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In vitro anthelminthic and anti-inflammatory activities, and GC-MS analysis of methanol and acetone extracts of Mareya micrantha leaves
(Journal of Pharmacognosy and Phytochemistry, 2024-03) Acheampong, Akwasi; Quartey, Emmanuel; Acquaye, Maud Adoley; Naazo, Abdulai A; Baah, Kennedy Ameyaw; Amankwaa, Lydia Tima; Buah, Patrick; Frimpong, Silas Ofori; 0000-0003-2481-1126
Mareya micrantha, a medicinal plant, is used to treat pains, wounds, worm infestations and gastrointestinal disorders. The aim of this research was to investigate the anthelmintic and anti-inflammatory properties of the methanol and acetone extracts of Mareya micrantha leaves. Phytochemical screening was performed using standard methods with GC-MS used for the identification of the phytochemicals. Egg albumen denaturation was used for the determination of the anti-inflammatory (in vitro) activities of the extracts. Anthelmintic activity (in vitro) of the extracts was investigated against Millsonia ghanensis. Phytochemical investigation revealed the presence of phenols, terpenoids, polyphenols, flavonoids, tannins, steroids, saponins, and glycosides. Twenty phytochemicals, most of which have known bioactivities, were identified for each extract with five being common to them, and they are n-hexadecanoic acid, Tributyl acetyl citrate, hexadecanoic acid methyl ester, 3, 7, 11, 15-tetramethyl-2-hexadecen-1-ol, and 2, 2, 4-trimethyl-3-(3, 8, 12, 16-tetramethyl-heptadeca-3, 7, 11, 15-tetraethyl)-cyclohexanol. The extracts had anti-inflammatory activity. The anthelmintic activity of the extracts was significantly higher than mebendazole-treated helminths. The outcome of this study points to the fact that Mareya micrantha could be exploited as a source of potential drug candidates against helminthic and microbial infection as well as inflammation and oxidative stress.
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In vitro antimicrobial, antioxidant, and anti-helminthic activities and GC-MS analysis of fractions of the leaves of Aspilia silphioides
(Journal of Pharmacognosy and Phytochemistry, 2024-08) Acheampong, Akwasi; Buah, Patrick; Oti-Boakye, Adolf; 0000-0003-2481-1126
The leaves of Aspilia silphioides are effective for wound healing, stomach aches, headaches, worm infestations, and birth control. The purpose of this study was to determine the phytochemical components of the bulked fractions of A. silphioides and evaluate the antimicrobial, anti-helminthic, and antioxidant activities of various solvent fractions. Standard methods were employed for the phytochemical screening. The methanol extract was fractionated and bulked to obtain bulked fractions A, B, C and D. The bulked fractions contained phytoconstituents including tannins, flavonoids, phenolics, steroids, polyphenols, phytosterols, and terpenoids. GC-MS analysis of the fractions revealed various compounds including 9-octadecenamide, O-methyl- (+)-a-tocopherol, and a-Amyrin as being present in the bulked fractions. The IC50 of the fractions B, C, D and the reference drug with regards to the DPPH scavenging activity were 15.47±0.61 μg/mL, 28.16 ±0.61 μg/mL, 19.62 ±0.61 μg/mL, and 40.29±0.62 μg/mL respectively. At 20 μg/mL, the paralysis and death time for both fraction C and Mebendazole drug were 19.45±0.15 min, 31.60±18 min, and 52.06±2.89min, 82.03±47.37min respectively. The minimum inhibitory concentrations of fractions A, C, and D against the tested organisms were 25±0.01-50±0.01 mg/mL, 6.25±0.02-25±0.01 mg/mL, and 12.5±0.01-25±0.01 mg/mL respectively. The minimum bactericidal concentrations of fractions A, C, and D against the tested organisms were 25±0.01-50±0.01 mg/mL, 6.25±0.01-25±0.01 mg/mL, and 12.5±0.01-50±0.02 mg/mL respectively. The bulked fractions of the methanol extracts of Aspilia silphioides possess antioxidant, anti-helminthic, and antimicrobial activities.
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Repellency Potential, Chemical Constituents of Ocimum Plant Essential Oils, and Their Headspace Volatiles against Anopheles gambiae s. s., Malaria Vector
(Hindawi, 2023-04) Acheampong, Akwasi; Osei-Owusu, Jonathan; Heve, William K.; Aidoo, Owusu Fordjour; Opoku, Maxwell Jnr; Apau, Joseph; Dadzie, Kodwo Ninsin; Vigbedor, Bright Yaw; Awuah-Mensah, Kwaafo Akoto; Appiah, Margaret; Birkett, Michael; Hooper, Antony; 0000-0003-2481-1126
African malaria mosquitoes (Anopheles gambiae sensu stricto) transmit a malaria parasite (Plasmodium falciparum) to humans. )ecurrent control strategies for the vector have mainly focussed on synthetic products, which negatively impact the environment and human health. Given the potential use of environmentally friendly plant-derived volatiles as a control, this work aims to examine and compare the repellency potential of essential oils and headspace volatiles from Ocimum gratissimum, Ocimum tenui2orum, and Ocimum basilicum and their chemical compositions. )e repellency potential and chemical composition of the plants were achieved by using the protected arm-in-cage method and gas chromatography-mass spectrometry (GC-MS) analysis. Among the three Ocimum species, both the essential oils and the headspace volatiles from O. tenui2orum achieved the longest repellency time lengths of 90–120 minutes. One hundred and one (101) chemical constituents were identi6ed in the headspace volatiles of the three Ocimum spp. Nonetheless, (−)-camphor, (E)-c-bisabolene, terpinolene, 4-chamigrene, cubedol, (E)-farnesol, germacrene D-4-ol, viridi9orol, c-eudesmol, tetracyclo [6.3.2.0 (2,5).0(1,8)] tridecan-9-ol, 4,4-dimethyl, 5-eudesmol, isolongifolol, and endo-borneol were unique only to O. tenui2orum headspace volatiles. Either essential oils or headspace volatiles from O. tenui2orum could o>er longer protection time length to humans against An. gambiae. )ough 6eld studies are needed to assess the complementarity between the chemical constituents in the headspace volatiles of O. tenui2orum, our observations provide a foundation for developing e>ective repellents against An. gambiae.
