University of Ngaoundéré

Activated Carbon derived from the bones of Bos Indicus Gudali (ACB) is introduced in this study as a novel and environmentally friendly option for the adsorption of Crystal Violet dye (CV) from water. Various characterization techniques, including semiquantitative X-ray analysis, X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (ATR–FTIR), and Point of Zero Charge (pHPZC), were employed to analyze the bone pyrolysis process. The study investigated how various factors such as the mass of the adsorbent, the initial pH of the solution, contact time, initial dye concentration, and temperature influence the batch adsorption process. Kinetic data were examined using several models including Intra-particle diffusion, Elovich, Pseudo-first-order, and Pseudo-second-order. The findings indicated that the Pseudo-second-order model accurately captured the kinetics of CV adsorption onto ACB. For the isothermal data analysis, the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models were employed. The equilibrium data for CV adsorption onto ACB fit the Langmuir isotherm model most effectively, revealing a maximum adsorption capacity of 17.331 mg g−1 at 303 K. Moreover, the Dubinin-Radushkevich model suggested that the nature of the adsorption was physical. The thermodynamic analysis confirmed that the adsorption process was physical, spontaneous, and exothermic.

In Africa, pig significantly contributes to animal protein supply to enhance food security. Pig farming in Cameroon is subject to perpetual health threats, with the spread of several diseases which strongly impact the production. This study aimed to evaluate the biosecurity compliance in pig farms in the West Region of Cameroon and assess its relationship with production performance. During on farm visit and face to face interview, data about biosecurity, veterinary drug usage and production parameters were collected in 78 randomly selected farms from April and October 2024. Results showed that almost all of pig farms (98.7%) used antiparasitics and 94.9% used antibiotics for preventive (58.7%) or curative (41.3%) purposes. Vaccination against swine erysipelas was practiced by only 24.4% of farmers. More than half of the farms (64.1%) in the study area had a biosecurity score below 50 out of 100 and the average biosecurity score was 47 (ranged 28-66). Biosecurity measure related to personnel and visitors ranked the lowest score (21, range 0-71) while measures applied during farrowing and suckling period (77, range 20-100), and those associated with the environment and region (77, range 40-100) ranked the highest. The biosecurity level was significantly influenced by the years of experience and the training in pig farming of interviewees, the herd size, the type of breeds reared and the production type (farrower, grower‐finisher or farrow‐to‐finish). Findings revealed a moderate association between number of farrowings per sow per year and lactation length. A correlation was found between biosecurity and lactation length. The high mortality rate (44.64 ± 24.60%) recorded on farms with a poor level of biosecurity compared to others (15.45 ± 11.94%) shows the importance of biosecurity in the prevention and control of diseases and the improvement of production. The results of this study highlight the need for capacity building and awareness among farmers on the importance of implementing biosecurity measures for improving pig production.

Azadirachta indica leaves, commonly known as neem leaves, and Carica papaya leaves, commonly known as pawpaw leaves, are both rich in active compounds with potential insecticidal and fungicidal abilities. The objective of this work was to formulate a biocide for wood control. Extractions were done by simple maceration of neem and papaya leaf powder using ethanol/distilled water (80:20). Phytochemical screening was then carried out to determine the chemical composition of the leaf extracts. Determination of total polyphenol content was done using the Folin-Ciocalteu method. A mixture design was used to optimize the biocide formulation. Antifungal and insecticidal activities were evaluated using the pit method and the mass-loss method, respectively. The results show that extractions of neem and papaya leaf powder yielded 77.78% and 57.71%, respectively. Their total polyphenol contents were 27.5±1.3 and 17.3±0.9 mg EAG/g powder, respectively. The amylose content of corn starch was 29.45±0.38%, which conferred a sticky property. Optimization of the biocide formulation yielded the following optimal composition: 10% extracts, 10% corn starch glue, and 80% water. Evaluation of antifungal activity showed that Mucor sp. was more sensitive than Rhyzopus sp. to the formulated biocide, with inhibition diameters of 10 and 8 mm, respectively. Evaluation of insecticidal activity with doses of 15 ml and 20 ml per 200 g of wood did not result in any weight loss. Therefore, the formulated biocide could thus constitute a green, non-toxic alternative to conventional chemical products for wood termite control.

