Ehinlafa, O. E., Abdulsalam et al. (13 contributing authors)
In this study, f o F2 variability diurnally, seasonally and annually was investigated during a Low Solar Epoch (LSE) over Ilorin (latitude 8.31°N, longitude 4.34°E, dip latitude 2.95 o ), a low latitude station along the equatorial anomaly trough. The percentage variability index () was used for the analysis. The percentage variability index () is lowest during the day (2-17%); increases during night to (8-55%); and attained the highest magnitude during pre-sunrise phase (17-68%), for the period of LSE. Two major peaks were noticed in V R : the pre-sunrise peak, which is higher, and the post-sunset peak. Annually, peaks at 44% for the pre-sunrise phase, and 37% for the post-sunset phase, during the LSE. The rapid electron drift away from the equator coincides with subsequent rise in the percentage variability index immediately after sunset for all the seasons.
Critical frequency (foF2)Variability index () 
Odusina, B. O., Oyeyemi et al. (13 contributing authors)
Olax manii stems were collected in Ikire, Osun State, Nigeria. Using the hydrodistillation process, essential oil was extracted from the stem of Olax manii. To ascertain the chemical composition of the essential oil, Gas chromatography mass spectrometry (GCMS) technique analysis was employed. Using doses ranging from 100 to 25 µg/ml, the antioxidant properties of the essential oil were examined using the 2, 2-Diphenyl-1 picryl hydroxyl (DPPH) radical scavenging activity method. The results of the Gas chromatography mass spectrometry (GC-MS) analysis indicated that the main chemical constituents were squalene (6.18 %), amyrone (4.49%), and neophytadiene (4.22 %). The minor constituents were identified as limonene (0.23 %), caryophyllene (0.31 %) and phytol (1.62 %). The essential oil radical scavenging activity at a concentration of 100 mg/ml was compared to the standard ascorbic acid at the same concentration and it revealed that the essential oil exhibited a significant percentage radical scavenging activity of 78.52 %. The percentage radical scavenging activities increased with increase in concentrations of the essential oil. The Essential oil constituents which possess antioxidant activities could be responsible for the antioxidant activities and ethnomedicinal uses of Olax manii.
Oguntunde, B. O., Ologunye et al. (7 contributing authors)
The mandatory wearing of face masks orchestrated by the COVID-19 pandemic has brought some complexities to the ability of face recognition systems in identifying such faces. Thus, this study examined the performance of some selected machine learning algorithms: Convolutional Neural Network (CNN), Linear discriminant analysis (LDA), Logistic Regression (LR), K-Nearest Neighbour (KNN), Support Vector Machine (SVM), Naïve Bayes (NB) and Decision Tree (DT) for the recognition of masked and unmasked human faces; and developed a face recognition system based on the algorithm with the best performance. The dataset was composed of 11,792 masked and unmasked facial images collected from Kaggle online repository. The set was divided into 70%, 20% and 10% respectively for training, testing and validation each for the masked and the unmasked face images. The images were augmented randomly for training, with some rotated 30 degree, some zoomed 20%, some shifted horizontally by 10% in width, some shifted vertically by 10% in height and some flipped horizontally. The performance analysis of the algorithms presented accuracies of 99% and 99% for the CNN; 93% and 98% for LDA; 93% and 93% for LR; 86% and 78% for the NB; 70% and 70% for the KNN; 64% and 45% for the DT; and 92% and 98% for the SVM respectively for training and cross validation. Overall, the CNN recorded the highest recognition accuracy. Thus, a CNN user-friendly face recognition, system was developed, and tested with a number of real-life human masked and unmasked faces which showed excellent recognition performance. The implementation was carried out with appropriate Python machine libraries. The developed system could be very useful for access control and surveillance. Therefore, this study recommends the adoption of the developed systems for face recognition-based security system.
This paper presents an implementation of a home automation system using smart phone Bluetooth with Arduino for the switching and control of home appliances. It aimed at reducing stress for the physically challenged, elderly, and younger children with an easy control of the home appliances and likewise reduction of risk of electrocution from the source of control. With this automated control unit, users can comfortably operate their electrical installations or appliances from distances ranging from 30 m to 100 m away from the point of control using smart phone. The control unit comprises a four-channel relay module, an Arduino Uno board (AUB) based on the ATmega328 microcontroller, an HC-05 Bluetooth module, and a manual backup switch or alternative. The central processing unit is the Arduino Uno board to which every other component is connected. The Load (devices/appliances) to be controlled or operated is connected to the Arduino Uno board (AUB) via the relay. The Arduino board is programmed using the Arduino integrated development environment (IDE), with instructions that controls other units of the circuits. An Arduino Bluetooth controller is installed on the phone, to be used as a remote controller and to enable communication interface between the phone and the Arduino based control unit. In other words, the Bluetooth module connected to the Arduino board receives signals and/or instructions through phone Bluetooth via controller installed on the phone. An LCD (led crystal display) is used as display output of information uploaded on the Arduino Uno board to know the working state of the circuit. It was found that the automated control unit is of great benefit to users in terms of convenience in operating their appliances, including the elderly, and physically challenged people as it reduces their stress and difficulty in moving from point to point in order to control their home lightings and appliances.
