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1, 3-Dipolar cycloaddition reactions of selected 1,3-dipoles with 7-isopropylidenenorbornadiene and follow-up thermolytic cleavage: Acomputational study
(Elsevier Inc., 2019-08-08) Arhin, Grace; Adams, Anita Houston; Opoku, Ernest; Tia, Richard; Adei, Evans
The mechanism, regio-, stereo-, and enantio-selectivities of the 1,3-dipolar cycloaddition reactions of7-isopropylidenenorbornadiene (DENBD) with nitrones and azides to form pharmaceutically relevantisoxazolidine and triazole analogues have been studied computationally at the M06/6-31G(d), 6-31G(d,p), 6-311G(d,p), 6e311þþG(d,p) and M06-2X/6-31G(d) levels of theory. In the reactions of DENBDwith phenyl nitrones, the cycloaddition steps have low activation barriers, with the highest being 16 kcal/mol; and the Diels-Alder cycloreversion steps have generally high barriers, with the lowest being 20 kcal/mol, suggesting that the isolable products in these reactions are the bicyclic isoxazolidine cycloadductsand not the thermolytic products. This is in contrast to the reactions of DENBD with phenyl azide wherethe isolable products are predicted to be the thermolytic products since the Diels-Alder cycloreversionsteps had relatively lower activation barriers. Electron-donating substituents on the dipolarophile sub-strate favour attack of the nitrone on the least hindered side of the DENBD substrate while electron-withdrawing substituents on the dipolarophile substrate favour attack on the more hindered side ofthe DENBD, indicating that site-selectivity is affected by nature of substituents. Global reactivity indicescalculations are in good agreement with the activation barriers obtained. Analysis of the electrophilic(PþKÞand nucleophilic (P KÞParr functions at the reactive centres reveal that the cycloaddition occursbetween atoms with the largest Mulliken and NBO atomic spin densities which agrees well with theenergetic trends and the experimental product outcomes.
[3 + 2] Versus [2 + 2] addition: A density functional theory study on the mechanistic aspects of transition-metal-assisted formation of 1,2-dinitrosoalkanes
(Hindawi Publishing Corporation, 2016-11-21) Opoku, Ernest; Tia, Richard; Adei, Evans
The pathways for the transition metal-assisted formation of 1,2-dinitrosoalkane complexes of cobalt and its congeners, have beenstudied using DFT/M06 with the LACVP∗basis set. The activation barriers for the one-step [3 + 2] addition pathway for theformation of 1,2-dinitrosoalkanes, proposed by Bergman and Becker, are generally low compared to the activation barriers for the[2 + 2] addition to form an intermediate, which is the first of the two-step pathway proposed by Rapp ́e and Upton, which are veryhigh. The barriers of the rearrangement of the Rapp ́e intermediates to the final products by reductive elimination involving thesecond metal-nitrogen𝜋-bond are also very high. The reactions of the Co complexes have lower activation barriers than Rh andIr complexes. The barriers of the reactions involving olefins with electron-donating groups are generally lower compared to thereactions of the parent (unsubstituted) ethylene while the activation barriers for reactions of olefins with electron-withdrawinggroups are generally higher compared to the parent (unsubstituted) ethylene. The one-step [3 + 2] pathway remains the mostfavoured irrespective of the metal centre or the nature of the olefin. The mechanism of the reaction is therefore settled in favour ofthe [3 + 2] addition pathway.
