Federal University of Technology

Multi‐model <scp>CMIP5</scp> and <scp>CORDEX</scp> simulations of historical summer temperature and precipitation variabilities over West Africa

ABSTRACT The mean climatology, inter‐model variability and spatio‐temporal patterns of temperature and precipitation over West Africa from Coupled Model Intercomparison Project 5 ( CMIP5 ), CMIP5_SUBSET [ensemble of global climate models driving COordinated Regional climate Downscaling EXperiment ( CORDEX )] and CORDEX multi‐model ensembles are evaluated and intercompared for the monsoon season (June–September). We find that, while CORDEX fails to outperform the simulated mean climatology of temperature by the CMIP5 ensembles, it substantially improves precipitation and provides more realistic fine‐scale features tied to local topography and landuse. This improved performance over the region is found to depend more on the internal models physics than the driving boundary conditions and results from a more consistent and realistic simulation of monsoon precipitation across the various regional climate models ( RCMs ). Rotated empirical orthogonal function ( REOF ) analysis indicates that the CORDEX ensemble captures better the spatio‐temporal variability of both temperature and precipitation (first REOF mode), in particular depicting the warming and Sahel precipitation recovery in recent decades over West Africa. On the other hand, the spatial patterns and associated time series of the last two REOF modes in CORDEX mostly follow the CMIP5_SUBSET pointing towards a strong role of the boundary forcing in the RCM simulation of precipitation variability.

Efficient numerical techniques for computing the Riesz fractional-order reaction-diffusion models arising in biology

Studies on the biology and aquaculture potential of feral catfish<i>Heterobranchus bidorsalis</i>(Geoffroy St. Hilaire 1809) (Clariidae)

Haematological profile of Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) was determined. Haematocrit values, haemoglobin concentrations, erythrocyte and leucocyte counts, mean cell haemoglobin concentration, sodium and potassium ions concentrations were 24.75±1.23%, 5.43±0.25 g/100 ml, 1.99±0.52 106/mm3 and 7.25±0.60 104/mm3, 22.11±0.77%, 802.52±36.97 and 83.54±5.05 mg/1, respectively. H. bidorsalis fingerlings were subjected to a range of salinities, 0, 3, 6, 9, 12 and 15 ppt. The optimum salinity range for survival and good growth performance was determined as 0–3 ppt. Survival was >85% from 0–9 ppt with no significant differences (P>0.05), but decreased progressively as salinity increased. Qualitative and quantitative assays of digestive enzymes in the different regions of H. bidorsalis guts revealed an array of carbohydrases, proteases and lipases. Enzyme activity was restricted to the stomach, duodenum and ileum with fewer enzymes recorded in the stomach. The pattern of distribution and relative activity of enzymes correlated with its euryphagous diet. Parasitological examinations conducted on the skin and internal organs of H. bidorsalis yielded a variety of parasites which included three protozoans, two monogeans, six digeneans, four cestodes, two nematodes, two annelids and four copepods. No acanthocephalan infection was detected. Protocephalus sp. (Cestoda) and Allocreadium sp. (Trematoda) had the highest prevalence (>81%) followed by digenean metacercaria (35%). The implications of these results in relation to the aquaculture potential of this catfish is discussed.

Improving Secondary School Students' Achievement and Retention in Biology Through Video-based Multimedia Instruction

The study examined the effects of video-based multimedia instruction on secondary school students' achievement and retention in biology. In Nigeria, 120 students (60 boys and 60 girls) were randomly selected from four secondary schools assigned either into one of three experimental groups: Animation + Narration; Animation + On-screen Text; Animation + Narration + On-screen Text or a control group. The pretest, posttest experimental, and control group design was adopted. A 50-item multiple-choice objective test termed Biology Achievement Test (BAT) was used for collecting data. The validated BAT was tested for reliability using Kuder Richardson (KR20), which yielded 0.89. T-test, analysis of covariance (ANCOVA), and Scheffe’s post-hoc analysis were used in determining the significant differences among the four groups. The results showed that there was no statistically significant difference among the experimental groups. Generally, students under multimedia instruction performed better than their colleagues in the conventional teaching method. However, students in conventional teaching method had better retention than other groups.