Aim: The political landscape of Cameroon has been dominated for decades by men in most decision-making instances. These gender differences are a result of obnoxious practices linked to the traditional influence of patriarchy and various barriers at different levels, such as low self-esteem of some women, policymaking and legal framework in favor of gender equality. This study examines the empowerment of women in Cameroon’s political leadership in elected positions and high-level governance roles in order to address gender inequality. Methods: This study employs qualitative analysis from empirical data and official reports to examine initiatives and policies supporting women’s political empowerment in Cameroon. Results: The results of our findings indicate a gradual cultural shift favorable to women’s political participation, alongside government gender-sensitive policies, capacity-building programs, and efforts to enhance the education and economic opportunities of women. Conclusion: Though a gradual progress has been made in empowering women politically, sustained efforts are needed to overcome remaining social and institutional barriers. Recommendation: The study recommends continued reforms, public awareness campaigns, and targeted capacity-building programs to further promote gender equality in political leadership.

In response to the growing environmental challenges associated with plastic waste management, the production of alternative fuels through pyrolysis emerges as a promising solution. This study evaluates the conversion of low-density polyethylene (LDPE) and polystyrene (PS) into liquid fuels using two pyrolysis systems equipped with a coaxial condenser (unit 1) and a tubular condenser (unit 2), respectively. The main objective is to compare their performance in terms of oil yield and the quality of the resulting products. The results indicate that the system equipped with a tubular condenser delivers better performance in terms of yield. Specifically, the pyrolysis of 1000 g of LDPE resulted in oil yields ranging from 76.2% to 79.4% ± 2.2 for units 1 and 2, respectively. In comparison, PS pyrolysis produced lower yields of 65.7% and 64.9% ± 0.5 for the same units. Physicochemical analysis of pyrolysis oils revealed properties similar to those of commercial diesel fuel. These oils have several characteristics that comply with Cameroonian standards, European standard EN 590, and ASTM standard D7544, particularly with regard to sulfur content, acid number, gross calorific value, cetane number, cloud point, and pour point. In fact, for oil produced by LDPE pyrolysis in Unit 2, the higher heating value (HHV) was 55.3 MJ/kg (compared to 42-45 MJ/kg for EN 590) and the cetane number was 52.4 (compared to >46 for EN 590). However, certain parameters did not meet industry standards, notably the flash point at 37.0°C (compared to >55°C for EN 590) and the viscosity at 1.101 mm²/s (compared to 2.0-4.5 mm²/s). These non-conformities are the main reason why fractional distillation is proposed to refine the products. This study makes a significant contribution to the development of pyrolysis systems tailored for plastic waste recovery, offering practical insights for large-scale implementation and reinforcing the potential of alternative fuels in the energy transition.

The Mora Commune in the Far North of Cameroon, specifically within the Mayo-Sava department, has faced a significant influx of migrants since 2013 due to renewed threats from the Boko Haram terrorist sect. This migration includes individuals from Nigeria, Chad, the Central African Republic, and internally displaced persons from villages near the Nigerian border, heightening demographic pressure in the commune. This continuous arrival of migrants has impacted agricultural land use, sparking conflicts between the settled migrant population outside camps and the local host community. The study seeks to characterise these agricultural land-use conflicts, identify their determinants, and propose mitigation strategies. This analysis relies on the theory of osmosis and a methodology that integrates quantitative and qualitative approaches, employing tools such as documentary research, observation, questionnaires, and interviews conducted in three villages: Igawa, Massaré II, and Waladé. Key findings reveal a marked increase in both refugees outside camps (12,269 in 2015, 11,706 in 2016, and 40,458 in 2020) and internally displaced persons (64,266 in 2015, 65,606 in 2016, and 255,886 in 2020), leading to a diversification of agricultural land users. This surge has intensified land pressure, resulting in significant consequences: a fluctuating reduction in cultivated agricultural spaces by approximately 10% between 2000 and 2020, the abandonment of numerous fields (10,925.62 ha in 2014; 13,184.36 ha in 2015; and 18,351.85 ha in 2016) due to insecurity, and a subsequent decline in major crop production. Conflicts have also arisen from mixed land acquisition methods and strained social cohabitation. State interventions, including sanctions and victim compensation, have been implemented, but further conflict reduction could involve community awareness campaigns to discourage self-justice and the formalisation of land ownership through location and purchase certificates. Additionally, the adoption of market gardening systems by migrants for certain food crops has begun to mitigate agricultural losses and alleviate tensions over land use.

