Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 3 )

2018 ( 7 )

2017 ( 11 )

2016 ( 9 )

Custom range...

Search Results: 1 - 10 of 2135 matches for " Gilles Nyuyki Ngoran "
All listed articles are free for downloading (OA Articles)
Page 1 /2135
Display every page Item
Carbonate Enrichment in Volcanic Debris and Its Relationship with Carbonate Dissolution Signatures of Springs in the Sabga-Bamessing, North West, Cameroon  [PDF]
Raymond Beri Verla, Germain M. M. Mboudou, Olivier Njoh, Gilles Nyuyki Ngoran, Aloysius Ngambu Afahnwie
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.51012

Sabga-Bamessing is a part of the Bamenda Mountains, an extinct volcanic center of the West Cameroon Highlands along the Cameroon Volcanic Line (CVL). The pristine volcanic rocks of the Sabga area are alkali mafic to felsic (basanites, phonolites, trachytes and rhyolites). Some weathered sections of a heterolithologic debris flow with a suppositious primary chemistry of the original volcanic rocks prior to weathering have shown significant calcium carbonate enrichment. CaO and LOI values of up 61.31% and 41.72% respectively show corresponding enrichment of 16.54 and 10.88, when compared with average fresh volcanic rocks. Na+ normalized molar ratios computed from the chemistry of springs and rivers show carbonate dissolution signature which is contrary to silicate dissolution expected in acid volcanic rocks. Saturation indices (SI) calculated with PHREEQC reveal that brackish to saline springs are supersaturated with Calcite (CaCO3), Aragonite (CaCO3), Dolomite (CaMg(CO3)2 and Hydroxyl apatite (Ca5(PO4)3OH). Recharging contributions to spring water chemistry deviate from those produced by rock weathering, precipitation and evaporation/crystallization. An enrichment process

