Showing papers by "University of Nigeria, Nsukka published in 2022"

Microplastics in agroecosystems-impacts on ecosystem functions and food chain

Abstract: This work reviews microplastic's impact on agroecosystem components and possible effects on the food chain. Microplastics are sized

Influence of transition metal doping on physiochemical and antibacterial properties of ZnO Nanoparticles: A review

Abstract: Bacterial infections are considered a genuine health challenge worldwide. The resistance against antibiotics by these microorganisms is seen as a more serious health challenge. Multidrug resistance bacteria-pathogens have led to an increase in proliferation of opportunistic microorganism. The vast majority of these bacterial cell sizes are range from hundreds of nanometers (nm) to tens of micrometers (mm), hence making it difficult to visualize on surfaces. Because of these challenges scientists are exploring nanomaterials that can mitigate the impact of bacterial infections within hospital and health care facilities. ZnO nanoparticles (NPs) exhibit unique antibacterial properties because of its potential to generate reactive oxygen species (ROS) and release of Zn2+in aqueous media. Antibacterial properties of ZnONPs depend on its physiochemical properties such as size, morphology and surface defects. ZnONPs are effective against bacterial pathogens such as Aspergillus niger, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas vulgaris, Escherichia coli, Candida albicans and Pseudomonas aeruginosa. This review discussed ZnONPs antibacterial mechanisms and its limitations. Update on frequent techniques used in synthesis of undoped and transition metal (TM) doped ZnONPs were provided. Furthermore, the influence of TM doping on the physiochemical properties ZnONPs as well as their impact on its antibacterial mechanisms were also discussed.

Small Hydropower as a Source of Clean and Local Energy in Nigeria: Prospects and Challenges

Abstract: Just as the need for air is inevitable in our everyday existence, energy is consumed in every sector of any nation at every second. Due to the increase in technological advancements and high population growth rate, among other factors, in the world today, there is the need for more energy than in the past centuries. Therefore, one of the best solutions to address this issue of increasing energy demand in Nigeria is harnessing the enormous small hydropower potential sites that is scattered in many parts of the nation. It is unfortunate that out of over 278 potential sites with 734.3 MW potential capacity, Nigeria has yet explored only 37.0MW. It is noteworthy that the SHP scheme has its own challenges especially in developing nations. For instance, it is reported to have high capital investment. This challenge is offset by the fact that it incurs little operation and maintenance costs. It has very high payback ratio which proves it to be a cheap source of energy. Furthermore, it is a clean and local source of energy that is reliable, affordable and predictable due to the consistency in the availability of water in rivers and its ability to be integrated with existing projects. Such multi-purpose schemes that can be integrated with the SHP schemes while guaranteeing its primary function include; irrigation network, drinking water reservoirs, wastewater treatment plants, etc. It also has the potential to create many job opportunities and also enhance women development.

The effect of physicochemical parameters on the abundance of zooplankton of River Adada, Enugu, Nigeria

Abstract: Because of the pivotal role of zooplankton in most aquatic ecosystems; there is constant need to explore the effect of stressors (such as physicochemical properties of freshwater) on their abundance. We documented the effect of temperature, pH, turbidity, dissolved oxygen (DO), nitrate (NO3-), and phosphate (PO4³-) on the abundance of zooplankton of the River Adada, Nigeria. Using a manual pump, zooplankton were collected from three strategic stations from January to April (dry season) and June to September (rainy season). A total of 2,219 (dry = 945; rainy = 1,274) zooplankton occurred in the following descending order of abundance: copepods < rotifers < cladocerans < ostracods < insect larva. Whereas based on species number, cladocerans (n = 10) < copepods (n = 8) < rotifers (n = 7) < insect larva (n = 4) < ostracods (n = 2) occurred in this descending order. The downstream (station C) had more zooplankton (dry = 427; rainy = 391), followed by the mid-stream (station B; dry = 216; rainy = 591) and upstream (station A; dry = 302; rainy = 292). There was also a significant (P < 0.05) joint interactive effect of thermal condition on turbidity, pH, DO, PO4³- and NO3- to influence zooplankton abundance. Indicating that temperature is an important factor determining the assemblage of zooplankton in freshwater. Nevertheless, to assure an accurate evaluation of the effect of physicochemical parameters on zooplankton abundance in freshwater, future studies should include extended study periods and make use of more sophisticated trapping technique that would ensure the collection of a larger sample size with more species of zooplankton.

