Bibliographies: 'Ion – Cameroon'

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Landeryou, Toby, Muriel Rabone, Fiona Allan, et al. "Genome-wide insights into adaptive hybridisation across the Schistosoma haematobium group in West and Central Africa." PLOS Neglected Tropical Diseases 16, no. 1 (2022): e0010088. http://dx.doi.org/10.1371/journal.pntd.0010088.

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Schistosomiasis remains a public health concern across sub-Saharan Africa; current control programmes rely on accurate mapping and high mass drug administration (MDA) coverage to attempt disease elimination. Inter-species hybridisation can occur between certain species, changing epidemiological dynamics within endemic regions, which has the potential to confound control interventions. The impact of hybridisation on disease dynamics is well illustrated in areas of Cameroon where urogenital schistosomiasis, primarily due to Schistosoma haematobium and hybrid infections, now predominate over intestinal schistosomiasis caused by Schistosoma guineensis. Genetic markers have shown the ability to identify hybrids, however the underlying genomic architecture of divergence and introgression between these species has yet to be established. In this study, restriction site associated DNA sequencing (RADseq) was used on archived adult worms initially identified as; Schistosoma bovis (n = 4), S. haematobium (n = 9), S. guineensis (n = 3) and S. guineensis x S. haematobium hybrids (n = 4) from Mali, Senegal, Niger, São Tomé and Cameroon. Genome-wide evidence supports the existence of S. guineensis and S. haematobium hybrid populations across Cameroon. The hybridisation of S. guineensis x S. haematobium has not been demonstrated on the island of São Tomé, where all samples showed no introgression with S. haematobium. Additionally, all S. haematobium isolates from Nigeria, Mali and Cameroon indicated signatures of genomic introgression from S. bovis. Adaptive loci across the S. haematobium group showed that voltage-gated calcium ion channels (Cav) could play a key role in the ability to increase the survivability of species, particularly in host systems. Where admixture has occurred between S. guineensis and S. haematobium, the excess introgressive influx of tegumental (outer helminth body) and antigenic genes from S. haematobium has increased the adaptive response in hybrids, leading to increased hybrid population fitness and viability.

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Kopa Njueya, Adoua, Arnaud Tonang Zebaze, Lucas Kengni, Emile Temgoua, David Guimolaire Nkouathio, and Stéphanie Dannou Chezie. "Assessment of Groundwater Mineralization Processes in Mbakaou Area (Adamawa Plateau – Cameroon), by Using Conventional Diagrams and Multivariate Statistical Analysis." European Journal of Environment and Earth Sciences 2, no. 1 (2021): 44–52. http://dx.doi.org/10.24018/ejgeo.2021.2.1.115.

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Management of groundwater require knowing their qualities and hydrogeochemical processes whereby these waters acquire their mineralization. The population of Mbakaou in Adamawa Plateau consumes groundwater from a doubtful quality water supply structures (wells, boreholes and catchments). This study was carried out to highlight groundwater quality and processes that govern water mineralization. So, to achieve this, 11 water samples were analyzed (1 rain water, 1 well, 3 springs and 6 boreholes). After analyzing the samples and comparing the obtained values to World Health Organization (WHO) standards, multivariate statistical analysis including Principal Component Analysis (PCA) were applied. Results show that these waters samples are fresh, generally of good quality compared to WHO standards and weakly mineralized (35 to 247.9 mg/l), due to the short residence time. Calcium and magnesium bicarbonate facies is the main water type. Nitrates are the most common pollutants and reveal high vulnerability of saprolite aquifer than fractured aquifer. The groundwater mineralization is influenced by precipitation, base ion exchange process, anthropogenic activities and water-rock interaction through silicate weathering. The PCA analysis yielded three factors that explained 89.33 % of the total variance. Factor 1 (62.60 %), factor 2 (15.54 %) and factor 3 (11.19 %) made respectively the difference between water samples influenced by precipitation or water rock interaction from those influenced by both water-rock interaction with precipitation or anthropogenic activities and those for water rock interaction with ion exchange process.

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Talla, Emmanuel, Alfred Ngenge Tamfu, Pierre Biyanzi, et al. "Phytochemical screening, antioxidant activity, total polyphenols and flavonoids content of different extracts of propolis from Tekel (Ngaoundal, Adamawa region, Cameroon)." Journal of Phytopharmacology 3, no. 5 (2014): 321–29. http://dx.doi.org/10.31254/phyto.2014.3504.