Balogun, Oluwatimilehin B.1, and Osazuwa Isaac B.2
Physical geodetic survey of the Nigeria landmass was undertaken with the aim of furnishing engineers and scientists with vital geodetic information which have not been adequately available but required for the development of a standard national economic framework. The basic data used for the study were the absolute gravity field values, and the recorded coordinates and elevations at the Primary Gravity Network of Nigeria (PGNN) base stations. The absolute gravity data were processed using the appropriate mathematical and computational procedures to deduce geodetic information which include geoid undulation, height above the geoid, deflections of the vertical, distance from the earth’s centre of mass to the reference ellipsoid and geoid, and the gravity potential value at the geoid. Comparison was also made between the WGS’84 and the geoid in the study area. Geoid undulations were found to range from 16.53 to 28.35 m and the deflections of the vertical ranged between 0.738685 to 10.28328 arc second. Height above the topography ranged from -16.38 m in Warri to +1257.13 in Jos. The distance from the earth’s centre of mass to the WGS’84 reference ellipsoidal surface was maximum at Oron (6377988.04 m) and least at Illela (6376941.31 m). Similarly, the distance from the earth’s centre of mass to the geoid was also maximum at Oron (6378008.39 m) and minimum in Illela (6376961.659 m). The interpolation of the distances from the earth’s centre of mass to the spheroidal surface at each base station gave the definition of the WGS’84 ellipsoid over the continental Nigeria landmass while the interpolation of the distances from the earth’s centre of mass to the geoidal surface gave the definition of the geoid over the continental Nigeria landmass. The average gravity potential at the geoid was evaluated as 62375050.41 m 2 s -2 . The geoid over the continental Nigeria landmass was found to be comparably smooth as the WGS’84 ellipsoid over the region though they differ in terms of vertical separation. The quantitative difference in mGal corresponding to the vertical separation between the WGS’84 reference ellipsoid and the geoid was computed as 6.8042 mGal. The values of the deflections of the vertical at each station of the PGNN gave the angular correction to be applied when combining satellite-based ellipsoidal measurements and geoid-based physical geodetic measurement. Based on the significant range of the deflections of the vertical across the continental area of Nigeria, it was concluded that the physical structure of the lithosphere beneath the study area must be highly complex and heterogeneous.
Physical geodetic survey Primary Gravity Network of Nigeria (PGNN)geoid undulationsdeflections of the vertical
Famuyiwa, S. O., Ayoola M. D. et al. (7 contributing authors)
A medicinal plant is any plant containing substances that are effective therapeutically or are precursors for drug manufacture in one or more of its organs. This work was a comparative study of the hypoglycaemic and hyperglycaemia-lowering activities of the methanol extracts of the leaf, stem, and root barks of Xylopia aethiopica used folklorically in the management of type 2 diabetes mellitus with the view of determining its most active morphological part. The pulverized leaves, stem and root barks of the plant were separately subjected to cold extraction using methanol to obtain leaf, stem and root barks extracts respectively. The hypoglycaemic and antihyperglycaemic effects of the extracts were carried out on normoglycaemic and glucose-induced hyperglycaemic rats, respectively at 100, 200 and 400 mg/kg using glibenclamide (5 mg/kg) as positive control. The most effective antihyperglycaemic doses of the extracts were used to determine its anti-diabetic activity on streptozotocin-induced diabetic rats. The results obtained from the study were subjected to analysis of variance (ANOVA), followed by Student–Newman-Keuls post hoc tests and p< 0.05 was considered significant. The results of the study showed that the root bark extract of X. aethiopica did not cause hypoglycaemia in rats at all the tested doses while hypoglycaemia was obtained at 400 mg/kg of the leaf and stem bark extracts. In the hyperglycaemia-lowering experiment using glucose loaded rats’ model, the leaf, stem and root bark extracts gave 10, 13, 10, 29; 35, 36, 38, 41 and 25, 27, 33, 44 % blood glucose levels reduction at 0.5, 1, 2 and 4 h, respectively which showed the stem bark as the most active plant part especially at 0.5-2 h. In the streptozotocin-induced hyperglycaemic rats experiment, the order of antihyperglycaemic effect of the morphological parts of X. aethiopica is, stem bark extract > leaf extract > root bark extract. It was concluded from the results obtained from the study that the stem bark extract of Xylopia aethiopica was the most active plant part both in glucose and streptozotocin-induced hyperglycaemia and it does not cause hypoglycaemia at low doses.
