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Sample records for cameroon volcanic line

  1. Late Cretaceous intraplate silicic volcanism in the Lake Chad region: incipient continental rift volcanism vs. Cameroon Line volcanism

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    Shellnutt, G.; Lee, T. Y.; Torng, P. K.; Yang, C. C.

    2015-12-01

    The crustal evolution of west-central Africa during the Cretaceous was directly related to plate motion associated with the opening of the central Atlantic Ocean. Late Cretaceous (~66 Ma) to recent magmatism related to the Cameroon Line stretches from Northern Cameroon (i.e. Golda Zuelva) to the Gulf of Guinea (i.e. Pagalu) and is considered to be due to mantle-crust interaction. The volcanic rocks at Hadjer el Khamis, west-central Chad, are considered to be amongst the oldest volcanic rocks of the Cameroon Line but their relationship is uncertain because they erupted during a period of a regional extension associated with the opening of the Late Cretaceous (~75 Ma) Termit basin. The silicic volcanic rocks can be divided into a peraluminous group and a peralkaline group with both rock types having similar chemical characteristics as within-plate granitoids. In situ U/Pb zircon dating yielded a mean 206Pb/238U age of 74.4 ± 1.3 Ma and indicates the rocks erupted ~10 million years before the next oldest eruption attributed to the Cameroon Line. The Sr isotopes (i.e. ISr = 0.7050 to 0.7143) show a wide range but the Nd isotopes (i.e. 143Nd/144Ndi = 0.51268 to 0.51271) are more uniform and indicate that the rocks were derived from a moderately depleted mantle source. Major and trace elemental modeling show that the silicic rocks likely formed by shallow fractionation of a mafic parental magma where the peraluminous rocks experienced crustal contamination and the peralkaline rocks did not. The silicic rocks are more isotopically similar to Late Cretaceous basalts in the Doba and Bongor basins (i.e. ISr = 0.7040 to 0.7060; 143Nd/144Ndi = 0.51267 to 0.51277) of southern Chad than to rocks of the Cameroon Line (i.e. ISr = 0.7026 to 0.7038; 143Nd/144Ndi = 0.51270 to 0.51300). Given the age and isotopic compositions, it is likely that the silicic volcanic rocks of the Lake Chad area are related to Late Cretaceous extensional tectonics rather than to Cameroon Line magmatism.

  2. Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

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    Wotchoko Pierre

    2016-07-01

    Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

  3. A comparative review of petrogenetic processes beneath the Cameroon Volcanic Line:Geochemical constraints

    Institute of Scientific and Technical Information of China (English)

    Asobo N.E. Asaah; Tetsuya Yokoyama; Festus T. Aka; Tomohiro Usui; Mengnjo J. Wirmvem; Boris Chako Tchamabe; Takeshi Ohba; Gregory Tanyileke; J.V. Hell

    2015-01-01

    The origin and petrogenesis of the Cameroon Volcanic Line (CVL), composed of volcanoes that form on both the ocean floor and the continental crust, are difficult to understand because of the diversity, het-erogeneity, and nature of available data. Major and trace elements, and Sr-Nd-Pb isotope data of volcanic rocks of the CVL spanning four decades have been compiled to reinterpret their origin and petrogenesis. Volcanic rocks range from nephelinite, basanite and alkali basalts to phonolite, trachyte and rhyolite with the presence of a compositional gap between SiO2 58e64 wt.%. Similarities in geochemical characteristics, modeled results for two component mixing, and the existence of mantle xenoliths in most mafic rocks argue against significant crustal contamination. Major and trace element evidences indicate that the melting of mantle rocks to generate the CVL magma occurred dominantly in the garnet lherzolite stability field. Melting models suggest small degree (<3%) partial melting of mantle bearing (6e10%) garnet for Mt. Etinde, the Ngaoundere Plateau and the Biu Plateau, and<5%of garnet for the oceanic sector of the CVL, Mt. Cameroon, Mt. Bambouto, Mt. Manengouba and the Oku Volcanic Group. The Sr-Nd-Pb isotope sys-tematics suggest that mixing in various proportions of Depleted MORB Mantle (DMM) with enriched mantle 1 and 2 (EM1 and EM2) could account for the complex isotopic characteristics of the CVL lavas. Low Mg number (Mg# ¼ 100 ? MgO/(MgO þ FeO)) and Ni, Cr and Co contents of the CVL mafic lavas reveal their crystallization from fractionated melts. The absence of systematic variation in Nb/Ta and Zr/Hf ratios, and Sr-Nd isotope compositions between the mafic and felsic lavas indicates progressive evolution of magmas by fractional crystallization. Trace element ratios and their plots corroborate mantle het-erogeneity and reveal distinct geochemical signatures for individual the CVL volcanoes.

  4. Late Cretaceous intraplate silicic volcanic rocks from the Lake Chad region: An extension of the Cameroon volcanic line?

    Science.gov (United States)

    Shellnutt, J. G.; Lee, T.-Y.; Torng, P.-K.; Yang, C.-C.; Lee, Y.-H.

    2016-07-01

    Silicic volcanic rocks at Hadjer el Khamis, near Lake Chad, are considered to be an extension of the Cameroon volcanic line (CVL) but their petrogenetic association is uncertain. The silicic rocks are divided into peraluminous and peralkaline groups with both rock types chemically similar to within-plate granitoids. In situ U/Pb zircon dating yielded a mean 206Pb/238U age of 74.4 ± 1.3 Ma indicating the magmas erupted ˜10 million years before the next oldest CVL rocks (i.e., ˜66 Ma). The Sr isotopes (i.e., ISr = 0.7021-0.7037) show a relatively wide range but the Nd isotopes (i.e., 143Nd/144Ndi = 0.51268-0.51271) are uniform and indicate that the rocks were derived from a moderately depleted mantle source. Thermodynamic modeling shows that the silicic rocks likely formed by fractional crystallization of a mafic parental magma but that the peraluminous rocks were affected by low temperature alteration processes. The silicic rocks are more isotopically similar to Late Cretaceous basalts identified within the Late Cretaceous basins (i.e., 143Nd/144Ndi = 0.51245-0.51285) of Chad than the uncontaminated CVL rocks (i.e., 143Nd/144Ndi = 0.51270-0.51300). The age and isotopic compositions suggest the silicic volcanic rocks of the Lake Chad region are related to Late Cretaceous extensional volcanism in the Termit basin. It is unlikely that the silicic volcanic rocks are petrogenetically related to the CVL but it is possible that magmatism was structurally controlled by suture zones that formed during the opening of the Central Atlantic Ocean and/or the Pan-African Orogeny.

  5. Geohazards (floods and landslides) in the Ndop plain, Cameroon volcanic line

    Science.gov (United States)

    Wotchoko, Pierre; Bardintzeff, Jacques-Marie; Itiga, Zénon; Nkouathio, David Guimolaire; Guedjeo, Christian Suh; Ngnoupeck, Gerald; Dongmo, Armand Kagou; Wandji, Pierre

    2016-07-01

    The Ndop Plain, located along the Cameroon Volcanic Line (CVL), is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually) and landslides (occasionally) occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people) tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide) maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered. The hazard maps revealed that 25% of the area is exposed to flood hazard (13% exposed to high flood hazard, 12% to moderate) and 5% of the area is exposed to landslide hazard (2% exposed to high landslide hazard, 3% to moderate). Some mitigation measures for floods (building of artificial levees, raising foundations of buildings and the meticulous regulation of the flood guards at Bamendjing Dam) and landslides (slope terracing, planting of trees, and building retaining walls) are proposed.

  6. Ambient noise tomography of the Cameroon Volcanic Line and Northern Congo craton: new constraints on the structure of the lithosphere

    Science.gov (United States)

    Guidarelli, M.; Aoudia, A.

    2016-03-01

    We investigate the lithospheric structure of Cameroon inverting Rayleigh waves obtained from the cross-correlation of ambient seismic noise. We correlate seismic records between 32 broad-band stations and we obtain good quality Rayleigh waves for 310 interstation paths. We measure group velocity dispersion curves from the reconstructed Rayleigh waves in the period range 10-35 s and we invert the group velocities for tomographic images. After the tomography the group velocities are then inverted, together with longer period group velocity measurements from existing literature, to compute a 3-D S-wave velocity model of the Cameroon lithosphere down to 100 km depth. Our results provide an unprecedented mapping of the physical properties of the different crustal units and their correlations with surface geology, as well as with mantle lithospheric variations. The Cameroon Volcanic Line (CVL) appears as a segmented feature exhibiting different physical properties along strike. The active Mt Cameroon volcano is underlain by very low velocities, unlike the other segments of the CVL. The along-strike variations in crustal structure suggest that lateral heterogeneities in lithospheric thickness and physical properties have influenced the location and distribution of magmatism. The crust beneath the Central African Shear Zone exhibits a sizeable low velocity anomaly. The lithosphere beneath Cameroon is characterised by a heterogeneous crust with a relatively constant thickness and a low velocity uppermost mantle at the edge of the Congo Craton. Our results favour processes combining small-scale upwelling at the edge of a thick lithosphere and reactivation of Precambrian basement structures to explain the distribution of Holocene-Recent magmatism and plateau uplift. Our results also indicate that Mt Cameroon and surroundings areas are the most at risk zones for magmatic activity during this stage of CVL development.

  7. Chemistry and origin of the Mayo Kila sapphires, NW region Cameroon (Central Africa): Their possible relationship with the Cameroon volcanic line

    Science.gov (United States)

    Paul Mbih, Kemeng; Meffre, Sebastien; Yongue, Rose Fouateu; Kanouo, Nguo Sylvestre; Jay, Thomson

    2016-06-01

    Mineralogical, chemical and geochronological studies constrained the origin of sapphires from Mayo Kila, Northwest Cameroon. The sapphires are mostly blue, with sizes ranging from 2 to 5 mm. The pale blue grains are transparent, whereas, other corundums are transparent to translucent and/or opaque. The sapphires are dominantly euhedral to sub-hedral with few polished lustrous grains, acquired features during moderate to short distance transport from a proximal source rock. Solid inclusions are limited to rutile and zircon. Trace element analysis of sapphires shows significant concentration (in ppm) in some elements: Fe (2208-14,473), Ti (82-1783), Ga (77-512), Mg (0.9-264.9), Cr (b.d.l -168) and V (1.3-82). The other elements (e.g. Sn, Nb, Ta, Th, Zr, Ni, Ce) are generally below 10 ppm. The calculated ratios for some of the selected elements show an extreme variation: Fe/Mg (43-3043), Fe/Ti (2-76), Ti/Mg (1-328), and Ga/Mg (0.4-363). They are dominantly corundum crystallized in alkaline magma (s) with few from metamorphic source (s). Trace elemental features with Hf (13,354-26,238 ppm), Th (4018-45,584 ppm) and U (7825-17,175 ppm), and Th/U (0.39-2.65) found in zircon inclusions are compatible with quantified values in magmatic crystallized zircons. The Cenozoic age (mean of 30.78 ± 0.28 Ma) obtained for zircon inclusions is close to the age of some igneous rocks found within the Cameroon Volcanic Line (e.g. rocks of the Mount Oku: 31-22 Ma), showing the same period of formation. The most probable source of the zircon host sapphires is the Oku Mountain located SW of Mayo Kila.

  8. Petrology and geochemistry of mantle xenoliths from the Kapsiki Plateau (Cameroon Volcanic Line): Implications for lithospheric upwelling

    Science.gov (United States)

    Tamen, Jules; Nkoumbou, Charles; Reusser, Eric; Tchoua, Felix

    2015-01-01

    Mantle xenoliths hosted by Oligocene alkaline basalts of the Kapsiki Plateau, northern end of the Cameroon Volcanic Line consist of group I spinel and plagioclase peridotites, mainly protogranular and accessorily porphyroclastic. The sub-continental lithospheric mantle here is heterogeneous and encloses both depleted and fertile components. Minerals exhibit wide range major element compositions compared to Nyos and Kumba grabens equivalent rocks. Spinel occurs as homogeneous brown crystals or as composite (brown-core-dark-rim) crystals when in contact with diopside or swatted in melt pools. Clinopyroxene crystals are either spinel exsolution-bearing or exsolution-free, the latter being often skeletal or frameworked and riddled with intracrystalline melt pools. Intraxenolith melt pockets and veinlets are always associated to plagioclase-bearing samples. Feldspars depict two distinctive compositions (An37-66Ab57-32Or6-2 and An3-7Ab52-62Or31-48) partly attributed to host xenolith type and to the involvement in the spinel and/or diopside melting reaction of an infiltrating alkali and carbonate-rich liquid. Petrographic and geochemical data discriminate melt pockets from their host basalts, excluding thus infiltration of basaltic melt as prospective origin. Thermo-barometric estimates reveal that prior to their entrainment the Kapsiki mantle xenoliths experienced two P-T equilibrium stages resulting in subsolidus re-equilibration from spinel- to plagioclase-facies conditions. Furthermore mineral textural relations show that the occurrence of plagioclase and melts inclusions is linked to spinel and/or diopside breakdown, likely subsequent to decompression and/or metasomatic induced melting events predating Oligo-Miocene volcanism.

  9. Gas emission from diffuse degassing structures (DDS) of the Cameroon volcanic line (CVL): Implications for the prevention of CO2-related hazards

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    Issa; Ohba, T.; Chako Tchamabé, B.; Padrón, E.; Hernández, P.; Eneke Takem, E. G.; Barrancos, J.; Sighomnoun, D.; Ooki, S.; Nkamdjou, Sigha; Kusakabe, M.; Yoshida, Y.; Dionis, S.

    2014-08-01

    In the mid-1980s, lakes Nyos and Monoun violently released massive gas, mainly magmatic CO2 killing about 1800 people. Subsequent geochemical surveys and social studies indicate that lakes Nyos and Monoun event is cyclic in nature and may occur anywhere in the about 37 other volcanic lakes located in the corridor of the Cameroon volcanic line (CVL). This potential threat motivated us to check if, alike Nyos and Monoun, the internal dynamic of the other lakes is also controlled by inputs of deep-seated-derived CO2 and attempt to measure and provide comprehensive insights on the passive gas emission along the CVL. This knowledge shall contribute to the prevention of volcanic lake-related hazards in Cameroon and the refinement of the Global Carbon Cycle. We used in situ fixation and dry gas phase sampling methods to determine CO2 origin and the concentration, and the accumulation chamber technique to measure diffuse CO2 emission from nine lakes and on soil at Nyos Valley and Mount Manenguba Caldera. The results suggest that, although in minor concentrations (compared to Nyos and Monoun), ranging from 0.56 mmol kg- 1 to 8.75 mmol kg- 1, the bottom waters of some lakes also contain measurable magmatic CO2 with δ13C varies from - 4.42‰ to - 9.16‰ vs. PDB. That finding implies that, under certain circumstances, e.g. increase to volcanic and/or tectonic activities along the CVL, the concerned lakes could develop a Nyos-type behavioural scheme. The diffuse gas emission results indicate that the nine surveyed lakes release approximately 3.69 ± 0.37 kt km- 2 yr- 1 of CO2 to the atmosphere; extrapolation to the approximately 39 volcanic lakes located on the CVL yields an approximate CO2 output of 27.37 ± 0.5 kt km- 2 yr- 1, representing 0.023% of the global CO2 output from volcanic lakes. In addition to the precedent value, the gas removal operation in lakes Nyos and Monoun released approximately 2.52 ± 0.46 × 108 mol km- 2 yr- 1 CO2 to the atmosphere from January

  10. Characterization of the sub-continental lithospheric mantle beneath the Cameroon volcanic line inferred from alkaline basalt hosted peridotite xenoliths from Barombi Mbo and Nyos Lakes

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    Pintér, Zsanett; Patkó, Levente; Tene Djoukam, Joëlle Flore; Kovács, István; Tchouankoue, Jean Pierre; Falus, György; Konc, Zoltán; Tommasi, Andréa; Barou, Fabrice; Mihály, Judith; Németh, Csaba; Jeffries, Teresa

    2015-11-01

    We carried out detailed petrographic, major and trace element geochemical, microstructural and FTIR analyses on eight characteristic ultramafic xenoliths from Nyos and Barombi Mbo Lakes in the continental sector of the Cameroon Volcanic Line (CVL). The studied xenoliths are spinel lherzolites showing lithologies similar to the other xenoliths reported previously along the CVL. They have protogranular and porphyroclastic textures. One of the Barombi xenolith contains amphibole, which had not been previously reported in this locality. Amphibole is common in the Nyos xenoliths suite. Peridotite xenoliths from both localities show some chemical heterogeneity, but Barombi xenoliths generally are less depleted in basaltic elements with respect to Nyos xenoliths. Trace element compositions of Nyos spinel lherzolites show a moderately depleted initial (premetasomatic) composition and variable enrichment in REE. Evidence for both modal and cryptic metasomatism is present in Nyos xenoliths. Rare earth element patterns of clinopyroxene suggest that interaction between mafic melts and the upper mantle occurred beneath the Nyos locality. Barombi Mbo xenoliths, on the other hand, record a small degree of partial melting. The Barombi Mbo xenoliths have weak, dominantly orthorhombic olivine crystal preferred orientations, whereas Nyos ones have strong axial-[010] patterns, which may have formed in response to transpression. Nominally anhydrous mantle minerals (NAMs) of the Barombi Mbo xenoliths show generally higher bulk concentrations of 'water' (70-127 ppm) than Nyos xenoliths (32-81 ppm). The Barombi Mbo xenoliths could originate from a juvenile segment of the lithospheric mantle, which had been originally part of the asthenosphere. It became a part of the lithosphere in response to thermal relaxation following the extension, forming a weakly deformed lower lithospheric mantle region along the CVL. The Nyos xenoliths, however, represent a shallow lithospheric mantle bearing

  11. Typology of Natural Hazards and Assessment of Associated Risks in the Mount Bambouto Caldera (Cameroon Line, West Cameroon)

    Institute of Scientific and Technical Information of China (English)

    Ghislain T. ZANGMO; Armand D. KAGOU; David G. NKOUATHIO; Pierre WANDJI

    2009-01-01

    Mount Bambouto is a polygenic stratovoicano of the Cameroon Volcanic Line, built between 21 Ma and 4.5 Ma. It is situated approximately 200 km NE of Mount Cameroon, between 09°55' and 10°15' longitude east and, 05°25' and 05°50' latitude north. The volcano covers an area of (13×8 km). Mount Bambouto is characterized by several natural hazards of different origins: meteorological, such as landslides and rock falls; anthropogenic, such as bushfires, tribal wars and deforestation; and volcanological, such as volcanic eruption. The thematic map shows that 55-60% of the caldera has high probability of occurrence of mass movement. The caldera has a high population density (3000 inhabitants), which increases the level of risk, evaluated at approximately $US3.8 million for patrimony, 3000 civilian deaths and destruction of biodiversity.

  12. Evaluation of groundwater quality and its suitability for drinking, domestic, and agricultural uses in the Banana Plain (Mbanga, Njombe, Penja) of the Cameroon Volcanic Line.

    Science.gov (United States)

    Ako, Andrew Ako; Shimada, Jun; Hosono, Takahiro; Ichiyanagi, Kimpei; Nkeng, George Elambo; Fantong, Wilson Yetoh; Eyong, Gloria Eneke Takem; Roger, Ntankouo Njila

    2011-12-01

    Groundwater quality of the Banana Plain (Mbanga, Njombe, Penja-Cameroon) was assessed for its suitability for drinking, domestic, and agricultural uses. A total of 67 groundwater samples were collected from open wells, springs, and boreholes. Samples were analyzed for physicochemical properties, major ions, and dissolved silica. In 95% of groundwater samples, calcium is the dominant cation, while sodium dominates in 5% of the samples. Eighty percent of the samples have HCO(3) as major anion, and in 20%, NO(3) is the major anion. Main water types in the study area are CaHCO(3), CaMgHCO(3), CaNaHCO(3), and CaNaNO(3)ClHCO(3). CO(2)-driven weathering of silicate minerals followed by cation exchange seemingly controls largely the concentrations of major ions in the groundwaters of this area. Nitrate, sulfate, and chloride concentrations strongly express the impact of anthropogenic activities (agriculture and domestic activities) on groundwater quality. Sixty-four percent of the waters have nitrate concentrations higher than the drinking water limit. Also limiting groundwater use for potable and domestic purposes are contents of Ca(2+), Mg(2+) and HCO(3) (-) and total hardness (TH) that exceed World Health Organization (WHO) standards. Irrigational suitability of groundwaters in the study area was also evaluated, and results show that all the samples are fit for irrigation. Groundwater quality in the Banana Plain is impeded by natural geology and anthropogenic activities, and proper groundwater management strategies are necessary to protect sustainably this valuable resource.

  13. Cameroon.

    Science.gov (United States)

    1992-06-01

    The US profile of Cameroon indicates brief statistics on the population, geography, government, and economy and brief descriptions of the population, the history, government, political conditions, the economy, foreign relations, defense, and relations with the US. Principal government and US officials are furnished. The 1991 estimated population of Cameroon was 11.7 million of which 60% is rural. There are 200 different tribes who speak many African languages and dialects. The French and English languages both have official status. Muslims live in the north and Christians in the south. 80% live in the formerly French east. The growth rate is 3%. There is 65% literacy. Infant mortality is 20%. 70% are agricultural workers, 13% industrial and commercial, and 17% other. The government is an independent republic with an executive and legislative branch. Independence was achieved in 1960. There is 1 ruling party. Traditional courts administer the laws. Traditional rulers are treated as administrative adjuncts. Suffrage is universal adult. The central government budget is 1.4 billion of which 8.7% is for defense. There are 10 provinces and 4 major cities. The seaport city Douala is the largest at 1.5 million. Gross domestic product (GDP) is $12.5 billion with an annual growth rate of 4.3% and an inflation rate of 2%. Growth has been variable since 1988 and reached a low of 2.4% in 1988-89. Oil, natural gas, bauxite, iron core, and timber are natural resources. 27% of the GDP is in agricultural products (cocoa, coffee, cotton, fishing, and forestry). 13% of the GDP is manufacturing and 24% is industry. Exports are valued at $2.9 billion and imports at $2.2 billion. Major markets are France, Netherlands, and the US. Imports include intermediate goods, capital goods, fuel and lubricants, foodstuffs, beverages, and tobacco. Early inhabitants were the Pygmies, followed later by Bantu speakers, and Muslim Fulani. Political consolidation was achieved in 1970 after a period of

  14. Potential and limitations of risk scenario tools in volcanic areas through an example at Mount Cameroon

    Directory of Open Access Journals (Sweden)

    P. Gehl

    2013-10-01

    Full Text Available This paper presents an integrated approach to conduct a scenario-based volcanic risk assessment on a variety of exposed assets, such as residential buildings, cultivated areas, network infrastructures or individual strategic buildings. The focus is put on the simulation of scenarios, based on deterministic adverse event input, which are applied to the case study of an effusive eruption on the Mount Cameroon volcano, resulting in the damage estimation of the assets located in the area. The work is based on the recent advances in the field of seismic risk. A software for systemic risk scenario analysis developed within the FP7 project SYNER-G has been adapted to address the issue of volcanic risk. Most significant improvements include the addition of vulnerability models adapted to each kind of exposed element and the possibility to quantify the successive potential damages inflicted by a sequence of adverse events (e.g. lava flows, tephra fall, etc.. The use of an object-oriented architecture gives the opportunity to model and compute the physical damage of very disparate types of infrastructures under the same framework. Finally, while the risk scenario approach is limited to the assessment of the physical impact of adverse events, a specific focus on strategic infrastructures and a dialogue with stakeholders helps in evaluating the potential wider indirect consequences of an eruption.

  15. Locating the depth of magma supply for volcanic eruptions, insights from Mt. Cameroon

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    Geiger, Harri; Barker, Abigail K.; Troll, Valentin R.

    2016-01-01

    Mt. Cameroon is one of the most active volcanoes in Africa and poses a possible threat to about half a million people in the area, yet knowledge of the volcano’s underlying magma supply system is sparse. To characterize Mt. Cameroon’s magma plumbing system, we employed mineral-melt equilibrium thermobarometry on the products of the volcano’s two most recent eruptions of 1999 and 2000. Our results suggest pre-eruptive magma storage between 20 and 39 km beneath Mt. Cameroon, which corresponds to the Moho level and below. Additionally, the 1999 eruption products reveal several shallow magma pockets between 3 and 12 km depth, which are not detected in the 2000 lavas. This implies that small-volume magma batches actively migrate through the plumbing system during repose intervals. Evolving and migrating magma parcels potentially cause temporary unrest and short-lived explosive outbursts, and may be remobilized during major eruptions that are fed from sub-Moho magma reservoirs. PMID:27713494

  16. Proposing a Theoretical GIS Model for Landslides Analysis : The Case of Mount Cameroon

    OpenAIRE

    Tambe-Ebot, Mathias Ashu Tako

    2011-01-01

    This study presents a theoretical GIS model to investigate the relative impacts of geomorphic and environmental factors that govern the occurrence of landslides on the slopes of Mount Cameroon and its surrounding areas. The study area is located along the Cameroon Volcanic Line (CVL), a major structural feature that originates from the south Atlantic and continues into the continental landmass. The quite frequent seismic activity, geologic character, humid tropical climate and high human pres...

  17. Tectonic evolution of the Tombel graben basement, southwestern Cameroon

    Institute of Scientific and Technical Information of China (English)

    M.S.Njome; C.E.Suh

    2005-01-01

    Planar structures (foliations and fractures) around the Tombel graben (southwestern end of the Central African Shear zone system) have been investigated and analyzed with the aim of unraveling the tectonic evolution of the basement. The foliations show two major trends, an older N-S-trending gneissose layering of uncertain agereworked by a later Pan-African (600 + 50 Ma) NE-SW ductile trend that is contemporaneous with sinistral shearing and mylonitization. The brittle phase characterized by NW-SE-trending open and partially filled fractures is younger than the mylonitization event and although it has not been dated, it is suggested that the origin of these fractures is linked to the onset of volcanism along the Cameroon volcanic line-31 m.y. ago.The mylonitic foliation is recognized for the first time and supports a tectonic evolution model for the Tombel graben in which ductile non-coaxial deformation was succeeded by brittle failure.

  18. Structure of the Crust beneath Cameroon, West Africa, from the Joint Inversion of Rayleigh Wave Group Velocities and Receiver Functions

    Energy Technology Data Exchange (ETDEWEB)

    Tokam, A K; Tabod, C T; Nyblade, A A; Julia, J; Wiens, D A; Pasyanos, M E

    2010-02-18

    The Cameroon Volcanic Line (CVL) is a major geologic feature that cuts across Cameroon from the south west to the north east. It is a unique volcanic lineament which has both an oceanic and a continental sector and consists of a chain of Tertiary to Recent, generally alkaline volcanoes stretching from the Atlantic island of Pagalu to the interior of the African continent. The oceanic sector includes the islands of Bioko (formerly Fernando Po) and Sao Tome and Principe while the continental sector includes the Etinde, Cameroon, Manengouba, Bamboutos, Oku and Mandara mountains, as well as the Adamawa and Biu Plateaus. In addition to the CVL, three other major tectonic features characterize the region: the Benue Trough located northwest of the CVL, the Central African Shear Zone (CASZ), trending N70 degrees E, roughly parallel to the CVL, and the Congo Craton in southern Cameroon. The origin of the CVL is still the subject of considerable debate, with both plume and non-plume models invoked by many authors (e.g., Deruelle et al., 2007; Ngako et al, 2006; Ritsema and Allen, 2003; Burke, 2001; Ebinger and Sleep, 1998; Lee et al, 1994; Dorbath et al., 1986; Fairhead and Binks, 1991; King and Ritsema, 2000; Reusch et al., 2010). Crustal structure beneath Cameroon has been investigated previously using active (Stuart et al, 1985) and passive (Dorbath et al., 1986; Tabod, 1991; Tabod et al, 1992; Plomerova et al, 1993) source seismic data, revealing a crust about 33 km thick at the south-western end of the continental portion of the CVL (Tabod, 1991) and the Adamawa Plateau, and thinner crust (23 km thick) beneath the Garoua Rift in the north (Stuart et al, 1985) (Figure 1). Estimates of crustal thickness obtained using gravity data show similar variations between the Garoua rift, Adamawa Plateau, and southern part of the CVL (Poudjom et al., 1995; Nnange et al., 2000). In this study, we investigate further crustal structure beneath the CVL and the adjacent regions in

  19. Structure of the Crust Beneath Cameroon, West Africa, from the Joint Inversion of Rayleigh Wave Group Velocities and Receiver Functions

    International Nuclear Information System (INIS)

    The joint inversion of Rayleigh wave group velocities and receiver functions was carried out to investigate the crustal and uppermost mantle structures beneath Cameroon. This was achieved using data from 32 broadband seismic stations installed for 2 years across Cameroon. The Moho depth estimates reveal that the Precambrian crust is variable across the country and shows some significant differences compared to other similar geologic units in East and South Africa. These differences suggest that the setting of the Cameroon Volcanic Line (CVL) and the eastward extension of the Benue Trough have modified the crust of the Panafrican mobile belt in Cameroon by thinning beneath the Rift area and CVL. The velocity models obtained from the joint inversion show at most stations, a layer with shear wave velocities ≥ 4.0 km/s, indicating the presence of a mafic component in the lower crust, predominant beneath the Congo Craton. The lack of this layer at stations within the Panafrican mobile belt may partly explain the crustal thinning observed beneath the CVL and rift area. The significant presence of this layer beneath the Craton, results from the 2100 Ma magmatic events at the origin of the emplacement of swarms of mafic dykes in the region. The CVL stations are underlain by a crust of 35 km on average except near Mt-Cameroon where it is about 25 km. The crustal thinning observed beneath Mt. Cameroon supported by the observed positive gravity anomalies here, suggests the presence of dense astenospheric material within the lithosphere. Shear wave velocities are found to be slower in the crust and uppermost mantle beneath the CVL than the nearby tectonic terrains, suggesting that the origin of the line may be an entirely mantle process through the edge-flow convection process. (author)

  20. The origin of the Line Islands: plate or plume controlled volcanism?

    Science.gov (United States)

    Storm, L. P.; Konter, J. G.; Koppers, A. A.

    2011-12-01

    Geochemical compositions of melts produced in the Earth's mantle provide key data for our understanding of the Earth's internal structure. Particularly, the range in compositions for oceanic intraplate volcanism has fueled the ongoing debate on the dynamic origin of hotspots. Traditionally, hotspots have been interpreted to originate from narrow, upwelling plumes of hot mantle material that reach the bottom of the tectonic plates. Progressively younger volcanoes, as seen at, for example, Hawaii, are then derived from plume melts. However, such a plume may originate from the core-mantle boundary, the top of seismically defined superplumes, or the origin may not lie in a buoyantly upwelling plume at all. The presence of an age progressive volcanic chain and a large igneous province, a high buoyancy flux, the geochemical composition of the erupted lavas, and seismically slow velocities have been used to distinguish different hotspot origins. Volcanic chains that lack most of these features may originate from the eruption of shallow melts along lithospherically controlled cracks. A unique area to study this type of volcanism is the Line Islands. These islands define a complex chain of volcanoes south of Hawaii that morphologically define multiple sub-groups. Moreover, recent age dating has revealed a complex geochronology. Combined geochronological and geochemical data from the Line Islands allude to the presence of shallow mantle melts that feed eruptions where there are weaknesses in the plates due to fractures or fissures. The Line Islands consist of elongated ridges, seamounts, atolls and islands that form the northern segment of the Line-Tuamotu chain of volcanoes. The volcanic chain is divided into three morphologically distinct regions; the northern, central and southern provinces. Long en echelon ridges of the Line Islands Cross Trend intersect the northern province at 14-16°N, which consists of the section between the Molokai and Clarion fracture zones. The

  1. First-line antiretroviral therapy and dyslipidemia in people living with HIV-1 in Cameroon: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Kengne André

    2011-09-01

    Full Text Available Abstract Background Data on lipid profile derangements induced by antiretroviral treatment in Africa are scarce. The aim of this study was to determine the prevalence and characteristics of lipid profile derangements associated with first-line highly active antiretroviral therapy (ART among Cameroonians living with human immunodeficiency virus (HIV infection. Methods This cross-sectional study was conducted between November 2009 and January 2010, and involved 138 HIV patients who had never received ART (ART-naive group and 138 others treated for at least 12 months with first line triple ART regimens that included nevirapine or efavirenz (ART group. Lipid profile was determined after overnight fast and dyslipidemia diagnosed according to the US National Cholesterol Education Program III criteria. Data comparison used chi-square test, Student t-test and logistic regressions. Results The prevalence of total cholesterol ≥ 200 mg/dl was 37.6% and 24.6% respectively in ART group and ART-naive groups (p = 0.019. The equivalents for LDL-cholesterol ≥ 130 mg/dl were 46.4% and 21% (p ≤ 0.001. Proportions of patients with total cholesterol/HDL-cholesterol ratio ≥ 5 was 35.5% in ART group and 18.6% in ART-naive group (p ≤ 0.001. The distribution of HDL-cholesterol and triglycerides was similar between the two groups. In multivariable analysis adjusted for age, sex, body mass index, CD4 count and co-infection with tuberculosis, being on ART was significantly and positively associated with raised total cholesterol, LDL-cholesterol and TC/HDL cholesterol. The adjusted odd ratios (95% confidence interval, p-value ART-treated vs. ART-naïve was 1.82 (1.06-1.12, p = 0.02 for TC ≥ 200 mg/dl; 2.99 (1.74-5.15, p Conclusions First-line antiretroviral therapy that includes nonnucleoside reverse transcriptase inhibitors is associated with pro-atherogenic adverse lipid profile in people with HIV-1 infection compared to untreated HIV-infected subjects in

  2. The Language Question in Cameroon

    OpenAIRE

    Echu, George

    2004-01-01

    In multilingual Cameroon, 247 indigenous languages live side by side with English and French (the two official languages) and Cameroon Pidgin English (the main lingua franca). While the two official languages of colonial heritage dominate public life in the areas of education, administration, politics, mass media, publicity and literature, both the indigenous languages and Cameroon Pidgin English are relegated to the background. This paper is a critique of language policy in Cameroon reveali...

  3. Republic of Cameroon

    OpenAIRE

    World Bank

    2015-01-01

    The overarching goal of this study is to facilitate Cameroon’s strategic objective of ensuring a well-educated human resources base in support of its quest to emerge as a strong middle-income economy by 2035. This study is intended to support Cameroon in preparing a national strategy for skills development, related policies, and institutions to boost competitiveness and productivity, and j...

  4. Mineral and geochemical characterization of a leptic aluandic soil and a thapto aluandic-ferralsol developed on trachytes in Mount Bambouto (Cameroon volcanic line)

    OpenAIRE

    Tematio, P.; Fritsch, Emmanuel; Hodson, M E; LUCAS, Y.; Bitom, D.; Bilong, P.

    2009-01-01

    Mineral and geochemical investigations were carried out on soil samples and fresh rock (trachytes) from two selected soil profiles (TM profile on leptic aluandic soils and TL profile on thapto aluandic-ferralsols) from Mount Bambouto to better understand geochemical processes and mineral paragenesis involved in the development of soils in this environment. In TM profile, the hydrated halloysites and goethite occur in the weathered saprolite boulders of BC horizon while dehydrated halloysite, ...

  5. The late holocene palaeoenvironment in the Lake Njupi area, west Cameroon: implications regarding the history of Lake Nyos

    Science.gov (United States)

    Zogning, Appolinaire; Giresse, Pierre; Maley, Jean; Gadel, François

    1997-04-01

    Lake Njupi, 1 km east of Lake Nyos, on the Cameroon Volcanic Line, was formed by the damming of a local crustal depression. Two cores from Lake Nyos were analysed which penetrated sediments at the margin of the lake. The older deposits give an age of 3400 years BP and this date is proposed as a minimum age for Lake Njupi. Sedimentological, palynological and geochemical studies of a 2 m section provide an opportunity to reconstruct the Late Holocene environmental history. It is an organic-rich deposit (organic carbon up to 30%) with an abundant Silicospongia spicules fraction. An obvious sedimentary homogeneity is interrupted by 5 fine to coarse layers with sandy quartz and lignitic remains. Such inputs were denoted by carbohydrate maxima or sometimes by phenolic compounds. This study confirms the evidence of an arid period culminating between 2500 and 2000 yrs BP. This crisis began around 3000 yrs BP in the rain forest area of West Cameroon and also further to the south in Congo. Lake Njupi, situated today in a mostly grassland savanna environment known as the "Grass Fields", provides evidence for environmental changes from a mosaic of forest and savanna before 2500 years BP to a savanna characterised by high grass pollen contents (75 to 85%), with small islands of forest. The mountain vegetation characterised by Podocarpus and Olea capensis retreated around 2300 years BP at the time Elaeis guineensis (the Oil Palm) began its extension as a pioneer tree, later providing opportunities for its domestication by man.

  6. A new Xylaria (Xylariaceae, Ascomycota) from Cameroon

    DEFF Research Database (Denmark)

    Læssøe, Thomas; Cheek, M.

    2002-01-01

    A new species of Xylaria (Xylariaceae, Ascomycota) from western Cameroon is described on teleomorphic and cultural characters.......A new species of Xylaria (Xylariaceae, Ascomycota) from western Cameroon is described on teleomorphic and cultural characters....

  7. Thanking Responders in Cameroon English

    Science.gov (United States)

    Ouafeu, Yves Talla Sando

    2009-01-01

    An analysis of authentic or genuine interactions among Cameroon English speakers reveals that conversational routines in this variety of English differ a good deal from those obtained in other varieties of English, non-native varieties of English inclusive, and more specifically in native varieties of English. This paper looks at "thanking…

  8. The Language Situation in Cameroon

    Science.gov (United States)

    Kouega, Jean-Paul

    2007-01-01

    This monograph examines the language situation in Cameroon, a Central African country where fewer than 20 million people speak close to 250 languages. Specifically, the monograph addresses the issues of language use and spread, language policy and planning, and language maintenance and prospects. The study is divided into five parts. The…

  9. The Language Question in Cameroon

    Directory of Open Access Journals (Sweden)

    Echu, George

    2004-01-01

    Full Text Available In multilingual Cameroon, 247 indigenous languages live side by side with English and French (the two official languages and Cameroon Pidgin English (the main lingua franca. While the two official languages of colonial heritage dominate public life in the areas of education, administration, politics, mass media, publicity and literature, both the indigenous languages and Cameroon Pidgin English are relegated to the background. This paper is a critique of language policy in Cameroon revealing that mother tongue education in the early years of primary education remains a distant cry, as the possible introduction of an indigenous language in the school system is not only considered unwanted by educational authorities but equally combated against by parents who believe that the future of their children lies in the mastery of the official languages. This persistent disregard of indigenous languages does not only alienate the Cameroonian child culturally, but further alienates the vast majority of Cameroonians who are illiterate (in English and French since important State business is carried out in the official languages. As regards the implementation of the policy of official language bilingualism, there is clear imbalance in the use of the two official languages as French continues to be the dominant official language while English is relegated to a second place within the State. The frustration that ensues within the Anglophone community has led in recent years to the birth of Anglophone nationalism, a situation that seems to be widening the rift between the two main components of the society (Anglophones and Francophones, thereby compromising national unity. The paper is divided into five major parts. After a brief presentation of the country, the author dwells on multilingualism and language policy since the colonial period. The third, fourth and last parts of the paper focus on the critique of language policy in Cameroon with emphasis first on

  10. Variation in stable isotope ratios of monthly rainfall in the Douala and Yaounde cities, Cameroon: local meteoric lines and relationship to regional precipitation cycle

    Science.gov (United States)

    Wirmvem, Mengnjo Jude; Ohba, Takeshi; Kamtchueng, Brice Tchakam; Taylor, Eldred Tunde; Fantong, Wilson Yetoh; Ako, Ako Andrew

    2016-04-01

    Hydrogen (D) and oxygen (18O) stable isotopes in precipitation are useful tools in groundwater recharge and climatological investigations. This study investigated the isotopes in rainfall during the 2013 and 2014 hydrological years in the Douala and Yaounde urban cities. The objectives were to generate local meteoric water lines (LMWLs), define the spatial-temporal variations of the isotopes in rainwater and their relationship to the regional precipitation cycle, and determine the factors controlling the isotopic variation. The LWMLs in Douala and Yaounde were δD = 7.92δ18O + 12.99 and δD = 8.35δ18O + 15.29, respectively. The slopes indicate isotopic equilibrium conditions during rain formation and negligible evaporation effect during rainfall. Precipitation showed similar wide ranges in δ18O values from -5.26 to -0.75 ‰ in Douala and -5.8 to +1.81 ‰ in Yaounde suggesting a common moisture source from the Atlantic Ocean. Enriched weighted mean δ18O (wδ18O) values during the low pre- and post-monsoon showers coincided with low convective activity across the entire region. Enriched isotopic signatures also marked the West African monsoon transition phase during each hydrological year. Abrupt wδ18O depletion after the transition coincided with the monsoon onset in the region. Peak periods of monsoonal rainfall, associated with high convective activities, were characterised by the most depleted wδ18O values. Controls on isotopic variations are the amount effect and moisture recycling. The stable isotope data provide a tool for groundwater recharge studies while the isotopic correlation with regional rainfall cycle demonstrate their use as markers of moisture circulation and detecting climatic changes in precipitation.

  11. Promotion and Development of Tourism in Cameroon

    OpenAIRE

    Frida-Tolonen, Frida

    2014-01-01

    This Bachelor’s thesis is aimed to achieve a main goal which is at Promoting and developing tourism in Cameroon. This work will give a broad overview of issues in tourism in Africa and Cameroon, suggesting guidelines to assist countries such as Cameroon, Namibia, Nigeria, to develop a more coherent structure for tourism. Tourism can only develop sustainably if it is united into the country’s overall economic, social and physical planning policies and enhancing regional promotion and effective...

  12. Leadership Style: School Perspective in Cameroon

    Directory of Open Access Journals (Sweden)

    Asan Vernyuy Wirba

    2015-01-01

    Full Text Available This paper examines leadership styles of secondary school principals in Cameroon, in terms of transformational, transactional, and laissez-faire leadership styles. This paper discusses the leadership styles in Cameroon and puts forward ideas for continuous improvement. A qualitative approach, using a semistructured interview, was adopted. It was conducted on ten principals, ten teachers, and ten students. Majority of respondents from schools described their principals as transformational leaders. Doubts are cast on the nature of transformational leadership in schools in Cameroon, since there is less training and development for leadership in schools.

  13. CPAFFC Delegation Visits Sierra Leone and Cameroon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>At the invitation of the Sierra Leone-China Friendship Association (SLCFA) and the Ministry of Territorial Administration and Decentralization of Cameroon, a 14-member CPAFFC delegation headed by Wang Daoyu, vice chairman of the Standing Committee of the Shandong Provincial People’s Congress, paid a goodwill visit to Sierra Leone and Cameroon in early December 2005. In Sierra Leone Vice President Solomon Ekuma Berewa, President of the Parliament Edmond Cowan, and Vice Foreign Minister Mohamed Kamara, and in

  14. Leadership Style: School Perspective in Cameroon

    OpenAIRE

    Asan Vernyuy Wirba

    2015-01-01

    This paper examines leadership styles of secondary school principals in Cameroon, in terms of transformational, transactional, and laissez-faire leadership styles. This paper discusses the leadership styles in Cameroon and puts forward ideas for continuous improvement. A qualitative approach, using a semistructured interview, was adopted. It was conducted on ten principals, ten teachers, and ten students. Majority of respondents from schools described their principals as transformational lea...

  15. Trace metals in water and fish (Unga species, Pungu maclareni, catfish Clarias maclareni) from Lake Barombi Mbo, Cameroon

    OpenAIRE

    Sone, Brice Nkwelle

    2012-01-01

    Lake Barombi Mbo is an isolated oligotrophic lake situated in the volcanic range of West Cameroon and home to several endangered endemic cichlids. A fieldwork was carried out at the lake where water and fish samples were collected as part of an investigation. The aim of this study was to investigate (i) whether studied trace metals were present at levels exceeding ambient water criteria, (ii) link uptake of trace metals in gills and liver of fish to water chemistry, (iii) ac...

  16. Catastrophic volcanism

    Science.gov (United States)

    Lipman, Peter W.

    1988-01-01

    Since primitive times, catastrophes due to volcanic activity have been vivid in the mind of man, who knew that his activities in many parts of the world were threatened by lava flows, mudflows, and ash falls. Within the present century, increasingly complex interactions between volcanism and the environment, on scales not previously experienced historically, have been detected or suspected from geologic observations. These include enormous hot pyroclastic flows associated with collapse at source calderas and fed by eruption columns that reached the stratosphere, relations between huge flood basalt eruptions at hotspots and the rifting of continents, devastating laterally-directed volcanic blasts and pyroclastic surges, great volcanic-generated tsunamis, climate modification from volcanic release of ash and sulfur aerosols into the upper atmosphere, modification of ocean circulation by volcanic constructs and attendent climatic implications, global pulsations in intensity of volcanic activity, and perhaps triggering of some intense terrestrial volcanism by planetary impacts. Complex feedback between volcanic activity and additional seemingly unrelated terrestrial processes likely remains unrecognized. Only recently has it become possible to begin to evaluate the degree to which such large-scale volcanic processes may have been important in triggering or modulating the tempo of faunal extinctions and other evolutionary events. In this overview, such processes are examined from the viewpoint of a field volcanologist, rather than as a previous participant in controversies concerning the interrelations between extinctions, impacts, and volcanism.

  17. International Uranium Resources Evaluation Project (IUREP) orientation phase mission report: Cameroon. Draft

    International Nuclear Information System (INIS)

    Geology Branch with mapping and exploration services. Most of CAMEROON is underlain by Precambrian granites , anatexites, migmatites, gneisses, and schists. The NTEM complex in the south is Archean age. Most other areas are probably Lower Proterozoic, with some Middle Proterozoic inliers of the LOM, POLI, and MBALMAYO-BENGBIS, and the DJA series in the southeast. The DJA tillite is probably Upper Proterozoic. There are small remnant basins of Paleozoic volcanics, and larger basins and grabens of Middle-Upper Cretaceous. Tertiary rocks are present in the Coastal basins and the southeast. The Lake Chad depression is covered with Quaternary sands. All of the older rocks except the NTEM complex and the DJA series are within the Panafrican Mobile Belt. The border faults of the Cretaceous BENOUE graben are throughgoing crustal features. Tertiary intrusives and plateau basalts are found along the 'LINE OF CAMEROON', and volcanism has continued to present. Uranium exploration from 1950 to present has produced mostly negative results. Only one important prospect has been found at GOBLE-KITONGO, and has been the subject of repeated exploration from 195 8 to present. An enriched zone in syenite at LOLODORF is also under investigation. Anomalies on an airborne survey of the DJA series are being checked for mineralization similar to the FRANCEVILLIAN of GABON. Total expenditures that may be assigned to uranium are on the order of $10 million (U.S.). There are no uranium ore reserves or reasonably assured resources in CAMEROON. Speculative resources of 10,000 tonnes have been assigned to the LOLODORT syenite, and 5000 tonnes to the GOBLE-KITONGO prospect and Paleozoic volcanics at $130/kg. (U.S.). Favorable areas are the DJA series, syenites of the Panafrican granite and 'granites ultimes', Mesozoic-Cenozoic basins (especially DOUALA), LOM and MBALMAYO-BENGBIS series, POLI-MAROUA, and Lower Proterozoic/Archean gneiss and granite. Recommendations have been made for topical studies of

  18. Gazing into the Mirror : Operational Internal Control in Cameroon Customs

    OpenAIRE

    Libom, Minette Li Likeng; Cantens, Thomas; Bilangna, Samson

    2009-01-01

    Cameroon is a model example of a developing country facing the challenges of trade facilitation, in light of its geographic location within Central Africa. Close to 20 percent of its customs revenues are used to finance the national budget. Cameroon's customs administration therefore plays a critical role in its economy. This paper presents the modernization process launched in Cameroon cu...

  19. Gas bursts from cameroon crater lakes: a new natural hazard.

    Science.gov (United States)

    Sigurdsson, H

    1988-06-01

    Gas bursts from tropical crater lakes constitute a hitherto unrecognized natural hazard, which claimed 37 lives around Lake Monoun in 1984 and 1,746 lives in 1986 around Lake Nyos in Cameroon, west Africa. Studies of these events indicate that the lethal gas clouds were dominantly CO(2) which exsolved catastrophically from deep waters of the lakes, producing in the case of Lake Nyos a gas cloud of 1.94 times 10(6) tons CO(2) . Carbon-isotope data indicate a magmatic source of the carbon dioxide, but the geochemistry of deep water and gases does not support a sudden injection of volcanic gas from a deep source into the lakes. Rather, it is proposed that the gas bursts were preceded by gradual build-up of dissolved bicarbonate in deep waters, where anoxic conditions in enclosed and stagnant basins led to low pH and pCO(2) close to saturation. Steady input from the Earth's mantle to submerged mofettes or CO(2) -rich soda springs within the lakes is most likely the primary source of carbon dioxide. Lethal effects of the gas bursts are almost entirely due to CO(2) -induced asphyxia. A small percentage of victims awoke from coma one or two days after the event, but most died. Unusual skin lesions on about 5% of victims arose from the comatose state. It is shown that the mass of gas required to account for the lethal effects and observed gas clouds is an order of magnitude less than the potential gas yield from the lakes. In view of the lethal gas bursts from the small Cameroon lakes, the potential hazard of future gas bursts from other much larger density-stratified equatorial lakes must be seriously considered, particularly in Lake Kivu in east Africa, where methane and carbon dioxide gas content is higher by two to four orders of magnitude than that of the Cameroon lakes. A gas burst from Lake Kivu would form a carbon dioxide cloud up to 340 km(3) in volume and expansion of the exsolving gas from deep water to atmospheric pressure would correspond to an energy release

  20. Survey of tomato diseases in Cameroon

    Directory of Open Access Journals (Sweden)

    Fontem, DA.

    1993-01-01

    Full Text Available Tomato (Lycopersicon esculentum Mill. is the most widely cultivated field vegetable crop in Cameroon. On-farm surveys were undertaken from November 1988 to October 1991 to identify nursery and field diseases in major tomato producing areas of Cameroon, Damping-off and seedling blights were the main seedling diseases. Of the eleven diseases observed in the field, the most widely distributed and severe on the foliage and fruits were early (Alternaria solani and late (Phytophthora infestans blights. Late blight was the most severe disease in the wet season while early blight was most severe in the dry season. Nine pathogens were associated with various fruit rots. This study indicates the need for an identification of appropriate control methods for early and late blights of tomato in Cameroon.

  1. Country programme review Republic of Cameroon

    International Nuclear Information System (INIS)

    A multi-disciplinary country programme review and programming mission was undertaken to the Republic of Cameroon, from 21 to 25 June 1993. This report reflects the findings and recommendations of the mission and falls into four sections. The first section describes the country profile and includes information about its economy and its development plans and policies. The second reviews the Agency's past and present technical co-operation programmes in Cameroon. The third section deals with a sectoral programme and institutional review, and the fourth section presents possible future technical co-operation activities

  2. Two new butterfly species (Lepidoptera: Rhopalocera) from Mount Cameroon, Gulf of Guinea Highlands, Cameroon.

    Science.gov (United States)

    Sáfián, Szabolcs; Tropek, Robert

    2016-01-01

    A field survey of Mount Cameroon, South-West Province, Cameroon, revealed two butterfly species new to science. Lepidochrysops liberti sp. nov. (Lycaenidae) flies in the extensive mosaic of natural clearings in sub-montane forest above 1100 m a.s.l., whereas Ceratrichia fako sp. nov. (Hesperiidae) locally inhabits the forested narrow gullies in the same vegetation zone. Observations on the habitat and behaviour of both species are also presented. PMID:27515650

  3. The Reception of American Literature in Cameroon

    Science.gov (United States)

    Djockoua, Manyaka Toko

    2014-01-01

    In Cameroon, popular belief associates American literature with its country's economic and political greatness. Yet, if millions of Cameroonians show a growing enthusiasm for a visit to the US, just a few are interested in learning its literature. Using theories on the reading and teaching of literature, statistical data based on a questionnaire,…

  4. Marketing of Accommodation services : Case-Hotel Azam Cameroon

    OpenAIRE

    Youkam, Germaine

    2012-01-01

    Cameroon is Africa in miniature with a lot of tourist attractions owing to its geological and cultural diversity. Natural features include beaches, deserts, mountains, rainforests, and savannas. Accommodation services have been a grand phenomenon within the tourism industry in Cameroon. The accommodation sector has developed tremendously within the past decades. The objective of this research work was to find about out the marketing of accommodation services in Cameroon with Hotel Azam as...

  5. Origin and age of the Lake Nyos maar, Cameroon

    Science.gov (United States)

    Lockwood, J.P.; Rubin, M.

    1989-01-01

    Lake Nyos occupies a young maar crater in the Precambrian granitic terrane of northwest Cameroon. The lake is partly surrounded by poorly consolidated, ultramafic nodule-bearing pyroclastic surge deposits that were explosively ejected from the Nyos crater at the time of its formation. Radiocarbon dates show that the maar probably formed about 400 years ago. Field evidence suggests that carbon dioxide could have been the principal volatile involved in the formation of the Nyos maar, and that the role of water may have been minor. The formation of the Nyos maar was preceded by a brief period of effusive basaltic volcanism, but the maar itself may have largely formed by cold, 'dry' explosive processes. Carbon dioxide may still be trapped interstitially in a diatreme inferred to underlie Lake Nyos; its gradual release into the waters of Lake Nyos may have set the stage for the tragic gas-release event of August 21, 1986. Only young maar lakes such as Nyos may pose a danger of future lethal gas releases. ?? 1989.

  6. Sub-continental lithospheric mantle structure beneath the Adamawa plateau inferred from the petrology of ultramafic xenoliths from Ngaoundéré (Adamawa plateau, Cameroon, Central Africa)

    Science.gov (United States)

    Nkouandou, Oumarou F.; Bardintzeff, Jacques-Marie; Fagny, Aminatou M.

    2015-11-01

    Ultramafic xenoliths (lherzolite, harzburgite and olivine websterite) have been discovered in basanites close to Ngaoundéré in Adamawa plateau. Xenoliths exhibit protogranular texture (lherzolite and olivine websterite) or porphyroclastic texture (harzburgite). They are composed of olivine Fo89-90, orthopyroxene, clinopyroxene and spinel. According to geothermometers, lherzolites have been equilibrated at 880-1060 °C; equilibrium temperatures of harzburgite are rather higher (880-1160 °C), while those of olivine websterite are bracketed between 820 and 1010 °C. The corresponding pressures are 1.8-1.9 GPa, 0.8-1.0 GPa and 1.9-2.5 GPa, respectively, which suggests that xenoliths have been sampled respectively at depths of 59-63 km, 26-33 km and 63-83 km. Texture and chemical compositional variations of xenoliths with temperature, pressure and depth on regional scale may be ascribed to the complex history undergone by the sub-continental mantle beneath the Adamawa plateau during its evolution. This may involve a limited asthenosphere uprise, concomitantly with plastic deformation and partial melting due to adiabatic decompression processes. Chemical compositional heterogeneities are also proposed in the sub-continental lithospheric mantle under the Adamawa plateau, as previously suggested for the whole Cameroon Volcanic Line.

  7. Evidences for a volcanic province in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Sudhakar, M.

    Based on various lines of evidence such as the widespread occurrence of basalts, pumice, volcanic glass shards and their transformational products (zeolites, palagonites, and smectite-rich sediments), we suggest the presence of a volcanic province...

  8. State formation, religion, and land tenure in Cameroon

    NARCIS (Netherlands)

    Schilder, K.; African Studies Centre, Leiden

    1988-01-01

    The purpose of this analytical bibliography is to provide an overview of the recently published social science literature on State formation, religion, and land tenure in Cameroon. The 800 entries have been arranged under the following subject headings: The Cameroon State (nation building, political

  9. An approach for the evaluation of rural governance in Cameroon: are community forests really forests for the communities?

    Directory of Open Access Journals (Sweden)

    Hilaire NKENGFACK

    2009-01-01

    Full Text Available The aim of this paper is to evaluate the contribution of the traditionalexploitation of timber, in a community framework, to the respect of governanceprinciples in actions for the fight against poverty in some rural communities inCameroon. In 1990, the government of Cameroon adopted laws on the freedomof association that authorised teaming up for the search of possibilities for abetter economic welfare of populations. It is in line with this that in 1994, a newforest law which authorises willing communities to organise themselves andrequest the government to grant them a portion of the national forest of thepublic domain to be managed by them and for their personal interest. Also, andwith the help of the international community, Cameroon elaborated in 1998 itsfirst poverty reduction strategy paper that encouraged amongst others,community actions in the search of solutions to the economic crisis that strokethe country. Through the application of a logit model to the responses collectedthrough a survey carried out on a sample of 200 individuals of the East regionof Cameroon, it was noticed that timber exploitation in a community frameworkdoes not necessarily lead to the strengthening of the links of belonging to acommon community, and to the equitable redistribution of revenues from theexploitation of the community forest.

  10. The Attitudes of Anglophone and Francophone Cameroonians towards Cameroon English as a Model of English Language Teaching and Learning in Cameroon

    Science.gov (United States)

    Atechi, Samuel; Angwah, Julius

    2016-01-01

    Teachers of English in Cameroon are proficient speakers of Cameroon English and their non-native status militates against their usage of Standard British English in the English language classrooms. This makes the attainment of British English thorny and perhaps impossible in Cameroon. Standing on that premise, we were motivated to find out…

  11. Structural adjustment, women, and agriculture in Cameroon.

    Science.gov (United States)

    Fonchingong, C

    1999-11-01

    This article assesses the impact of economic structural programs on the agricultural activities of women's groups in Cameroon, and explores women's ways of coping with the reduction in individual and family income and the loss of public services. It examines the role of 25 women's groups in both rural and urban areas of Cameroon's northwest and southwest provinces in a study conducted from April to June 1999. Economic structural adjustment caused a tremendous increase in the workload of women that are farming usually in lots distant from their homes that yield poor returns. Land for food-crop cultivation has become increasingly scarce, and inputs have become substantially unaffordable. Income generated from the sale of crops is inadequate to supply the economic and social needs of the family. Moreover, the burden of their work has increased as they cope with housework, child-care, and food production, in addition to an expanded participation in paid employment. Moreover, women spend longer working hours than men, meeting both household responsibilities and their outside work. Women have devised strategies to cope with this economic crisis, but they need organizations that will support them with the important resources to be able to operate. Rural women seem to be coping better than urban women cope. In extreme cases, some women in urban areas resort to prostitution to cope with life in this crisis setting. PMID:12349481

  12. Clinical waste incinerators in Cameroon--a case study

    DEFF Research Database (Denmark)

    Mochungong, Peter Ikome Kuwoh; Gulis, Gabriel; Sodemann, Morten

    2012-01-01

    Incinerators are widely used to treat clinical waste in Cameroon's Northwest Region. These incinerators cause public apprehension owing to purported risks to operators, communities and the environment. This article aims to summarize findings from an April 2008 case study.......Incinerators are widely used to treat clinical waste in Cameroon's Northwest Region. These incinerators cause public apprehension owing to purported risks to operators, communities and the environment. This article aims to summarize findings from an April 2008 case study....

  13. Mapping of Bancroftian Filariasis in Cameroon: Prospects for Elimination

    OpenAIRE

    Nana-Djeunga, Hugues C.; Tchatchueng-Mbougua, Jules B.; Bopda, Jean; Mbickmen-Tchana, Steve; Elong-Kana, Nathalie; Nnomzo’o, Etienne; Akame, Julie; Tarini, Ann; Zhang, Yaobi; Njiokou, Flobert; Kamgno, Joseph

    2015-01-01

    Background Lymphatic filariasis (LF) is one of the most debilitating neglected tropical diseases (NTDs). It still presents as an important public health problem in many countries in the tropics. In Cameroon, where many NTDs are endemic, only scant data describing the situation regarding LF epidemiology was available. The aim of this study was to describe the current situation regarding LF infection in Cameroon, and to map this infection and accurately delineate areas where mass drug administr...

  14. Local governance in disaster risk reduction in Cameroon

    OpenAIRE

    Gaston, Buh-Wung; Tongwa, Aka F; Burnley, Clementine

    2012-01-01

    At the 2005 World Conference on Disaster Risk Reduction held in Hyogo, Japan, 168 countries including Cameroon adopted the Hyogo Framework for Action, committing to take action to reduce human and socio-economic disaster losses. Geotechnology, Environmental Assessment and Disaster Risk Reduction was commissioned by the Global Network of Civil Society Organisations for Disaster Risk Reduction as the coordinating organisation in Cameroon to evaluate progress in implementation of the framework f...

  15. Coverage and costs of childhood immunizations in Cameroon.

    OpenAIRE

    Waters, Hugh R.; Dougherty, Leanne; Tegang, Simon-Pierre; Van Tran, Nhan; Wiysonge, Charles Shey; Long, Kanya; Wolfe, Nathan D.; Donald S Burke

    2004-01-01

    OBJECTIVE: To quantify the association between household-level and provider-level determinants and childhood immunization rates in Cameroon while also calculating the cost of childhood immunizations. METHODS: This study uses multilevel regression analysis to calculate these relationships. The 1998 Cameroon Demographic and Health Survey and the 2000 Multiple Indicator Cluster Survey are the main sources of household-level data. These surveys are supplemented by data from a 2002 survey of healt...

  16. Economic Impact of Ecotourism in Mount Cameroon Region

    OpenAIRE

    Njumba, Oscar

    2012-01-01

    Ecotourism activities are growing in popularity around the world and generating considerable financial effects to the local population. The definitions of this phenomenon are still evolving, but generally include references to travel to natural areas and local conservation benefits. The purpose of this study was to estimate the economic impact of this business to the youths and the local communities in the Mount Cameroon region under a Non Governmental Organization (NGO) called Mount Cameroon...

  17. Synopsis of volcanic stratigraphy

    Science.gov (United States)

    Hammond, P. E.

    1974-01-01

    Volcanic stratigraphic units are mappable layered units composed of volcanic rocks that are formed on land (subaerially) or under water (subaqueously) by volcanic processes. At least ten different types of volcanic stratigraphic units are recognized. The characteristics for each are discussed briefly and some typical examples are illustrated by diagrams to show their salient features.

  18. 76 FR 1660 - Culturally Significant Objects Imported for Exhibition Determinations: “Art in Cameroon...

    Science.gov (United States)

    2011-01-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Art in Cameroon: Sculptural... ``Art in Cameroon: Sculptural Dialogues,'' imported from abroad for temporary exhibition within...

  19. Biodiversity conservation, ecotourism and rural liverlihoods in protected areas. Case study : the Mount Cameroon National Park

    OpenAIRE

    Nkengfack, Susan Nkendem

    2012-01-01

    This study was carried out in the South West Province of Cameroon, specifically in the Mount Cameroon Region which encompasses the Mount Cameroon National park and its surrounding villages. The aim of the study was to assess how ecotourism is used as a tool to conserve the rich biodiversity of this area while improving the livelihoods of the local people and fostering development in the local communities. Focus was on the activities of the Mount Cameroon Inter-communal Ecotourism Board (Mt...

  20. Lead exposure from aluminum cookware in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Weidenhamer, Jeffrey D.; Kobunski, Peter A. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Kuepouo, Gilbert [Research and Education Centre for Development (CREPD), Yaounde (Cameroon); Corbin, Rebecca W. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Gottesfeld, Perry, E-mail: pgottesfeld@okinternational.org [Occupational Knowledge International, San Francisco, CA (United States)

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  1. Cameroon: A Country Guide Series Report from the AACRAO-AID Project.

