113 research outputs found
The interplay of dietary nutrient level and varying calcium to phosphorus ratios on efficacy of bacterial phytase: 2. Ileal and total tract nutrient utilization
The interplay of dietary nutrient specification and varying calcium to total phosphorus ratio on efficacy of a bacterial phytase: 1. Growth performance and tibia mineralization
First report on Basidiomycota fungi in sorghum and millet from Southwest Nigeria
Trametes species are mushroom fungi with several biotechnological applications. This includes
decolourisation of wastewater from olive mill and elimination of endocrine-disrupting hormones.This study
reports the presence of two Trametesspecies, namely Trametespolyzona and Trametesvillosa from the
phylumBasidiomycota in sorghum and milletvended inSouthwest Nigeria. These fungal isolates were
identified culturally and further identified through phylogenetic characterisation. Trametessp occurred in
10% of sorghum samples and 20% of millet samples. The two species were morphologically similar but
distantly related phylogenetically. Most fungal species present in cereal crops belong to the division
Ascomycota. However, two Trametesspecies belonging to division Basidiomycota are being reported for the
first time in cereal crops.Trametessp can be harnessed for their health benefits such as the treatment of
cancer and the reduction of viral activity in humans
Defluoridation of fluoride-rich groundwater in Mayo Tsanaga River Basin-Cameroon using locally produced bone char
With fluoride-rich groundwater causing a climatic-dependent fluorosis in Mayo-Tsanaga River Basin, the overall objective of this study was to reduce fluoride concentrations in drinking water to acceptable levels thereby improving the resilience of the population to this climate change induced pathology. The specific objectives were to: (1) assess water chemistry in the study area to re-affirm the undesirable fluoride levels; (2) assess the impact of seasons on the concentrations of fluoride; (3) construct and evaluate the performance of a household bone char-based adsorption defluoridation filter. A combination of hydrogeochemical and engineering analyses demonstrated that the groundwater is predominantly Ca+Mg-HCO3 type, which contains as much as 6.73 mg/l of undesirable concentrations of geogenic fluoride. These concentrations increased with elevated pH, electrical conductivity and in the dry season, and were reduced to less than 0.2 mg/l when the groundwater was subjected to filtration through 300 g of 0.2-0.8 mm faction of charred cow bones in a home-based defluoridation filter. The bone char in the filter can effectively reduce fluoride concentration to less than 0.7 mg/l, which is the local threshold limit, without negative impact on the organoleptic (taste, color and odor) characteristics of drinking water. Compared with the commercially activated carbon, the bone char has an additional capacity of adsorbing fluoride at a rate of 4 mg/liter in 30 minutes, which indicates that with a defined saturation time, the bone char filter can protect the population against climate change-induced fluoride enrichment in drinking water.Keywords: Groundwater. geogenic fluoride. climate dependent fluorosis. bone char defluoridation. water chemistr
Epilepsie chez les Enfants Atteints d’Infirmité Motrice Cérébrale : à Propos de 412 Observations à Yaoundé, Cameroun
Une étude prospective, descriptive et consécutive réalisée à l’Unité de Neurologie Pédiatrique de l’hôpital gynéco-obstétrique et pédiatrique de Yaoundé (Cameroun) du 1er janvier 2004 au 31 Décembre 2008 a permis de retenir 412 patients admis pour infirmité motrice cérébrale (IMC). L’IMC représentait 20,39% des pathologies neuropédiatriques. L’âge moyen des patients était de 31,7 mois. Les étiologies anténatales étaient de (5,51%), périnatales (65,25%), postnatales (29,22%) ; elles étaient dominées par l’asphyxie néonatale (43,68% de cas). L’épilepsie était l’une des principales affections associées à L’IMC. Elle était retrouvée chez 41,5% des patients. L’épilepsie était plus fréquente dans la tétraplégie spastique et l’hémiplégie cérébrale infantile. Par ailleurs 68,72% de patients ont fait la première crise épileptique au cours de leur première année de vie. Les convulsions néonatales, l’asphyxie néonatale et les infections néonatales ont été les facteurs de risque prédisposant les enfants avec IMC à faire l’épilepsie.Mots Clés enfants ; infirmité motrice cérébrale ; épilepsie ; Camerou
A situational analysis of agricultural production and marketing, and natural resources management systems in the humid tropical zones of Cameroon
Bacterial resistance to arsenic protects against protist killing
Protists kill their bacterial prey using toxic metals such as copper. Here we hypothesize that the metalloid arsenic has a similar role. To test this hypothesis, we examined intracellular survival of Escherichia coli (E. coli) in the amoeba Dictyostelium discoideum (D. discoideum). Deletion of the E. coli ars operon led to significantly lower intracellular survival compared to wild type E. coli. This suggests that protists use arsenic to poison bacterial cells in the phagosome, similar to their use of copper. In response to copper and arsenic poisoning by protists, there is selection for acquisition of arsenic and copper resistance genes in the bacterial prey to avoid killing. In agreement with this hypothesis, both copper and arsenic resistance determinants are widespread in many bacterial taxa and environments, and they are often found together on plasmids. A role for heavy metals and arsenic in the ancient predator–prey relationship between protists and bacteria could explain the widespread presence of metal resistance determinants in pristine environments
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Differential susceptibility of Onchocerca volvulus microfilaria to ivermectin in two areas of contrasting history of mass drug administration in Cameroon: relevance of microscopy and molecular techniques for the monitoring of skin microfilarial repopulation within six months of direct observed treatment
Background
Ivermectin is an excellent microfilaricide against Onchocerca volvulus. However, in some regions, long term use of ivermectin has resulted in sub-optimal responses to the treatment. More data to properly document the phenomenon in various contexts of ivermectin mass drug administration (IVM-MDA) is needed. Also, there is a need to accurately monitor a possible repopulation of skin by microfilariae following treatment. Skin snip microscopy is known to have a low sensitivity in individuals with light infections, which can be the case following treatment. This study was designed with two complementary objectives: (i) to assess the susceptibility of O. volvulus microfilariae to ivermectin in two areas undergoing IVM-MDA for different lengths of time, and (ii) to document the repopulation of skin by the O. volvulus microfilariae following treatment, using 3 independent diagnostic techniques.