Okanlawon, T. S., Ogundele et al. (10 contributing authors)
Leucaena leucocephala is a fast-growing leguminous plant this is used in the treatment of intestinal diseases and as birth control. This work was geared toward investigating the phytochemical attributes and the antimicrobial actions of methanol and distilled water crude extracts from the stem bark of Leucaena leucocephala in the ratio of 3:2 on nineteen bacterial species. The antimicrobial activity of the plant extract was done with the use of the agar diffusion technique in line with the National Committee for Clinical Laboratory Standards. The extract was located to be energetic against sixteen bacterial traces at a concentration of 35 mg/mL except for Bacillus anthracis, Clostridium sporogenes, and Pseudomonas fluorescens . The zones of inhibition exhibited by means of the extract towards the organisms ranged from 10.00 mm to 20.00 mm. The MIC exhibited by the extract ranged from 2.19 mg/ml to 8.75mg/ml while the MBC ranged from 4.38 mg/ml to 17.5 mg/ml. The effects of the extract on bacterial species were compared with the use of selected antibiotics such as streptomycin, and ampicillin. The phytochemical parts of the extract include tannins, glycosides, alkaloids, phenols, and terpenoids. Results from this research confirmed that the stem bark extract of Leucaena leucocephala exhibited antimicrobial activity against the selected bacteria and support the usefulness of this plant in folklore treatments.
Kolawole, I. O., Ebuehi et al. (10 contributing authors)
Alafia barteri is valued for its effectiveness in the traditional medicine system in Nigeria and other African countries. This study aims at evaluating the hypolipidemic effect of the aqueous and ethanol leaf and root extracts of Alafia barteri in formaldehyde-induced arthritic mice. 77 healthy Swiss albino male mice (30-35 g) were randomized into eleven groups of five mice each and extracts were administered for 10 days at 200 mg/kg and 400 mg/kg. Arthritis was induced by sub-plantar injection of 0.1 mL of 2 % formaldehyde. Serum lipid profile was evaluated after blood sample collection. Results of this study revealed that the aqueous and ethanol leaf extracts caused significant reduction(p˂0.05) in triglyceride and total cholesterol levels, but increased HDL-cholesterol levels compared to the arthritic control which is suggestive of their hypo-lipidemic effects in arthritic mice.
Ehinlafa, O. E., Johnson et al. (10 contributing authors)
The F2 region critical frequency ( f o F2 ) and peak electron density ( N m F2 ) morphology was investigated over Ilorin (latitude 8.31°N, longitude 4.34°E) during a Low Solar Epochs (LSE), a station along the equator anomaly trough. Diurnally, f o F2 and N m F2 are visibly more prominent during the day than at night with two characteristic peaks: pre-noon and post-noon peaks. The f o F2 and N m F2 pre-noon peak magnitude range: (7.7–8.3 MHz) and (7.3–8.6) × 10 11 /m -3 respectively is less compared to the f o F2 and N m F2 post-noon peak magnitude range: (7.3–9.7 MHz) and (6.7–11.7) ×10 11 /m -3 respectively. Seasonally, the highest values were attained during the post-noon peak in the equinoctial months compared to the solstices months, and also, annually, the post-noon peak is higher than the pre-noon peak. The rapid electron drift away from the equator is responsible for the sharp drop in f o F2 and N m F2 after sunset in all seasons. Seasonal peaks in f o F2 and N m F2 are suspected to be controlled by the enhanced E × B drifts and the onset and turn-off of solar ionization, which is consistent with some earlier results obtained at some stations in the African region during low solar epoch periods.