    Science.gov (United States)

    Saidi, Jasmin

    This report on the educational system of Cameroon contains information for university admissions officers and registrars in the United States on the credentials and other documentation that would be minimally required for student entry from Cameroon to specified levels of study in the United States. In Cameroon French and English languages share…

  2. Language Practices and Religious Rites in the Full Gospel Mission Cameroon

    Science.gov (United States)

    Kouega, Jean-Paul

    2016-01-01

    This paper deals with language practices in one Pentecostal church in Cameroon, i.e. the Full Gospel Mission Cameroon (FGMC). The data are produced by some 80 pastors, church officials, choir leaders and congregants, and the settings are some 20 churches located in two anglophone regions and two francophone regions of Cameroon. The instruments…

  3. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  4. Deficiencies in pastoral care with prisoners in Cameroon

    Directory of Open Access Journals (Sweden)

    Abraham K. Akih

    2012-01-01

    Full Text Available Cameroon celebrated fifty years of independence from colonial rule on 20 May 2010. Major problems facing the nation are economic, social and political crises and the appalling condition of its prisons. This article focuses on pastoral care with prisoners in Cameroon. Most churches in Cameroon have no pastoral care programme for prisoners. The churches in general are not yet committed to this kind of work. The article argues that changes and reform of the penitential system will be difficult if not impossible without collaboration with other institutions and resources, which include the different faith communities and faith based organisations. The focus should be on the care and well-being of those within its walls if successful rehabilitation is to take place. Spiritual care will contribute to the general well-being of prisoners. The article gives a broad overview of the situation of prisons and prisoners in Cameroon and presents a pastoral care approach that could contribute to the overall improvement of the lives of people in Cameroon prisons.

  5. State-space approach to evaluate spatial variability of field measured soil water status along a line transect in a volcanic-vesuvian soil

    Directory of Open Access Journals (Sweden)

    A. Comegna

    2010-12-01

    Full Text Available Unsaturated hydraulic properties and their spatial variability today are analyzed in order to use properly mathematical models developed to simulate flow of the water and solute movement at the field-scale soils. Many studies have shown that observations of soil hydraulic properties should not be considered purely random, given that they possess a structure which may be described by means of stochastic processes. The techniques used for analyzing such a structure have essentially been based either on the theory of regionalized variables or to a lesser extent, on the analysis of time series. This work attempts to use the time-series approach mentioned above by means of a study of pressure head h and water content θ which characterize soil water status, in the space-time domain. The data of the analyses were recorded in the open field during a controlled drainage process, evaporation being prevented, along a 50 m transect in a volcanic Vesuvian soil. The isotropic hypothesis is empirical proved and then the autocorrelation ACF and the partial autocorrelation functions PACF were used to identify and estimate the ARMA(1,1 statistical model for the analyzed series and the AR(1 for the extracted signal. Relations with a state-space model are investigated, and a bivariate AR(1 model fitted. The simultaneous relations between θ and h are considered and estimated. The results are of value for sampling strategies and they should incite to a larger use of time and space series analysis.

  6. Best practice guidelines for stroke in Cameroon: An innovative and participatory knowledge translation project

    Directory of Open Access Journals (Sweden)

    Lynn Cockburn

    2014-04-01

    Full Text Available Background: Although the adherence to stroke guidelines in high-income countries has been shown to be associated with improved patient outcomes, the research, development and implementation of rehabilitation related guidelines in African countries is lacking.Objectives: The purpose of this article is to describe how a group of front-line practitioners collaborated with academics and students to develop best practice guidelines (BPG for the management and rehabilitation of stroke in adult patients in Cameroon.Method: A working group was established and adapted internationally recognised processes for the development of best practice guidelines. The group determined the scope of the guidelines, documented current practices, and critically appraised evidence to develop guidelines relevant to the Cameroon context.Results: The primary result of this project is best practice guidelines which provided an overview of the provision of stroke rehabilitation services in the region, and made 83 practice recommendations to improve these services. We also report on the successes and challenges encountered during the process, and the working group’s recommendations aimed at encouraging others to consider similar projects.Conclusion: This project demonstrated that there is interest and capacity for improving stroke rehabilitation practices and for stroke guideline development in Africa.

  7. Analytical Model of Underground Train Induced Vibrations on Nearby Building Structures in Cameroon: Assessment and Prediction

    Directory of Open Access Journals (Sweden)

    Lezin Seba MINSILI

    2013-11-01

    Full Text Available The purpose of this research paper was to assess and predict the effect of vibrations induced by an underground railway on nearby-existing buildings prior to the construction of projected new railway lines of the National Railway Master Plan of Cameroon and after upgrading of the railway conceded to CAMRAIL linking the two most densely populated cities of Cameroon: Douala and Yaoundé. With the source-transmitter-receiver mathematical model as the train-soil-structure interaction model, taking into account sub-model parameters such as type of the train-railway system, typical geotechnical conditions of the ground and the sensitivity of the nearby buildings, the analysis is carried out over the entire system using the dynamic finite element method in the time domain. This subdivision of the model is a powerful tool that allows to consider different alternatives of sub-models with different characteristics, and thus to determine any critical excessive vibration impact. Based on semi-empirical analytical results obtained from presented models, the present work assesses and predicts characteristics of traffic-induced vibrations as a function of time duration, intensity and vehicle speed, as well as their influence on buildings at different levels.

  8. Internet adoption and usage patterns in Africa: Evidence from Cameroon

    OpenAIRE

    Penard, Thierry; Poussing, Nicolas; MUKOKO Blaise; TAMOKWE Georges Bertrand

    2013-01-01

    The objective of this paper is to understand what factors stimulate or hinder the adoption and usage of the Internet in Africa. We adopt a micro-econometric approach and use household survey data from Cameroon. Our results show that Internet users in Cameroon tend to be young, educated and in employment. The probability of using the Internet is also higher for male, as well as for English-speaking and computer savvy individuals. Moreover, Internet users are more likely to have family abroad. ...

  9. Assessing the detection, reporting and investigation of adverse events in clinical trial protocols implemented in Cameroon: a documentary review of clinical trial protocols

    OpenAIRE

    Ebile, Akoh Walter; Ateudjieu, Jerome; Yakum, Martin Ndinakie; Djuidje, Marceline Ngounoue; Watcho, Pierre

    2015-01-01

    Background International guidelines recommend ethical and scientific quality standards for managing and reporting adverse events occurring during clinical trials to competent research ethics committees and regulatory authorities. The purpose of this study was to determine whether clinical trial protocols in Cameroon are developed in line with national requirements and international guidelines as far as detecting, reporting and investigating of adverse events is concerned. Methods It was a doc...

  10. The unfortunate sufferer: discursive dynamics around pregnancy loss in Cameroon

    NARCIS (Netherlands)

    E. van der Sijpt

    2013-01-01

    Pregnancy losses are ambiguous affairs in East Cameroon. Childbearing is not always people's primary aim within their fragile sexual and marital relationships, and it is often unclear to outsiders whether a pregnancy interruption is intended or unintended. Drawing on 15 months of fieldwork, I explor

  11. REDD+ policy strategy in Cameroon: Actors, institutions and governance

    NARCIS (Netherlands)

    Somorin, O.A.; Visseren-Hamakers, I.J.; Arts, B.J.M.; Sonwa, D.J.; Tiani, A.

    2014-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is receiving increasing political and scientific attention as a climate change mitigation approach. The government of Cameroon has expressed an interest in participating in REDD+, and national deliberation on a policy strategy has

  12. Anglophone university students and anglophone nationalist struggles in Cameroon

    NARCIS (Netherlands)

    Konings, P.J.J.

    2005-01-01

    The importance of student politics in Africa during economic and political liberalization cannot be underestimated. However, this study of anglophone students in Cameroon cautions against treating students as a homogeneous group. It shows that although anglophone students today feel even more margin

  13. Does malaria epidemiology project Cameroon as `Africa in miniature'?

    Indian Academy of Sciences (India)

    Huguette Gaelle Ngassa Mbenda; Gauri Awasthi; Poonam K Singh; Inocent Gouado; Aparup Das

    2014-09-01

    Cameroon, a west-central African country with a ∼20 million population, is commonly regarded as ‘Africa in miniature’ due to the extensive biological and cultural diversities of whole Africa being present in a single-country setting. This country is inhabited by ancestral human lineages in unique eco-climatic conditions and diverse topography. Over 90% Cameroonians are at risk of malaria infection, and ∼41% have at least one episode of malaria each year. Historically, the rate of malaria infection in Cameroon has fluctuated over the years; the number of cases was about 2 million in 2010 and 2011. The Cameroonian malaria control programme faces an uphill task due to high prevalence of multidrug-resistant parasites and insecticide-resistant malaria vectors. Above all, continued human migration from the rural to urban areas as well as population exchange with adjoining countries, high rate of ecological instabilities caused by deforestation, poor housing, lack of proper sanitation and drainage system might have resulted in the recent increase in incidences of malaria and other vector-borne diseases in Cameroon. The available data on eco-environmental variability and intricate malaria epidemiology in Cameroon reflect the situation in the whole of Africa, and warrant the need for in-depth study by using modern surveillance tools for meaningful basic understanding of the malaria triangle (host-parasite-vector-environment).

  14. Linguistic Interference in a Multilingual Setting: The Case of Cameroon

    Science.gov (United States)

    Julius, Nashipu

    2006-01-01

    Cameroon, a central African state is one of the few countries in the world where, in addition to a very rich linguistically diverse landscape (a little below 300 identified indigenous languages) there is English and French (all vestiges of colonial legacy) used as official languages. Coupled with this, there is pidgin English which plays the role…

  15. Aspects of a Grammar of Makary Kotoko (Chadic, Cameroon)

    Science.gov (United States)

    Allison, Sean David

    2012-01-01

    Makary Kotoko (MK), a Central Chadic B language, is spoken in the north of Cameroon just south of Lake Chad. Published works on MK to date include about a dozen articles on different aspects of the grammar of the language, primarily by H. Tourneux. The present work, which is based on a substantial corpus of recorded texts, is a systematic…

  16. [Return for HIV test results after voluntary screening in Cameroon].

    Science.gov (United States)

    2016-01-01

    The results of this study indicate that individuals who voluntarily undergo an HIV test in PVTCCs of the Douala district hospitals in Cameroon perceived real advantages and very few disadvantages and barriers to know their HIV status. Particular attention should be given to organizational factors that may be responsible for failure to return for HIV test results and post-test counselling.. PMID:27531439

  17. Floodplain rehabilitation in North Cameroon: impact on vegetation dynamics

    NARCIS (Netherlands)

    Scholte, P.; Kirda, P.; Adam, S.; Kadiri, B.

    2000-01-01

    Since the construction in 1979 of a dam in the Logone floodplain in the Sahelo-Sudanian zone of Cameroon, annual inundations have decreased, reducing perennial vegetation as important grazing source for nomadic herds and wildlife during the dry season. Presently, possibilities exist to release exces

  18. Local vegetables in Cameroon: Corchorus species used as a vegetable.

    NARCIS (Netherlands)

    Westphal-Stevels, J.M.C.

    1986-01-01

    An agro-botanical study of local vegetables in Cameroon is in preparation, including the taxonomy, identity, morphology, agronomy and nutritional value of about 70 species. Corchorus olitorius L. and other edible species of the genus Corchorus L. (Tiliaceae) are part of this study. The wide variatio

  19. Cattle ticks in Cameroon: is Rhipicephalus (Boophilus) microplus absent in Cameroon and the Central African region?

    Science.gov (United States)

    Awa, D N; Adakal, H; Luogbou, N D D; Wachong, K H; Leinyuy, I; Achukwi, M D

    2015-03-01

    In most parts of the world, ticks are rapidly developing resistance to commonly used acaricides thus rendering control difficult. This constraint is further compounded by the introduction of new species in areas where they did not exist before. Such is the case with the introduction into and rapid spread of Rhipicephalus (Boophilus) microplus in some countries of West Africa. With the looming threat of its further spread in the region, the objective of the present study was to update knowledge on cattle ticks in Cameroon. Among 19,189 ticks collected monthly from 60 animals in 5 herds from March 2012 to February 2013, Rh. (B.) decoloratus was the most abundant species with a relative prevalence of 62.2%, followed by Amblyomma variegatum (28.4%), Rh. (B.) annulatus (0.2%), Rh. (B.) geigyi (0.03%), other Rhipicephalus spp. (8.4%) and Hyalomma spp. (0.3%). Rh. (B.) decoloratus and A. variegatum were also the most widely distributed in space. Infestation rate was generally high, with average tick count/animal of about 80 during peak periods. Tick distribution and abundance in the different sites was as varied as the underlying factors, among which the most important were management systems and climatic factors. The effects of rainfall and temperature were confounded by other factors and difficult to evaluate. However, it appears tick development depends among other factors, on a humidity threshold, above which there is not much more effect. Rh. microplus was not found during this study, but more extensive tick collections have to be done to confirm this. In conclusion, cattle tick infestation in Cameroon remains an important cause for concern. Farmers need assistance in the use and management of acaricides in order to increase their efficiency and reduce the development of resistance. Although Rh. microplus was not found, its introduction from other West African countries is imminent if adequate measures, especially in the control and limitation of animal movements

  20. Early warning indicators for HIV drug resistance in Cameroon during the year 2010.

    Directory of Open Access Journals (Sweden)

    Serge C Billong

    Full Text Available BACKGROUND: Rapid scale-up of antiretroviral therapy (ART in resource-limited settings is accompanied with an increasing risk of HIV drug resistance (HIVDR, which in turn could compromise the performance of national ART rollout programme. In order to sustain the effectiveness of ART in a resource-limited country like Cameroon, HIVDR early warning indicators (EWI may provide relevant corrective measures to support the control and therapeutic management of AIDS. METHODS: A retrospective study was conducted in 2010 among 40 ART sites (12 Approved Treatment Centers and 28 Management Units distributed over the 10 regions of Cameroon. Five standardized EWIs were selected for the evaluation using data from January through December, among which: (1 Good ARV prescribing practices: target = 100%; (2 Patient lost to follow-up: target ≤ 20%; (3 Patient retention on first line ART: target ≥ 70%; (4 On-time drug pick-up: target ≥ 90%; (5 ARV drug supply continuity: target = 100%. Analysis was performed using a Data Quality Assessment tool, following WHO protocol. RESULTS: THE NUMBER OF SITES ATTAINING THE REQUIRED PERFORMANCE ARE: 90% (36/40 for EWI(1, 20% (8/40 for EWI(2; 20% (8/40 for EWI(3; 0% (0/37 for EWI(4; and 45% (17/38 for EWI 5. ARV prescribing practices were in conformity with the national guidelines in almost all the sites, whereas patient adherence to ART (EWI(2, EWI(3, and EWI(4 was very low. A high rate of patients was lost-to-follow-up and others failing first line ART before 12 months of initiation. Discontinuity in drug supply observed in about half of the sites may negatively impact ARV prescription and patient adherence. These poor ART performances may also be due to low number of trained staff and community disengagement. CONCLUSIONS: The poor performance of the national ART programme, due to patient non-adherence and drug stock outs, requires corrective measures to limit risks of HIVDR emergence in Cameroon.

  1. Cassava Processing and Marketing by Rural Women in the Central Region of Cameroon

    OpenAIRE

    SHIOYA, Akiyo

    2013-01-01

    This study examines the development of rural women's commercial activities in Central Cameroon, particularly the Department of Lekié, which is adjacent to Yaoundé, the capital of Cameroon. I focused on cassava processing technologies and the sale of cassavabased processed foods undertaken by women in a suburban farming village. Cassava is one of the main staple foods in central Cameroon, including in urban areas. One of its characteristics is that it keeps for a long period in the ground but ...

  2. Community pico and micro hydropower for rural electrification: experiences from the mountain regions of Cameroon

    OpenAIRE

    Stefano Mandelli; Emanuela Colombo; Jerome Mungwe

    2016-01-01

    Less than 15% of rural areas of Cameroon have access to grid electricity. Only 53% of the population has access to grid electricity. Notwithstanding, Cameroon has a huge hydropower potential which could be harnessed. Mini grids, powered by pico and micro hydropower plants, are a relatively new rural electrification strategy in Cameroon. Several of such mini grids have been realized in the mountain regions of the country. Some of these systems have been more successful than others. This paper ...

  3. Entrepreneurship Development in a Local Context: Evidence from Entrepreneurs in the Eastern Region of Cameroon

    OpenAIRE

    2015-01-01

    In Cameroon, entrepreneurial activities are developed from two main cities namely; Douala and Yaound¨¦. Therefore researches on entrepreneurship development in Cameroon are based on entrepreneurs from these main cities, while other regions entrepreneurial activities are not considered as a target for entrepreneurship analysis. This paper analyses entrepreneurial activities in Eastern Cameroon that has a lowest level of enterprise creation that is in contrast to the abundant natural resources ...

  4. Geoheritage at the Equator: Selected Geosites of São Tomé Island (Cameron Line, Central Africa

    Directory of Open Access Journals (Sweden)

    Maria Helena Henriques

    2015-01-01

    Full Text Available This work presents, for the first time, an overview of the rich geodiversity outcropping in the São Tomé island, one of the two islands that make up the archipelago of São Tomé and Príncipe, the second smallest state of Africa in area. Located at the equator, in the alignment known as the “Cameroon Volcanic Line”, this archipelago represents a privileged area for the comparative study between oceanic and continental alkaline volcanism, and therefore between the subcontinental and suboceanic mantle. Ten geosites of São Tomé island were selected, described and evaluated on the basis of their geoheritage value and using a qualitative system of classification, which integrates both the meaning attributed to the objects by scientific communities and the public understanding of such meanings related to its social use. The selected geosites display different heritage values (documental, scenic, symbolic, iconographic and indicial potentially usable for different purposes, namely scientific and educational, but mostly tourism. Geotourism can play a key role in the promotion of sustainable development in the Democratic Republic of São Tomé and Príncipe, and the geosites here described are likely to ground a geo-itinerary on this “pearl” of the Cameron Line.

  5. Teachers’ approaches to language classroom assessment in Cameroon primary schools

    Directory of Open Access Journals (Sweden)

    Achu Charles Tante

    2013-10-01

    Full Text Available Assessment has a huge impact on ESL primary pupils, in part, because on the curriculum English is both a subject and also a language of learning all the other subjects. For children still acquiring L1 it is daunting sometimes to be expected to understand concepts in L2. It may be difficult then to gather information to make an impartial judgement with regards to a pupil’s language level. This study is a preliminary inquiry that attempts to find out teachers’ approaches to classroom assessment in Cameroon primary schools. Using a qualitative open-ended question the researcher finds out three main categories of assessment approaches used by teachers. From the categories extrapolations on possible assumptions that guide teachers’ choices of assessment procedures are described and suggested for future study. Keywords Classroom assessment approach, Cameroon, scheme of work, ESL/EFL, Young Learners 

  6. Anglophone university students and anglophone nationalist struggles in Cameroon

    OpenAIRE

    Konings, P.J.J.

    2005-01-01

    The importance of student politics in Africa during economic and political liberalization cannot be underestimated. However, this study of anglophone students in Cameroon cautions against treating students as a homogeneous group. It shows that although anglophone students today feel even more marginalized than their francophone counterparts, they have actually displayed a rather ambivalent attitude towards the francophone-dominated State. The author first describes the development of anglopho...

  7. Evaluation of health policies : an economic analysis applied to Cameroon

    OpenAIRE

    Nkwenkeu, Sylvain F.

    2014-01-01

    In Cameroon, the sequence of reforms in the health sector has reinforced an ideological wavering between two opposing currents: a socio-universal that promotes equity, and a neoliberal, which militates for greater economic efficiency of existing systems. Articulating two concerns which are, the worsening of health inequalities as consequence of policy choices made on the efficacy of services without taking into account factors that support the demand, and the form of organization of the healt...

  8. Impact of agribusiness labour on the child education in Cameroon

    Directory of Open Access Journals (Sweden)

    Tiwang N Gildas

    2015-12-01

    Full Text Available This paper aimed to assess the involvement of child labour in agribusinesses as well as the schooling pattern of children involved in these agribusinesses in Cameroon. For this study, some descriptive statistics and cross tabulations were computed using SPSS.20 and stata 13 software packages. The population of this study was made up of 51,190 individuals of both sexes that were concerned by the third Cameroon National Household Survey. The sample drawn from this population was constituted of individuals of age 5-17 years old, making a total of 17,550 children. The main results of this study revealed that agribusiness child labour was present everywhere in Cameroon and by both boys and girls. Children of all ages of the sample were concerned by the phenomenon and their level of education was essentially the primary. The impact of agribusiness child labour on education was positive because it helped the working and schooling children to provide means to finance their education and other needs. On the other hand, it has a negative impact on education because some children went for these jobs and finally stayed there and did not return back to school.

  9. Particle Choices and Collocation in Cameroon English Phrasal Verbs

    Directory of Open Access Journals (Sweden)

    Napoleon Epoge

    2016-02-01

    Full Text Available The meaning of some phrasal verbs can be guessed from the meanings of the parts (to sit down = sit + down, run after = run + after and the meaning of some others have to be learned (to put up (a visitor = accommodate, to hold up = cause delay or try to rob someone due to their syntactic and semantic complexities. In this regard, the syntactic and semantic properties are expected to be the same in every English speaking context. Thus, this paper aims to explore the input-oriented syntactic and semantic properties of phrasal verbs in Cameroon English. Findings reveal that the syntactic property of some phrasal verbs undergoes innovative processes such as particle substitution (to round up a point, omission (to bite more than you can chew, and redundancy (to meet up with the requirements; while the semantic property undergoes the process of semantic extension (to came out with a pathetic story to justify ones absence from office; to come out with a wonderful strategy to curb corruption, and semantic shift (to put up with someone for one semester. This reveals that, in the New English context such as Cameroon, users resort to the domestication of the alien language as a functional and dominant paradigm to combat cultural imperialism and express new identity.Keywords: Cameroon English, collocation, particle, phrasal verb, semantics, syntax

  10. Dentofacial injuries in contact sports in Yaounde, Cameroon

    Directory of Open Access Journals (Sweden)

    M A Agbor

    2012-01-01

    Full Text Available Background: Dentofacial injuries constitute serious problems among competitive and recreational athletes, worldwide. Objective: To determine the prevalence of dentofacial injuries and related factors among individuals participating in contact sports in Yaoundé, Cameroon. Materials and Methods: This cross-sectional study among individuals participating in karate, judo, basketball, handball, football and wrestling in Yaoundé, Cameroon was conducted between January and April, 2012. Results: Of the 240 athletes interviewed, 115 and 89 of them reported bodily and dentofacial injuries giving 47.9% and 37.1% prevalence, respectively. The bodily injuries were limbs-(60.0%, chest-(23.5%, abdomen-(11.3% and neck- (5.2%. Mouth and face accounted for 52.8% and 37.1% of the dentofacial injuries, respectively. Other dentofacial injuries were teeth-(6.7% and mandible-(3.4%. Older athletes and years of participation were more likely to experience dentofacial injuries. Karate was the most common cause of dentofacial injuries followed by wrestling. The prevalence of the dentofacial injuries was similar among both genders and was equally prevalent during training and competition. The personal protective equipment use reduced the likelihood of dentofacial injuries among the athletes. Conclusion: The prevalence of dentofacial injuries were high while the personal protective equipment use was low among the individuals participating in contact sports in Yaoundé, Cameroon.

  11. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  12. Cryptoccocal meningitis in Yaoundé (Cameroon) HIV infected patients: Diagnosis, frequency and Cryptococcus neoformans isolates susceptibility study to fluconazole.

    Science.gov (United States)

    Kammalac Ngouana, T; Dongtsa, J; Kouanfack, C; Tonfack, C; Fomena, S; Mallié, M; Delaporte, E; Boyom, F-Fekam; Bertout, S

    2015-03-01

    Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Cameroon, and studied the antifungal susceptibility of isolated strains to fluconazole, used as first line treatment of the disease in Cameroon. Between December 2009 and July 2011, 146 cerebrospinal fluids obtained from HIV patients with suspicion of meningitis were analysed. The diagnosis procedure involved macroscopic and cyto-chemical analysis, India ink test, culture on Sabouraud chloramphenicol medium and antigen latex agglutination test. Antifungal susceptibility testing of isolated strains to fluconazole was done by the E-test(®) method. The diagnosis of cryptococcal meningitis gave 28.08% positive cases. Among these patients, 80% were at stages III and IV and 20% at stage I of the HIV infection, according to the WHO previous classification. Cyto-chemical analysis showed current findings in the case of cryptococcal meningitis. India ink test and latex agglutination test exhibited very high sensitivity and specificity (>94%). Fluconazole antifungal susceptibility testing gave MICs lower than 32μg/mL to 92.7% of isolated strains and MICs greater than this value to 7.3% of isolates. These results showed that cryptococcal meningitis remains a real problem among HIV infected patients in Yaoundé. The emergence of fluconazole reduced susceptibility strains is worrying. Nevertheless, efficacy of rapid detection tests is interesting because this will help in rapid diagnosis and treatment of patients.

  13. Volcanic evolution of the South Sandwich volcanic arc, South Atlantic, from multibeam bathymetry

    Science.gov (United States)

    Leat, Philip T.; Day, Simon J.; Tate, Alex J.; Martin, Tara J.; Owen, Matthew J.; Tappin, David R.

    2013-09-01

    New multibeam bathymetry data are presented for the South Sandwich intra-oceanic arc which occupies the small Sandwich plate in the South Atlantic, and is widely considered to be a simple end-member in the range of intra-oceanic arc types. The images show for the first time the distribution of submarine volcanic, tectonic and erosional-depositional features along the whole length of the 540 km long volcanic arc, allowing systematic investigation of along-arc variations. The data confirm that the volcanic arc has a simple structure composed of large volcanoes which form a well-defined volcanic front, but with three parallel cross-cutting seamount chains extending 38-60 km from near the volcanic front into the rear-arc. There is no evidence for intra-arc rifting or extinct volcanic lines. Topographic evidence for faulting is generally absent, except near the northern and southern plate boundaries. Most of the volcanic arc appears to be built on ocean crust formed at the associated back-arc spreading centre, as previously proposed from magnetic data, but the southern part of the arc appears to be underlain by older arc or continental crust whose west-facing rifted margin facing the back-arc basin is defined by the new bathymetry. The new survey shows nine main volcanic edifices along the volcanic front and ca. 20 main seamounts. The main volcanoes form largely glaciated islands with summits 3.0-3.5 km above base levels which are 2500-3000 m deep in the north and shallower at 2000-2500 m deep in the south. Some of the component seamounts are interpreted to have been active since the last glacial maximum, and so are approximately contemporaneous with the volcanic front volcanism. Seven calderas, all either submarine or ice-filled, have been identified: Adventure volcano, a newly discovered submarine volcanic front caldera volcano is described for the first time. All but one of the calderas are situated on summits of large volcanoes in the southern part of the arc, and

  14. Tropform, A decision support model for sustainable management of South-Cameroon's rain forest

    NARCIS (Netherlands)

    Eba'a Atyi, R.

    2000-01-01

    Natural forests play an important role in the economy of Cameroon, at both the national and local levels. Unfortunately, there is still a general sense that in Cameroon, like in most tropical countries, forests are not managed in a sustainable way. The poor forest management practices, which still p

  15. Teachers' Perceptions of Students with Special Education Needs in Cameroon Secondary Schools

    Science.gov (United States)

    Arrah, Rosemary Oneke; Swain, Kristine D.

    2014-01-01

    This study examined teachers' perceptions of including students with special education needs in Cameroon secondary schools. Teachers (N = 130) from five secondary government, denominational or lay private schools in Buea subdivision of Cameroon, Africa, completed a 26-item survey. The survey was analyzed using descriptive statistics, t-tests,…

  16. 78 FR 16029 - Waiver of Restriction on Assistance to the Central Government of Cameroon

    Science.gov (United States)

    2013-03-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Waiver of Restriction on Assistance to the Central Government of Cameroon Pursuant to Section 7031(b)(3) of... Section 7031(b)(1) of the Act with respect to Cameroon, and I hereby waive this restriction....

  17. Adaptation of Regional Representative Soil Project and Soil Judging for Cameroon

    Science.gov (United States)

    Che, Celestine Akuma

    2013-01-01

    Representative regional soils have agricultural, cultural, economic, environmental, and historical importance to Cameroon. Twenty seven regional representative soils have been identified in Cameroon. A set of laboratory exercises, assignments and exam questions have been developed utilizing the Regional Representative Soil Project (RRSP) that…

  18. 76 FR 61134 - Waiver of Restriction on Assistance to the Central Government of Cameroon

    Science.gov (United States)

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Waiver of Restriction on Assistance to the Central Government of Cameroon Pursuant to Section 7086(c)(2) of... Section 7086(c)(1) of the Act with respect to Cameroon and I hereby waive such restriction....

  19. High prevalence and predominance of hepatitis delta virus genotype 1 infection in Cameroon.

    Science.gov (United States)

    Foupouapouognigni, Yacouba; Noah, Dominique Noah; Sartre, Michèle Tagni; Njouom, Richard

    2011-03-01

    Antibodies to the hepatitis delta virus (HDV) were found in 17.6% of 233 hepatitis B virus surface antigen-positive subjects in Cameroon. Phylogenetic analyses showed the presence of HDV-1, HDV-5, HDV-6, and HDV-7 genotypes. These results enrich the limited data on HDV prevalence and molecular diversity in Cameroon.

  20. Economic management in neo-colonial states : a case study of Cameroon

    NARCIS (Netherlands)

    Jua, N.

    1990-01-01

    This study examines the economic management strategies adopted by the Government of Cameroon. Economic planning in Cameroon has been anchored to the principles of planned liberalism, self-reliant development, balanced development and social justice. These concepts are elaborated and it is shown that

  1. High prevalence and predominance of hepatitis delta virus genotype 1 infection in Cameroon.

    Science.gov (United States)

    Foupouapouognigni, Yacouba; Noah, Dominique Noah; Sartre, Michèle Tagni; Njouom, Richard

    2011-03-01

    Antibodies to the hepatitis delta virus (HDV) were found in 17.6% of 233 hepatitis B virus surface antigen-positive subjects in Cameroon. Phylogenetic analyses showed the presence of HDV-1, HDV-5, HDV-6, and HDV-7 genotypes. These results enrich the limited data on HDV prevalence and molecular diversity in Cameroon. PMID:21209162

  2. Volcanic Rocks and Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanoes have contributed significantly to the formation of the surface of our planet. Volcanism produced the crust we live on and most of the air we breathe. The...

  3. Volcanic hazard assessment in monogenetic volcanic fields

    OpenAIRE

    Bartolini, Stefania

    2014-01-01

    Tesi realitzada a l'Institut de Ciències de la Terra “Jaume Almera” (ICTJA-CSIC) One of the most important tasks of modern volcanology, which represents a significant socio-economic implication, is to conduct hazard assessment in active volcanic systems. These volcanological studies are aimed at hazard that allows to constructing hazard maps and simulating different eruptive scenarios, and are mainly addressed to contribute to territorial planning, definition of emergency plans or managing...

  4. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    Science.gov (United States)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  5. Volcanic hazards to airports

    Science.gov (United States)

    Guffanti, M.; Mayberry, G.C.; Casadevall, T.J.; Wunderman, R.

    2009-01-01

    Volcanic activity has caused significant hazards to numerous airports worldwide, with local to far-ranging effects on travelers and commerce. Analysis of a new compilation of incidents of airports impacted by volcanic activity from 1944 through 2006 reveals that, at a minimum, 101 airports in 28 countries were affected on 171 occasions by eruptions at 46 volcanoes. Since 1980, five airports per year on average have been affected by volcanic activity, which indicates that volcanic hazards to airports are not rare on a worldwide basis. The main hazard to airports is ashfall, with accumulations of only a few millimeters sufficient to force temporary closures of some airports. A substantial portion of incidents has been caused by ash in airspace in the vicinity of airports, without accumulation of ash on the ground. On a few occasions, airports have been impacted by hazards other than ash (pyroclastic flow, lava flow, gas emission, and phreatic explosion). Several airports have been affected repeatedly by volcanic hazards. Four airports have been affected the most often and likely will continue to be among the most vulnerable owing to continued nearby volcanic activity: Fontanarossa International Airport in Catania, Italy; Ted Stevens Anchorage International Airport in Alaska, USA; Mariscal Sucre International Airport in Quito, Ecuador; and Tokua Airport in Kokopo, Papua New Guinea. The USA has the most airports affected by volcanic activity (17) on the most occasions (33) and hosts the second highest number of volcanoes that have caused the disruptions (5, after Indonesia with 7). One-fifth of the affected airports are within 30 km of the source volcanoes, approximately half are located within 150 km of the source volcanoes, and about three-quarters are within 300 km; nearly one-fifth are located more than 500 km away from the source volcanoes. The volcanoes that have caused the most impacts are Soufriere Hills on the island of Montserrat in the British West Indies

  6. A study of yaws among pygmies in Cameroon and Zaire.

    Science.gov (United States)

    Pampiglione, S; Wilkinson, A E

    1975-06-01

    In a survey of 333 pygmies in the Cameroon 4.5 percent. were found to have clinical evidence of yaws. This was also found in 10 per cent. of the inhabitants of camps in Zaire. The results of VDRL and FTA-ABS tests on a sample of the population are presented. These provide evidence of a very high incidence of treponemal disease, 80 to 90 percent. of the population showing serological evidence of infection. Active transmission is taking place in both areas but more frequently in Zaire.

  7. Pteridophyta collected in Northern Nigeria and Northern Cameroon

    Directory of Open Access Journals (Sweden)

    Jan kornaś

    2014-02-01

    Full Text Available 25 species of Pteridophyta were collected in Northern Nigeria (mainly the Lake Chad Basin and the Mandara Mts. and in the neighbouring parts of Cameroon. 11 of them have not been recorded previously from this area: Isoetes schweinfurthii A. Br. in Bak., Selaginella tenerrima A. Br. ex Kuhn, Ophioglossum gomenzianum Welw. ex A. Br., Marsilea coromandeliana Willd., M. distorta A. Br., M. nubica A. Br., M. subterranea Lepr. ex A. Br., Azolla africana Desv., Ceratopteris richardii Brogn., Adiantum capillus-veneris Linn., and Actiniopleris semiflabellata Pic. Ser.

  8. Mycobacterium tuberculosis complex drug resistance pattern and identification of species causing tuberculosis in the West and Centre regions of Cameroon

    Directory of Open Access Journals (Sweden)

    Tedom Jean-Claude

    2011-04-01

    Full Text Available Abstract Background Data on the levels of resistance of Mycobacterium tuberculosis complex (MTBC strains to first line anti-tuberculosis drugs in Cameroon, and on the species of MTBC circulating in the country are obsolete. The picture about 10 years after the last studies, and 6 years after the re-organisation of the National Tuberculosis (TB Control Programme (NTBCP is not known. Methods The study was conducted from February to July 2009 in the West and Centre regions of Cameroon. A total of 756 suspected patients were studied. MTBC species were detected by the standard Ziehl-Neelsen staining method. Bacterial susceptibility to the first line drugs [isoniazid (INH, rifampicin (RIF, ethambutol (EMB and streptomycin (SM] were performed on cultures using the indirect proportion method. MTBC species were identified by standard biochemical and culture methods. Results Of the 756 suspected patients, 154 (20.37% were positive by smear microscopy. Of these, 20.77% were HIV patients. The growth of Mycobacterium was observed with the sputa from 149 (96.75% subjects. All the isolates were identified as either M. tuberculosis or M. africanum. Among these, 16 (10.73% were resistant to at least one drug (13.3% for the West region and 8.1% for the Centre. The initial resistance rates were 7.35% for the Centre region and 11.29% for the West region, while the acquired resistance rates were 16.66% (1/6 for the Centre region and 23.07% (3/13 for the West. Within the two regions, the highest total resistance to one drug was obtained with INH and SM (2.68% each. Multidrug-resistance (MDR was observed only in the West region at a rate of 6.67%. No resistance was recorded for EMB. Conclusions M. tuberculosis and M. africanum remain the MTBC species causing pulmonary TB in the West and Centre regions of Cameroon. Following the re-organisation of the NTBCP, resistance to all first line anti-TB drugs has declined significantly (p p

  9. Application of energy conservation policies and strategies: their effects on environment protection. Cameroon example

    International Nuclear Information System (INIS)

    The geographical situation of Cameroon, at the intersection of the semi-desert sahelian and tropical forest ecosystems, an energy consumption balance dominated by wood fuel utilization (68.5 pc.), a transportation sector responsible for 71.5 pc. of the oil consumption and of the CO/CO2 emissions, all confer to the Cameroon a particularity that put the country at the heart of the energy-environment debate: ecological threats from oil extraction and hydroelectricity production activities, desertification and global warming in Cameroon; several limited programs are taken: reforestation, enhanced wood cookers, substitution of liquid propane to wood fuel. A global strategy is under way

  10. Poverty and Share Revenue in the Cameroon Cocoa Zone

    Directory of Open Access Journals (Sweden)

    Folefack, DP.

    2010-01-01

    Full Text Available This study evaluates the revenue level and unequal poverty revenue in the Cameroonian cocoa zone. The results show a great variability on the revenues generating activities to producers of cocoa in Cameroon. These activities generate an average revenue of 1 215 622 FCFA per year, with an annual average revenue of 145 933 FCFA per person. We realize through the indice of Gini 0.61 that the concentration of these revenues is most strong in Cameroon and the poverty rate is still affecting 69% of the population. We observe as well that the average revenue of 228 263 FCFA per year and per person for the producers of South West. They are thus the richest, inspite of the high degree of concentration. In the Centre, the population have a high average annual revenue of 87 257 FCFA per person and the concentration seems to be in a lower degree. Finally, in the South we find the poorest with a revenue of 53 504 FCFA per year and per person and the concentration is more important. An analysis based on unequal indicators shows in general that the revenue per person is relatively low and the degree of concentration of revenue is stronger in the Cameroonian cocoa zone.

  11. Gynaecological morbidity among HIV positive pregnant women in Cameroon

    Directory of Open Access Journals (Sweden)

    Nana Philip N

    2008-07-01

    Full Text Available Abstract Objective To compare the prevalence of gynaecological conditions among HIV infected and non-infected pregnant women. Methods Two thousand and eight (2008 pregnant women were screened for HIV, lower genital tract infections and lower genital tract neoplasia at booking antenatal visit. Results About 10% (198/2008 were HIV positive. All lower genital tract infections except candidiasis were more prevalent among HIV positive compared to HIV negative women: vaginal candidiasis (36.9% vs 35.4%; p = 0.678, Trichomoniasis (21.2% vs 10.6%; p p p = 0.026, syphilis (35.9% vs 10.6%; p Chlamydia trachomatis (38.4% vs 7.1%; p p p Conclusion We conclude that (i sexually transmitted infections (STIs are common in both HIV positive and HIV negative pregnant women in Cameroon, and (ii STIs and preinvasive cervical lesions are more prevalent in HIV-infected pregnant women compared to their non-infected compatriots. We recommend routine screening and treatment of STIs during antenatal care in Cameroon and other countries with similar social profiles.

  12. The Weight of Health Expenditures on Household Income in Cameroon

    Directory of Open Access Journals (Sweden)

    Joseph Parfait OWOUNDI

    2014-02-01

    Full Text Available  African leaders pledged at the Abuja conference in 2001, to mobilize more financial resources to allocate at least 15% of their national budgets to the health sector to achieve the Millennium Development Goals (MDGs, seem to have difficulty meeting this commitment because of weakness and fragmentation of health systems. These commitments were renewed in Gaborone, Botswana in 2005 and in Ouagadougou, Burkina Faso in 2006. Indeed, donor funding is still a large part of public health spending on the continent. In some countries, 50% or more of their budgets come from foreign or private assistance. In about half the countries, the private health financing is equal to or exceeds largely public funding, up to 70% in some states like Sudan, Côte d'Ivoire, Cameroon, Chad, Liberia and Uganda. Only five countries (Rwanda, Malawi, Zambia, Burkina Faso, and Togo have so far respected the promise made to the Abuja conference. In Cameroon, where 51% of the population lives on less than two dollars per day, the average propensity of the total medical consumption is very high. Indeed, 32% of households spend less than half of income on health, while 16% of households spend more than half of the income and 52% spend more than the total income. This corresponds to a weight of 68% in health care spending.  

  13. Local governance in disaster risk reduction in Cameroon

    Directory of Open Access Journals (Sweden)

    Buh-Wung Gaston

    2012-06-01

    Full Text Available At the 2005 World Conference on Disaster Risk Reduction held in Hyogo, Japan, 168 countries including Cameroon adopted the Hyogo Framework for Action, committing to take action to reduce human and socio-economic disaster losses. Geotechnology, Environmental Assessment and Disaster Risk Reduction was commissioned by the Global Network of Civil Society Organisations for Disaster Risk Reduction as the coordinating organisation in Cameroon to evaluate progress in implementation of the framework from the civil society perspective, particularly the role of local governance in disaster risk reduction (DRR. Seven regions of the country were identified for evaluation, where people have suffered losses from disasters during the last three decades. Three approaches were used: administration of questionnaires; consultations with local communities; and four case studies. It was found that there was significant scope for improvement on individual local governance indicators, and that effective progress depends on:1. level of achievement in the decentralisation process currently under way.2. adoption of a participatory approach to DRR.3. clear distribution of roles in the DRR process.4. adequate allocation of necessary financial and human resources.5. enhancement of capacity of local communities to prepare for and respond to all types of disasters.Creation of an independent body to carry out fundamental research, forecast new and emerging hazards and manage all disasters in the country will contribute greatly to moving things forward.

  14. Volcanism and Oil & Gas In Northeast China

    Institute of Scientific and Technical Information of China (English)

    Shan Xuanlong

    2000-01-01

    Based on study on the relation with volcanic rock and oil & gas in Songliao Basin and Liaohe Basin in northeast China, author proposes that material from deep by volcanism enrichs the resources in basins, that heat by volcanism promotes organic matter transforming to oil and gas, that volcanic reservoir is fracture, vesicular, solution pore, intercrystal pore.Lava facies and pyroclastic facies are favourable reservoir. Mesozoic volcanic reservoir is majority of intermediate, acid rock,but Cenozoic volcanic reservoir is majority of basalt. Types of oil and gas pool relating to volcanic rock include volcanic fracture pool, volcanic unconformity pool, volcanic rock - screened pool, volcanic darpe structural pool.

  15. Modeling volcanic ash dispersal

    CERN Document Server

    CERN. Geneva

    2010-01-01

    The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard...

  16. Virological outcome and patterns of HIV-1 drug resistance in patients with 36 months’ antiretroviral therapy experience in Cameroon

    Directory of Open Access Journals (Sweden)

    Avelin F Aghokeng

    2013-01-01

    Full Text Available Introduction: The current expansion of antiretroviral treatment (ART in the developing world without routine virological monitoring still raises concerns on the outcome of the strategy in terms of virological success and drug resistance burden. We assessed the virological outcome and drug resistance mutations in patients with 36 months’ ART experience, and monitored according to the WHO public health approach in Cameroon. Methods: We consecutively recruited between 2008 and 2009 patients attending a national reference clinic in Yaoundé – Cameroon, for their routine medical visits at month 36±2. Observance data and treatment histories were extracted from medical records. Blood samples were collected for viral load (VL testing and genotyping of drug resistance when HIV-1 RNA≥1000 copies/ml. Results: Overall, 376 HIV-1 infected adults were recruited during the study period. All, but four who received PMTCT, were ART-naïve at treatment initiation, and 371/376 (98.7% started on a first-line regimen that included 3TC +d4T/AZT+NVP/EFV. Sixty-six (17.6% patients experienced virological failure (VL≥1000 copies/ml and 53 carried a resistant virus, thus representing 81.5% (53/65 of the patients who failed. Forty-two out of 53 were resistant to nucleoside and non-nucleoside reverse-transcriptase inhibitors (NRTIs+NNRTIs, one to protease inhibitors (PI and NNRTIs, two to NRTIs only and eight to NNRTIs only. Among patients with NRTI resistance, 18/44 (40.9% carried Thymidine Analog Mutations (TAMs, and 13/44 (29.5% accumulated at least three NRTI resistance mutations. Observed NNRTI resistance mutations affected drugs of the regimen, essentially nevirapine and efavirenz, but several patients (10/51, 19.6% accumulated mutations that may have compromised etravirine use. Conclusions: We observed a moderate level of virological failure after 36 months of treatment, but a high proportion of patients who failed developed drug resistance. Although we

  17. Food habits of two sciaenid fish species (Pseudotolithus typus and Pseudotolithus senegalensis) off Cameroon

    OpenAIRE

    Tientcheu, J.Y.; Djama, T.

    1994-01-01

    Pseudotolithus typus and P. senegalensis (Sciaenidae) sampled off Cameroon Coast, West Africa, have been found to feed mainly on shrimps (Nematoplaemon hastatus and Parapenaeopsis atlantica) and juvenile fish (mostly clupeids). The diet composition is presented and discussed.

  18. A comprehensive mapping of the current capacity for human nutrition training in Cameroon

    OpenAIRE

    Sodjinou, Roger; Lezama, Ines; Asse, Marie-Louise; Okala, Georges; William K. Bosu; Fanou, Nadia; Mbala, Ludvine; Zagre, Noel Marie; Tchibindat, Félicité; Delisle, Helene

    2016-01-01

    Background: There is consensus among stakeholders in Cameroon on the need to develop and strengthen human resource capacity for nutrition. This study was conducted to provide a comprehensive mapping of the current capacity for tertiary-level human nutrition training in Cameroon.Design: Participating institutions included university-level institutions offering dedicated nutrition degree programs or other programs in which nutrition courses were taught. A semi-structured questionnaire administe...

  19. A comprehensive mapping of the current capacity for human nutrition training in Cameroon

    OpenAIRE

    Roger Sodjinou; Ines Lezama; Marie-Louise Asse; Georges Okala; William K. Bosu; Nadia Fanou; Ludvine Mbala; Noel Marie Zagre; Félicité Tchibindat

    2016-01-01

    Background: There is consensus among stakeholders in Cameroon on the need to develop and strengthen human resource capacity for nutrition. This study was conducted to provide a comprehensive mapping of the current capacity for tertiary-level human nutrition training in Cameroon. Design: Participating institutions included university-level institutions offering dedicated nutrition degree programs or other programs in which nutrition courses were taught. A semi-structured questionnaire administ...

  20. A crispy dedicacy : Augosoma beetle as alternative source of protein in East Cameroon

    OpenAIRE

    F. J. Muafor; Levang, Patrice; Le Gall, Philippe

    2014-01-01

    Despite the fact that the exoskeleton of the Augosoma centaurus (Dynastinae) is hard and difficult to chew, this insect is often gathered in Eastern Cameroon for food in periods of availability. Nine ethnic groups in Eastern Cameroon were surveyed to understand the role of this insect in assuring food security, using quantitative and qualitative social science approaches. Both the larvae and adult stages of this beetle are habitually consumed in the areas studied. In total, about 65%...

  1. A Crispy Delicacy: Augosoma Beetle as Alternative Source of Protein in East Cameroon

    OpenAIRE

    F. J. Muafor; Levang, P.; Le Gall, P

    2014-01-01

    Despite the fact that the exoskeleton of the Augosoma centaurus (Dynastinae) is hard and difficult to chew, this insect is often gathered in Eastern Cameroon for food in periods of availability. Nine ethnic groups in Eastern Cameroon were surveyed to understand the role of this insect in assuring food security, using quantitative and qualitative social science approaches. Both the larvae and adult stages of this beetle are habitually consumed in the areas studied. In total, about 65% of consu...

  2. Governance of disaster risk reduction in Cameroon: The need to empower local government

    OpenAIRE

    Bang, Henry N.

    2013-01-01

    The impact of natural hazards and/or disasters in Cameroon continues to hit local communities hardest, but local government lacks the ability to manage disaster risks adequately. This is partly due to the fact that the necessity to mainstream disaster risk reduction into local governance and development practices is not yet an underlying principle of Cameroon’s disaster management framework. Using empirical and secondary data, this paper analyses the governance of disaster risks in Cameroon w...

  3. Human Resource Management Issues at a Rising Entrepreneurial Company in Cameroon: Employees' Perspective

    OpenAIRE

    DeLancey, Rebecca Mbuh

    2015-01-01

    This case study examines the human resources practices in Universal-Cameroon Link, a promising small business in Cameroon. In-depth interviews were conducted with current and past employees to gain insight into their perspectives on management implementation of human resource management strategies and their (non-)effectiveness. Management treatment of employees not as significant contributors to the growth and success of the business, but mere as "tools" has resulted in distrust from both par...

  4. An Examination of Forest Certification Status among Logging Companies in Cameroon

    OpenAIRE

    Nukpezah, Daniel; Alemagi, Dieudonne; Duguma, Lalisa; Minang, Peter; Mbosso, Charlie; Tchoundjeu, Zac

    2014-01-01

    This paper assesses the level of interest, awareness, and adoption of ISO 14001 and Forest Stewardship Council (FSC) certification schemes among logging companies in Cameroon. Eleven logging companies located in Douala in the Littoral Region of Cameroon were assessed through a structured interview using an administered questionnaire which was mostly analyzed qualitatively thereafter. The findings indicated that none of the companies was certified for ISO 14001; however 63.64% of them were alr...

  5. Retention in an antiretroviral therapy programme during an era of decreasing drug cost in Limbe, Cameroon

    OpenAIRE

    Mosoko Jembia J; Akam Wilfred; Weidle Paul J; Brooks John T; Aweh Asabi J; Kinge Thompson N; Pals Sherri; Raghunathan Pratima L

    2011-01-01

    Abstract Background In 2002, Cameroon initiated scale up of antiretroviral therapy (ART); on 1 October 2004, a substantial reduction in ART cost occurred. We assessed the impact of this event and other factors on enrolment and retention in care among HIV-infected patients initiating ART from February 2002 to December 2005 at the single ART clinic serving the Southwest Region in Limbe, Cameroon. Methods We retrospectively analyzed clinical and pharmacy payment records of HIV-infected patients ...

  6. THE IMPACTS OF SURFACE TRANSPORT DEVELOPMENT TO TOURISM GROWTH : A case study of roads in Cameroon

    OpenAIRE

    Ngoye, Charles

    2016-01-01

    Cameroon is often referred to as Africa in miniature. Endowed with abundant touristic potential but not a popular tourist’s destination. In this nation can be found almost every touristic attraction that can be seen in all parts of Africa and others that can be found here and not elsewhere. It has three climate zones to feed the tourist tastes which is scarcely to be anywhere in Africa This splendid destination Cameroon has attractions like waterfalls, lakes, mountains, natural beaches, game ...

  7. Increased Carotid Thickness in Subjects with Recently-Diagnosed Diabetes from Rural Cameroon

    OpenAIRE

    Nicola Napoli; Enrico Zardi; Rocky Strollo; Michele Arigliani; Andrea Daverio; Flaminia Olearo; Daniele Tosi; Giordano Dicuonzo; Filomena Scarpa; Claudio Pedone; Hervé Hilaire Tegue Simo; Giovanni Mottini; Paolo Pozzilli

    2012-01-01

    BACKGROUND: We have recently shown a high prevalence of diabetes and obesity in rural Cameroon, despite an improved lifestyle. Diabetes in rural Africa remains underdiagnosed and its role in increasing risk of atherosclerosis in these populations is unknown. We investigated the prevalence of carotid atherosclerosis and cardiovascular risk factors in a population of subjects with recently-diagnosed diabetes from rural Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: In a case-control study, carotid i...

  8. Hospital workers' awareness of health and environmental impacts of poor clinical waste disposal in the Northwest Region of Cameroon

    DEFF Research Database (Denmark)

    Mochungong, Peter I K; Gulis, Gabriel; Sodemann, Morten

    2010-01-01

    a survey to evaluate hospital workers' awareness of health and environmental impacts of poor clinical waste disposal in Cameroon. We randomly distributed 500 questionnaires to hospital workers in three hospitals in the Northwest Region of Cameroon in April 2008. In addition, we observed collection...... management. Methods of collecting, segregating, transporting and disposing clinical waste at the three hospitals was poor. The development of a comprehensive policy on efficient clinical waste management in Cameroon is imperative....

  9. Hospital Workers' Awareness of Health and Environmental Impacts of Poor Clinical Waste Disposal in the Northwest Region of Cameroon

    DEFF Research Database (Denmark)

    Mochungong, Peter I. K.; Gulis, Gabriel; Sodemann, Morten

    2010-01-01

    a survey to evaluate hospital workers' awareness of health and environmental impacts of poor clinical waste disposal in Cameroon. We randomly distributed 500 questionnaires to hospital workers in three hospitals in the Northwest Region of Cameroon in April 2008. In addition, we observed collection...... management. Methods of collecting, segregating, transporting and disposing clinical waste at the three hospitals was poor. The development of a comprehensive policy on efficient clinicalwaste management in Cameroon is imperative....

  10. Mapping of Bancroftian Filariasis in Cameroon: Prospects for Elimination.

    Directory of Open Access Journals (Sweden)

    Hugues C Nana-Djeunga

    Full Text Available Lymphatic filariasis (LF is one of the most debilitating neglected tropical diseases (NTDs. It still presents as an important public health problem in many countries in the tropics. In Cameroon, where many NTDs are endemic, only scant data describing the situation regarding LF epidemiology was available. The aim of this study was to describe the current situation regarding LF infection in Cameroon, and to map this infection and accurately delineate areas where mass drug administration (MDA was required.The endemicity status and distribution of LF was assessed in eight of the ten Regions of Cameroon by a rapid-format card test for detection of W. bancrofti antigen (immunochromatographic test, ICT. The baseline data required to monitor the effectiveness of MDA was collected by assessing microfilariaemia in nocturnal calibrated thick blood smears in sentinel sites selected in the health districts where ICT positivity rate was ≥ 1%.Among the 120 health districts visited in the eight Regions during ICT survey, 106 (88.3% were found to be endemic for LF (i.e. had ICT positivity rate ≥ 1%, with infection rate from 1.0% (95% CI: 0.2-5.5 to 20.0% (95% CI: 10-30. The overall infection rate during the night blood survey was 0.11% (95% CI: 0.08-0.16 in 11 health districts out of the 106 surveyed; the arithmetic mean for microfilaria density was 1.19 mf/ml (95% CI: 0.13-2.26 for the total population examined.ICT card test results showed that LF was endemic in all the Regions and in about 90% of the health districts surveyed. All of these health districts qualified for MDA (i.e. ICT positivity rate ≥ 1%. Microfilariaemia data collected as part of this study provided the national program with baseline data (sentinel sites necessary to measure the impact of MDA on the endemicity level and transmission of LF important for the 2020 deadline for global elimination.

  11. Mapping of Bancroftian Filariasis in Cameroon: Prospects for Elimination

    Science.gov (United States)

    Nana-Djeunga, Hugues C.; Tchatchueng-Mbougua, Jules B.; Bopda, Jean; Mbickmen-Tchana, Steve; Elong-Kana, Nathalie; Nnomzo’o, Etienne; Akame, Julie; Tarini, Ann; Zhang, Yaobi; Njiokou, Flobert; Kamgno, Joseph

    2015-01-01

    Background Lymphatic filariasis (LF) is one of the most debilitating neglected tropical diseases (NTDs). It still presents as an important public health problem in many countries in the tropics. In Cameroon, where many NTDs are endemic, only scant data describing the situation regarding LF epidemiology was available. The aim of this study was to describe the current situation regarding LF infection in Cameroon, and to map this infection and accurately delineate areas where mass drug administration (MDA) was required. Methodology The endemicity status and distribution of LF was assessed in eight of the ten Regions of Cameroon by a rapid-format card test for detection of W. bancrofti antigen (immunochromatographic test, ICT). The baseline data required to monitor the effectiveness of MDA was collected by assessing microfilariaemia in nocturnal calibrated thick blood smears in sentinel sites selected in the health districts where ICT positivity rate was ≥ 1%. Principal findings Among the 120 health districts visited in the eight Regions during ICT survey, 106 (88.3%) were found to be endemic for LF (i.e. had ICT positivity rate ≥ 1%), with infection rate from 1.0% (95% CI: 0.2–5.5) to 20.0% (95% CI: 10–30). The overall infection rate during the night blood survey was 0.11% (95% CI: 0.08–0.16) in 11 health districts out of the 106 surveyed; the arithmetic mean for microfilaria density was 1.19 mf/ml (95% CI: 0.13–2.26) for the total population examined. Conclusion/significance ICT card test results showed that LF was endemic in all the Regions and in about 90% of the health districts surveyed. All of these health districts qualified for MDA (i.e. ICT positivity rate ≥ 1%). Microfilariaemia data collected as part of this study provided the national program with baseline data (sentinel sites) necessary to measure the impact of MDA on the endemicity level and transmission of LF important for the 2020 deadline for global elimination. PMID:26353087

  12. Exploring Hawaiian volcanism

    Science.gov (United States)

    Poland, Michael P.; Okubo, Paul G.; Hon, Ken

    2013-01-01

    In 1912 the Hawaiian Volcano Observatory (HVO) was established by Massachusetts Institute of Technology professor Thomas A. Jaggar Jr. on the island of Hawaii. Driven by the devastation he observed while investigating the volcanic disasters of 1902 at Montagne Pelée in the Caribbean, Jaggar conducted a worldwide search and decided that Hawai‘i provided an excellent natural laboratory for systematic study of earthquake and volcano processes toward better understanding of seismic and volcanic hazards. In the 100 years since HVO’s founding, surveillance and investigation of Hawaiian volcanoes have spurred advances in volcano and seismic monitoring techniques, extended scientists’ understanding of eruptive activity and processes, and contributed to development of global theories about hot spots and mantle plumes.

  13. Reducing volcanic risk

    Science.gov (United States)

    Decker, R.; Decker, B.

    1991-01-01

    The last two decades have brought major advances in research on how volcanoes work and how to monitor their changing habits. Geologic mapping as well as studies of earthquake patterns and surface deformation associated with underground movement of magma have given scientists a better view of the inner structure and dynamics of active volcanoes. With the next decade, the time has come to focuses more on applying this knowledge toward reducing the risk from volcanic activity on a worldwide basis. 

  14. Geomagnetic imprint of the Persani volcanism

    Science.gov (United States)

    Besutiu, Lucian; Seghedi, Ioan; Zlagnean, Luminita; Atanasiu, Ligia; Popa, Razvan-Gabriel; Pomeran, Mihai; Visan, Madalina

    2016-04-01

    employing various filtering techniques. Thus, the reduction-to-the-pole or pseudo-gravity operators have allowed for an improved source positioning, distorted by the inclination of the geomagnetic vector, while high-order derivatives (e.g. horizontal and vertical gradients) have better outlined the contour of the hidden magnetic bodies. Overall, the geomagnetic survey has confirmed the assumptions previously inferred by geological field work. Besides, it helped identify several unrevealed buried volcanic forms and their relation to structural elements (e.g. fault aligned vents, and larger circular structures). In-depth development of the volcanic structures has been studied along several interpretative lines by using inversion and 2D forward modelling of geomagnetic data under rock magnetic properties constraints provided by lab analyses. Acknowledgements. The research was funded through CNCS - UEFISCDI, project number PN-II-ID-PCE-2012-4-0137.

  15. Subdiffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2016-01-01

    A comparative study is performed on volcanic seismicities at Mt.Eyjafjallajokull in Iceland and Mt. Etna in Sicily, Italy, from the viewpoint of science of complex systems, and the discovery of remarkable similarities between them regarding their exotic spatio-temporal properties is reported. In both of the volcanic seismicities as point processes, the jump probability distributions of earthquakes are found to obey the exponential law, whereas the waiting-time distributions follow the power law. In particular, a careful analysis is made about the finite size effects on the waiting-time distributions, and accordingly, the previously reported results for Mt. Etna [S. Abe and N. Suzuki, EPL 110, 59001 (2015)] are reinterpreted. It is shown that spreads of the volcanic earthquakes are subdiffusive at both of the volcanoes. The aging phenomenon is observed in the "event-time-averaged" mean-squared displacements of the hypocenters. A comment is also made on presence/absence of long term memories in the context of t...

  16. Wealth and sexual behaviour among men in Cameroon

    Directory of Open Access Journals (Sweden)

    Nana Philip

    2006-09-01

    Full Text Available Abstract Background The 2004 Demographic and Health Survey (DHS in Cameroon revealed a higher prevalence of HIV in richest and most educated people than their poorest and least educated compatriots. It is not certain whether the higher prevalence results partly or wholly from wealthier people adopting more unsafe sexual behaviours, surviving longer due to greater access to treatment and care, or being exposed to unsafe injections or other HIV risk factors. As unsafe sex is currently believed to be the main driver of the HIV epidemic in sub-Saharan Africa, we designed this study to examine the association between wealth and sexual behaviour in Cameroon. Methods We analysed data from 4409 sexually active men aged 15–59 years who participated in the Cameroon DHS using logistic regression models, and have reported odds ratios (OR with confidence intervals (CI. Results When we controlled for the potential confounding effects of marital status, place of residence, religion and age, men in the richest third of the population were less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.43, 95% CI 0.32–0.56 and more likely to have had at least two concurrent sex partners in the last 12 months (OR 1.38, 95% CI 1.12–1.19 and more than five lifetime sex partners (OR 1.97, 95% CI 1.60–2.43. However, there was no difference between the richest and poorest men in the purchase of sexual services. Regarding education, men with secondary or higher education were less likely to have used a condom in the last sex with a non-spousal non-cohabiting partner (OR 0.24, 95% CI 0.16–0.38 and more likely to have started sexual activity at age 17 years or less (OR 2.73, 95% CI 2.10–3.56 and had more than five lifetime sexual partners (OR 2.59, 95% CI 2.02–3.31. There was no significant association between education and multiple concurrent sexual partnerships in the last 12 months or purchase of sexual services

  17. Paths to Attaining Food Security: The Case of Cameroon

    Directory of Open Access Journals (Sweden)

    Genesis T. Yengoh

    2010-08-01

    Full Text Available This paper sets out to develop a framework for characterizing agricultural growth orientations. We identify four main components in the global food system (technology, institutions, people, and natural resources. Based on the extent to which any two of these components are important in driving the growth of agriculture, we distinguish four main orientations of agricultural growth: local food, high resource-technology driven, guided technology driven, and right-to-food growth orientations. Given the social and environmental challenges that agricultural growth has to meet in Cameroon, we argue that the local food orientation and guided technology-driven orientation offer better opportunities for meeting the problem of food security in this country.

  18. Alcohol use and extramarital sex among men in Cameroon

    Directory of Open Access Journals (Sweden)

    Wiysonge Charles

    2007-08-01

    Full Text Available Abstract Background The spread of HIV in sub-Saharan Africa is believed to be driven by unsafe sex, and identification of modifiable risk factors of the latter is needed for comprehensive HIV prevention programming in the region. Some previous studies suggest an association between alcohol abuse and unsafe sexual behaviour, such as multiple concurrent sexual partnerships and inconsistent condom use in sex with non-spousal non-cohabiting partners. However, most of these studies were conducted in developed countries and the few studies in Africa were conducted among well-defined social groups such as men attending beer halls or sexually transmitted infection clinics. We therefore examined the association between alcohol and extramarital sex (a sign of multiple concurrent sexual partnerships among men in a population-based survey in Cameroon; a low-income country in sub-Saharan Africa with a high rate of alcohol abuse and a generalised HIV epidemic. Methods We analyzed data from 2678 formally married or cohabiting men aged 15 to 59 years, who participated in the 2004 Cameroon Demographic and Health Survey, using a multivariate regression model. Results A quarter of the men (25.8% declared having taken alcohol before their last sexual intercourse and 21% indicated that the last sex was with a woman other than their wife or cohabiting partner. After controlling for possible confounding by other socio-demographic characteristics, alcohol use was significantly associated with having extramarital sex: adjusted odds ratio (OR 1.70, 95% confidence intervals (CI 1.40 to 2.05. Older age (30–44 years: OR 3.06, 95%CI 2.16–4.27 and 45–59 years: OR 4.10, 95%CI 2.16–4.27, higher education (OR 1.25, 95%CI 1.10–1.45, and wealth (OR 1.71, 95%CI 1.50–1.98 were also significantly associated with higher odds of having extramarital sex. The men were more likely to have used a condom in their last sex if it was extramarital (OR 10.50, 95%CI 8.10–13

  19. Timing of Premarital Intercourse in Bandjoun (West Cameroon

    Directory of Open Access Journals (Sweden)

    Zacharie Tsala Dimbuene

    2013-03-01

    Full Text Available This article examined the effects of family environment on the risks of premarital intercourse for male and female youth. Previous research in sub-Saharan Africa (SSA on the linkages between family structures and sexual debut mainly utilized cross-sectional data. In a sample drawn from Cameroon Family and Health Survey (N = 2,166, descriptive and multivariate results showed that youth who resided in nuclear two-parent families, those who reported higher levels of parental monitoring and higher quality of parent–child relationships during childhood and/or adolescence, had significantly lower rates of premarital intercourse. Polygynous families, parent–child communication, orphanhood, and change in family structure were significantly associated with higher rates of premarital intercourse. Programmatic implications for reproductive health interventions in SSA are discussed.