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Five extracts of propolis of Adamawa Cameroon were obtained by percolation and maceration with five different solvents: hexane, ethyl acetate, ethanol, methanol and water, in order of increasing polarity. Phytochemical screening was carried out on the extracts and the total content in flavonoids and polyphenols were evaluated by photometric methods. The total flavonoid content was evaluated using the Neu reagent (2-aminodiethyl diphenylborinate) and quercetin as standard and the results varied from 0.84±0.02 gQE/100gRM in ethyl acetate extract to 1.52±0.06 gQE/100gRM in ethanol extract. The total polyphenol content was evaluated using Folin-Ciocalteu reagent and gallic acid as standard and results varied from 2.32±0.37 gGAE/100gRM in the ethyl acetate extract which is the least to 8.64±0.47 gGAE/100gRM in the aqueous extract. The antiradical activities of the extracts were evaluated through their inhibition on DPPH• and IC50 values varied from 1.88 mg/mL in the aqueous extract which showed highest antioxidant power to 5.06 mg/mL in the ethyl acetate extract with the least antioxidant power. BHT and vitamin C were used as synthetic and natural standards respectively and they showed higher antioxidant power compared to the propolis extracts. Ferrous iron chelating capacities of the extracts were determined using potassium ferricyanide reagent and EDTA as standard. Using Stat Graphics software and Durbin-Watson statistics test, the extracts showed significant correlation between flavonoid content and polyphenol content with DPPH• scavenging activity. The ethyl acetate extract showed least ferrous ion chelating capacity while the methanol extract showed highest ferrous ion chelating capacity.

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Lumnwi, Modeste, Wilson Yetoh Fantong, and Samuel Ndonwi Ayonghe. "CHALLENGES OF POTABLE WATER SUPPLY MANAGEMENT IN BAFUT SUB-DIVISION, NORTH WEST REGION OF CAMEROON." International Journal of Research -GRANTHAALAYAH 6, no. 10 (2018): 256–73. http://dx.doi.org/10.29121/granthaalayah.v6.i10.2018.1192.

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Drinking water if not monitored could be a vehicle for diseases of public health concern in Bafut Sub-Division Cameroon. The present study sought to assess the challenges faced by community water supply schemes based on the evaluation of quality and quantity. This study was a cross sectional community survey marked by field survey involving mapping, discharge measurement, potable water samples collection (springs, streams, rain, wells and boreholes) and laboratory analysis. Twelve pipe born water supply schemes and thirty-eight water sources were appraised within two intervals (March-July 2015 and October 2017-March 2018). Chemical analysis was done using an Ion Chromatography and microbial analyses using the presumptive test method and standard plate count. Hospital registers were reviewed on prevalence of water borne diseases. The results showed that major challenges of water supply included; dilapidated pipes, spring inputs and climate variability. Hydro chemical faces were sodium bicarbonate and calcium chloride water types. A total Coliform count of 43 to >1100 per 100ml was recorded for March and July 2015 and 0-236Tcfu in March 2018. Escherichia coli and Salmonella typhi were probably responsible for high rate of water borne diseases. There is need to develop standardize integrated water management plan in this area.

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Dammi Djimi, Estelle Gaëlle, Akebe Luther King Abia, Placide Désiré Belibi Belibi, et al. "Multivariate Statistical and Hydrochemical Analysis of Drinking Water Resources in Northern Cameroon Watersheds." Water 13, no. 21 (2021): 3055. http://dx.doi.org/10.3390/w13213055.