Physics in Africa

Africa tends to be isolated and sometimes forgotten when it comes to scientific research and in particular physics. But the region has great potential, being home to the youngest population in the world, and despite a variety of issues, there has been steady, albeit uneven progress towards establishing a scientific infrastructure. Ten African researchers discuss the diverse challenges and opportunities faced by physicists across the continent. Ten African researchers discuss the varied challenges and opportunities faced by physicists across the continent. Rabia Salihu Sa’id is a full professor of Atmospheric Physics at Bayero University, Kano, in Nigeria. She holds a PhD, MSc and BSc in Physics and an MSc in Environment and Development, and is an expert in the effects of dust aerosols on climate and air quality measurements. In 2015, she received the OWSD (Organization for Women in Science for the Developing World)/ TWAS (The World Academy of Sciences)/Elsevier Foundation Award for Early Career (Physics), which rewards and encourages women working and living in developing countries who are in the early stages of their scientific careers, having often overcome great challenges to achieve research excellence. Ibiyinka Fuwape has been a professor of physics at the Federal University of Technology, Akure, Nigeria since 1989. She is currently the Vice Chancellor of the Michael and Cecilia Ibru University, Agbarha-Otor, Delta State, Nigeria. Her research interests include theory of chaos and application of nonlinear dynamics in coupled oscillator systems, neuronal systems, and lower and upper atmospheric research. She is an alumna of the Schlumberger Faculty of the Future Fellowship programme. Alain Moise Dikandé (full professor in physics) is Head of the Physics Department, Faculty of Science, University of Buea, Cameroon. He is an Alexander von Humboldt Fellow in the ‘Experienced Researchers’ Category, a Senior Associate of the Abdus Salam International Centre for Theoretical Physics (ICTP, Trieste, Italy), guest editor of the special issue of the Journal of the Optical Society of America (JOSA A and B): Optics in Africa and member of the editorial board of Journal of Optics. Jamal Mimouni is an Algerian astrophysicist, who received his higher education between Algiers University and the United States (PhD in Particle Physics in 1985, University of Pennsylvania). He is the head of a graduate programme in astrophysics at Constantine 1 University in Algeria, and the President of the African Astronomical Society. He is an active participant in the debate on science and society in the Arab-Muslim World. Francis Hasford is the Head of Medical Physics at the University of Ghana and Ghana Atomic Energy Commission, Secretary General of the Federation of African Medical Physics Organizations, expert medical physicist for the International Atomic Energy Agency and member of the IOMP (International Organization for Medical Physics) Web Sub-committee. He received his PhD from the University of Ghana and is an associate of the International Centre for Theoretical Physics. He is the recipient of the 2016 International Union of Pure and Applied Physics (IUPAP)/IOMP Young Scientist Award in Medical Physics. Delia Haynes did her PhD at Trinity Hall at the University of Cambridge, followed by a postdoctoral fellowship with the Pfizer Institute for Pharmaceutical Materials Science, also at Cambridge. She has been at Stellenbosch University since 2007, where she is now a professor in the Department of Chemistry and Polymer Science. Delia is the chair of the Steering Committee to form the African Crystallographic Association. Irvy (Igle) Gledhill spent time at the University of California, Los Angeles and Stanford before moving to the Council for Scientific and Industrial Research in South Africa, her home country. She is now Visiting Professor of Flow Physics at the University of the Witwatersrand. She is a past president of the South African Institute of Physics and a Vice-President of the Network of African Science Academies. She edits . George Amolo is a professor of physics and Director of the School of Physics and Earth Science, The Technical University of Kenya, Nairobi, and a research associate in Computational Modelling and Materials Science with the Kenya Education Network (KENET). He received his PhD from the University of the Witwatersrand, South Africa, and worked in the University of Eldoret and Moi University, Eldoret, Kenya, before moving to the Technical University of Kenya in 2016. Omololu Akin-Ojo received his BSc and MSc Physics degrees from the University of Ibadan, and his PhD from the University of Delaware (USA). Following two postdoctoral stints at Boston University and the Abdus Salam International Centre for Theoretical Physics (ICTP) Trieste, Italy, he returned to Africa — first to Nigeria and now Rwanda as Director of the East African Institute for Fundamental Research , a physics training and research hub. His main research interest is in condensed matter physics and its applications for African development and advancement. Nashwa Eassa is an associate professor of physics and the Dean of the Deanship of Scientific Research at Al Neelain University. She undertook a postdoctoral fellowship in the Nanophotonics group at Nelson Mandela Metropolitan University (NMMU), South Africa. She holds a PhD in physics from NMMU and Master of Science in material physics and nanotechnology from Linköping University, Sweden.