  20. Mechanisms for Quality Assurance of Universities in Cameroon

    Directory of Open Access Journals (Sweden)

    Joseph BESONG BESONG

    2016-06-01

    Full Text Available This paper takes a perspective look at the evolution of universities in Cameroon and the recent orientation of deregulation as it affects quality assurance in Cameroonian universities. The paper having identified these flaws attempted to elucidate the meaning of mechanism for Quality assurance in the face of deregulation. The regulatory mechanisms identified by this paper include inter- alia, appropriate scrutiny of new programmes, relying on impartial advise of examiners. Using the state law NO.98/004 of 1998 to compliment the efforts of internal school administration and above all opening linkages between universities and relating universities education in the World of science and technology. This paper does not only enhance quality assurance but also builds the idea of economic growth and development.

  1. Tracing the origins of rescued chimpanzees reveals widespread chimpanzee hunting in Cameroon

    Directory of Open Access Journals (Sweden)

    Gadsby Elizabeth L

    2010-01-01

    Full Text Available Abstract Background While wild chimpanzees are experiencing drastic population declines, their numbers at African rescue and rehabilitation projects are growing rapidly. Chimpanzees follow complex routes to these refuges; and their geographic origins are often unclear. Identifying areas where hunting occurs can help law enforcement authorities focus scarce resources for wildlife protection planning. Efficiently focusing these resources is particularly important in Cameroon because this country is a key transportation waypoint for international wildlife crime syndicates. Furthermore, Cameroon is home to two chimpanzee subspecies, which makes ascertaining the origins of these chimpanzees important for reintroduction planning and for scientific investigations involving these chimpanzees. Results We estimated geographic origins of 46 chimpanzees from the Limbe Wildlife Centre (LWC in Cameroon. Using Bayesian approximation methods, we determined their origins using mtDNA sequences and microsatellite (STRP genotypes compared to a spatial map of georeferenced chimpanzee samples from 10 locations spanning Cameroon and Nigeria. The LWC chimpanzees come from multiple regions of Cameroon or forested areas straddling the Cameroon-Nigeria border. The LWC chimpanzees were partitioned further as originating from one of three biogeographically important zones occurring in Cameroon, but we were unable to refine these origin estimates to more specific areas within these three zones. Conclusions Our findings suggest that chimpanzee hunting is widespread across Cameroon. Live animal smuggling appears to occur locally within Cameroon, despite the existence of local wildlife cartels that operate internationally. This pattern varies from the illegal wildlife trade patterns observed in other commercially valuable species, such as elephants, where specific populations are targeted for exploitation. A broader sample of rescued chimpanzees compared against a more

  2. Maternal mortality in Cameroon: a university teaching hospital report.

    Science.gov (United States)

    Tebeu, Pierre-Marie; Pierre-Marie, Tebeu; Halle-Ekane, Gregory; Gregory, Halle-Ekane; Da Itambi, Maxwell; Maxwell, Da Itambi; Enow Mbu, Robinson; Robinson, Enow Mbu; Mawamba, Yvette; Yvette, Mawamba; Fomulu, Joseph Nelson; Nelson, Fomulu Joseph

    2015-01-01

    More than 550,000 women die yearly from pregnancy-related causes. Fifty percent (50%) of the world estimate of maternal deaths occur in sub-Saharan Africa alone. There is insufficient information on the risk factors of maternal mortality in Cameroon. This study aimed at establishing causes and risk factors of maternal mortality. This was a case-control study from 1st January, 2006 to 31st December, 2010 after National Ethical Committee Approval. Cases were maternal deaths; controls were women who delivered normally. Maternal deaths were obtained from the delivery room registers and in-patient registers. Controls for each case were two normal deliveries following identified maternal deaths on the same day. Variables considered were socio-demographic and reproductive health characteristics. Epi Info 3.5.1 was used for analysis. The mean MMR was 287.5/100,000 live births. Causes of deaths were: postpartum hemorrhage (229.2%), unsafe abortion (25%), ectopic pregnancy (12.5%), hypertension in pregnancy (8.3%), malaria (8.3%), anemia (8.3%), heart disease (4.2%), and pneumonia (4.2%), and placenta praevia (4.2%). Ages ranged from 18 to 41 years, with a mean of 27.7 ± 5.14 years. Lack of antenatal care was a risk factor for maternal death (OR=78.33; CI: (8.66- 1802.51)). The mean MMR from 2006 to 2010 was 287.5/100,000 live births. Most of the causes of maternal deaths were preventable. Lack of antenatal care was a risk factor for maternal mortality. Key words: Maternal mortality, causes, risk factors, Cameroon.

  3. Maternal mortality in Cameroon: a university teaching hospital report.

    Science.gov (United States)

    Tebeu, Pierre-Marie; Pierre-Marie, Tebeu; Halle-Ekane, Gregory; Gregory, Halle-Ekane; Da Itambi, Maxwell; Maxwell, Da Itambi; Enow Mbu, Robinson; Robinson, Enow Mbu; Mawamba, Yvette; Yvette, Mawamba; Fomulu, Joseph Nelson; Nelson, Fomulu Joseph

    2015-01-01

    More than 550,000 women die yearly from pregnancy-related causes. Fifty percent (50%) of the world estimate of maternal deaths occur in sub-Saharan Africa alone. There is insufficient information on the risk factors of maternal mortality in Cameroon. This study aimed at establishing causes and risk factors of maternal mortality. This was a case-control study from 1st January, 2006 to 31st December, 2010 after National Ethical Committee Approval. Cases were maternal deaths; controls were women who delivered normally. Maternal deaths were obtained from the delivery room registers and in-patient registers. Controls for each case were two normal deliveries following identified maternal deaths on the same day. Variables considered were socio-demographic and reproductive health characteristics. Epi Info 3.5.1 was used for analysis. The mean MMR was 287.5/100,000 live births. Causes of deaths were: postpartum hemorrhage (229.2%), unsafe abortion (25%), ectopic pregnancy (12.5%), hypertension in pregnancy (8.3%), malaria (8.3%), anemia (8.3%), heart disease (4.2%), and pneumonia (4.2%), and placenta praevia (4.2%). Ages ranged from 18 to 41 years, with a mean of 27.7 ± 5.14 years. Lack of antenatal care was a risk factor for maternal death (OR=78.33; CI: (8.66- 1802.51)). The mean MMR from 2006 to 2010 was 287.5/100,000 live births. Most of the causes of maternal deaths were preventable. Lack of antenatal care was a risk factor for maternal mortality. Key words: Maternal mortality, causes, risk factors, Cameroon. PMID:26401210

  4. Are there biomedical criteria to assess an acute carbon dioxide intoxication by a volcanic emission?

    Science.gov (United States)

    Stupfel, Maurice; Le Guern, François

    1989-11-01

    On August 21, 1987, more than 1800 people, thousands of head of cattle and countless wild animals, including birds, were killed by a gas release which occurred during about 4 hours at the lake in the crater Iwi at Nyos in Cameroon; plant life was mostly unaffected. An international inquiry was performed by British, French, Italian, Japanese and U.S. volcanologists and physicians to determine what had been the cause of this disaster. An international conference organised by United Nations Educational Scientific, and Cultural Organisation (U.N.E.S.C.O.), the Cameroon Government and the U.N. Economic Commission for Africa held in Yaoundé March, 1987 concluded: 'that the cause of sudden death was suffocation (asphyxia) in a carbon dioxide atmosphere' The medical findings have been explained by asphyxia caused by carbon dioxide. The presence of other volcanic gases, e.g. hydrogen sulfide, cannot be ruled out' (Sigvaldason, 1989, this issue). This paper reviews what is mainly known about an acute carbon dioxide intoxication in order to disprove or confirm the diagnosis and helps to interpret the field observations and testimonies to provide a basis to discuss the prevention of such an intoxication.

  5. Batrachochytrium dendrobatidis in amphibians of Cameroon, including first records for caecilians.

    Science.gov (United States)

    Doherty-Bone, T M; Gonwouo, N L; Hirschfeld, M; Ohst, T; Weldon, C; Perkins, M; Kouete, M T; Browne, R K; Loader, S P; Gower, D J; Wilkinson, M W; Rödel, M O; Penner, J; Barej, M F; Schmitz, A; Plötner, J; Cunningham, A A

    2013-02-28

    Amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has been hypothesised to be an indigenous parasite of African amphibians. In Cameroon, however, previous surveys in one region (in the northwest) failed to detect this pathogen, despite the earliest African Bd having been recorded from a frog in eastern Cameroon, plus one recent record in the far southeast. To reconcile these contrasting results, we present survey data from 12 localities across 6 regions of Cameroon from anurans (n = 1052) and caecilians (n = 85) of ca. 108 species. Bd was detected in 124 amphibian hosts at 7 localities, including Mt. Oku, Mt. Cameroon, Mt. Manengouba and lowland localities in the centre and west of the country. None of the hosts were observed dead or dying. Infected amphibian hosts were not detected in other localities in the south and eastern rainforest belt. Infection occurred in both anurans and caecilians, making this the first reported case of infection in the latter order (Gymnophiona) of amphibians. There was no significant difference between prevalence and infection intensity in frogs and caecilians. We highlight the importance of taking into account the inhibition of diagnostic qPCR in studies on Bd, based on all Bd-positive hosts being undetected when screened without bovine serum albumin in the qPCR mix. The status of Bd as an indigenous, cosmopolitan amphibian parasite in Africa, including Cameroon, is supported by this work. Isolating and sequencing strains of Bd from Cameroon should now be a priority. Longitudinal host population monitoring will be required to determine the effects, if any, of the infection on amphibians in Cameroon.

  6. Volcanic Ash Nephelometer Probe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced dropsondes that could effectively be guided through atmospheric regions of interest such as volcanic plumes may enable unprecedented observations of...

  7. Volcanic Eruptions and Climate

    Science.gov (United States)

    Robock, A.

    2012-12-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of these aerosol clouds produce responses in the climate system. Observations and numerical models of the climate system show that volcanic eruptions produce global cooling and were the dominant natural cause of climate change for the past millennium, on timescales from annual to century. Major tropical eruptions produce winter warming of Northern Hemisphere continents for one or two years, while high latitude eruptions in the Northern Hemisphere weaken the Asian and African summer monsoon. The Toba supereruption 74,000 years ago caused very large climate changes, affecting human evolution. However, the effects did not last long enough to produce widespread glaciation. An episode of four large decadally-spaced eruptions at the end of the 13th century C.E. started the Little Ice Age. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade had a small effect on global temperature trends. The June 13, 2011 Nabro eruption in Eritrea produced the largest stratospheric aerosol cloud since Pinatubo, and the most of the sulfur entered the stratosphere not by direct injection, but by slow lofting in the Asian summer monsoon circulation. Volcanic eruptions warn us that while stratospheric geoengineering could cool the surface, reducing ice melt and sea level rise, producing pretty sunsets, and increasing the CO2 sink, it could also reduce summer monsoon precipitation, destroy ozone, allowing more harmful UV at the surface, produce rapid warming when stopped, make the sky white, reduce solar power, perturb the ecology with more diffuse radiation, damage airplanes flying in the stratosphere, degrade astronomical observations, affect remote sensing, and affect

  8. Quaternary basaltic volcanism in the Payenia volcanic province, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina

    Pleistocene times. These basalts mark the end of a period of shallow subduction of the Nazca slab beneath the Payenia province and volcanism in the Nevado volcanic field apparently followed the downwarping slab in a north-northwest direction ending in the Northern Segment. The northern Payenia basalts...

  9. Sustainable Development and Corporate Social Responsibility in Sub-Saharan Africa: Evidence from Industries in Cameroon

    Directory of Open Access Journals (Sweden)

    Oyewole Simon Oginni

    2016-05-01

    Full Text Available Present technological innovations and social organizations continue to impose risks and limitations on the efficient performance of the biosphere. Human activities have increasingly short-lived sustainable natural endowments, to the extent that, the multiplier effects have ripples beyond the traditional benefits of economic production and consumption. Therefore, this study addressed practical concerns on how industries in Sub-Saharan Africa promote sustainable development in their corporate social responsibility models, using industries in Cameroon as a case study; it examined economic, social, and environmental components of sustainable development and corporate social responsibility (CSR. Our sample consists of 335 business enterprises from the last Censure Survey of Enterprises in Cameroon. The study adopted a systematic analysis through the Adjusted Residual Test, and the Phi and Cramer’s V tests. Findings revealed that industries in Cameroon prioritize environmental and social dimensions over economic dimensions. However, a few large enterprises implement a broad CSR that promotes sustainable business practices, whereas smaller ones do not; industries in Cameroon implement environmental dimensions of CSR as a safe buffer and a social dimension as philanthropy. Hence, there is no concrete evidence that industries promote sustainable development via CSR in Cameroon. The implementation of a sustainable business model is a precondition for promoting sustainable development via CSR. Industries should realize the concrete value in implementing a sustainable business model that helps to adjust to the complex and increasingly changing business environment.

  10. Community pico and micro hydropower for rural electrification: experiences from the mountain regions of Cameroon

    Directory of Open Access Journals (Sweden)

    Stefano Mandelli

    2016-02-01

    Full Text Available Less than 15% of rural areas of Cameroon have access to grid electricity. Only 53% of the population has access to grid electricity. Notwithstanding, Cameroon has a huge hydropower potential which could be harnessed. Mini grids, powered by pico and micro hydropower plants, are a relatively new rural electrification strategy in Cameroon. Several of such mini grids have been realized in the mountain regions of the country. Some of these systems have been more successful than others. This paper aims to share the experiences of community-based pico and micro hydropower schemes for rural electrification in Cameroon. The paper provides insight to the challenges that three of such mini grid systems powered by pico and micro hydropower plants had encountered and it attempts to identify issues related to their performances. The study was based on personal experience, field visits, participant observations, interviews and focus group discussions with key members of the beneficiary communities and documentations from the local NGO which implemented the schemes. Key findings of this study relate to the description of the main aspects about: planning of a robust system design, organizational aspects, like social cohesion at all levels of scheme management, community leadership and ownership of the system and involvement of the beneficiaries at all stages of the project cycle. These aspects were particularly addressed within the context of rural communities in Cameroon.

  11. Volcan Reventador's Unusual Umbrella

    Science.gov (United States)

    Chakraborty, P.; Gioia, G.; Kieffer, S. W.

    2005-12-01

    In the past two decades, field observations of the deposits of volcanoes have been supplemented by systemmatic, and sometimes, opportunistic photographic documentation. Two photographs of the umbrella of the December 3, 2002 eruption of Volcan Reventador, Ecuador, reveal a prominently scalloped umbrella that is unlike any umbrella previously documented on a volcanic column. The material in the umbrella was being swept off a descending pyroclastic flow, and was, therefore, a co-ignimbrite cloud. We propose that the scallops are the result of a turbulent Rayleigh-Taylor (RT) instability with no precedents in volcanology. We ascribe the rare loss of buoyancy that drives this instability to the fact that the Reventador column fed on a cool co-ignimbrite cloud. On the basis of the observed wavelength of the scallops, we estimate a value for the eddy viscosity of the umbrella of 4000 ~m2/s. This value is consistent with a previously obtained lower bound (200 ~m2/s, K. Wohletz, priv. comm., 2005). We do not know the fate of the material in the umbrella subsequent to the photos. The analysis suggests that the umbrella was negatively buoyant. Field work on the co-ignimbrite deposits might reveal whether or not the material reimpacted, and if so, where and whether or not this material was involved in the hazardous flows that affected the main oil pipeline across Ecuador.

  12. Uranium series, volcanic rocks

    Science.gov (United States)

    Vazquez, Jorge A.

    2014-01-01

    Application of U-series dating to volcanic rocks provides unique and valuable information about the absolute timing of crystallization and differentiation of magmas prior to eruption. The 238U–230Th and 230Th-226Ra methods are the most commonly employed for dating the crystallization of mafic to silicic magmas that erupt at volcanoes. Dates derived from the U–Th and Ra–Th methods reflect crystallization because diffusion of these elements at magmatic temperatures is sluggish (Cherniak 2010) and diffusive re-equilibration is insignificant over the timescales (less than or equal to 10^5 years) typically associated with pre-eruptive storage of nearly all magma compositions (Cooper and Reid 2008). Other dating methods based on elements that diffuse rapidly at magmatic temperatures, such as the 40Ar/39Ar and (U–Th)/He methods, yield dates for the cooling of magma at the time of eruption. Disequilibrium of some short-lived daughters of the uranium series such as 210Po may be fractionated by saturation of a volatile phase and can be employed to date magmatic gas loss that is synchronous with volcanic eruption (e.g., Rubin et al. 1994).

  13. Volcanic Eruptions and Climate

    Science.gov (United States)

    LeGrande, Allegra N.; Anchukaitis, Kevin J.

    2015-01-01

    Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.

  14. Current cancer incidence and trends in Yaounde, Cameroon

    Directory of Open Access Journals (Sweden)

    Enow Orock GE

    2014-05-01

    Full Text Available Background: Except for some information on relative frequencies of different cancers in selected areas, the epidemiology of cancer in Cameroon is relatively unknown. Though there is no reliable data on its incidence and pattern, with an estimated 15,000 new cases diagnosed annually and a prevalence of about 25.000 cases throughout the country, cancer is being increasingly recognized as a public health problem in Cameroon. The Yaounde Cancer Registry is a population registry physically located at the General Hospital Yaounde that has been operating since 2004. It collects data from about 20 sources that cover the entire population of Yaounde estimated in 2010 at about 1,299,369. Objectives: The objective of this study was to find out the incidence and trends of cancer in the Yaounde population in the period 2004 – 2006/2010 – 2011. It is hoped that this will enable policy makers, health providers and other stake holders plan appropriate health management policy in this population. Materials and Methods: This report presents the cancer incidence for 5 years, 2004 – 2006/2010 – 2011 in the Yaounde population estimated at 1,299,369. Data of the Yaounde Cancer Registry was reviewed for the period under study using Canreg5 software. Only malignant cases registered during the period under study were used in the analysis while benign and other uncertain tumours were excluded. The 2010 census estimates by the National Institute of Statistics was employed to calculate the incidence, age-standardized and crude rates. Other software like excel, epi info were also used for analysis. Survival studies were not carried out in this study. Results: A total of 4,689 new malignant cases were reported, of which 2,901 (68% were females and 1,788 (32% were males. The incidence showed an average of 358 for men and 580 for women. The average age of cancer patients in Yaounde is 44.8 years. Morphologically confirmed cases accounted for 89% .The annual number of

  15. Terrestrial volcanism in space and time

    Science.gov (United States)

    Simkin, Tom

    1993-01-01

    A survey is presented of current volcanic activity around the world and of dated volcanism over the past 10,000 yrs. The patterns in the data are described. The hazard presented by volcanism is briefly examined.

  16. ETINDE. Improving the role of a methodological approach and ancillary ethnoarchaeological data application for place vulnerability and resilience to a multi-hazard environment: Mt. Cameroon volcano case study [MIA-VITA project -FP7-ENV-2007-1

    Science.gov (United States)

    Ilaria Pannaccione Apa, Maria; Kouokam, Emmanuel; Mbe Akoko, Robert; Peppoloni, Silvia; Fabrizia Buongiorno, Maria; Thierry, Pierre

    2013-04-01

    The FP7 MIA-VITA [Mitigate and assess risk from volcanic impact on terrain and human activities] project has been designed to address multidisciplinary aspects of volcanic threat assessment and management from prevention to crisis management recovery. In the socio-economic analysis carried out at Mt. Cameroon Bakweri and Bakossi ethnic groups, ancillary ethnoarchaeological information has been included to point out the cultural interaction between the volcano and its residents. In 2009-2011, ethnoanthropological surveys and interviews for data collection were carried out at Buea, Limbe, West Coast, Tiko and Muyuka sub-divisions adjacent to Mt. Cameroon. One of the outstanding, results from the Bakweri and Bakossi cultural tradition study: natural hazards are managed and produced by supernatural forces, as: Epasa Moto, God of the Mountain (Mt. Cameroon volcano) and Nyango Na Nwana , Goddess of the sea (Gulf of Guinea). In the case of Mount Cameroon, people may seek the spirit or gods of the mountain before farming, hunting and most recently the undertaking of the Mount Cameroon annual race are done. The spirit of this mountain must be seek to avert or stop a volcanic eruption because the eruption is attributed to the anger of the spirit. Among the Northern Bakweri, the association of spirits with the mountain could also be explained in terms of the importance of the mountain to the people. Most of their farming and hunting is done on the Mountain. Some forest products, for instance, wood for building and furniture is obtained from the forest of the mountain; this implies that the people rely on the Mountain for food, game and architecture/furniture etc. In addition, the eruption of the mountain is something which affects the people. It does not only destroy property, it frustrates people and takes away human lives when it occurs. Because of this economic importance of the Mountain and its unexpected and unwanted eruption, the tendency is to believe that it has some

  17. The disease burden of Taenia solium cysticercosis in Cameroon.

    Directory of Open Access Journals (Sweden)

    Nicolas Praet

    Full Text Available BACKGROUND: Taenia solium cysticercosis is an important zoonosis in many developing countries. Human neurocysticercosis is recognised as an important cause of epilepsy in regions where the parasite occurs. However, it is largely underreported and there is a lack of data about the disease burden. Because a body of information on human and porcine cysticercosis in Cameroon is becoming available, the present study was undertaken to calculate the impact of this neglected zoonosis. METHODS: Both the cost and Disability Adjusted Life Year (DALY estimations were applied. All necessary parameters were collected and imported in R software. Different distributions were used according to the type of information available for each of the parameters. FINDINGS: Based on a prevalence of epilepsy of 3.6%, the number of people with neurocysticercosis-associated epilepsy was estimated at 50,326 (95% CR 37,299-65,924, representing 1.0% of the local population, whereas the number of pigs diagnosed with cysticercosis was estimated at 15,961 (95% CR 12,320-20,044, which corresponds to 5.6% of the local pig population. The total annual costs due to T. solium cysticercosis in West Cameroon were estimated at 10,255,202 Euro (95% CR 6,889,048-14,754,044, of which 4.7% were due to losses in pig husbandry and 95.3% to direct and indirect losses caused by human cysticercosis. The monetary burden per case of cysticercosis amounts to 194 Euro (95% CR 147-253. The average number of DALYs lost was 9.0 per thousand persons per year (95% CR 2.8-20.4. INTERPRETATION: This study provides an estimation of the costs due to T. solium cysticercosis using country-specific parameters and including the human as well as the animal burden of the zoonotic disease. A comparison with a study in South Africa indicates that the cost of inactivity, influenced by salaries, plays a predominant role in the monetary burden of T. solium cysticercosis. Therefore, knowing the salary levels and the

  18. Friction in volcanic environments

    Science.gov (United States)

    Kendrick, Jackie E.; Lavallée, Yan

    2016-04-01

    Volcanic landscapes are amongst the most dynamic on Earth and, as such, are particularly susceptible to failure and frictional processes. In rocks, damage accumulation is frequently accompanied by the release of seismic energy, which has been shown to accelerate in the approach to failure on both a field and laboratory scale. The point at which failure occurs is highly dependent upon strain-rate, which also dictates the slip-zone properties that pertain beyond failure, in scenarios such as sector collapse and pyroclastic flows as well as the ascent of viscous magma. High-velocity rotary shear (HVR) experiments have provided new opportunities to overcome the grand challenge of understanding faulting processes during volcanic phenomena. Work on granular ash material demonstrates that at ambient temperatures, ash gouge behaves according to Byerlee's rule at low slip velocities, but is slip-weakening, becoming increasingly lubricating as slip ensues. In absence of ash along a slip plane, rock-rock friction induces cataclasis and heating which, if sufficient, may induce melting (producing pseudotachylyte) and importantly, vesiculation. The viscosity of the melt, so generated, controls the subsequent lubrication or resistance to slip along the fault plane thanks to non-Newtonian suspension rheology. The shear-thinning behaviour and viscoelasticity of frictional melts yield a tendency for extremely unstable slip, and occurrence of frictional melt fragmentation. This velocity-dependence acts as an important feedback mechanism on the slip plane, in addition to the bulk composition, mineralogy and glass content of the magma, that all influence frictional behaviour. During sector collapse events and in pyroclastic density currents it is the frictional properties of the rocks and ash that, in-part, control the run-out distance and associated risk. In addition, friction plays an important role in the eruption of viscous magmas: In the conduit, the rheology of magma is integral

  19. Recurrence models of volcanic events

    International Nuclear Information System (INIS)

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Volcanism studies for the Yucca Mountain Site Characterization Project have progressed to a sufficient degree that it is now prudent to work toward concluding aspects of the work. An advantage of a probabilistic approach to volcanic risk is that it assigns a structured formalism to the problem. This formalism subdivides a complex issue into logical sections. The significance of uncertainty or differences in scientific opinion concerning volcanism issues can be tested for each section of a probabilistic problem. The perspective for making judgement of significance for volcanism studied are the regulatory requirements for assessing the suitability of the potential Yucca Mountain site. This paper attempts to begin the process of helping establish the probabilistic framework for making those judgement. There are three objectives. First, the authors describe the tripartite probability used to define the risk of volcanism and the geologic assumptions required for the probability model. Second, the authors examine and define the first part of this probability, the recurrence of volcanic events. Studies are reviewed from the volcanological literature where time-volume behavior of volcanic centers and fields have been evaluated. These evaluations include both conventional statistical analysis of time-series of volcanic events and applications using newly developing concepts of fractal analysis and deterministic chaos. Third, the authors tabulate past calculations and derive new values for the recurrence of volcanic events using a simple Poison model

  20. Analysis of the energy system of cameroon in a sustainable growth perspective

    International Nuclear Information System (INIS)

    After a decade of recession, Cameroon's economy returned to positive growth after 1995. Six years later, the country ran into an energy crisis featuring frequent power load shedding, liquefied gas shortages, declining oil production and fuel price increases. This crisis contributed to stagnation of the economy and to social disruption. Though the causes are primarily economic, in the case of power load shedding and gas shortages there are also structural and organisational problems. Who has control over the power operating systems is as a result a major issue for all players in the power area. This article analyses Cameroon's power system by reviewing the interacting socio-economic, environmental, technological and political actors and distinguishes structural from other influences. We show that Cameroon's current energy system is neither compatible with equitable economic and social growth objectives in time and space, nor with long term environmental objectives. The imbalance between energy supply and demand, currently in deficit, is critically assessed. (authors)

  1. Survey of gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in Southwestern Cameroon.

    Science.gov (United States)

    Matthews, Adele; Matthews, Andreas

    2004-01-01

    A study on the distribution and population density of the western lowland gorilla (Gorilla g. gorilla) and the central chimpanzee (Pan t. troglodytes) was undertaken between December 1997 and August 2000 in the Campo and Ma'an Forests in southwestern Cameroon. The aim of this survey was to estimate the densities of the apes in different parts of the area, to assess the importance of the region for the conservation of these endangered species and to determine the influence of human activities such as logging and hunting. The survey was based on night nest counts on a total of 665.5 km of line transects. The overall density in the Campo Forest was estimated at 0.2 gorillas/km(2) and at 0.63-0.78 chimpanzees/km(2). The overall density of chimpanzees in the Ma'an Forest was estimated at 0.8-1 individuals/km(2). Gorilla density in this area was too low to allow an estimation. The highest gorilla nest density was found in secondary forest. The gorilla density in unlogged forest was significantly lower. Chimpanzees showed a clear preference for less disturbed areas. In unlogged forest, old secondary forests (logging more than 23 years ago) and areas of recent logging with large remaining patches of primary forest, significantly higher densities were calculated than inside the more heavily exploited logging concession. In areas with both logging and high hunting pressure both species were rare or even absent. The Campo Ma'an area is considered a very important area for the conservation of gorillas and chimpanzees. Conservation measures are urgently required to reduce the impact of logging and hunting. The creation of the Campo Ma'an National Park in January 2000 is an important measure to preserve the unique biodiversity in this so far hardly protected area. PMID:14586801

  2. Infections among pygmies in the Eastern Province of Cameroon.

    Science.gov (United States)

    Ndumbe, P M; Atchou, G; Biwole, M; Lobe, V; Ayuk-Takem, J

    1993-12-01

    The health requirements of pygmies is poorly understood because of their continued isolation from the other tribes in Central Africa. This study was undertaken among the Baka pygmies of the Eastern Province of Cameroon to generate basic health data among them. A total of 141 adults (18-45 years) were tested for the hepatitis B surface antigen (HBsAg), antibody to the surface antigen (anti-HBs), antibody to the core antigen (anti-HBc) and antibody to the hepatitis C virus (anti-HCV). All HBsAg-positive sera were tested for the hepatitis B e antigen (HBeAg) and antibody (anti-HBe). The presence of antibodies to the hepatitis D virus was determined in most of the anti-Hbs-positive sera, and some of the HBsAg-positive sera. In addition to these, previous infection with syphilis, measles, HIV 1/2 and HTLV were determined by looking for the specific antibodies. We found HBsAg in 14.2% (20/141), anti-HBs in 93.6% (132/141), anti-HBs in 52.2% (73/140), anti-HCV in 7.9% (11/139, measles antibody in 99.3% (139/140), antibody to Treponema pallidum in 13.4% (18/134), antibody to HTLV-1 in 10.9% (15/138) and antibody to HIV-1 in 0.7% (1/140) of the sera tested.

  3. Natural Radioactivity in Some Commercial Bottled Waters in Cameroon

    International Nuclear Information System (INIS)

    The aim of this work was to check and determine the activity concentration of 40K, 226Ra and 228Ra in some commercial bottled water used as drinking water in Cameroon by means of using High-Purity Germanium based gamma spectrometry techniques. The water samples were firstly chemically treated by adding nitric acid and then pre-concentrated further by evaporating them up to a certain level. The water residues were transferred to small cylindrical containers and were kept sealed in order to ensure secular equilibrium between U-238, Th-232 and their daughter products. The calculated activity concentration for 226Ra (U-series) and 228Ra (Th-series) were used to estimate the annual effective doses for different age groups infants (age 1-2 years), children (age 7-12 years) and adults (age ≥17years) by taking into account the ingested dose conversion factors obtained from the International Commission on Radiological Protection (ICRP) as well as their yearly average bottled water consumption. The evaluated annual effective dose due to life-long consumption of water for different group ages where below the recommended values by WHO, IAEA and UNSCEAR. The paper presents the overview of the technique used and the summary of findings from this survey. (author)

  4. Indigenous Methods in Preserving Bush Mango Kernels in Cameroon

    Directory of Open Access Journals (Sweden)

    Zac Tchoundjeu

    2005-01-01

    Full Text Available Traditional practices for preserving Irvingia wombolu and Irvingia gabonensis (bush mango kernels were assessed in a survey covering twelve villages (Dongo, Bouno, Gribi [East], Elig-Nkouma, Nkom I, Ngoumou [Centre], Bidjap, Nko’ovos, Ondodo [South], Besong-Abang, Ossing and Kembong [Southwest], in the humid lowland forest zone of Cameroon. All the interviewed households that own trees of species were found to preserve kernels in periods of abundance, excluding Elig-Nkouma (87.5%. Eighty nine and 85% did so in periods of scarcity for I. wombolu and I. gabonensis respectively. Seventeen and twenty-nine kernel preservation practices were recorded for I. wombolu and I. gabonensis respectively. Most were based on continuous heating of the kernels or kernel by-products (cakes. The most commonly involved keeping the sun-dried kernels in a plastic bag on a bamboo rack hung above the fireplace in the kitchen. A 78% of interviews households reported preserving I. wombolu kernels for less than one year while 22% preserved it for more than one year with 1.9% for two years, the normal length of the off-season period for trees in the wild. Cakes wrapped with leaves and kept on a bamboo rack hung over the fireplace were reported by households in the East and South provinces to store Irvingia gabonensis longer (more than one year. Further studies on the utilization of heat for preserving and canning bush mango kernels are recommended.

  5. Access to Arable Land by Rural Women in Cameroon

    Directory of Open Access Journals (Sweden)

    Fon, DE.

    2011-01-01

    Full Text Available This study examines rural women access to and control of agricultural production resources in arable small-scale sustainable agricultural production in a developing country setting. Specifically, the study addresses the women's level of accessibility and control of arable land in agricultural production in the North West Region of Cameroon. The objectives of the study were: (a to determine the extent to which rural women in the study area gain access to and control small-scale arable land; and (b to assess the degree of association between access to small-scale arable land by rural women and their level of control of the arable land. The study relied on a one-shot case study design. The method of data collection consisted surveying a randomly selected sample of 1,120 rural women involved in small-scale agricultural production in the study area. The data obtained from the survey were analyzed using the following statistical procedures: (1 frequency distribution, (2 correlation analysis, and (3 one way analysis of variance (ANOVA. The results revealed that rural women farmers do have access to arable land through their families, but do not control arable land, and there is no association between access to and control of arable land. The study recommends that developing countries involved in arable small-scale agricultural production, should consider adopting agricultural policies that include rural women in decision-making, implementation, and evaluation of agricultural production inputs and outcomes.

  6. Seroprevalence of Toxoplasma gondii infection among pregnant women in Cameroon

    Directory of Open Access Journals (Sweden)

    Anna L. Njunda

    2011-09-01

    Full Text Available Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, which has a wide geographical distribution. The congenital form results in a gestational form that can present a temporary parasiteamia that will infect the fetus. For this reason early diagnosis in pregnancy is highly desirable, allowing prompt intervention in cases of infection. The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies among pregnant women attending the Douala General Hospital. The study was carried out between March and July 2009, whereby 110 pregnant women were tested for IgG and IgM antibodies and information about eating habits and hygienic conditions was collected using a questionnaire. These women’s ages ranged from 20-44 years old with an average of 29.9 years; the overall IgG and IgM seroprevalence was 70% and 2.73 % respectively. Seroprevalence was significantly high amongst women who ate raw vegetables (76.39%, P<0.05 and there was a significant trend towards a higher seroprevalence in women who did not have a good source of water (75.58%, P<0.05. This research showed that consumption raw vegetables and poor quality drinking water are two risk factors associated with Toxoplasma gondii infection amongst pregnant women attending the Douala General Hospital in Cameroon.

  7. [Descriptive study of cerebrovascular accidents in Douala, Cameroon].

    Science.gov (United States)

    Chiasseu, Mbeumi M T; Mbahe, S

    2011-10-01

    A cerebrovascular accident or stroke is a sudden-onset cerebral deficit of vascular origin lasting more than 24 hours. These events represent the second leading cause of death in the world and take a particularly heavy toll in third world countries. The purpose of this study was to describe cerebrovascular lesions (type, location, size) as well as patient age and gender in Cameroon. Brain CT-scan and MRI findings from 50 stroke patients admitted to two health centers in Douala were reviewed. Data showed that 74% of patients were over 50 years of age, the 51-60 year group being the most affected. Patients were male in 64% of cases. Ischemic stroke accounted for 60% of cases versus 40% for hemorrhagic stroke. The most affected sites were the sylvian territory site in ischemic stroke and the temporal lobe in hemorrhagic stroke, acconting for 43.3% and 35% of cases respectively. The median size of ischemic and hemorrhagic lesions were 2.81 cm3, and 26.98 cm3 respectively. Hemorrhagic stroke and lacunar infarcts were more common in this sample. Discrepancies between results at the two hospitals may be due to the use of different imaging techniques. Indeed, MRI is known to be more sensitive than CT-scan for acute detection of stroke lesions. PMID:22235625

  8. Compatibility of Schistosoma mansoni Cameroon and Biomphalaria pfeifferi Senegal.

    Science.gov (United States)

    Southgate, V R; Tchuenté, L A; Théron, A; Jourdane, J; Ly, A; Moncrieff, C B; Gryseels, B

    2000-11-01

    The vectorial capacity of Biomphalaria pfeifferi from Ndiangue, Senegal, was investigated with an allopatric isolate of Schistosoma mansoni from Nkolbisson, Cameroon. The snail infection rate after exposure to a single miracidium per snail (MD1) was 56. 3 %, and 91.6%, for snails exposed to 5 miracidia per snail (MD5). The minimum pre-patent period was 21 days. The mean total cercarial production for the MDI group was 18,511 cercariae per snail, and 9757 cercariae for the MD5 group. The maximum production of cercariae for 1 day was 4892 observed in a snail from the MDI group at day 43 post-infection. The mean longevity of snails was higher in group MD1 (88 days p.i.) than in group MD5 (65 days p.i.). The chronobiological emergence pattern revealed a circadian rhythm with one shedding peak at mid-day. Comparisons are made with the vectorial capacity of the sympatric combination of B. pfeifferi Senegal/S. mansoni Senegal.

  9. Seasonal pattern of hospitalization from acute respiratory infections in Yaoundé, Cameroon.

    Science.gov (United States)

    Tchidjou, Hyppolite Kuekou; Vescio, Fenicia; Boros, Stefano; Guemkam, Georgette; Minka, Esthelle; Lobe, Monny; Cappelli, Giulia; Colizzi, Vittorio; Tietche, Felix; Rezza, Giovanni

    2010-10-01

    Acute respiratory infections (ARIs) are among the leading causes of childhood morbidity and mortality in Africa. The effects of climatic factors on occurrence of ARIs in the tropics are not clear. During the years 2006-07, we reviewed the clinical registers of the Chantal Biya Foundation (CBF), Yaoundé, Cameroon, paediatric hospital to investigate the association between climatic factors and ARIs in children. Our findings show that rain, high relative humidity and low temperatures are directly associated with an increase in the frequency of hospitalization from ARIs. Given the high frequency of hospitalization from ARIs we suggest that influenza vaccination campaigns should be implemented taking into account the seasonality in Cameroon.

  10. Ethnomedicinal Plants Used by Traditional Healers to Treat Oral Health Problems in Cameroon

    OpenAIRE

    Michael Ashu Agbor; Sudeshni Naidoo

    2015-01-01

    Objectives. The objective of the study was to determine the therapeutic methods used by traditional healers to treat oral diseases in Cameroon. Methods. A total of 200 traditional healers with a mean age of 50.4 ± 14.2 years from all the provinces of Cameroon were studied using questionnaires. Information elicited was the local names of the medicinal plants used for the management of oral problems, their routes of administration, and methods of usage. Identification of live or dried plants or...

  11. Closer look at lunar volcanism

    International Nuclear Information System (INIS)

    Although the American Apollo and Soviet Luna missions concentrated on mare basalt samples, major questions remain about lunar volcanism. Lunar field work will be indispensable for resolving the scientific questions about ages, compositions, and eruption processes of lunar volcanism. From a utilitarian standpoint, a better knowledge of lunar volcanism will also yield profitable returns in lunar base construction (e.g., exploitation of rille or lava-tube structures) and in access to materials such as volatile elements, pure glass, or ilmenite for lunar industry

  12. Io. [theories concerning volcanic activity

    Science.gov (United States)

    Johnson, T. V.; Soderblom, L. A.

    1983-01-01

    A report on the continuing investigation of Io is presented. Gravitational resonance is discussed as the cause of Io's volcanism, and the volcanic activity is explained in terms of sulfur chemistry. Theories concerning the reasons for the two main types of volcanic eruptions on Io are advanced and correlated with geographical features of the satellite. The sulfur and silicate models of the calderas are presented, citing the strengths and weaknesses of each. Problems of the gravitational resonance theory of Io's heat source are then described. Finally, observations of Io planned for the Galileo mission are summarized.

  13. Hawaii Volcanism: Lava Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the last several million years the Hawaiian Islands have been built of successive lava flows. They are the most recent additions in a long line of volcanoes...

  14. Volcanology: Volcanic bipolar disorder explained

    Science.gov (United States)

    Jellinek, Mark

    2014-02-01

    Eruptions come in a range of magnitudes. Numerical simulations and laboratory experiments show that rare, giant super-eruptions and smaller, more frequent events reflect a transition in the essential driving forces for volcanism.

  15. Volcanic Zone, New Zealand

    Directory of Open Access Journals (Sweden)

    Graham J. Weir

    2001-01-01

    Full Text Available A conceptual model of the Taupo Volcanic Zone (TVZ is developed, to a depth of 25 km, formed from three constant density layers. The upper layer is formed from eruption products. A constant rate of eruption is assumed, which eventually implies a constant rate of extension, and a constant rate of volumetric creation in the middle and bottom layers. Tectonic extension creates volume which can accomodate magmatic intrusions. Spreading models assume this volume is distributed throughout the whole region, perhaps in vertical dykes, whereas rifting models assume the upper crust is thinned and the volume created lies under this upper crust. Bounds on the heat flow from such magmatic intrusions are calculated. Heat flow calculations are performed and some examples are provided which match the present total heat output from the TVZ of about 4200 MW, but these either have extension rates greater than the low values of about 8 ± 4 mm/a being reported from GPS measurements, or else consider extension rates in the TVZ to have varied over time.

  16. Volcanic eruptions observed with infrasound

    Science.gov (United States)

    Johnson, Jeffrey B.; Aster, Richard C.; Kyle, Philip R.

    2004-07-01

    Infrasonic airwaves produced by active volcanoes provide valuable insight into the eruption dynamics. Because the infrasonic pressure field may be directly associated with the flux rate of gas released at a volcanic vent, infrasound also enhances the efficacy of volcanic hazard monitoring and continuous studies of conduit processes. Here we present new results from Erebus, Fuego, and Villarrica volcanoes highlighting uses of infrasound for constraining quantitative eruption parameters, such as eruption duration, source mechanism, and explosive gas flux.

  17. Seasonal variations of surface duct conditions in Ngaoundere, North Cameroon

    Science.gov (United States)

    Kaissassou, Samuel; Lenouo, André; Nzeukou, Armand; Tchawoua, Clément; Vondou, D. A.

    2015-12-01

    The seasonal variations of refractivity gradients from 104 to 3000 m above ground level in the troposphere layer are presented based on observations from the radiosonde station located in Ngaoundere (13.5°E, 7.3°N), a middle belt savannah region of Cameroon. Six years (2006-2011) of data from in situ measurements made by Agency for the Safety of Air Navigation in Africa and Madagascar (ASECNA) of the temperature, moisture, and pressure are used to determine the surface duct conditions over Ngaoundere region. Each time that a negative gradient from the Abel-retrieved refractivity profiles is seen, it implies the presence of a duct in this study. The occurrence of ducts strongly depends on the local climate and synoptic weather conditions which have an appreciable influence on the refractivity vertical profile, especially the seasonal north-south movement of the Inter Tropical Convergence Zone (ITCZ) which provides wet and dry seasons to the region. Monthly and seasonal variations of ducts were also determined from the measured data. The highest and the lowest occurrence rate of surface ducts were observed during the wet and the dry seasons, respectively. September appears as the month when most of the ducts occur at the rate of at least one duct per day. The median duct thickness and duct strength are high and strong during the wet season, whereas they are low and weak during the dry season. When the data are separated into stable and unstable atmospheric conditions, we noticed that surface duct characteristics show some seasonal differences. Surface ducts are found to be more frequent in a stable atmosphere than in an unstable atmosphere. Statistical results are discussed alongside with local meteorological conditions and weather systems affecting the town of Ngaoundere. Besides, comments are made on their prospective significance in the region.

  18. [Epidemiology of obesity in the work milieu, Douala, Cameroon].

    Science.gov (United States)

    Fouda, A A Bita; Lemogoum, D; Manga, J Owona; Il Dissongo, J; Tobbit, R; Moyo, D F Ngounou; Sume, G Etapelong; Kollo, B

    2012-01-01

    Obesity is a worldwide public health problem, and its burden has been poorly explored in Cameroon, especially in work place. We therefore carried out in April 2010, an analytic cross-sectional study aiming to determine the prevalence of obesity, associated risk factors and health risk in six randomly selected enterprises based in Douala. Among the 552 participants, 383 (69.4%) were males. Most of the workers (55.4%) were aged less than 35 years old. There was 191 (34.60%) office staff as against 361 (65.40%) labourers. In each participant, blood pressures, and fasting blood glucose were recorded, as well as obesity indexes comprising body mass index and waist circumference. They were calculated and data analyzed using SPSS 16 and Win Pepi 11.8. The prevalence of obesity in workers was 23.4%, and was more pronounced in women than in men (36.1% vs 17.8%; P or = 45 years old exhibited highest obesity rate than other age group (P = 0.03). Importantly, the prevalence of hypertension was two fold greater in obese workers than non obese (P 88 cm and 41 (31.8%) men with a waist circumference > 102 cm were at very high health risk. Obesity was significantly associated with excessive alcohol consumption (P = 0.013) and high salt diet (P = 0.022). This study reveals a high burden of obesity in the work place in Douala and outlines the urgent needs of implementation of prevention programme in that milieu. PMID:22891584

  19. How to win a football match in Cameroon : an anthropological study of Africa's most popular sport

    NARCIS (Netherlands)

    Pannenborg, A.

    2008-01-01

    Footballers Essomba and Ashu, team manager Kalla and spiritual adviser Zé are the key characters in this anthropological study of football in Cameroon, which is based on research carried out in 2003. It might seem that a well-organized club with professional executives, a team of talented players an

  20. Neuropeltis eladii (Convolvulaceae), a new species from the South Province of Cameroon

    NARCIS (Netherlands)

    Breteler, F.J.

    2014-01-01

    Background and aims - The paleotropical genus Neuropeltis of the Convolvulaceae was recently treated in a synopsis for the African continent (Breteler 2010), counting nine species. This number is now enlarged by a new, overlooked, species from the South Province of Cameroon. Methods - Normal practic

  1. Lolodorfus, a new genus of net-winged beetles (Coleoptera: Lycidae: Dexorinae) from Cameroon.

    Science.gov (United States)

    Bocakova, Milada

    2014-06-04

    A new genus Lolodorfus is proposed within the subfamily Dexorinae and Lolodorfus flavus sp. nov. from Cameroon is described. Illustrations of diagnostic characters are given. The genus Mimolibnetis Pic, 1936 is transferred to the Dexorinae Bocak et Bocakova, 1989, and consequently the subfamily Mimolibnetinae Kazantsev, 2013 is considered to be a younger synonym of Dexorinae Bocak et Bocakova, 1989.

  2. Vulnerability, forest-related sectors and climate change adaptation : the case of Cameroon

    NARCIS (Netherlands)

    Sonwa, D.J.; Somorin, O.A.; Jum, C.; Bele, M.Y.; Nkem, J.N.

    2012-01-01

    In Cameroon and elsewhere in the Congo Basin, the majority of rural households and a large proportion of urban households depend on plant and animal products from the forests to meet their nutritional, energy, cultural and medicinal needs. This paper explores the likely impacts of climate-induced ch

  3. Gender and plantation labour in Africa : the story of tea pluckers' struggles in Cameroon

    NARCIS (Netherlands)

    Konings, P.J.J.

    2012-01-01

    This book explores the relationship between plantation labour and gender in Africa, particularly Cameroon. It demonstrates that the introduction of plantation labour during colonial rule has had significant consequences for gender roles and relations within and beyond the capitalist labour process.

  4. The post-colonial State and economic and political reforms in Cameroon

    NARCIS (Netherlands)

    Konings, P.J.J.; Fernández Jilberto, A.E.; Mommen, A.

    1996-01-01

    This study shows that the neoliberal project propagated in the 1990s by the Western donors and the international financial institutions has not yet made much progress in Cameroon. It argues that this is not surprising, given the class character of the Cameroonian postcolonial State. The limited poli

  5. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their st

  6. Tracing the origins of rescued chimpanzees reveals widespread chimpanzee hunting in Cameroon

    OpenAIRE

    Gadsby Elizabeth L; Fotso Roger; de Vries Simone; Akih Akih E; Kiyang John A; Lankester Felix; Ghobrial Lora; Jenkins Peter D; Gonder Mary K

    2010-01-01

    Abstract Background While wild chimpanzees are experiencing drastic population declines, their numbers at African rescue and rehabilitation projects are growing rapidly. Chimpanzees follow complex routes to these refuges; and their geographic origins are often unclear. Identifying areas where hunting occurs can help law enforcement authorities focus scarce resources for wildlife protection planning. Efficiently focusing these resources is particularly important in Cameroon because this countr...

  7. The politics of neoliberal reforms in Africa : State and civil society in Cameroon

    NARCIS (Netherlands)

    Konings, P.J.J.

    2011-01-01

    Neoliberalism has become the dominant development agenda in Africa, but neoliberal experiments have displayed a remarkable diversity in different countries. This book focuses on Cameroon, where the neoliberal project has been influenced by the nation's complex economic and political history. Current

  8. Distribution, incidence and abundance of the cassava brown root scale insect, Stictococcus vayssierei, in Cameroon

    NARCIS (Netherlands)

    Tchuanyo, M.; Huis, van A.; Lenteren, van J.C.

    2000-01-01

    A new scale insect, Stictococcus vayssierei, has been found attacking all the underground parts of cassava. From surveys in all the cassava-growing areas of Cameroon, the insect seems to be limited to the southern part of the country, where it is a major pest of cassava. This is the semi-humid zone

  9. Fish Pond Aquaculture in Cameroon: A Field Survey of Determinants for Farmers' Adoption Behaviour

    Science.gov (United States)

    Ndah, Hycenth Tim; Knierim, Andrea; Ndambi, Oghaiki Asaah

    2011-01-01

    Although fish farming in Cameroon started in the late 1940s, currently the country meets only half of its domestic demand for fish. This article examines the complex issue of farmers' adoption decisions and attempts to answer why there is a lag in the diffusion process. The theory of behaviour modification and key variables of adoption form the…

  10. Farmer's perception of the effects of eartworms on soil fertility and crop performance in southern Cameroon

    NARCIS (Netherlands)

    Madong à Birang,; Hauser, S.; Amougou, D.L.

    2003-01-01

    The knowledge and perception of the effects of earthworms on soil fertility and crop growth was surveyed in a humid forest zone of southern Cameroon. A total of 215 farmers were interviewed in seven villages: two villages were near the capital Yaounde, severely deforested with a high land-use intens

  11. The Position of English Globally and Nationally: A Comparison of Cameroon and Vanuatu

    Science.gov (United States)

    Abongdia, Jane-Francis A.; Willans, Fiona

    2014-01-01

    This paper investigates language ideologies relevant to medium of instruction policy within two postcolonial countries: Cameroon and Vanuatu. Each country experienced British and French rule, and has retained both English and French as official languages and media of instruction. However, since Independence, there has been a difference in the way…

  12. Fungi from the Dja Biosphere Reserve (Cameroon). Notes on some Gasteromycetes.

    OpenAIRE

    Calonge, F.D.; Daniëls, P.P

    1998-01-01

    [EN] Four species of Gasteromycetes collected in the Biosphere Reserve of Dja (Cameroon), are briefly described and commented. Two of them: Cyathus striatus and Sphaerobolus stellatus are well-known in Europe, being cosmopolitan, and the other two: Geastrum schweinitzii var. stipitatum and Phallus indusiatus show a typical pantropical distribution.

  13. Modern bioenergy from agricultural and forestry residues in Cameroon: Potential, challenges and the way forward

    DEFF Research Database (Denmark)

    Ackom, Emmanuel; Alemagi, Dieudonne; Ackom, Nana B.;

    2013-01-01

    Environmentally benign modern bioenergy is widely acknowledged as a potential substitute for fossil fuels to offset the human dependence on fossil fuels for energy. We have profiled Cameroon, a country where modern bioenergy remains largely untapped due to a lack of availability of biomass data a...

  14. The emotional world of kinship: Children's experiences of fosterage in East Cameroon

    NARCIS (Netherlands)

    Notermans, C.D.

    2008-01-01

    This article focuses on children's narrated experiences of fosterage in East Cameroon. It seeks to complement the predominantly adult approaches to fosterage with children's views of the intimate, emotional and competitive aspects of kinship in everyday life. As kinship evolves in homes through shar

  15. Bridging the gap: how traditional healers interact with their patients. A comparative study in Cameroon.

    NARCIS (Netherlands)

    Labhardt, N.D.; Aboa, S.M.; Manga, E.; Bensing, J.M.; Langewitz, W.

    2010-01-01

    Objective: To compare traditional healers (TH) and Cameroonian representatives of Western medicine (Western providers (WP)) in terms of patient characteristics and communication patterns during the consultation in rural Cameroon. Methods: A facility-based comparative study was conducted. Seven TH we

  16. An Emerging Donor in Education and Development: A Case Study of China in Cameroon

    Science.gov (United States)

    Nordtveit, Bjorn H.

    2011-01-01

    This paper analyzes China's new approaches of education aid to Africa through a case study of Cameroon. China's cooperation has been characterized by different discourses and different historic relationships with recipient countries than those of traditional donors. Sino-African policies have gone through different stages, each connected to wider…

  17. Instructors' Perceptions of the Bologna Model of Higher Education Reform in Cameroon

    Science.gov (United States)

    Mngo, Zachary Y.

    2011-01-01

    Problem Statement. The literature on education in Cameroon suggests that there is a deep-rooted history of resistance to educational reform and harmonization both at the K12 and higher education levels. Attempts by political and educational leaders to reform and harmonize the two very distinct systems of education, inherited from former colonizers…

  18. Meckel's diverticulum: a case report from the University Hospital Center Yaoundé, Cameroon

    Directory of Open Access Journals (Sweden)

    Arthur Essomba

    2009-10-01

    Full Text Available To the best of our knowledge there is no reported case of Meckel's diverticulum (MD in Cameroon. The prevalence of MD in the general population is 2-3 %. The aim of this paper is to recapitulate the role of this pathology in acute abdomens and abdominal pain of uncertain aetiology in young patients and to review the medical literature.

  19. Language Ideology and the Colonial Legacy in Cameroon Schools: A Historical Perspective

    Science.gov (United States)

    Nana, Genevoix

    2016-01-01

    Cameroon prior to colonization had many languages, with none having precedence over the other. With the development of trade and the installation of missionaries along its coast, a number of local and European languages gained prominence. English became the most widely used western language. It established itself as the language of trade and of…

  20. Learner Orientation through Professional Development of Teachers? Empirical Results from Cascade Training in Anglophone Cameroon

    Science.gov (United States)

    Lange, Sarah

    2014-01-01

    This paper examines the effects of a professional development programme on the attitudes towards the teaching and learning of teachers in the Anglophone part of Cameroon. The development programme combines a multiplier system with school-based in-service training. The research compares the effects that the training had on the attitudes of three…

  1. Implications of Local Literacy Practices for Literacy Programmes in a Multilingual Community in Northern Cameroon

    Science.gov (United States)

    Cheffy, Ian

    2011-01-01

    Research in a rural area of northern Cameroon where most adults describe themselves as illiterate reveals a complex picture in which three languages are used in different ways and in different domains of life. The profile of the literacy practices associated with these languages is correspondingly complex. This paper argues that it is important…

  2. 78 FR 76698 - Waiver of Restriction on Assistance to the Central Government of Cameroon

    Science.gov (United States)

    2013-12-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Waiver of Restriction on Assistance to the Central Government of Cameroon Pursuant to Section 7031(b)(3) of... Section 7031(b)(1) of the Act and similar provisions of law in prior year Acts with respect to...

  3. The Emotional World of Kinship: Children's Experiences of Fosterage in East Cameroon

    Science.gov (United States)

    Notermans, Catrien

    2008-01-01

    This article focuses on children's narrated experiences of fosterage in East Cameroon. It seeks to complement the predominantly adult approaches to fosterage with children's views of the intimate, emotional and competitive aspects of kinship in everyday life. As kinship evolves in homes through sharing food and intimacy, children directly…

  4. Buruli Ulcer in Cameroon: The Development and Impact of the National Control Programme.

    Directory of Open Access Journals (Sweden)

    Earnest Njih Tabah

    2016-01-01

    Full Text Available Cameroon is endemic for Buruli ulcer (BU and organised institutional BU control began in 2002. The objective was to describe the evolution, achievements and challenges of the national BU control programme (NBUCP and to make suggestions for scaling up the programme.We analysed collated data on BU from 2001 to 2014 and reviewed activity reports NBUCP in Cameroon. Case-detection rates and key BU control indicators were calculated and plotted on a time scale to determine trends in performance. A linear regression analysis of BU detection rate from 2005-2014 was done. The regression coefficient was tested statistically for the significance in variation of BU detection rate.In 14 years of BU control, 3700 cases were notified. The BU detection rate dropped significantly from 3.89 to 1.45 per 100 000 inhabitants. The number of BU endemic health districts rose from two to 64. Five BU diagnostic and treatment centres are functional and two more are planned for 2015. The health system has been strengthened and BU research and education has gained more interest in Cameroon.Although institutional BU control Cameroon only began 30 years after the first cases were reported in 1969, a number of milestones have been attained. These would serve as stepping stones for charting the way forward and improving upon control activities in the country if the major challenge of resource allocation is dealt with.

  5. Parentage analysis and outcrossing patterns in cacao (Theobroma cacao L.) farms in Cameroon

    Science.gov (United States)

    The present study investigates the parentage of farm accessions in Cameroon using data from 12 microsatellite loci. Bayesian analysis suggests that 25.5% of the 400 farm accessions studies are still closely related to the traditinal Amelonado variety called 'German Cocoa' by the farmers. Another 46....

  6. Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

    NARCIS (Netherlands)

    Kanmegne, J.; Smaling, E.M.A.; Brussaard, L.; Gansop-Kouomegne, A.; Boukung, A.

    2006-01-01

    The flows and balances of N, P and K were studied in 20 farms in the Campo Ma'an area in Cameroon between March and August 2002 to assess the nutrient dynamics in smallholder farms. Data were collected through farmer interviews, field measurements and estimates from transfer functions. Nutrient inpu

  7. Determinants and Impacts Of Human Mobility Dynamics In The Western Highlands Of Cameroon

    NARCIS (Netherlands)

    Tankou, C.M.; Iongh, de H.H.; Persoon, G.; Bruijn, de M.E.; Snoo, de G.R.

    2014-01-01

    This study analyses human mobility among inhabitants of Cameroon‘s most populous region, the Western Highlands of Cameroon. In other to capture the impact of various determinants on human mobility, a comparative study was conducted through household and field surveys in three villages in the region

  8. Teaching Practice in Cameroon: The Effectiveness of the University of Buea Model and Implications for Quality

    Science.gov (United States)

    Endeley, Margaret Nalova

    2014-01-01

    The paper aimed at assessing the effectiveness of the teaching practice model in the University of Buea, which is different from that of other teacher education institutions in Cameroon. Teaching Practice is an important component of a teacher education programme and the quality of supervision and duration are key in achieving effectiveness which…

  9. Adelonema camerunense gen. et sp. n. (Araeolaimida: Diplopeltidae) from rain forest in Cameroon

    NARCIS (Netherlands)

    Holovachov, O.V.; Sturhan, D.

    2003-01-01

    Adelonema camerunense gen. et sp. n. (Araeolaimida: Diplopeltidae) from rain forest in Cameroon is described on the basis of light microscopy. The new genus is tentatively placed in the Diptopeltidae and distinguished from all other genera in the family by the following characters: cuticle with ten

  10. Floodplain rehabilitation in Far North Cameroon: expected impact on bird life

    NARCIS (Netherlands)

    Scholte, P.; Kort, de S.; Weerd, van M.

    2000-01-01

    The Logone floodplain in the sahelo-Sudanian zone of Cameroon used to be a highly productive ecosystem. Perennial pastures and fish played a crucial role for fishermen, pastoralists and wildlife. The construction of an upstream dam reduced inundation causing widespread degradation Nonetheless, appro

  11. Dieback due to Lasiodiplodia theobromae, a new phytosanitary constraint to cocoa culture in Cameroon.

    Science.gov (United States)

    Since the introduction of cocoa (Theobroma cacao L.) in Cameroon in 1886, the only serious disease has been Phytophthora pod rot. Recently, cocoa orchards have been subjected to an increasingly important decline due to an uncommon dieback disease. Irrespective of age, affected cocoa trees manifest ...

  12. Access to potable water and sanitation in Cameroon within the context of Millennium Development Goals (MDGS).

    Science.gov (United States)

    Ako, Andrew Ako; Shimada, Jun; Eyong, Gloria Eneke Takem; Fantong, Wilson Yetoh

    2010-01-01

    Cameroon has been fully engaged with the Millennium Development Goals (MDGs) since their inception in 2000. This paper examines the situation of access to potable water and sanitation in Cameroon within the context of the Millennium Development Goals (MDGs), establishes whether Cameroon is on the track of meeting the MDGs in these domains and proposes actions to be taken to bring it closer to these objectives. Based on analyzed data obtained from national surveys, government ministries, national statistical offices, bibliographic research, reports and interviews, it argues that Cameroon will not reach the water and sanitation MGDs. While Cameroon is not yet on track to meet the targets of the MDGs for water and sanitation, it has made notable progress since 1990, much more needs to be done to improve the situation, especially in rural areas. In 2006, 70% of the population had access to safe drinking water and the coverage in urban centres is 88%, significantly better than the 47% in rural areas. However, rapid urbanization has rendered existing infrastructure inadequate with periurban dwellers also lacking access to safe drinking water. Sanitation coverage is also poor. In urban areas only 58% of the population has access to improved sanitation facilities, and the rate in rural areas is 42%. Women and girls shoulder the largest burden in collecting water, 15% of urban and 18% rural populations use improved drinking water sources over 30 minutes away. Cameroon faces the following challenges in reaching the water and sanitation MDGs: poor management and development of the resources, coupled with inadequate political will and commitment for the long term; rapid urbanization; urban and rural poverty and regulation and legislative lapses. The authors propose that: bridging the gap between national water policies and water services; recognizing the role played by Civil Society Organizations (CSOs) in the attainment of MDGs; developing a Council Water Resource Management

  13. A Critical Appraisal of the Juvenile Justice System under Cameroon's 2005 Criminal Procedure Code: Emerging Challenges

    Directory of Open Access Journals (Sweden)

    S Tabe

    2012-03-01

    Full Text Available The objective of this article is to examine the changes introduced by the 2005 Cameroonian Criminal Procedure Code on matters of juvenile justice, considering that before this Code, juvenile justice in Cameroon was governed by extra-national laws. In undertaking this analysis, the article highlights the evolution of the administration of juvenile justice 50 years after independence of Cameroon. It also points out the various difficulties and shortcomings in the treatment of juvenile offenders in Cameroon since the enactment of the new Criminal Procedure Code. The article reveals that the 2005 Code is an amalgamation of all hitherto existing laws in the country that pertained to juvenile justice, and that despite the considerable amount of criticism it has received, the Code is clearly an improvement of the system of juvenile justice in Cameroon, since it represents a balance of the due process rights of young people, the protection of society and the special needs of young offenders. This is so because the drafters of the Code took a broad view of the old laws on juvenile justice. Also a wide range of groups were consulted, including criminal justice professionals, children’s service organisations, victims, parents, young offenders, educators, advocacy groups and social-policy analysts. However, to address the challenges that beset the juvenile justice system of Cameroon, the strategy of the government should be focussed on three areas: the prevention of youth crime, the provision of meaningful consequences for the actions of young people, and the rehabilitation and reintegration of young offenders. Cameroonian law should seek educative solutions rather than to impose prison sentences or other repressive measures on young offenders. Special courts to deal with young offenders should be established outside the regular penal system and should be provided with resources that are adequate for and appropriate to fostering their understanding of

  14. Geochemical Interpretation of Collision Volcanism

    Science.gov (United States)

    Pearce, Julian

    2014-05-01

    Collision volcanism can be defined as volcanism that takes place during an orogeny from the moment that continental subduction starts to the end of orogenic collapse. Its importance in the Geological Record is greatly underestimated as collision volcanics are easily misinterpreted as being of volcanic arc, extensional or mantle plume origin. There are many types of collision volcanic province: continent-island arc collision (e.g. Banda arc); continent-active margin collision (e.g. Tibet, Turkey-Iran); continent-rear-arc collision (e.g. Bolivia); continent-continent collision (e.g. Tuscany); and island arc-island arc collision (e.g. Taiwan). Superimposed on this variability is the fact that every orogeny is different in detail. Nonetheless, there is a general theme of cyclicity on different time scales. This starts with syn-collision volcanism resulting from the subduction of an ocean-continent transition and continental lithosphere, and continues through post-collision volcanism. The latter can be subdivided into orogenic volcanism, which is related to thickened crust, and post-orogenic, which is related to orogenic collapse. Typically, but not always, collision volcanism is preceded by normal arc volcanism and followed by normal intraplate volcanism. Identification and interpretation of collision volcanism in the Geologic Record is greatly facilitated if a dated stratigraphic sequence is present so that the petrogenic evolution can be traced. In any case, the basis of fingerprinting collision terranes is to use geochemical proxies for mantle and subduction fluxes, slab temperatures, and depths and degrees of melting. For example, syn-collision volcanism is characterized by a high subduction flux relative to mantle flux because of the high input flux of fusible sediment and crust coupled with limited mantle flow, and because of high slab temperatures resulting from the decrease in subduction rate. The resulting geochemical patterns are similar regardless of

  15. Automatic landslides detection on Stromboli volcanic Island

    Science.gov (United States)

    Silengo, Maria Cristina; Delle Donne, Dario; Ulivieri, Giacomo; Cigolini, Corrado; Ripepe, Maurizio

    2016-04-01

    Landslides occurring in active volcanic islands play a key role in triggering tsunami and other related risks. Therefore, it becomes vital for a correct and prompt risk assessment to monitor landslides activity and to have an automatic system for a robust early-warning. We then developed a system based on a multi-frequency analysis of seismic signals for automatic landslides detection occurring at Stromboli volcano. We used a network of 4 seismic 3 components stations located along the unstable flank of the Sciara del Fuoco. Our method is able to recognize and separate the different sources of seismic signals related to volcanic and tectonic activity (e.g. tremor, explosions, earthquake) from landslides. This is done using a multi-frequency analysis combined with a waveform patter recognition. We applied the method to one year of seismic activity of Stromboli volcano centered during the last 2007 effusive eruption. This eruption was characterized by a pre-eruptive landslide activity reflecting the slow deformation of the volcano edifice. The algorithm is at the moment running off-line but has proved to be robust and efficient in picking automatically landslide. The method provides also real-time statistics on the landslide occurrence, which could be used as a proxy for the volcano deformation during the pre-eruptive phases. This method is very promising since the number of false detections is quite small (detection as an improving tool for early warnings of tsunami-genic landslide activity. We suggest that a similar approach could be also applied to other unstable non-volcanic also slopes.