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Watershed pollution by natural and anthropogenic activities remains a global challenge that requires careful and prompt attention. So, identifying possible pollution sources and studying the hydrochemistry of water resources would positively affect human health, especially in resource-limited communities and their economy. Water samples were collected during the rainy season in the North (R-NO) and Adamawa (R-AD) Region communities of Cameroon and assessed for physicochemical parameters using standard methods. The data were analysed using multivariate statistical and hydrochemical methods. Principal component analysis (PCA) retained seven and six principal components explaining 77.65% (R-NO) and 72.24% (R-AD) of the total variance, respectively. The drinking water sources assessed were highly, moderately, and lightly contaminated with turbidity, PO43−, Al3+, Fe2+, Mn2+, NH4+, NO3−, NO2−, and electrical conductivity (EC) from surface runoff and soil erosion sources. PCA and factor analysis (PCA/FA) revealed two main groups, distinguished by natural and anthropogenic sources, responsible for water quality variations. Hierarchical cluster analysis (HCA) grouped sampling sites into three clusters: low, moderate, and high pollution areas in the R-NO and unpolluted, low, and moderate pollution areas in the R-AD. The order of dominant cations was Mg2+ > Ca2+ > K+ and HCO3− > Cl− > SO42− for anions. Based on Piper diagram classification, watersheds studied were predominated by the Mg-Ca-HCO3 water type in 85% (R-NO) and 79% (R-AD) of water samples. The chemical composition of shallow and deep water was dominantly controlled by the dissolution of silicates and carbonate, reverse ion exchange, and precipitation of calcite. These results reveal that diffuse pollution predominantly impacted the study sites during the rainy season, and this should be the focus of policymakers when planning and implementing measures to protect drinking water sources, human health, and reduce water treatment costs.

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Milev, Borislav P., Maria A. Patras, Thorsten Dittmar, Gino Vrancken, and Nikolai Kuhnert. "Fourier transform ion cyclotron resonance mass spectrometrical analysis of raw fermented cocoa beans of Cameroon and Ivory Coast origin." Food Research International 64 (October 2014): 958–61. http://dx.doi.org/10.1016/j.foodres.2014.07.012.

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7

Alakeh, Mofor Nelson, Tangoh Frinde Adeline, Mbene Kenneth, Fai Joel Alongifor, and Njoyim Estella Buleng Tamungang. "Effects of Effluent on Cultivated Soil Properties in Kedjoum Ketinguh, Northwest Region of Cameroon." East African Journal of Environment and Natural Resources 7, no. 1 (2024): 200–213. http://dx.doi.org/10.37284/eajenr.7.1.2009.

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This study assessed the physicochemical and heavy metal properties of cultivated soils contaminated by effluent and uncontaminated soils in Mphiewen-Kedjoum Ketinguh, Northwest region of Cameroon, in the rainy and dry seasons respectively. In addition, the physicochemical and heavy metals properties of effluent from Mphiewen, responsible for contamination of Mphiewen soil were assessed. We hypothesized that heavy metals from the effluent affected the cultivated soil and plants grown on it. All analyses were carried out on the soil and effluent samples using standard analytical methods. The results revealed that, the soil samples had pH values ranging from 5.9 to 6.0. The effluent sample had pH value of 5.9 and 6.9 in rainy and dry seasons respectively. The organic matter levels in the soils were high and ranged from 5.0-8.92% in both seasons. Total nitrogen content in all the soils were low (N < 1%) and ranged from 0.1 to 0.3%. C/N ratios were high (ranging from 15 to 17), indicating that the organic matter was inadequately mineralized. Heavy metals analysis showed that the cultivated soil was contaminated by cadmium with total concentration of 3.7 mg/kg in the dry season, and chromium with total concentrations of 100.05 and 105.49 mg/kg in rainy and dry seasons respectively. Pearson correlation between some physicochemical properties of the contaminated soil and effluent physicochemical properties were all unity (r = 1.000; p < 0.01). This indicated that the effluent from the dumpsite was the main source of contaminant in the cultivated soil receiving the effluent. The problem of Cd and Cr toxicity in the contaminated soil can be solved by using various methods based on physical, chemical, and biological processes such as chemical precipitation, membrane separation, ion exchange, electrodialysis, phytoremediation, and surface adsorption

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8

Mvondo, S., J. F. Beyala Ateba, G. H. Ben-Bolie, P. Owono Ateba, A. Simo, and H. F. Ekobena. "Dose estimates to the public due to 210Po ingestion via cocoa powder from Lolodorf high background radiation area, Cameroon." Radioprotection 53, no. 3 (2018): 193–98. http://dx.doi.org/10.1051/radiopro/2018022.

