were determined for each soil (rhizosphere and bulk soil). To assess the spatial variability of rhizosphere soil parameters, semi-variograms of the fitted models were generated using auto-kriging. The results showed that both types of soils were moderately alkaline, with a reduction of 5.52% in the pH of the rhizosphere compared to the bulk soils. Soils were relatively low in organic matter, with only 3.3% of soils having organic matter levels above 20 g kg−1. However, organic matter contents were consistently higher in the rhizosphere (8.51 ± 4.59 g kg−1) than in the bulk soil (6.78 ± 3.52 g kg−1). In the rhizosphere, an increase of 10% in labile phosphorus was noted. Total nitrogen was increased by 52.57%. T-tests suggested no significant difference in potassium and sodium levels, and they were moderately present in both soils. Significantly positive relationships were noted between available phosphorus and total nitrogen (R = 0.59, p < 0.001). However, negative correlations were revealed between pH and organic matter available phosphorus (R = −0.77, p < 0.001) and pH and total nitrogen (R = −0.56, p < 0.01). These results indicate the effects of rhizosphere interactions on soil property improvements and their implications for sustainable agricultural practices, including crop rotation, intercropping, and green manure applications.

Seonamhaeicola marinus, a marine bacterium from the family Flavobacteriaceae, was genomically analyzed. Approximately 23% of its predicted CDSs were linked to subsystems, with amino acid and protein metabolism being the most abundant. Four biosynthetic gene clusters (BGCs) were identified, including those for flexirubin and carotenoid. CAZyme analysis via dbCAN3 revealed 178 CAZymes, representing 3.87% of the genome, with glycosyl hydrolases, particularly GH2, being the most prevalent group. Polysaccharide-producing organisms, such as those yielding carrageenan from red algae, find applications in food, cosmetics, and pharmacology. ι-Carrageenan, characterized by its double sulfate groups, holds significant potential in pharmaceutical systems. ι-Carrageenase A2 from S. marinus has desirable properties for carrageenan processing, supporting the investigation of such novel enzymes for biotechnological uses. This study aimed to comprehensively analyze S. marinus ι-carrageenase A2 through various computational modeling methods. A comparative analysis of the enzyme’s physicochemical properties, binding site locations, and structural features was conducted with other enzymes from the same family. Multiple computer modeling software programs were employed for three-dimensional structure prediction and modeling. Molecular docking identified potential ligands, with neo-ι-carratetraose demonstrating strong binding affinity. Molecular dynamics simulations assessed the stability and flexibility of the ligand-enzyme complex, offering insights into key residues involved in substrate interactions.

Salinisphaera is a genus of moderately halophilic bacteria within the class Gammaproteobacteria, commonly isolated from diverse saline environments. Traditional phenotypic methods have proven insufficient to resolve taxonomic boundaries among closely related species in this genus. With the advent of whole-genome sequencing, genome-based analyses have become essential for accurate species and subspecies delineation. This study used comprehensive phenotypic and genomic comparisons to investigate the taxonomic relationship between Salinisphaera halophila YIM 95161T and Salinisphaera orenii MK-B5T. Phylogenomic analyses based on core gene alignments revealed that S. halophila YIM 95161T and S. orenii MK-B5T form a robust monophyletic clade, consistent with high average nucleotide identity (>96%) and digital DNA-DNA hybridization values (>70%), confirming their membership within the same species. However, notable and consistent differences in growth physiology, enzymatic activity, fatty acid composition and genomic G+C content (69.5 mol% vs. 63.4-63.6 mol%) support the recognition of two distinct subspecies. Carbohydrate-active enzyme (CAZyme) repertoires also revealed divergence in CAZyme profiles, aligning with ecological differentiation. Therefore, we propose that S. halophila YIM 95161T be reclassified as S. orenii subsp. halophila subsp. nov., while S. orenii MK-B5ᵀ be retained as S. orenii subsp. orenii subsp. nov. This refined classification highlights the value of integrated genomic and phenotypic approaches in resolving intraspecific structure and improving taxonomic resolution within halophilic bacterial genera.