3-Monochloropropandiol and glycidyl esters in heat-processed oil-based food products: Exposure and risk
(Applied Food Research, 2024-06) Yabani, Daniel Sitsofe; Ofosu, Isaac Williams; Ankar-Brewoo, Gloria Mathanda; Lutterodt, Herman Erick; 0000-0001-5442-6654; 0000-0002-9553-0834; 0000-0001-8574-3409; 0000-0001-7015-7597
Fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPDE) and glycidol (GE) are potentially harmful heatinduced contaminants produced during food processing. In this study, 100 heat-treated oil-based food samples covering fried, smoked, grilled, and baked food groups were collected in Koforidua, Ghana and analysed for the two esters using gas chromatography-mass spectrometry. The dietary exposures were estimated by a probabilistic approach using Monte Carlo Simulation. Levels of 3-MCPDE and GE in the foods ranged from
A blockchain-based certificateless public key signature scheme for vehicle-to-infrastructure communication in VANETs
(Journal of Systems Architecture, 2019-10) Ali, Ikram; Gervais, Mwitende; Ahene, Emmanuel; Li, Fagen; 0000-0002-2893-4249; 0000-0002-0810-1055
Vehicular Ad Hoc Networks (VANETs) have been developing based on the state-of-art in wireless network communication technologies to improve traffic on roads. However, there are some threats to security and privacy due to the open wireless environment in VANETs and the high speed of vehicles. The uthentication of messages related to traffic which are exchanged with the vehicles and the Road-Side Unit (RSU) is considered one of the most VANETs necessary security requirements. In this context, several schemes have been designed to secure the traffic-related messages in VANETs. However, these schemes suffer from high computational costs in signatures’ verification. To minimize the computational cost of signature generation and verification, we propose an efficient Certificateless Public Key Signature (CL-PKS) scheme using bilinear pairing to provide conditional privacy-preserving authentication for Vehicle-To-Infrastructure (V2I) communication in VANETs. The CL-PKS scheme supports batch signature verification and aggregate signature verification functions to speed up verification process. In addition to this, we include blockchain to our CL-PKS scheme to implement revocation transparency of pseudo-identities efficiently before verifying the signatures. Furthermore, this scheme provides security proof and protection against different types of attacks. The proposed scheme incurs lower computational cost as compared to that incurred by existing schemes.
A comparative study of Ghanaian propolis extracts: Chemometric analysis of the chromatographic profile, antioxidant, and hypoglycemic potential and identification of active constituents
(Scientific African, 2023-11) Amankwaah, Frederick; Addotey, John Nii; Orman, Emmanuel; Adosraku, Reimmel; Amponsah, Isaac Kingsley; 0000-0002-4372-3992
Diabetes is a disease characterized by high post-prandial glucose levels, which lead to other complications such as peripheral end organ damage. The use of enzyme inhibitors in the management of Type-2 diabetes ensure the control of blood glucose levels via the control of carbohydrate metabolism. The use of standard agents such as acarbose is associated with unwanted side effects hence the need to investigate other sources of antihyperglycemic agents. Propolis, a natural substance from bees, possesses diverse biological activities including antioxidant, antimicrobial and antidiabetic properties. However, the phytochemical content of propolis and its extracts may vary depending on the geographical area, the solvent of extraction and type of bees. This study represents the first attempt to compare different extracts of propolis from the same source in sub-Saharan Africa. In this study, the effect of solvent and source of Ghanaian propolis on parameters such as the total phenolic and flavonoid contents, chromatographic profile, antioxidant and α-amylase inhibitory effects were investigated with the aim of identifying and characterizing the most promising extract, which could be of direct or indirect benefit in the management of Type-2 diabetes. Combinations of water, ethanol-water and ethanol extracts were prepared from propolis from three regions. Phytochemical screening was performed on the extracts after which the Folin Ciocalteu method and aluminum chloride colorimetric assay were used to estimate the total phenolic and flavonoid contents respectively. Antioxidant potential of extracts was estimated using DPPH and phosphomolybdenum assays. In-vitro α-amylase inhibition assay was used to investigate hypoglycemic effect of the extracts. Statistical tools such as ANOVA, principal component analysis, hierarchical cluster analysis employed to determine sources of variations within the data obtained, to classify the extracts based on activity and to predict the most effective extract. This extract was then subjected to UHPLC-Q-TOF MS/MS and GC–MS techniques to characterize the constituents. Chemometric analysis of the data obtained showed that the variations in the data could be explained by both propolis source and extraction solvent. Though ethanol extracts generally contained more constituents, the more notable activities were in the ethanol-water extracts. The ethanol-water extract of Bono East propolis (EWBE) was the most potent DPPH radical scavenger (IC50 of 149.37 ± 2.90 µg/mL as compared to 116.60 ± 0.93 µg/mL GAE standard). It was also one of the three extracts which were more potent than acarbose (369.89 µg/mL) in the α-amylase inhibition assay. The predominant constituents from the LC-MS dereplication of EWBE were caffeic acid and flavonoid derivatives whilst 5,5-dimethyl-1-oxa-5 silacyclononanone-9 was the most significant active constituent identified through the GC–MS analysis. The identified constituents are known to have strong antioxidant and antidiabetic properties. The effects of source and solvent of extraction on the biological and physicochemical properties of propolis in Ghana have been quantified using statistical tools. The combined biological effects of propolis suggest a possible role in their usage in the management of type-2-diabetes and its related complications. Ethanol-water extracts were the most promising with EWBE showing the strongest antihyperglycemic activity. Such extracts represent leads towards further research into toxicity and formulation in order to develop safe and useful products for the management of type-2 diabetes.