  16. Delineation of a volcanic ash body using electrical resistivity profiling

    International Nuclear Information System (INIS)

    Four lines of electrical resistivity profiling (ERP) were performed to define the extent of a shallow Quaternary volcanic ash deposit being mined in the United States. Inversion results of ERP proved suitable for defining the thickness and lateral extent of the volcanic ash deposit at this testing site. These interpretations were confirmed by shallow borehole drilling. The model sensitivity information indicates that inverted models possess sufficient resolving power down to a depth of 7 m and are fairly consistent in terms of horizontal resolution along the four ERP lines. The bottom of most of the volcanic ash deposit in the study area is less than 7 m in depth. Based on synthesis of the ERP and drill information, the limits of the mineable ash bed resources were clearly defined. Moreover, by integrating the ERP results with a minimal number of optimally placed borings, the volume of the volcanic ash deposit was established at a lesser cost, and with greater accuracy than would be possible with a traditionally designed grid drilling programme

  17. Farmers knowledge and perception on maize stem borers and their indigenous control methods in south western region of Cameroon

    OpenAIRE

    Oben, Esther Obi; Ntonifor, Nelson Neba; Kekeunou, Sevilor; Abbeytakor, Martin Nkwa

    2015-01-01

    Background Agriculture is a major contributor to the Gross Domestic Product (GDP) of Cameroon, The South West region of Cameroon is known for its potential in the production of major agricultural commodities, but farmers’ yields from various speculations are low, dwindling over time due to some major constraints. Maize production is hampered by adverse socio-economic factors, several pests and diseases as well as high rainfall with low solar radiation. Lepidopterous maize stem borers are a ma...

  18. Spatial and Inter-temporal Sources of Poverty, Inequality and Gender Disparities in Cameroon: a Regression-Based Decomposition Analysis

    OpenAIRE

    Boniface Ngah Epo; Francis Menjo Baye; Nadine Teme Angele Manga

    2011-01-01

    This study applies the regression-based inequality decomposition technique to explain poverty and inequality trends in Cameroon. We also identify gender related factors which explain income disparities and discrimination based on the 2001 and 2007 Cameroon household consumption surveys. The results show that education, health, employment in the formal sector, age cohorts, household size, gender, ownership of farmland and urban versus rural residence explain household economic wellbeing; dispa...

  19. Primary care physicians’ practice regarding diabetes mellitus diagnosis, evaluation and management in the West region of Cameroon

    OpenAIRE

    Jingi, Ahmadou M.; Nansseu, Jobert Richie N; Jean Jacques N Noubiap

    2015-01-01

    Background Primary care physicians (PCPs) are the main providers of diabetes care especially in resource-limited countries which experience extreme shortage of specialists. The present study aimed to evaluate PCPs’ approach towards diabetes mellitus (DM) diagnosis, evaluation and management in Cameroon. Methods We carried-out a cross-sectional survey in February 2012 in the West Region of Cameroon. Using a structured pretested questionnaire, we interviewed all PCPs working in the region who w...

  20. Pattern of non-obstetric infectious recto-vaginal fistula: a case series and literature review in Cameroon, Central Africa

    OpenAIRE

    Pierre Marie Tebeu; Roger Guy Michel Ekono; Jovanny Tsuala Fouogue; Gregory Ekane Halle; Joel Domgue Fokom; Charles Henry Rochat

    2016-01-01

    Background: Perineal infection is an uncommon cause of non-obstetrical recto-vaginal fistula (RVF) which is associated with HIV infection. Cameroon (Central Africa) is in the fistula belt but infectious RVFs have not yet been deeply studied in the country. We therefore sought to determine the pattern of non-obstetric infectious RVF in Cameroon. Methods: We carried out a cross-sectional and descriptive review of non-obstetric infectious RVFs managed at the Yaound and eacute; University Teac...

  1. On water in volcanic clouds

    Science.gov (United States)

    Durant, Adam J.

    2007-12-01

    Volcanic clouds and tephra fallout present a hazard to aviation, human and animal health (direct inhalation or ingestion, contamination of water supplies), and infrastructure (building collapse, burial of roads and railways, agriculture, abrasive and chemical effects on machinery). Understanding sedimentation processes is a fundamental component in the prediction of volcanic cloud lifetime and fallout at the ground, essential in the mitigation of these hazards. The majority of classical volcanic ash transport and dispersion models (VATDM) are based solely on fluid dynamics. The non-agreement between VATDM and observed regional-scale tephra deposit characteristics is especially obvious at large distances from the source volcano. In meteorology, the processes of hydrometeor nucleation, growth and collection have been long-established as playing a central role in sedimentation and precipitation. Taking this as motivation, the hypothesis that hydrometeor formation drives sedimentation from volcanic clouds was tested. The research objectives of this dissertation are: (1) To determine the effectiveness of tephra particles in the catalysis of the liquid water to ice phase transformation, with application to ice hydrometeor formation in volcanic clouds. (2) To determine the sedimentological characteristics of distal (100s km) tephra fallout from recent volcanic clouds. (3) To assess particle fallout rates from recent volcanic clouds in the context of observed deposit characteristics. (4) To assess the implications of hydrometeor formation on the enhancement of volcanic sedimentation and the potential for cloud destabilization from volcanic hydrometeor sublimation. Dissertation Overview. The following chapters present the analysis, results and conclusions of heterogeneous ice nucleation experiments and sedimentological characterization of several recent tephra deposits. The dissertation is organized in three chapters, each prepared in journal article format. In Chapter 1

  2. Communicating Uncertainty in Volcanic Ash Forecasts: Decision-Making and Information Preferences

    Science.gov (United States)

    Mulder, Kelsey; Black, Alison; Charlton-Perez, Andrew; McCloy, Rachel; Lickiss, Matthew

    2016-04-01

    The Robust Assessment and Communication of Environmental Risk (RACER) consortium, an interdisciplinary research team focusing on communication of uncertainty with respect to natural hazards, hosted a Volcanic Ash Workshop to discuss issues related to volcanic ash forecasting, especially forecast uncertainty. Part of the workshop was a decision game in which participants including forecasters, academics, and members of the Aviation Industry were given hypothetical volcanic ash concentration forecasts and asked whether they would approve a given flight path. The uncertainty information was presented in different formats including hazard maps, line graphs, and percent probabilities. Results from the decision game will be presented with a focus on information preferences, understanding of the forecasts, and whether different formats of the same volcanic ash forecast resulted in different flight decisions. Implications of this research will help the design and presentation of volcanic ash plume decision tools and can also help advise design of other natural hazard information.

  3. Geochemical Characteristics of Danfeng Meta-Volcanic Rocks in Shangzhou Area,Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    The Danfeng meta-volcanics in the Shangzhou area, Shaanxi Province are characterized by oceanic island arc volcanic geochemistry. They are a suite of low-K tholeiitic series and calc-alkaline series meta-volcanic rocks derived from different sources respectively.These meta-volcanics have high Th/Ta ratios and low contents of Ni,Ta,Ti,Y and Yb, suggesting that they were influenced by the subduction zone components.Many lines of evidence show that the Danfeng meta-volcanics were produced in an oceanic island are setting of the supra-subduction zone at the southern margin of the North China Block during the Early Paleozoic.

  4. Climatic impact of volcanic eruptions

    Science.gov (United States)

    Rampino, Michael R.

    1991-01-01

    Studies have attempted to 'isolate' the volcanic signal in noisy temperature data. This assumes that it is possible to isolate a distinct volcanic signal in a record that may have a combination of forcings (ENSO, solar variability, random fluctuations, volcanism) that all interact. The key to discovering the greatest effects of volcanoes on short-term climate may be to concentrate on temperatures in regions where the effects of aerosol clouds may be amplified by perturbed atmospheric circulation patterns. This is especially true in subpolar and midlatitude areas affected by changes in the position of the polar front. Such climatic perturbation can be detected in proxy evidence such as decrease in tree-ring widths and frost rings, changes in the treeline, weather anomalies, severity of sea-ice in polar and subpolar regions, and poor grain yields and crop failures. In low latitudes, sudden temperature drops were correlated with the passage overhead of the volcanic dust cloud (Stothers, 1984). For some eruptions, such as Tambora, 1815, these kinds of proxy and anectdotal information were summarized in great detail in a number of papers and books (e.g., Post, 1978; Stothers, 1984; Stommel and Stommel, 1986; C. R. Harrington, in press). These studies lead to the general conclusion that regional effects on climate, sometimes quite severe, may be the major impact of large historical volcanic aerosol clouds.

  5. Atmospheric chemistry in volcanic plumes.

    Science.gov (United States)

    von Glasow, Roland

    2010-04-13

    Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and heterogeneous reactions on aerosol particles that have previously been unexplored for this type of volcanic plumes. Key features of these measurements can be reproduced by numerical models such as the one employed in this study. The model shows sustained high levels of reactive bromine in the plume, leading to extensive ozone destruction, that, depending on plume dispersal, can be maintained for several days. The very high concentrations of sulfur dioxide in the volcanic plume reduces the lifetime of the OH radical drastically, so that it is virtually absent in the volcanic plume. This would imply an increased lifetime of methane in volcanic plumes, unless reactive chlorine chemistry in the plume is strong enough to offset the lack of OH chemistry. A further effect of bromine chemistry in addition to ozone destruction shown by the model studies presented here, is the oxidation of mercury. This relates to mercury that has been coemitted with bromine from the volcano but also to background atmospheric mercury. The rapid oxidation of mercury implies a drastically reduced atmospheric lifetime of mercury so that the contribution of volcanic mercury to the atmospheric background might be less than previously thought. However, the implications, especially health and environmental effects due to deposition, might be substantial and warrant further studies, especially field measurements to test this hypothesis.

  6. Petrology of peraluminous and peralkaline rhyolites from the SE Lake Chad (northernmost Cameroon Line)

    Science.gov (United States)

    Mbowou, Gbambié Isaac Bertrand; Botelho, Nilson Francisquini; Lagmet, Claudial Amane; Ngounouno, Ismaïla

    2015-12-01

    Peraluminous (P.I. 1) rhyolites from SE Lake Chad consisted of quartz, alkali feldspar and oxides-hydroxides phenocrysts, display negative Eu anomaly. F-arfvedsonite, augite-hedenbergite, aegirine and aegirine-augite are present in peralkaline rhyolites. The peralkaline and peraluminous rhyolitic magmas of the SE Lake Chad derive likely from the same source, according to their coexistence on the same volcano (Hadjer Bigli); their similar Zr/Nb, Zr/Hf ratios and their linear trends established in Zr vs Nb, Zr vs Ta and Zr vs Y diagrams, which linked to removal of successive batches of magma from a mantle source or to different degrees of partial melting. These magmas generated from the partial melting model of the underplated mantle, which would have induced the intrusion of crustal materials, triggering the hydrothermal reactions. Although, the high Zr amounts are not related to bulk assimilation of partially melted crustal materials.

  7. [Primary health care in a prison environment, the Cameroon experience].

    Science.gov (United States)

    Demoures, B; Nkodo-Nkodo, E; Mbam-Mbam, L

    1998-01-01

    People isolated from their families, such as prisoners, are the most vulnerable to the consequences of the economic crisis in Africa. Some non-governmental organizations are taking action to improve health care conditions in prisons. We describe herein such a project, conducted in the town of Ngaoundéré, Adamaoua Province, Cameroon. The prison houses 400 prisoners, mostly men. Catholic missionaries have been involved in improving conditions since 1988, at the request of a magistrate from the local tribunal. They have introduced a community store, handicrafts and the teaching of reading and writing, carried out by the prisoners themselves. The Catholic Health Service was asked to join the project in October 1992. Its participation was part of the provincial policy of collaboration between private and public organizations for the improvement of health institutions. Meetings between health workers and prisoners first created an opportunity for the prisoners to talk about their concerns and what they wanted. A health committee, consisting of about 10 prisoners took several initiatives related to hygiene. Access to curative care was then improved by increasing the stock of medicines to include 37 drugs, standardizing the therapeutic recommendations (including those of the national program against tuberculosis) and increasing the prisoners' access to health care by making the pharmacy self-sufficient. The pharmacy's prices are low and the wardens and their families are encouraged to use it. Any profit made goes towards a "solidarity fund" managed by the prisoners, which enables them to buy their own drugs (3 to 5 patients are seen each day by the nurse). The link between money entering the system and the supply of drugs was studied. Most of the diseases reported between July 1994 and July 1995 were infectious, including scabies infections and acute respiratory infections (mean of 5 cases per month). Fifteen cases of tuberculosis were diagnosed and treated. AIDS was not

  8. The simultaneous loop flow correction analysis in the water feed network of Minkok Edjombo (SOUTH –CAMEROON.

    Directory of Open Access Journals (Sweden)

    MENDOMO MEYE SERGES

    2014-11-01

    Full Text Available With increasing population growth and industrial development, water flow rates and other hydraulic requirements associated with water distribution systems have been estimated to increase both national and local scale. Water shortage will cause inconvenience to people’s life and it will impact city function and industrial production. Hence to overcome this problem design and analysis of water distribution system is necessary to get optimal discharge. In this paper a water pipeline network analysis with a case study of a small city (MinkokEdjombo in the southern Cameroon system has been undertaken. What prompted this study is that the case study has a lot of fluctuations in its head loss. Also, the discharge is not proportional to the pipe diameter. The study therefore adopted simultaneous loop flow correction method because it computes simultaneous flows corrections for all loops, hence, the best since computational procedures takes into account the iterative influence of flow corrections between loops which have common pipes. After applying the simultaneous loop flow correction analyze in a twenty-four sampled pipeline network, a drastic reduction in head loss and regular line along the axis was observed. Besides, the rate at which the water flows was observed to be proportional to the pipe diameter. Hence, the method is a useful aid in planning, designing and operating of reticulated pipeline network for higher efficiency and improved economy.

  9. Effects of human presence on chimpanzee nest location in the Lebialem-Mone forest landscape, Southwest Region, Cameroon.

    Science.gov (United States)

    Last, Cadell; Muh, Bernice

    2013-01-01

    In several areas of Africa, great apes experience increasing predation pressure as a result of human activities. In this study, terrestrial and arboreal nest construction among chimpanzee (Pan troglodytes ellioti) populations was investigated in the Lebialem-Mone Forest Landscape (LMFL), Southwest Region, Cameroon, to examine the anthropogenic effects on nest location. Data on the height, distribution and approximate age of chimpanzee night nests were collected during two 4-week primate field surveys (July to August 2010; July 2011) at two field sites (Bechati and Andu) within the LMFL. Data were collected using the line transect method. Chimpanzee night nests were categorized by their location: arboreal versus terrestrial. During the two field surveys, arboreal night nests were the most frequently constructed nest type at both sites, and the only type of night nest constructed at Bechati. Terrestrial night nests were also constructed at Andu. The main difference between these two sites is the level of human predation and agricultural development. At Bechati chimpanzees inhabit forest regions around dense, expanding villages and are regularly hunted by humans. However, at Andu the chimpanzee populations are not under the same threat. Therefore, terrestrial night nest construction in the LMFL appears to be a behavior exhibited where there is less human presence. PMID:23406888

  10. Geopulsation, Volcanism and Astronomical Periods

    Institute of Scientific and Technical Information of China (English)

    Yang Xuexiang; Chen Dianyou; Yang Xiaoying; Yang Shuchen

    2000-01-01

    Volcanism is mainly controlled by the intermittent release of energy in the earth. As far as the differential rotation of the earth's inner core is concerned, the Galactic Year may change the gravitational constant G, the solar radiative quantity and the moving speed of the solar system and affect the exchange of angular momentum between core and mantle as well as the energy exchange between crust and mantle. As a result, this leads to eruptions of superplumes and magma, and controls the energy flow from core - mantle boundary (CMB) to crust. When the earth' s speed decreases, it will release a huge amount of energy. They are the reason of the correspondence of the volcanic cycles one by one with the astronomical periods one by one. According to the astronomical periods, volcanic eruptions may possibly be predicted in the future.

  11. Geochemical study for volcanic surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Panichi, C.; La Ruffa, G. [Consiglio Nazionale delle Ricerche, International Institute for Geothermal Research Ghezzano, PI (Italy)

    2000-07-01

    For years, geologists have been striving to reconstruct volcanic eruptions from the analysis of pyroclastic deposits and lava flows on the surface of the earth and in the oceans. This effort has produced valuable information on volcanic petrology and magma generation, separation, mixing, crystallisation, and interaction with water in phreatomagmatic and submarine eruptions. The volcanological process are tied to the dynamics of the earth's crust and lithosphere. The mantle, subducted oceanic crust, and continental crust contain different rock types and are sources of different magmas. Magmas consist primarily of completely or partially molten silicates containing volatile materials either dissolved in the melt or as bubbles of gas. The silicate and volatile portions affect the physical properties of magma and, therefore, the nature of a volcanic eruption.

  12. L'imaginaire du volcan

    OpenAIRE

    Bertrand, Dominique; Bosquet, Marie-Françoise; Bozzetto, Roger; Chamart, Gabrielle; Chelebourg, Christian; Chenet-Faugeras, Françoise; Collot, Michel; Cornille, Jean-Louis; Gaillard, Aurélia; Lavocat, Françoise; Frank LESTRINGANT; Racault, Jean-Michel; SHINODA, Chiwaki; Sylvos, Françoise; Tardieu, Jean-Pierre

    2016-01-01

    Quelle force naturelle pouvait, mieux que le volcan, devenir la métaphore vive de l'enthousiasme poétique ? Auteur du paysage qu'il remodèle après l'avoir détruit, sculpteur de laves autant qu'objet pittoresque, le volcan est dans la littérature un actant essentiel, un relais de l'auteur, comme le montre ce voyage dans la mémoire des représentations volcaniques.

  13. Sismos y volcanes en Colombia

    OpenAIRE

    Duque Escobar, Gonzalo

    2010-01-01

    Notas sobre las zonas de amenaza sísmica y principales fuentes sísmicas de Colombia, y los segmentos volcánicos de los Andes colombianos con los principales volcanes activos, de conformidad con los estudios del Ingeominas. Anexos a títulos con sus correspondientes enlaces, para ofrecer artículos relacionados con sismos y volcanes, en los que se consideran aspectos de interés para la gestión del riesgo sísmico y volcánico en Colombia

  14. Recurrence models of volcanic events: Applications to volcanic risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M. [Los Alamos National Lab., Las Vegas, NV (United States); Picard, R.; Valentine, G. [Los Alamos National Lab., NM (United States); Perry, F.V. [New Mexico Univ., Albuquerque, NM (United States)

    1992-03-01

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Risk used in this context refers to a combined assessment of the probability and consequences of future volcanic activity. Past studies established bounds on the probability of magmatic disruption of a repository. These bounds were revised as additional data were gathered from site characterization studies. The probability of direct intersection of a potential repository located in an eight km{sup 2} area of Yucca Mountain by ascending basalt magma was bounded by the range of 10{sup {minus}8} to 10{sup {minus}10} yr{sup {minus}1 2}. The consequences of magmatic disruption of a repository were estimated in previous studies to be limited. The exact releases from such an event are dependent on the strike of an intruding basalt dike relative to the repository geometry, the timing of the basaltic event relative to the age of the radioactive waste and the mechanisms of release and dispersal of the waste radionuclides in the accessible environment. The combined low probability of repository disruption and the limited releases associated with this event established the basis for the judgement that the risk of future volcanism was relatively low. It was reasoned that that risk of future volcanism was not likely to result in disqualification of the potential Yucca Mountain site.

  15. Recurrence models of volcanic events: Applications to volcanic risk assessment

    International Nuclear Information System (INIS)

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Risk used in this context refers to a combined assessment of the probability and consequences of future volcanic activity. Past studies established bounds on the probability of magmatic disruption of a repository. These bounds were revised as additional data were gathered from site characterization studies. The probability of direct intersection of a potential repository located in an eight km2 area of Yucca Mountain by ascending basalt magma was bounded by the range of 10-8 to 10-10 yr-12. The consequences of magmatic disruption of a repository were estimated in previous studies to be limited. The exact releases from such an event are dependent on the strike of an intruding basalt dike relative to the repository geometry, the timing of the basaltic event relative to the age of the radioactive waste and the mechanisms of release and dispersal of the waste radionuclides in the accessible environment. The combined low probability of repository disruption and the limited releases associated with this event established the basis for the judgement that the risk of future volcanism was relatively low. It was reasoned that that risk of future volcanism was not likely to result in disqualification of the potential Yucca Mountain site

  16. A quantitative model for volcanic hazard assessment

    OpenAIRE

    Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Sandri, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Furlan, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia

    2006-01-01

    Volcanic hazard assessment is a basic ingredient for risk-based decision-making in land-use planning and emergency management. Volcanic hazard is defined as the probability of any particular area being affected by a destructive volcanic event within a given period of time (Fournier d’Albe 1979). The probabilistic nature of such an important issue derives from the fact that volcanic activity is a complex process, characterized by several and usually unknown degrees o...

  17. Volcanic ash - Terrestrial versus extraterrestrial

    Science.gov (United States)

    Okeefe, J. A.

    1976-01-01

    A principal difference between terrestrial and extraterrestrial lavas may consist in the greater ability of terrestrial lavas to form thin films (like those of soap bubbles) and hence foams. It would follow that, in place of the pumice and spiny shards found in terrestrial volcanic ash, an extraterrestrial ash should contain minute spherules. This hypothesis may help to explain lunar microspherules.

  18. Lung problems and volcanic smog

    Science.gov (United States)

    ... www.ncbi.nlm.nih.gov/pubmed/17650330 . Volcanic Air Pollution -- A Hazard in Hawai'i. U.S. Geological Survey. Last updated October 2004. U.S. Geological Survey Fact Sheet 169-197. Accessed April 22, 2012. Available at: ...

  19. Infrasound research of volcanic eruptions

    Science.gov (United States)

    Marchetti, Emanuele; Ripepe, Maurizio

    2016-04-01

    Volcanic eruptions are efficient sources of infrasound produced by the rapid perturbation of the atmosphere by the explosive source. Being able to propagate up to large distances from the source, infrasonic waves from major (VEI 4 or larger) volcanic eruptions have been recorded for many decades with analogue micro-barometers at large regional distances. In late 1980s, near-field observations became progressively more common and started to have direct impact on the understanding and modeling of explosive source dynamics, to eventually play a primary role in volcano research. Nowadays, infrasound observation from a large variety of volcanic eruptions, spanning from VEI 0 to VEI 5 events, has shown a dramatic variability in terms of signature, excess pressure and frequency content of radiated infrasound and has been used to infer complex eruptive source mechanisms for the different kinds of events. Improved processing capability and sensors has allowed unprecedented precise locations of the explosive source and is progressively increasing the possibility to monitor volcanoes from distant records. Very broadband infrasound observations is also showing the relation between volcanic eruptions and the atmosphere, with the eruptive mass injection in the atmosphere triggering acoustic-gravity waves which eventually might control the ash dispersal and fallout.

  20. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    Three basic topics are addressed for the disruptive event analysis: first, the range of disruptive consequences of a radioactive waste repository by volcanic activity; second, the possible reduction of the risk of disruption by volcanic activity through selective siting of a repository; and third, the quantification of the probability of repository disruption by volcanic activity

  1. Reducing Emissions from Deforestation and Degradation in Cameroon. Assessing costs and benefits

    International Nuclear Information System (INIS)

    A new momentum is underway to account for emissions from 'avoided deforestation and degradation' at the United Nations Framework Convention on Climate Change (UNFCCC). This paper assesses the feasibility of one of the Reducing Emissions from Deforestation and Degradation (REDD) mechanisms currently discussed, namely that of 'Compensated Reduction', in the case of Cameroon. Here we assess the differential revenues that a farmer could get from 1 ha of land out of two alternative land-uses: shifting cultivation, the traditional land-use pattern in southern Cameroon, or carbon credits as compensation for the conservation of primary forest. It is found that a break-even price of USD 2.85/t of carbon dioxide equivalent would level shifting cultivation with 'Compensated Reduction'. This result suggests that at current carbon prices, and independently form variations in the discount rate, it could already be more profitable to preserve the primary forest rather than to log it in order to grow crops. (author)

  2. Survey of Minerai Status of Cattle in the Adamaoua Region of Cameroon

    Directory of Open Access Journals (Sweden)

    Njwe, RM.

    1994-01-01

    Full Text Available Serum and liver samples were collected from Zebu Gudali and Zebu Banyo cattle freshly slaughtered in abattoirs at eight different locations in each of the five administrative divisions of the Adamaoua region of Cameroon during the wet season (September to October, 1983 and the dry season (February to March, 1984. Liver samples were analysed for iron, copper and manganese while serum samples were analysed for calcium, magnesium and copper. Most of the animals were adequate in calcium, magnesium, iron and manganese. Copper was deficient in liver and sera of most of the animals. There is a need to intensif/research on the mineral status of cattle in the Adamaoua region of Cameroon. Copper sulphate is recommended in sait licks for cattle in this region.

  3. The urgent need for environmental sanitation and a safe drinking water supply in Mbandjock, Cameroon.

    Science.gov (United States)

    Tchounwou, P B; Lantum, D M; Monkiedje, A; Takougang, I; Barbazan, P

    1997-07-01

    Studies were conducted to assess the physical, chemical, and bacteriological qualities of drinking water in Mbandjock, Cameroon. Study results indicated that the vast majority of drinking water sources possessed acceptable physical and chemical qualities, according to the World Health Organization standards. However, microbiological analyses revealed that only the waters treated by the Cameroon National Water Company (SNEC) and the Sugar Processing Company (SOSUCAM) were acceptable for human consumption. All spring and well waters presented evidences of fecal contamination from human and/or animal origin. Water from these sources should, therefore, be treated before use for drinking. Since the majority of the population gets its water from wells and springs, there is an urgent need to develop a health education program, within the framework of primary health care, with respect to environmental sanitation and safe drinking water supply in this community. PMID:9216865

  4. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo.

    Science.gov (United States)

    Papachroni, Danai; Graikou, Konstantia; Kosalec, Ivan; Damianakos, Harilaos; Ingram, Verina; Chinou, Ioanna

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their structures were elucidated on the basis of spectral evidence. Three triterpenes and two diprenyl-flavonoids were identified from Congo propolis, which has been investigated for the first time, while thirteen triterpenes, three diprenyl-flavonoids, two monoterpenic alcohols and one fatty acid ester have been identified from Cameroon propolis samples. To our knowledge, the identified diprenyl-flavonoids, as well as five of the isolated and determined triterpenes, are reported for the first time in propolis. Moreover, the total polyphenol content was estimated in all extracts and the antimicrobial activities of all four extracts were studied against six Gram-positive and -negative bacteria and three pathogenic fungi, showing an interesting antibacterial profile.

  5. Marine pollution in Cameroon (Gulf of Guinea): State and remedies for successful control and monitoring

    International Nuclear Information System (INIS)

    This paper analyses the various research results obtained over several years in Cameroon on coastal and marine pollution, especially pollution by solid wastes, industrial and domestic effluents, hydrocarbons (tar balls), heavy metals and pesticides. Values in the order of 175,531 and 194,685 tons have been estimated for annual pollution loads in terms of BOD and suspended matter respectively. With respect to BOD, the most polluting industries are petroleum refineries, food processing and chemical industries which respectively represent 38, 36 and 10% of the total annual BOD. Measurement of tar balls on various Cameroonian beaches shows values as high as 42.40 g/m2 of beach, while the concentration of heavy metals encountered in shrimps and fish consumed in Cameroon shows a very wide range of values. Most of these values are similar to those obtained within the region, and some are alarming in their magnitude

  6. Health impact assessment and evaluation of a clinical waste management policy for Cameroon

    Directory of Open Access Journals (Sweden)

    Gabriel Gulis

    2013-09-01

    Full Text Available Health impact assessment (HIA was carried out to evaluate development of a clinical waste management policy for Cameroon. Fifteen stakeholders of different portfolios within the health sector were selected during a HIA initiating study trip to the Northwest region of Cameroon. Questionnaires were then developed and emailed to the stakeholders. The stakeholders identified cross-contamination, environmental pollution, physical injuries and poor waste management sites as potential risk factors that can be associated with poor clinical waste management. They recommended strong economic and political capital as a prerequisite for the development and implementation of a successful clinical waste policy. Local impacts on health, according to the stakeholders, should be prioritized in deciding any treatment and disposal option. The whole HIA process run through 2008-2010.

  7. Experimental generation of volcanic lightning

    Science.gov (United States)

    Cimarelli, Corrado; Alatorre-Ibargüengoitia, Miguel; Kueppers, Ulrich; Scheu, Bettina; Dingwell, Donald B.

    2014-05-01

    Ash-rich volcanic plumes that are responsible for injecting large quantities of aerosols into the atmosphere are often associated with intense electrical activity. Direct measurement of the electric potential at the crater, where the electric activity in the volcanic plume is first observed, is severely impeded, limiting progress in its investigation. We have achieved volcanic lightning in the laboratory during rapid decompression experiments of gas-particle mixtures under controlled conditions. Upon decompression (from ~100 bar argon pressure to atmospheric pressure), loose particles are vertically accelerated and ejected through a nozzle of 2.8 cm diameter into a large tank filled with air at atmospheric conditions. Because of their impulsive character, our experiments most closely represent the conditions encountered in the gas-thrust region of the plume, when ash is first ejected from the crater. We used sieved natural ash with different grain sizes from Popocatépetl (Mexico), Eyjafjallajökull (Iceland), and Soufrière Hills (Montserrat) volcanoes, as well as micrometric glass beads to constrain the influence of material properties on lightning. We monitored the dynamics of the particle-laden jets with a high-speed camera and the pressure and electric potential at the nozzle using a pressure transducer and two copper ring antennas connected to a high-impedance data acquisition system, respectively. We find that lightning is controlled by the dynamics of the particle-laden jet and by the abundance of fine particles. Two main conditions are required to generate lightning: 1) self-electrification of the particles and 2) clustering of the particles driven by the jet fluid dynamics. The relative movement of clusters of charged particles within the plume generates the gradient in electrical potential, which is necessary for lightning. In this manner it is the gas-particle dynamics together with the evolving particle-density distribution within different regions of

  8. Amodiaquine-Artesunate versus Artemether-Lumefantrine against Uncomplicated Malaria in Children Less Than 14 Years in Ngaoundere, North Cameroon: Efficacy, Safety, and Baseline Drug Resistant Mutations in pfcrt, pfmdr1, and pfdhfr Genes.

    Science.gov (United States)

    Ali, Innocent M; Netongo, Palmer M; Atogho-Tiedeu, Barbara; Ngongang, Eric-Olivier; Ajua, Anthony; Achidi, Eric A; Mbacham, Wilfred F

    2013-01-01

    Background. In Cameroon, both Artesunate-amodiaquine (AS/AQ) and artemether-lumefantrine (AL) are used as first-line treatment against uncomplicated malaria in line with the WHO recommendations. We compared the efficacy and safety of both therapeutic combinations and determined the prevalence of drug resistance conferring mutations in three parasite genes. Methods. One hundred and fifty acute malaria patients between six months and 14 years of age were randomized to receive standard doses of either AS/AQ (73) or AL (77) and followedup for 28 days. Outcome of treatment was according to the standard WHO classification. DNA samples from pretreatment parasite isolates were used to determine the prevalence of resistant mutations in the pfcrt, pfmdr1, and dhfr genes. Results. Both drug combinations induced rapid clearance of parasites and malaria symptoms. PCR-corrected cure rates were 100% and 96.4% for AL. The combinations were well tolerated. Major haplotypes included CVIET (71%), CVMNT (25%) for the pfcrt; SND (100%) for the pfmdr1; IRN (79, 8%), NCS (8.8%), and mixed haplotype (11, 8%) for the dhfr. Conclusion. Both AS/AQ and AL were highly effective and well tolerated for the treatment of uncomplicated falciparum malaria in Ngaoundere, Cameroon. High prevalence of mutant pfcrt alleles confirms earlier observations. Long-term monitoring of safety and efficacy and molecular markers is highly solicited.

  9. Amodiaquine-Artesunate versus Artemether-Lumefantrine against Uncomplicated Malaria in Children Less Than 14 Years in Ngaoundere, North Cameroon: Efficacy, Safety, and Baseline Drug Resistant Mutations in pfcrt, pfmdr1, and pfdhfr Genes

    Directory of Open Access Journals (Sweden)

    Innocent M. Ali

    2013-01-01

    Full Text Available Background. In Cameroon, both Artesunate-amodiaquine (AS/AQ and artemether-lumefantrine (AL are used as first-line treatment against uncomplicated malaria in line with the WHO recommendations. We compared the efficacy and safety of both therapeutic combinations and determined the prevalence of drug resistance conferring mutations in three parasite genes. Methods. One hundred and fifty acute malaria patients between six months and 14 years of age were randomized to receive standard doses of either AS/AQ (73 or AL (77 and followedup for 28 days. Outcome of treatment was according to the standard WHO classification. DNA samples from pretreatment parasite isolates were used to determine the prevalence of resistant mutations in the pfcrt, pfmdr1, and dhfr genes. Results. Both drug combinations induced rapid clearance of parasites and malaria symptoms. PCR-corrected cure rates were 100% and 96.4% for AL. The combinations were well tolerated. Major haplotypes included CVIET (71%, CVMNT (25% for the pfcrt; SND (100% for the pfmdr1; IRN (79, 8%, NCS (8.8%, and mixed haplotype (11, 8% for the dhfr. Conclusion. Both AS/AQ and AL were highly effective and well tolerated for the treatment of uncomplicated falciparum malaria in Ngaoundere, Cameroon. High prevalence of mutant pfcrt alleles confirms earlier observations. Long-term monitoring of safety and efficacy and molecular markers is highly solicited.

  10. Conceptions of literacy in context:situated understandings in a rural area of Northern Cameroon

    OpenAIRE

    Cheffy, Ian

    2008-01-01

    Taking a view of literacy as a communicative practice, in which a learned skill is applied by individual people in their particular social contexts, this thesis examines the understandings of literacy of people in a village in northern Cameroon and explores how these are influenced by the circumstances of their lives. Many developments have taken place in local life in the last fifty years as the village has become progressively integrated into a wider world. Most people are small farmers; po...

  11. Contribution of Augosoma centaurus beetle to rural livelihoods in the East region of Cameroon : study report

    OpenAIRE

    F. J. Muafor; Le Gall, Philippe; Levang, Patrice

    2012-01-01

    This report describes the level to which forest dependent people in the East region of Cameroon rely on the consumption of Augosoma centaurus beetle (Dynastidae) for food security and rural livelihood. In total, 14 villages and 2 small towns, comprising of 9 ethnic groups in 10 sub-divisions were surveyed using quantitative and qualitative socioeconomic approaches. From the results of this study, both the larvae and adult individuals of the Augosoma beetle are traditional delic...

  12. Antecedents of Service Recovery Performance in 3 and 4 Star Hotels in Douala, Cameroon

    OpenAIRE

    Doh, Winifred Lema

    2013-01-01

    ABSTRACT: In addition to the external environment challenges, the aspect of unjust practices in hiring, promotion and rewarding at the organizational level has recently received a great deal of attention for influencing the performance of frontline employees in service recovery (Yavas et al., 2003) by causing dissatisfaction (Babakus et al., 2003) and reducing their level of affective commitment. The tourism industry in Cameroon and in the Sub-Sahara Africa is infested by all sort external ch...

  13. Awareness, attitudes and prevention of malaria in the cities of Douala and Yaoundé (Cameroon)

    OpenAIRE

    Menze-Djantio Benjamin; Ndo Cyrille; Antonio-Nkondjio Christophe

    2011-01-01

    Abstract Background There is little information on the social perception of malaria and the use of prevention methods in Cameroon. This study was designed to assess knowledge, attitude and management of malaria in households living in the cities of Douala and Yaoundé. Results Over 82% of people interviewed associated malaria transmission to mosquito bites. Methods used for malaria prevention were: environmental sanitation 1645 (76.1%), use of bed nets 1491 (69%), insecticide spray/coils 265 (...

  14. Genetic structure of the tiger mosquito, Aedes albopictus, in Cameroon (Central Africa.

    Directory of Open Access Journals (Sweden)

    Basile Kamgang

    Full Text Available BACKGROUND: Aedes albopictus (Skuse, 1884 (Diptera: Culicidae, a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa, thereby deducing their likely geographic origin. METHODS AND RESULTS: Mosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI. All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (F(ST  = 0.068, P < 0.0001. Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups. CONCLUSION: The moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions.

  15. Genetic Structure of the Tiger Mosquito, Aedes albopictus, in Cameroon (Central Africa)

    Science.gov (United States)

    Kamgang, Basile; Brengues, Cécile; Fontenille, Didier; Njiokou, Flobert; Simard, Frédéric; Paupy, Christophe

    2011-01-01

    Background Aedes albopictus (Skuse, 1884) (Diptera: Culicidae), a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa), thereby deducing their likely geographic origin. Methods and Results Mosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI). All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (FST = 0.068, P<0.0001). Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups. Conclusion The moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions. PMID:21629655

  16. Higher insertion in marketing and vulnerability of cattle farms in North Cameroon

    OpenAIRE

    Djamen, Patrice; Lossouarn, Jean; Havard, Michel; Hassana,; Bouba, Raymond; Tiékwa, Cathy

    2008-01-01

    Does higher commercial insertion constitutes for livestock keepers an opportunity in fostering the transformation of their farms, or a risk likely to further weaken their farms? This issue is arising in Northern Cameroon where traditional livestock farming systems are hampered by high pressure on land while high population growth and rapid urbanization stimulate the development of dairy products and beef markets. A research was carried out to identify the effects of commercial insertion on th...

  17. Sustainable community-based management and conservation of mangrove ecosystems in Cameroon.

    OpenAIRE

    2011-01-01

    Mangrove ecosystems on the coast of Cameroon are valuable both for their contributions to local livelihoods and the globally important biodiversity that they contain. However, these areas are threatened by a number of development pressures as well as unsustainable management and harvesting practices of the local communities living there. This project aims to strengthen protection and reduce degradation in these areas by supporting inter-sectoral co-ordination and collaboration (within an a...

  18. Habitat and diversity of ectomycorrhizal fungi in forests of South Cameroon

    OpenAIRE

    Onguene, N.A.; Kuyper, T. W.

    2012-01-01

    Information is lacking on habitat and diversity of ectomycorrhizal (ECM) fungi of African humid forests. For three years, mushroom excursions were carried out in four sites with contrasted soil and altitude characteristics of South Cameroon, during wet seasons. Collected fungi were described in fresh state and dried exsiccates examined for microscopic description before morpho-anatomical identification. ECM fungi abundantly fruited exclusively in mixed caesalp, monodominant Gilbertiodendron a...

  19. Cameroon: UN group finds detention of gay men a violation of human rights.

    Science.gov (United States)

    Pearshouse, Richard; Klein, Alana

    2006-12-01

    In an opinion issued on 11 October 2006, the United Nations Working Group on Arbitrary Detention declared that the detention of 11 men in Cameroon on the basis of their presumed sexual orientation constituted an arbitrary deprivation of liberty and a violation of the principle of equal protection of the law. The Working Group called on the Cameroonian government to "examine the possibility of amending the legislation" criminalizing homosexual sex. PMID:17373068

  20. Vulnerability to Climate Change of Mangroves: Assessment from Cameroon, Central Africa

    OpenAIRE

    Isabella Zouh; Joanna C Ellison

    2012-01-01

    Intertidal mangrove ecosystems are sensitive to climate change impacts, particularly to associated relative sea level rise. Human stressors and low tidal range add to vulnerability, both characteristics of the Doula Estuary, Cameroon. To investigate vulnerability, spatial techniques were combined with ground surveys to map distributions of mangrove zones, and compare with historical spatial records to quantify change over the last few decades. Low technology techniques were used to establish ...

  1. A data support infrastructure for Clean Development Mechanism forestry implementation: an inventory perspective from Cameroon

    OpenAIRE

    Minang, Peter A.; McCall, Michael K.; Skutsch, Margaret M.; Verplanke, Jeroen J.

    2007-01-01

    Clean Development Mechanism (CDM) forestry project development requires highly multi-disciplinary and multiple-source information that can be complex, cumbersome and costly to acquire. Yet developing countries in which CDM projects are created and implemented are often data poor environments and unable to meet such complex information requirements. Using Cameroon as an example, the present paper explores the structure of an enabling host country data support infrastructure for CDM forestry im...

  2. The Burden of Leprosy in Cameroon: Fifteen Years into the Post-elimination Era

    Science.gov (United States)

    Tabah, Earnest Njih; Nsagha, Dickson Shey; Bissek, Anne-Cecile Zoung-Kanyi; Bratschi, Martin W.; Njamnshi, Theophilus Ngeh; Plushke, Gerd; Njamnshi, Alfred Kongnyu

    2016-01-01

    Background Cameroon achieved the elimination target of leprosy in 2000, and has maintained this status ever since. However, a number of health districts in the country continue to report significant numbers of leprosy cases. The aim of this study was to assess the burden of leprosy in Cameroon from 2000 to 2014. Methods We obtained and analysed using the new leprosy burden concept of analysis, leprosy surveillance data collected between 2000 and 2014 from the National Leprosy Control Programme. Principal findings Cameroon achieved leprosy elimination in 2000, registering a prevalence rate of 0.94/10,000 population. The prevalence rate dropped further to reach 0.20/10,000 population (78% reduction) in 2014. Similarly, the new case detection rate dropped from 4.88/100,000 population in 2000 to 1.46/100,000 population (85.3% reduction) in 2014. All 10 regions of the country achieved leprosy elimination between 2000 and 2014; however, 10 health districts were still to do so by 2014. The number of high-leprosy-burden regions decreased from 8 in 2000 to 1 in 2014. Seven and two regions were respectively medium and low-burdened at the end of 2014. At the health districts level, 18 remained at the high-leprosy-burdened level in 2014. Conclusion The leprosy prevalence and detection rates as well as the overall leprosy burden in Cameroon have dropped significantly between 2000 and 2014. However, a good number of health districts remain high-leprosy-burdened. The National Leprosy Control Programme should focus efforts on these health districts in the next coming years in order to further reduce the burden of leprosy in the country. PMID:27732603

  3. The management of wild yam tubers by the Baka pygmies in Southern Cameroon

    OpenAIRE

    Dounias, Edmond

    2001-01-01

    Wild yams (#Dioscorea$ spp.) are primordial sources of carbohydrates for many hunter-gatherers of African forests. Yams play a key role in the symbolic perception of the forest by the Baka Pygmies of Southern Cameroon. The Baka have elaborated an original form of wild yam exploitation that I have termed "paracultivation". Paracultivation defines a set of technical, social and cultural practices aiming at managing wild resources while keeping them in their natural environment. In 1994, I under...

  4. NUCLEAR DNA CONTENT ANALYSIS OF FOUR CULTIVATED SPECIES OF YAMS (DIOSCOREA SPP.) FROM CAMEROON

    OpenAIRE

    Marie F. Sandrine; Simon Joly; Mickaël Bourge; Spencer Brown; Denis N. Omokolo

    2014-01-01

    Yam (Dioscorea spp.) is an important food source in Africa, but diseases and storage pests hinder the African farmers to achieve high yields during the harvest. One important limitation to the genetic breeding of yam is the relatively unknown ploidy level variation within and among species.  The objective of this study was to determine the nuclear DNA content of 59 accessions representing four cultivated Dioscorea species collected from three regions of Cameroon (Adamawa, Centre and Southwest...

  5. Survey of water bugs in bankim, a new buruli ulcer endemic area in cameroon.

    OpenAIRE

    Jean-François Guégan; Philippe Legall; Jordi Landier; Laurent Marsollier; Estelle Marion; Sara Eyangoh; Solange Meyin A Ebong

    2012-01-01

    Buruli ulcer is a debitliating human skin disease with an unknown transmission mode although epidemiological data link it with swampy areas. Data available suggest that aquatic insects play a role in the dissemination and/or transmission of this disease. However, their biodiversity and biology remain poorly documented. We conducted an entomological survey in Bankim, Cameroon, an area recently described as endemic for Buruli ulcer in order to identify the commonly occurring aquatic bugs and do...

  6. Traditional Knowledge on Medicinal Plants Use by Ethnic Communities in Douala, Cameroon

    OpenAIRE

    Emmanuel Mpondo Mpondo; Didier Dibong Siegfried

    2012-01-01

    Traditional knowledge is common and important among the tribal people but much of the information is empirical at best lacking logical validation. A number of ethnic communities residing in the study area are partially or fully dependent on the forest resources to meet their requirements. Plants have traditionally been used as a source of medicine in Cameroon since early times for the control of various ailments afflicting humans and their domestic animals. However, little work...

  7. Developing effective chronic disease interventions in Africa: insights from Ghana and Cameroon

    Directory of Open Access Journals (Sweden)

    Boynton Petra

    2010-04-01

    Full Text Available Abstract Background Africa faces an urgent but 'neglected epidemic' of chronic disease. In some countries stroke, hypertension, diabetes and cancers cause a greater number of adult medical admissions and deaths compared to communicable diseases such as HIV/AIDS or tuberculosis. Experts propose a three-pronged solution consisting of epidemiological surveillance, primary prevention and secondary prevention. In addition, interventions must be implemented through 'multifaceted multi-institutional' strategies that make efficient use of limited economic and human resources. Epidemiological surveillance has been prioritised over primary and secondary prevention. We discuss the challenge of developing effective primary and secondary prevention to tackle Africa's chronic disease epidemic through in-depth case studies of Ghanaian and Cameroonian responses. Methods A review of chronic disease research, interventions and policy in Ghana and Cameroon instructed by an applied psychology conceptual framework. Data included published research and grey literature, health policy initiatives and reports, and available information on lay community responses to chronic diseases. Results There are fundamental differences between Ghana and Cameroon in terms of 'multi-institutional and multi-faceted responses' to chronic diseases. Ghana does not have a chronic disease policy but has a national health insurance policy that covers drug treatment of some chronic diseases, a culture of patient advocacy for a broad range of chronic conditions and mass media involvement in chronic disease education. Cameroon has a policy on diabetes and hypertension, has established diabetes clinics across the country and provided training to health workers to improve treatment and education, but lacks community and media engagement. In both countries churches provide public education on major chronic diseases. Neither country has conducted systematic evaluation of the impact of

  8. Conservation concern for the deteriorating geographical range of the Grey Parrot in Cameroon

    OpenAIRE

    Simon A. Tamungang; Cheke, Robert A.; Mofor, Gilbert Z.; Tamungang, Richard N.; Fritz T. Oben

    2014-01-01

    The need for information on Grey Parrot distribution and vegetation associations for informed management and policy decisions was the basis for this study. A nationwide survey of the Grey Parrot population and habitat status was carried out, using questionnaire and point count methods. From the results, the extent of the contemporary range of the parrots was restricted to Southern Cameroon, which harbours the rainforest. Regional parrot population means ranged from 3,487 parrots in the Litto...

  9. Conditions for the sustainable development of the smallholder oil palm sector in Cameroon

    OpenAIRE

    Nkongho, Raymond

    2015-01-01

    The collapse of the FONADER sponsored partnership between oil palm smallholders and major agro-industries in Cameroon together with the structural adjustment program, the devaluation of the Franc CFA, the economic crises, as well as the fall in the international market price for cocoa and coffee, led to the emergence of independent oil palm producers in the country. These oil palm planters have been grappling with the management of their plantation and the processing of their FFB with the use...

  10. Environmental implications of slope deposits in humid tropical africa : evidence from southern cameroon and western kenya

    OpenAIRE

    Kadomura, Hiroshi; Hori, Nobuyuki

    1990-01-01

    Radiocarbon-dated stratigraphic sequence of slope deposits in the humid, now and formerly forested areas of Southern Cameroon and similar stratigraphy in Western Kenya suggest following environmental history: 1) widespread savannization or steppization of closed forests during the Last Glacial Maximum arid phase in the low latitudes; 2) return of humid climates followed by forest reestablishment in the early to middle Holocene (>8,500-3,000 yr B.P.), and 3) anthropogenic transformation of upp...

  11. Wild fauna as a probable animal reservoir for Trypanosoma brucei gambiense in Cameroon

    OpenAIRE

    Njiokou, F.; Laveissière, Claude; Simo, G.; Nkinin, S.; Grébaut, Pascal; Cuny, Gérard; Herder, Stéphane

    2006-01-01

    In order to Study the existence of a wild animal reservoir for Trypanosoma brucei gambiense in South Cameroon, blood was collected from wild animals in three human African trypanosomiasis foci and from a nonendemic control area. The 1142 wild animals sampled belonged to 36 different species pertaining to eight orders (407 primates, 347 artiodactyls, 265 rodents, 54 pangolins, 53 carnivores, 11 Saurians and crocodilians, and five hyraxes). QBC (R) and KIVI tests detected trypanosomes on 1.7% (...

  12. Governance of disaster risk reduction in Cameroon: The need to empower local government

    Directory of Open Access Journals (Sweden)

    Henry N. Bang

    2013-01-01

    Full Text Available The impact of natural hazards and/or disasters in Cameroon continues to hit local communities hardest, but local government lacks the ability to manage disaster risks adequately. This is partly due to the fact that the necessity to mainstream disaster risk reduction into local governance and development practices is not yet an underlying principle of Cameroon’s disaster management framework. Using empirical and secondary data, this paper analyses the governance of disaster risks in Cameroon with particular focus on the challenges local government faces in implementing disaster risk reduction strategies. The hypothesis is that the governance of disaster risks is too centralised at the national level, with huge implications for the effective governance of disaster risks at the local level. Although Cameroon has reinvigorated efforts to address growing disaster risks in a proactive way, it is argued that the practical actions are more reactive than proactive in nature. The overall aim is to explore the challenges and opportunities that local government has in the governance of disaster risks. Based on the findings from this research, policy recommendations are suggested on ways to mainstream disaster risk reduction strategies into local governance, and advance understanding and practice in the local governance of disaster risks in the country.

  13. Nutritional composition, bioactive compounds and volatile profile of cocoa beans from different regions of Cameroon.

    Science.gov (United States)

    Caprioli, Giovanni; Fiorini, Dennis; Maggi, Filippo; Nicoletti, Marcello; Ricciutelli, Massimo; Toniolo, Chiara; Prosper, Biapa; Vittori, Sauro; Sagratini, Gianni

    2016-06-01

    Analysis of the complex composition of cocoa beans provides fundamental information for evaluating the quality and nutritional aspects of cocoa-based food products, nutraceuticals and supplements. Cameroon, the world's fourth largest producer of cocoa, has been defined as "Africa in miniature" because of the variety it habitats. In order to evaluate the nutritional characteristics of cocoa beans from five different regions of Cameroon, we studied their polyphenolic content, volatile compounds and fatty acids composition. The High Performance Thin Layer Chromatography (HPTLC) analysis showed that the Mbalmayo sample had the highest content of theobromine (11.6 mg/g) and caffeic acid (2.1 mg/g), while the Sanchou sample had the highest level of (-)-epicatechin (142.9 mg/g). Concerning fatty acids, the lowest level of stearic acid was found in the Mbalmayo sample while the Bertoua sample showed the highest content of oleic acid. Thus, we confirmed that geographical origin influences the quality and nutritional characteristics of cocoa from these regions of Cameroon. PMID:27055484

  14. Increased carotid thickness in subjects with recently-diagnosed diabetes from rural Cameroon.

    Directory of Open Access Journals (Sweden)

    Nicola Napoli

    Full Text Available BACKGROUND: We have recently shown a high prevalence of diabetes and obesity in rural Cameroon, despite an improved lifestyle. Diabetes in rural Africa remains underdiagnosed and its role in increasing risk of atherosclerosis in these populations is unknown. We investigated the prevalence of carotid atherosclerosis and cardiovascular risk factors in a population of subjects with recently-diagnosed diabetes from rural Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: In a case-control study, carotid intima-media thickness (IMT was measured in 74 subjects with diabetes (diagnosed 0.9 mm was found in 4%, 45.9% and 20% of diabetic subjects at the common, bulb or internal carotid, respectively. Only 25% of patients had an HbA1c9%. The prevalence of diabetic subjects with abnormal levels of LDL-cholesterol, triglycerides, HDL-cholesterol or blood pressure was 45%, 16.6%, 15% and 65.7%, respectively. CONCLUSIONS: Carotid thickness is increased in subjects with diabetes from a rural area of Cameroon, despite the relatively recent diagnosis. These findings and the high rate of uncontrolled diabetes in this population support the increasing concern of diabetes and cardiovascular diseases in African countries and indicate the need for multifaceted health interventions in urban and rural settings.

  15. Increased Carotid Thickness in Subjects with Recently-Diagnosed Diabetes from Rural Cameroon

    Science.gov (United States)

    Napoli, Nicola; Zardi, Enrico; Strollo, Rocky; Arigliani, Michele; Daverio, Andrea; Olearo, Flaminia; Tosi, Daniele; Dicuonzo, Giordano; Scarpa, Filomena; Pedone, Claudio; Tegue Simo, Hervé Hilaire; Mottini, Giovanni; Pozzilli, Paolo

    2012-01-01

    Background We have recently shown a high prevalence of diabetes and obesity in rural Cameroon, despite an improved lifestyle. Diabetes in rural Africa remains underdiagnosed and its role in increasing risk of atherosclerosis in these populations is unknown. We investigated the prevalence of carotid atherosclerosis and cardiovascular risk factors in a population of subjects with recently-diagnosed diabetes from rural Cameroon. Methodology/Principal Findings In a case-control study, carotid intima-media thickness (IMT) was measured in 74 subjects with diabetes (diagnosed 0.9 mm was found in 4%, 45.9% and 20% of diabetic subjects at the common, bulb or internal carotid, respectively. Only 25% of patients had an HbA1c9%). The prevalence of diabetic subjects with abnormal levels of LDL-cholesterol, triglycerides, HDL-cholesterol or blood pressure was 45%, 16.6%, 15% and 65.7%, respectively. Conclusions Carotid thickness is increased in subjects with diabetes from a rural area of Cameroon, despite the relatively recent diagnosis. These findings and the high rate of uncontrolled diabetes in this population support the increasing concern of diabetes and cardiovascular diseases in African countries and indicate the need for multifaceted health interventions in urban and rural settings. PMID:22916106

  16. Conservation Concern for the Deteriorating Geographical Range of the Grey Parrot in Cameroon

    Directory of Open Access Journals (Sweden)

    Simon A. Tamungang

    2014-01-01

    Full Text Available The need for information on Grey Parrot distribution and vegetation associations for informed management and policy decisions was the basis for this study. A nationwide survey of the Grey Parrot population and habitat status was carried out, using questionnaire and point count methods. From the results, the extent of the contemporary range of the parrots was restricted to Southern Cameroon, which harbours the rainforest. Regional parrot population means ranged from 3,487 parrots in the Littoral to 1,351,275 parrots in the East Regions. The extent of the contemporary range as a percentage of the whole country was 25.4% and as a percentage of the regions with rainforest was 44.5%. The historic range of the bird has been reduced by over 55.5%. Estimated percentage of forest lost per region ranged from 20.4% in the Centre to 57.1% in the East and South Regions. At a global level, Cameroon contributed 9% to the total extent of the range of the Grey Parrot in Africa. The range is increasingly fragmented, contracted, and lost through land-based socioeconomic activities. These degradation pressures on the range called for urgent conservation considerations for long-term survival of the parrot species and its associated biodiversity in Cameroon.

  17. Oil depletion and development in Cameroon: A critical appraisal of the permanent income hypothesis

    Energy Technology Data Exchange (ETDEWEB)

    Djiofack, Calvin Z., E-mail: cdjiofack@worldbank.org [World Bank, Latin America and Caribbean, 1818 H Street, NW Washington, DC 20433 (United States); Omgba, Luc Desire, E-mail: Desire.OMGBA@supco-amiens.fr [Amiens School of Management, 18, Place Saint Michel-80038 Amiens Cedex 1 (France)

    2011-11-15

    This paper focuses on medium term policy options in the economic context of natural resource depletion. In particular, a novel approach for analyzing the impact of the permanent income hypothesis (PIH) with a dynamic recursive computable general equilibrium (CGE) model is employed. The model is benchmarked in an oil producing country with declining production, namely Cameroon. The results show that the PIH renders public finances less vulnerable during the post-oil transition. However, adopting the PIH is not associated with substantial improvements in growth and household welfare in Cameroon. Therefore, the PIH cannot be the only basis for better management of oil revenues in the country. - Highlights: > We assess for the first time, the adoption of permanent income hypothesis (PIH) in a dynamic CGE model. > The model is benchmarked in an oil country with declining production, namely Cameroon. > PIH renders public finances less vulnerable during the post-oil transition. > However, adopting the PIH is not associated with significant improvement of the growth and households' welfare.

  18. Distribution and heterogeneity of hepatitis C genotypes in hepatitis patients in Cameroon.

    Science.gov (United States)

    Pasquier, Christophe; Njouom, Richard; Ayouba, Ahidjo; Dubois, Martine; Sartre, Michèle Tagni; Vessière, Aurelia; Timba, Isabelle; Thonnon, Jocelyn; Izopet, Jacques; Nerrienet, Eric

    2005-11-01

    Hepatitis C virus infects humans world-wide. The virus genome varies greatly and it has several genotypes. HCV infection is highly prevalent in Central Africa and Cameroon. Initial studies on the genetic variability of HCV showed infection with HCV genotypes 1, 2, and 4. We have now sequenced the NS5b and E2 regions of 156 HCV isolates collected from patients presenting for diagnosis in Yaounde and used the data to describe the distribution of HCV genotypes and subtypes in patients with hepatitis in Cameroon. Genotype 1 was more frequent than Genotypes 4 and 2. Genotypes 1 and 4 were highly heterogeneous, containing many subtypes described previously (1b, 1c, 1e, 1h, 1l, 4f, 4t, 4p, 4k) and unsubtyped groups. There was a systematic phylogenetic concordance between NS5b and E2 sequence clustering. The Genotype 2 sequences did not vary. Neither subject age nor gender influenced HCV distribution. HCV Genotypes 1 and 4 are very heterogeneous in Cameroon, perhaps due to ancient infections. The homogeneity of HCV Genotype 2 indicates its more recent introduction from western Africa.

  19. Unilateral childhood blindness: a hospital-based study in Yaoundé, Cameroon

    Directory of Open Access Journals (Sweden)

    André; Omgbwa Eballe

    2009-08-01

    Full Text Available André Omgbwa Eballe1, Emilienne Epée2, Godefroy Koki2, Lucienne Bella2, Côme Ebana Mvogo21Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon; 2Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, CameroonIntroduction: We performed an analytic and prospective study over a period of 12 months from January 2nd to December 31st, 2008, at the Gynaeco-Obstetric and Paediatric Hospital of Yaoundé, Cameroon. Our aim was to determine the prevalence and causes of unilateral blindness in school children aged 6 to 15 years.Results: Among the 1,266 children aged 6 to 15 years who were recruited, 60 presented with unilateral blindness (4.7%: 42 boys (6.96% and 18 girls (2.71%. The mean age was 10.15 ± 3.4 years. In patients with unilateral blindness, 65% was due to ocular trauma.Discussion: The hospital-based prevalence of unilateral blindness in children is relatively high and ocular trauma is the leading etiology.Conclusion: Unilateral blindness in school children is avoidable and its incidence could be markedly reduced by emphasizing an information strategy and education based on prevention of ocular trauma. Early management of nontraumatic diseases such as infantile glaucoma and some tumors could improve outcome and avoid blindness.Keywords: unilateral blindness, ocular trauma, prevalence, education

  20. Epidemiology of chicken anemia virus in Central African Republic and Cameroon

    Directory of Open Access Journals (Sweden)

    Snoeck Chantal J

    2012-09-01

    Full Text Available Abstract Background Although chicken anemia virus (CAV has been detected on all continents, little is known about this virus in sub-Saharan Africa. This study aimed to detect and characterize CAV for the first time in Central African Republic and in Cameroon. Results An overall flock seroprevalence of 36.7% was found in Central African Republic during the 2008–2010 period. Virus prevalences were 34.2% (2008, 14.3% (2009 and 10.4% (2010 in Central African Republic and 39% (2007 and 34.9% (2009 in Cameroon. CAV DNA was found in cloacal swabs of 76.9% of seropositive chickens, suggesting that these animals excreted the virus despite antibodies. On the basis of VP1 sequences, most of the strains in Central African Republic and Cameroon belonged to 9 distinct phylogenetic clusters at the nucleotide level and were not intermixed with strains from other continent. Several cases of mixed infections in flocks and individual chickens were identified. Conclusions Our results suggest multiple introductions of CAV in each country that later spread and diverged locally. Mixed genotype infections together with the observation of CAV DNA in cloacal samples despite antibodies suggest a suboptimal protection by antibodies or virus persistence.

  1. Distribution and heterogeneity of hepatitis C genotypes in hepatitis patients in Cameroon.

    Science.gov (United States)

    Pasquier, Christophe; Njouom, Richard; Ayouba, Ahidjo; Dubois, Martine; Sartre, Michèle Tagni; Vessière, Aurelia; Timba, Isabelle; Thonnon, Jocelyn; Izopet, Jacques; Nerrienet, Eric

    2005-11-01

    Hepatitis C virus infects humans world-wide. The virus genome varies greatly and it has several genotypes. HCV infection is highly prevalent in Central Africa and Cameroon. Initial studies on the genetic variability of HCV showed infection with HCV genotypes 1, 2, and 4. We have now sequenced the NS5b and E2 regions of 156 HCV isolates collected from patients presenting for diagnosis in Yaounde and used the data to describe the distribution of HCV genotypes and subtypes in patients with hepatitis in Cameroon. Genotype 1 was more frequent than Genotypes 4 and 2. Genotypes 1 and 4 were highly heterogeneous, containing many subtypes described previously (1b, 1c, 1e, 1h, 1l, 4f, 4t, 4p, 4k) and unsubtyped groups. There was a systematic phylogenetic concordance between NS5b and E2 sequence clustering. The Genotype 2 sequences did not vary. Neither subject age nor gender influenced HCV distribution. HCV Genotypes 1 and 4 are very heterogeneous in Cameroon, perhaps due to ancient infections. The homogeneity of HCV Genotype 2 indicates its more recent introduction from western Africa. PMID:16173014

  2. A low proportion of HBeAg among HBsAg-positive pregnant women with known HIV status could suggest low perinatal transmission of HBV in Cameroon

    Directory of Open Access Journals (Sweden)

    Kfutwah Anfumbom KW

    2012-03-01

    Full Text Available Abstract Background Transmission of hepatitis B virus (HBV from HBV-positive mothers to their infants is common and usually occurs when the mother is hepatitis B e antigen (HBeAg positive and/or has a high HBV DNA load. In this study, we determined the prevalence of hepatitis B surface antigen (HBsAg and HBeAg among pregnant women with known HIV status. Findings A total of 650 pregnant women with a mean age of 26.2 years including 301 HIV-positives and 349 HIV-negatives were screened for HBsAg (Monolisa AgHBs Plus Biorad, France. Among the HBsAg-positives, HBeAg and anti-HBe were tested (Monolisa Ag HBe Plus Biorad, France. Overall, 51 (7.85% were positive for HBsAg. The prevalence of HBsAg was not statistically different between HIV-positive and HIV-negative pregnant women [28/301 (9.3% vs 23/349 (6.59%; p = 0.2]. None of the 45 HBsAg-positive samples was reactive for HBeAg. Conclusions Our study indicates a high prevalence of HBsAg with very low proportion of HBeAg in Cameroonian pregnant women. Since perinatal transmission of HBV is mostly effective when the mother is also HBeAg-positive, our data could suggest that perinatal transmissions play a minor role in HBV prevalence in Cameroon. In line with previous African studies, these findings further suggests that horizontal transmission could be the most common mechanism of HBV infections in Cameroon.

