Quality Changes in Hermetically Stored Corn Caused by Fungi and Sitophilus Zeamais

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 6297 and 6333 VT RIB hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn quality was evaluated by using mold counts, aflatoxin levels, free fatty acids, germination, gas composition, and nutritional composition. The results showed that hermetic storage is effective at suppressing mold growth, minimizing aflatoxins levels and maintaining the nutritional content of corn stored at 11 and 15% MC w.b. Non-hermetic storage was better at preserving germination. Mold count, aflatoxin, free fatty acids generally increased with temperature, moisture content and storage time

Book Reviews

This issue of the CJAS includes reviews of two important books: The Mind of Africa by William Abraham, that was recently re-issued in paperback, and Building the Nation: Seven Notable Ghanaians, edited by Mercy Akrofi- Ansah and Esi Sutherland-Addy. We think that these commentaries provide critical illumation of these important texts, and we are grateful to Professor Emeritus Ivan Addae-Mensah, and Drs Amoah-Boampong and Richmond Kwesi for their thoughtful reflections

Traditional medicines as a mechanism for driving research innovation in Africa

The outcomes from recent high profile deliberations concerning African health research and economic development all point towards the need for a mechanism to support health innovation on the continent. The mission of the African Network for Drugs and Diagnostics Innovation (ANDI), is to promote and sustain African-led health product innovation to address African public health needs through the assembly of research networks, and building of capacity to support human and economic development. ANDI is widely viewed as the vehicle to implementing some of these recommendations. There is tremendous opportunity for Africa, to leverage the expertise in natural products and traditional medicines in support of this objective to kick-start innovation. This report highlights key recommendations that have emerged through expert forums convened by ANDI on the challenges, opportunities and prospects for investing in this important area of research

Hispidulin And Other Constituents Of Scoparia dulcis Linn

Phytochemical investigation of the ethanol extract of the whole plant of Scoparia dulcis, has resulted in the isolation of 4, 5, 7-trihydroxy-6-methoxyflavone, commonly called hispidulin and a steroidal glycoside, β-sitosterol-β-D-glucoside.  This is the first isolation of the two compounds from S. dulcis. Also isolated and characterized were the previously reported 6-me-thoxybenzoxazolinone, friedelan-3-one and scopadulcic acid B. Structural elucidation was done on the basis of spectroscopic data interpretations (IR, UV, NMR and EIMS).  Using the Tetrazolium-based colorimetric selective assay, hispidulin was found to be inactive against HIV-1/IIIB in MT-4 cells whereas the same test on the aqueous extract of the plant was positive

Exploring Mobile Social Networking Sites Continuance Intention from the Perspective of Network Externalities and Mobile Value

Key shifts in the nature and characteristics of technology have led to evolutions in social media usage. For the first time in history, the internet is being accessed from more mobile devices than desktop computers. This revolution is especially felt among social networking sites, many of whom have presciently developed and released mobile applications of their platforms. Drawing from the Perceived Value Theory, Network Externalities and the Expectation Confirmation Theory of IS Continuance, we tested a model that sought to explain the effect of Network Externalities on Perceived Value and in turn Continuance Intention. Data was collected from 452 students from a university in Ghana and analyzed using the Partial Least Square approach to Structural Equation Modeling. Results from the current study showed that Referent Network Size and Perceived Complementarity had significant effects on both Utilitarian and Hedonic Value as well as Satisfaction. Hedonic Value, Utilitarian Value and Satisfaction in turn were found to be significant predictors of Continuance Intention. In all, the model accounted for 58.0% of the variance in continuance intention. The implications and limitations of the current study are discussed, and directions for future research proposed

An exploration of course tutors’ reported teaching practices in a distance learning institution in Ghana

Quality teacher education is contingent upon the pedagogical practices of teacher educators. While various studies have explored these practices, few have situated them in the broader framework of teacher education models. This article leverages tutors’ perceived pedagogical approaches and learners’ demographic characteristics to interrogate the implementation of transformative pedagogy within Ghana’s distance learning setting. Through the analysis of semi-structured interviews with course tutors and senior leaders, rooted in the concept of transformative distance learning (DL) pedagogy drawn from Paulo Freire’s work (1970), we highlight the model’s effectiveness, emphasising the role of facilitation and dialogue, in the creation of empowering learning experiences. This study provides insights for comprehending, reflecting on, responding to, and learning from the evolving practices of course tutors in a distance learning institution in Ghana. Based on these insights, we propose recommendations to enhance the model’s pedagogical potential, which offers valuable implications for advancing teacher education policies and practices in Ghana and other African countries with similar distance learning models

Physical Aspects of Cell Culture Substrates: Topography, Roughness, and Elasticity

The cellular environment impacts a myriad of cellular functions by providing signals that can modulate cell phenotype and function. Physical cues such as topography, roughness, gradients, and elasticity are of particular importance. Thus, synthetic substrates can be potentially useful tools for exploring the influence of the aforementioned physical properties on cellular function. Many micro‐ and nanofabrication processes have been employed to control substrate characteristics in both 2D and 3D environments. This review highlights strategies for modulating the physical properties of surfaces, the influence of these changes on cell responses, and the promise and limitations of these surfaces in in‐vitro settings. While both hard and soft materials are discussed, emphasis is placed on soft substrates. Moreover, methods for creating synthetic substrates for cell studies, substrate properties, and impact of substrate properties on cell behavior are the main focus of this review. The cellular environment plays a significant role in cell phenotype and function. As such, physical properties of cell culture substrates including topography, roughness, and elasticity may be utilized to investigate the influence of these physical cues on the cellular response. In this review, strategies for modulating the physical properties of surfaces, the influence of these changes on cell responses, and the promise and limitations of these surfaces in in‐vitro settings are highlighted, with a particular emphasis on elastic substrates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90132/1/336_ftp.pd

Constituents of the Roots of Dichapetalum pallidum and Their Anti-Proliferative Activity

As part of our search for bioactive compounds from the Dichapetalaceae, repeated chromatographic purification of the roots of a hitherto unexamined species, Dichapetalum pallidum, led to the isolation of the newly occurring 7-hydroxydichapetalin P (1) and the known dichapetalins A (2) and X (3). Also isolated were the known compounds friedelin-2,3-lactone (4), friedelan-3-one (6), friedelan-3β-ol (7) and pomolic (8), as well as the dipeptide aurantiamide acetate (5). The compounds were characterized by direct interpretation of their IR, 1D NMR and 2D NMR spectral data and by comparison of their physico-chemical data, including their chromatographic profiles, with the literature and authentic samples in our compound library for the genus Dichapetalum. The compounds were assayed for their anti-proliferative activities against the human T-lymphocytic leukemia (Jurkat), acute promyelocytic leukemia (HL-60) and T-lymphoblast-like leukemia (CEM) cell lines. Overall, dichapetalin X showed the strongest (3.14 μM) and broadest cytotoxic activities against all the leukemic cell lines tested, exhibiting even stronger activities than the standard compound, curcumin