Petrochemistry of Two Magnetite Bearing Systems in the Precambrian Belt of Southern Cameroon  [PDF]
Gilles Nyuyki Ngoran, Cheo Emmanuel Suh, Dunkan Bowker, Raymond Beri Verla, Godlove Tasin Bafon
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.74038
Abstract: In the past decades, several iron ore occurrences have been discovered in the Precambrian Belt of southern Cameroon, with focus on their economic potential, and little attention on the deposit type. However, few studies have been geared towards understanding the different deposit types within this region. This paper seeks to provide new insight on the different styles of iron ore mineralisation of two potential, yet least studied iron ore deposits in this region in addition to enhancing exploration efforts within the different prospects. Petrology and geochemistry of rock samples from the Binga and Djadom iron prospects in southern Cameroon are investigated. The structural disposition of the prospects was mapped and cores described, sampled and subsequently analysed to enhance the understanding of the alteration mineralogy, ore mineralogy and textural features of the iron-bearing lithologies. Polished thin sections were studied by standard microscopy while the bulk rock geochemistry was determined by X-ray fluorescence (XRF) for major and trace elements. At Binga, the main rock types are magnetite gneisses, amphibolites, quartz-biotite gneisses, and mafic intrusions, while the main rocks encountered at Djadom are magnetite gneisses, amphibolitic BIFs, quartz-biotite gneisses, amphibolites and fault rocks. At both prospects, the target lithology for iron ore is the magnetite gneiss. The magnetite gneisses at the Binga prospect are weakly to moderately foliated, but strongly foliated at Djadom, and both contain fractures that are healed by irregular magnetite. Magnetite is anhedral to euhedral in outline and it is closely associated with amphibole, garnet and pyroxene. Iron content of the magnetite gneisses ranges from 17.44 - 33.40 wt% (at Binga) and 27.73 - 43.39 wt% (at Djadom) and the ore enrichment process involved progressive loss of silica and aluminium. Trace element concentrations show high contents of Ba, Zn, Cu and V but lower abundances of Sr and Zr, as well as low values for Ti in both prospects. At the Binga iron ore prospect, TiO2 and Al2O3
Nephroblastoma: Radiological and Pathological Diagnosis of a Case with Liver Metastases  [PDF]
Kouamé Ngoran, Doukouré Brahima, Manewa Fotso Sorelle, Gaimou Blé P, Yessoufou Bakary Nafissath, N’Goan-Domoua Anne-Marie
Open Journal of Radiology (OJRad) , 2016, DOI: 10.4236/ojrad.2016.61004
Abstract: Nephroblastoma is one of the most common causes of abdominal-pelvic mass in children. It still raises a diagnostic problem because of the wide variety of causes of abdominal-pelvic mass but also because of the delays in consultation in sub-Saharan black Africa and consequently the discovery of the mass at a very late and sometimes metastatic stage. Yet nephroblastoma is a very chemo-sensitive malignancy requiring diagnosis at an early stage; a procedure in which medical imaging is essential. We report the case of a large abdominal-pelvic mass in a three-year-old girl in whom the abdominal-pelvic CT allowed to diagnose nephroblastoma with liver metastases. Our objective is to demonstrate the contribution of computed tomography in the diagnosis of large abdominal-pelvic mass of the child and discuss other causes of abdominal-pelvic mass of the child.
Traditional Medicine Followed at the Heart Institute of Abidjan  [PDF]
Fatoumata Traoré, Kamagaté Djenamba Bamba, Yves N’da Kouakou Ngoran, Florent Koffi, Marie Paule Mottoh, Soya Esaie, I. Coulibaly
World Journal of Cardiovascular Diseases (WJCD) , 2017, DOI: 10.4236/wjcd.2017.79027
Abstract: Objective: To determine the prevalence of the use of traditional medicine in?hypertensive patients and to identify the socio-demographic characteristics of these patients. Materials and Methods: This is a single cross-sectionalstudy with descriptive purpose that was carried out over a 4 month-period, from 1 January 2017 to 30 April 2017, in the outpatient department of the Heart Institute of Abidjan. It involved patients who consulted during this period for high blood pressure. An informed questionnaire was submitted to patients. A pre-test was performed on 20 patients prior to the start of the survey. Results: The prevalence was 34%, with a slight male predominance (52.4%). The average age of our patients was 51.7 years ± 20 years. Males (52.4%) and females (47.6%) were roughly in the same proportions in our study with a slight male predominance. Patients with a higher level of education used traditional medicine in 30.6% that is about one third of the cases. Nearly one third of the patients had a monthly income above 300,000 FCFA (28.5%). Almost half of the patients (45%) had social insurance coverage. Conclusion: The use of traditional medicine by hypertensive patients is a practice that exists and is growing rapidly. The profile of hypertensive patients using traditional medicine can be summarized as a young subject, a male with a higher education level, a high monthly income and social coverage. It is the place to insist on the therapeutic education of our hypertensive patients only way for a good control of the blood pressure figures.
Heart Failure with Preserved Ejection Fraction: A Report about 64 Cases Followed at the Heart Institute of Abidjan  [PDF]
Fatoumata Traore, Kamagaté Djenamba Bamba, Florent Koffi, Yves N’da Kouakou Ngoran, Marie Paule Mottoh, Soya Esaie, Iklo Coulibaly
World Journal of Cardiovascular Diseases (WJCD) , 2017, DOI: 10.4236/wjcd.2017.79026
Abstract: Objective: To describe the epidemiological and etiological features of heart failure with preserved ejection fraction in our context. Materials and Methods: This is a retrospective study that was carried out over a 12-monthperiod, from 1 January 2015 to 31 December 2015, in the hospitalization department of the Heart Institute of Abidjan. It was about patients hospitalized for heart failure who had received a dose of NT-proBNP and who had had an electrocardiogram, and a Doppler echocardiography. Heart failure with preserved ejection fraction (HFPEF) was defined from the symptoms and signs of heart failure, the level of NT-proBNP and from echocardiography data based on the left ventricular ejection fraction (LVEF) > 50%, the dilatation of the left atrium. The diastolic dysfunction of the left ventricle was assessed by the ratio E/E’ > 13. We defined as heart failure with decreased ejection fraction (HFDEF) symptoms and signs of heart failure and left ventricular dysfunction LVEF < 40%. A computer file was completed. It included epidemiological and etiological data. Results: The study involved sixty-four patients with heart failure with preserved ejection fraction out of 257 patients with heart failure that is a prevalence of 25%. The mean age was 57.3 ± 16 years. There was a male predominance that is 52% of cases. Congestive heart failure was predominant in 67%. NT-proBNP levels were 365 pg/ml on average. The average length of stay was 5.5 ± 3.1. Intra-hospital deaths were 4.6%. The etiologies are dominated by high