  3. Treatment of malaria from monotherapy to artemisinin-based combination therapy by health professionals in rural health facilities in southern Cameroon

    Directory of Open Access Journals (Sweden)

    Bley Daniel

    2009-07-01

    Full Text Available Abstract Background One year after the adoption of artesunate-amodiaquine (AS/AQ as first-line therapy for the treatment of uncomplicated malaria, this study was designed to assess the treatment practices regarding anti-malarial drugs at health facilities in four rural areas in southern Cameroon. Methods Between April and August 2005, information was collected by interviewing fifty-two health professionals from twelve rural health facilities, using a structured questionnaire. Results In 2005, only three anti-malarial drugs were used in rural health facilities, including: amodiaquine, quinine and sulphadoxine-pyrimethamine. Only 2.0% of the health professionals prescribed the recommended AS/AQ combination. After reading the treatment guidelines, 75.0% were in favour of the treatment protocol with the following limitations: lack of paediatric formulations, high cost and large number of tablets per day. Up to 21.0% of professionals did not prescribe AS/AQ because of the level of adverse events attributed to the use of amodiaquine as monotherapy. Conclusion The present study indicates that AS/AQ was not available in the public health facilities at the time of the study, and health practitioners were not informed about the new treatment guidelines. Results of qualitative analysis suggest that prescribers should be involved as soon as possible in projects related to the optimization of treatment guidelines and comply with new drugs. Adapted formulations should be made available at the international level and implemented locally before new drugs and treatments are proposed through a national control programme. This baseline information will be useful to monitor progresses in the implementation of artemisinin-based combination therapy in Cameroon.

  4. Feasibility of pico-hydro and photovoltaic hybrid power systems for remote villages in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Nfah, E.M. [Laboratoire d' Automatique et d' Informatique Appliquee, I.U.T. Fotso Victor, P.O. Box 134, Bandjoun, University of Dschang (Cameroon); Ngundam, J.M. [Automation and Control Laboratory, School of Engineering, P.O. Box 8390, University of Yaounde I (Cameroon)

    2009-06-15

    Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been simulated for remote villages in Cameroon using a load of 73 kWh/day and 8.3 kWp. Renewable energy systems were simulated using HOMER, the load profile of a hostel in Cameroon, the solar insolation of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be either 0.352 EUR/kWh for a 5 kW pico-hydro generator with 72 kWh storage or 0.396 EUR/kWh for a 3 kWp photovoltaic generator with 36 kWh storage. These energy costs were obtained with a biomass resource cost of 25 EUR/tonne. The pH and PV hybrid systems both required the parallel operation of a 3.3 kW battery inverter with a 10 kW biogas generator. The pH/biogas/battery systems simulated for villages located in the south of Cameroon with a flow rate of at least 92 l/s produced lower energy costs than PV/biogas/battery systems simulated for villages in the north of Cameroon with an insolation level of at least 5.55 kWh/m{sup 2}/day. For a single-wire grid extension cost of 5000 EUR/km, operation and maintenance costs of 125 EUR/yr/km and a grid power price of 0.1 EUR/kWh, the breakeven grid extension distances were found to be 12.9 km for pH/biogas/battery systems and 15.2 km for PV/biogas/battery systems respectively. Investments in biogas based renewable energy systems could thus be considered in the National Energy Action Plan of Cameroon for the supply of energy to key sectors involved in poverty alleviation. (author)

  5. Guanamiru, l'homme-volcan

    OpenAIRE

    Collot, Michel

    2016-01-01

    Comment fabriquer un volcan portatif ? Où trouver un cratère en kit ? Comment faut-il l’emballer pour qu’il supporte un voyage transcontinental ? Où peut-on assister à des éruptions de charité ? Comment devient-on un homme-volcan ? Y a-t-il un remède contre les crises de mégalomanie éruptive ? A toutes ces questions brûlantes, Supervielle a tenté de répondre dans son premier roman, L'Homme de la pampa. C’est l’époque où, après avoir refoulé pendant près de quarante ans sous une croûte épaisse...

  6. Anomalous diffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2015-01-01

    Volcanic seismicity at Mt. Etna is studied. It is found that the associated stochastic process exhibits a subdiffusive phenomenon. The jump probability distribution well obeys an exponential law, whereas the waiting-time distribution follows a power law in a wide range. Although these results would seem to suggest that the phenomenon could be described by temporally-fractional kinetic theory based on the viewpoint of continuous-time random walks, the exponent of the power-law waiting-time distribution actually lies outside of the range allowed in the theory. In addition, there exists the aging phenomenon in the event-time averaged mean squared displacement, in contrast to the picture of fractional Brownian motion. Comments are also made on possible relevances of random walks on fractals as well as nonlinear kinetics. Thus, problems of volcanic seismicity are highly challenging for science of complex systems.

  7. Source mechanisms of volcanic tsunamis.

    Science.gov (United States)

    Paris, Raphaël

    2015-10-28

    Volcanic tsunamis are generated by a variety of mechanisms, including volcano-tectonic earthquakes, slope instabilities, pyroclastic flows, underwater explosions, shock waves and caldera collapse. In this review, we focus on the lessons that can be learnt from past events and address the influence of parameters such as volume flux of mass flows, explosion energy or duration of caldera collapse on tsunami generation. The diversity of waves in terms of amplitude, period, form, dispersion, etc. poses difficulties for integration and harmonization of sources to be used for numerical models and probabilistic tsunami hazard maps. In many cases, monitoring and warning of volcanic tsunamis remain challenging (further technical and scientific developments being necessary) and must be coupled with policies of population preparedness.

  8. Understanding Volcanic Conduit Dynamics: from Experimental Fragmentation to Volcanic Eruptions

    Science.gov (United States)

    Arciniega-Ceballos, A.; Alatorre-Ibarguengoitia, M. A.; Scheu, B.; Dingwell, D. B.

    2011-12-01

    The investigation of conduit dynamics at high pressure, under controlled laboratory conditions is a powerful tool to understand the physics behind volcanic processes before an eruption. In this work, we analyze the characteristics of the seismic response of an "experimental volcano" focusing on the dynamics of the conduit behavior during the fragmentation process of volcanic rocks. The "experimental volcano" is represented by a shock tube apparatus, which consists of a low-pressure voluminous tank (3 x 0.40 m), for sample recovery; and a high-pressure pipe-like conduit (16.5 x 2,5 cm), which represents the volcanic source mechanism, where rock samples are pressurized and fragmented. These two serial steel pipes are connected and sealed by a set of diaphragms that bear pressures in a range of 4 to 20 MPa. The history of the overall process of an explosion consists of four steps: 1) the slow pressurization of the pipe-like conduit filled with solid pumice and gas, 2) the sudden removal of the diaphragms, 3) the rapid decompression of the system and 4) the ejection of the gas-particle mixture. Each step imprints distinctive features on the microseismic records, reflecting the conduit dynamics during the explosion. In this work we show how features such as waveform characteristics, the three components of the force system acting on the conduit, the independent components of the moment tensor, the volumetric change of the source mechanism, the arrival time of the shock wave and its velocity, are quantified from the experimental microseismic data. Knowing these features, each step of the eruptive process, the conduit conditions and the source mechanism characteristics can be determined. The procedure applied in this experimental approach allows the use of seismic field data to estimate volcanic conduit conditions before an eruption takes place. We state on the hypothesis that the physics behind the pressurization and depressurization process of any conduit is the same

  9. Amazonian volcanic activity at the Syrtis volcanic province, Mars

    Science.gov (United States)

    Platz, Thomas; Jodlowski, Piotr; Fawdon, Peter; Michael, Greg; Tanaka, Kenneth

    2014-05-01

    The Syrtis Major volcanic province, including the entire Syrtis Major Planum, is located near the Martian highland/lowland transitional zone west of Isidis Planitia. It covers ≡7.4×105 km2 and contains two low-shield volcanic edifices with N-S elongated calderas named Nili and Meroe Paterae. The estimated thickness of erupted material in the province ranges from approximately 0.5 km to 1.0 km with a total volume of about 1.6-3.2×105 km3 [1]. The timing of volcanic activity in the Syrtis Major volcanic province has been suggested to be restricted to the Hesperian Period [1-4]. In the geological map of Greeley and Guest [2], volcanic material of Syrtis Major was assigned an Hesperian age based on the density of observed craters larger than 5 km in diameter. Using the same crater density range, recent studies of Hiesinger et al. [1] and Tanaka et al. [3] and Tanaka et al. [4] assigned an Early Hesperian and Early to Late Hesperian age, respectively, for the entire province. In this study we mapped lava flows, lava channels, and major lava-flow margins and report model ages for lava-flow formation and caldera segments of Nili and Meroe Paterae. The objective of this ongoing survey is to better understand the eruption frequency of this volcanic province. In total, we mapped 67 lava flows, caldera segments, and intra-crater fillings of which 55 were dated. Crater size-frequency distributions (CSFD) were mapped on HRSC and CTX imagery using CraterTools [5]. CSFDs were analyzed and model ages determined in Craterstats [6] using the production and chronology functions of Ivanov [7] and Hartmann and Neukum [8], respectively. A detailed description of the utilization of the crater-counting technique and its limitations with respect to small-scale mapping is given in Platz et al. [9]. Model ages range between 838 Ma (Middle Amazonian) to 3.6 Ga (Late Hesperian). In our survey, a broad age peak occurs between 2 to 2.6 Ga, continuously declining thereafter. We note that

  10. Uranium deposits in volcanic rocks

    International Nuclear Information System (INIS)

    Twenty-eight papers were presented at the meeting and two additional papers were provided. Three panels were organized to consider the specific aspects of the genesis of uranium deposits in volcanic rocks, recognition criteria for the characterization of such deposits, and approaches to exploration. The papers presented and the findings of the panels are included in the Proceedings. Separate abstracts were prepared for each of these papers

  11. Volcanism in Elysium Planitia, Mars

    Science.gov (United States)

    Mouginis-Mark, P. J.

    1984-01-01

    Geomorphic mapping revealed that the three volcanic constructs within Elysium Planitia (Hecates Tholus, elysium Mons and Albor Tholus) are very different in their overall morphology and represent three distinct types of martian volcano. Hecates Tholus was found to possess the most likely possible example of a young, explosively generated, air fall deposit, while the volume of magma erupted from Elysium Mons appears to have been orders of magnitude larger than that erupted from Albor Tholus. A primary aim of the regional geological analysis of Elysium Planitia is to further understand the volcanic and tectonic evolution of the area by the identification and interpretation of individual lava flows and their source vents. Lava flow size, spatial distribution, flow direction and the stratigraphic relationships of these lava flows to adjacent structural features were all measured. The topographic form of Elysium Mons has totally controlled the flow direction of lava flows within Elysium Planitia. Lava flows from Elysium Mons can be traced for distances of 150 to 250 km in a radial direction from the volcano. Parasitic vents located beyond the recognizable volcanic construct also conform to this radial pattern. A second unusual characteristic of the Elysium Planitia region is the high frequency of occurrence of sinuous channels that are morphologically similar to lunar sinuous rilles.

  12. Bayesian analysis of volcanic eruptions

    Science.gov (United States)

    Ho, Chih-Hsiang

    1990-10-01

    The simple Poisson model generally gives a good fit to many volcanoes for volcanic eruption forecasting. Nonetheless, empirical evidence suggests that volcanic activity in successive equal time-periods tends to be more variable than a simple Poisson with constant eruptive rate. An alternative model is therefore examined in which eruptive rate(λ) for a given volcano or cluster(s) of volcanoes is described by a gamma distribution (prior) rather than treated as a constant value as in the assumptions of a simple Poisson model. Bayesian analysis is performed to link two distributions together to give the aggregate behavior of the volcanic activity. When the Poisson process is expanded to accomodate a gamma mixing distribution on λ, a consequence of this mixed (or compound) Poisson model is that the frequency distribution of eruptions in any given time-period of equal length follows the negative binomial distribution (NBD). Applications of the proposed model and comparisons between the generalized model and simple Poisson model are discussed based on the historical eruptive count data of volcanoes Mauna Loa (Hawaii) and Etna (Italy). Several relevant facts lead to the conclusion that the generalized model is preferable for practical use both in space and time.

  13. Reappraisal of the significance of volcanic fields

    Science.gov (United States)

    Cañón-Tapia, Edgardo

    2016-01-01

    "Volcanic field" is a term commonly used to loosely describe a group of volcanoes. Often, it is implicitly assumed that the volcanoes on a volcanic field are small, monogenetic and dominantly basaltic, but none of those attributes is indispensable on some definitions of the term. Actually, the term "volcanic field" can be used to describe a group of purely monogenetic edifices, a group of mixed monogenetic and polygenetic edifices, or even a group formed only by purely polygenetic edifices. Differences between each of those alternatives might be important, but the extent to which those differences are truly relevant remains still to be explored. Furthermore, there are several limitations on the current knowledge of this type of volcanic activity that explain the lack of a comprehensive effort to study volcanic fields in global contexts. In this work, issues concerning current definitions of a volcanic field are examined, and some criteria that can be used to distinguish volcanic fields from non-field volcanoes are suggested. Special attention is given to the role played by spatial scale on such a distinction. Also, the tectonic implications of their spatial distribution are explored. In particular, it is shown that volcanic fields are an important component of volcanic activity at a global scale that is closely associated to diffuse plate boundaries, and might well be considered the archetypical volcanic form of such tectonic scenarios.

  14. Addressing the concerns of rural communities about access to plants and knowledge in a sui generis legislation in Cameroon

    Indian Academy of Sciences (India)

    Marcelin Tonye Mahop

    2004-12-01

    This article assesses the traditional systems of accessing and using plant genetic resources as well as the benefit sharing and systems of sanctioning infringement in the context of biodiversity related activities in specific areas in the Northwest province of Cameroon. The article also addresses the type research and development activities using plant genetic resources and associated traditional knowledge in the context of Cameroon, the current laws regulating such activities and the extent to which these activities and laws affect and/or protect the customary biodiversity rights of rural communities. The article uses these assessments to suggest the context under which a sui generis legislation for the protection of the biodiversity rights of rural communities can be established in Cameroon.

  15. Assessing health impacts of the Chad-Cameroon petroleum development and pipeline project: challenges and a way forward

    International Nuclear Information System (INIS)

    Health impact assessment (HIA) of projects, programmes and policies is increasingly recognized as a powerful methodology for mitigating negative health impacts and enhancing equitable and sustainable development, yet applications in the developing world are sparse. Here, we focus on a large infrastructure development in sub-Saharan Africa, namely the Chad-Cameroon petroleum development and pipeline project. We adapted a five-step process for HIA, consisting of (1) screening of project documents, (2) profiling of affected communities, (3) identifying priority health areas, predicting potential impacts, and proposing mitigation measures, (4) implementing interventions, and (5) monitoring and evaluation of health impacts. We found that project scoping was broad, including extensive environmental and social assessments. Innovative features of the project include the high degree of public-private partnerships, and the management of oil revenues for purposes of poverty reduction. The project also addressed occupational and public health issues, and developed and implemented measures to prevent or mitigate potential health impacts. However, there was a disproportionate emphasis on workers' health, particularly on the prevention/mitigation of construction-related injuries, sexually transmitted infections (STIs; mainly HIV/AIDS), and malaria. Health impacts among surrounding communities, and cumulative health impacts in the larger region were not considered in a comprehensive way. Concluding, there is a need for a more systemic approach to HIA and its incorporation within 'Equator Principles', which are increasingly adopted by the international financial community. This process would include clarification of corporate social responsibility beyond the project fence line in the mitigation of health problems at regional levels. Finally, we propose the establishment and running of a longitudinal demographic surveillance system, which--coupled with regular household surveys

  16. DIVERSITY, STRUCTURAL PARAMETERS AND NON-TIMBER FOREST PRODUCTS IN THE FOREST RESERVE OF BONEPOUPA (DOUALA, CAMEROON

    Directory of Open Access Journals (Sweden)

    Jean Paul Kamdem

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812363In order to come up with a sustainable use of forest ecosystems in Cameroon, its vegetal diversity has been inventoried; the plant potentials and the structural parameters were studied in the forest reserve of Bonepoupa. Ten non-continuous plots of 200 m² were done and the materialization of the lines was done with a topofil put at the centre of the field with ropes at 5 m each of the topofil. In addition, ninety people were interviewed in order to know the potential use of species in this region. Up to 172 individuals with Diameter at Breast Height (DBH ≥ 5 cm divided into 27 species, 25 genera and 18 families were inventoried and the coefficient of abundance-dominance was determined. The diversity index of Shannon (H’ was H’1 = 4.17 ± 0.45 with H’1max = 4.75 and the evenness was R1 = 0.88. Taking into account herbaceous species, H’ determined by the coefficient of abundance-dominance was H’2 = 4.74 ± 0.56 with H’2max = 5.70 and the evenness  was  R2 = 0.83. The  total  basal  area  was 19.69 m2/ha and the density was 860 individuals/ha. These results indicate that herbaceous significantly modifies the value of the diversity index and that forest reserve of Bonepoupa is experiencing a problem of conservation which is due to a lack of its appropriate management. The knowledge of non-timber forest products and their use as food as well as medicinal resources by local population might be helpful for the sustainable management of resources in this forest reserve.

  17. Volcanic processes in the Solar System

    Science.gov (United States)

    Carr, M.H.

    1987-01-01

    This article stresses that terrestrial volcanism represents only part of the range of volcanism in the solar system. Earth processes of volcanicity are dominated by plate tectonics, which does not seem to operate on other planets, except possibly on Venus. Lunar volcanicity is dominated by lava effusion at enormous rates. Mars is similar, with the addition to huge shield volcanoes developed over fixed hotspots. Io, the moon closest to Jupiter, is the most active body in the Solar System and, for example, much sulphur and silicates are emitted. The eruptions of Io are generated by heating caused by tides induced by Jupiter. Europa nearby seems to emit water from fractures and Ganymede is similar. The satellites of Saturn and Uranus are also marked by volcanic craters, but they are of very low temperature melts, possibly of ammonia and water. The volcanism of the solar system is generally more exotic, the greater the distance from Earth. -A.Scarth

  18. Volcanic caves of East Africa - an overview

    OpenAIRE

    Jim W. Simons

    1998-01-01

    Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA) for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and are...

  19. Nephelometric Dropsonde for Volcanic Ash Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced dropsondes that could effectively be guided through atmospheric regions of interest such as volcanic plumes could enable unprecedented observations of...

  20. Long-lived explosive volcanism on Mercury

    OpenAIRE

    Thomas, Rebecca J.; Rothery, David A.; Conway, Susan J.; Anand, Mahesh

    2014-01-01

    The duration and timing of volcanic activity on Mercury are key indicators of the thermal evolution of the planet and provide a valuable comparative example for other terrestrial bodies. The majority of effusive volcanism on Mercury appears to have occurred early in the planet's geological history (~4.1–3.55 Ga), but there is also evidence for explosive volcanism. Here we present evidence that explosive volcanism occurred from at least 3.9 Ga until less than a billion years ago and so was sub...

  1. Catastrophic volcanic collapse: relation to hydrothermal processes.

    Science.gov (United States)

    López, D L; Williams, S N

    1993-06-18

    Catastrophic volcanic collapse, without precursory magmatic activity, is characteristic of many volcanic disasters. The extent and locations of hydrothermal discharges at Nevado del Ruiz volcano, Colombia, suggest that at many volcanoes collapse may result from the interactions between hydrothermal fluids and the volcanic edifice. Rock dissolution and hydrothermal mineral alteration, combined with physical triggers such as earth-quakes, can produce volcanic collapse. Hot spring water compositions, residence times, and flow paths through faults were used to model potential collapse at Ruiz. Caldera dimensions, deposits, and alteration mineral volumes are consistent with parameters observed at other volcanoes.

  2. Volcanic hazards and public response

    Science.gov (United States)

    Peterson, Donald W.

    1988-05-01

    Although scientific understanding of volcanoes is advancing, eruptions continue to take a substantial toll of life and property. Some of these losses could be reduced by better advance preparation, more effective flow of information between scientists and public officials, and better understanding of volcanic behavior by all segments of the public. The greatest losses generally occur at volcanoes that erupt infrequently where people are not accustomed to dealing with them. Scientists sometimes tend to feel that the blame for poor decisions in emergency management lies chiefly with officials or journalists because of their failure to understand the threat. However, the underlying problem embraces a set of more complex issues comprising three pervasive factors. The first factor is the volcano: signals given by restless volcanoes are often ambiguous and difficult to interpret, especially at long-quiescent volcanoes. The second factor is people: people confront hazardous volcanoes in widely divergent ways, and many have difficulty in dealing with the uncertainties inherent in volcanic unrest. The third factor is the scientists: volcanologists correctly place their highest priority on monitoring and hazard assessment, but they sometimes fail to explain clearly their conclusions to responsible officials and the public, which may lead to inadequate public response. Of all groups in society, volcanologists have the clearest understanding of the hazards and vagaries of volcanic activity; they thereby assume an ethical obligation to convey effectively their knowledge to benefit all of society. If society resists, their obligation nevertheless remains. They must use the same ingenuity and creativity in dealing with information for the public that they use in solving scientific problems. When this falls short, even excellent scientific results may be nullified.

  3. Thermal vesiculation during volcanic eruptions.

    Science.gov (United States)

    Lavallée, Yan; Dingwell, Donald B; Johnson, Jeffrey B; Cimarelli, Corrado; Hornby, Adrian J; Kendrick, Jackie E; von Aulock, Felix W; Kennedy, Ben M; Andrews, Benjamin J; Wadsworth, Fabian B; Rhodes, Emma; Chigna, Gustavo

    2015-12-24

    Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma. The development of vesicularity also greatly reduces the 'strength' of magma, a material parameter controlling fragmentation and thus the explosive potential of the liquid rock. The development of vesicularity in magmas has until now been viewed (both thermodynamically and kinetically) in terms of the pressure dependence of the solubility of water in the magma, and its role in driving gas saturation, exsolution and expansion during decompression. In contrast, the possible effects of the well documented negative temperature dependence of solubility of water in magma has largely been ignored. Recently, petrological constraints have demonstrated that considerable heating of magma may indeed be a common result of the latent heat of crystallization as well as viscous and frictional heating in areas of strain localization. Here we present field and experimental observations of magma vesiculation and fragmentation resulting from heating (rather than decompression). Textural analysis of volcanic ash from Santiaguito volcano in Guatemala reveals the presence of chemically heterogeneous filaments hosting micrometre-scale vesicles. The textures mirror those developed by disequilibrium melting induced via rapid heating during fault friction experiments, demonstrating that friction can generate sufficient heat to induce melting and vesiculation of hydrated silicic magma. Consideration of the experimentally determined temperature and pressure dependence of water solubility in magma reveals that, for many ascent paths, exsolution may be more efficiently achieved by heating than by decompression. We conclude that the thermal path experienced by magma during ascent strongly controls degassing, vesiculation, magma strength and the effusive

  4. Thermal vesiculation during volcanic eruptions

    Science.gov (United States)

    Lavallée, Yan; Dingwell, Donald B.; Johnson, Jeffrey B.; Cimarelli, Corrado; Hornby, Adrian J.; Kendrick, Jackie E.; von Aulock, Felix W.; Kennedy, Ben M.; Andrews, Benjamin J.; Wadsworth, Fabian B.; Rhodes, Emma; Chigna, Gustavo

    2015-12-01

    Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma. The development of vesicularity also greatly reduces the ‘strength’ of magma, a material parameter controlling fragmentation and thus the explosive potential of the liquid rock. The development of vesicularity in magmas has until now been viewed (both thermodynamically and kinetically) in terms of the pressure dependence of the solubility of water in the magma, and its role in driving gas saturation, exsolution and expansion during decompression. In contrast, the possible effects of the well documented negative temperature dependence of solubility of water in magma has largely been ignored. Recently, petrological constraints have demonstrated that considerable heating of magma may indeed be a common result of the latent heat of crystallization as well as viscous and frictional heating in areas of strain localization. Here we present field and experimental observations of magma vesiculation and fragmentation resulting from heating (rather than decompression). Textural analysis of volcanic ash from Santiaguito volcano in Guatemala reveals the presence of chemically heterogeneous filaments hosting micrometre-scale vesicles. The textures mirror those developed by disequilibrium melting induced via rapid heating during fault friction experiments, demonstrating that friction can generate sufficient heat to induce melting and vesiculation of hydrated silicic magma. Consideration of the experimentally determined temperature and pressure dependence of water solubility in magma reveals that, for many ascent paths, exsolution may be more efficiently achieved by heating than by decompression. We conclude that the thermal path experienced by magma during ascent strongly controls degassing, vesiculation, magma strength and the effusive

  5. Water in volcanic glass: From volcanic degassing to secondary hydration

    Science.gov (United States)

    Seligman, Angela N.; Bindeman, Ilya N.; Watkins, James M.; Ross, Abigail M.

    2016-10-01

    Volcanic glass is deposited with trace amounts (0.1-0.6 wt.%) of undegassed magmatic water dissolved in the glass. After deposition, meteoric water penetrates into the glass structure mostly as molecular H2O. Due to the lower δD (‰) values of non-tropical meteoric waters and the ∼30‰ offset between volcanic glass and environmental water during hydration, secondary water imparts lighter hydrogen isotopic values during secondary hydration up to a saturation concentration of 3-4 wt.% H2O. We analyzed compositionally and globally diverse volcanic glass from 0 to 10 ka for their δD and H2Ot across different climatic zones, and thus different δD of precipitation, on a thermal conversion elemental analyzer (TCEA) furnace attached to a mass spectrometer. We find that tephrachronologically coeval rhyolite glass is hydrated faster than basaltic glass, and in the majority of glasses an increase in age and total water content leads to a decrease in δD (‰), while a few equatorial glasses have little change in δD (‰). We compute a magmatic water correction based on our non-hydrated glasses, and calculate an average 103lnαglass-water for our hydrated felsic glasses of -33‰, which is similar to the 103lnαglass-water determined by Friedman et al. (1993a) of -34‰. We also determine a smaller average 103lnαglass-water for all our mafic glasses of -23‰. We compare the δD values of water extracted from our glasses to local meteoric waters following the inclusion of a -33‰ 103lnαglass-water. We find that, following a correction for residual magmatic water based on an average δD and wt.% H2Ot of recently erupted ashes from our study, the δD value of water extracted from hydrated volcanic glass is, on average, within 4‰ of local meteoric water. To better understand the difference in hydration rates of mafic and felsic glasses, we imaged 6 tephra clasts ranging in age and chemical composition with BSE (by FEI SEM) down to a submicron resolution. Mafic tephra

  6. Molecular Species Delimitation and Morphology of Aquatic and Sub-Aquatic Bugs (Heteroptera) in Cameroon

    Science.gov (United States)

    Le Gall, Philippe; Chen, Ping-Ping; Nieser, Nico; Guilbert, Eric; Njiokou, Flobert; Marsollier, Laurent; Guégan, Jean-François; Pluot-Sigwalt, Dominique; Eyangoh, Sara; Harry, Myriam

    2016-01-01

    Aquatic and semi-aquatic bugs (Heteroptera) represent a remarkable diversity and a resurging interest has been given to documenting at the species level these insects inhabiting Cameroon in Central Africa due to their potential implication in the transmission of the bacterium Mycobacterium ulcerans, the causal agent of Buruli ulcer, an emerging human disease. A survey was carried out over two years in Cameroon. Morphological analyses were done in two steps. A first step consisted in separating the specimens based on broadly shared characters into morphotypes. The specimens were then separated into two independent batches containing each the same representation of each morphotype. One batch (309 specimens) was used by taxonomy experts on aquatic bugs for species level identification and/or to reconcile nymph with their corresponding adult species. The second batch (188 specimens) was used to define species based on the COI DNA sequences (standard sequence used for “DNA barcoding”) and using the Automatic Barcode Gap Discovery (ABGD) method. The first morphological analysis step separated the specimens into 63 different morphotypes (49 adults and 14 nymphs), which were then found to belong to 54 morphological species in the infra-orders Gerromorpha and Nepomorpha based on the species-level morphological identification, and 41–45 putative molecular species according to the gap value retained in the ABGD. Integrating morphology and “DNA barcoding” reconciled all the specimens into 62 aquatic bug species in Cameroon. Generally, we obtained a good congruence between species a priori identified based on morphology from adult morphotypes and molecular putative species. Moreover, molecular identification has allowed the association of 86% of nymphs with adults. This work illustrates the importance of integrative taxonomy. PMID:27149077

  7. Cure or control: complying with biomedical regime of diabetes in Cameroon

    Directory of Open Access Journals (Sweden)

    Unwin Nigel

    2008-02-01

    Full Text Available Abstract Background The objective of the study was to explore the cultural aspect of compliance, its underlying principles and how these cultural aspects can be used to improve patient centred care for diabetes in Cameroon. Methods We used participant observation to collect data from a rural and an urban health district of Cameroon from June 2001 to June 2003. Patients were studied in their natural settings through daily interactions with them. The analysis was inductive and a continuous process from the early stages of fieldwork. Results The ethnography revealed a lack of basic knowledge about diabetes and diabetes risk factors amongst people with diabetes. The issue of compliance was identified as one of the main themes in the process of treating diabetes. Compliance emerged as part of the discourse of healthcare providers in clinics and filtered into the daily discourses of people with diabetes. The clinical encounters offered treatment packages that were socially inappropriate therefore rejected or modified for most of the time by people with diabetes. Compliance to biomedical therapy suffered a setback for four main reasons: dealing with competing regimes of treatment; coming to terms with biomedical treatment of diabetes; the cost of biomedical therapy; and the impact of AIDS on accepting weight loss as a lifestyle measure in prescription packages. People with diabetes had fears about and negative opinions of accepting certain prescriptions that they thought could interfere with their accustomed social image especially that which had to do with bridging their relationship with ancestors and losing weight in the era of HIV/AIDS. Conclusion The cultural pressures on patients are responsible for patients' partial acceptance of and adherence to prescriptions. Understanding the self-image of patients and their background cultures are vital ingredients to improve diabetes care in low-income countries of Sub-Sahara Africa like Cameroon.

  8. Molecular Species Delimitation and Morphology of Aquatic and Sub-Aquatic Bugs (Heteroptera in Cameroon.

    Directory of Open Access Journals (Sweden)

    Solange Meyin A Ebong

    Full Text Available Aquatic and semi-aquatic bugs (Heteroptera represent a remarkable diversity and a resurging interest has been given to documenting at the species level these insects inhabiting Cameroon in Central Africa due to their potential implication in the transmission of the bacterium Mycobacterium ulcerans, the causal agent of Buruli ulcer, an emerging human disease. A survey was carried out over two years in Cameroon. Morphological analyses were done in two steps. A first step consisted in separating the specimens based on broadly shared characters into morphotypes. The specimens were then separated into two independent batches containing each the same representation of each morphotype. One batch (309 specimens was used by taxonomy experts on aquatic bugs for species level identification and/or to reconcile nymph with their corresponding adult species. The second batch (188 specimens was used to define species based on the COI DNA sequences (standard sequence used for "DNA barcoding" and using the Automatic Barcode Gap Discovery (ABGD method. The first morphological analysis step separated the specimens into 63 different morphotypes (49 adults and 14 nymphs, which were then found to belong to 54 morphological species in the infra-orders Gerromorpha and Nepomorpha based on the species-level morphological identification, and 41-45 putative molecular species according to the gap value retained in the ABGD. Integrating morphology and "DNA barcoding" reconciled all the specimens into 62 aquatic bug species in Cameroon. Generally, we obtained a good congruence between species a priori identified based on morphology from adult morphotypes and molecular putative species. Moreover, molecular identification has allowed the association of 86% of nymphs with adults. This work illustrates the importance of integrative taxonomy.

  9. Hormonal contraception, sexual behaviour and HIV prevalence among women in Cameroon

    Directory of Open Access Journals (Sweden)

    Soskolne Varda

    2008-10-01

    Full Text Available Abstract Background Data on the effect of contraceptive methods, other than the condom, on HIV acquisition is not clear. The aim of this study was to describe hormonal contraceptive use, sexual behaviour and HIV prevalence among women in Cameroon in order to provide baseline information for future analytical studies. Methods This is a cross-sectional descriptive study based a nationally representative sample of 4486 sexually active women aged 15–49 years who participated in the 2004 Cameroon Demographic and Health Survey. Results The overall HIV prevalence was 7.4% (332/4486. The HIV prevalence was higher in the 25–35 year age group (10.03%, urban residents (9.39%, and formerly married (18.48%, compared to their compatriots. The prevalence was lower in women with five or more living child (3.67%, women in the low wealth index category (3.79% and women who had no formal education (3.37%. The HIV prevalence was higher among women who had two or more partners in the last 12 months (10.26% and women who reported to have had four or more partners in their lifetime (12.40%. The prevalence of HIV was higher among current hormonal contraceptive users (6.63% compared to the current non-users (3.06%, among ever users of hormonal contraception (13.27% compared to the never users (7.11%. Conclusion We conclude that the prevalence of HIV among sexually active women in Cameroon varies according to sociodemographic characteristics, sexual behaviour and hormonal contraceptive use. Our findings underscore the need to counsel women using hormonal contraception to be aware that hormonal methods do not protect against HIV infection. Given the biologic plausibility of the link between hormonal contraception and HIV infection, future research should focus on carefully designed prospective studies to establish the temporal relationship and estimate the incidence of HIV infection among women using and not using hormonal contraceptive methods.

  10. Forest Conversion, Agricultural Transitions and the Influence of Multi-scale Market Factors in Southwest Cameroon

    Science.gov (United States)

    Ordway, E.; Lambin, E.; Asner, G. P.

    2015-12-01

    The changing structure of demand for commodities associated with food security and energy has had a startling impact on land use change in tropical forests in recent decades. Yet, the composition of conversion in the Congo basin remains a major uncertainty, particularly with regards to the scale of drivers of change. Owing to rapid expansion of production globally and longstanding historical production locally in the Congo basin, oil palm offers a lens through which to evaluate local land use decisions across a spectrum of small- to large-scales of production as well as interactions with regional and global supply chains. We examined the effect of global commodity crop expansion on land use change in Southwest Cameroon using a mixed-methods approach to integrate remote sensing, field surveys and socioeconomic data. Southwest Cameroon (2.5 Mha) has a long history of large- and small-scale agriculture, ranging from mixed crop subsistence agriculture to large monocrop plantations of oil palm, cocoa, and rubber. Trends and spatial patterns of forest conversion and agricultural transitions were analyzed from 2000-2015 using satellite imagery. We used economic, demographic and field survey datasets to assess how regional and global market factors and local commodity crop decisions affect land use patterns. Our results show that oil palm is a major commodity crop expanding in this region, and that conversion is occurring primarily through expansion by medium-scale producers and local elites. Results also indicate that global and regional supply chain dynamics influence local land use decision making. This research contributes new information on land use patterns and dynamics in the Congo basin, an understudied region. More specifically, results from this research contribute information on recent trends of oil palm expansion in Cameroon that will be used in national land use planning strategies.

  11. Early Infant Male Circumcision in Cameroon and Senegal: Demand, Service Provision, and Cultural Context

    Science.gov (United States)

    Kenu, Ernest; Sint, Tin Tin; Kamenga, Claude; Ekpini, Rene

    2016-01-01

    ABSTRACT Background: Male circumcision is almost universal in North and West Africa, and practiced for various reasons. Yet there is little documentation on service delivery, clinical procedures, policies, and programmatic strategies. The United Nations Children’s Fund (UNICEF) commissioned country program reviews in 2014 to shed light on the delivery of male circumcision services for infants in Cameroon and Senegal. Methods: We conducted a policy desk review, key informant interviews, and focus group discussions at health centers and in communities. Between December 2014 and January 2015, we conducted 21 key informant interviews (13 with regional and district officers, 5 with national officers, and 3 with UNICEF officials) and 36 focus group discussions (6 with men, 6 with women, 12 with adolescent boys, and 12 with service providers). Some of the men and women were parents of the adolescents who participated in the focus group discussions. In the French-speaking areas, the focus group discussions were conducted in French through an accredited translator, audio recorded, and transcribed into English. Results: All of the facilities we visited in Cameroon and Senegal offer medical male circumcision, with 10 out of 12 performing early infant male circumcision (EIMC) routinely. Neither country has policies, guidelines, or strategies for EIMC. The procedure is done mainly by untrained service providers, with some providers using modern circumcision devices. There are no key messages on EIMC for families; the increasing demand for EIMC is led by the community. Conclusion: Despite the absence of national policies and strategies, EIMC is routinely offered at all levels of the health care system in Cameroon and Senegal, mainly by untrained service providers. Improving circumcision services will require guidelines for EIMC and improvements in training, equipment, supply chains, recordkeeping, and demand creation. PMID:27413080

  12. Geochemical Characteristics and Metallogenesis of Volcanic Rocks as Exemplified by Volcanic Rocks in Ertix,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    刘铁庚; 叶霖

    1997-01-01

    Volcanic rocks in Ertix,Xinjiang,occurring in the collision zone between the Siberia Plate and the Junggar Plate,are distributed along the Eritix River Valley in northern Xinjiang.The volcanic rocks were dated at Late Paleozoic and can be divided into the spilite-keratophyre series and the basalt-andesite series.The spilite-keratophyre series volcanic rocks occur in the Altay orogenic belt at the southwest margin of the Siberia Plate.In addition to sodic volcanic rocks.There are also associated potassic-sodic volcanic rocks and potassic volcanic rocks.The potassic-sodic volcanic rocks occur at the bottom of the eruption cycle and control the distribution of Pb and Zn deposits.The potassic volcanic rocks occur at the top of the eruption cycle and are associated with Au and Cu mineralizations.The sodic volcanic rocks occur in the middle stage of eruption cycle and control the occurrence of Cu(Zn) deposits.The basalt-andesite series volcanic rocks distributed in the North Junggar orogenic belt at the north margin of the Junggar-Kazakstan Plate belong to the potassic sodic volcain rocks.The volcanic rocks distributed along the Ulungur fault are relatively rich in sodium and poor in potassium and are predominated by Cu mineralization and associated with Au mineralization.Those volcanic rocks distributed along the Ertix fault are relatively rich in K and poor in Na,with Au mineralization being dominant.

  13. [Hygiene and microbiologic quality of ice creams produced in Cameroon. A public health problem].

    Science.gov (United States)

    Wouafo, M N; Njine, T; Tailliez, R

    1996-01-01

    Three hundred samples of ice cream produced in two main towns in Cameroon (Douala and Yaoundé) are evaluated for their hygienic quality. The microbiologic examinations show that many of them are contaminated with bacteria of faecal origin, pathogenic Staphylococcus and Salmonella respectively in 71.3, 49.6 and 5% of the products examinations in the study. The use of non potable water and the disrespect of the hygienic rules during the production are the main causes of contamination. Recommendations are made to preserve the public health in the developing country. PMID:9264738

  14. Neotectonic earth movements related to the 1999 eruption of Cameroon Mountain, West Africa

    Institute of Scientific and Technical Information of China (English)

    C. E. Suh; S. N. Ayonghe; E. S. Njumbe

    2001-01-01

    @@ The 1999 eruption of Cameroon Mountain was restricted to two sites and controlled by fissures subparallel to one another. Brittle failure, vertical displacement, horizontal displacement and ground deflation are the main types of ground deformation around these sites. The eruptive vents at both sites have a NE-SW trend parallel to the principal eruptive fissures and brittle discontinuities in rock bodies in this vicinity. SH (greatest horizontal stress) is inferred to have a SW-NE trend parallel to the direction of vent migration and fracture propagation.

  15. Cameroon National Report on Code of Conduct on Safety and Security of Radioactive Sources

    International Nuclear Information System (INIS)

    Triggered by the expansion of national economic and social sectors, the demand for nuclear science and technology applications in Cameroon is marking an ever growing trend in scale and scope. Consequently, there is an increasing use of radioactive sources in various socio-economic developmental activities and the above development calls for organized and coherent measures to regulate and control the applications of radioactive sources from a safety and security perspective without impeding on the beneficial application thereof. As of April 2013, 156 radioactive sources have been identified to be extensively in used for beneficial purposes in Cameroon in medical, industrial, agricultural, research and educational applications. Ensuring their safety and security has been done for the past three years by National Radiation Protection Agency (NRPA) and significant improvements have been made in this respect. However, proper legislative framework and adequate resources remain major concerns. Many efforts are being put in place to review the current situation and to identify the means of maintaining the highest possible level of safety and security of radioactive sources throughout their lifecycle and everywhere in Cameroon. The primary foundations through which valuable regulatory exercise could be ensured is by developing and sustaining sound national regulatory infrastructures which is equipped to effectively and efficiently implement regulatory control over the application of nuclear technology and practices involving the use of radiation sources at a national level and by promoting regional cooperation among Regulatory Bodies. In the context of the above development, NRPA has been part of the Forum of Nuclear Regulatory Bodies in Africa (FNRBA) since 2009 and the AFRA Projects on Self-Assessment of Regulatory Infrastructure for Safety and Networking of Regulatory Bodies (RAF 9038) and Sustaining the Regulatory Infrastructure for the Control of Radiation Sources (RAF

  16. THE ECONOMIC IMPACT OF CORRUPTION IN AFRICA AND THE WAY FORWARD : Case study: Cameroon

    OpenAIRE

    Njomen, Pride; Njomen, Pride Nkwinja

    2016-01-01

    This thesis is based on a holistic approach to analysing corruption and its economic impact in Africa, using Cameroon as a case study. It seek to analyse precolonial Africa and how their justice system led to low corruption and the slave trade how slavery contributed to today’s corruption the colonial rule how the divide and rule policies, imposed taxes etc., led to deaths, especially in the Congo, suppression of civil rights, exploitation and misery up to the 1960s, obstruction of natural...

  17. Cameroon mid-level providers offer a promising public health dentistry model

    Directory of Open Access Journals (Sweden)

    Achembong Leo

    2012-11-01

    Full Text Available Background Oral health services are inadequate and unevenly distributed in many developing countries, particularly those in sub-Saharan Africa. Rural areas in these countries and poorer sections of the population in urban areas often do not have access to oral health services mainly because of a significant shortage of dentists and the high costs of care. We reviewed Cameroon’s experience with deploying a mid-level cadre of oral health professionals and the feasibility of establishing a more formal and predictable role for these health workers. We anticipate that a task-shifting approach in the provision of dental care will significantly improve the uneven distribution of oral health services particularly in the rural areas of Cameroon, which is currently served by only 3% of the total number of dentists. Methods The setting of this study was the Cameroon Baptist Convention Health Board (BCHB, which has four dentists and 42 mid-level providers. De-identified data were collected manually from the registries of 10 Baptist Convention clinics located in six of Cameroon’s 10 regions and then entered into an Excel format before importing into STATA. A retrospective abstraction of all entries for patient visits starting October 2010, and going back in time until 1500 visits were extracted from each clinic. Results This study showed that mid-level providers in BCHB clinics are offering a full scope of dental work across the 10 clinics, with the exception of treatment for major facial injuries. Mid-level providers alone performed 93.5% of all extractions, 87.5% of all fillings, 96.5% of all root canals, 97.5% of all cleanings, and 98.1% of all dentures. The dentists also typically played a teaching role in training the mid-level providers. Conclusions The Ministry of Health in Cameroon has an opportunity to learn from the BCHB model to expand access to oral health care across the country. This study shows the benefits of using a simple, workable, low

  18. Still on the Tracks of the Congo Clawless Otter (Aonyx congicus: First Mission in Cameroon

    Directory of Open Access Journals (Sweden)

    Alary F.

    2002-04-01

    Full Text Available 15 day first-step mission was undertaken in Cameroon during February 2002. The purpose of this prospective trip was, first of all, to raise interest amongst wildlife institutions (Governmental and NGOs concerning the 3 species of otters supposed to inhabit this country. The same kind of work has been initiated in Western African countries such as Togo, Burkina-Faso, Benin and Niger. This will allow the institution of a network around the French speaking part of Africa, in order to collect information on distribution, status and threats as regards otters.

  19. [Commercial sexual exploitation of minor girls. A multifocal, exploratory and prospective study in Cameroon].

    Science.gov (United States)

    Mbassa Menick, D; Dassa, K S; Kenmogne, J B; Abanda Ngon, G

    2009-02-01

    To obtain reliable information on commercial sexual exploitation of minor girls under the age of 21, a multifocal, exploratry and prospective using a questionnaire was undertaken in Cameroon. This investigation was initiated and funded by the Cercle International pour la Promotion de la Création (CIPCRE) and carried out by the Cameroon Society for the Prevention of Child Abuse and Neglect (CASPCAN). The survey was performed during the last quarter of year 2004 in four major cities of Cameroon, i.e. Yaoundé, Douala, Bamenca and Bafoussam. Of the 800 questionnaires that were distributed, 722 were considered as suitable for analysis (90.3%). A total of 291 minor girls were victims of commercial sexual exploitation, i.e., 40% of the population studied. The mean age of the victims was 16.6 years (range, 9-20 years). The main reason given for entering prostitution was poverty. The victims were fairly well educated but the level of instruction was not sufficient to find a job paying an income comparable to prostitution. Many were from large families (mean, 7.1 children). The victims' family was monogamous in 40.2% of cases, polygamous in 24.4%, and monoparental in 35.4%. Eighty percent of the victims already had run away from home at least once due to problems in their families ranging from severe corporal punishment (25.8%) and mistreatment linked to parental alcohol and drug abuse to forced early marriage (27.5%) and intrafamilial sexual abuse. A large proportion of the victims (36.4%) were mothers who could not attend school and could not find work. Many victims were completely neglected by their own parents with 43.4% of parents being aware of the activities of their daughters but only 10.6% being opposed to it. Most (78.5%) had good knowledge of the risk of HIV and used condoms regular. These results confirms the general hypothesis of the authors that commercial exploitation of minor girls is widespread in Cameroon. The authors recommend development of a national

  20. A practical approach to low protein diets for patients with chronic kidney disease in Cameroon.

    Science.gov (United States)

    Ashuntantang, Gloria Enow; Fouda, Hermine; Kaze, Francois Folefack; Halle, Marie-Patrice; Tabi-Arrey, Crista; Biwole-Sida, Magloire

    2016-01-01

    Cameroon is a low-middle income country with a rich diversity of culture and cuisine. Chronic kidney disease (CKD) is common in Cameroon and over 80 % of patients present late for care, precluding the use of therapies such as low protein diets (LPDs) that slow its progression. Moreover, the prescription of LPDs is challenging in Cameroon because dieticians are scarce, there are no renal dieticians, and people often have to fund their own healthcare. The few nephrologists that provide care for CKD patients have limited expertise in LPD design. Therefore, only moderate LPDs of 0.6 g protein per kg bodyweight per day, or relatively mild LPDs of 0.7-0.8 g protein per kg bodyweight per day are prescribed. The moderate LPD is prescribed to patients with stage 3 or 4 CKD with non-nephrotic proteinuria, no evidence of malnutrition and no interrcurrent acute illnesses. The mild LPD is prescribed to patients with stage 3 or 4 CKD with nephrotic proteinuria, non-symptomatic stage 5 CKD patients or stage 5 CKD patients on non-dialysis treatment. In the absence of local sources of amino and keto acid supplements, traditional mixed LPDs are used. For patients with limited and sporadic access to animal proteins, the prescribed LPDs do not restrict vegetable proteins, but limit intake of animal proteins (when available) to 70 % of total daily protein intake. For those with better access to animal proteins, the prescribed LPDs limit intake of animal proteins to 50-70 % of total daily protein intake, depending on their meal plan. Images of 100 g portions of meat, fish and readily available composite meals serve as visual guides of quantities for patients. Nutritional status is assessed before LPD prescription and during follow up using a subjective global assessment and serum albumin. In conclusion, LPDs are underutilised and challenging to prescribe in Cameroon because of weakness in the health system, the rarity of dieticians, a wide diversity of dietary habits, the limited

  1. Volcanic Rocks As Targets For Astrobiology Missions

    Science.gov (United States)

    Banerjee, N.

    2010-12-01

    Almost two decades of study highlight the importance of terrestrial subaqueous volcanic rocks as microbial habitats, particularly in glass produced by the quenching of basaltic lava upon contact with water. On Earth, microbes rapidly begin colonizing glassy surfaces along fractures and cracks exposed to water. Microbial colonization of basaltic glass leads to enhanced alteration through production of characteristic granular and/or tubular bioalteration textures. Infilling of formerly hollow alteration textures by minerals enable their preservation through geologic time. Basaltic rocks are a major component of the Martian crust and are widespread on other solar system bodies. A variety of lines of evidence strongly suggest the long-term existence of abundant liquid water on ancient Mars. Recent orbiter, lander and rover missions have found evidence for the presence of transient liquid water on Mars, perhaps persisting to the present day. Many other solar system bodies, notably Europa, Enceladus and other icy satellites, may contain (or have once hosted) subaqueous basaltic glasses. The record of terrestrial glass bioalteration has been interpreted to extend back ~3.5 billion years and is widespread in modern oceanic crust and its ancient metamorphic equivalents. The terrestrial record of glass bioalteration strongly suggests that glassy or formerly glassy basaltic rocks on extraterrestrial bodies that have interacted with liquid water are high-value targets for astrobiological exploration.

  2. Small global-mean cooling due to volcanic radiative forcing

    Science.gov (United States)

    Gregory, J. M.; Andrews, T.; Good, P.; Mauritsen, T.; Forster, P. M.

    2016-03-01

    In both the observational record and atmosphere-ocean general circulation model (AOGCM) simulations of the last ˜ 150 years, short-lived negative radiative forcing due to volcanic aerosol, following explosive eruptions, causes sudden global-mean cooling of up to ˜ 0.3 K. This is about five times smaller than expected from the transient climate response parameter (TCRP, K of global-mean surface air temperature change per W m-2 of radiative forcing increase) evaluated under atmospheric CO2 concentration increasing at 1 % yr-1. Using the step model (Good et al. in Geophys Res Lett 38:L01703, 2011. doi: 10.1029/2010GL045208), we confirm the previous finding (Held et al. in J Clim 23:2418-2427, 2010. doi: 10.1175/2009JCLI3466.1) that the main reason for the discrepancy is the damping of the response to short-lived forcing by the thermal inertia of the upper ocean. Although the step model includes this effect, it still overestimates the volcanic cooling simulated by AOGCMs by about 60 %. We show that this remaining discrepancy can be explained by the magnitude of the volcanic forcing, which may be smaller in AOGCMs (by 30 % for the HadCM3 AOGCM) than in off-line calculations that do not account for rapid cloud adjustment, and the climate sensitivity parameter, which may be smaller than for increasing CO2 (40 % smaller than for 4 × CO2 in HadCM3).

  3. Alkaline volcanic rocks from the Columbia Hills, Gusev crater, Mars

    Science.gov (United States)

    McSween, H.Y.; Ruff, S.W.; Morris, R.V.; Bell, J.F., III; Herkenhoff, K.; Gellert, Ralf; Stockstill, K.R.; Tornabene, L.L.; Squyres, S. W.; Crisp, J.A.; Christensen, P.R.; McCoy, T.J.; Mittlefehldt, D. W.; Schmidt, M.

    2006-01-01

    Irvine, Backstay, and Wishstone are the type specimens for three classes of fine-grained or fragmental, relatively unaltered rocks with distinctive thermal emission spectra, found as float on the flanks of the Columbia Hills. Chemical analyses indicate that these rocks are mildly alkaline basalt, trachybasalt, and tephrite, respectively. Their mineralogy consists of Na- and K-rich feldspar(s), low- and high-Ca pyroxenes, ferroan olivine, Fe-Ti (and possibly Cr) oxides, phosphate, and possibly glass. The texture of Wishstone is consistent with a pyroclastic origin, whereas Irvine and Backstay are lavas or possibly dike rocks. Chemical compositions of these rocks plot on or near liquid lines of descent for most elements calculated for Adirondack class rocks (olivine-rich basalts from the Gusev plains) at various pressures from 0.1 to 1.0 GPa. We infer that Wishstone-, Backstay-, and Irvine-class magmas may have formed by fractionation of primitive, oxidized basaltic magma similar to Adirondack-class rocks. The compositions of all these rocks reveal that the Gusev magmatic province is alkaline, distinct from the subalkaline volcanic rocks thought to dominate most of the planet's surface. The fact that differentiated volcanic rocks were not encountered on the plains prior to ascending Husband Hill may suggest a local magma source for volcanism beneath Gusev crater. Copyright 2006 by the American Geophysical Union.

  4. Engineering a robotic approach to mapping exposed volcanic fissures

    Science.gov (United States)

    Parcheta, C. E.; Parness, A.; Mitchell, K. L.

    2014-12-01

    Field geology provides a framework for advanced computer models and theoretical calculations of volcanic systems. Some field terrains, though, are poorly preserved or accessible, making documentation, quantification, and investigation impossible. Over 200 volcanologists at the 2012 Kona Chapman Conference on volcanology agreed that and important step forward in the field over the next 100 years should address the realistic size and shape of volcanic conduits. The 1969 Mauna Ulu eruption of Kīlauea provides a unique opportunity to document volcanic fissure conduits, thus, we have an ideal location to begin addressing this topic and provide data on these geometries. Exposed fissures can be mapped with robotics using machine vision. In order to test the hypothesis that fissures have irregularities with depth that will influence their fluid dynamical behavior, we must first map the fissure vents and shallow conduit to deci- or centimeter scale. We have designed, constructed, and field-tested the first version of a robotic device that will image an exposed volcanic fissure in three dimensions. The design phase included three steps: 1) create the payload harness and protective shell to prevent damage to the electronics and robot, 2) construct a circuit board to have the electronics communicate with a surface-based computer, and 3) prototype wheel shapes that can handle a variety of volcanic rock textures. The robot's mechanical parts were built using 3d printing, milling, casting and laser cutting techniques, and the electronics were assembled from off the shelf components. The testing phase took place at Mauna Ulu, Kīlauea, Hawai'i, from May 5 - 9, 2014. Many valuable design lessons were learned during the week, and the first ever 3D map from inside a volcanic fissure were successfully collected. Three vents had between 25% and 95% of their internal surfaces imaged. A fourth location, a non-eruptive crack (possibly a fault line) had two transects imaging the textures

  5. Cenozoic volcanic rocks of Saudi Arabia

    Science.gov (United States)

    Coleman, R.G.; Gregory, R.T.; Brown, G.F.

    2016-01-01

    The Cenozoic volcanic rocks of Saudi Arabia cover about 90,000 km2, one of the largest areas of alkali olivine basalt in the world. These volcanic rocks are in 13 separate fields near the eastern coast of the Red Sea and in the western Arabian Peninsula highlands from Syria southward to the Yemen Arab Republic.

  6. Relationship between earthquake and volcanic eruption inferred from historical records

    Institute of Scientific and Technical Information of China (English)

    陈洪洲; 高峰; 吴雪娟; 孟宪森

    2004-01-01

    A large number of seismic records are discovered for the first time in the historical materials about Wudalianchi volcanic group eruption in 1720~1721, which provides us with abundant volcanic earthquake information. Based on the written records, the relationship between earthquake and volcanic eruption is discussed in the paper. Furthermore it is pointed that earthquake swarm is an important indication of volcanic eruption. Therefore, monitoring volcanic earthquakes is of great significance for forecasting volcanic eruption.

  7. Common challenges in gum arabic production and commercialization in West Africa: a comparative study of Cameroon, Niger and Senegal

    NARCIS (Netherlands)

    Mujawamariya, G.; Madi, O.P.; Zoubeirou, A.M.; Sene, A.; Maisharou, A.; Haese, D' M.F.C.

    2013-01-01

    As gum arabic is widely used in food and non-food industries, demand is high all over the world. Still, smaller production countries in West Africa such as Cameroon, Niger and Senegal seem to have so many difficulties producing and commercializing gum arabic that their market shares have declined si

  8. SMALL Savannah : an information system for the integrated analysis of land use change in the Far North of Cameroon

    NARCIS (Netherlands)

    Fotsing, Eric

    2009-01-01

    SMALL Savannah is an Environmental Information System designed for the integrated analysis and sustainable land management in the savannas region of the Far North of Cameroon. This system combines an observation and spatial analysis module for the representation of phenomena from various geographic

  9. Molecular Epidemiology of HIV Type 1 CRF02_AG in Cameroon and African Patients Living in Italy

    Science.gov (United States)

    Véras, Nazle Mendonca Collaço; Santoro, Maria Mercedes; Gray, Rebecca R.; Tatem, Andrew J.; Presti, Alessandra Lo; Olearo, Flaminia; Cappelli, Giulia; Colizzi, Vittorio; Takou, Desiré; Torimiro, Judith; Russo, Gianluca; Callegaro, Annapaola; Salpini, Romina; D'Arrigo, Roberta; Perno, Carlo-Federico; Goodenow, Maureen M.; Ciccozzi, Massimo

    2011-01-01

    Abstract HIV-1 CRF02_AG accounts for >50% of infected individuals in Cameroon. CRF02_AG prevalence has been increasing both in Africa and Europe, particularly in Italy because of migrations from the sub-Saharan region. This study investigated the molecular epidemiology of CRF02_AG in Cameroon by employing Bayesian phylodynamics and analyzed the relationship between HIV-1 CRF02_AG isolates circulating in Italy and those prevalent in Africa to understand the link between the two epidemics. Among 291 Cameroonian reverse transcriptase sequences analyzed, about 70% clustered within three distinct clades, two of which shared a most recent common ancestor, all related to sequences from Western Africa. The major Cameroonian clades emerged during the mid-1970s and slowly spread during the next 30 years. Little or no geographic structure was detected within these clades. One of the major driving forces of the epidemic was likely the high accessibility between locations in Southern Cameroon contributing to the mobility of the population. The remaining Cameroonian sequences and the new strains isolated from Italian patients were interspersed mainly within West and Central African sequences in the tree, indicating a continuous exchange of CRF02_AG viral strains between Cameroon and other African countries, as well as multiple independent introductions in the Italian population. The evaluation of the spread of CRF02_AG may provide significant insight about the future dynamics of the Italian and European epidemic. PMID:21453131

  10. The determinants of the willingness-to-pay for community-based prepayment scheme in rural Cameroon.

    Science.gov (United States)

    Donfouet, Hermann Pythagore Pierre; Makaudze, Ephias; Mahieu, Pierre-Alexandre; Malin, Eric

    2011-09-01

    In rural Cameroon, many people have no access to quality healthcare services. This is largely attributed to lack of private out-of-pocket payment to finance healthcare services. A community-based prepayment health insurance scheme may be implemented to improve healthcare access in rural areas. This study examines the determinants of willingness-to-pay for a community-based prepayment healthcare system using a contingent valuation method conducted in rural Cameroon. To mitigate potential hypothetical bias, a consequential script is introduced in the questionnaire. The results indicate age, religion, profession, knowledge of community-based health insurance, awareness of usual practice in rural areas, involvement in association and disposable income are the key determinants of willingness to pay for a prepayment health scheme. On average, willingness to pay for the scheme by rural households is 1011 CFA francs/person/month (2.15 US dollars). The results underlie two important implications: first, there is substantial demand for a community healthcare prepayment scheme by rural poor households in Cameroon; second, rural households are averse to health shocks and hence they are willing to sacrifice monthly premium payments to protect themselves (and their households) from unforeseen health-related risks. If government could engage in social marketing strategies such as mass media campaigns and awareness, this could prove vital for encouraging participation by the rural poor in healthcare prepayment scheme in Cameroon. PMID:21874541

  11. Diversity patterns in the flora of the Campo-Ma'an rain forest, Cameroon: do tree species tell it all?

    NARCIS (Netherlands)

    Tchouto, M.G.P.; Boer, de W.F.; Wilde, de J.J.F.E.; Maesen, van der L.J.G.

    2006-01-01

    This study describes diversity patterns in the flora of the Campo-Ma¿an rain forest, in south Cameroon. In this area, the structure and composition of the forests change progressively from the coastal forest on sandy shorelines through the lowland evergreen forest rich in Caesalpinioideae with Calpo

  12. ''I Eat to Be Happy, to Be Strong, and to Live.'' Perceptions of Rural and Urban Adolescents in Cameroon, Africa

    Science.gov (United States)

    Dapi, Leonie N.; Omoloko, Cecile; Janlert, Urban; Dahlgren, Lars; Haglin, Lena

    2007-01-01

    Objective: To investigate factors influencing rural and urban adolescents' food perceptions during a time of nutritional transition in Cameroon, Africa. Design: Qualitative in-depth interviews. Settings: Yaounde urban and Bandja rural areas. Participants: Fifteen adolescents 12 to 15 years old purposely selected from schools in urban and rural…

  13. English-Medium Instruction in an English-French Bilingual Setting: Issues of Quality and Equity in Cameroon

    Science.gov (United States)

    Kuchah, Kuchah

    2016-01-01

    Despite its multilingual nature Cameroon's educational system provides for full immersion into either French-medium or English-medium education from the first year schooling. Following political tensions in the early 1990s the country decided to reaffirm its commitment to promote bilingualism in the educational system with the outcome being the…

  14. An Exploration of the Relationship between Language Attitudes and Ideologies in a Study of Francophone Students of English in Cameroon

    Science.gov (United States)

    Dyers, Charlyn; Abongdia, Jane-Francis

    2010-01-01

    What are the similarities and differences between the concepts "language attitudes" (LAs) and "language ideologies" (LIs)? The need to answer this question arose from a study done by Abongdia in Cameroon with Francophone high school students of English to determine their attitudes towards English as well as their motivation for learning the…

  15. Women Farmers' Perceptions of the Economic Problems Influencing Their Productivity in Agricultural Systems: Meme Division of the Southwest Province, Cameroon.

    Science.gov (United States)

    Endeley, Joyce B.

    Women farmers produce about 60% of the food in Cameroon, but face more problems and constraints than men in performing their agricultural activities. Cash crop farmers (mostly men) are the targeted beneficiaries of government and international aids, and have better access to extension services, loans, subsidized production input (herbicides,…

  16. Age and petrology of the Usun Apau and Linau Balui volcanics : windows to central Borneo’s interior.

    OpenAIRE

    Cullena, A.; Macpherson, C.; Taib, N. I.; Burton-Johnson, A.; Dennis Geist, D.; Spell, T.; Banda, R.M.

    2013-01-01

    The Usun Apau plateau lies in a remote area of Sarawak along the Tinjar Line, which defines the onshore part of a suture between the Luconia and Dangerous Grounds blocks. Reconnaissance studies in late 1950s established that the plateau is composed of a bimodal suite of young volcanic rocks, but no further work exists to constrain the age and petrogenesis of the Usun Apau volcanics. We present and discuss new data from a suite of volcanic rocks recently collected from the Usun Apau region. Th...

  17. Assessing volcanic hazards with Vhub

    Science.gov (United States)

    Palma, J. L.; Charbonnier, S.; Courtland, L.; Valentine, G.; Connor, C.; Connor, L.

