Journal of African Christian Biography: v. 1, no. 6

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. Michael Timneng and Jeremiah Chi Kangsen: Christianity Beyond the Missionary Presence in Cameroon. 2. Michael Timneng. 3. Jeremiah Chi Kangsen. 4. Recent Print and Digital Resources Related to Christianity in Africa

The Influence of ZnO Layer Thickness on the Performance and Electrical Bias Stress Instality in ZnO Thin Film Transistors

University of Buea supported the first author during the writing of this manuscript Open access articleThin Film Transistors (TFTs) are the active elements for future large area electronic applications, in which low cost, low temperature processes and optical transparency are required. Zinc oxide (ZnO) thin film transistors (TFTs) on SiO2/n+-Si substrate are fabricated with the channel thicknesses ranging from 20 nm to 60 nm. It is found that both the performance and gate bias stress related instabilities of the ZnO TFTs fabricated were influenced by the thickness of ZnO active channel layer. The effective mobility was found to improve with increasing ZnO thickness by up to an order in magnitude within the thickness range investigated (20 – 60 nm). However, thinner films were found to exhibit greater stability in threshold voltage and turn-on voltage shifts with respect to both positive and negative gate bias stress. It was also observed that both the turn on voltage (Von) and the threshold voltage (VT) decrease with increasing channel thickness. Moreover, the variations in subthreshold slope (S) with ZnO thickness as well as variations in VT and Von suggest a possible dependence of trap states in the ZnO on the ZnO thickness. This is further correlated by the dependence of VT and Von instabilities with gate bias stress

Engendering Children of the Resistance: Models of Gender and Scouting in China, 1919–1937

In the 1920s and 1930s, Chinese adapted scouting, which had originally been developed to masculinize British youth as future colonial troops. While Chinese families and teachers valued scouting as a form of outdoor recreation, Chiang Kai-shek and the Guomindang after 1927 connected scouting to preparation for military training. In addition to fostering masculinity among boys, the Chinese Scouting Association also directed Girl Scouts with new models of patriotic girlhood. The Guomindang promoted the distinct femininity of the Girl Scouts and channeled girls’ patriotism into nursing. As China entered World War II, Girl Scouts became significant symbols of patriotism in an increasingly militarized children’s culture. The Guomindang showcased Yang Huimin, a Girl Scout and heroine in the Battle of Sihang Warehouse, as a spokesperson for the Nationalist cause, but it could not fully control her public image. Keywords: Girl Scouts, scouting, gender roles, China, World War I

Turbulence Measurements in Submerged Water Jets by Electromagnetic Induction Anemometry

This paper describes the measurement and data analysis of the turbulence in a two-dimensional water jet discharging from a thin slot into a large body of stationary water having the same width as the slot. Tap water without additives was used as the flow medium. The electromagnetic induction method (commonly known as magnetohydrodynamics, or the MHD method) was used to sense the fluctuation velocities in the diffusion zone of the jet. A DC magnet was placed outside the flow field with the magnetic flux density of 885 Gauss perpendicular to the plane of homogeneity of the two-dimensional flow field. A small probe in the flow field sensed voltage changes due to the turbulent velocities. The induced voltages picked up at the electrodes were fed into a high input 12 impedance (about 10 ohms) differential amplifier. The output from the amplifier was recorded on tape which was later read into a hybrid computer for analyzing the variances, autocorrelation and spectrum of the turbulence signal. Turbulent velocities induce fluctuating electric potentials everywhere in the flow field whenever a magnetic flux is present, and hence set up fluctuating currents between any two points of different potentials. These currents have an equalizing effect on the induced voltage, thus causing the differential fluctuating voltage sensed by the electrodes in a turbulent flow to be less than the true value. The voltage reduction effect was experimentally determined to be a constant value by comparing the measured variance of turbulence in a water jet by the MHD method with the variance in an air jet using hot-wire anemometry. The constant reduction factor should have no effect on the normalized autocorrelation and spectrum results of the water jet

Alfalfa mosaic virus: Occurrence and variation among isolates from forage legumes in Ethiopia

Filed samples and seedlings of 51 leguminous forage species were tested for alfalfa mosaic virus (AMV) in routine monitoring of seed multiplication fields of the International Livestock Research Institute (ILRI), Ethiopia. The virus was detected in 24 species and a solanaceous weed Solanum nigrum. Of these, the following 17 species are being reported for the first time as hosts of the virus in world literature: Aeschynomene falcata, Centrosema pascuorum, Chamaecrista rotundifolia, Desmanthus virgatus, Desmodium intortum, Leucaena leucocephala, Macroptilium atropurpureum, Macroptilium lathyroides, Macrotyloma axillare, Medicago truncatula, Neonotonia wightii, Sesbania sesban, Stylosanthes scabra, Trifolium calocephala, T. steudneri, T. tembense and Vigna parkeri. The solanaceous weed S. nigrum was suspected to play a role in the virus epidemiology. The level of seed infection varied from 0.00 percent to about 13.00 percent. Infectivity studies on 5 isolates of the virus revealed heterogeneity in prevalent AMV isolates. Two major strains were identified, based on the development of necrotic local lesions on Vigna unguiculata accessions. One of the isolates which failed to incite local necrotic lesions on unguiculata infected Phaseolus vulgaris cTop Crop systematically. Differences among isolates were also noticed in their concentration in different hosts as indicated by ELISA absorbance values