Identifying potential natural inhibitors of Brucella melitensis Methionyl-tRNA synthetase through an in-silico approach

Abstract: Brucellosis is an infectious disease caused by bacteria of the genus Brucella. Although it is the most common zoonosis worldwide, there are increasing reports of drug resistance and cases of relapse after long term treatment with the existing drugs of choice. This study therefore aims at identifying possible natural inhibitors of Brucella melitensis Methionyl-tRNA synthetase through an in-silico approach.Using PyRx 0.8 virtual screening software, the target was docked against a library of natural compounds obtained from edible African plants. The compound, 2-({3-[(3,5-dichlorobenzyl) amino] propyl} amino) quinolin-4(1H)-one (OOU) which is a co-crystallized ligand with the target was used as the reference compound. Screening of the molecular descriptors of the compounds for bioavailability, pharmacokinetic properties, and bioactivity was performed using the SWISSADME, pkCSM, and Molinspiration web servers respectively. The Fpocket and PLIP webservers were used to perform the analyses of the binding pockets and the protein ligand interactions. Analysis of the time-resolved trajectories of the Apo and Holo forms of the target was performed using the Galaxy and MDWeb servers.The lead compounds, Strophanthidin and Isopteropodin are present in Corchorus olitorius and Uncaria tomentosa (Cat's-claw) plants respectively. Isopteropodin had a binding affinity score of -8.9 kcal / ml with the target and had 17 anti-correlating residues in Pocket 1 after molecular dynamics simulation. The complex formed by Isopteropodin and the target had a total RMSD of 4.408 and a total RMSF of 9.8067. However, Strophanthidin formed 3 hydrogen bonds with the target at ILE21, GLY262 and LEU294, and induced a total RMSF of 5.4541 at Pocket 1.Overall, Isopteropodin and Strophanthidin were found to be better drug candidates than OOU and they showed potentials to inhibit the Brucella melitensis Methionyl-tRNA synthetase at Pocket 1, hence abilities to treat brucellosis. In-vivo and in-vitro investigations are needed to further evaluate the efficacy and toxicity of the lead compounds.

Prevalence, pattern and predictors of work-related musculoskeletal disorders among oil workers in Nigeria

Abstract: Work-related musculoskeletal disorders (WMSD) account for a loss of GDP in most countries. The oil sector is the largest and most economically relevant industry in Nigeria, yet the impact of WMSD on workers in this industry is unknown.To assess the prevalence, pattern and predictors of WMSD among oil workers in Nigeria.This exploratory study was conducted in oil producing companies in Nigeria. Nordic Musculoskeletal Questionnaire was used to assess WMSD, while risk factors and demographic variables were obtained through an interview. Obtained data were analysed using descriptive statistics, Chi-square and logistic regression at α=0.05RESULTS:A total of 198 (138 male, 60 female) oil workers aged 40.3±10.1 years participated in this study. The prevalence of WMSD was 88.8%, and was most common around the low-back (51.5%), and neck (44.4%) regions. There was a significant association between WMSD and each of duration of service (X2 = 45.44, p = 0.020), awkward neck postures at work (X2 = 12.46, p = 0.006), inadequate training on injury prevention (X2 = 11.98, p = 0.007), and continuing to work while feeling discomfort (X2 = 10.83, p = 0.013). Post-hoc analysis revealed that being a male oil worker (OR = 1.17, p = 0.037) and continuing to work while feeling discomfort or pain (OR = 2.23, p = 0.048) were the significant predictors of WMSD.Approximately nine in every ten oil workers in Nigeria have a WMSD. Male gender and work persistence amidst discomfort or pain are the predictors of WMSD among oil workers in Nigeria. Ergonomics training and evaluation programme is recommended for workers in this industry.