    2012-04-01

    Vhub (online at vhub.org) is a virtual organization and community cyberinfrastructure designed for collaboration in volcanology research, education, and outreach. One of the core objectives of this project is to accelerate the transfer of research tools to organizations and stakeholders charged with volcano hazard and risk mitigation (such as volcano observatories). Vhub offers a clearinghouse for computational models of volcanic processes and data analysis, documentation of those models, and capabilities for online collaborative groups focused on issues such as code development, configuration management, benchmarking, and validation. Vhub supports computer simulations and numerical modeling at two levels: (1) some models can be executed online via Vhub, without needing to download code and compile on the user's local machine; (2) other models are not available for online execution but for offline use in the user's computer. VHub also has wikis, blogs and group functions around specific topics to encourage collaboration, communication and discussion. Some of the simulation tools currently available to Vhub users are: Energy Cone (rapid delineation of the impact zone by pyroclastic density currents), Tephra2 (tephra dispersion forecast tool), Bent (atmospheric plume analysis), Hazmap (simulate sedimentation of volcanic particles) and TITAN2D (mass flow simulation tool). The list of online simulations available on Vhub is expected to expand considerably as the volcanological community becomes more involved in the project. This presentation focuses on the implementation of online simulation tools, and other Vhub's features, for assessing volcanic hazards following approaches similar to those reported in the literature. Attention is drawn to the minimum computational resources needed by the user to carry out such analyses, and to the tools and media provided to facilitate the effective use of Vhub's infrastructure for hazard and risk assessment. Currently the project

  18. Geosphere-biosphere interactions in bio-activity volcanic lakes: evidences from Hule and Rio Cuarto (Costa Rica.

    Directory of Open Access Journals (Sweden)

    Jacopo Cabassi

    Full Text Available Hule and Río Cuarto are maar lakes located 11 and 18 km N of Poás volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemical processes occur in these meromictic lakes. Although the two lakes host different bacterial and archaeal phylogenetic groups, water and gas chemistry in both lakes is controlled by the same prokaryotic functions, especially regarding the CO2-CH4 cycle. Addition of hydrothermal CO2 through the bottom of the lakes plays a fundamental priming role in developing a stable water stratification and fuelling anoxic bacterial and archaeal populations. Methanogens and methane oxidizers as well as autotrophic and heterotrophic aerobic bacteria responsible of organic carbon recycling resulted to be stratified with depth and strictly related to the chemical-physical conditions and availability of free oxygen, affecting both the CO2 and CH4 chemical concentrations and their isotopic compositions along the water column. Hule and Río Cuarto lakes were demonstrated to contain a CO2 (CH4, N2-rich gas reservoir mainly controlled by the interactions occurring between geosphere and biosphere. Thus, we introduced the term of bio-activity volcanic lakes to distinguish these lakes, which have analogues worldwide (e.g. Kivu: D.R.C.-Rwanda; Albano, Monticchio and Averno: Italy; Pavin: France from volcanic lakes only characterized by geogenic CO2 reservoir such as Nyos and Monoun

  19. Geosphere-biosphere interactions in bio-activity volcanic lakes: evidences from Hule and Rìo Cuarto (Costa Rica).

    Science.gov (United States)

    Cabassi, Jacopo; Tassi, Franco; Mapelli, Francesca; Borin, Sara; Calabrese, Sergio; Rouwet, Dmitri; Chiodini, Giovanni; Marasco, Ramona; Chouaia, Bessem; Avino, Rosario; Vaselli, Orlando; Pecoraino, Giovannella; Capecchiacci, Francesco; Bicocchi, Gabriele; Caliro, Stefano; Ramirez, Carlos; Mora-Amador, Raul

    2014-01-01

    Hule and Río Cuarto are maar lakes located 11 and 18 km N of Poás volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemical processes occur in these meromictic lakes. Although the two lakes host different bacterial and archaeal phylogenetic groups, water and gas chemistry in both lakes is controlled by the same prokaryotic functions, especially regarding the CO2-CH4 cycle. Addition of hydrothermal CO2 through the bottom of the lakes plays a fundamental priming role in developing a stable water stratification and fuelling anoxic bacterial and archaeal populations. Methanogens and methane oxidizers as well as autotrophic and heterotrophic aerobic bacteria responsible of organic carbon recycling resulted to be stratified with depth and strictly related to the chemical-physical conditions and availability of free oxygen, affecting both the CO2 and CH4 chemical concentrations and their isotopic compositions along the water column. Hule and Río Cuarto lakes were demonstrated to contain a CO2 (CH4, N2)-rich gas reservoir mainly controlled by the interactions occurring between geosphere and biosphere. Thus, we introduced the term of bio-activity volcanic lakes to distinguish these lakes, which have analogues worldwide (e.g. Kivu: D.R.C.-Rwanda; Albano, Monticchio and Averno: Italy; Pavin: France) from volcanic lakes only characterized by geogenic CO2 reservoir such as Nyos and Monoun (Cameroon).

  20. Geosphere-Biosphere Interactions in Bio-Activity Volcanic Lakes: Evidences from Hule and Rìo Cuarto (Costa Rica)

    Science.gov (United States)

    Cabassi, Jacopo; Tassi, Franco; Mapelli, Francesca; Borin, Sara; Calabrese, Sergio; Rouwet, Dmitri; Chiodini, Giovanni; Marasco, Ramona; Chouaia, Bessem; Avino, Rosario; Vaselli, Orlando; Pecoraino, Giovannella; Capecchiacci, Francesco; Bicocchi, Gabriele; Caliro, Stefano; Ramirez, Carlos; Mora-Amador, Raul

    2014-01-01

    Hule and Río Cuarto are maar lakes located 11 and 18 km N of Poás volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemical processes occur in these meromictic lakes. Although the two lakes host different bacterial and archaeal phylogenetic groups, water and gas chemistry in both lakes is controlled by the same prokaryotic functions, especially regarding the CO2-CH4 cycle. Addition of hydrothermal CO2 through the bottom of the lakes plays a fundamental priming role in developing a stable water stratification and fuelling anoxic bacterial and archaeal populations. Methanogens and methane oxidizers as well as autotrophic and heterotrophic aerobic bacteria responsible of organic carbon recycling resulted to be stratified with depth and strictly related to the chemical-physical conditions and availability of free oxygen, affecting both the CO2 and CH4 chemical concentrations and their isotopic compositions along the water column. Hule and Río Cuarto lakes were demonstrated to contain a CO2 (CH4, N2)-rich gas reservoir mainly controlled by the interactions occurring between geosphere and biosphere. Thus, we introduced the term of bio-activity volcanic lakes to distinguish these lakes, which have analogues worldwide (e.g. Kivu: D.R.C.-Rwanda; Albano, Monticchio and Averno: Italy; Pavin: France) from volcanic lakes only characterized by geogenic CO2 reservoir such as Nyos and Monoun (Cameroon). PMID

  1. Ethnomedicinal Plants Used by Traditional Healers to Treat Oral Health Problems in Cameroon

    Directory of Open Access Journals (Sweden)

    Michael Ashu Agbor

    2015-01-01

    Full Text Available Objectives. The objective of the study was to determine the therapeutic methods used by traditional healers to treat oral diseases in Cameroon. Methods. A total of 200 traditional healers with a mean age of 50.4±14.2 years from all the provinces of Cameroon were studied using questionnaires. Information elicited was the local names of the medicinal plants used for the management of oral problems, their routes of administration, and methods of usage. Identification of live or dried plants or photographs of sample of the plants was done by a taxonomist. Results. The majority of the participants were males urban dwellers aged 41–50 years, 112 (56.0% practice as herbalists and 56 (28.0% were trained on medications preservation, 77(56.6% treat diseases inside or outside the mouth, and 9.0% reported being specialist in oral diseases treatment. Of the 52 plants identified, 48 are used in the management of toothache, sore throat, mouth sores, abscess, broken tooth and jaw, tooth sensitivity, mouth thrush, dental caries, gingivitis, sinusitis, tonsillitis, xerostomia, oral syphilis, oral cancer, TMJ pain, halitosis, and tooth bleaching and 4 plants are used for dental extraction. Roots, leaves, and bark were the parts of plants used and some minerals as adjuncts. Conclusion. The study provides comprehensive information on therapeutic methods employed by traditional healers for the treatment of oral diseases.

  2. Ethnomedicinal Plants Used by Traditional Healers to Treat Oral Health Problems in Cameroon.

    Science.gov (United States)

    Ashu Agbor, Michael; Naidoo, Sudeshni

    2015-01-01

    Objectives. The objective of the study was to determine the therapeutic methods used by traditional healers to treat oral diseases in Cameroon. Methods. A total of 200 traditional healers with a mean age of 50.4 ± 14.2 years from all the provinces of Cameroon were studied using questionnaires. Information elicited was the local names of the medicinal plants used for the management of oral problems, their routes of administration, and methods of usage. Identification of live or dried plants or photographs of sample of the plants was done by a taxonomist. Results. The majority of the participants were males urban dwellers aged 41-50 years, 112 (56.0%) practice as herbalists and 56 (28.0%) were trained on medications preservation, 77(56.6%) treat diseases inside or outside the mouth, and 9.0% reported being specialist in oral diseases treatment. Of the 52 plants identified, 48 are used in the management of toothache, sore throat, mouth sores, abscess, broken tooth and jaw, tooth sensitivity, mouth thrush, dental caries, gingivitis, sinusitis, tonsillitis, xerostomia, oral syphilis, oral cancer, TMJ pain, halitosis, and tooth bleaching and 4 plants are used for dental extraction. Roots, leaves, and bark were the parts of plants used and some minerals as adjuncts. Conclusion. The study provides comprehensive information on therapeutic methods employed by traditional healers for the treatment of oral diseases. PMID:26495020

  3. An Examination of Forest Certification Status among Logging Companies in Cameroon.

    Science.gov (United States)

    Nukpezah, Daniel; Alemagi, Dieudonne; Duguma, Lalisa; Minang, Peter; Mbosso, Charlie; Tchoundjeu, Zac

    2014-01-01

    This paper assesses the level of interest, awareness, and adoption of ISO 14001 and Forest Stewardship Council (FSC) certification schemes among logging companies in Cameroon. Eleven logging companies located in Douala in the Littoral Region of Cameroon were assessed through a structured interview using an administered questionnaire which was mostly analyzed qualitatively thereafter. The findings indicated that none of the companies was certified for ISO 14001; however 63.64% of them were already FSC-certified. Four companies (36.36%) were neither FSC- nor ISO 14001 EMS-certified. Among the factors found to influence the adoption rate was the level of awareness about ISO 14001 and FSC certification schemes. The main drivers for pursuing FSC certification were easy penetration into international markets, tax holiday benefits, and enhancement of corporate image of the logging companies through corporate social responsibility fulfillments. Poor domestic market for certified products was found to be the major impediment to get certified. To make logging activities more environmentally friendly and socially acceptable, logging companies should be encouraged to get certified through the ISO 14001 EMS scheme which is almost nonexistent so far. This requires awareness creation about the scheme, encouraging domestic markets for certified products and creating policy incentives. PMID:27355041

  4. Analysis and Application of Intelligent Transportation Systems to Taxi System in Cameroon

    Institute of Scientific and Technical Information of China (English)

    Nzegge Chantale Ebude; Wang Mingyan

    2007-01-01

    Most traffic control systems available in major cities in Cameroon are still out dated,make use of theories and models which are very slow to implement,waste resources and their efficiency is very low.Thus the number of road accidents encountered on our major highways and inter urban traffic networks has been increasing despite the various efforts made by government and certain NGO to synthesize road users on certain aspects of traffic control and safety road use.Taxis are not left out in the whole show and most of the blame always falls on them.The need to use available Information and Communication Technology ICT to improve on the control of traffic in inter urban cities and major highways is imperative.ITS optimizes the use of resources,reduce pollution,contribute to environmental protection and increases the national economy.This paper starts by giving a brief situation of the transportation system in Cameroon,its drawbacks and proposes an optimized ITS based system.

  5. Geographic Distribution of Childbirth among Adolescents in Cameroon from 2003 to 2005

    Directory of Open Access Journals (Sweden)

    P. M. Tebeu

    2010-01-01

    Full Text Available Objective. To determine the frequency and the trend of adolescents (10–19 years in childbirth within a period of 3 years in referral maternity units in Cameroon. Method. Descriptive and retrospective study for a 3-year period (2003–2005 in referral maternity units headed by a qualified Obstetrician-Gynecologist. We analyzed the trend and geographic distribution of 8222 adolescent deliveries over 3 years. Epi Info 3.5 software was used for data analysis. Chi square test for trend was used to assess the contribution of adolescent deliveries over years. The trend was considered significant if P<.05. Results. During the period of the study, there was a total of 8387 deliveries. We excluded 165 women because of lack of information about age. We therefore included a total of 8222 adolescent deliveries. Overall, the contribution of adolescents to deliveries ranged from 6.87% to 26.51%, depending on the region with a national mean of 14.23%. Adolescents aged 16 or less contributed to 2.82% of deliveries while those aged from 17 to 19 contributed to 11.41%. The contribution of adolescents to deliveries decreased significantly over 3 years (P<.0001. Conclusion. The study underscores the importance of Public Health programs in strengthening maternity services for adolescents in Cameroon while taking into consideration geographic differences.

  6. Correlates of Tax Compliance of Small and Medium Size Businesses in Cameroon

    Directory of Open Access Journals (Sweden)

    Oludele Akinloye Akinboade

    2015-12-01

    Full Text Available Taxation provides a predictable and stable flow of revenue to finance development objectives. This is important in a country like Cameroon that has serious challenges with meeting its development objectives. Small and medium enterprises (SMEs are significant for economic growth in the country, contributing as much as about 22 percent of the gross domestic product. SMEs generate taxable incomes. They also collect employment and value added taxes on behalf of the government. Taxation, however, imposes high cost to small businesses. SMEs are less tax compliant in comparison to large businesses. SMEs are considered the ‘hard to tax group from the informal sector.’ As such, the literature suggests that only a fraction of their taxable incomes is reported to tax authorities. Against this background, factors that correlate with tax compliance of 575 small and medium size companies in Cameroon are discussed from a survey of companies in the manufacturing and wholesale sectors. High registration cost and time-consuming processes promote tax non-compliance. The perception that tax system is corrupt discourages registration and filing compliance. When there are too many compliance hurdles, the probability of filing compliance is reduced. However, a fair and static system encourages filing and registration compliance. A clear and consistent tax system promotes filing compliance. Authorities that understand their responsibilities and are willing to respond to enquiries during the registration process promote tax compliance in general.

  7. Adoption of the Tenera Hybrid of Oil Palm (Elaeis guineensis Jacquin. among Smallholder Farmers in Cameroon

    Directory of Open Access Journals (Sweden)

    Assoumou Mezui, MR.

    2013-01-01

    Full Text Available The adoption of the Tenera oil palm (Elaeis guineensis Jacq. type was studied by focusing on 208 family farmers in Cameroon. The "Average Treatment Effect" (ATE method was used. This method enables to estimate, by use of a Probit model, the effects created when a farmer is exposed to treatment (or intervention, which represents a source of improved oil palm planting material. According to the results, the estimated adoption rate for Tenera is highly significant (P< 0.05 for all the categories of producers, regardless of the supply source, which may be formal or informal. In addition, the main factors that significantly determine this adoption are: availability of arable land in forested areas and whether growers intend to increase the size of their plantations. However, the supply of pure planting material remains an important constraint because the other two types of oil palm (Dura and Pisifera which produce poor palm oil yields are still mistakenly planted on many family farms in Cameroon. Further studies will address this issue in the aim of identifying appropriate solutions.

  8. NUCLEAR DNA CONTENT ANALYSIS OF FOUR CULTIVATED SPECIES OF YAMS (DIOSCOREA SPP. FROM CAMEROON

    Directory of Open Access Journals (Sweden)

    Marie F. Sandrine

    2014-08-01

    Full Text Available Yam (Dioscorea spp. is an important food source in Africa, but diseases and storage pests hinder the African farmers to achieve high yields during the harvest. One important limitation to the genetic breeding of yam is the relatively unknown ploidy level variation within and among species.  The objective of this study was to determine the nuclear DNA content of 59 accessions representing four cultivated Dioscorea species collected from three regions of Cameroon (Adamawa, Centre and Southwest using flow cytometry with propidium iodide staining. Our findings suggested the variation of the genome size both within and among the yams species. Nuclear DNA content (mean 2C-value in studied yam collection ranging from 0.72 ± 0.013 pg in D. dumetorum to 2.801 ± 0.068 pg in D. cayenensis. The accessions could be divided into four different categories according to their, nuclear DNA content suggestive of four different ploidy levels. Ploidy variation was observed within all species with the exception of D. dumetorum that is likely diploid. This study contributes to a better understanding of the genome characteristics of yam species from Cameroon and may help to the genetic improvement of this important crop in the future.

  9. Producers’ motivation for collective action for kola production and marketing in Cameroon

    Directory of Open Access Journals (Sweden)

    Steven Franzel

    2012-04-01

    Full Text Available Collective action has been used as a strategy to improve the benefits of smallholder producers of kola nuts in Cameroon. Despite demonstrated benefits, not all producers are involved in the collective action. The presented study used a modified Technology Acceptance Model (TAM namely the Collective Action Behaviour model (CAB model to analyse kola producers’ motivation for collective action activities. Five hypotheses are formulated and tested using data obtained from 185 farmers who are involved in kola production and marketing in theWestern highlands of Cameroon. Results which were generated using Partial Least Squares (PLS approach for Structural Equation Modelling (SEM showed that farmers’ intrinsic motivators and ease of use influenced their behavioural intent to join a group marketing activities. The perceived usefulness that was mainly related to the economic benefits of group activities did not influence farmers’ behavioural intent. It is therefore concluded that extension messages and promotional activities targeting collective action need to emphasise the perceived ease of use of involvement and social benefits associated with group activities in order to increase farmers’ participation.

  10. Evaluation of new tools for malaria vector control in Cameroon: focus on long lasting insecticidal nets.

    Directory of Open Access Journals (Sweden)

    Josiane Etang

    Full Text Available BACKGROUND: From 2006 to 2011, biological activity of insecticides for Indoor Residual Spraying (IRS, conventional treatment of nets (CTNs or long lasting insecticidal nets (LLINs was evaluated before their approval in Cameroon. The objective of the study was to select the best tools for universal malaria vector control coverage. METHODOLOGY: Bioassays were performed using WHO cones and the Kisumu susceptible strain of Anopheles gambiae s.s.. Among tested products, residual activity and wash resistance of Alpha-cypermethrin LLINs (Interceptor and CTNs (Fendona were assessed during 5 months in the Ntougou neighborhood. PRINCIPAL FINDINGS: All the 14 tested products were found effective (95-100% knockdown and mortality rates, although a significant decrease of efficacy was seen with lambda-cyhalothrinWP IRS, alpha-cypermethrin CTNs and LLINs (p< 0.05. However, the efficacy of Interceptor nets did not decrease during the 5 months evaluation, even after 25 washes (0.07Cameroon.

  11. Access To Land And The System Of Land Ownership In Northern Cameroon

    Directory of Open Access Journals (Sweden)

    Paul AHIDJO

    2012-06-01

    Full Text Available Northern Cameroon is a vast geographical region made up of a population with diverse customs, religion and migration process. The entire population is made up of paleo-nigritics, neo-Sudanese and pastoral nomads who practice activities such as agriculture, livestock and fisheries. This ethnic heterogeneity, complex historical events and cultural diversity has made the customary systemof land tenure to vary both in their ancient aspects as well as contemporary manifestations. Therefore, based on verbal assertion and written data, this article examines the methods of land access as well as the traditional and modern land tenure system. For the population of Northern Cameroon and elsewhere, land represents a natural resource of prime importance. Access to land and its control constitutes a major economic challenge and it is equally a source ofdiverse conflicts. The system of land ownership has been influenced by external unforeseen events. From the pre-colonial period to the so called post colonial period, access to land and land ownership vary between the conservation of a traditional system which land owners are trying to preserve and the weight of modernity which has economic implications.

  12. Farmer's Perception and Adoption of New Aquaculture Technologies in the Western Highlands of Cameroon

    Directory of Open Access Journals (Sweden)

    Njankoua Wandji, D.

    2012-01-01

    Full Text Available Like other African countries, Cameroon is struggling to meet the food needs of its population. There are several possible solutions to this problem, such as the import of agricultural produce and increasing national production. In terms of fishery products (fish, shrimps, etc., it would not be easy to increase national production, due to the various constraints inherent in the sector and national industry, as well as low availability of farming areas. Fish farming is one of the solutions recommended as a sustainable method of producing an adequate supply of fish (farming fish in ponds. The main objective of this study is to highlight and analyse the socio-economic obstacles that are holding back the development of fish farming in the West Cameroon. Using the univariate dichotomous LOGIT model, this study has made it possible to identify the key determinants affecting the adoption of fish farming. The results indicate that its strong commercial orientation, coupled with the positive perception of its profitability, frequent contact, extension and level of education are the main determinants for the adoption of fish farming.

  13. Quantitative Effects of Early and Late Blights on Tomato Yields in Cameroon

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    Fontem, DA.

    2003-01-01

    Full Text Available Early blight caused by Alternaria solani and late blight caused by Phytophthora infestans are the major diseases of tomato (Lycopersicon esculentum in Cameroon. The effect of both diseases on fruit yield was evaluated during the 1995 growing season in Dschang, Cameroon.Ten varieties were planted in the first trial (March-July and nine in the second (July- November. In both trials, plots were sprayed weekly with Ridomil Plus (2.0 kg/ha before flowering and with maneb (1.6 kg/ha after flowering. Early blight was more severe in the early part of the first trial, while late blight caused most damage during the second. Marketable yields varied according to variety. High yields in sprayed plots were obtained in Dona F1 (61.63 t/ha and Heinz 1370 (68.24 t/ha during the first trial, and in Fline (58.35 t/ha, Mecline (64.25 t/ha, and Moboline (55.16 t/ha during the second trial. Percent fruit infection in sprayed plots caused by both diseases varied according to variety from 12 to 65% in the first season and from 14 to 52% in the second, while losses in marketable yields for both blights were as high as 100% in unsprayed plots.

  14. A Crispy Delicacy: Augosoma Beetle as Alternative Source of Protein in East Cameroon

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    F. J. Muafor

    2014-01-01

    Full Text Available Despite the fact that the exoskeleton of the Augosoma centaurus (Dynastinae is hard and difficult to chew, this insect is often gathered in Eastern Cameroon for food in periods of availability. Nine ethnic groups in Eastern Cameroon were surveyed to understand the role of this insect in assuring food security, using quantitative and qualitative social science approaches. Both the larvae and adult stages of this beetle are habitually consumed in the areas studied. In total, about 65% of consumers prefer consuming the adults, while 35% prefer consuming the larvae. About 24% of consumers derive the same satisfaction from the consumption of Augosoma or other edible insects. Close to 39% of consumers prefer other edible insects to Augosoma, while 37% prefer the consumption of Augosoma to other edible insects. This beetle usually occurs at a period when other edible insects are not available, therefore constituting a good source of alternative protein in this region where poverty, poaching, and biodiversity erosion are still a major problem. Furthermore, the gathering of this beetle for food is equally a means of biological pest control of raffia plants and a tool to enhance community-based conservation of the areas global biodiversity.

  15. Doassansiopsis caldesiae sp. nov. and Doassansiopsis tomasii: two remarkable smut fungi from Cameroon.

    Science.gov (United States)

    Piatek, Marcin; Vánky, Kálmán; Mossebo, Dominique C; Piatek, Jolanta

    2008-01-01

    Three recent collections of Doassansiopsis from western Cameroon are assessed taxonomically. Doassansiopsis caldesiae M. Piatek & Vánky is described as a new species from infected leaves of Caldesia reniformis (D. Don) Makino. Its diagnostic characters are flat, nonthickened sori with spore balls as blackish, slightly elevated dots, more or less globoid spores, conspicuous cortical sterile cells and parasitism on Caldesia reniformis of family Alismataceae. The species is compared to another Doassansiopsis species on host plants belonging to family Alismataceae. Doassansiopsis tomasii Vánky is described from two localities on Nymphaea nouchali Burm.f. var. caerulea (Savigny) Verdc. (Nymphaeaceae), which represents the first report of this smut from Cameroon and western Africa. Similarities between this species and Doassansiopsis nymphaeae (Syd. & P. Syd.) Thirum. and D. ticonis M. Piepenbr. are outlined and the global distribution of the three taxa is mapped. The species concept in the genus Doassansiopsis is discussed, and a key to all known species of the genus is provided. PMID:18833759

  16. An Examination of Forest Certification Status among Logging Companies in Cameroon.

    Science.gov (United States)

    Nukpezah, Daniel; Alemagi, Dieudonne; Duguma, Lalisa; Minang, Peter; Mbosso, Charlie; Tchoundjeu, Zac

    2014-01-01

    This paper assesses the level of interest, awareness, and adoption of ISO 14001 and Forest Stewardship Council (FSC) certification schemes among logging companies in Cameroon. Eleven logging companies located in Douala in the Littoral Region of Cameroon were assessed through a structured interview using an administered questionnaire which was mostly analyzed qualitatively thereafter. The findings indicated that none of the companies was certified for ISO 14001; however 63.64% of them were already FSC-certified. Four companies (36.36%) were neither FSC- nor ISO 14001 EMS-certified. Among the factors found to influence the adoption rate was the level of awareness about ISO 14001 and FSC certification schemes. The main drivers for pursuing FSC certification were easy penetration into international markets, tax holiday benefits, and enhancement of corporate image of the logging companies through corporate social responsibility fulfillments. Poor domestic market for certified products was found to be the major impediment to get certified. To make logging activities more environmentally friendly and socially acceptable, logging companies should be encouraged to get certified through the ISO 14001 EMS scheme which is almost nonexistent so far. This requires awareness creation about the scheme, encouraging domestic markets for certified products and creating policy incentives.

  17. Geomorphological Approach for Regional Zoning In The Merapi Volcanic Area

    Directory of Open Access Journals (Sweden)

    Langgeng Wahyu Santosa

    2013-07-01

    Full Text Available Geomorphologial approach can be used as the basic for identifying and analyzing the natural resources potentials, especially in volcanic landscape. Based on its geomorphology, Merapi volcanic landscape can be divided into 5 morphological units, i.e.: volcanic cone, volcanic slope, volcanic foot, volcanic foot plain, and fluvio-volcanic plain. Each of these morphological units has specific characteristic and natural resources potential. Based on the condition of geomorphology, the regional zoning can be compiled to support the land use planning and to maintain the conservation of environmental function in the Merapi Volcanic area.

  18. Climatic Impact of Volcanic Eruptions

    Directory of Open Access Journals (Sweden)

    Gregory A. Zielinski

    2002-01-01

    Full Text Available Volcanic eruptions have the potential to force global climate, provided they are explosive enough to emit at least 1–5 megaton of sulfur gases into the stratosphere. The sulfuric acid produced during oxidation of these gases will both absorb and reflect incoming solar radiation, thus warming the stratosphere and cooling the Earth’s surface. Maximum global cooling on the order of 0.2–0.3°C, using instrumental temperature records, occurs in the first 2 years after the eruption, with lesser cooling possibly up to the 4th year. Equatorial eruptions are able to affect global climate, whereas mid- to high-latitude events will impact the hemisphere of origin. However, regional responses may differ, including the possibility of winter warming following certain eruptions. Also, El Niño warming may override the cooling induced by volcanic activity. Evaluation of different style eruptions as well as of multiple eruptions closely spaced in time beyond the instrumental record is attained through the analysis of ice-core, tree-ring, and geologic records. Using these data in conjunction with climate proxy data indicates that multiple eruptions may force climate on decadal time scales, as appears to have occurred during the Little Ice Age (i.e., roughly AD 1400s–1800s. The Toba mega-eruption of ~75,000 years ago may have injected extremely large amounts of material into the stratosphere that remained aloft for up to about 7 years. This scenario could lead to the initiation of feedback mechanisms within the climate system, such as cooling of sea-surface temperatures. These interacting mechanisms following a mega-eruption may cool climate on centennial time scales.

  19. Report of the 7th international workshop on colposcopy, screening and prevention of cervical cancer, Douala, Cameroon, March 30 - 31 and April 1st 2016

    Directory of Open Access Journals (Sweden)

    Jovanny Tsuala Fouogue

    2016-09-01

    Conclusions: Master's classes, free communications and discussions were fruitful and appointment was taken for March 30-31, 2017 in Yaounde, Cameroon. [Int J Reprod Contracept Obstet Gynecol 2016; 5(9.000: 3269-3274

  20. Delayed entry into HIV care after diagnosis in two specialized care and treatment centres in Cameroon: the influence of CD4 count and WHO staging

    OpenAIRE

    Takah, Noah F.; Awungafac, George; Aminde, Leopold N.; Ali, Innocent; Ndasi, Juliana; Njukeng, Patrick

    2016-01-01

    Background Delayed entry into HIV care has complicated the challenges faced in sub-Saharan Africa due to the high HIV burden. A clear knowledge of the factors affecting delayed entry will be essential in directing interventions towards reducing delayed entry into HIV care. There exist very limited data on delayed entry in Cameroon despite its relevance; hence this study was conducted to determine the rate of delayed entry and its associated factors in HIV programmes in Cameroon. Methods Data ...

  1. Characterization of Bacillus anthracis-Like Bacteria Isolated from Wild Great Apes from Côte d'Ivoire and Cameroon

    OpenAIRE

    Klee, Silke R.; Özel, Muhsin; Appel, Bernd; Boesch, Christophe; Ellerbrok, Heinz; Jacob, Daniela; Holland, Gudrun; Leendertz, Fabian H; Pauli, Georg; Grunow, Roland; Nattermann, Herbert

    2006-01-01

    We present the microbiological and molecular characterization of bacteria isolated from four chimpanzees and one gorilla thought to have died of an anthrax-like disease in Côte d'Ivoire and Cameroon. These isolates differed significantly from classic Bacillus anthracis by the following criteria: motility, resistance to the gamma phage, and, for isolates from Cameroon, resistance to penicillin G. A capsule was expressed not only after induction by CO2 and bicarbonate but also under normal grow...

  2. Evidence of dengue virus transmission and factors associated with the presence of anti-dengue virus antibodies in humans in three major towns in Cameroon.

    OpenAIRE

    Maurice Demanou; Régis Pouillot; Marc Grandadam; Pascal Boisier; Basile Kamgang; Jean Pierre Hervé; Christophe Rogier; Dominique Rousset; Christophe Paupy

    2014-01-01

    Dengue is not well documented in Africa. In Cameroon, data are scarce, but dengue infection has been confirmed in humans. We conducted a study to document risk factors associated with anti-dengue virus Immunoglobulin G seropositivity in humans in three major towns in Cameroon.A cross sectional survey was conducted in Douala, Garoua and Yaounde, using a random cluster sampling design. Participants underwent a standardized interview and were blood sampled. Environmental and housing characterist...

  3. Evidence of dengue virus transmission and factors associated with the presence of anti-dengue virus antibodies in humans in three major towns in Cameroon

    OpenAIRE

    Demanou, Maurice; Pouillot, Régis; Grandadam, Marc; Boisier, Pascal; Kamgang, Basile; Hervé, Jean Pierre; Rogier, Christophe; Rousset, Dominique; Paupy, Christophe

    2014-01-01

    Background: Dengue is not well documented in Africa. In Cameroon, data are scarce, but dengue infection has been confirmed in humans. We conducted a study to document risk factors associated with anti-dengue virus Immunoglobulin G seropositivity in humans in three major towns in Cameroon. Methodology/Principal Findings: A cross sectional survey was conducted in Douala, Garoua and Yaounde, using a random cluster sampling design. Participants underwent a standardized interview and were blood sa...

  4. MISR Observations of Etna Volcanic Plumes

    Science.gov (United States)

    Scollo, S.; Kahn, R. A.; Nelson, D. L.; Coltelli, M.; Diner, D. J.; Garay, M. J.; Realmuto, V. J.

    2012-01-01

    In the last twelve years, Mt. Etna, located in eastern Sicily, has produced a great number of explosive eruptions. Volcanic plumes have risen to several km above sea level and created problems for aviation and the communities living near the volcano. A reduction of hazards may be accomplished using remote sensing techniques to evaluate important features of volcanic plumes. Since 2000, the Multiangle Imaging SpectroRadiometer (MISR) on board NASA s Terra spacecraft has been extensively used to study aerosol dispersal and to extract the three-dimensional structure of plumes coming from anthropogenic or natural sources, including volcanoes. In the present work, MISR data from several explosive events occurring at Etna are analyzed using a program named MINX (MISR INteractive eXplorer). MINX uses stereo matching techniques to evaluate the height of the volcanic aerosol with a precision of a few hundred meters, and extracts aerosol properties from the MISR Standard products. We analyzed twenty volcanic plumes produced during the 2000, 2001, 2002-03, 2006 and 2008 Etna eruptions, finding that volcanic aerosol dispersal and column height obtained by this analysis is in good agreement with ground-based observations. MISR aerosol type retrievals: (1) clearly distinguish volcanic plumes that are sulphate and/or water vapor dominated from ash-dominated ones; (2) detect even low concentrations of volcanic ash in the atmosphere; (3) demonstrate that sulphate and/or water vapor dominated plumes consist of smaller-sized particles compared to ash plumes. This work highlights the potential of MISR to detect important volcanic plume characteristics that can be used to constrain the eruption source parameters in volcanic ash dispersion models. Further, the possibility of discriminating sulphate and/or water vapor dominated plumes from ash-dominated ones is important to better understand the atmospheric impact of these plumes.

  5. Toward Forecasting Volcanic Eruptions using Seismic Noise

    CERN Document Server

    Brenguier, Florent; Campillo, Michel; Ferrazzini, Valerie; Duputel, Zacharie; Coutant, Olivier; Nercessian, Alexandre

    2007-01-01

    During inter-eruption periods, magma pressurization yields subtle changes of the elastic properties of volcanic edifices. We use the reproducibility properties of the ambient seismic noise recorded on the Piton de la Fournaise volcano to measure relative seismic velocity variations of less than 0.1 % with a temporal resolution of one day. Our results show that five studied volcanic eruptions were preceded by clearly detectable seismic velocity decreases within the zone of magma injection. These precursors reflect the edifice dilatation induced by magma pressurization and can be useful indicators to improve the forecasting of volcanic eruptions.

  6. Volcanic caves of East Africa - an overview

    Directory of Open Access Journals (Sweden)

    Jim W. Simons

    1998-01-01

    Full Text Available Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and areas are shortly reported.

  7. Molecular monitoring of plasmodium falciparum drug susceptibility at the time of the introduction of artemisinin-based combination therapy in Yaoundé, Cameroon: Implications for the future

    Directory of Open Access Journals (Sweden)

    Menard Sandie

    2012-04-01

    Full Text Available Abstract Background Regular monitoring of the levels of anti-malarial resistance of Plasmodium falciparum is an essential policy to adapt therapy and improve malaria control. This monitoring can be facilitated by using molecular tools, which are easier to implement than the classical determination of the resistance phenotype. In Cameroon, chloroquine (CQ, previously the first-line therapy for uncomplicated malaria was officially withdrawn in 2002 and replaced initially by amodiaquine (AQ monotherapy. Then, artemisinin-based combination therapy (ACT, notably artesunate-amodiaquine (AS-AQ or artemether-lumefantrine (AL, was gradually introduced in 2004. This situation raised the question of the evolution of P. falciparum resistance molecular markers in Yaoundé, a highly urbanized Cameroonian city. Methods The genotype of pfcrt 72 and 76 and pfmdr1 86 alleles and pfmdr1 copy number were determined using real-time PCR in 447 P. falciparum samples collected between 2005 and 2009. Results This study showed a high prevalence of parasites with mutant pfcrt 76 (83% and pfmdr1 86 (93% codons. On the contrary, no mutations in the pfcrt 72 codon and no samples with duplication of the pfmdr1 gene were observed. Conclusion The high prevalence of mutant pfcrt 76T and pfmdr1 86Y alleles might be due to the choice of alternative drugs (AQ and AS-AQ known to select such genotypes. Mutant pfcrt 72 codon was not detected despite the prolonged use of AQ either as monotherapy or combined with artesunate. The absence of pfmdr1 multicopies suggests that AL would still remain efficient. The limited use of mefloquine or the predominance of mutant pfmdr1 86Y codon could explain the lack of pfmdr1 amplification. Indeed, this mutant codon is rarely associated with duplication of pfmdr1 gene. In Cameroon, the changes of therapeutic strategies and the simultaneous use of several formulations of ACT or other anti-malarials that are not officially recommended result in a

  8. Origin and paleoenvironment of Pleistocene-Holocene Travertine deposit from the Mbéré sedimentary sub-basin along the Central Cameroon shear zone: Insights from petrology and palynology and evidence for neotectonics

    Science.gov (United States)

    Tchouatcha, Milan Stafford; Njoya, André; Ganno, Sylvestre; Toyama, Réné; Ngouem, Paul Aubin; Njiké Ngaha, Pierre Ricard

    2016-06-01

    The Mbéré sub-basin belongs to the Mbéré-Djerem intra-continental basin of Central North Cameroon. In this sub-basin, a travertine outcrop has been discovered and investigated palynologically and petrologically in this study. The sporopollinic content of the studied travertine is mainly composed of fungal spores (Rhyzophagites sp., Monoporisporites sp …) associated with rare fresh water algae spores such as Chomotriletes minor and angiosperm pollens (compositae, graminae, …). This sporopollinic association is indicative of hot and semi-arid to arid paleoclimate and reveals a Pleistocene-Holocene depositional age. The whole rock major element geochemistry shows relative enrichment of CaO (49.48%) and CO2 (38.49%). The origin of CO2 is probably from magmatic and/or metamorphic fluids. Compared to other travertines, SiO2 and Al2O3 contents are significant with average concentrations of 5.68% and 2.58% respectively. The mineralogical composition revealed by a microscopic study of bulk rocks is dominated by calcite (90-92%) associated to quartz (2-4%) and feldspar (2-3%), meanwhile the heavy mineral concentrate is formed by various mineral types such as zircon (most abundant), garnet, tourmaline, epidote, biotite, peridot and aegirine augite suggesting that the underground water has crossed both volcanic, plutonic and metamorphic rocks. With the mineral composition made of both chemical and detrital derived elements, the Mbéré travertine corresponds to chemico-lithoclastic/detrital limestone. In the Mbéré trough, numerous thermo-mineral springs are located along major fractures and faults. This result suggests that the Mbéré travertine deposit is related to the rising of deep water with the help of a fracturing system, similar to those of Irdi (Morocco), Italy and Turkey where there is much volcanism.

  9. Mapping the topography and cone morphology of the Dalinor volcanic swarm in Inner Mongolia with remote sensing and DEM data

    Science.gov (United States)

    Gong, Liwen; Li, Ni; Fan, Qicheng; Zhao, Yongwei; Zhang, Liuyi; Zhang, Chuanjie

    2016-09-01

    The Dalinor volcanic swarm, located south of Xilinhot, Inner Mongolia of China, was a result of multistage eruptions that occurred since the Neogene period. This swarm is mainly composed of volcanic cones and lava tablelands. The objective of this study is to map the topography and morphology of this volcanic swarm. It is based on a variety of data collected from various sources, such as the digital elevation model (DEM), Landsat images, and a 1:50,000 topographic map, in addition to various software platforms, including ArcGIS, Envi4.8, Global Mapper, and Google Earth for data processing and interpretation. The results show that the overall topography of the volcanic swarm is a platform with a central swell having great undulation, sizable gradient variations, a rough surface, and small terrain relief. According to the undulating characteristics of the line profile, the volcanic swarm can be divided into four stairs with heights of 1,280 m, 1,360 m, 1,440 m, and 1,500 m. The analysis of the swath profile characterizes the two clusters of volcanoes with different height ranges and evolution. The lava tablelands and volcanic cones are distributed in nearly EW-trending belts, where tableland coverage was delineated with superposed layers of gradients and degrees of relief. According to the morphology, the volcanic cones were classified into four types: conical, composite, dome, and shield. The formation causes and classification basis for each type of volcanic cone were analyzed and their parameters were extracted. The H/D ratios of all types of volcanic cones were then statistically determined and projected to create a map of volcanic density distribution. Based on the relationship between distribution and time sequence of the formation of different volcanic cones, it can be inferred that the volcanic eruptions migrated from the margins to the center of the lava plateau. The central area was formed through superposition of multi-stage eruptive materials. In addition

  10. Why Are Nigeria-Cameroon Chimpanzees (Pan troglodytes ellioti) Free of SIVcpz Infection?

    Science.gov (United States)

    Locatelli, Sabrina; Harrigan, Ryan J; Sesink Clee, Paul R; Mitchell, Matthew W; McKean, Kurt A; Smith, Thomas B; Gonder, Mary Katherine

    2016-01-01

    Simian immunodeficiency virus (SIV) naturally infects two subspecies of chimpanzee: Pan troglodytes troglodytes from Central Africa (SIVcpzPtt) and P. t. schweinfurtii from East Africa (SIVcpzPts), but is absent in P. t. verus from West Africa and appears to be absent in P. t. ellioti inhabiting Nigeria and western Cameroon. One explanation for this pattern is that P. t. troglodytes and P. t schweinfurthii may have acquired SIVcpz after their divergence from P. t. verus and P. t. ellioti. However, all of the subspecies, except P. t. verus, still occasionally exchange migrants making the absence of SIVcpz in P. t. ellioti puzzling. Sampling of P. t. ellioti has been minimal to date, particularly along the banks of the Sanaga River, where its range abuts that of P. t. troglodytes. This study had three objectives. First, we extended the sampling of SIVcpz across the range of chimpanzees north of the Sanaga River to address whether under-sampling might account for the absence of evidence for SIVcpz infection in P. t. ellioti. Second, we investigated how environmental variation is associated with the spread and prevalence of SIVcpz in the two chimpanzee subspecies inhabiting Cameroon since environmental variation has been shown to contribute to their divergence from one another. Finally, we compared the prevalence and distribution of SIVcpz with that of Simian Foamy Virus (SFV) to examine the role of ecology and behavior in shaping the distribution of diseases in wild host populations. The dataset includes previously published results on SIVcpz infection and SFVcpz as well as newly collected data, and represents over 1000 chimpanzee fecal samples from 41 locations across Cameroon. Results revealed that none of the 181 P. t. ellioti fecal samples collected across the range of P. t. ellioti tested positive for SIVcpz. In addition, species distribution models suggest that environmental variation contributes to differences in the distribution and prevalence of SIVcpz and

  11. Multiple insecticide resistance mechanisms in Anopheles gambiae s.l. populations from Cameroon, Central Africa

    Directory of Open Access Journals (Sweden)

    Nwane Philippe

    2013-02-01

    Full Text Available Abstract Background Increasing incidence of DDT and pyrethroid resistance in Anopheles mosquitoes is seen as a limiting factor for malaria vector control. The current study aimed at an in-depth characterization of An. gambiae s.l. resistance to insecticides in Cameroon, in order to guide malaria vector control interventions. Methods Anopheles gambiae s.l. mosquitoes were collected as larvae and pupae from six localities spread throughout the four main biogeographical domains of Cameroon and reared to adults in insectaries. Standard WHO insecticide susceptibility tests were carried out with 4% DDT, 0.75% permethrin and 0.05% deltamethrin. Mortality rates and knockdown times (kdt50 and kdt95 were determined and the effect of pre-exposure to the synergists DEF, DEM and PBO was assessed. Tested mosquitoes were identified to species and molecular forms (M or S using PCR-RFLP. The hot ligation method was used to depict kdr mutations and biochemical assays were conducted to assess detoxifying enzyme activities. Results The An. arabiensis population from Pitoa was fully susceptible to DDT and permethrin (mortality rates > 98% and showed reduced susceptibility to deltamethrin. Resistance to DDT was widespread in An. gambiae s.s. populations and heterogeneous levels of susceptibility to permethrin and deltamethrin were observed. In many cases, prior exposure to synergists partially restored insecticide knockdown effect and increased mortality rates, suggesting a role of detoxifying enzymes in increasing mosquito survival upon challenge by pyrethroids and, to a lower extent DDT. The distribution of kdr alleles suggested a major role of kdr-based resistance in the S form of An. gambiae. In biochemical tests, all but one mosquito population overexpressed P450 activity, whereas baseline GST activity was low and similar in all field mosquito populations and in the control. Conclusion In Cameroon, multiple resistance mechanisms segregate in the S form of An

  12. On the Role of Climate Forcing by Volcanic Sulphate and Volcanic Ash

    OpenAIRE

    Baerbel Langmann

    2014-01-01

    There is overall agreement that volcanic sulphate aerosols in the stratosphere can reduce solar radiation reaching the earth’s surface for years, thereby reducing surface temperatures, affecting global circulation patterns and generally the global climate system. However, the response of the climate system after large volcanic eruptions is not fully understood and global climate models have difficulties to reproduce the observed variability of the earth system after large volcanic eruptions u...

  13. Volcanic and sedimentary-rock aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Volcanic and sedimentary-rock aquifers in the states of Montana, Wyoming, Idaho, Nevada, California, Oregon, and...

  14. Volcanics in the Gulf Coast [volcanicg

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The volcanic provinces are modified after Plate 2, Principal structural features, Gulf of Mexico Basin (compiled by T.E. Ewing and R.F. Lopez) in Volume J, The...

  15. Volcanic Ash Advisory Database, 1983-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanic ash is a significant hazard to aviation and can also affect global climate patterns. To ensure safe navigation and monitor possible climatic impact, the...

  16. Measuring Disability in Population Based Surveys: The Interrelationship between Clinical Impairments and Reported Functional Limitations in Cameroon and India

    Science.gov (United States)

    2016-01-01

    Purpose To investigate the relationship between two distinct measures of disability: self-reported functional limitations and objectively-screened clinical impairments. Methods We undertook an all age population-based survey of disability in two areas: North-West Cameroon (August/October 2013) and Telangana State, India (Feb/April 2014). Participants were selected for inclusion via two-stage cluster randomised sampling (probability proportionate to size cluster selection and compact segment sampling within clusters). Disability was defined as the presence of self-reported functional limitations across eight domains, or presence of moderate or greater clinical impairments. Clinical impairment screening comprised of visual acuity testing for vision impairment, pure tone audiometry for hearing impairment, musculoskeletal functioning assessment for musculoskeletal impairment, reported seizure history for epilepsy and reported symptoms of clinical depression (depression adults only). Information was collected using structured questionnaires, observations and examinations. Results Self-reported disability prevalence was 5.9% (95% CI 4.7–7.4) and 7.5% (5.9–9.4) in Cameroon and India respectively. The prevalence of moderate or greater clinical impairments in the same populations were 8.4% (7.5–9.4) in Cameroon and 10.5% (9.4–11.7) in India. Overall disability prevalence (self-report and/or screened positive to a moderate or greater clinical impairment) was 10.5% in Cameroon and 12.2% in India, with limited overlap between the sub-populations identified using the two types of tools. 33% of participants in Cameroon identified to have a disability, and 45% in India, both reported functional limitations and screened positive to objectively-screened impairments, whilst the remainder were identified via one or other tool only. A large proportion of people with moderate or severe clinical impairments did not self-report functional difficulties despite reporting

  17. Medical effects of volcanic eruptions

    Science.gov (United States)

    Baxter, Peter J.

    1990-09-01

    Excluding famine and tsunamis, most deaths in volcanic eruptions have been from pyroclastic flows and surges (nuées ardentes) and wet debris flows (lahars). Information on the causes of death and injury in eruptions is sparse but the available literature is summarised for the benefit of volcanologists and emergency planners. In nuées, thermal injury may be at least as important as asphyxia in causing immediate deaths. The high temperature of the gases and entrained particles readily causes severe burns to the skin and the air passages and the presence of both types of injury in an individual may combine to increase the delayed mortality risk from respiratory complications or from infection of burns. Trauma from missiles or body displacement is also common, but the role of asphyxiant or irritant gases, and steam, remains unclear. The ratio of dead: injured is much higher than in other natural disasters. At the periphery of a nuée being protected inside buildings which remain intact appears to greatly increase the chances of survival. In lahars, infected wounds and crush injury are the main delayed causes of death, and the scope for preventive measures, other than evacuation, is small. The evidence from Mount St. Helens, 1980, and other major eruptions indicates that, although mortality is high within the main zone of devastation and in the open, emergency planning should concentrate on the periphery of a nuée where preventive measures are feasible and could save many lives in densely populated areas.

  18. Crossing the glass transition during volcanic eruptions

    OpenAIRE

    Richard, Dominique

    2015-01-01

    Predicting the occurrence and the evolving nature of volcanic eruptions remains an outstanding challenge. The complexity of volcanic Systems requires the use of many different approaches to gain a more profound understanding of the interplay of parameters such as magma temperature, composition, volatile content, cooling rate and viscosity as they interactively control the rheology of magma. This study focusses on three different scenarios in which the glass transition, a kinetic boundar...

  19. Volcanic ash detection by GPS signal

    OpenAIRE

    Aranzulla, M.; Dipartimento di Fisica e Astronomia, Università di Catania; Cannavò, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Scollo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Puglisi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Immè, G.; sita` degli studi di Catania

    2013-01-01

    We investigate the ability of GPS to detect volcanic plumes at Mt. Etna, Italy. We use a robust statistical approach to highlight whether the presence of a volcanic plume in the atmosphere may really affect the GPS undifferenced post-fit phase residuals. The proposed method has been tested for the September 4–5, 2007 activity of Mt. Etna. This eruption produced powerful lava fountains forming a weak, a few kilometers high plume for several hours, representing typical a...

  20. Cryogenic Origin for Mars Analog Carbonates in the Bockfjord Volcanic Complex Svalbard (Norway)

    Science.gov (United States)

    Amundsen, H. E. F.; Benning, L.; Blake, D. F.; Fogel, M.; Ming, D.; Skidmore, M.; Steele, A.

    2011-01-01

    The Sverrefjell and Sigurdfjell eruptive centers in the Bockfjord Volcanic Complex (BVC) on Svalbard (Norway) formed by subglacial eruptions ca. 1 Ma ago. These eruptive centers carry ubiquitous magnesian carbonate deposits including dolomitemagnesite globules similar to those in the Martian meteorite ALH84001. Carbonates in mantle xenoliths are dominated by ALH84001 type carbonate globules that formed during quenching of CO2-rich mantle fluids. Lava hosted carbonates include ALH84001 type carbonate globules occurring throughout lava vesicles and microfractures and massive carbonate deposits associated with vertical volcanic vents. Massive carbonates include cemented lava breccias associated with volcanic vents. Carbonate cements comprise layered deposits of calcite, dolomite, huntite, magnesite and aragonite associated with ALH84001 type carbonate globules lining lava vesicles. Combined Mossbauer, XRD and VNIR data show that breccia carbonate cements at Sverrefjell are analog to Comanche carbonates at Gusev crater.

  1. Differential absorption lidar for volcanic CO(2) sensing tested in an unstable atmosphere.

    Science.gov (United States)

    Queisser, Manuel; Burton, Mike; Fiorani, Luca

    2015-03-01

    Motivated by the need for an extremely durable and portable instrument to quantify volcanic CO(2) we have produced a corresponding differential absorption lidar (DIAL). It was tested on a volcano (Vulcano, Italy), sensing a non-uniform volcanic CO(2) signal under turbulent atmospheric conditions. The measured CO(2) mixing ratio trend agrees qualitatively well but quantitatively poorly with a reference CO(2) measurement. The disagreement is not in line with the precision of the DIAL determined under conditions that largely exclude atmospheric effects. We show evidence that the disagreement is mainly due to atmospheric turbulence. We conclude that excluding noise associated with atmospheric turbulence, as commonly done in precision analysis of DIAL instruments, may largely underestimate the error of measured CO(2) concentrations in turbulent atmospheric conditions. Implications for volcanic CO(2) sensing with DIAL are outlined. PMID:25836880

  2. Lunar volcanism in space and time

    Science.gov (United States)

    Head, J. W., III

    1976-01-01

    The role of lunar volcanism in the history of the moon is documented using lunar-orbit and earth-based data along with characterizations derived from Apollo and Luna sample-return missions. Characteristics of mare and highland volcanic features are described, Apollo and Luna results are discussed, and the characteristics of other mare deposits and of other highland features of possible volcanic origin are summarized. Major conclusions are that: (1) there is little unequivocal morphologic evidence for highland volcanism, (2) lunar mare lavas appear to have originated from depths of 100 to 500 km, (3) impact melting does not appear to have been a factor in the generation of mare lavas, (4) mare volcanism was characterized by massive outpourings of very fluid volatile-poor lava analogous to terrestrial flood basalts, (5) mare volcanism took place from 3.83 to about 2.5 billion years ago, (6) the preferential occurrence of mare deposits in large impact basins appears to be generically unrelated to basin formation, and (7) a thicker farside crust may be responsible for the distinctive nearside-farside asymmetry of mare deposits.

  3. Volcanic loading: The dust veil index

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, H.H. [Univ. of East Anglia, Norwich (United Kingdom). Climatic Research Unit

    1985-09-01

    Dust ejected into the high atmosphere during explosive volcanic eruptions has been considered as a possible cause for climatic change. Dust veils created by volcanic eruptions can reduce the amount of light reaching the Earth`s surface and can cause reductions in surface temperatures. These climatic effects can be seen for several years following some eruptions and the magnitude and duration of the effects depend largely on the density or amount of tephra (i.e. dust) ejected, the latitude of injection, and atmospheric circulation patterns. Lamb (1970) formulated the Dust Veil Index (DVI) in an attempt to quantify the impact on the Earth`s energy balance of changes in atmospheric composition due to explosive volcanic eruptions. The DVI is a numerical index that quantifies the impact on the Earth`s energy balance of changes in atmospheric composition due to explosive volcanic eruptions. The DVI is a numerical index that quantifies the impact of a particular volcanic eruptions release of dust and aerosols over the years following the event. The DVI for any volcanic eruptions are available and have been used in estimating Lamb`s dust veil indices.

  4. Awareness, attitudes and prevention of malaria in the cities of Douala and Yaoundé (Cameroon

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    Menze-Djantio Benjamin

    2011-09-01

    Full Text Available Abstract Background There is little information on the social perception of malaria and the use of prevention methods in Cameroon. This study was designed to assess knowledge, attitude and management of malaria in households living in the cities of Douala and Yaoundé. Results Over 82% of people interviewed associated malaria transmission to mosquito bites. Methods used for malaria prevention were: environmental sanitation 1645 (76.1%, use of bed nets 1491 (69%, insecticide spray/coils 265 (12.3% and netting of doors or windows 42 (1.9%. Bed net ownership was significantly high in Yaoundé (73.8% (P Conclusion The study revealed a high awareness of populations on malaria and ITNs. However some attitudes hindering the use of ITN or related to the management of clinical cases need further attention.

  5. Child labour in Yaoundé-Cameroon: Some lessons drawn from a survey on children

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    Simon A. Song Ntamack

    2005-12-01

    Full Text Available Although child labour is a phenomenon widely studied around the world, there are few papers that tackle the problem in Cameroon. The objective of this paper is to fill the gap by questioning the subject in Yaoundé, the capital city. But child labour phenomenon is analysed here from a questionnaire that has two distinctive features: (i the questionnaire is exclusively devoted to child labour, and (ii all the participants in the survey are exclusively children themselves. No adult (parent, guardian, elder, employer, etc. was consulted and given a chance to answer on behalf of a child. This process is extremely rare in child labour, since in general individuals other than children are requested to testify and answer inslead of children. While some results obtained from a standard Logit model on the determinant of child labour are well known, the others are either not known or insignificant. We suspect that the reason is the data collection.

  6. Examination of the effects of public spending and trade policy on real exchange rate in Cameroon

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    Victalice Ngimanang ACHAMOH

    2015-11-01

    Full Text Available The study adopts the inter-temporal model of Rodríguez (1989 and Edward (1989 extended in Elbadawi and Soto (1997 to empirically examine the effect of public expenditure and trade openness on the real exchange rate using Cameroon data from 1977 to 2010. After exploring some issues on exchange rate and reviewing the relevant literature, the study employs residual based-cointegration technique. All the variables were stationary at level form or first differences. Public spending significantly appreciates the real exchange likewise the trade openness variable in the longrun. The results of the study suggests that appreciation of real exchange rate could be prevented by contracting public spending or adopting restrictive trade measures especially in the long run.

  7. Manyu youths, belonging and the antinomies of patrimonial elite politics in contemporary Cameroon

    DEFF Research Database (Denmark)

    Orock, Rogers Tabe Egbe

    2013-01-01

    This article explores the social and political connections between youths and political elites from Manyu Division in South-Western Cameroon. Unlike several recent studies on youths in Africa, it focuses on educated youths from Manyu, exploring their strategies to secure greater political inclusion......, these do not always guarantee inclusion and success in social mobility for the youthful actors. For these youths, they felt their exclusion to be more a result of the obstructive character of middle-aged elites who were reticent to acknowledge the values of kinship, ethnicity, and patronage as valid basis...... and better chances for upward social mobility. With a critical attention to their discourses and practices, the article examines the disjuncture between the promise of Cameroon’s patrimonial state as an inclusive structure of political action and the sense of exclusion, anxiety, and uncertainty felt by many...

  8. Survey of the mineral status of pastures and small ruminants in the West Region of Cameroon

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    Njwe, RM.

    1988-01-01

    Full Text Available Four dominant grass species (Hyparrhenia rufa, Melinis minutiflora, Pennisetum purpureum and Sporobolus africanus of natural pastures of the West Region of Cameroon were sampled at 60 sites between September and November of 1985. The grass samples were analysed for calcium, phosphorus, potassium, magnesium, sodium, iron, mangenese, copper and zinc. Serum was also collected from goats and sheep at the same locations where forages were sampled and analysed for calcium, phosphorus, magnesium, zinc and copper. Results showed that P, Mg, A/a, Zn and Cu in forages were generally below the critical level stipulated to satisfy the requirements of grazing livestock in the tropics. Calcium was inadequate in the sera of goats and sheep where as P, Mg, Zn and Cu were adequate. Use of salt licks to supplement intake of mineral elements from grasses by goats and sheep is necessary in the region.

  9. Efficacy of fungicides on the progress of early blight and yield of potato in Cameroon

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    Fontera, DA.

    1992-01-01

    Full Text Available Five fungicides were evaluated during the 1990 and 1991 growing seasons in two locations in Cameroon for efficacy on the progress of early blight and yield of potato. Disease-progress curves fitted the logistic transformation better than the Gompertz. Fungicidal treatments reduced the rate of early blight progress and area under disease-progress curve (AUDPC. Early blight was more severe in the 1991 season and yields recorded in this season were lower than those in 1990. In both seasons, high yields were obtained in plots receiving six sprays maneb or mancozeb. Two sprays of Ridomil plus (12 % metalaxyl + 60 % cuprous oxide and six of cupric hydroxide also produced appreciable yields, while fosetyl-AI (three sprays provided the least yield increase. Yield losses in non-sprayed plots were estimated at 15.7-53.6 %. Yields were negatively correlated to AUDPC.

  10. Ecological status and sources of anthropogenic contaminants in mangroves of the Wouri River Estuary (Cameroon).

    Science.gov (United States)

    Fusi, Marco; Beone, Gian Maria; Suciu, Nicoleta Alina; Sacchi, Angela; Trevisan, Marco; Capri, Ettore; Daffonchio, Daniele; Din, Ndongo; Dahdouh-Guebas, Farid; Cannicci, Stefano

    2016-08-30

    Mangroves are critically threatened by human activities, despite the important ecosystem functions and services they provide. Mangroves in Cameroon represent no exception to the worldwide trend of mangrove destruction, especially around Douala, on the Wouri river estuary. In two sites around Douala, we assessed the presence of sterols, PAHs, PCBs, DEHP, DDT and its metabolite p,p'-DDE and potentially toxic metals in sediment samples. As a proxy of ecological quality, we measured the diversity and abundance of macrobenthos assemblages. We detected p,p'-DDE contamination, with concentrations higher than 3μgkg(-1) in 16 out of 26 samples which were attributed to recent widespread use of DDT. The detection of sterols revealed faecal contamination. Significant sensitivity of the macrobenthos to contaminants was revealed, with possible implications on the overall mangrove vulnerability to climate change and on the provision of ecosystem services to local populations.

  11. Complete genome sequence of a new bipartite begomovirus infecting fluted pumpkin (Telfairia occidentalis) plants in Cameroon.

    Science.gov (United States)

    Leke, Walter N; Khatabi, Behnam; Fondong, Vincent N; Brown, Judith K

    2016-08-01

    The complete genome sequence was determined and characterized for a previously unreported bipartite begomovirus from fluted pumpkin (Telfairia occidentalis, family Cucurbitaceae) plants displaying mosaic symptoms in Cameroon. The DNA-A and DNA-B components were ~2.7 kb and ~2.6 kb in size, and the arrangement of viral coding regions on the genomic components was like those characteristic of other known bipartite begomoviruses originating in the Old World. While the DNA-A component was more closely related to that of chayote yellow mosaic virus (ChaYMV), at 78 %, the DNA-B component was more closely related to that of soybean chlorotic blotch virus (SbCBV), at 64 %. This newly discovered bipartite Old World virus is herein named telfairia mosaic virus (TelMV). PMID:27262944

  12. Aflatoxin Contamination in Food and Body Fluids in Relation to Malnutrition and Cancer Status in Cameroon

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    Félicité M. Tchouanguep

    2010-01-01

    Full Text Available Aflatoxins are food contaminants usually associated with hepatitis, immunodepression, impairment of fertility and cancer. The present work was to determine the presence of aflatoxins in eggs, milk, urine, and blood samples that were collected from various sources and periods; and hepatitis B virus antigen in blood samples. Aflatoxin was found in eggs (45.2%, cow raw milk (15.9%, breast milk (4.8%, urine from kwashiorkor and marasmic kwashiorkor children (45.5%, and sera from primary liver cancer patients (63.9%; HbsAg was also detected in 69.4% of the serum samples, but there was no association between both factors. Both AF and hepatitis B virus seem to be risk factors that could increase the incidence and prevalence rates of malnutrition and cancer in Cameroon.

  13. Ecological status and sources of anthropogenic contaminants in mangroves of the Wouri River Estuary (Cameroon)

    KAUST Repository

    Fusi, Marco

    2016-07-07

    Mangroves are critically threatened by human activities, despite the important ecosystem functions and services they provide. Mangroves in Cameroon represent no exception to the worldwide trend of mangrove destruction, especially around Douala, on the Wouri river estuary. In two sites around Douala, we assessed the presence of sterols, PAHs, PCBs, DEHP, DDT and its metabolite p,p\\'-DDE and potentially toxic metals in sediment samples. As a proxy of ecological quality, we measured the diversity and abundance of macrobenthos assemblages. We detected p,p\\'-DDE contamination, with concentrations higher than 3μgkg-1 in 16 out of 26 samples which were attributed to recent widespread use of DDT. The detection of sterols revealed faecal contamination. Significant sensitivity of the macrobenthos to contaminants was revealed, with possible implications on the overall mangrove vulnerability to climate change and on the provision of ecosystem services to local populations. © 2016 Elsevier Ltd.

  14. Survey of Water Bugs in Bankim, a New Buruli Ulcer Endemic Area in Cameroon

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    Solange Meyin A. Ebong

    2012-01-01

    Full Text Available Buruli ulcer is a debitliating human skin disease with an unknown transmission mode although epidemiological data link it with swampy areas. Data available suggest that aquatic insects play a role in the dissemination and/or transmission of this disease. However, their biodiversity and biology remain poorly documented. We conducted an entomological survey in Bankim, Cameroon, an area recently described as endemic for Buruli ulcer in order to identify the commonly occurring aquatic bugs and document their relative abundance, diversity, and spatial distribution. Collection of aquatic bugs was realized over a period of one month by daily direct capture in different aquatic environments (streams, ponds, and rivers and through light traps at night. Globally, the data obtained showed the presence of five families (Belostomatidae, Naucoridae, Nepidae, Notonectidae, and Gerridae, their abundance, distribution and diversity varying according to the type of aquatic environments and light attraction.

