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Search Results: 1 - 10 of 10023 matches for " Simon Ngomba Longonje "
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Seasonal Variations in Groundwater of the Phreatic Aquiferous Formations in Douala City-Cameroon: Hydrogeochemistry and Water Quality  [PDF]
Richard Ayuk Akoachere, Sonia Ebot Egbe, Thomson Areapkoh Eyong, Sophie Ngomune Edimo, Simon Ngomba Longonje, Diana Besem Tambe, Nji Bihmimihney Nelly
Open Access Library Journal (OALib Journal) , 2019, DOI: 10.4236/oalib.1105328
Abstract:
This study was to determine the seasonal variations of groundwater, the influence of the rock formations on the groundwater solute chemistry and groundwater domestic-agro-industrial quality using hydrogeochemical tools and physicochemical parameters; Ionic ratios, Gibbs diagrams, Piper diagrams, Durov diagrams and water quality indices. From physicochemical parameters; in the rainy season, pH ranged from, 4.6-7.1; EC, 0.023-1.63 mS/cm; Temperature, 26.3-290C andTDS, 0.015-1.09 mg/L and in the dry season pH ranged from 5-7.2; EC, 0.01-1.61 mS/cm; Temperature, 24.4-29.50C andTDS, 0.01-1.08 mg/L. Forty groundwater samples; 20 per season, wet and dry were analysed. Themajor ions fell below WHO acceptable limits for both seasons. The sequences of abundance of major ions were, Ca2 >K >Mg2 >NH4 >Na , HCO3->Cl->SO42->NO3->HPO42- in wet season and Ca2 >Mg2 >K >Na >NH4 , HCO3->Cl->SO42->HPO42->NO3- in dry season. Ion-exchange, simple dissolution and uncommon dissolution processes determined groundwater character. Groundwater ionic content was as a result of ion exchange from rock-weathering. Water types are; MgCl and MgHCO3 in both seasons. Hydrogeochemical facies are; Ca-Mg-Cl-SO4, characteristic of groundwater some distance along its flow path and Ca-Mg-HCO3, characteristic of freshly recharged groundwater from precipitation. The groundwater indices of; Sodium Percent (% Na), Residual Sodium Carbonate (RSC) , Kelley’s ratio (KR), Sodium Adsorption Ratio (SAR), Electrical Conductivity (EC), Total Dissolved Solid (TDS), USSL? and Wilcox index were determined, evaluated and found to be suitable for agro-industrial uses in all seasons. Permeability Index (PI) , Water quality index (WQI) and Magnesium Adsorption Ratio (MAR) were not suitable in some areas and in some seasons.
Trace Metals in Groundwater of the South Eastern Piedmont Region of Mount Cameroon: Quantification and Health Risk Assessment  [PDF]
Richard Ayuk Akoachere, Edwin Ngwene Etone, Roy Lyonga Mbua, Marcelle Pami Ngassam, Simon Ngomba Longonje, Pius Mbu Oben, Regina Wotany Engome
Open Access Library Journal (OALib Journal) , 2019, DOI: 10.4236/oalib.1105327
Abstract:
The South Eastern Piedmont Region of Mount Cameroon is getting in-creasingly populated. Groundwater is the main resource for drinking in this area; hence, the quantification of trace metals, suitability and quality of the groundwater resources for drinking, domestic and agro-industrial uses is of public and scientific concern. In this study, 10 samples were collected from 10 sites in September 2017. Field measurement of physicochemical parameters and investigation of the levels of trace metal content in groundwater was determined using Inductively Coupled Plasma Mass Spectroscopy ICP-MS. R-mode statistical analysis has been done and traces metals elements correlated with the physicochemical parameters and cluster analysis PCA carried out. The paper also highlights and determines the average daily dose ADD, the carcinogenic risks CR and the non-carcinogenic risk hazard quotient HQ which yields the hazard indices HI. The general trend of mean trace metal concentration in the sampled groundwater was in the order of: Zn > Fe > Al > V > Mn > Cu > Cr > Ni > Pb > As > Co > Cd > Sb. All the groundwater risk indices; ADD, CR, HQ and HI were less than 1 in categories of insignificant health risk. The severity of metal toxicity is governed by several factors, such as dose, nutrition, age, and even life style. Therefore, this low trend might not guarantee the complete absence of human health risk. Generally, from risk assessment on trace metals using risk indices, the analyzed water samples might not be at an alarming health risk. However, due to an increasing level of environmental pollution that might be imposed by increasing human activity in this region, water sources might become a potential sink of contaminants; this is significant reason that makes constant monitoring, implementation and treatment of groundwater for drinking purposes obligatory.