Egwu, H. A., Yilwa et al. (14 contributing authors)
Hyptis suaveolens , an aromatic plant commonly called Daddoya-ta-daji in Hausa language, is traditionally used as medicine and food. It is used as stimulant, antirheumatic, carminative, against parasitic diseases, headaches, infection of the uterus, stomach, and skin diseases. It is found growing in both oil polluted and non-oil polluted environment. Oil pollution of land is a challenge due to the presence of heavy metals and volatile organic compounds which are harmful to crops and plants. This study investigated the phytoconstituents of the methanol leaf extract as well as antimicrobial activities of Hyptis suaveolens collected from polluted and unpolluted sites. Methanol leaf extracts of H. suaveolens were screened for crucial phytochemicals using standard methods. The in vitro antimicrobial activity was carried out using agar disc-diffusion method by Yahaya et al . (2018), using Mueller Hinton agar medium and potatoes dextrose agar in petri plates seeded with clinical isolates of Escherichia coli, Salmonella typhi, Shigella sp, Staphylococcus aureus (bacteria), Candida albicans and Aspergillus niger (fungi) respectively, and the zone of inhibition determined. The phytochemical results showed that methanol extract of both the polluted and non-polluted H. suaveolens leaves exhibited the presence of some number of bioactive compounds. Gas Chromatography–Mass Spectrometry (GC-MS) of polluted and non-polluted leaves of H. suaveolens identified 13 and 21 compounds, respectively such as Octadec-9-enoic acid, 2-Ethylacridine, Methyl ester, Tetracyclo [4.4.1.1(7,10).0(2,5)] dodec-3-en-11-ol, 1,2-Diphenyl-1-isocyanoethane and 7-Isopropyl-1, 1, 4a-trimethy l-1,2,3,4,4a,9,10,10 aocta -hydrophenanthrene. These chemical compounds are considered biologically and pharmacologically important. The results from assessment of the antimicrobial potential of H. suaveolens (L.) on pathogenic microorganisms showed that the pathogenic microorganisms revealed inhibition zones ranging from 6 to 18 mm. This data indicates that the unpolluted methanol extract of H. Suaveolens exhibits a higher bioactive potential compared to the extract derived from polluted leaves. This disparity suggests that oil pollution may have a detrimental impact on the biochemical properties of the plant.
Ajayi, Olulope Olufemi, Okhani et al. (4 contributing authors)
A Body Shape Index (ABSI) is a new adiposity metric that has been linked with chronic metabolic diseases such as diabetes mellitus, type 2, cardiovascular diseases, and cancer risk in some studies. ABSI is an anthropometric index that takes into account waist circumference (WC), body mass index (BMI), and height. The aim of this study was to determine the relationship of ABSI with clinical and biochemical indices in undergraduates. This cross-sectional study involved 97 undergraduate students of Edo State University Uzairue, Edo State, Nigeria (16–26 years old). They comprised 65 females and 32 males. Information on socio-demography was obtained from administered semi-pretest questionnaire. Anthropometric indices; body weight, height, waist circumference, hip circumference and mid-upper arm circumference were determined using standard methods. BMI, ABSI, waist hip ratio and waist height ratio were calculated. Blood pressure, pulse rate, pulse pressure, saturation of peripheral oxygen (SPO 2 ), and body composition including lean body mass, body water, metabolism and so on. as well as plasma glucose and total cholesterol were determined by standard methods. Age, body weight, height, mid-upper arm circumference, systolic blood pressure, lean body mass, metabolism were significantly higher in males, while body age, SPO 2 and fat were significantly higher in females than males (p<0.05). ABSI positively correlated with height, waist circumference, pulse rate, visceral fat, metabolism, and lean body mass (p<0.05). Observations in this study show that ABSI could be a good index of assessing abdominal obesity, hence, its recommendation for obesity screening in studies is suggested.
A body shape indexBiochemical indicesBody mass indexClinical indicesObesity
Omojoyegbe, R. T., Olatunji et al. (8 contributing authors)
The rise in the incidence of side effects of many synthetic antimicrobial agents and prevalence of multidrug resistant bacteria has spurred scientists on the research for plant based antimicrobial of therapeutic potentials. Ocimum gratissimum L. presents such potential of high medicinal value. This plant is used in Nigeria traditionally as condiments and for treatment of various ailments. This study is aimed to determine the phytochemical and antimicrobial property of ethanol and aqueous extracts of O. gratissimum L . leaves. Phytochemical screening of the leave extracts confirmed the presence of Steroid, Tannins, Flavonoid, Terpenoid, Alkaloid, Saponin and Phlobatannis. Ethanol and aqueous extracts were obtained from the powdered leaves of O. gratissimum using ethanol and distilled water respectively. These were later filtered and the filtrates were concentrated in water bath at 50 o C. Mueller-Hinton agar was used for the antibacterial susceptibility using the agar well diffusion method. For ethanol extract, all the isolates were susceptible at 0.2g/mL, 0.1g/mL and 0.05g/mL concentrations. However, for aqueous extract, all the isolates were resistant at 0.05g/ml and 0.025g/ml but at 0.2g/ml concentration all the isolates were susceptible. Staphylococcus aureus was resistant at 0.1g/ml, except Pseudomonas aeruginosa and Bacillus cereus which were susceptible with a diameter 15mm, and 14mm respectively. Ciprofloxacin used as positive control also inhibited the growth of the bacterial isolates with the diameter of zone of 25mm. Results obtained from this study showed that the extracts of Ocimum gratissimum L. has antibacterial activities against the selected gastrointestinal tract pathogenic bacteria and also possess some bioactive compounds.