Method
Identified microfilaridermic individuals were treated with ivermectin and re-examined after 1, 3, and 6 months using microscopy, actin real-time PCR (actin-qPCR) and O-150 LAMP assays. Susceptibility to ivermectin and trends in detecting reappearance of skin microfilariae were determined using three techniques. Microscopy was used as an imperfect gold standard to determine the performance of actin-qPCR and LAMP.
Results
In Bafia with over 20 years of IVM-MDA, 11/51 (21.6%) direct observe treated microfilaridemic participants were still positive for skin microfilariae after 1 month. In Melong, with 10 years of IVM-MDA, 2/29 (6.9%) treated participants were still positive. The microfilarial density reduction per skin biopsy within one month following treatment was significantly lower in participants from Bafia.
In both study sites, the molecular techniques detected higher proportions of infected individuals than microscopy at all monitoring time points. LAMP demonstrated the highest levels of sensitivity and real-time PCR was found to have the highest specificity.
Conclusion
Patterns in skin mirofilariae clearance and repopulation were established. O. volvulus worms from Bafia with higher number of annual MDA displayed a lower clearance and higher repopulation rate after treatment with ivermectin. Molecular assays displayed higher sensitivity in monitoring O. volvulus microfilaridemia within six months following treatment
Defluoridation of fluoride-rich groundwater in Mayo Tsanaga River Basin-Cameroon using locally produced bone char
With fluoride-rich groundwater causing a climatic-dependent fluorosis in Mayo-Tsanaga River Basin, the overall objective of this study was to reduce fluoride concentrations in drinking water to acceptable levels thereby improving the resilience of the population to this climate change induced pathology. The specific objectives were to: (1) assess water chemistry in the study area to re-affirm the undesirable fluoride levels; (2) assess the impact of seasons on the concentrations of fluoride; (3) construct and evaluate the performance of a household bone char-based adsorption defluoridation filter. A combination of hydrogeochemical and engineering analyses demonstrated that the groundwater is predominantly Ca+Mg-HCO3 type, which contains as much as 6.73 mg/l of undesirable concentrations of geogenic fluoride. These concentrations increased with elevated pH, electrical conductivity and in the dry season, and were reduced to less than 0.2 mg/l when the groundwater was subjected to filtration through 300 g of 0.2-0.8 mm faction of charred cow bones in a home-based defluoridation filter. The bone char in the filter can effectively reduce fluoride concentration to less than 0.7 mg/l, which is the local threshold limit, without negative impact on the organoleptic (taste, color and odor) characteristics of drinking water. Compared with the commercially activated carbon, the bone char has an additional capacity of adsorbing fluoride at a rate of 4 mg/liter in 30 minutes, which indicates that with a defined saturation time, the bone char filter can protect the population against climate change-induced fluoride enrichment in drinking water
Compositions and mobility of major, dD, d18O, trace, and REEs patterns in water sources at Benue River Basin-Cameroon: Implications for recharge mechanisms, geoenvironmental
Hydrogeochemical data are required for understanding of water quality, provenance and chemical composition
for the 2117700 km2 Niger River Basin. This study presents hydrogeochemical analysis of the Benue River Basin,
a major tributary of the Niger River. The distribution of, major ions, Si, δD and δ18O, Trace and Rare Earth
Elements (TE and REEs, respectively) composition in 86 random water samples, revealed mixing of, groundwater
with surface water to recharge shallow aquifers by July and September rains. Equilibration of groundwater with
kaolinite, and montmorillonites by, incongruent dissolution imprints hydrochemical signatures that vary from
Ca+Mg-NO3 in shallow wells to Na+K-HCO3 in boreholes and surface waters, with undesirable concentrations
of fluoride identified as major source of fluorosis in the local population. Our results further indicate nonisochemical
dissolution of local rocks by water, with springs, wells and borehole waters exhibiting surface watergaining,
weakest water-rock interaction, and strongest water-rock interaction processes, respectively. Poorly
mobile elements (Al, Th and Fe) are preferentially retained in the solid residue of incongruent dissolution, while
alkalis, alkaline earth and oxo-anion-forming elements (U, Mo, Na, K, Rb, Ca, Li, Sr, Ba, Zn, Pb) are more mobile
and enriched in the aqueous phase, whereas transition metals display an intermediate behaviour. Trace elements
vary in the order of Ba > Sr > Zn > Li > V > Cu > Ni > Co > As > Cr > Sc > Ti > Be > Pb > Cd, with Potentially
Harmful Elements such as Cd, As, and Pb mobilized in acidic media attaining near undesirable levels in populated
localities. With the exception of Y, REEs distribution in groundwater in the order of Eu > Sm > Ce >Nd > La >
Gd > Pr > Dy > Er > Yb > Ho > Tb > Tm, differ slightly with surface water composition. Post-Archean Average
Australian Shale normalized REEs patterns ranging from 1.08-199, point to the dissolution of silicates as key
sources of trace elements to groundwater, coupled to deposition by eolian dust
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