  15. Survey of water bugs in bankim, a new buruli ulcer endemic area in cameroon.

    Science.gov (United States)

    Ebong, Solange Meyin A; Eyangoh, Sara; Marion, Estelle; Landier, Jordi; Marsollier, Laurent; Guégan, Jean-François; Legall, Philippe

    2012-01-01

    Buruli ulcer is a debitliating human skin disease with an unknown transmission mode although epidemiological data link it with swampy areas. Data available suggest that aquatic insects play a role in the dissemination and/or transmission of this disease. However, their biodiversity and biology remain poorly documented. We conducted an entomological survey in Bankim, Cameroon, an area recently described as endemic for Buruli ulcer in order to identify the commonly occurring aquatic bugs and document their relative abundance, diversity, and spatial distribution. Collection of aquatic bugs was realized over a period of one month by daily direct capture in different aquatic environments (streams, ponds, and rivers) and through light traps at night. Globally, the data obtained showed the presence of five families (Belostomatidae, Naucoridae, Nepidae, Notonectidae, and Gerridae), their abundance, distribution and diversity varying according to the type of aquatic environments and light attraction. PMID:22666273

  16. Ecological status and sources of anthropogenic contaminants in mangroves of the Wouri River Estuary (Cameroon).

    Science.gov (United States)

    Fusi, Marco; Beone, Gian Maria; Suciu, Nicoleta Alina; Sacchi, Angela; Trevisan, Marco; Capri, Ettore; Daffonchio, Daniele; Din, Ndongo; Dahdouh-Guebas, Farid; Cannicci, Stefano

    2016-08-30

    Mangroves are critically threatened by human activities, despite the important ecosystem functions and services they provide. Mangroves in Cameroon represent no exception to the worldwide trend of mangrove destruction, especially around Douala, on the Wouri river estuary. In two sites around Douala, we assessed the presence of sterols, PAHs, PCBs, DEHP, DDT and its metabolite p,p'-DDE and potentially toxic metals in sediment samples. As a proxy of ecological quality, we measured the diversity and abundance of macrobenthos assemblages. We detected p,p'-DDE contamination, with concentrations higher than 3μgkg(-1) in 16 out of 26 samples which were attributed to recent widespread use of DDT. The detection of sterols revealed faecal contamination. Significant sensitivity of the macrobenthos to contaminants was revealed, with possible implications on the overall mangrove vulnerability to climate change and on the provision of ecosystem services to local populations. PMID:27394634

  17. Environmental transmission of Mycobacterium ulcerans drives dynamics of Buruli ulcer in endemic regions of Cameroon

    Science.gov (United States)

    Garchitorena, Andrés; Ngonghala, Calistus N.; Texier, Gaëtan; Landier, Jordi; Eyangoh, Sara; Bonds, Matthew H.; Guégan, Jean-François; Roche, Benjamin

    2015-12-01

    Buruli Ulcer is a devastating skin disease caused by the pathogen Mycobacterium ulcerans. Emergence and distribution of Buruli ulcer cases is clearly linked to aquatic ecosystems, but the specific route of transmission of M. ulcerans to humans remains unclear. Relying on the most detailed field data in space and time on M. ulcerans and Buruli ulcer available today, we assess the relative contribution of two potential transmission routes -environmental and water bug transmission- to the dynamics of Buruli ulcer in two endemic regions of Cameroon. The temporal dynamics of Buruli ulcer incidence are explained by estimating rates of different routes of transmission in mathematical models. Independently, we also estimate statistical models of the different transmission pathways on the spatial distribution of Buruli ulcer. The results of these two independent approaches are corroborative and suggest that environmental transmission pathways explain the temporal and spatial patterns of Buruli ulcer in our endemic areas better than the water bug transmission.

  18. Cretaceous volcanic-intrusive magmatism in western Guangdong and its geological significance

    Institute of Scientific and Technical Information of China (English)

    GENG; Hongyan; XU; Xisheng; S.Y.O'Reilly; ZHAO; Ming; SUN; Tao

    2006-01-01

    Systematic zircon LA-ICPMS U-Pb dating reveals that Cretaceous volcanic-intrusive activities developed in western Guangdong. Representative volcanic rocks, i.e. Maanshan and Zhougongding rhyodacites, have zircon U-Pb isotopic ages of 100±1 Ma, and the intrusive ones including the Deqing monzonitic granite body and the Xinghua granodiorite body in the Shidong complex, as well as the Tiaocun granodiorite body in the Guangping complex yield ages of 99±2 Ma, ca.100 Ma, and 104±3 Ma respectively. The biotite-granites of the Shidong complex main body (461±35 Ma) and that of the Guangping complex (444±6 Ma) are Caledonian. In spite of the big time interval between Cretaceous volcanic-intrusive magmatisms and Caledonian intrusive ones, both of them are characterized by enrichment in Rb, Th, Ce, Zr, Hf, Sm, depletion in Ba, Nb, Ta, P, Ti, Eu, and weakly REE tetrad effect. Eu negative anomalies are: Cretaceous volcanic rocks (Eu/Eu*=0.74), Cretaceous intrusive rocks (Eu/Eu*=0.35-0.58), Caledonian biotite granites (Eu/Eu*=0.31-0.34). Studies of Sr-Nd isotope data show that all these igneous rocks have high initial 87Sr/86Sr ratios (0.7105-0.7518), and low εNd(t) values (-7.23--11.39) with their Nd two-stage model ages ranging from 1.6-2.0 Ga, which suggest that they all derived from the Proterozoic crustal basement of southeast China.The occurrence of Cretaceous volcanic-intrusive magmatisms in western Guangdong is related with the important lithospheric extension event in southeast China (including Nanling region) at ca. 100 Ma.The "volcanic line" defined by the large scale Mesozoic intermediate-acidic volcanic magmatisms in southeast China may further extend to the southwest margin of Nanling region.

  19. Epidemiology and genetic variability of HHV-8/KSHV in Pygmy and Bantu populations in Cameroon.

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    Edouard Betsem

    2014-05-01

    Full Text Available BACKGROUND: Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8 is the causal agent of all forms of Kaposi sarcoma. Molecular epidemiology of the variable K1 region identified five major subtypes exhibiting a clear geographical clustering. The present study is designed to gain new insights into the KSHV epidemiology and genetic diversity in Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: Bantu and Pygmy populations from remote rural villages were studied. Antibodies directed against latent nuclear antigens (LANA were detected by indirect immunofluorescence using BC3 cells. Peripheral blood cell DNAs were subjected to a nested PCR amplifying a 737 bp K1 gene fragment. Consensus sequences were phylogenetically analyzed. We studied 2,063 persons (967 females, 1,096 males, mean age 39 years, either Bantus (1,276 or Pygmies (787. The Bantu group was older (42 versus 35 years: P<10(-4. KSHV anti-LANA seroprevalence was of 37.2% (768/2063, with a significant increase with age (P<10(-4 but no difference according to sex. Seroprevalence, as well as the anti-LANA antibodies titres, were higher in Bantus (43.2% than in Pygmies (27.6% (P<10(-4, independently of age. We generated 29 K1 sequences, comprising 24 Bantus and five Pygmies. These sequences belonged to A5 (24 cases or B (five cases subtypes. They exhibited neither geographical nor ethnic aggregation. A5 strains showed a wide genetic diversity while the B strains were more homogenous and belonged to the B1 subgroup. CONCLUSION: These data demonstrate high KSHV seroprevalence in the two major populations living in Southern and Eastern Cameroon with presence of mostly genetically diverse A5 but also B K1 subtypes.

  20. Oral Health Status of the Elderly at Tonga, West Region, Cameroon

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    Yotat Michele Lolita

    2015-01-01

    Full Text Available Objectives. The aim of this study was to determine the oral health status of elderly persons in Tonga, West Region of Cameroon. Methodology. This is a cross-sectional study of persons of at least 65 years, living in Tonga village, West Region of Cameroon. Results. A total of 183 persons aged between 65 and 94 years, mean age of 73 years ±7 s.d., 83 (45,4% males, and 100 (54,6% females participated in the study. The most represented age range was 65–74 years (60.1%; 86 (47.3% and elders above 65 constituted 1.8% of the total population. More than a third 117 (41.4% had visible dental plaque, 117 (48,6% had periodontal pockets >4 mm, 153 (54,1% had teeth with total crown destruction, 70 (38.3% had not lost a tooth, 23 (12.6% had lost 1 tooth, 19 (10.4% have lost at least 2 teeth, 100 (55.7% were partially edentulous at the maxilla and 98 (53.6% at the mandible, 2 (1.1% were completely edentulous at the maxilla and 3 (1.6% at the mandible, and 3.8% had removable dentures. The mean DMF index was 6.11 and 69.4% had dental caries. Risk factors to dental caries were toothbrushing and tobacco consumption while dental plaque was associated to pocket depth of 4–6 mm. Barriers to oral health care included ignorance 47 (25.7%, financial difficulties 124 (67.8%, and distance to the nearest clinic 12 (6.5%. Conclusion. The oral status of the elderly was generally poor.

  1. Hepatitis B, HIV, and Syphilis Seroprevalence in Pregnant Women and Blood Donors in Cameroon.

    Science.gov (United States)

    Dionne-Odom, Jodie; Mbah, Rahel; Rembert, Nicole J; Tancho, Samuel; Halle-Ekane, Gregory E; Enah, Comfort; Welty, Thomas K; Tih, Pius M; Tita, Alan T N

    2016-01-01

    Objectives. We estimated seroprevalence and correlates of selected infections in pregnant women and blood donors in a resource-limited setting. Methods. We performed a cross-sectional analysis of laboratory seroprevalence data from pregnant women and voluntary blood donors from facilities in Cameroon in 2014. Rapid tests were performed to detect hepatitis B surface antigen, syphilis treponemal antibodies, and HIV-1/2 antibodies. Blood donations were also tested for hepatitis C and malaria. Results. The seroprevalence rates and ranges among 7069 pregnant women were hepatitis B 4.4% (1.1-9.6%), HIV 6% (3.0-10.2%), and syphilis 1.7% (1.3-3.8%) with significant variability among the sites. Correlates of infection in pregnancy in adjusted regression models included urban residence for hepatitis B (aOR 2.9, CI 1.6-5.4) and HIV (aOR 3.5, CI 1.9-6.7). Blood donor seroprevalence rates and ranges were hepatitis B 6.8% (5.0-8.8%), HIV 2.2% (1.4-2.8%), syphilis 4% (3.3-4.5%), malaria 1.9%, and hepatitis C 1.7% (0.5-2.5%). Conclusions. Hepatitis B, HIV, and syphilis infections are common among pregnant women and blood donors in Cameroon with higher rates in urban areas. Future interventions to reduce vertical transmission should include universal screening for these infections early in pregnancy and provision of effective prevention tools including the birth dose of univalent hepatitis B vaccine. PMID:27578957

  2. Strengths and weaknesses of the smallholder oil palm sector in Cameroon

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    Nkongho Raymond N.

    2014-03-01

    Full Text Available The present study is an evaluation of the current strengths and weaknesses of the oil palm smallholder sector in Cameroon, or more precisely of the non-industrial sector, as some holdings owned by elites can reach hundreds of hectares. A randomized sample of oil palm producers was chosen after categorization into elites, migrants, natives and company workers (past and present in four palm oil production basins in the Southern part of the country. 176 semi-structured questionnaires were administered. The production basins included: Eseka, Dibombari, Muyuka, and Lobe. Results from the study revealed that elites owned larger average areas (41.3 ha than the other categories of oil palm producers. All categories recorded low average plantation yields, ranging from 7 to 8.4 t FFB/ha/year (with minimum yields of 3 t FFB/ha. Though the elites showed better bargaining power and higher income, all categories of producers faced similar problems such as the high cost of inputs with no governmental subsidies, the difficulty in accessing loans with low interest rates and the use of rudimentary working tools. Despite such weaknesses, the sector also demonstrates some strengths such as the ability to impose little threat to the primary forest when compared to agro-industrial plantations, the availability of a domestic and sub-regional market for red palm oil, the availability of artisanal mills with low extraction rates although able to generate more income for the producers. There is a need for governmental policies that will strengthen partnership between small and medium oil palm producers and agro-industries as it was the case during the Fonader period, in order to converge with the poverty reduction strategy intiated by the government of Cameroon.

  3. A survey of knowledge, attitudes and practice of emergency contraception among university students in Cameroon

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    Kouam Luc

    2007-07-01

    Full Text Available Abstract Background Unsafe abortion is a major public health problem in low-and-middle income countries. Young and unmarried women constitute a high risk group for unsafe abortions. It has been estimated that widespread use of emergency contraception may significantly reduce the number of abortion-related morbidity and mortality. The purpose of this study was to evaluate the knowledge, attitudes and experiences on emergency contraceptive pills by the university students in Cameroon in order to develop and refine a national health programme for reducing unwanted pregnancies and their associated morbidity and mortality. Methods A convenient sample of 700 students of the University of Buea (Cameroon was selected for the study. Data was collected by a self-administered, anonymous and pre-tested questionnaire. Results The response rate was 94.9% (664/700. General level of awareness of emergency contraceptive pills was 63.0% (418/664. However, knowledge of the general features of emergency contraceptive pills was low and misinformation was high among these students. Knowledge differed according to the source of information: informal source was associated with misinformation, while medical and informational sources were associated with better knowledge. Although the students generally had positive attitudes regarding emergency contraceptive pills, up to 65.0% (465/664 believed that emergency contraceptive pills were unsafe. Those with adequate knowledge generally showed favourable attitudes with regards to emergency contraceptive pills (Mann-Whitney U = 2592.5, p = 0.000. Forty-nine students (7.4% had used emergency contraceptive pills themselves or had a partner who had used them. Conclusion Awareness of emergency contraception pills by Cameroonian students is low and the method is still underused. Strategies to promote use of emergency contraception should be focused on spreading accurate information through medical and informational sources, which

  4. Microbiological water quality monitoring in a resource-limited urban area: a study in Cameroon, Africa

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    Andrew W. Nelson

    2012-10-01

    Full Text Available In resource-limited developing nations, such as Cameroon, the expense of modern water-quality monitoring techniques is prohibitive to frequent water testing, as is done in the developed world. Inexpensive, shelf-stable 3M™ Petrifilm™ Escherichia coli/Coliform Count Plates potentially can provide significant opportunity for routine water-quality monitoring in the absence of infrastructure for state-of-the-art testing. We used shelf-stable E. coli/coliform culture plates to assess the water quality at twenty sampling sites in Kumbo, Cameroon. Culture results from treated and untreated sources were compared to modern bacterial DNA pyrosequencing methods using established bioinformatics and statistical tools. Petrifilms were reproducible between replicates and sampling dates. Additionally, cultivation on Petrifilms suggests that treatment by the Kumbo Water Authority (KWA greatly improves water quality as compared with untreated river and rainwater. The majority of sequences detected were representative of common water and soil microbes, with a minority of sequences (<40% identified as belonging to genera common in fecal matter and/or causes of human disease. Water sources had variable DNA sequence counts that correlated significantly with the culture count data and may therefore be a proxy for bacterial load. Although the KWA does not meet Western standards for water quality (less than one coliform per 100 mL, KWA piped water is safer than locally available alternative water sources such as river and rainwater. The culture-based technology described is easily transferrable to resource-limited areas and provides local water authorities with valuable microbiological safety information with potential to protect public health in developing nations.

  5. Floods and mangrove forests, friends or foes? Perceptions of relationships and risks in Cameroon coastal mangroves

    Science.gov (United States)

    Munji, Cecilia A.; Bele, Mekou Y.; Idinoba, Monica E.; Sonwa, Denis J.

    2014-03-01

    Faced with the growing influence of climate change on climate driven perturbations such as flooding and biodiversity loss, managing the relationship between mangroves and their environment has become imperative for their protection. Hampering this is the fact that the full scope of the threats faced by specific mangrove forests is not yet well documented. Amongst some uncertainties is the nature of the relationship/interaction of mangroves with climate driven perturbations prevalent in their habitat such as coastal floods. We investigated the relationship between coastal flooding and mangrove forest stabilization, identify perceptions of flood risk and responses to offset identified effects. Random household surveys were carried out within four communities purposively sampled within the Cap Cameroon. Coastal changes were investigated over a period of 43 years (1965-2008). Seasonal flooding improved access to mangrove forests and hence promoted their exploitation for non-timber forest products (NTFPs) such as fuel wood and mangrove poles. 989 ha of mangrove forests were estimated to be lost over a period of 43 years in Cap Cameroon with implications on forest resources base, ecosystem stability, and livelihoods. Alternative livelihood activities were found to be carried out to moderate interruptions in fishing, with associated implications for mangrove forest dynamics. Respondents were of the opinion that risks associated with floods and mangrove deforestation will pose a major challenge for sustainable management of mangroves. These locally relevant perceptions and responses should however enable the identification of pertinent needs, challenges and opportunities to inform and orient effective decision-making, and to facilitate the development and participation in adaptive management strategies.

  6. Retention in an antiretroviral therapy programme during an era of decreasing drug cost in Limbe, Cameroon

    Directory of Open Access Journals (Sweden)

    Mosoko Jembia J

    2011-06-01

    Full Text Available Abstract Background In 2002, Cameroon initiated scale up of antiretroviral therapy (ART; on 1 October 2004, a substantial reduction in ART cost occurred. We assessed the impact of this event and other factors on enrolment and retention in care among HIV-infected patients initiating ART from February 2002 to December 2005 at the single ART clinic serving the Southwest Region in Limbe, Cameroon. Methods We retrospectively analyzed clinical and pharmacy payment records of HIV-infected patients initiating ART according to national guidelines. We compared two cohorts of patients, enrolled before and after 1 October 2004, to determine if price reduction was associated with enhanced enrolment. We assessed factors associated with retention and survival by Cox proportional hazards models. Retention in care implied patients who had contact with the healthcare system as of 31 December 2005 (including those who were transferred to continue care in other ART centres, although these patients may have interrupted therapy at some time. A patient who was not retained in care may have dropped out (lost to follow up or died. Results Mean enrolment rates for 2920 patients who initiated ART before and after the price reduction were 46.5 and 95.5 persons/month, respectively (p Conclusions Reducing the cost of ART increased enrolment of clients in the programme, but did not change retention in care. In a system where most clients pay for ART, an accessible clinic location may be more important than the cost of medication for retention in care. Decentralizing ART clinics might improve retention and survival among patients on ART.

  7. Household and community socioeconomic and environmental determinants of child nutritional status in Cameroon

    Directory of Open Access Journals (Sweden)

    Pongou Roland

    2006-04-01

    Full Text Available Abstract Background Undernutrition is a leading cause of child mortality in developing countries, especially in sub-Saharan Africa. We examine the household and community level socioeconomic and environmental factors associated with child nutritional status in Cameroon, and changes in the effects of these factors during the 1990s economic crisis. We further consider age-specific effects of household economic status on child nutrition. Methods Child nutritional status was measured by weight-for-age (WAZ and height-for-age (HAZ z-scores. Data were from Demographic and Health Surveys conducted in 1991 and 1998. We used analysis of variance to assess the bivariate association between the explanatory factors and nutritional status. Multivariate, multilevel analyses were undertaken to estimate the net effects of both household and community factors. Results Average WAZ and HAZ declined respectively from -0.70 standard deviations (SD, i.e. 0.70 SD below the reference median, to -0.83 SD (p = 0.006 and from -1.03 SD to -1.14 SD (p = 0.026 between 1991 and 1998. These declines occurred mostly among boys, children over 12 months of age, and those of low socioeconomic status. Maternal education and maternal health seeking behavior were associated with better child nutrition. Household economic status had an overall positive effect that increased during the crisis, but it had little effect in children under 6 months of age. Improved household (water, sanitation and cooking fuel and community environment had positive effects. Children living in the driest regions of the country were consistently worst off, and those in the largest cities were best off. Conclusion Both household and community factors have significant impact on child health in Cameroon. Understanding these relationships can facilitate design of age- and community-specific intervention programs.

  8. Heat impact on schoolchildren in Cameroon, Africa: potential health threat from climate change

    Directory of Open Access Journals (Sweden)

    Tord Kjellstrom

    2010-11-01

    Full Text Available Background: Health impacts related to climate change are potentially an increasing problem in Cameroon, especially during hot seasons when there are no means for protective and adaptive actions. Objective: To describe environmental conditions in schools and to evaluate the impact of heat on schoolchildren's health during school days in the Cameroon cities of Yaoundé and Douala. Methods: Schoolchildren (N=285 aged 12–16 years from public secondary schools completed a questionnaire about their background, general symptoms, and hot feelings in a cross-sectional study. In Yaoundé, 50 schoolchildren were individually interviewed during school days about hourly symptoms (fatigue, headache, and feeling very hot and performance. Lascar dataloggers were used to measure indoor classroom temperatures and humidity. Results: There was a significant correlation between daily indoor temperature and the percentages of schoolchildren who felt very hot, had fatigue, and headaches in Yaoundé. A high proportion of schoolchildren felt very hot (48%, had fatigue (76%, and headaches (38% in Yaoundé. Prevalences (% were higher among girls than boys for headaches (58 vs 39, feeling ‘very hot overall’ (37 vs 21, and ‘very hot in head’ (21 vs 18. Up to 62% were absentminded and 45% had slow writing speed. High indoor temperatures of 32.5°C in Yaoundé and 36.6°C in Douala were observed in school. Conclusions: Headache, fatigue, and feeling very hot associated with high indoor air temperature were observed among schoolchildren in the present study. Longitudinal data in schools are needed to confirm these results. School environmental conditions should be improved in order to enhance learning.

  9. Chronic non-communicable diseases in Cameroon - burden, determinants and current policies

    Directory of Open Access Journals (Sweden)

    Echouffo-Tcheugui Justin B

    2011-11-01

    Full Text Available Abstract Cameroon is experiencing an increase in the burden of chronic non-communicable diseases (NCDs, which accounted for 43% of all deaths in 2002. This article reviews the published literature to critically evaluate the evidence on the frequency, determinants and consequences of NCDs in Cameroon, and to identify research, intervention and policy gaps. The rising trends in NCDs have been documented for hypertension and diabetes, with a 2-5 and a 10-fold increase in their respective prevalence between 1994 and 2003. Magnitudes are much higher in urban settings, where increasing prevalence of overweight/obesity (by 54-82% was observed over the same period. These changes largely result from the adoption of unfavorable eating habits, physical inactivity, and a probable increasing tobacco use. These behavioral changes are driven by the economic development and social mobility, which are part of the epidemiologic transition. There is still a dearth of information on chronic respiratory diseases and cancers, as well as on all NDCs and related risk factors in children and adolescents. More nationally representative data is needed to tract risk factors and consequences of NCDs. These conditions are increasingly been recognized as a priority, mainly through locally generated evidence. Thus, national-level prevention and control programs for chronic diseases (mainly diabetes and hypertension have been established. However, the monitoring and evaluation of these programs is necessary. Budgetary allocations data by the ministry of health would be helpful, to evaluate the investment in NCDs prevention and control. Establishing more effective national-level tobacco control measures and food policies, as well as campaigns to promote healthy diets, physical activity and tobacco cessation would probably contribute to reducing the burden of NCDs.

  10. Hepatitis B, HIV, and Syphilis Seroprevalence in Pregnant Women and Blood Donors in Cameroon

    Directory of Open Access Journals (Sweden)

    Jodie Dionne-Odom

    2016-01-01

    Full Text Available Objectives. We estimated seroprevalence and correlates of selected infections in pregnant women and blood donors in a resource-limited setting. Methods. We performed a cross-sectional analysis of laboratory seroprevalence data from pregnant women and voluntary blood donors from facilities in Cameroon in 2014. Rapid tests were performed to detect hepatitis B surface antigen, syphilis treponemal antibodies, and HIV-1/2 antibodies. Blood donations were also tested for hepatitis C and malaria. Results. The seroprevalence rates and ranges among 7069 pregnant women were hepatitis B 4.4% (1.1–9.6%, HIV 6% (3.0–10.2%, and syphilis 1.7% (1.3–3.8% with significant variability among the sites. Correlates of infection in pregnancy in adjusted regression models included urban residence for hepatitis B (aOR 2.9, CI 1.6–5.4 and HIV (aOR 3.5, CI 1.9–6.7. Blood donor seroprevalence rates and ranges were hepatitis B 6.8% (5.0–8.8%, HIV 2.2% (1.4–2.8%, syphilis 4% (3.3–4.5%, malaria 1.9%, and hepatitis C 1.7% (0.5–2.5%. Conclusions. Hepatitis B, HIV, and syphilis infections are common among pregnant women and blood donors in Cameroon with higher rates in urban areas. Future interventions to reduce vertical transmission should include universal screening for these infections early in pregnancy and provision of effective prevention tools including the birth dose of univalent hepatitis B vaccine.

  11. Cattle productivity on smallholder farms in the Western Highlands of Cameroon

    International Nuclear Information System (INIS)

    A study of the traditional cattle production systems in the Western Highlands of Cameroon was carried out between August 1994 and September 1997. Fifty two cows selected from 14 farms in 4 locations were monitored monthly. Data were collected on calf and dam weight, dam's body condition, milk offtake and forage quality. Reproductive performance was monitored by measuring progesterone levels in milk sampled weekly. Crude protein content of grazed pastures rose from 12.5% in July to 14.5% in October and declined steadily to reach 4.5% in February. With such a decline in forage quality during the dry season, cows are unable to obtain their nutrient needs, thus productivity was low. Body condition score declined from medium (5.6) at calving to upper low (4.5) 4 months after the initiation of milk offtake. Body weight of cows decreased by nearly 14% during the same period. The interval between calving to first progesterone rise, calving to conception, and inter-calving intervals were 172 ± 116, 185 ± 106 and 448 ± 86 days, respectively. Milk offtake averaged 1.29 ± 0.44 kg/cow/day for a lactation length of 10.5 months. A significant effect of season was detected in milk offtake (P <0.001), body condition score (P <0.05), body weight of cows (P <0.05), intervals from calving to first progesterone rise (P <0.05), calving to conception (P <0.05) and inter-calving interval (P <0.01). Supplementary feeding during the dry season and early lactation to cover the nutrient requirements of the cows in the traditional production system of Western Highlands of Cameroon is recommended and forms the purpose of the second part of this study which is now underway. (author)

  12. Oral Health Status of the Elderly at Tonga, West Region, Cameroon

    Science.gov (United States)

    Michele Lolita, Yotat; Ashu Michael, Agbor; Hubert, Ntumba; Florence, Djachechi; Jacques, Bolenge

    2015-01-01

    Objectives. The aim of this study was to determine the oral health status of elderly persons in Tonga, West Region of Cameroon. Methodology. This is a cross-sectional study of persons of at least 65 years, living in Tonga village, West Region of Cameroon. Results. A total of 183 persons aged between 65 and 94 years, mean age of 73 years ±7 s.d., 83 (45,4%) males, and 100 (54,6%) females participated in the study. The most represented age range was 65–74 years (60.1%); 86 (47.3%) and elders above 65 constituted 1.8% of the total population. More than a third 117 (41.4%) had visible dental plaque, 117 (48,6%) had periodontal pockets >4 mm, 153 (54,1%) had teeth with total crown destruction, 70 (38.3%) had not lost a tooth, 23 (12.6%) had lost 1 tooth, 19 (10.4%) have lost at least 2 teeth, 100 (55.7%) were partially edentulous at the maxilla and 98 (53.6%) at the mandible, 2 (1.1%) were completely edentulous at the maxilla and 3 (1.6%) at the mandible, and 3.8% had removable dentures. The mean DMF index was 6.11 and 69.4% had dental caries. Risk factors to dental caries were toothbrushing and tobacco consumption while dental plaque was associated to pocket depth of 4–6 mm. Barriers to oral health care included ignorance 47 (25.7%), financial difficulties 124 (67.8%), and distance to the nearest clinic 12 (6.5%). Conclusion. The oral status of the elderly was generally poor. PMID:26633972

  13. Hepatitis B, HIV, and Syphilis Seroprevalence in Pregnant Women and Blood Donors in Cameroon

    Science.gov (United States)

    Mbah, Rahel; Rembert, Nicole J.; Tancho, Samuel; Halle-Ekane, Gregory E.; Enah, Comfort; Welty, Thomas K.; Tih, Pius M.; Tita, Alan T. N.

    2016-01-01

    Objectives. We estimated seroprevalence and correlates of selected infections in pregnant women and blood donors in a resource-limited setting. Methods. We performed a cross-sectional analysis of laboratory seroprevalence data from pregnant women and voluntary blood donors from facilities in Cameroon in 2014. Rapid tests were performed to detect hepatitis B surface antigen, syphilis treponemal antibodies, and HIV-1/2 antibodies. Blood donations were also tested for hepatitis C and malaria. Results. The seroprevalence rates and ranges among 7069 pregnant women were hepatitis B 4.4% (1.1–9.6%), HIV 6% (3.0–10.2%), and syphilis 1.7% (1.3–3.8%) with significant variability among the sites. Correlates of infection in pregnancy in adjusted regression models included urban residence for hepatitis B (aOR 2.9, CI 1.6–5.4) and HIV (aOR 3.5, CI 1.9–6.7). Blood donor seroprevalence rates and ranges were hepatitis B 6.8% (5.0–8.8%), HIV 2.2% (1.4–2.8%), syphilis 4% (3.3–4.5%), malaria 1.9%, and hepatitis C 1.7% (0.5–2.5%). Conclusions. Hepatitis B, HIV, and syphilis infections are common among pregnant women and blood donors in Cameroon with higher rates in urban areas. Future interventions to reduce vertical transmission should include universal screening for these infections early in pregnancy and provision of effective prevention tools including the birth dose of univalent hepatitis B vaccine.

  14. Cameroon; 2010: Article IV Consultation: Staff Report; Debt Sustainability Analysis; Staff Report Supplement; Public Information Notice on the Executive Board Discussion; and Statement by the Executive Director for Cameroon

    OpenAIRE

    International Monetary Fund

    2010-01-01

    Cameroon showed incipient signs of recovery from the global financial crisis. Although growth performance remained constrained under the Poverty Reduction Growth Facility (PRGF), tax and customs administrations were strengthened, macroeconomic stability was preserved, and debt relief under the Heavily Indebted Poor Countries (HIPC) and Multilateral Debt Relief Initiatives (MDRI) helped firm up debt sustainability. Executive Directors welcomed the new program aimed to accelerate growth through...

  15. Prevalence of hepatitis C virus and other blood-borne viruses in Pygmies and neighbouring Bantus in southern Cameroon.

    Science.gov (United States)

    Kowo, M P; Goubau, P; Ndam, E C; Njoya, O; Sasaki, S; Seghers, V; Kesteloot, H

    1995-01-01

    The prevalences of antibodies to hepatitis C virus (anti-HCV), human immunodeficiency virus (anti-HIV), human T lymphotrophic virus (anti-HTLV) and of hepatitis B surface antigen (HbsAg) were determined in 168 subjects aged 12 years and over (108 Pygmies, 60 Bantus) living in south Cameroon. In 167 subjects, we found an estimated minimal anti-HCV prevalence of 13%. The prevalence was significantly higher in Bantus (31.7%) than in Pygmies (11.1%) and increased with age in both groups, albeit more rapidly in Bantus. The overall prevalence of HBsAg was 7.2% and correlated with neither sex nor ethnic group. No association was found between anti-HCV and HbsAg prevalence rates. No subject was confirmed to be positive for HTLV or HIV. These findings confirm the high prevalence of HCV infection in south Cameroon and indicate that even secluded population groups are affected.

  16. Attainment of MDGs through tourism in the Central African sub-region: Implications for local economic development in Cameroon

    Directory of Open Access Journals (Sweden)

    Albert N. Kimbu

    2012-03-01

    Full Text Available This paper examines the role and contribution of tourism to local economic development and in the attainment of the Millennium Development Goals one and seven dealing with extreme poverty alleviation and environmental sustainability in the biodiversity endowed Central African sub-region. The concepts of sustainable tourism development and local economic development (in sub-Saharan Africa are examined. Through field observations and semi-structured interviews with 21 tourism industry stakeholders in Cameroon, an analysis of tourism’s role and future in LED and in the attainment of the Millennium Development Goals 1 & 7 is undertaken. The core challenges presently inhibiting tourism’s development thereby limiting its contribution to local economic development and the attainment of these goals in Cameroon are identified and a framework within which tourism’s contribution can be increased is proposed.

  17. Impacts of Type of Fallow and Invasion by Chromolaena odorata on Weed Communities in Crop Fields in Cameroon

    OpenAIRE

    Morag McDonald; Martine Ngobo; Stephan Weise

    2004-01-01

    In the humid forest regions of southern Cameroon in central Africa, sectoral and macroeconomic policy reforms introduced in the late 1980s have led to intensified land use, which in turn has resulted in, among other environmental consequences, shortened fallow systems dominated by the Asteraceae shrub, Chromolaena odorata (L.) King and Robinson, rather than by secondary forest species. A trial was established to determine the effect of shortened fallow duration and invasion by C. odorata on t...

  18. Taxonomy of Atlantic Central African orchids 5. A new species of Angraecum sect. Conchoglossum ( Orchidaceae , Angraecinae ) from Gabon and Cameroon

    OpenAIRE

    Ječmenica,Vladimir; Droissart, Vincent; Noret, Nausicaa; Stévart, Tariq

    2016-01-01

    Abstract Recent field inventories and taxonomic research in Central Africa have resulted in the discovery of many new orchid species. Five specimens of an apparently new Angraecum species were collected in Gabon and Cameroon. They stand out for their hanging habit and short zig-zag stem. Morphology of leaves and habit is somewhat comparable to Angraecum cultriforme and Angraecum stolzii , two species from East Africa. Flowers of the novelty share the general morphology of Angraecum pyriforme ...

  19. Taxonomy of Atlantic Central African orchids 2. A second species of the rare genus Distylodon (Orchidaceae, Angraecinae) collected in Cameroon

    OpenAIRE

    Vincent Droissart; Cribb,Phillip J.; Murielle Simo-Droissart; Tariq Stévart

    2014-01-01

    While conducting field inventories in South Cameroon, we collected two specimens of a new species that we considered to belong to the genus Angraecopsis. Afterwards, a careful examination of specimens housed at main herbaria, along with the nomenclatural types, allows us to place it in Distylodon, a monotypic genus previously known from East Africa. Distylodon sonkeanum Droissart, Stévart & P.J.Cribb, sp. nov. was collected in the lowland coastal forest of Atlantic Central Africa. ...

  20. What determines the price received by cocoa farmers in Cameroon? An empirical analysis based on bargaining theory

    OpenAIRE

    Kamdem, Cyrille Bergaly; Galtier, Franck; Gockowski, James; Helene, David-Benz; Johny EGG; Dia, Bernadette Kamgnia

    2010-01-01

    Studies have shown that small-scale agricultural producers from developing countries do not generally obtain the potential gains of trade. To investigate what can be done to help them get better prices, we examine ways to increase their bargaining power. Using data from 1,854 cocoa transactions between traders and producers in Cameroon during the 2005/2006 season, we show that when the bargaining situation is least favorable to the producers (because prices are non-negotiable due to interlink...

  1. Pollution and Siltation of Rivers in the Western Highlands of Cameroon: a Consequence of Farmland Erosion by Runoff

    OpenAIRE

    Djoukeng, Henri Grisseur; Tankou, Christopher Mubeteneh; Degré, Aurore

    2014-01-01

    In the western highlands agro-ecological zone of Cameroon, rivers are constantly silted and polluted with waste from cultivated plots. This study investigated on the characterization and quantification of sediment from plots cultivated in the watershed Méloh; among these sediment we highlighted soil, plant residues, chemical packages and plastic casing used for irrigation. In a natural rocky bottom wells, we performed for a period of three years the collection, differentiation and measurement...

  2. Analysis of Constraints to Agricultural Production in the Sudano Savanna Zone of Cameroon and Implication for Research Priority Setting

    OpenAIRE

    M'Biandoum, M.; Njoya, A.; Kenga, R.

    2005-01-01

    A participatory rural appraisal (PRA) survey approach was used to identify the major constraints to agricultural production and to describe the major production systems in the sudano savanna and sudano sahelian zone of northern Cameroon. Relative emphasis was placed on the household level characterization to have a better understanding of the land use system, farmers' constraints to production and opportunities, so as to better target agricultural technologies and interventions in this vast a...

  3. An Implementation of Total Quality Management and Its Impact on The Performance of Food and Beverage Industry of Cameroon

    OpenAIRE

    Gome Tsamo, Natacha Fabiola

    2014-01-01

    The prime notion of this project is to evaluate the implementation of Total Quality Management and its impact on organisational performance. The research is focused on the Food and Beverage Industry of Cameroon. In order to achieve the research goals and objective, primary and secondary data collection methods are used. The use of questionnaires and conducting interviews are essential as they assist in providing credible and valid data. Regression analysis is also used as it helped with the p...

  4. The Demarcation of Straddling Villages in Accordance with the International Court of Justice Jurisprudence: The Cameroon-Nigeria Experience

    OpenAIRE

    Oduntan, Gbenga

    2006-01-01

    The existence of straddling settlements between Cameroon and Nigeria is one of the features of their geographical location as neighbouring West African States. Although the existence of these settlements did not constitute a central part of the boundary dispute between both States, implementation of the recent World Court judgment presents crucial dilemmas as to the treatment of straddling communities in particular and, to some extent, boundary villages as well. This article explores the alte...

  5. Evaluation of bovine (Bos indicus) ovarian potential for in vitro embryo production in the Adamawa plateau (Cameroon)

    OpenAIRE

    Kouamo, J.; Dawaye, S.M.; Zoli, A. P.; Bah, G. S.

    2014-01-01

    An abattoir study was conducted to evaluate the ovarian potential of 201 local zebu cattle from Ngaoundere, Adamawa region (Cameroon) for in vitro embryo production (IVEP). The ovaries were excised, submerged in normal saline solution (0.9%) and transported to the laboratory for a detailed evaluation. Follicles on each ovary were counted, their diameters (Φ) measured and were grouped into 3 categories: small (Φ 8 mm). Each ovary was then sliced in...

  6. Diversity and dynamics of mycorrhizal associations in tropical rain forests with different disturbance regimes in South Cameroon

    OpenAIRE

    Onguene, N.A.

    2000-01-01

    The present study documents the occurrence of mycorrhizal associations in the rain forests of south Cameroon. All species investigated are mycorrhizal. Most timber species form arbuscular mycorrhiza, but some timber species, which usually occur in clumps, form ectomycorrhiza. Species diversity of ectomycorrhizal fungi in the undisturbed rain forest is substantial, with more than 125 species having been recorded. Inoculum potential of arbuscular mycorrhizal and ectomycorrhizal fungi is high in...

  7. Prevalence and determinants of cigarette smoking among college students: a cross-sectional study in Douala, Cameroon

    OpenAIRE

    Mbatchou Ngahane, Bertrand Hugo; Atangana Ekobo, Huguette; Kuaban, Christopher

    2015-01-01

    Background Tobacco is the most important avoidable risk for non communicable diseases. While tobacco consumption is stable or declining in developed countries, it is increasing in the developing world with a rate of 3.4 % per annum. The objective of this study was to estimate the prevalence and factors associated with cigarette smoking among college students. Methods A cross-sectional study was conducted from December 2012 to April 2013 in secondary schools in Douala, Cameroon. A self-adminis...

  8. The Effect of Short Rotation Desmodium distortum Planted Fallow on the Productivity of Ultisols in Centre Cameroon

    OpenAIRE

    Nguimgo, BAK.; Yemefack, M.; Kaho, F.; Zonkeng, CG.

    2004-01-01

    In order to investigate the effect of short rotation Desmodium distortum planted fallow on maize grain yield and soil properties, an experiment was conducted over four consecutive years (1995-1998) at two locations (Minkoameyos in the humid forest zone and Ntui in the forest-savannah transition zone) in Centre Cameroon. The experimental design for each year was made of four replications and three treatments: i) Natural Fallow used as control (NF), ii) Desmodium Fallow (DF) and iii) Soybean (G...

  9. SMALL Savannah: an information system for the integrated analysis of land use change in the Far North of Cameroon

    OpenAIRE

    Fotsing, Eric

    2009-01-01

    SMALL Savannah is an Environmental Information System designed for the integrated analysis and sustainable land management in the savannas region of the Far North of Cameroon. This system combines an observation and spatial analysis module for the representation of phenomena from various geographic data sources, with a module for the explanation and prediction of land use pattern and changes, and a dynamic modelling and simulation module for the exploration of possible land use change traject...

  10. Phenotypic Diversity Analysis of Oil Palm (Elaeis guineensis Jacq.) Germplasm Cameroon Origin Based on Vegetative and Physiologic Characteristic

    OpenAIRE

    Lubis, Mahmud Irfan; Putri, Lollie Agustina P.; Purba, Abdul Razak

    2016-01-01

    Forty seven accessions as a part of of oil palm germplasm Cameroon Origin is planted at Adolina, an estate of PT Perkebunan Nusantara IV were evaluated for the variability based on their early vegetative and physiology characteristics. Mean data from these accessions were analysed by Multivarite Analysis consist of Principal Component Analysis (PCA), revealing their variability and distribution. Results demonstrated that principal component analysis obtained two main components to contribute ...

  11. Assessment of Cane Yields on Well-drained Ferralsols in the Sugar-cane Estate of Central Cameroon

    OpenAIRE

    Van RANST, E.; Debaveye, J.; Mahop, F.

    1999-01-01

    The potential yields of irrigated and of rainfed sugar-cane on three ferrallitic soil series, well represented in the Nkoteng sugar-cane estate of Central Cameroon, are estimated following different methods. The potential yield of irrigated sugar-cane is estimated from the total maximum evapotranspiration during the crop cycle. The potential yield of rainfed sugar-cane is estimated following two methods for the establishment of a water balance and for the determination of a yield reduction as...

  12. Absence of Ornithodoros moubata, the vector of African swine fever virus, from the main pig producing area of Cameroon.

    Science.gov (United States)

    Ekue, N F; Wilkinson, P J

    1990-05-01

    No evidence for the presence of soft ticks of the Ornithodoros moubata complex was found during a survey of African swine fever carried out between 1985 and 1988 in the West Province and southern parts of the North West and South West Provinces of Cameroon. The survey consisted of interviews of veterinary assistants and farmers, distribution of a questionnaire and tick searches both manually and with carbon dioxide traps. The absence of warthogs (Phacochoerus aethiopicus) from these areas was also recorded. PMID:2371751

  13. Challenging Patriarchy: Trade, outward migration and the internationalization of Commercial sex among Bayang and Ejagham women in Southwest Cameroon

    OpenAIRE

    Ngambouk Vitalis Pemunta

    2011-01-01

    This paper documents the specific local and global socio-economic forces that led to the outward migration of Bayang and Ejagham women to work as commercial sex workers on the Cameroon-Nigeria border regions in the 1980s and 1990s. It demonstrates that these women’s personal accumulation strategies are adaptative- drawing on time and space specific modes of capitalist accumulation and kinship systems of power. The intertwined nature of these forms of accumulation demonstrate that patriarchal ...

  14. Volcanic Alert System (VAS) developed during the (2011-2013) El Hierro (Canary Islands) volcanic process

    Science.gov (United States)

    Ortiz, Ramon; Berrocoso, Manuel; Marrero, Jose Manuel; Fernandez-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Garcia, Alicia

    2014-05-01

    In volcanic areas with long repose periods (as El Hierro), recently installed monitoring networks offer no instrumental record of past eruptions nor experience in handling a volcanic crisis. Both conditions, uncertainty and inexperience, contribute to make the communication of hazard more difficult. In fact, in the initial phases of the unrest at El Hierro, the perception of volcanic risk was somewhat distorted, as even relatively low volcanic hazards caused a high political impact. The need of a Volcanic Alert System became then evident. In general, the Volcanic Alert System is comprised of the monitoring network, the software tools for the analysis of the observables, the management of the Volcanic Activity Level, and the assessment of the threat. The Volcanic Alert System presented here places special emphasis on phenomena associated to moderate eruptions, as well as on volcano-tectonic earthquakes and landslides, which in some cases, as in El Hierro, may be more destructive than an eruption itself. As part of the Volcanic Alert System, we introduce here the Volcanic Activity Level which continuously applies a routine analysis of monitoring data (particularly seismic and deformation data) to detect data trend changes or monitoring network failures. The data trend changes are quantified according to the Failure Forecast Method (FFM). When data changes and/or malfunctions are detected, by an automated watchdog, warnings are automatically issued to the Monitoring Scientific Team. Changes in the data patterns are then translated by the Monitoring Scientific Team into a simple Volcanic Activity Level, that is easy to use and understand by the scientists and technicians in charge for the technical management of the unrest. The main feature of the Volcanic Activity Level is its objectivity, as it does not depend on expert opinions, which are left to the Scientific Committee, and its capabilities for early detection of precursors. As a consequence of the El Hierro

  15. Intraplate Harrat Volcanism and Neogene Evolution of the Lithosphere-Asthenosphere Boundary beneath Western Saudi Arabia

    Science.gov (United States)

    Kent, A. J.; Duncan, R. A.; Graham, D. W.; Al-Amri, A. M.; Alshalntoni, S. A.

    2015-12-01

    Continental extension is a fundamental plate tectonic process, and extensional environments are associated with significant production of basaltic magmas. Although tholeiitic magmatism produced by mantle decompression is common, dispersed, less voluminous and compositionally variable basaltic and related magmas also occur in association with continental extension. One of the most voluminous, best-preserved and least studied examples of the latter is the volcanic harrats of western Saudi Arabia. Uplift, crustal erosion and harrat volcanism occurred from ~15 Ma to recent over a considerable region of western Arabia. Volcanism trends north from the Red Sea along the Makkah-Madinah-Nafud (MMN) line as a number of discrete harrats, and geophysical evidence suggests this region is underlain by hot upwelling asthenosphere. Larger harrats occur along the central axis of the MMN line, with smaller fields on the periphery. We present initial results of an ongoing study of harrat volcanism, including more than 50 new 40Ar-39Ar ages together with geochemical and isotopic data. Magma storage and fractionation appears to have occurred at a range of crustal levels, including deep storage and transport sufficiently rapid to preserve a range of lithospheric and crustal xenoliths. Melting commenced within the garnet peridotite field, however modeling of REE element abundances suggest that considerable differences exist in the thickness of the overlying lithospheric lid. Thinner lithosphere (line, whereas harrats peripheral to the MMN line have thicker lithosphere (>60-80 km) and magmas result from lower degree melts. The observed variability can be explained by a process of progressively thinning lithosphere along the main axis of the MMN line, as a result of regional lithospheric extension and mantle decompression melting, coupled with northward asthenospheric flow from the Red Sea and/or Afar hot spot.

  16. Role of volcanism in climate and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, D.I.

    1981-01-01

    Several major episodes of Tertiary explosive volcanism coincided with sharply lowered temperature as inferred from oxygen-isotope composition of foraminiferal tests in deep-sea cores. At these times, fossil floras in the western interior recorded significant changes. Reductions in taxa that required warmth occurred early in the Paleogene. Later, taxa that demand ample summer rain were reduced during a progressive change reflecting growth of the subtropic high. Other ecosystem changes that appear to have responded to volcanically induced climatic modifications include tachytely in Equidae (12 to 10 m.y. B.P.), rapid evolution of grasses (7 to 5 m.y. B.P.), evolution of marine mammals, and plankton flucuations. Although Lake Cretaceous extinctions commenced as epeiric seas retreated, the pulses of sharply lowered temperature induced by explosive volcanism, together with widespread falls of volcanic ash, may have led to extinction of dinosaurs, ammonites, cycadeoids, and other Cretaceous taxa. earlier, as Pangaea was assembled, Permian extinctions resulted not only from the elimination of oceans, epeiric seas, and shorelines, and the spread of more-continental climates, bu also from the climatic effects of major pulses of global volcanism and Gondwana glaciation.

  17. Volcanic iodine monoxide observed from satellite

    Science.gov (United States)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2016-04-01

    Halogen species are injected into the atmosphere by volcanic eruptions. Previous studies have reported observations of chlorine and bromine oxides in volcanic plumes. These emissions have a significant impact on the chemistry within the plume as well as on upper troposphere and lower stratosphere composition, e.g. through ozone depletion. Volcanic halogen oxides have been observed from different platforms, from ground, aircraft and from satellite. The present study reports on satellite observations of iodine monoxide, IO, following the eruption of the Kasatochi volcano, Alaska, in August 2008. Satellite measurements from the SCIAMACHY sensor onboard ENVISAT are used. In addition, the volcanic IO plume is also retrieved from GOME-2 / MetOP-A measurements. Largest IO column amounts reach up to more than 4×1013 molec/cm2, the results from both instruments being consistent. The IO plume has a very similar shape as the BrO plume and is observed for several days following the eruption. The present observations are the first evidence that besides chlorine and bromine oxides also iodine oxides can be emitted by volcanic eruptions. This has important implications for atmospheric composition and background iodine levels. Together with the simultaneous observations of BrO and SO2, iodine monoxide columns can possibly provide insights into the composition of the magma.

  18. Volcanic effects on climate: revisiting the mechanisms

    Directory of Open Access Journals (Sweden)

    H.-F. Graf

    2007-03-01

    Full Text Available The characteristics of planetary wave energy propagation are being compared based on NCEP reanalysis data from 1958 to 2002 between boreal winters after strong volcanic eruptions, non-volcanic winters and episodes of strong polar vortex lasting at least 30 days. It shows that in the volcanically disturbed winters much more planetary wave energy is produced in the troposphere, passes through the lowermost stratosphere and enters the upper stratosphere than in any other times. This is contradicting earlier interpretations and model simulations. Possibly the observed El Ninos coinciding with the three significant eruptions in the second half of the 20th century contributed to the planetary wave energy. In order to produce the observed robust climate anomaly patterns in the lower troposphere, these planetary waves are suggested to be reflected near the stratopause instead of breaking. While a strong polar vortex is observed after volcanic eruptions in the stratosphere and in the troposphere, specific episodes of strong polar vortex regime exhibit much stronger anomalies and different dynamics. Hence it is suggested that the climate effects of volcanic eruptions are not being explained by the excitation of inherent zonal mean variability modes such as Strong Polar Vortex or Northern Annular Mode, but rather is another mode that possibly reflects upon the North Atlantic Oscillation.

  19. Volcanic effects on climate: revisiting the mechanisms

    Directory of Open Access Journals (Sweden)

    H.-F. Graf

    2007-08-01

    Full Text Available The characteristics of planetary wave energy propagation are being compared based on NCEP reanalysis data from 1958 to 2002 between boreal winters after strong volcanic eruptions, non-volcanic winters and episodes of strong polar vortex lasting at least 30 days. It shows that in the volcanically disturbed winters much more planetary wave energy is produced in the troposphere, passes through the lowermost stratosphere and enters the upper stratosphere than in any other times. This is contradicting earlier interpretations and model simulations. Possibly the observed El Ninos coinciding with the three significant eruptions in the second half of the 20th century contributed to the planetary wave energy. In order to produce the observed robust climate anomaly patterns in the lower troposphere, these planetary waves are suggested to be reflected near the stratopause instead of breaking. While a strong polar vortex is observed after volcanic eruptions in the stratosphere and in the troposphere, specific episodes of strong polar vortex regime exhibit much stronger anomalies and different dynamics. Hence it is suggested that the climate effects of volcanic eruptions are not being explained by the excitation of inherent zonal mean variability modes such as Strong Polar Vortex or Northern Annular Mode, but rather is another mode that possibly reflects upon the North Atlantic Oscillation.

  20. On the use of Web-based-GIS for managing and disseminating hazard and risk spatial information in volcanic areas

    Directory of Open Access Journals (Sweden)

    G. Le Cozannet

    2013-10-01

    Full Text Available In volcanic areas exposed to multiple geological hazards, the efficient interpretation of the increasing amount of geographical data is a challenging issue. Within the European MIAVITA project, we investigated to which extent WebGIS can facilitate this interpretation through the visualization of such complex hazard and risk database. This analysis was structured around (1 the development of a Web-based Geographical Information System (WebGIS and of an application for managing the geographical database, and (2 interactions with a group of hazard and risk analysts and managers, civil security officers, GIS analysts and system developers. We tested the system in the Mount Cameroon volcano, taking advantage of a complex hazard and risk geographical database collected previously. Key requirements here related to the need for a structured and flexible GIS-database and to manage user's privileges differently according to their profile and the status of the volcano. In addition, this study showed that it is important for such systems to manage different status for data, from data than can only be interpreted by experts (e.g. some complex remote sensing products to data that can be disseminated to any potential user (e.g. a regulatory hazard map. While the developed tool is able to provide users with enough flexibility to respond to the users' requirements, it is still necessary to own expertise in WebGIS to manage such tools in the long term in local volcano observatory. Nevertheless, this study shows that WebGIS-based systems can relatively easily integrate some most important working procedures of hazard and risk management in volcanic areas.

  1. National volcanic ash operations plan for aviation

    Science.gov (United States)

    ,; ,

    2007-01-01

    The National Aviation Weather Program Strategic Plan (1997) and the National Aviation Weather Initiatives (1999) both identified volcanic ash as a high-priority informational need to aviation services. The risk to aviation from airborne volcanic ash is known and includes degraded engine performance (including flameout), loss of visibility, failure of critical navigational and operational instruments, and, in the worse case, loss of life. The immediate costs for aircraft encountering a dense plume are potentially major—damages up to $80 million have occurred to a single aircraft. Aircraft encountering less dense volcanic ash clouds can incur longer-term costs due to increased maintenance of engines and external surfaces. The overall goal, as stated in the Initiatives, is to eliminate encounters with ash that could degrade the in-flight safety of aircrews and passengers and cause damage to the aircraft. This goal can be accomplished by improving the ability to detect, track, and forecast hazardous ash clouds and to provide adequate warnings to the aviation community on the present and future location of the cloud. To reach this goal, the National Aviation Weather Program established three objectives: (1) prevention of accidental encounters with hazardous clouds; (2) reduction of air traffic delays, diversions, or evasive actions when hazardous clouds are present; and (3) the development of a single, worldwide standard for exchange of information on airborne hazardous materials. To that end, over the last several years, based on numerous documents (including an OFCMsponsored comprehensive study on aviation training and an update of Aviation Weather Programs/Projects), user forums, and two International Conferences on Volcanic Ash and Aviation Safety (1992 and 2004), the Working Group for Volcanic Ash (WG/VA), under the OFCM-sponsored Committee for Aviation Services and Research, developed the National Volcanic Ash Operations Plan for Aviation and Support of the

  2. Measurement of radioactivity in volcanic products

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Jun

    1988-10-01

    Radioactivity in volcanic products was measured for obtaining new knowledge about volcano. A distribution map of /sup 2//sup 2//sup 8/Ra//sup 2//sup 2//sup 6/Ra in the volcanic products of Japanese Islands volcanic front was prepared. From the map, it was understood that only Izu-Mariana Arc was different from other series of vocanos. Concerning Volcano Sakurajima, /sup 2//sup 2//sup 2/Rn//sup 2//sup 2//sup 0/Rn ratio in the pumice produced by the eruption was measured for studying its change with days after creation. Regarding the lava of Miyake Island, change of /sup 2//sup 1//sup 4/Bi with time was measured. 3 figures.

  3. Surface Coatings on Lunar Volcanic Glasses

    Science.gov (United States)

    Wentworth, Susan J.; McKay, D. S.; Thomas,-Keprta, K. L.; Clemett, S. J.

    2007-01-01

    We are undertaking a detailed study of surface deposits on lunar volcanic glass beads. These tiny deposits formed by vapor condensation during cooling of the gases that drove the fire fountain eruptions responsible for the formation of the beads. Volcanic glass beads are present in most lunar soil samples in the returned lunar collection. The mare-composition beads formed as a result of fire-fountaining approx.3.4-3.7 Ga ago, within the age range of large-scale mare volcanism. Some samples from the Apollo 15 and Apollo 17 landing sites are enriched in volcanic spherules. Three major types of volcanic glass bead have been identified: Apollo 15 green glass, Apollo 17 orange glass, and Apollo 17 "black" glass. The Apollo 15 green glass has a primitive composition with low Ti. The high-Ti compositions of the orange and black glasses are essentially identical to each other but the black glasses are opaque because of quench crystallization. A poorly understood feature common to the Apollo 15 and 17 volcanic glasses is the presence of small deposits of unusual materials on their exterior surfaces. For example, early studies indicated that the Apollo 17 orange glasses had surface enrichments of In, Cd, Zn, Ga, Ge, Au, and Na, and possible Pb- and Zn-sulfides, but it was not possible to characterize the surface features in detail. Technological advances now permit us to examine such features in detail. Preliminary FE-TEM/X-ray studies of ultramicrotome sections of Apollo 15 green glass indicate that the surface deposits are heterogeneous and layered, with an inner layer consisting of Fe with minor S and an outer layer of Fe and no S, and scattered Zn enrichments. Layering in surface deposits has not been identified previously; it will be key to defining the history of lunar fire fountaining.

  4. Seismo-volcanic sources on Stromboli volcano

    Directory of Open Access Journals (Sweden)

    R. Luckett

    1996-06-01

    Full Text Available A detailed analysis of broadband seismic recordings leads to models of eruption mechanisms for Strombolian activity. The data used comprise signals from arrays of nine three-component seismometers and video recordings of visual eruptive activity with precise time reference. As a major tool particle motion analysis is used to locate the seismo-volcanic sources. Here, a surface correction is employed to account for the effects of the steep slopes of the volcanic edifice. After careful filtering of the data single seismic phases can be separated and linked to corresponding eruptive features.

  5. Volcanic Eruptions and Climate: Outstanding Research Issues

    Science.gov (United States)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  6. Tellurium in active volcanic environments: Preliminary results

    Science.gov (United States)

    Milazzo, Silvia; Calabrese, Sergio; D'Alessandro, Walter; Brusca, Lorenzo; Bellomo, Sergio; Parello, Francesco

    2014-05-01

    Tellurium is a toxic metalloid and, according to the Goldschmidt classification, a chalcophile element. In the last years its commercial importance has considerably increased because of its wide use in solar cells, thermoelectric and electronic devices of the last generation. Despite such large use, scientific knowledge about volcanogenic tellurium is very poor. Few previous authors report result of tellurium concentrations in volcanic plume, among with other trace metals. They recognize this element as volatile, concluding that volcanic gases and sulfur deposits are usually enriched with tellurium. Here, we present some results on tellurium concentrations in volcanic emissions (plume, fumaroles, ash leachates) and in environmental matrices (soils and plants) affected by volcanic emissions and/or deposition. Samples were collected at Etna and Vulcano (Italy), Turrialba (Costa Rica), Miyakejima, Aso, Asama (Japan), Mutnovsky (Kamchatka) at the crater rims by using common filtration techniques for aerosols (polytetrafluoroethylene filters). Filters were both eluted with Millipore water and acid microwave digested, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Volcanic ashes emitted during explosive events on Etna and Copahue (Argentina) were analyzed for tellurium bulk composition and after leaching experiments to evaluate the soluble fraction of tellurium. Soils and leaves of vegetation were also sampled close to active volcanic vents (Etna, Vulcano, Nisyros, Nyiragongo, Turrialba, Gorely and Masaya) and investigated for tellurium contents. Preliminary results showed very high enrichments of tellurium in volcanic emissions comparing with other volatile elements like mercury, arsenic, thallium and bismuth. This suggests a primary transport in the volatile phase, probably in gaseous form (as also suggested by recent studies) and/or as soluble salts (halides and/or sulfates) adsorbed on the surface of particulate particles and ashes. First

  7. Emplacement Scenarios for Volcanic Domes on Venus

    Science.gov (United States)

    Glaze, Lori S.; Baloga, Steve M.; Stofan, Ellen R.

    2012-01-01

    One key to understanding the history of resurfacing on Venus is better constraints on the emplacement timescales for the range of volcanic features visible on the surface. A figure shows a Magellan radar image and topography for a putative lava dome on Venus. 175 such domes have been identified with diameters ranging from 19 - 94 km, and estimated thicknesses as great as 4 km. These domes are thought to be volcanic in origin and to have formed by the flow of viscous fluid (i.e., lava) on the surface.

  8. Constraining the onset of flood volcanism in Isle of Skye Lava Field, British Paleogene Volcanic Province

    Science.gov (United States)

    Angkasa, Syahreza; Jerram, Dougal. A.; Svensen, Henrik; Millet, John M.; Taylor, Ross; Planke, Sverre

    2016-04-01

    In order to constrain eruption styles at the onset of flood volcanism, field observations were undertaken on basal sections of the Isle of Skye Lava Field, British Paleogene Volcanic Province. This study investigates three specific sections; Camus Ban, Neist Point and Soay Sound which sample a large area about 1500 km2 and can be used to help explain the variability in palaeo-environments at the onset of flood volcanism. Petrological analysis is coupled with petrophysical lab data and photogrammetry data to create detailed facies models for the different styles of initiating flood basalt volcanism. Photogrammetry is used to create Ortho-rectified 3D models which, along with photomontage images, allow detailed geological observations to be mapped spatially. Petrographic analyses are combined with petrophysical lab data to identify key textural variation, mineral compositions and physical properties of the volcanic rocks emplaced during the initial eruptions. Volcanism initiated with effusive eruptions in either subaerial or subaqueous environments resulting in tuff/hyaloclastite materials or lava flow facies lying directly on the older Mesozoic strata. Volcanic facies indicative of lava-water interactions vary significantly in thickness between different sections suggesting a strong accommodation space control on the style of volcanism. Camus Ban shows hyaloclastite deposits with a thickness of 25m, whereas the Soay Sound area has tuffaceous sediments of under 0.1m in thickness. Subaerial lavas overly these variable deposits in all studied areas. The flood basalt eruptions took place in mixed wet and dry environments with some significant locally developed water bodies (e.g. Camus Ban). More explosive eruptions were promoted in some cases by interaction of lavas with these water bodies and possibly by local interaction with water - saturated sediments. We record key examples of how palaeotopography imparts a primary control on the style of volcanism during the

  9. The volcanic response to deglaciation: Evidence from glaciated arcs and a reassessment of global eruption records

    Science.gov (United States)

    Watt, Sebastian F. L.; Pyle, David M.; Mather, Tamsin A.

