Physical Volcanology of Pyroclastic Tephra Deposit at Batoke Mt. Cameroon, West Africa: An Over View.

In this contribution, we report an overview of the physical attributes of pyroclastic deposit at the foot of Mt. Cameroon, West Africa. In the deposit three facies types; which are the lava flow, the lapilli and ash are common. The ash is the dominant facies and occurs irregularly in alternation with the lapilli. The most common types of depositional features include cm-dm planar beds and impact sags. We infer from field observations of facies types, clasts types and depositional features that this deposit is a phreatomagmatic fall deposit which resulted from an interaction between lava flow and surface water. The occurrence in the deposit of accretionary lapilli, impact sags, fragments of country-rock and juvenile clasts is ambiguous evidence in support of phreatomagmatic activity. The presence of a lava flow flanked by the tephra pile, the lack of accidental clasts, and the scarcity of bombs are evidence in support of a surface water-lava flow interaction.KEY WORDS: Pyroclastic Deposit, Batoke, Mt. Cameroon

PUBLIC POLICY ON EDUCATION IN CONTEMPORARY CAMEROON: PERSPECTIVES, ISSUES AND FUTURE DIRECTIONS

Public policy is critical in defining the direction of any institution, organization or country, including its education sector. An education policy as a public policy enhances, authenticates and regulates educational processes in a nation. A good education policy must be anchored on the attributes of good policy. Since independence, the Cameroon government has adopted different educational legislations which have guided educational processes over the years. While some scholars view these as constituting Cameroon’s education policy, others argue that their disjointed and incomprehensive nature does not qualify what exists as education policy. This conceptual paper critically examined public policy on education in contemporary Cameroon vis-à-vis the attributes of a good policy. It fortifies the existing structure for potential subsequent studies in education policy, and correlation with such variables as system effectiveness. The paper draws from the fact that educational policy lapses have constituted backdrop for the recent and ongoing conflict in the Anglophone regions of the country. Hence, it raises issues and offers insight intended to stimulate education policy makers towards action. The authors conclude that there is a big vacuum in terms of comprehensiveness, quality, adequacy and access in Cameroon’s education policy as a close comparative look at the situation in other African countries shows that Cameroon does not have one. The paper thus recommends on the urgent need for a National Conference on Education of the like of the 1995 Education Forum tasked among others to review all disjointed educational legislations and establish a comprehensive education policy to guide and regulate educational practices in the country’s two sub-systems of education.  Article visualizations

Phreatomagmatic deposits and stratigraphic reconstruction at Debunscha Maar (Mt Cameroon volcano)

The Debunscha Maar (DM) is located on the southwest flank of Mount Cameroon, an active stratovolcano on the Cameroon volcanic line (CVL). Here, we present the physical characteristics of the pyroclastic deposits at DM with the aim of deciphering tephra emplacement mechanisms, evolution of water–magma interaction and reconstructing the stratigraphy beneath the maar. From GPS measurements, the crater has long and short axes of 500 m and 320 m, respectively. Generally, the pyroclastic deposits are well stratified and present a variety of depositional bed forms including structureless/massive beds, massive beds with faint internal stratifications, inversely graded beds, lens- shaped units, impact sags, cross lamination, planar beds as well as dune-like beds. Clast sizes include ash, lapilli-tuff, bombs and blocks (pyroclastic breccia), with clast lithologies consisting of entrained lithics of porous ankaramite pillow lavas, lithified sediments (sandstone and shale) and juvenile material. The porous ankaramite pillow lavas have glassy margins and vesicle zonations typical of pillow lavas formed by subaqueous eruption. The pillow fragments are more common in early-formed eruption products at the base of the deposit. The lithified sandstones show planar laminations and together with the shales occur predominantly in stratigraphic positions above the ankaramite pillow lavas. The juvenile materials include basaltic bombs with low vesicularity (b15%) and moderate vesicularity (15–50%). The bombs have chilled surfaces and their abundance increases towards the top of the deposit. The presence of accretionary lapilli, fragments of country-rock and juvenile clasts with ragged surfaces as well as curved and chilled margins, is unambiguous evidence in support of phreatomagmatic activity. Of the observed lithic clasts, only the pillow lavas would appear to have the porosity necessary to furnish the required amount of water to feed the phreatomagmatic maar eruption. The clast stratigraphy suggests that the maar is underlain by ankaramite pillow lava that erupted on a consolidated sedimentary substratum. Studying deposits resulting from maar eruptions has a direct implication for hazards assessment at areas of active maar volcanism because many surface processes occur around such volcanoes well after the eruptive activities have stopped

Incorporating biological knowledge in the search for gene × gene interaction in genome-wide association studies

We sought to find significant gene × gene interaction in a genome-wide association analysis of rheumatoid arthritis (RA) by performing pair-wise tests of interaction among collections of single-nucleotide polymorphisms (SNPs) obtained by one of two methods. The first method involved screening the results of the genome-wide association analysis for main effects p-values < 1 × 10-4. The second method used biological databases such as the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes to define gene collections that each contained one of four genes with known associations with RA: PTPN22, STAT4, TRAF1, and C5. We used a permutation approach to determine whether any of these SNP sets had empirical enrichment of significant interaction effects. We found that the SNP set obtained by the first method was significantly enriched with significant interaction effects (empirical p = 0.003). Additionally, we found that the "protein complex assembly" collection of genes from the Gene Ontology collection containing the TRAF1 gene was significantly enriched with interaction effects with p-values < 1 × 10-8 (empirical p = 0.012)

Hundreds of variants clustered in genomic loci and biological pathways affect human height

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.

Histopathological and cytochemical studies of fetal and neonate primate spinal cord after experimental maternal protein-calorie malnutrition in the squirrel monkey (Saimiri sciureus)

M.S.John R. Strang

Practicalities in the Production of Maize by Persons with Visual Impairment (PVI) in Cameroon

After a field survey we carried out to know the practical processes involved in large scale production of maize by farmers with blindness in Cameroon, a number of hitches were identified. This paper studies and proposes technical solutions to these difficulties with a surmounting objective to improve upon the economic, and hence, social prosperity of all persons with blindness. The surveys involved field observations of the farmers with blindness, buttressed with interviews, while they were actually at work in the farm cultivating the maize

Practicalities in the Production of Maize by Persons with Visual Impairment (PVI) in Cameroon

After a field survey we carried out to know the practical processes involved in large scale production of maize by farmers with blindness in Cameroon, a number of hitches were identified. This paper studies and proposes technical solutions to these difficulties with a surmounting objective to improve upon the economic, and hence, social prosperity of all persons with blindness. The surveys involved field observations of the farmers with blindness, buttressed with interviews, while they were actually at work in the farm cultivating the maize