Yes, I Am Ready Now: Differential Effects of Paced versus Unpaced Mating on Anxiety and Central Oxytocin Release in Female Rats
Kewir D. Nyuyki, Martin Waldherr, Sandra Baeuml, Inga D. Neumann
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023599
Abstract: Sexual activity and partner intimacy results in several positive consequences in the context of stress-coping, both in males and females, such as reduced state anxiety in male rats after successful mating. However, in female rats, mating is a rewarding experience only when the estrous female is able to control sexual interactions, i.e., under paced-mating conditions. Here, we demonstrate that sex-steroid priming required for female mating is anxiolytic; subsequent sexual activity under paced mating conditions did not disrupt this anxiolytic priming effect, whereas mating under unpaced conditions increased anxiety-related behavior. In primed females, the release of the neuropeptide oxytocin (OT) within the hypothalamic paraventricular nucleus was found to be elevated and to further increase during paced, but not unpaced mating. Central administration of an OT receptor antagonist partly prevented priming/mating-induced anxiolysis indicating the involvement of brain OT in the anxiolysis triggered by priming and/or sexual activity. These findings reveal that the positive consequences of mating in females are dependent on her ability to control sexual interactions, and that brain OT release is at least in part the underlying neurobiological correlate.
Equilibrium Allele Distribution in Trading Populations  [PDF]
Gilles Saint-Paul
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.73012
Abstract: This paper extends the results of Saint-Paul (2007) regarding the long-run survival rates of alleles in trading populations, to a more general context where the number of loci is arbitrarily large under general assumptions about sexual reproduction. The central result is that fitness-reducing alleles can survive in a trading population, provided their frequency is not too large. However, the greater the number of loci that matter for fitness, the more stringent the conditions under which these alleles can survive.
Contribution of 18F-Fluoro-ethyl-tyrosine Positron Emission Tomography to Target Volume Delineation in Stereotactic Radiotherapy of Malignant Cranial Base Tumours: First Clinical Experience
Reinhold Graf,Michail Plotkin,Fonyuy Nyuyki,Peter Wust,Reinhard Wurm,Volker Budach,Winfried Brenner,Daniel Fahdt
International Journal of Molecular Imaging , 2012, DOI: 10.1155/2012/412585
Abstract: Increased amino acid uptake has been demonstrated in intracerebral tumours and head and neck carcinomas of squamous cell origin. We investigated the potential impact of using 18F-fluoro-ethyl-tyrosine (18F-FET)-PET/CT in addition to conventional imaging for gross tumour volume (GTV) delineation in stereotactic radiotherapy of skull base tumours. The study population consisted of 14 consecutive patients with cranial base tumours (10 with squamous cell histology, 4 others). All patients underwent a FET-PET/CT examination in addition to contrast-enhanced CT and 11 patients underwent MRI. All tumours and histologic types showed increased FET uptake. The GTV was defined by all voxels showing hyperintensity in MRI or CT (GTVMRI/CT) or enhancement in PET (GTVPET), forming a GTVcomposite that was used for the initial treatment fields. An additional volume of infiltrative growth outside the GTVMRI/CT of about 1.0 ± 2 cm3 (5% of the conventional volume) was demonstrated by FET-PET only (GTVPETplus) with significant enlargement (>10% of GTVMRI/CT) in three patients. From existing data, we found correlation between cellular density and the standardized uptake value (SUV) of FET. We were able to substantially reduce the volume of escalated radiation dose (GTVboost) by 11 ± 2 cm3 (24%) of the conventional volume. 1. Introduction It is assumed that the larger part of geometrical uncertainties in fractionated stereotactic radiotherapy (FSRT) is due to delineation errors during the treatment planning procedure [1]. This is especially serious if the errors lead to marginal tumour misses, resulting in a dismal prognosis, or to enlargement of the volume treated, increasing the frequency of severe late effects. Structures of the skull base (SB) with high signal intensity and high contrast-enhancement in magnetic resonance imaging (MRI) make it difficult to differentiate tumour tissue from normal structures [2] and to exactly delineate the target volume. Therefore, although costly, functional imaging is increasingly used for target volume delineation in SB radiotherapy. The diagnostic value of 2-((18)F)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for imaging intracranial tumours is hampered by the low imaging contrast between tumourous tissue and that of the normal brain due to the high glucose utilization of both and this may also be true for SB tumours and the neighbouring brain tissue [3]. The newly introduced tracer O-(2-[18F] Fluoro-Ethyl)-L-Tyrosine (18F-FET) allows a more precise estimation of intracerebral tumour borders than MRI [4]. Pauleit et
éditorial : Monitoring pour le stockage du CO2 et la production des hydrocarbures Editorial: Monitoring of CO2 Sequestration and Hydrocarbon Production
Kimmerlin Gilles,Munier Gilles
Oil & Gas Science and Technology , 2012, DOI: 10.2516/ogst/2011178
Impact of some climatic and phenological parameters on the callogenesis and somatic embrogenesis variations in coco
AE Issali, A Traoré, N Diarrassouba, J Andi Kohi Ngoran, A Sangaré
African Crop Science Journal , 2012,
Abstract: Callogenesis and somatic embryogenesis (SE) are influenced by several factors including climate and phenology. To assess such an influence, the percentage of callogenesis and SE variations depending on five climatic and two phenological parameters was measured for 2 years. Staminodes and petals from six hybrids and two clones ascontrols were cultured in bulk, onto three distinct calli induction media only differing in hormonal concentrations.From the results, it emerged that sole leaves flush does not vary from year to year. Maximal temperature and flowering level are the most stably linked. Non-linear regression provides the best R2-values of fitted curves. This shows that the link among climate, phenology, callogenesis and SE is not linear. In the first year, in control clones,climatic and phenological parameters explain 52.80% callogenesis variations, against 31.50% for SE. Therefore,climate and phenology significantly influence callogenesis, but not SE. For further industrial production of secondary metabolites such as butter, the obromin and chocolate aroma from calli, it would be desirable also to identify the favourable periods for calli production. Nevertheless, somatic embryos will continue to be produce all the year irrespective of period. Key Words: C te d’Ivoire, petals, staminodes
Page 1 /2135
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.