    Several lines of evidence have previously been used to suggest that ice retreat after the last glacial maximum (LGM) resulted in regionally-increased levels of volcanic activity. It has been proposed that this increase in volcanism was globally significant, forming a substantial component of the post-glacial rise in atmospheric CO2, and thereby contributing to climatic warming. However, as yet there has been no detailed investigation of activity in glaciated volcanic arcs following the LGM. Arc volcanism accounts for 90% of present-day subaerial volcanic eruptions. It is therefore important to constrain the impact of deglaciation on arc volcanoes, to understand fully the nature and magnitude of global-scale relationships between volcanism and glaciation. The first part of this paper examines the post-glacial explosive eruption history of the Andean southern volcanic zone (SVZ), a typical arc system, with additional data from the Kamchatka and Cascade arcs. In all cases, eruption rates in the early post-glacial period do not exceed those at later times at a statistically significant level. In part, the recognition and quantification of what may be small (i.e. less than a factor of two) increases in eruption rate is hindered by the size of our datasets. These datasets are limited to eruptions larger than 0.1 km3, because deviations from power-law magnitude-frequency relationships indicate strong relative under-sampling at smaller eruption volumes. In the southern SVZ, where ice unloading was greatest, eruption frequency in the early post-glacial period is approximately twice that of the mid post-glacial period (although frequency increases again in the late post-glacial). A comparable pattern occurs in Kamchatka, but is not observed in the Cascade arc. The early post-glacial period also coincides with a small number of very large explosive eruptions from the most active volcanoes in the southern and central SVZ, consistent with enhanced ponding of magma during

  10. Ecological niche partitioning between Anopheles gambiae molecular forms in Cameroon: the ecological side of speciation

    Directory of Open Access Journals (Sweden)

    Fotsing Jean-Marie

    2009-05-01

    Full Text Available Abstract Background Speciation among members of the Anopheles gambiae complex is thought to be promoted by disruptive selection and ecological divergence acting on sets of adaptation genes protected from recombination by polymorphic paracentric chromosomal inversions. However, shared chromosomal polymorphisms between the M and S molecular forms of An. gambiae and insufficient information about their relationship with ecological divergence challenge this view. We used Geographic Information Systems, Ecological Niche Factor Analysis, and Bayesian multilocus genetic clustering to explore the nature and extent of ecological and chromosomal differentiation of M and S across all the biogeographic domains of Cameroon in Central Africa, in order to understand the role of chromosomal arrangements in ecological specialisation within and among molecular forms. Results Species distribution modelling with presence-only data revealed differences in the ecological niche of both molecular forms and the sibling species, An. arabiensis. The fundamental environmental envelope of the two molecular forms, however, overlapped to a large extent in the rainforest, where they occurred in sympatry. The S form had the greatest niche breadth of all three taxa, whereas An. arabiensis and the M form had the smallest niche overlap. Correspondence analysis of M and S karyotypes confirmed that molecular forms shared similar combinations of chromosomal inversion arrangements in response to the eco-climatic gradient defining the main biogeographic domains occurring across Cameroon. Savanna karyotypes of M and S, however, segregated along the smaller-scale environmental gradient defined by the second ordination axis. Population structure analysis identified three chromosomal clusters, each containing a mixture of M and S specimens. In both M and S, alternative karyotypes were segregating in contrasted environments, in agreement with a strong ecological adaptive value of

  11. Habitat suitability and ecological niche profile of major malaria vectors in Cameroon

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    Agbor Jean-Pierre

    2009-12-01

    Full Text Available Abstract Background Suitability of environmental conditions determines a species distribution in space and time. Understanding and modelling the ecological niche of mosquito disease vectors can, therefore, be a powerful predictor of the risk of exposure to the pathogens they transmit. In Africa, five anophelines are responsible for over 95% of total malaria transmission. However, detailed knowledge of the geographic distribution and ecological requirements of these species is to date still inadequate. Methods Indoor-resting mosquitoes were sampled from 386 villages covering the full range of ecological settings available in Cameroon, Central Africa. Using a predictive species distribution modeling approach based only on presence records, habitat suitability maps were constructed for the five major malaria vectors Anopheles gambiae, Anopheles funestus, Anopheles arabiensis, Anopheles nili and Anopheles moucheti. The influence of 17 climatic, topographic, and land use variables on mosquito geographic distribution was assessed by multivariate regression and ordination techniques. Results Twenty-four anopheline species were collected, of which 17 are known to transmit malaria in Africa. Ecological Niche Factor Analysis, Habitat Suitability modeling and Canonical Correspondence Analysis revealed marked differences among the five major malaria vector species, both in terms of ecological requirements and niche breadth. Eco-geographical variables (EGVs related to human activity had the highest impact on habitat suitability for the five major malaria vectors, with areas of low population density being of marginal or unsuitable habitat quality. Sunlight exposure, rainfall, evapo-transpiration, relative humidity, and wind speed were among the most discriminative EGVs separating "forest" from "savanna" species. Conclusions The distribution of major malaria vectors in Cameroon is strongly affected by the impact of humans on the environment, with variables

  12. Addressing Health Workforce Distribution Concerns: A Discrete Choice Experiment to Develop Rural Retention Strategies in Cameroon

    Directory of Open Access Journals (Sweden)

    Paul Jacob Robyn

    2015-03-01

    Full Text Available Background Nearly every nation in the world faces shortages of health workers in remote areas. Cameroon is no exception to this. The Ministry of Public Health (MoPH is currently considering several rural retention strategies to motivate qualified health personnel to practice in remote rural areas. Methods To better calibrate these mechanisms and to develop evidence-based retention strategies that are attractive and motivating to health workers, a Discrete Choice Experiment (DCE was conducted to examine what job attributes are most attractive and important to health workers when considering postings in remote areas. The study was carried out between July and August 2012 among 351 medical students, nursing students and health workers in Cameroon. Mixed logit models were used to analyze the data. Results Among medical and nursing students a rural retention bonus of 75% of base salary (aOR= 8.27, 95% CI: 5.28-12.96, P< 0.001 and improved health facility infrastructure (aOR= 3.54, 95% CI: 2.73-4.58 respectively were the attributes with the largest effect sizes. Among medical doctors and nurse aides, a rural retention bonus of 75% of base salary was the attribute with the largest effect size (medical doctors aOR= 5.60, 95% CI: 4.12-7.61, P< 0.001; nurse aides aOR= 4.29, 95% CI: 3.11-5.93, P< 0.001. On the other hand, improved health facility infrastructure (aOR= 3.56, 95% CI: 2.75-4.60, P< 0.001, was the attribute with the largest effect size among the state registered nurses surveyed. Willingness-to-Pay (WTP estimates were generated for each health worker cadre for all the attributes. Preference impact measurements were also estimated to identify combination of incentives that health workers would find most attractive. Conclusion Based on these findings, the study recommends the introduction of a system of substantial monetary bonuses for rural service along with ensuring adequate and functional equipment and uninterrupted supplies. By focusing on

  13. Proportion of extended-spectrum ß-lactamase-producing Enterobacteriaceae in community setting in Ngaoundere, Cameroon

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    Lonchel Carine

    2012-03-01

    Full Text Available Abstract Background There is no information regarding the resistance mechanisms of extended-spectrum ß-lactamase (ESBL-producing Enterobacteriaceae in community setting in Cameroon. The current study aimed to determine the proportion of ESBLs in Enterobacteriaceae isolated in the community and to analyse some risk factors associated with ESBL carriage. Methods Faecal samples were collected from 208 different outpatients and 150 healthy student volunteers between 3 January and 3 April 2009. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production by the double-disk synergy test. Presumptive ESBL-producing isolates with positive synergy test were identified by Mass Spectrometry using the BioTyper MALDI-TOF. For such ESBL positive isolates, antibiotic susceptibility was determined by the Vitek 2 system. PCR and sequencing were performed for the detection of different types of ESBL genes in presumptive ESBL-producing isolates. Statistical methods were used for the univariate calculation of risk factors. Results During the study period, a total of 358 faecal samples were analysed; 58 of such samples (16% showed an ESBL phenotype and were confirmed by PCR. The proportion of ESBL producers in faecal carriage was statistically different between outpatients and student volunteers (23.1% vs. 6.7%: p p Escherichia coli was the species most frequently isolated among the ESBL producers in outpatients (66.7% and student volunteers (90%. Isolates showed additional resistance to gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole but none of them was resistant to temocillin, amikacin or meropenem. Most of the strains (97% produced a CTX-M group 1 enzymes [CTX-M-15 (98% or CTX-M-1 (2%] and the remaining strains produced SHV-12 enzyme (3%. Conclusions The use of drugs such as amoxicillin, ciprofloxacin and trimethoprim/sulfamethoxazole does not seem appropriate for empirical treatment because of emerging

  14. Plate Tectonic Setting and Eruptive Characteristics of the K—rich Volcanic Belt in HeilingJiang Province,Northeast China

    Institute of Scientific and Technical Information of China (English)

    邱家骧; 吴志勤; 等

    1990-01-01

    Various lines of geological,geophysical and geochemical evidence indicate that the K-rich volcanic belt in Northeast China as represented by the volcanic groups at Wudalianchi,Erkeshan and Kelo was developed,in terms of plate tectonics,in a rift valley system within the continental plate,The volcanic material includes effusive lavas and explosive pyroclastics whose characteristics and flowing/accumulation mechanisms were studied in detail,The distribution of pyroclastics shows that the eruption is of Strombolian type with increasing intensity towards the late stages.

  15. Treatment failure in a typhoid patient infected with nalidixic acid resistant S. enterica serovar Typhi with reduced susceptibility to Ciprofloxacin: a case report from Cameroon

    Directory of Open Access Journals (Sweden)

    Asonganyi Etienne DN

    2005-06-01

    Full Text Available Abstract Background Fluoroquinolones or third generation cephalosporins are the drugs of choice for the treatment of typhoid fever. Treatment failure with fluoroquinolones has been reported in Asia and Europe. We report a case of ciprofloxacin treatment failure in typhoid fever in Cameroon. Case presentation A 29-year-old female patient with suspected typhoid fever from Kumba, Cameroon, yielded growth of Salmonella enterica serovar Typhi in blood culture. The isolate was resistant to nalidixic acid but sensitive to ciprofloxacin by disc diffusion test. However, the patient did not respond to treatment with ciprofloxacin, although the isolate was apparently susceptible to ciprofloxacin. Conclusion Treatment failure with ciprofloxacin in our case indicates the presence of nalidixic acid resistant S. enterica serovar Typhi (NARST with reduced susceptibility to ciprofloxacin in Cameroon (Central Africa.

  16. High gene flow and outcrossing within populations of two cryptic fungal pathogens on a native and non-native host in Cameroon.

    Science.gov (United States)

    Begoude Boyogueno, Aime Didier; Slippers, Bernard; Perez, Guillermo; Wingfield, Michael J; Roux, Jolanda

    2012-03-01

    In this study, we determined the genetic diversity of 126 isolates representing both Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae, collected from Theobroma cacao and Terminalia spp. in Cameroon, using simple sequence repeat (SSR) markers. SSR alleles showed clear genetic distinction between L. theobromae and L. pseudotheobromae, supporting their earlier separation as sister species. Both L. theobromae and L. pseudotheobromae populations from Cameroon had high levels of gene diversity, moderate degrees of genotypic diversity, and high levels of gene flow between isolates from T. cacao and Terminalia spp. There was no evidence for geographic substructure in these populations across the region studied, and the SSR alleles were randomly associated in both species, suggesting outcrossing. The significant levels of aggressiveness, evolutionary potential represented by high levels of diversity, outcrossing and gene flow between geographically and host defined populations, identify these fungi as high-risk pathogens for their native and non-native hosts in Cameroon. PMID:22385617

  17. Monitoring and forecasting Etna volcanic plumes

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    S. Scollo

    2009-09-01

    Full Text Available In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i downloading weather forecast data from meteorological mesoscale models; ii running models of tephra dispersal, iii plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  18. Monogenetic volcanism: personal views and discussion

    Science.gov (United States)

    Németh, K.; Kereszturi, G.

    2015-11-01

    Monogenetic volcanism produces small-volume volcanoes with a wide range of eruptive styles, lithological features and geomorphic architectures. They are classified as spatter cones, scoria (or cinder) cones, tuff rings, maars (maar-diatremes) and tuff cones based on the magma/water ratio, dominant eruption styles and their typical surface morphotypes. The common interplay between internal, such as the physical-chemical characteristics of magma, and external parameters, such as groundwater flow, substrate characteristics or topography, plays an important role in creating small-volume volcanoes with diverse architectures, which can give the impression of complexity and of similarities to large-volume polygenetic volcanoes. In spite of this volcanic facies complexity, we defend the term "monogenetic volcano" and highlight the term's value, especially to express volcano morphotypes. This study defines a monogenetic volcano, a volcanic edifice with a small cumulative volume (typically ≤1 km3) that has been built up by one continuous, or many discontinuous, small eruptions fed from one or multiple magma batches. This definition provides a reasonable explanation of the recently recognized chemical diversities of this type of volcanism.

  19. Monitoring and forecasting Etna volcanic plumes

    Science.gov (United States)

    Scollo, S.; Prestifilippo, M.; Spata, G.; D'Agostino, M.; Coltelli, M.

    2009-09-01

    In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i) downloading weather forecast data from meteorological mesoscale models; ii) running models of tephra dispersal, iii) plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv) publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  20. Organic Entrainment and Preservation in Volcanic Glasses

    Science.gov (United States)

    Wilhelm, Mary Beth; Ojha, Lujendra; Brunner, Anna E.; Dufek, Josef D.; Wray, James Joseph

    2014-01-01

    Unaltered pyroclastic deposits have previously been deemed to have "low" potential for the formation, concentration and preservation of organic material on the Martian surface. Yet volcanic glasses that have solidified very quickly after an eruption may be good candidates for containment and preservation of refractory organic material that existed in a biologic system pre-eruption due to their impermeability and ability to attenuate UV radiation. Analysis using NanoSIMS of volcanic glass could then be performed to both deduce carbon isotope ratios that indicate biologic origin and confirm entrainment during eruption. Terrestrial contamination is one of the biggest barriers to definitive Martian organic identification in soil and rock samples. While there is a greater potential to concentrate organics in sedimentary strata, volcanic glasses may better encapsulate and preserve organics over long time scales, and are widespread on Mars. If volcanic glass from many sites on Earth could be shown to contain biologically derived organics from the original environment, there could be significant implications for the search for biomarkers in ancient Martian environments.

  1. Implications of volcanic erratics in Quaternary deposits of North Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby; Larsen, Ole

    1982-01-01

    Erratic boulders, petrographically similar to the volcanics exposed around Kap Washington, are found on islands and along the coast much further to the east. Isotopic measurements on two such boulders show that these volcanic rocks are of the same age as the Kap Washington volcanics. The regional...

  2. Volcanic Ash Transport and Dispersion Forecasting

    Science.gov (United States)

    Servranckx, R.; Stunder, B.

    2006-12-01

    Volcanic ash transport and dispersion models (VATDM) have been used operationally since the mid 1990's by the International Civil Aviation Organization (ICAO) designated Volcanic Ash Advisory Centers (VAAC) to provide ash forecast guidance. Over the years, significant improvements in the detection and prediction of airborne volcanic ash have been realized thanks to improved models, increases in computing power, 24-hr real time monitoring by VAACs / Meteorological Watch Offices and close coordination with Volcano Observatories around the world. Yet, predicting accurately the spatial and temporal structures of airborne volcanic ash and the deposition at the earth's surface remains a difficult and challenging problem. The forecasting problem is influenced by 3 main components. The first one (ERUPTION SOURCE PARAMETERS) comprises all non-meteorological parameters that characterize a specific eruption or volcanic ash cloud. For example, the volume / mass of ash released in the atmosphere, the duration of the eruption, the altitude and distribution of the ash cloud, the particle size distribution, etc. The second component (METEOROLOGY) includes all meteorological parameters (wind, moisture, stability, etc.) that are calculated by Numerical Weather Prediction models and that serve as input to the VATDM. The third component (TRANSPORT AND DISPERSION) combines input from the other 2 components through the use of VATDM to transport and disperse airborne volcanic ash in the atmosphere as well as depositing it at the surface though various removal mechanisms. Any weakness in one of the components may adversely affect the accuracy of the forecast. In a real-time, operational response context such as exists at the VAACs, the rapid delivery of the modeling results puts some constraints on model resolution and computing time. Efforts are ongoing to evaluate the reliability of VATDM forecasts though the use of various methods, including ensemble techniques. Remote sensing data

  3. Volcanic Plume Chemistry: Models, Observations and Impacts

    Science.gov (United States)

    Roberts, Tjarda; Martin, Robert; Oppenheimer, Clive; Griffiths, Paul; Braban, Christine; Cox, Tony; Jones, Rod; Durant, Adam; Kelly, Peter

    2010-05-01

    Volcanic plumes are highly chemically reactive; both in the hot, near-vent plume, and also at ambient temperatures in the downwind plume, as the volcanic gases and aerosol disperse into the background atmosphere. In particular, DOAS (Differential Optical Absortpion Spectroscopy) observations have identified BrO (Bromine Monoxide) in several volcanic plumes degassing into the troposphere. These observations are explained by rapid in-plume autocatalytic BrO-chemistry that occurs whilst the plume disperses, enabling oxidants such as ozone from background air to mix with the acid gases and aerosol. Computer modelling tools have recently been developed to interpret the observed BrO and predict that substantial ozone depletion occurs downwind. Alongside these modelling developments, advances in in-situ and remote sensing techniques have also improved our observational understanding of volcanic plumes. We present simulations using the model, PlumeChem, that predict the spatial distribution of gases in volcanic plumes, including formation of reactive halogens BrO, ClO and OClO that are enhanced nearer the plume edges, and depletion of ozone within the plume core. The simulations also show that in-plume chemistry rapidly converts NOx into nitric acid, providing a mechanism to explain observed elevated in-plume HNO3. This highlights the importance of coupled BrO-NOx chemistry, both for BrO-formation and as a production mechanism for HNO3 in BrO-influenced regions of the atmosphere. Studies of coupled halogen-H2S-chemistry are consistent with in-situ Alphasense electrochemical sensor observations of H2S at a range of volcanoes, and only predict H2S-depletion if Cl is additionally elevated. Initial studies regarding the transformations of mercury within volcanic plumes suggest that significant in-plume conversion of Hg0 to Hg2+ can occur in the downwind plume. Such Hg2+ may impact downwind ecology through enhanced Hg-deposition, and causing enhanced biological uptake of

  4. Shallow groundwater from the far north of Cameroon (southern Lake Chad): revisiting a 20 years old survey of hydrochemistry and stable isotopes

    Science.gov (United States)

    Ketchemen-Tandia, Beatrice; Mohammad, Bello; Fouepe, Alain; Ngo Boum, Suzanne; Nlend, Bertil; Garel, Emilie; Celle-Jeanton, Helene; Huneau, Frederic

    2016-04-01

    Two field hydrogeological investigation surveys were conducted in 1992 and 2013 using hydrochemistry and isotope techniques in the far north part of Cameroon which corresponds to the southern part of Lake Chad basin. All of these data relate to groundwater and surface water which were collected at the same places to potentially reveal any temporal variation in the chemical and isotopic characteristics of the water resources. Groundwater show mainly a Ca-HCO3 water type but CaMg-Cl and Na-HCO3 water types can also be found. The groundwater chemistry is resulting from many processes including pure silicate weathering and cation exchange. It is found that the nitrate content after 20 years has increased by an average factor of 6. These high concentrations in nitrate (up to 400 mg/l) are related to local anthropogenic activities and to the very bad conditions of maintaining of wells and boreholes. This pollution is also correlated to the population growth over the past two decades in the region. The isotopic content of groundwater is ranging from -6.87‰ to -0.32‰ for δ18O in 2013 and from -6.03‰ to +0.25‰ in 1992 without noticeable evolution through time. The conventional δD-δ18O diagram indicates that the groundwater has a meteoric origin more or less influenced by evaporation processes. Different processes involving different water sources were highlighted: (i) groundwater which has been affected by evaporation or in communication with evaporated surface waters; (ii) groundwater which is very close to the Global Meteoric Water Line and corresponding to a recent and direct recharge from precipitation; (iii) groundwater which is more depleted corresponding to a mixing between shallow and deep groundwater. This research is partly supported by the RAF7012and RAF7011 project from IAEA.

  5. HYDROLOGIC MODELLING OF KATSINA-ALA RIVER BASIN: AN EMERGING SCENARIO FROM LAKE NYOS THREAT

    OpenAIRE

    Akinyede, J.O.; R. Babamaaji; M. Vaatough; K. A. Adepoju

    2012-01-01

    Understanding the hydrologic system surrounding crater lakes is of great importance for prevention of flooding damages, conservation of ecological environment, and assessment of socio-economic impact of dam failure on the civilians in the downstream regions. Lake Nyos is a crater lake formed by volcanic activities at the Oku volcanic field on the Cameroon Volcanic Line. It is a freshwater lake with a maximum depth of 200 meter. In 1986, a limnic eruption at the lake emitted 1.6 million tonnes...

  6. Holocene explosive volcanism of the Jan Mayen (island) volcanic province, North-Atlantic

    Science.gov (United States)

    Gjerløw, Eirik; Haflidason, H.; Pedersen, R. B.

    2016-07-01

    The volcanic island Jan Mayen, located in the Norwegian-Greenland Sea, hosts the active stratovolcano of Beerenberg, the northernmost active subaerial volcano in the world. At least five eruptions are known from the island following its discovery in the 17th century, but its eruptive history prior to this is basically unknown. In this paper two sediment cores retrieved close to Jan Mayen have been studied in detail to shed light on the Holocene history of explosive volcanism from the Jan Mayen volcanic province. Horizons with elevated tephra concentrations were identified and tephra from these was analysed to determine major element chemistry of the tephra. The tephra chemistry was used to provide a link between the two cores and the land based tephra records from Jan Mayen Island. We managed to link two well-developed tephra peaks in the cores by their geochemical composition and age to Jan Mayen. One of these peaks represents the 1732 AD eruption of Eggøya while the other peak represents a previously undescribed eruption dated to around 10.3 ka BP. Two less prominent tephra peaks, one in each core, dated to approximately 2.3 and 3.0 ka BP, also have a distinct geochemical character linking them to Jan Mayen volcanism. However, the most prominent tephra layer in the cores located close to Jan Mayen and numerous other cores along the Jan Mayen ridge is the 12.1 ka BP Vedde Ash originating from the Iceland volcanic province. We find that the Holocene volcanism on Jan Mayen is much less explosive than volcanism in Iceland, and propose that either low amounts of explosive volcanic activity from the summit region of Beerenberg or small to absent glacier cover on Beerenberg is responsible for this.

  7. Sustaining mother tongue medium education: An inter-community self-help framework in Cameroon

    Science.gov (United States)

    Chiatoh, Blasius A.

    2011-12-01

    Advocating mother tongue education implies recognising the centrality of linguistic and cultural diversity in quality and accessible education planning and delivery. In minority linguistic settings, this need becomes particularly urgent. Decades of exclusive promotion of foreign languages have rendered the educational system incapable of guaranteeing maximum quality, accessibility and equity. Also, due to long periods of marginalisation and disempowerment, most indigenous communities are unable to undertake viable self-reliant educational initiatives. As a result, planning and management of education is not adapted to the needs and realities of target populations. What such an educational approach has succeeded in achieving is to cultivate a culture of near-total dependence and consumerism. In minority language situations where mother tongue education is still primarily in the hands of private institutions and individuals, successful planning also means influencing the perceptions and attitudes of indigenous people and systematically integrating them into the educational process. This paper discusses grass-roots mother tongue education in Cameroon. It focuses on the inter-community self-help initiative as a local response framework and argues that this initiative is a strong indication of the desire of communities to learn and promote learning in their own languages.

  8. An economic comparison of typical dairy farming systems in South Africa, Morocco, Uganda and Cameroon.

    Science.gov (United States)

    Ndambi, Oghaiki Asaah; Hemme, Torsten

    2009-08-01

    Population growth, urbanisation and increased per capita milk consumption are main reasons for recent increasing milk demand in Africa. Due to globalisation, it is important to know how competitive various production systems are, especially as most governments promote local production and disfavour dairy imports. The TIPI-CAL (Technology Impact, Policy Impact Calculations model) was used to analyse and compare costs and returns of predominant dairy farming systems in South Africa, Morocco, Uganda and Cameroon. Results show that, as farms grew larger in size, family resources (especially land and labour) became insufficient and there was need for their acquisition from external sources. Though extensive dairy farming systems had the lowest cost of milk production (<20 US-$ per 100 kg milk), their input productivities and milk yields were lower, leading to very low net cash returns from dairying. Large intensive farms in South Africa had relatively low costs (<30 US-$ per 100 kg milk) and a high Return on Investment (ROI) due to a higher efficiency of input utilisation. It was concluded that, intensification of dairy farming and simultaneously increasing the scale of production will greatly increase productivity of farm inputs, thus recommended for development of the dairy sector in African countries. PMID:19082756

  9. Novel highly divergent reassortant bat rotaviruses in Cameroon, without evidence of zoonosis

    Science.gov (United States)

    Yinda, Claude Kwe; Zeller, Mark; Conceição-Neto, Nádia; Maes, Piet; Deboutte, Ward; Beller, Leen; Heylen, Elisabeth; Ghogomu, Stephen Mbigha; Van Ranst, Marc; Matthijnssens, Jelle

    2016-01-01

    Bats are an important reservoir for zoonotic viruses. To date, only three RVA strains have been reported in bats in Kenya and China. In the current study we investigated the genetic diversity of RVAs in fecal samples from 87 straw-colored fruit bats living in close contact with humans in Cameroon using viral metagenomics. Five (near) complete RVA genomes were obtained. A single RVA strain showed a partial relationship with the Kenyan bat RVA strain, whereas the other strains were completely novel. Only the VP7 and VP4 genes showed significant variability, indicating the occurrence of frequent reassortment events. Comparing these bat RVA strains with currently used human RVA screening primers indicated that most of the novel VP7 and VP4 segments would not be detected in routine epidemiological screening studies. Therefore, novel consensus screening primers were developed and used to screen samples from infants with gastroenteritis living in close proximity with the studied bat population. Although RVA infections were identified in 36% of the infants, there was no evidence of zoonosis. This study identified multiple novel bat RVA strains, but further epidemiological studies in humans will have to assess if these viruses have the potential to cause gastroenteritis in humans. PMID:27666390

  10. Assessment of gastrointestinal parasites in wild chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon.

    Science.gov (United States)

    Drakulovski, Pascal; Bertout, Sébastien; Locatelli, Sabrina; Butel, Christelle; Pion, Sébastien; Mpoudi-Ngole, Eitel; Delaporte, Eric; Peeters, Martine; Mallié, Michèle

    2014-07-01

    We tested 114 faecal samples from wild simian immunodeficiency virus (SIV)-positive (n = 43) and SIV-negative (n = 71) chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon for the presence of gastrointestinal parasites by direct smear. We observed cysts from different protozoa (Entamoeba coli and Entamoeba histolytica / Entamoeba dispar, Endolimax nana, Iodamoeba butschlii, Chilomastix mesnili, Balantidium coli and Blastocystis cells) and trophozoites from Troglodytella abrassarti and Balantidium coli. Eggs from different helminths (strongylids, Ascaris lumbricoides, Abbreviata caucasica, Trichuris sp., Capillaria sp., Enterobius anthropopeci, Bertiella sp., Hymenolepis diminuta and an undetermined fluke) were also observed. Finally, we observed eggs that could not be properly identified and classified. We did not observe any differences between the SIV+ and SIV- samples except for the unidentified eggs. The studied chimpanzees were highly parasitised by strongylid (85.1% of prevalence), Troglodytella (43.8%) and Blastocystis (2.9%), and the frequency of the other parasites ranged from 0.9 to 8.8%. These high levels of parasite infections could represent an additional burden in a population where there is a high rate of the SIV virus in circulation. PMID:24781023

  11. Muddying the Waters: A New Area of Concern for Drinking Water Contamination in Cameroon

    Directory of Open Access Journals (Sweden)

    Jessica M. Healy Profitós

    2014-11-01

    Full Text Available In urban Maroua, Cameroon, improved drinking water sources are available to a large majority of the population, yet this water is frequently distributed through informal distribution systems and stored in home containers (canaries, leaving it vulnerable to contamination. We assessed where contamination occurs within the distribution system, determined potential sources of environmental contamination, and investigated potential pathogens. Gastrointestinal health status (785 individuals was collected via health surveys. Drinking water samples were collected from drinking water sources and canaries. Escherichia coli and total coliform levels were evaluated and molecular detection was performed to measure human-associated faecal marker, HF183; tetracycline-resistance gene, tetQ; Campylobacter spp.; and Staphylococcus aureus. Statistical analyses were performed to evaluate the relationship between microbial contamination and gastrointestinal illness. Canari samples had higher levels of contamination than source samples. HF183 and tetQ were detected in home and source samples. An inverse relationship was found between tetQ and E. coli. Presence of tetQ with lower E. coli levels increased the odds of reported diarrhoeal illness than E. coli levels alone. Further work is warranted to better assess the relationship between antimicrobial-resistant bacteria and other pathogens in micro-ecosystems within canaries and this relationship’s impact on drinking water quality.

  12. [Epidemiologic study of dracunculosis in the Podokwos of the Mandara mountains (northern Cameroon)].

    Science.gov (United States)

    Issoufa, H; Monekosso, G; Ripert, C

    1979-01-01

    The purpose of the present work is the study of the epidemiological aspects of dracontiasis in an endemic area in Cameroon. The study was undertaken in the central Podokwo settlement in Mora subdivision. It is a mountainous area with a climate characterized by a long dry season, from October to mid-May, and a short rainy season. Two seasonal, streams run across the settlement. The water supply of the community is ensured throughout the year by two well built wells. During the rainy season, shallow unprotected wells are the water sources of about 80% of the inhabitants. Among the 944 subjects studied in our sample, 251 had the disease, corresponding to a prevalence of 26 6%. There is no significant difference between both sexes in the prevalence of the disease in our study. The age group 13-26 years is most affected. The worm load varies from 1 to 5, averagely 1.5. As to the localization of the worms in the body, in 92.7% of cases the worms is located in the lower limbs, the feet alone representing up to 46.8%. Less common sites of localization are the head, the breast, the external genitalia. The maximum rate of infestation is observed between August and September. Desinfection of wells with chemicals would be recommended during this period of time.

  13. An Ethnographic Study of Diabetes: Implications for the Application of Patient Centred Care in Cameroon

    Directory of Open Access Journals (Sweden)

    Paschal Kum Awah

    2014-01-01

    Full Text Available Participant observation was conducted to explore the understanding of diabetes and examine the implications of these understandings for providing effective patient centered care in Cameroon. Ethnographic techniques—content and thematic analysis—were used to analyze the data collected from diverse techniques. Most participants distinguished “natural,” “supernatural,” and “man-made” causes of diabetes. Such aetiologies guided the behaviour and approaches adopted for treatment and helped explain why biomedical and traditional healing frameworks could so readily be used in tandem. Clinical encounters are often only one small part of the diabetes care process, alongside recourse to traditional medicine. With rituals, agents causing diabetes are apparently more convincingly explained as powerful reinforcement and a cure promised in traditional medicine. Though it seems “irrational” and dangerous to clinics when patients alternate between therapeutic regimes or pursue both simultaneously, it seems perfectly rational and beneficial to patients and beyond. So long as biomedical practitioners fail to recognize that their patients will probably also have recourse to traditional medicine, they and their services may compound the problems they face for patients to discuss openly how they have been managing their condition.

  14. History of partnership between agro-industries and oil palm smallholders in Cameroon

    Directory of Open Access Journals (Sweden)

    Nkongho Raymond N.

    2015-05-01

    Full Text Available The present article explores the origin and changes in partnership agreements established between agro-industries and oil palm smallholders in Cameroon. The different forms of partnership which have existed over the years in the oil palm sector until now are assessed, notably the FONADER-sponsored smallholder scheme (1978 to 1991 and more recently the Afriland First Bank sponsored villagisation project of Socapalm Eseka (2007/2008 to present. Special attention is given to the factors and conditions that have influenced the outcomes of these partnerships, specifically the failure of the FONADER-sponsored smallholder scheme. The authors conclude that with the current absence of steady support from the government to oil palm smallholders, especially after the implementation of the structural adjustment plans, private partnership schemes between agro-industries and oil palm smallholders could be highly profitable for both stakeholders. Such partnerships can foster social cohesion and limit further encroachment of agro-industries into the primary forest, provided such partnership agreements are carefully planned and adequately implemented.

  15. [Anopheles gambiae, major malaria vector in Logbessou, a peri-urban area of Douala (Cameroon)].

    Science.gov (United States)

    Akono, P Ntonga; Tonga, C; Mbida, J A Mbida; Hondt, O E Ngo; Ambene, P Awono; Ndo, C; Magne, G Tamdem; Peka, M F; Ngaha, R; Lehman, L G

    2015-12-01

    An entomological survey was carried out from August to November 2013, in order to determine the vector system of a building site for social housing in a coastal periurban district of Douala (Cameroon). Mosquito larvae were collected and adult endophilic mosquitoes captured on volunteers, for a total sample of 4897 mosquitoes. Morpho-taxonomic techniques alongside molecular techniques enabled the identification of 4 species, all aggressive to humans: Cx. pipiens (22.3%), Ae. albopictus (0.3%), An. coluzzii and An. gambiae (77.4%). The overall average biting rate recorded was 41.73 bites/person/night (b/p/n). An. gambiae s.l. represents 90.82% of this aggressive fauna, followed by Cx. pipiens (8.58%) and Ae. albopictus (0.6%). The detection of CSP showed that An. gambiae was responsible for 100% of P. falciparum transmission. The overall mean Entomological Inoculation Rate (EIR) was 3.94 ib/p/n. Female An. gambiae mortality rates were 14.47%, 82.5% and 100% respectively with DDT, permethrin and deltamethrin. The proliferation of An. gambiae in this area during raining season, at the detriment of An. coluzzii Coetze & Wilkerson and An. melas Theobald known to be major malaria vectors in island and coastal areas of Africa, may owe to the forest that still colonises this coastal peri-urban locality. Residents should therefore make use of deltamethrin based protective measures.

  16. Notes on the blood-feeding behavior of Aedes albopictus (Diptera: Culicidae in Cameroon

    Directory of Open Access Journals (Sweden)

    Kamgang Basile

    2012-03-01

    Full Text Available Abstract Background The invasive mosquito Aedes albopictus is often considered a poor vector of human pathogens, owing to its catholic feeding behavior. However, it was recently incriminated as a major vector in several Chikungunya epidemics, outside of its native range. Here we assessed two key elements of feeding behavior by Ae. albopictus females in Yaoundé, Cameroon, Central Africa. Host preference was explored and the human-biting activity of females was monitored over 24 h to determine periods of maximum bite exposure. Findings Analysis of ingested blood in outdoor-resting females showed that Ae. albopictus preferentially fed on humans rather than on available domestic animals (95% of the blood meals contained human blood. Our results further showed that Ae. albopictus is a day-biting species in Yaoundé, with a main peak of activity in the late afternoon. Conclusion This is the first report on the feeding behavior of Ae. albopictus in Central Africa. The species is highly aggressive to humans and might therefore be involved in human-human virus transmission in this setting.

  17. Human resource development progress to sustain nuclear science and technology applications in Cameroon

    International Nuclear Information System (INIS)

    Full text: Cameroon as a Member of the International Atomic Energy Agency (IAEA) has made full use of the Agency's Technical Co-operation Programme in his effort to promote peaceful applications of nuclear science and technology at national level. This paper presents the progress made in the development of reliable human resources. Results obtained have been achieved through national and regional technical co-operation projects. Over the past twenty years, the development of human resources in nuclear science and technology has focused on the training of national scientists and engineers in various fields such as crop and animal production, human and animal nutrition, human health applications, medical physics, non-destructive testing in industry, groundwater management, maintenance of medical and scientific equipment, radiation protection and radioactive waste management. Efforts made also involve the development of graduate teaching in nuclear sciences at the national universities. However, the lack of adequate training facilities remains a major concern. The development of new training/learning methods is being considered at national level through network linking of national training centres with existing international training institutions, and the use of Information Communication Technologies (ICT) which offer great flexibility with regard to the number of trainees and the actual needs. (author)

  18. Spring water quality and usability in the Mount Cameroon area revealed by hydrogeochemistry.

    Science.gov (United States)

    Ako, Andrew Ako; Shimada, Jun; Hosono, Takahiro; Kagabu, Makoto; Ayuk, Akoachere Richard; Nkeng, George Elambo; Eyong, Gloria Eneke Takem; Fouepe Takounjou, Alain L

    2012-10-01

    Groundwater is the only reliable water resource for drinking, domestic, and agricultural purposes for the people living in the Mount Cameroon area. Hydrogeochemical and R-mode factor analysis were used to identify hydrogeochemical processes controlling spring water quality and assess its usability for the above uses. Main water types in the study area are Ca-Mg-HCO(3) and Na-HCO(3). This study reveals that three processes are controlling the spring water quality. CO(2)-driven silicate weathering and reverse cation exchange are the most important processes affecting the hydrochemistry of the spring waters. While tropical oceanic monsoon chloride-rich/sulfate-rich rainwater seems to affect spring water chemistry at low-altitude areas, strong correlations exist between major ions, dissolved silica and the altitude of springs. In general, the spring waters are suitable for drinking and domestic uses. Total hardness (TH) values indicate a general softness of the waters, which is linked to the development of cardiovascular diseases. Based on Na %, residual sodium carbonate, sodium adsorption ratio, and the USSL classification, the spring waters are considered suitable for irrigation. Though there is wide spread use of chemical fertilizers and intense urban settlements at the lower flanks of the volcano, anthropogenic activities for now seem to have little impact on the spring water quality. PMID:22539220

  19. Complete mitochondrial genome of the Nigeria-Cameroon chimpanzee, Pan troglodytes ellioti (Primates: Hominidae).

    Science.gov (United States)

    Wang, Bao-Hua; Wang, Yin-Hua; Tang, Ming-Gui; Chai, Hai-Xia; Xuan, Xing-Wei; Guo, Wei-Yan; Yang, Mu; Pu, Jian-Yi

    2016-05-01

    Chimpanzees are especially suited to teach us about ourselves, both in terms of their similarities and differences with human, and such important similarities and differences have also been noted for the incidence and severity of several major human diseases. In the present work, we report the entire mitochondrial genome of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) for the first time. Results shows that this mitogenome is 16,559 bp long and consists of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 putative non-coding region (D-loop region). The genomic organization and gene order are the same as other Chimpanzees. The whole nucleotide base composition is 31.1% of A, 30.7% of C, 12.9% G, and 25.3% T, with a slight A+T bias of 56.4%. Most of the genes are encoded on H-strand, except for the ND6 subunit gene and 8 tRNA genes. The complete mitochondrial genome sequence reported here provides useful genetic information for P. t. ellioti, and will further contribute to the comparative genomics studies in primates. PMID:25350739

  20. PROSTATIC ILLNESSES: EPIDEMIOLOGY AND TREATMENT WITH MEDICINAL PLANTS AT MAROUA (CAMEROON

    Directory of Open Access Journals (Sweden)

    Noumi E

    2011-03-01

    Full Text Available Three fieldworks were done at Maroua area in the Northern Cameroon to evaluate the epidemiology and the prophylaxis of prostatic illnesses, in 2008-2010. Data from the central Hospital of Maroua permitted us to appreciate the epidemiology. Interviews on 22 patients showed the risk factors for the apparition of prostatic illnesses and discussion with 27 phytotherapists indicated the treatments as done in the study area.Surgical intervention of Urogenital tumors related to prostatic illnesses occupy a preponderant place (51% in the surgery Service of the regional Hospital of Maroua. The patients prefer to go to traditional Doctors for treatment although there, the diagnoses by symptoms are approximate. Four plants are the more used by the traditional healers in the treatment of the prostatic illnesses: Azadirachta indica, Moringa oleifera, Sanseviera senegambica and Tamarindus indica; and 5 are new in the Cameroonian ethnobotany literature: Hyparrhenia nyassae, Hyphaene thebaica, Prosopis africana, Marsdenia sylvestri and Thelepogon elegans. The rate of monospecific recipe is lower (2/18 with respect to bispecific (12/18 or trispecific ones. The population of Maroua, both patients and phytotherapists, need some information on the feeding, the type of foods and the temperament of the prostate.

  1. Aurifilum, a new fungal genus in the Cryphonectriaceae from Terminalia species in Cameroon.

    Science.gov (United States)

    Begoude, Aime Didier B; Gryzenhout, Marieka; Wingfield, Michael J; Roux, Jolanda

    2010-10-01

    Native Terminalia spp. in West Africa provide a popular source of construction timber as well as medical, spiritual and social benefits to rural populations. Very little is, however, known regarding the diseases that affect these trees. During an investigation into possible diseases of Terminalia spp. in Cameroon, orange to yellow fungal fruiting structures, resembling those of fungi in the Cryphonectriaceae, were commonly observed on the bark of native Terminalia ivorensis, and on dead branches of non-native Terminalia mantaly. In this study the fungus was identified based on morphological features as well as DNA sequence data (ITS and beta-tubulin) and its pathogenicity was tested on T. mantaly seedlings. Our results showed that isolates of this fungus represent a previously undescribed genus in the Cryphonectriaceae, which we describe as Aurifilum marmelostoma gen. et sp. nov. Pathogenicity tests revealed that A. marmelostoma is pathogenic on T. mantaly. These tests, and the association of A. marmelostoma with disease symptoms on T. ivorensis, suggest that the fungus is a pathogen of this important tree. PMID:20559872

  2. Interhousehold variability and its effects on seed circulation networks: a case study from northern Cameroon

    Directory of Open Access Journals (Sweden)

    Jean Wencélius

    2016-03-01

    Full Text Available We present a detailed ethnographic case study of sorghum seed acquisitions in a smallholder farming society in northern Cameroon. The effects of variability in household demographics and socioeconomic status on observed patterns of seed provisioning are explored alongside other variables such as age and gender. Our data set comprised 223 seed acquisition events. Independence tests (Pearson's chi-square and Fisher's exact tests were carried out to test for significant dependencies between individual- or household-level characteristics and properties of seed acquisition events (categories of seed source, social relationship of exchange, and type of landrace. Results indicate that wealth is a structuring factor of the local seed circulation network in as much as it is highly correlated with household composition and size. Members from wealthy households benefit from a more diverse set of seed sources. Their greater number of coresidents and the importance of intrahousehold dynamics of seed transactions also play a role in making wealthy farmers more seed secure than others. The methodological implications of our findings indicate that when documenting seed exchange networks, the collection of data through a single informant or the undertaking of social network analyses at the household level may induce important biases.

  3. Human resource development progress to sustain nuclear science and technology applications in Cameroon

    International Nuclear Information System (INIS)

    Cameroon as a Member of the International Atomic Energy Agency (IAEA) has made full use of the Agency's Technical Co-operation Programme in his effort to promote peaceful applications of nuclear science and technology at national level. This paper presents the progress made in the development of reliable human resources. Results obtained have been achieved through national and regional technical co-operation projects. Over the past twenty years, the development of human resources in nuclear science and technology has focussed on the training of national scientists and engineers in various fields such as crop and animal production, human and animal nutrition, human health applications, medical physics, non destructive testing in industry, groundwater management, maintenance of medical and scientific equipment, radiation protection and radioactive waste management. Efforts made also involve the development of graduate teaching in nuclear sciences at the national universities. However, the lack of adequate training facilities remains a major concern. The development of new training/learning methods is being considered at national level through network linking of national training centres with existing international training institutions, and the use of Information Communication Technologies (ICT) which offer great flexibility with regard to the number of trainees and the actual needs. (author)

  4. Characterization of Doayo and Kapsiki taurine cattle breeds of Cameroon in their natural environment.

    Science.gov (United States)

    Ebangi, A Lot; Achukwi, M D; Messine, O; Abba, D

    2011-08-01

    Data were collected on live weight (LW), heart girth (HG), height-at-withers (HW), trunk length (TL), age, sex, and coat color of 207 taurines cattle--122 of the Doayo (Namchi) breed and 85 of the Kapsiki (Kirdi) breed. The animals, aged 1 to 20 years, were selected from 60 herds randomly selected from villages of Poli of Faro and Mokolo of Tsanga, divisions of the North and Far North Regions of Cameroon. The data were analyzed using the SAS program with a linear model, applying standard tests. Results indicated no breed effect (P > 0.05) in the growth trends of LW, HG, HW, and TL. HG and TL were highly significantly (P 0.05) significantly. The breeds attained maturity as from 4 years. In the absence of breed effect (P > 0.05), a single regression equation was established for the estimation of live weight as thus LW = -244.42 (±22.57) kg + 2.49 (±0.23) HG + 1.04 (±0.25) TL, with HG contributing up to 70% of total variation and TL, 2%. This equation could be used to develop a measuring band useful in the rural environment for commercial and clinical veterinary purposes.

  5. Nutritional Composition of Five Varieties of Pap Commonly Consumed in Maroua (Far-North, Cameroon

    Directory of Open Access Journals (Sweden)

    Ponka Roger

    2015-09-01

    Full Text Available The aim of this study was to determine the nutritional composition of five varieties of pap (cereal product commonly consumed in Maroua, city of the Far-North Region of Cameroon. The proximate composition (moisture, ash, protein, lipid, and crude fibre was determined by standard AOAC methods. Minerals (calcium, magnesium, sodium, potassium, iron, zinc, copper and manganese were determined by atomic absorption spectrophotometry and phosphorus was determined colorimetrically. Amino acid composition was determined by ion-exchange chromatography. All the pap varieties had a very high carbohydrate content (79.47-85.29 g/100 g dry matter. Appreciable levels of phosphorus and potassium were recorded in all the pap varieties (137.5-231.0 mg/100 g dry matter and 198.20-322.22 mg/100 g dry matter, respectively. Consumption of each pap (100 g by children 1-2 year old would meet 9.86-17.46% and 0.08-19.51% of their daily recommended intake respectively for protein and minerals. Leucine and glutamic acid were the most abundant essential amino acids and non-essential amino acids respectively in the pap. Essential amino acids in most of the pap samples met the recommended children requirement of the FAO/WHO/UNU for 1-2 year old children except methionine+cysteine and lysine.

  6. Vulnerability to Climate Change of Mangroves: Assessment from Cameroon, Central Africa

    Directory of Open Access Journals (Sweden)

    Isabella Zouh

    2012-11-01

    Full Text Available Intertidal mangrove ecosystems are sensitive to climate change impacts, particularly to associated relative sea level rise. Human stressors and low tidal range add to vulnerability, both characteristics of the Doula Estuary, Cameroon. To investigate vulnerability, spatial techniques were combined with ground surveys to map distributions of mangrove zones, and compare with historical spatial records to quantify change over the last few decades. Low technology techniques were used to establish the tidal range and relative elevation of the mapped mangrove area. Stratigraphic coring and palaeobiological reconstruction were used to show the longer term biological history of mangroves and net sedimentation rate, and oral history surveys of local communities were used to provide evidence of recent change and identify possible causes. Results showed that the seaward edge of mangroves had over two thirds of the shoreline experienced dieback at up to 3 m per year over the last three decades, and an offshore mangrove island had suffered 89% loss. Results also showed low net sedimentation rates under seaward edge mangroves, and restricted intertidal elevation habitats of all mangroves, and Avicennia and Laguncularia in particular. To reduce vulnerability, adaptation planning can be improved by reducing the non-climate stressors on the mangrove area, particularly those resulting from human impacts. Other priorities for adaptation planning in mangrove areas that are located in such low tidal range regions are to plan inland migration areas and strategic protected areas for mangroves, and to undertake management activities that enhance accretion within the mangroves.

  7. International Database of Volcanic Ash Impacts

    Science.gov (United States)

    Wallace, K.; Cameron, C.; Wilson, T. M.; Jenkins, S.; Brown, S.; Leonard, G.; Deligne, N.; Stewart, C.

    2015-12-01

    Volcanic ash creates extensive impacts to people and property, yet we lack a global ash impacts catalog to organize, distribute, and archive this important information. Critical impact information is often stored in ephemeral news articles or other isolated resources, which cannot be queried or located easily. A global ash impacts database would improve 1) warning messages, 2) public and lifeline emergency preparation, and 3) eruption response and recovery. Ashfall can have varying consequences, such as disabling critical lifeline infrastructure (e.g. electrical generation and transmission, water supplies, telecommunications, aircraft and airports) or merely creating limited and expensive inconvenience to local communities. Impacts to the aviation sector can be a far-reaching global issue. The international volcanic ash impacts community formed a committee to develop a database to catalog the impacts of volcanic ash. We identify three user populations for this database: 1) research teams, who would use the database to assist in systematic collection, recording, and storage of ash impact data, and to prioritize impact assessment trips and lab experiments 2) volcanic risk assessment scientists who rely on impact data for assessments (especially vulnerability/fragility assessments); a complete dataset would have utility for global, regional, national and local scale risk assessments, and 3) citizen science volcanic hazard reporting. Publication of an international ash impacts database will encourage standardization and development of best practices for collecting and reporting impact information. Data entered will be highly categorized, searchable, and open source. Systematic cataloging of impact data will allow users to query the data and extract valuable information to aid in the development of improved emergency preparedness, response and recovery measures.

  8. Geochemical signatures of the diffuse CO2 emission from Brava volcanic system, Cape Verde

    Science.gov (United States)

    Rodriguez, F.; Bandomo, Z.; Barros, I.; Dias Fonseca, J.; Fernandes, P.; Rodrigues, J.; Melian Rodriguez, G.; Padron, E.; Dionis, S.; Sonia, S.; Gonçalves, A.; Fernandes, A.; Hernandez Perez, P. A.; Perez, N.

    2010-12-01

    Brava (67 km2) the smallest of the populated Cape Verde islands, lies at the southwestern end of the archipelagic crescent. Brava volcanic system has no documented historical eruptions, but its youthful volcanic morphology and the fact that earthquake swarms still occur indicate the potential for future eruptions. A geochemical survey of diffuse gas emissions was carried out in Brava island during February and March 2010. For this survey 228 sampling sites were selected all over the island to perform soil CO2 efflux measurements, using a portable accumulation chamber and an IR sensor, and soil temperature measurements at a depth of 30-50 cm. Soil gas samples were collected at 40 cm depth for chemical (He, H2, N2, CO2, CH4, Ar and O2) and isotopic (δ13C-CO2) analysis in 32 selected sampling sites. CO2 efflux values ranged from non-detectable up to 1.343 g m-2 d-1. To quantify the total diffuse CO2 emission from Brava volcanic system, a CO2 efflux map was constructed using sequential Gaussian simulations (sGs). Most of the studied area showed background levels of CO2 efflux (˜2 g m-2 d-1), while peak levels (>1300 g m-2 d-1) were mainly identified at Vinagre and Baleia areas. The total diffuse CO2 output from Brava volcanic system was estimated about 41.6 t d-1. The analysis of the carbon isotopic signature of the CO2 in the soil atmosphere provides an insight for evaluating the origin of the diffuse CO2 emission. Observed δ13C-CO2 values ranged from -20.86 to -1.26 ‰. A binary plot of CO2 concentrations versus δ13C-CO2 values allows us to represent three major geochemical reservoirs (atmospheric air, volcanic gas, and biogenic gas) and their related mixing lines. The chemical and isotopic analysis of Brava soil gas samples suggest a mixing with deep-seated CO2 and biogenic gas for the diffuse CO2 emission from Brava volcanic system. The lack of visible volcanic gas emission in Brava highlights the importance of monitoring diffuse CO2 emission to improve its

  9. Volcanic field elongation, vent distribution and tectonic evolution of continental rift: The Main Ethiopian Rift example

    Science.gov (United States)

    Mazzarini, Francesco; Le Corvec, Nicolas; Isola, Ilaria; Favalli, Massimiliano

    2015-04-01

    Magmatism and faulting operate in continental rifts and interact at a variety of scales, however their relationship is complex. The African rift, being the best example for both active continental rifting and magmatism, provides the ideal location to study the interplay between the two mechanisms. The Main Ethiopian Rift (MER), which connects the Afar depression in the north with the Turkana depression and Kenya Rift to the south, consists of two distinct systems of normal faults and its floor is scattered with volcanic fields formed by tens to several hundreds monogenetic, generally basaltic, small volcanoes and composite volcanoes and small calderas. The distribution of vents defines the overall shape of the volcanic field. Previous work has shown that the distribution of volcanic vents and the shape of a field are linked to its tectonic environment and its magmatic system. In order to distinguish the impact of each mechanism, we analyzed four volcanic fields located at the boundary between the central and northern MER, three of them (Debre Zeyit, Wonji and Kone) grew in the rift valley and one (Akaki) on the western rift shoulder. The elongation and shape of the fields were analyzed based on their vent distribution using the Principal Component Analysis (PCA), the Vent-to-Vent Distance (VVD), and the two dimensional symmetric Gaussian kernel density estimate methods. We extracted from these methods several parameters characterizing the spatial distribution of points (e.g., eccentricity (e), eigenvector index (evi), angular dispersion (Da)). These parameters allow to define at least three types of shape for volcanic fields: strong elongate (line and ellipse), bimodal/medium elongate (ellipse) and dispersed (circle) shapes. Applied to the natural example, these methods well differentiate each volcanic field. For example, the elongation of the field increases from shoulder to rift axis inversely to the angular dispersion. In addition, the results show that none of

  10. Calibration of microbolometer infrared cameras for measuring volcanic ash mass loading

    Science.gov (United States)

    Carroll, Russell C.

    Small spacecraft with thermal infrared (TIR) imaging capabilities are needed to detect dangerous levels of volcanic ash that can severely damage jet aircraft engines and must be avoided. Grounding aircraft after a volcanic eruption may cost the airlines millions of dollars per day, while accurate knowledge of volcanic ash density might allow for safely routing aircraft around dangerous levels of volcanic ash. There are currently limited numbers of satellites with TIR imaging capabilities so the elapsed time between revisits can be large, and these instruments can only resolve total mass loading along the line-of-sight. Multiple small satellites could allow for decreased revisit times as well as multiple viewing angles to reveal the three-dimensional structure of the ash cloud through stereoscopic techniques. This paper presents the design and laboratory evaluation of a TIR imaging system that is designed to fit within the resource constraints of a multi-unit CubeSat to detect volcanic ash mass loading. The laboratory prototype of this TIR imaging system uses a commercial off-the shelf (COTS) camera with an uncooled microbolometer sensor, two narrowband filters, a black body source and a custom filter wheel. The infrared imaging system detects the difference in attenuation of volcanic ash at 11 mum and 12 mum by measuring the brightness temperature at each band. The brightness temperature difference method is used to measure the column mass loading. Multi-aspect images and stereoscopic techniques are needed to estimate the mass density from the mass loading, which is the measured mass per unit area. Laboratory measurements are used to characterize the noise level and thermal stability of the sensor. A calibration technique is developed to compensate for sensor temperature drift. The detection threshold of volcanic ash density of this TIR imaging system is found to be from 0.35 mg/m3 to 26 mg/m3 for ash clouds that have thickness of 1 km, while ash cloud densities

  11. Gravity and magnetic investigations of the Mono-Inyo Volcanic Chain, Mono Basin, California

    Science.gov (United States)

    Pera, A. A.; Ponce, D. A.; McPhee, D. K.; Battaglia, M.

    2010-12-01

    The Mono Inyo volcanic chain is a 25-km long, north-south trending series of domes and craters extending southward from Mono Lake and into the west moat of Long Valley Caldera. Based on the Holocene history of eruptions in the area, the chain appears to hold the greatest potential for renewed magmatic activity (Hildreth, 2004). To better characterize the geometry and structure of Mono Basin for future dynamic modeling of the Mono Inyo volcanic chain a new gravity and magnetic survey was conducted. We collected gravity data at over 320 stations in and around the northern and central region of the Mono-Inyo volcanic chain and around Mono Lake in the summer of 2010. Regional gravity data was collected at one-mile spacing and data collected on profile lines was collected at quarter-mile intervals. We collected magnetic data on major roads along several transects across Mono Basin that include one coincident with a seismic refraction line (Hill and others, 1985). Rock samples were collected for analysis of density and magnetic susceptibility. The new gravity and magnetic data will be compiled with pre-existing data from studies dating back to the 1960’s (Pakiser and others, 1960, 1976; Christensen, 1969) to produce new isostatic gravity and magnetic anomaly maps. Preliminary isostatic gravity and magnetic maps from pre-existing data show the presence of gravity and magnetic lows in Mono Lake and Long Valley Caldera where low density volcanic sediments are prevalent; gravity highs were observed to the east and west of Mono Lake and to the east of Long Valley Caldera. A region with a high magnetic anomaly lies to the east of the volcanic chain. Two-dimensional forward modeling of potential field data along profiles that extend across Mono Basin will constrain the density and magnetization distribution, stratification and structural geology of the Mono-Inyo volcanic chain. These efforts are critical to improve dynamic modeling of Sierran range-front faulting and dike

  12. Remote Sensing of Volcanic Clouds: Sulfur Gases and Plume Top Topography

    Science.gov (United States)

    Crisp, Joy A.

    1999-01-01

    New absorption line parameters for H2S were published and submitted to the Gestion et Etude des Informations Spectroscopiques Atmospheriques (GEISA) and high resolution transmission molecular absorption (HITRAN) databases. These new absorption line parameters will make it possible to use observations from the future Tropospheric Emission Spectrometer (TES) instrument [Earth Observing System (EOS) Chemistry Mission (CHEM) platform] to make more accurate H2S measurements if it observes an H2S-rich volcanic cloud. H2S is the second most abundant volcanic sulfur gas, and like SO2, it also converts to H2SO4 aerosols and can have a climate impact. A paper on the Moderate-resolution Imaging-Spectroradiometer (MODIS) SO2 alert is being revised. New aspects in the revision include verification of the SO2 alert during the EOS mission; factors affecting SO2 detection at thermal infrared, ultraviolet, and microwave wavelengths; radiative transfer tests; more description of satellite instruments; and thermal surface alert installed for MODIS. Her research involves the use of remote sensing to generate maps of plume top altitude. This parameter is important for models of volcanic eruption, aircraft hazards, and climate impact. The topographic shape of the top surface of a volcanic plume can provide information necessary to understand the physics controlling the injection and dispersal of a volcanic plume in the atmosphere. Glaze et al. describe the application of a photoclinometric technique to volcanic plumes. The software algorithm has been improved to account for more general plume and illumination geometries and for easily extracting position information directly from Advanced Very High-Resolution Radiometer (AVHRR) level 1B data. Testing of the algorithm has focused on acquiring AVHRR data for a variety of volcanic plumes in an effort to identify problems with the software as well as model sensitivities. The plumes chosen were erupted from volcanoes at a variety of

  13. Eruptive modes and hiatus of volcanism at West Mata seamount, NE Lau basin: 1996-2012

    Science.gov (United States)

    Embley, Robert W.; Merle, Susan G.; Baker, Edward T.; Rubin, Kenneth H.; Lupton, John E.; Resing, Joseph A.; Dziak, Robert P.; Lilley, Marvin D.; Chadwick, William W.; Shank, T.; Greene, Ron; Walker, Sharon L.; Haxel, Joseph; Olson, Eric; Baumberger, Tamara

    2014-10-01

    present multiple lines of evidence for years to decade-long changes in the location and character of volcanic activity at West Mata seamount in the NE Lau basin over a 16 year period, and a hiatus in summit eruptions from early 2011 to at least September 2012. Boninite lava and pyroclasts were observed erupting from its summit in 2009, and hydroacoustic data from a succession of hydrophones moored nearby show near-continuous eruptive activity from January 2009 to early 2011. Successive differencing of seven multibeam bathymetric surveys of the volcano made in the 1996-2012 period reveals a pattern of extended constructional volcanism on the summit and northwest flank punctuated by eruptions along the volcano's WSW rift zone (WSWRZ). Away from the summit, the volumetrically largest eruption during the observational period occurred between May 2010 and November 2011 at ˜2920 m depth near the base of the WSWRZ. The (nearly) equally long ENE rift zone did not experience any volcanic activity during the 1996-2012 period. The cessation of summit volcanism recorded on the moored hydrophone was accompanied or followed by the formation of a small summit crater and a landslide on the eastern flank. Water column sensors, analysis of gas samples in the overlying hydrothermal plume and dives with a remotely operated vehicle in September 2012 confirmed that the summit eruption had ceased. Based on the historical eruption rates calculated using the bathymetric differencing technique, the volcano could be as young as several thousand years.

  14. Exploratory Data Analysis Using a Dedicated Visualization App: Looking for Patterns in Volcanic Activity

    Science.gov (United States)

    van Manen, S. M.; Chen, S.

    2015-12-01

    Here we present an App designed to visualize and identify patterns in volcanic activity during the last ten years. It visualizes VEI (volcanic explosivity index) levels, population size, frequency of activity, and geographic region, and is designed to address the issue of oversampling of data. Often times, it is difficult to access a large set of data that can be scattered at first glance and hard to digest without visual aid. This App serves as a model that solves this issue and can be applied to other data. To enable users to quickly assess the large data set it breaks down the apparently chaotic abundance of information into categories and graphic indicators: color is used to indicate the VEI level, size for population size within 5 km of a volcano, line thickness for frequency of activity, and a grid to pinpoint a volcano's latitude. The categories and layers within them can be turned on and off by the user, enabling them to scroll through and compare different layers of data. By visualising the data this way, patterns began to emerge. For example, certain geographic regions had more explosive eruptions than others. Another good example was that low frequency larger impact volcanic eruptions occurred more irregularly than smaller impact volcanic eruptions, which had a more stable frequencies. Although these findings are not unexpected, the easy to navigate App does showcase the potential of data visualization for the rapid appraisal of complex and abundant multi-dimensional geoscience data.

  15. A new method for improving the dairy production sector in a developing country: The case of Cameroon

    International Nuclear Information System (INIS)

    Full text: Milk production in Cameroon was estimated at 184 000 tons. Yet the demand of milk products is far above production and 24% of national consumption is imported. Due to urbanization and population growth, milk production needs to double by the year 2020 if it is to meet the demand. Therefore, efforts have been made to increase dairy production. However the efforts of non-governmental organizations, research and government institutions failed to significantly boost domestic dairy production because farmers did not see the economic gain associated with potential biological improvements. A hypothesis was then devised whereby an integration of interventions at the level of farmers associating nutrition, health, reproduction and management would bring more economic benefits to smallholder farmers and improve dairy production. This involved reviewing dairy research done in Cameroon, carrying out a participatory rural appraisal and an economic opportunity survey at selected dairy farms, setting up various interventions on farms, investigating postpartum return to oestrus, evaluating milk quality and the impact of integrated interventions. This paper intends to critically evaluate the results of different studies and present the integrated method developed in this research. It also aims to set up guidelines for a successful sustainable improvement of dairy production in Cameroon. The study involved reviewing dairy research done in Cameroon. A participatory rural appraisal and an economic opportunity survey were carried out in selected dairy farms. On-farm interventions were set up, investigating cow reproduction, evaluating milk quality, setting up an artificial insemination centre and the impact of integrated interventions. Guidelines for improvement of the dairy sector were drawn. These series of experiments were designed to evaluate the impact of interventions carried out holistically. In small-scale dairy systems the uptake and use of research results by wider

  16. Using Spatial Density to Characterize Volcanic Fields on Mars

    Science.gov (United States)

    Richardson, J. A.; Bleacher, J. E.; Connor, C. B.; Connor, L. J.

    2012-01-01

    We introduce a new tool to planetary geology for quantifying the spatial arrangement of vent fields and volcanic provinces using non parametric kernel density estimation. Unlike parametricmethods where spatial density, and thus the spatial arrangement of volcanic vents, is simplified to fit a standard statistical distribution, non parametric methods offer more objective and data driven techniques to characterize volcanic vent fields. This method is applied to Syria Planum volcanic vent catalog data as well as catalog data for a vent field south of Pavonis Mons. The spatial densities are compared to terrestrial volcanic fields.

  17. An ethical approach to socio-economic information sources in ongoing vulnerability and resilience studies: the Mount Cameroon case

    Directory of Open Access Journals (Sweden)

    Maria Ilaria Pannaccione Apa

    2012-07-01

    Full Text Available The study of the vulnerability of facing natural and man-made hazards, with the related resilient answers belong to the complex and articulate field of social sciences called ‘Disaster Anthropology’. Vulnerability is generally defined as a weak point in facing an aggressive event that is difficult to manage. Resilience is the subsequent capacity for self-repair after a sustained natural or anthropogenic stress. Consequently, the theoretical model of economic resilience is the ability to restore an economic background that can support the gradual recovery of social benefits following a disaster. Moreover, the presence in the territory of different systems of production (natural eco-systems and/or technical systems should allow multi-resilient communities. The mathematical structure of these economic theorems makes their practical application difficult inside an ethno-anthropological context, as it conflicts with cultural variables of the socio-structural fabric. An example can be given by some urban and rural family structures that are settled around the Mount Cameroon volcano (southwest Cameroon, in which the general psychological pressure increases because of both the constant exposure to natural hazards and the vulnerability arising from its social environment (e.g. castes, forced housing allocation, cultural estrangement to local chiefdom. Therefore, the rational heuristic model to be adopted in this social vulnerability study is performed by several combined analyses that have many interpretive obstacles. In 2009, within FP7-MIA-VITA, the first fieldwork mission for the study of socio-economic development of communities living around Mount Cameroon was launched. This completed 108 interviews across several social groups of different ethnicities and religions. The resulting information is being re-tested and verified from the second fieldwork mission in 2011, for completion of the study area.

  18. Electrical charging of ash in Icelandic volcanic plumes

    CERN Document Server

    Aplin, Karen L; Nicoll, Keri A

    2014-01-01

    The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcan...

  19. The impact of signing a memorandum of understanding on reproductive health with the Ministry of Public Health in Cameroon.

    Science.gov (United States)

    Leke, Robert J I; Njotang, Nana P; Shearon, Azong B; Wankah, Charlotte A

    2014-10-01

    Health statistics relating to Millennium Development Goals 4 and 5 are poor for most low-resource countries. Professional societies can assist governments to improve these health indicators. For an effective collaboration, the Society of Gynaecologists and Obstetricians Cameroon (SOGOC) and the Ministry of Public Health signed a memorandum of understanding on reproductive health. A major consequence of this collaboration was the ease of transfer of competence associated with SOGOC adopting a monitoring and evaluation role, which has improved quality of care. The impact of this collaboration for the Society has been significant; SOGOC is recognized as a partner and has an opportunity to play a leadership role in issues concerning reproductive health.

  20. Siltation and Pollution of Rivers in the Western Highlands of Cameroon: a Consequence of Farmland Erosion and Runoff

    OpenAIRE

    Djoukeng, Henri Grisseur; Tankou, Christopher Mubeteneh; Degré, Aurore

    2015-01-01

    In the Western Highlands agro-ecological zone of Cameroon, rivers are constantly silted and polluted with eroded sediment and waste from cultivated land. This study characterizes and quantifies the amount of material coming from plots cultivated in the Méloh Watershed. In a natural rocky-bottomed well measuring 0.90 m deep, 3 m long, and 2.5 m wide, for a period of three years we performed the collection, differentiation, and measurement of trapped sediment in the cultivated part of river tha...