A Comparative Study of the Epidemiology of Treponemal Infection in the Volta and Oti Regions of Ghana: A Five-Year Multisite Parallel Population-Based Analysis vis-à-vis the Sentinel Survey
(Hindawi, 2021) Yao Lokpo Sylvester; Owusu-Dabo Ellis; Gameli Deku John; Ndudiri Orish Verner ....et al; Kye-Duodu Gideon; 0000-0003-4232-4292
Treponemal infections can be blood-borne with great public health consequences. This study is aimed at comparatively describing the five-year (2013-2017) regional epidemiology of treponemal infection using pregnant women in the sentinel survey and apparently healthy blood donors as a proxy for the general population at four sentinel sites in the Volta and Oti Regions of Ghana. We analyzed retrospective data from 17,744 prospective blood donors aged 18 to 58 years and 7,817 pregnant women in a sentinel survey with ages from 15 to 49 years at Hohoe, Ho, Tongu, and Krachi West sentinel sites in the Volta and Oti Regions. Laboratory data extracted include variables such as age, gender, date of blood donation, and Treponema pallidum chromatographic immunoassay results from the blood banks of the four study sites. The five-year treponemal infection rate among the pregnant women in the sentinel survey and prospective blood donors was 0.79% and 2.38%, respectively. Site-specific infection rate for population-based/sentinel survey was 4.6%/1.1%, 2.0%/0.5%, 1.3%/1.1, and 1.2%/0.3% for Hohoe, Ho, Krachi West, and Tongu, respectively. Significant gender disparity in Treponemal infection rate exists with a male preponderance. The regional infection rate in the sentinel survey is lower compared to the general population. Therefore, the use of pregnant women as a proxy for population estimates could underestimate the burden in the study jurisdiction.
A critical review of carbonate reservoir wettability modification during low salinity waterflooding
(Petroleum, 2022-01-12) Sagbana, Perekaboere Ivy; Sarkodie, Kwame; Nkrumah, Wilberforce Aggrey
The nature of carbonate reservoirs promotes the adsorption of oil onto the rock surface hence making oil recovery a challenge even with the interventions of varied chemical EOR methods. Recently, low salinity water flooding has become of great interest since it is cost-effective and environmentally friendly. Although low salinity waterflooding has been highly investigated in sandstone reservoirs, it is not the same for carbonate reservoirs due to its complexities. Nonetheless, it has been proposed as a favourable technique to mobilise the trapped oil in carbonate reservoirs. Wettability alteration is regarded as the most accepted mechanism for low salinity flooding but has not been well understood making field scale applications doubtful. In this paper, we present a detailed review of the wettability alteration mechanisms in carbonate reservoirs during low salinity waterflooding. Parameters influencing wettability alteration in carbonates and the interactions that occur at the rock/brine/oil interface are also presented. The different methods utilised for wettability measurements during low salinity waterflooding are also reviewed including their drawbacks and advantages and recommendations. This will provide an improved understanding of the low salinity flooding application in carbonate reservoirs.
A cross‑sectional study on risk factors for infection with Parvovirus B19 and the association with anaemia in a febrile paediatric population inGhana
(Springer Nature, 2020) Herr Wiebke; Hogan Benedikt; Owusu-Dabo Ellis; Sarpong Nimako; Gyau Kennedy....et all; 0000-0003-4232-4292
Parvovirus B19 (B19V) occurs globally and can cause severe anaemia. The role of co-infections with Plasmodium falciparum (P. falciparum) has been controversially discussed. The study aimed to determine prevalence and severity of B19V infection, and the effect of co-infections on the risk for anaemia. Between November 2013 and April 2015 a total of 1186 hospital visits of children with fever admitted to a hospital in Ghana were recorded. Malaria, B19V and additional diagnostics for fever causes were performed. Recent B19V infection was defined as PCR and/or IgM positivity. Risk factors for a B19V infection and for anaemia were analysed. The prevalence of anaemia was compared between children with/without B19V infection, stratified for the presence of malaria. B19V IgM/PCR was positive in 6.4% (n = 76; 40 IgM + , 30 PCR + , 6 IgM + and PCR +). Among the B19V cases 60.5% had a simultaneous P. falciparum infection. B19V IgM positivity but not PCR positivity was associated with moderate-severe anaemia (OR = 2.6; 95%-CI: 1.3–5.3; P < 0.01 vs. OR = 0.9; 95%-CI: 0.4–1.8; P = 0.70). P. falciparum and IgM positive B19V infection were independent risk factors for anaemia with no evidence of effect modification. Our data show a significant association between B19V infection, defined as IgM but not PCR positivity, and moderate-severe anaemia. A multiplicative effect of B19V and P. falciparum infection was not found.