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210Po activity concentrations have been measured in Lolodorf high background radiation area in cocoa beans which are hand-processed into cocoa powder for breakfast purposes to estimate radiological dose to human. 210Po has been also measured in cocoa leaves and compared to the cocoa beans 210Po content. The analysis has been carried out by CANBERRA alpha spectrometry using ion-implanted silicon detectors. 210Po activity concentrations in cocoa beans varied from 2.31 ± 0.23 to 8.09 ± 0.56 Bq.kg−1, while these values varied from 21.7 ± 0.87 to 66.67 ± 1.58 Bq.kg−1 in cocoa leaves. The corresponding mean values are 4.96 ± 1.86 and 42.54 ± 16 Bq.kg−1 on a dry weight basis respectively. The obtained values confirm the fact that 210Po activity concentrations in cocoa leaves are high compared to the cocoa beans due to the deposition of 222Rn daughters in the atmosphere. The mean radiological doses to human were founded to be 0.227, 0.134, 0.083 and 0.062 mSv/year for children 2- to 7-year-olds, 7- to 12-year-olds, 12- to 17-year-olds and for adult respectively. Ingestion of cocoa powder by the most exposed group ages (children) might not exceed the recommended dose limit for members of the public, which is 1 mSv/year.

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9

Yves Mann Elate Lea Mbassi, Marie Solange Evehe, Wilfred Fon Mbacham, and John Payne Muluh. "Identification and partial purification of thermally stable peroxidase isoenzymes from seedlings of Vigna sp. (V) landrace Vn." World Journal of Advanced Research and Reviews 12, no. 3 (2021): 476–83. http://dx.doi.org/10.30574/wjarr.2021.12.3.0706.

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Several soluble peroxidase isoenzymes are expressed in a landrace of Vigna sp. cultivated in the north of Cameroon (landrace called Vn in previous study) during seed germination. There are at least two cathodic peroxidases and eight major anodic peroxidases as shown by their electrophoretic migration at pH 7.4 under native conditions. These isoperoxidases are more expressed in roots than in shoots. They have different thermal stability, so that heat inactivation kinetics of crude peroxidase extracts from roots do not fit the first-order model. The slow and intermediate migrating groups of anodic isoperoxidases retains a substantial activity after ten minutes of incubation at 80°C and 85°C. An anodic isoperoxidase (named A6 in this study) shows in addition to this great thermal stability, a high activity in seedlings and is expressed both in roots and shoots. The combination of those characteristics makes this isoperoxidase a potential candidate for biotechnological applications. Three major anodic isoperoxidases, of which A6 and another thermostable isoperoxidase, were successfully separated from each other by ion exchange chromatography on DEAE-cellulose, after precipitation of total proteins by ice-cold acetone. This offers the prospect of being able to characterize these isoperoxidases individually in future studies.

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10

Adolphe, Kouoh Sone Paul-Michel, Tagne Guy Merlain, Lekene Ngouateu René Blaise, et al. "Kinetics and equilibrium studies of the adsorption of nickel (II) ions from aqueous solution onto modified natural and synthetic iron oxide." International Journal of Basic and Applied Sciences 4, no. 3 (2015): 277. http://dx.doi.org/10.14419/ijbas.v4i3.4721.

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<p>The present paper reports on the kinetic and equilibrium studies of the adsorption of Nickel(II) ions from aqueous solution onto modified natural iron oxide (NAT) from Mbalam (East Region of Cameroon) and synthetic iron oxide (SYNTH). The parameters investigated using batch techniques include, the contact time, adsorbent mass, pH and initial metal ion concentration. The experimental results obtained showed that, the optimum pH of 6 for bothadsorbents with an equilibrium time of 30 minutes was sufficient. The kinetic data correlated well with the pseudo-first-order and pseudo-second-order kinetic models for both the adsorbents based on the correlation coefficients (R<sup>2</sup>) obtained. The adsorption processes followed both the Langmuir and the Tempkin adsorption models for the natural iron oxide, whereas the Freundlich and Tempkin adsorption models fitted well the adsorption data for the synthetic iron oxide. The maximum quantity of Nickel(II) ions adsorbed was 250 mg/g for the two adsorbents. These results revealed a high adsorption capacity of natural iron oxide which is comparable to that of synthetic iron oxide.</p>

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Academic literature on the topic 'Ion – Cameroon'

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