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A Two-Phase Method for Solving Transportation Models with Prohibited Routes
(Pakistan Journal of Statistics and Operation Research, 2022) Owusu-Ansah, Emmanuel; Ackora-Prah, Joseph; Acheson, Valentine; Barnes, Benedict; Takyi, Ishmael
The Transportation Problem (TP) is a mathematical optimization technique which regulates the flow of items along routes by adopting an optimum guiding principle to the total shipping cost. However, instances including road hazards, traffic regulations, road construction and unexpected floods sometimes arise in transportation to ban shipments via certain routes. In formulating the TPs, potential prohibited routes are assigned a large penalty cost, M; to prevent their presence in the model solution. The arbitrary usage of the big M as a remedy for this interdiction does not go well with a good solution. In this paper, a two-phase method is proposed to solve a TP with prohibited routes. The first phase is formulated as an All-Pairs Least Cost Problem (APLCP) which assigns respectively a non-discretionary penalty costM? ij M to each of n prohibited routes present using the Floyd’s method. At phase two, the new penalty values are substituted into the original problem respectively and the resulting model is solved using the transportation algorithm. The results show that, setting this modified penalty cost (M?) logically presents a good solution. Therefore, the discretionary usage of the M 1 is not a guarantee for good model solutions. The modified cost M? M so attained in the sample model, is relatively less than the Big M( 1) and gives a good solution which makes the method reliable.
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A Proposed Method for Finding Initial Solutions to Transportation Problems
(Pakistan Journal of Statistics and Operation Research, 2023) Owusu-Ansah, Emmanuel; Acheson, Valentine; Ackora-Prah, Joseph; Nkrumah, Seth K
The Transportation Model (TM) in the application of Linear Programming (LP) is very useful in optimal distribution of goods. This paper focuses on finding Initial Basic Feasible Solutions (IBFS) to TMs hence, proposing a Demand- Based Allocation Method (DBAM) to solve the problem. This unprecedented proposal goes in contrast to the Cost- Based Resource Allocations (CBRA) associated with existing methods (including North-west Corner Rule, Least Cost Method and Vogel’s Approximation Method) which select decision variable before choosing demand and supply constraints. The proposed ‘DBAM’ on page 66 is implemented in MATLAB and has the ability to solve large-scale transportation problems to meet industrial needs. A sample of five (5) examples are presented to evaluate efficiency of the method. Initial Basic Feasible Solutions drawn from the study are of higher accuracy and will rapidly converge to optima in less iterations. The comparative results also showed that the DBAM outperforms other methods under this study which qualifies it as one of the best methods to solve industrial TMs.
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A systematic framework for dynamic nodal vulnerability assessment of water distribution networks based on multilayer networks
(Elsevier, 2021-11) Owusu-Ansah, Emmanuel; Tornyeviadzi, Hoese Michel; Mohammed, Hadi; Seidu, Razak
Nodal demands vary throughout the day, as such any vulnerability analysis based on static networks, which considers daily average demands cannot realistically represent the criticality of nodes in the network. This study presents a systematic framework, which couples multilayer networks, structural reducibility and a Demand Adjusted Vulnerability Measure for dynamic nodal vulnerability assessment of water distribution networks (WDNs) under extended period simulation. Within this framework, we present the novel idea of characterizing the dynamics of WDNs with multi-slice networks, which captures the state of the network within a predefined temporal window taking into consideration the directional flow in pipes and the operational status of pumps, valves etc. Using a benchmark WDN, Net 3, as a case study we have demonstrated the importance of demand variations and operational status of various components, no matter how minuscule their operational time, on nodal vulnerability assessment in WDNs. The results indicated that the framework evaluates the criticality of all types of nodes, even intermediary nodes with zero base demand, within any temporal window much more realistically than conventional vulnerability analysis methods based on single (static) networks. Structural reducibility unearthed correlations between the operational status of source nodes and pumps on the general dynamics of the distribution system. The multilayer framework opens a new frontier in vulnerability analysis of WDNs and could serve as a tool for stakeholders in accessing node criticality, impact of various failure scenarios and optimal scheduling of maintenance routines.
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ARTIFICIAL NEURAL NETWORK MODEL FOR LOW STRENGTH RC BEAM SHEAR CAPACITY
(Journal of Science and Technology, 2012-08) Owusu-Ansah, Emmanuel; Afrifa, R. Owusu; Adom-Asamoah, M.
This research was to investigate how the shear strength prediction of low strength reinforced concrete beams will improve under an ANN model. An existing database of 310 reinforced concrete beams without web reinforcement was divided into three sets of training, validation and testing. A total of 224 different architectural networks were tried, considering networks with one hidden layer as well as two hidden layers. Error measures of strength ratios were used to select the best ANN model which was then compared with 3 conventional design code equations in predicting the shear strength of 26 low strength RC beams. Even though the ANN was the most accurate, it was less conservative compared with the design code equations. A model reduction factor based on the characteristic strength concept is derived in this research and used to modify the ANN output. The modified ANN model is conservative in terms of safety and economy but not overly conservative as the conventional design equations. The procedure has been automated such that when new experimental sets are added to the database, the model can be updated and a new model could be developed.