A formulation of Clausena anisata (Willd.) Hook. f. Ex Benth and Cassia sieberiana DC. alleviates the symptoms associated with osteoarthritis: a single-blind, randomised controlled trial of a traditional Ghanaian remedy
(Springer Open, 2019) Kwesi Prah, Thomford; Yorke, Joseph; Ama Kyeraa, Thomford; Amponsah, Isaac Kingsley; 0000-0002-5229-0340
Background: Clinical validation of herbal medicinal products is important for their widespread acceptance and application. In this single-blind, randomised controlled trial, a traditional Ghanaian herbal medicine formulation with Clausena anisata (Willd.) Hook. f. ex Benth and Cassia sieberiana DC. as ingredients was evaluated for its safety and effectiveness in the management of patients with osteoarthritis. The formulation for the purposes of this study was labelled with the code GC-500. Methods: A total of 57 participants were randomly assigned to receive either this herbal remedy, GC-500, or the control treatment of diclofenac. Subjects were then followed up for a period of 8 weeks using a modified Graded Chronic Pain Scale (GCPS) for their efficacy assessments. The control treatment comprised 13 subjects and the GC 500 group 44 subjects. Results: Upon completion of the study, 28 (63.63%) subjects in the GC-500 group attained the primary outcome, (GCPS of Grade 0) compared to 5 (38.46%) subjects in the control group. Improvement in disease indicators such as characteristic pain intensity, disability score and disability days was comparable between the GC-500 and diclofenac. Intensity of pain reduced after 8 weeks of treatment; disability score and disability days also declined indicating an improvement in the quality of life of subjects. GC-500 was also shown to be safe for human use. Conclusion: The herbal medicine formulation GC-500, provides a credible treatment option for managing the pain associated with osteoarthritis.
A gist on an obscure neoplasm in Ghana: gastrointestinal stromal tumours
(BMC Publisher, 2023) Yorke, Joseph; Brenu, Samuel Gyasi; Awoonor‑Williams, Ronald; Tabiri, Stephen; Seidu, Anwar Sadat; 0000-0002-5229-0340
Background Gastrointestinal Stromal Tumour is a rare but potentially curable tumour of the gastrointestinal tract accounting for up to 1% of all gastrointestinal tumours. The discovery of Imatinib mesylate, a novel tyrosine kinase inhibitor has improved the chances even for unresectable, recurrent, or metastatic diseases. Methods This study sought to document the clinical and pathological characteristics of GISTs from two tertiary hos‑ pitals in Ghana that have undergone immunohistochemistry confrmation between 2014 and 2021. Results The median age of the subjects was 50 years with most of them (28.0%) being above 61 years. There were more females than males (64.0% vs. 36.0%). Abdominal mass and abdominal pain made up the majority of the clinical presentations. The majority of the subjects had partial gastrectomy (32.0%) which was followed by wedge resec‑ tion (28.0%). Appendectomy and sleeve gastrectomy were the least performed procedures (8% each). Four of the 25 patients (16.0%) had resections of involved contiguous organs done with splenectomy being the most common procedure. The majority of GISTs were found in the stomach (68.0%) followed by the appendix (12.0%) and small bowel (12.0%). Gastrointestinal bleeding (55.8%) and abdominal pain (38.5%) were the most reported symptoms. Free resection margins were observed in 84.0% of the subjects and only 3/25 (12.0%) experienced tumour recurrence. Conclusion GIST is a potentially curable tumour that once was obscure but currently gaining popularity. Surgical resection ofers the hope of a cure for localized disease while targeted therapies is a viable option for recurrent, meta‑ static, or unresectable tumours.
A hybrid forecasting technique for infection and death from the mpox virus.