Commercial activities and subsistence utilization of mangrove forests around the Wouri estuary and the Douala-Edea reserve (Cameroon)
Adolphe Atheull, Ndongo Din, Simon N Longonje, Nico Koedam, Farid Dahdouh-Guebas
Journal of Ethnobiology and Ethnomedicine , 2009, DOI: 10.1186/1746-4269-5-35
Abstract: Semi-structured interviews were conducted with 120 active mangrove loggers in 23 Douala wood markets and 103 households located in three villages (Mbiako, Yoyo I and Yoyo II) close to Douala-Edea reserve. In each of the three densely populated villages, every second household was chosen for sampling while in all markets, mangrove loggers were chosen randomly. In addition, log diameters were measured in each market using a wooden foldable tape measure. A post hoc analysis (Newman-Keuls test) was performed in order to detect the common wood class diameter sold in the Douala wood markets.The analysis of the loggers' survey data has shown that large logs of Rhizophora with diameter greater than 40 cm were common in the Douala wood markets and were more closely associated with loggers who used chainsaws. In addition to the general mangroves wood products selling, the analysis on a subsistence level (households' survey) suggests the local population's dependence on mangroves, with multiple uses of Rhizophora racemosa Meyer, R. harrisonii Leechman, Avicennia germinans L. Stearn., Laguncularia racemosa Gaertn. f. and Conocarpus erectus L. timbers for furniture, fences, smoking fish, and fuelwood. Finally, Nypa fruticans (Thunb.) Wurmb. leaves were used as thatching material for house walls and roofs.Our findings revealed that big logs of Rhizophora were commonly sold by the loggers. A majority of loggers (60%) reported that mangrove marketed wood constitute a principal source of income. Most of the villagers (85.83%) often depend on mangroves for subsistence needs and for them there is no substitute for mangrove wood. Therefore, more efforts should be undertaken at the national level to implement conservation, management and sustainable use of these coastal forests.Throughout the world, mangroves are among the most productive ecosystems because of their exceptional flora and fauna diversities [1-6]. These forested wetlands are socio-economically and ecologically important f
Stephen Coleman & Karen Ross: The Media and the Public: ‘Them’ and ‘Us’ in Media Discourse. West Sussex: Wiley-Blackwell. 2010.
Teke J Ngomba
MedieKultur : Journal of Media and Communication Research , 2012,
Abstract:
Norma Pecora, Enyonam Osei-Hwere & Ulla Carlsson (Eds.): African media, African children. Gothenburg: The International Clearinghouse on Children, Youth and Media, NORDICOM. 2008
Teke J Ngomba
MedieKultur : Journal of Media and Communication Research , 2010,
Abstract:
Discourses of positionality and the challenges of democratization in the global south: The case of Nepal and Cameroon
Jacob Thorsen,Teke J Ngomba
MedieKultur : Journal of Media and Communication Research , 2012,
Abstract: In this article, we argue that to conceptually and empirically grasp the dynamics and challenges of processes of civic participation, i.e., the deliberation and empowerment of disenfranchised and marginalized populations in the Global South, communication for social change scholars need to pay more attention to three issues: the quality of citizens’ self-perceptions in relation to their local milieu, inter-citizen perceptions and relations at the local level and lastly, the attendant consequences of these on citizens’ sense of efficacy. To grasp and comprehend the interplay of these three issues, we propose the adoption of Floya Anthias’ concept of narratives of location and positionality and demonstrate the heuristic vitality of this notion through a discussion of some local discourses of positionality in Nepal and Cameroon.