In arid regions, the soil degradation from salinization, low organic matter content, and compaction severely limits agricultural productivity. Leguminous perennials such as alfalfa (Medicago sativa L.) have the potential to restore soil quality, but their long-term effects remain underexplored in North African drylands. This study aimed to evaluate the impacts of long-term (7–8 years) alfalfa cultivation on soil fertility and salinity in the Ziban region of Algeria. Ninety topsoil samples (0–30 cm) from cultivated and adjacent uncultivated plots were collected and analyzed, determining organic matter (OM), soil organic carbon (SOC), soil nitrogen stock (SNS), electrical conductivity (EC), sodium adsorption ratio (SAR), pH, major cations (Ca2+, Mg2+, Na+), sulfate (SO42−), bulk density (BD), and texture. Compared with uncultivated soils, alfalfa cultivation increased OM by 82.26%, SOC by 78.38%, and SNS by 102.99%, while reducing EC by 40.36%, SAR by 28.94% and BD by 6.16% (p < 0.05), indicating significant improvements in fertility, structure and reductions in sodicity. PCA revealed distinct gradients separating fertility–salinity parameters from compaction–sodicity in cultivated and uncultivated soils. These results confirm that alfalfa systems enhance nutrient cycling, reduce salt stress, and improve structural stability in arid agroecosystems through reduced bulk density and increased organic matter in arid agroecosystems. Integrating alfalfa into land management strategies could promote sustainable restoration of degraded soils in drylands. Further research should optimize irrigation and organic inputs to maximize these benefits under climate-stress conditions.

Contexte : Le dromadaire (Camelus dromedarius) suscite un intérêt croissant dans le secteur agricole algérien, en raison de ses capacités à fournir une large variété de biens et de services dans des environnements contraignants comme le Sahara, contribuant ainsi au développement de filières d’élevage durables. Objectif : La présente étude visait à analyser le système d’élevage camelin laitier intensif dans la région de Ghardaïa (Sahara septentrional algérien) afin d’évaluer les voies de développement possible à l’échelle locale. Méthodes : Huit exploitations et 77 chamelles (soit 73 % des exploitations et 61 % du total des chamelles inscrites dans la filière lait de la région) ont été suivies. Une analyse en composantes principales (ACP) a permis d’établir une typologie des chamelles selon leur conduite et de leurs performances zootechniques. Résultats : Trois types de chamelles ont été identifiés, principalement caractérisés par un effet « ferme » très important sur les performances individuelles (âge à la première saillie et à la première mise bas, intervalle entre mises bas, production journalière du lait, durée de lactation, durée de tarissement et recouvrement lactation gestation). La variabilité génétique des animaux était intéressante surtout pour la productivité laitière. L’étude des relations entre conduite du troupeau et performances individuelles a montré que le polyélevage s’accompagnait de performances de reproduction plus tardives, alors que l’acquisition des terres n’était pas un moyen pour diminuer les quantités d’aliments achetés. Le poids des chamelles influait sur l’âge au premier chamelage, et présentait une corrélation négative avec l’intervalle inter-chamelage. Deux des types de fermes, composant la moitié des fermes, ayant des rapports élevés en PDI/UFL (au-delà de 81 g) présentaient une diminution de l’âge à la première mise bas et de l’intervalle entre chamelages. Les rations excessivement concentrées tendaient à prolonger la lactation après la fécondation des chamelles. La stimulation de la lactation a permis des recouvrements lactation-gestation plus longues (5,44 mois), un effet qui demeure relatif à la durée de l’intervalle entre mises bas. La forte incorporation des aliments concentrés dans la ration et le gaspillage nutritif diminuaient la productivité laitière. Conclusions : La diversité des systèmes d’élevages camelins est un élément nécessaire de leur souplesse face aux aléas climatiques, économiques et techniques, contribuant à leur résilience.

The Perovskite solar cells (PSCs) have surpassed 26% laboratory efficiencies, making them promising for nextgeneration photovoltaic (PV) technologies. However, their commercial adoptions remain challenged by rapid degradation under fluctuating environmental conditions. While conventional drift-diffusion models focus on steady-state conditions, they do not capture the dynamic interplay between temperaturehumidity cycle and material degradation mechanisms that dictate long-term device stability. This paper introduces a novel, compact MATLAB-based drift-diffusion framework that incorporates daily cyclic environmental profiles and updates material parameters over time to simulate outdoor operating conditions realistically. The model integrates Poisson's and modified continuity equations, allowing key material properties such as carrier mobility, lifetime, and trap density, to dynamically respond to sinusoidal changes in temperature <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\left (\pm 10^{\circ} \mathrm{C}\right)$</tex> and relative humidity (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 20 \%$</tex>), representative of natural diurnal cycles. Full validation against recent literature shows excellent agreement with simulated current-voltage (I-V) characteristics, spatial carrier distributions, and thermal responses matching experimental triple-cation PSCs data within 5%. By optimizing absorber thickness under environmental stress, the framework uncovers design rules that improve power conversion efficiency (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P C E$</tex>) from 18.9 % to 20.2 % while enhancing longevity. The optimum thickness of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 500 ~\text{nm}$</tex> balances absorption enhancement and recombination loss maintaining performance without degrading stability. This computationally efficient platform provides for researchers and industry practitioners a valuable tool for rapid pre-prototyping and stability screening, accelerating the transition from laboratory discoveries to practical commercial PSC products.