Estimating emissions from open-burning of uncollected municipal solid waste in Nigeria

Abstract: <abstract> <p>Open-burning of municipal solid waste (MSW) is very common in Nigeria. Hence, this work estimated the emissions (greenhouse gases and others) from open-burning of uncollected MSW in Nigeria. The parameters (secondary data) used for the estimations were obtained from pertinent literature of MSW generation rate in Nigeria, level of uncollected MSW subjected to burning in Nigeria, oxidation/burning efficiency and others, 80.6% of wastes generated in Nigeria are combustibles. The National Bureau of Statistics showed that 52% of Nigerians lives in urban areas in the year 2020. With an annual mean growth rate of 2.62% between 2006–2020 (World Bank data), the urban population of Nigeria was estimated at 104, 885, 855 in 2020. The estimation for the year 2020 shows that the MSW generated by the urban population of Nigeria ranges from 16.8–25.3 million tons. With burning/oxidation efficiency ($\eta $) of 0.58, between 2.4–3.7 million tons of the uncollected wastes are open-burned. This represents 14.7% of the total MSW generated in Nigeria for the year. IPCC guidelines show that only fossil-carbon wastes are climate-relevant for CO₂ emissions. Our estimation shows that 14.3% of the MSW generated in Nigeria contain fossil carbon. The total emissions for the three GHGs–carbon dioxide, methane and nitrogen oxides were between 798 to 1, 197 kilotons of CO₂-eq per year. Other emissions associated with open-burning of MSW was also estimated using their default emission factor. The findings suggest the urgent need for the country to transition to proper waste management system, which will include improved collection and disposal to sanitary landfills, to protect public health and the environment.</p> </abstract>

Has bank credit really impacted agricultural productivity in the Central African Economic and Monetary Community?

Abstract: Purpose This paper investigates the impact of bank credit on agricultural productivity in the Central African Economic and Monetary Community (CEMAC) from 1990 to 2019. Studies’ results on the impact of bank credit on agricultural productivity are not conclusive. The studies demonstrate diverse outcomes which are debatable. The results are conflicting. Design/methodology/approach Agricultural value added (AGRVA) to the gross domestic product (GDP) proxies agricultural productivity while domestic credit to the private sector by banks (DCPSB), broad money supply, land, inflation (INF), physical capital (PHKAP) and labour supply are explanatory variables. The autoregressive distributed lag technique is utilized. Findings The co-integration test results show a long-run co-integration among the variables. The findings disclose that DCPSB, land and PHKAP impact positively on the AGRVA. Broad money supply, INF and labour impact negatively on the AGRVA to the GDP. Research limitations/implications The results suggest that the CEMAC governments should encourage effective ways to increase bank credit flow to private enterprises in the agricultural sector through efficient bank's intermediation. Practical implications The governments should create more agricultural banks and improve the operation of existing ones to ensure direct credit to agricultural activities. The Bank of Central African Economic and Monetary Community should apply aggressive policy which eliminates all the bottlenecks undermining credit flow to the private sector in mutualism with agricultural productivity. Social implications The commercial banks should give more credit to private sector to mutually benefit the agricultural sector and the banking sector. The governments of the CEMAC economies should expand funding into the capital market which considerably boosts agricultural productivity. Originality/value Studies’ results on the impact of bank credit on agricultural productivity are not conclusive. The studies demonstrate diverse outcomes which are debatable. The results are conflicting; some reveal positive impacts, some show negative impacts and others indicate U-shape behaviour. Hence, research is required to fill the lacuna.

Variation in Maize Grain Yield Indices When Exposed to Combined Heat and Water Stress Conditions under Different Soil Amendments

Abstract: Increased yield can be achieved by optimising the growth environment, improving the plant gene pool, or a combination of the two. This study’s objective was to evaluate the effect of combined heat and water stress (CHWS) on maize yield, grown in various soil conditions. The experimental design was a four-replicated 3 × 3 × 2 × 3 factorial in a completely randomized design. Three water stress levels, three soil amendments, two soil textural types, and three drought-tolerant maize varieties were combined to create 54 treatment interactions. The result showed that as the severity of the water stress increased, the yield decreased. The near terminal water stress reduced cob weight, grain weight, and grain number by 96, 97, and 97%, respectively. The maize varieties were ranked WE5323 ≥ ZM1523 > WE3128 in terms of average performance and stability. Under heat and moderate water stress, the poultry manure amendment performed well for WE5323 and ZM1523, while the mineral fertilizer amendment performed best for WE3128. Compared to the inorganic amendment, the organic had a greater ameliorative capacity for grain yield under CHWS. For improved grain yield under CHWS, farmers are advised to grow WE5323 and ZM1523 with organic amendments. The findings in this study could improve food security strategies for low-income households living in high-stress environments.