MGluR5 Mediates the Interaction between Late-LTP, Network Activity, and Learning
Arthur Bikbaev, Sergey Neyman, Richard Teke Ngomba, Jeffrey Conn, Ferdinando Nicoletti, Denise Manahan-Vaughan
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0002155
Abstract: Hippocampal synaptic plasticity and learning are strongly regulated by metabotropic glutamate receptors (mGluRs) and particularly by mGluR5. Here, we investigated the mechanisms underlying mGluR5-modulation of these phenomena. Prolonged pharmacological blockade of mGluR5 with MPEP produced a profound impairment of spatial memory. Effects were associated with 1) a reduction of mGluR1a-expression in the dentate gyrus; 2) impaired dentate gyrus LTP; 3) enhanced CA1-LTP and 4) suppressed theta (5–10 Hz) and gamma (30–100 Hz) oscillations in the dentate gyrus. Allosteric potentiation of mGluR1 after mGluR5 blockade significantly ameliorated dentate gyrus LTP, as well as suppression of gamma oscillatory activity. CA3-lesioning prevented MPEP effects on CA1-LTP, suggesting that plasticity levels in CA1 are driven by mGluR5-dependent synaptic and network activity in the dentate gyrus. These data support the hypothesis that prolonged mGluR5-inactivation causes altered hippocampal LTP levels and network activity, which is mediated in part by impaired mGluR1-expression in the dentate gyrus. The consequence is impairment of long-term learning.
An Instance of Somatoform Disorder  [PDF]
Armando Simon
Open Journal of Medical Psychology (OJMP) , 2013, DOI: 10.4236/ojmp.2013.21004
Abstract: A case study is presented of a prison inmate with Somatoform Disorder, a relatively rare type of mental illness. In this particular case symptomatology revolved around his claim that some of his teeth were rotten, resulting in great pain, in spite of several diagnoses by dentists. When said teeth were extracted, inmate would express satisfaction, whereupon several weeks later the same complaint would resurface and the cycle began anew. Of the various types of mental illnesses listed in the DSM, there are some that are infrequently seen [1,2] One of these is Somatoform Disorder, a category of mental illness for which there is a paucity of research, partly due to diagnostic difficulties and controversies [3,4] and we would like to present a case study of just such an instance.
Model for a UV Laser Based Local Polymer Surface Halogenation Process Using a Gaseous Precursor  [PDF]
Simon Kibben
Modeling and Numerical Simulation of Material Science (MNSMS) , 2014, DOI: 10.4236/mnsms.2014.41003
Abstract: An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.
Dehumanization, Racial Minority and Female Leadership: An Analysis of Global Trends  [PDF]
Simon Raymond
Advances in Applied Sociology (AASoci) , 2016, DOI: 10.4236/aasoci.2016.68022
Abstract: Purpose: The use of dehumanization, directed toward racial minorities, impresses as a global trend of significance, spanning from broad generalisations with regards to black community members holding a lower status through to Russian politicians terming Barack Obama and Michelle Obama as mammalian apes (or, monkeys). This report analyses the use of dehumanization and the validity of racial degradation. Female leadership is also analysed. Methods: A comparative analysis was performed assessing the achievements of African Americans in comparison with white (including caucasian) society, with a gender comparison to assess for consistency across genders. The categorisation of racial minorities based on the satisfying of criteria for conscious being recognition was also considered. Results: African Americans have held positions, and achieved success, equally respectable with that of the white (including caucasian) community. These members of society also satisfy the criteria for conscious beings. There appears to be no validity to support black or Asian people as representative of a being less than that of a human being. Conclusion: There appears to be no validity behind categorisation of certain races as lesser members of society. Furthermore, there appears no validity behind the use of dehumanization.
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