Teacher Quality and the Quality of Technical and Vocational Education and Training Courses: Implications for Sustainable Development in Cameroon

Teacher quality remains an important subject for debate and the role of TVET in reducing unemployment and facilitating sustainable development cannot be overemphasized. Here, we present a critical engagement with the literature on teacher quality; the quality of TVET courses and the implications these have for sustainable development. First, we trace the policy background and motivations that led to the introduction of TVET in Cameroon. Next a critical examination of what counts as teacher quality and yardsticks for defining teacher quality is provided. Further, there is a discussion on what TVET teacher training programs need, to be considered qualitative. Finally, focus is on the major issues in TVET teacher supply and quality, current pathways to TVET teaching in Cameroon, the resulting challenges and benchmarks. To ensure that Cameroon has suitably-skilled human capital, it is suggested that if diligently considered, the benchmarks could assist policy makers to design and implement quality TVET policies following the five steps proposed by the European Parliament and the Council of the European Union. These include, evaluating the existing situation of the TVET system, developing a strategy to reform the system, implementing the strategy, evaluating the impact and continuous monitoring and evaluation of performance in the sector. Keywords: Teacher quality, TVET policy, Teacher training, Certification pathways, Sustainability DOI: 10.7176/JEP/12-2-01 Publication date: January 31st 202

Secondary metabolites of oil palm isolates of Ganoderma zonatum Murill. from Cameroon and their cytotoxicity against five human tumour cell lines

Three lanostane-type triterpenoids [lanosta-7,9(11),24-trien-3-one 15,26-dihydroxy, lanosta-7,9(11),24- trien-26-oic,3-hydroxy and ganoderic acid y], four steroids[ (22E,24R)-ergosta-7,22-dien-3β,5α.6β-triol, 5α,8α-epidiory (22E,24R-ergosta-6,22-dien-3β-ol, ergosta-5,7,22-trien-3β-ol,7 (ergosterol) and ergosta- 7,22-dien-3β-ol,6] and a benzene derivative (dimethyl phthalate) were isolated from ethyl acetate crude extract of Ganoderma zonatum Murill. of oil palm from Cameroon. Their structures were elucidated by nuclear magnetic resonance (NMR), electron impact ionization mass spectrum experiments (EI-MS) and by comparing with the data reported in literature. The highly oxygenated lanostane triterpenoid - ganoderic acid y- showed moderate cytotoxicity against two human tumour cell lines, SMMC-7721 (liver cancer) and A549 (lung cancer) with IC50 values of 33.5 and 29.9 μM, respectively and no activity on HL-60, MCF-7 and SW480, while lanosta-7,9(11),24-trien-3-one,15;26-dihydroxy and lanosta- 7,9(11),24-trien-26-oic,3-hydroxy, showed no activity. The three lanostane triterpeniods had the same molecular formula, molecular weight, behaviour on the TLC plates, with the same retention factor value of 3 (when petroleum ether-acetone was used in the ratio of 3:1), but with slightly different structures. These compounds have not been reported occurring together from any other species of Ganoderma. Their simultaneous occurrence might thus, serve as a diagnostic chemotaxonomic character for G. zonatum, The 1H NMR data is provided for the first time for lanosta-7,9(11),24-trien-26-oic,3-hydroxy.Key words: Secondary metabolites, Ganoderma zonatum, chemotaxonomic character, cytotoxicity

Text-Based Inference Instruction for Elementary Grade Children with Reading Comprehension Difficulties: An Intervention Research

The current study investigated the effects of inference instruction on text-based inferences by third graders who are below average in reading comprehension but average in reading fluency and cognitive abilities. Text-based inferences occur when the preceding text has an identifiable causal antecedent. Participants were randomly assigned and attended twelve 30-minute sessions of the inferences training intervention. We have included strategies for integrating information from the text to improve reading comprehension skills. We provide an overview of how specific text-based instruction influences reading comprehension processes and outcomes and can lead to increased reading comprehension. The comparison of pretest and posttest results in the experimental group showed a significant gain in the following variables: generating inferences and providing arguments for using rules and constraints. Finally, we discuss how consideration of these potential sources of instruction has practical implications for designing and selecting instructional materials