Bacterial pneumonia involves acute lung parenchyma and alveolar inflammation triggered by various bacteria, leading to fever, cough, dyspnea, and potential complications like sepsis or respiratory failure. The treatment of this infection is increasingly hindered by antibiotic resistance, thus justifying the pressing need to search for effective treatments against bacterial pneumonia. This study aims to evaluate the antimicrobial activity of Gnetum africanum (G. africanum) and Callistemon rigidus (C. rigidus) extracts on selected pneumonia-causing bacteria. Extracts from the bark and flowers of C. rigidus and from the leaves of G. africanum, were obtained by successive maceration using solvents of increasing polarity, including hexane, dichloromethane, ethyl acetate, methanol and water. The inhibitory effects of the as-prepared extracts (20) were assayed against five pneumonia-causing bacteria, including Staphylococcus aureus (two strains), Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii. The bacterial (S. aureus HM-468) growth kinetics were evaluated with the most active extract (CrMeOHE, methanol extract of C. rigidus bark). The yields of plant extraction ranged from 0.507 to 18.12 %. The CrMeOHE extract was the most active extract with minimum inhibitory concentrations (MICs) of 62.5, 125 and 500 µg/mL on S. aureus NR-46003, S. aureus HM-468 and A. baumannii NR-17784, respectively. The hexane extract of G. africanum inhibited the growth of S. aureus HM-468 with MIC value of 500 µg/mL. The time-kill kinetics of CrMeOHE extract on S. aureus HM-468 revealed a bactericidal effect at MIC, 2 MIC and 4 MIC. These results suggest that extracts of G. africanum and C. rigidus possess antibacterial activity and could serve as starting points for the discovery of drugs against pneumonia.

<title>Abstract</title> The Laddé-Goré granitoids, located in the northern Pan-African Belt of Cameroon, comprise a compositionally and mineralogically diverse suite of plutonic rocks that offers key insights into the magmatic and tectonic evolution of Central Africa during the Neoproterozoic. This study integrates petrographic observations with major and trace element geochemistry, as well as REE patterns, to decipher their petrogenesis and geodynamic setting. The suite includes amphibole-bearing granites, amphibole-biotite-muscovite granites, muscovite leucogranites, and quartz diorites. Whole-rock analyses show SiO2 contents ranging from 63.9 to 71.2 wt%, with high K2O + Na2O (7.2–8.6 wt%) and metaluminous to weakly peraluminous signatures (A/CNK = 0.97–1.04). The rocks display magnesian affinities, and high-K calc-alkaline to shoshonitic trends. Trace element data reveal high contents of LILEs (Rb = 45–147 ppm, Ba = 1090–2458 ppm), moderate REE enrichment (La = 20.8–168 ppm, Ce = 34.2–346 ppm), and negative anomalies in Nb, Ta, Ti, and P, suggesting derivation from a subduction-modified source. Eu anomalies (Eu/Eu* = 0.36–1.85) and fractionation indices (La/Yb)N = 19.4–41.1; (Gd/Lu)N = 2.1–4.4) imply variable degrees of plagioclase and amphibole fractionation. Geochemical modeling supports magma generation from a metasomatized lithospheric mantle, followed by fractional crystallization and limited crustal assimilation. The granitoids evolved in a transitional setting between an active continental margin and early post-collisional extension. Comparative data from Pan-African suites in Nigeria, Sudan, and northeastern Brazil further confirm that Laddé-Goré magmatism is part of a broader crust–mantle interaction regime during the final stages of Gondwana assembly. The associated enrichments in Sn (Nb = 12-32ppm; Ta = 0.5-1.3ppm; W = 0.5ppm) suggest potential for specialized mineralization.