(Digital Health, 2023) Iftikhar, Hasnain; Daniyal, Muhammad; Quresh, Moiz; Tawaiah, Kassim; Ansah, Richard Kwame; Afriyie, Jonathan Kwaku; 0000-0001-6997-7969
Objectives: The rising of new cases and death counts from the mpox virus (MPV) is alarming. In order to mitigate the impact of the MPV it is essential to have information of the virus’s future position using more precise time series and stochastic models. In this present study, a hybrid forecasting system has been developed for new cases and death counts for MPV infection using the world daily cumulative confirmed and death series. Methods: The original cumulative series was decomposed into new two subseries, such as a trend component and a stochastic series using the Hodrick–Prescott filter. To assess the efficacy of the proposed models, a comparative analysis with several widely recognized benchmark models, including auto-regressive (AR) model, auto-regressive moving average (ARMA) model, non-parametric auto-regressive (NPAR) model and artificial neural network (ANN), was performed. Results: The introduction of two novel hybrid models, HPF1 1 and HPF4 3, which demonstrated superior performance compared to all other models, as evidenced by their remarkable results in key performance indicators such as root mean square error (RMSE), mean absolute error (MAE) and mean absolute percentage error (MAPE), is a significant advancement in disease prediction. Conclusion: The new models developed can be implemented in forecasting other diseases in the future. To address the current situation effectively, governments and stakeholders must implement significant changes to ensure strict adherence to standard operating procedures (SOPs) by the public. Given the anticipated continuation of increasing trends in the coming days, these measures are essential for mitigating the impact of the outbreak.
A MATHEMATICAL MODEL OF COVID-19 TRANSMISSION DYNAMICS WITH EFFECTS OF AWARENESS AND VACCINATION PROGRAM
(Journal of Ghana Science Association, 2023-10) Agbata, B.C.; Shior, M.M.; Obeng-Denteh, W.; Omotehinwa, T.O.; Paul, R.V.; Kwabi P. A.; Asante-Mensa, F
This study introduces a deterministic mathematical model for understanding the transmission dynamics of COVID-19, con sidering the influence of vaccination and awareness program, which target susceptible individuals. The model is based on a system of differential equations, resulting in an SVEIR model. Through qualitative analysis, various aspects of the model, such as disease-free equilibrium, endemic equilibrium, basic reproduction number, and local and global stability, were thoroughly explored. The disease-free equilibrium is proven to be both locally and globally stable when R0 < 1, while it ∼becomes unstable when R0 > 1. Simulation results demonstrate that the combination of vaccination and awareness programs emerges as the most effective approach to mitigate the spread of COVID-19 within the population.
A Mixture of Clayton, Gumbel, and Frank Copulas: A Complete Dependence Model
(Hindawi, 2022) Boateng , M. A.; Omari-Sasu, A. Y.; Avuglah, R. K.; Frempong, Nana Kena; 0000-0002-7138-3526
Knowledge of the dependence between random variables is necessary in the area of risk assessment and evaluation. Some of the existing Archimedean copulas, namely the Clayton and the Gumbel copulas, allow for higher correlations on the extreme left and right, respectively. In this study, we use the idea of convex combinations to build a hybrid Clayton–Gumbel–Frank copula that provides all dependence scenarios from existing Archimedean copulas. (e corresponding density and conditional distribution functions of the derived models for two random variables, as well as an estimator for the proportion parameter associated with the proposed model, are also derived. (e results show that the proposed model is able to show any case of dependence by providing coefficients for the upper tail and lower tail dependence.
A Multi-objective Optimization Approach to Workflow Scheduling in Clouds Considering Fault Recovery
(Korean Society for Internet Information, 2016-03) Xu, Heyang; Yang, Bo; Qi, Weiwei; Ahene, Emmanuel; 0000-0002-0810-1055
Workflow scheduling is one of the challenging problems in cloud computing, especially when service reliability is considered. To improve cloud service reliability, fault tolerance techniques such as fault recovery can be employed. Practically, fault recovery has impact on the performance of workflow scheduling. Such impact deserves detailed research. Only few research works on workflow scheduling consider fault recovery and its impact. In this paper, we investigate the problem of workflow scheduling in clouds, considering the probability that cloud resources may fail during execution. We formulate this problem as a multi-objective optimization model. The first optimization objective is to minimize the overall completion time and the second one is to minimize the overall execution cost. Based on the proposed optimization model, we develop a heuristic-based algorithm called Min-min based time and cost tradeoff (MTCT). We perform extensive simulations with four different real world scientific workflows to verify the validity of the proposed model and evaluate the performance of our algorithm. The results show that, as expected, fault recovery has significant impact on the two performance criteria, and the proposed MTCT algorithm is useful for real life workflow scheduling when both of the two optimization objectives are considered
A multi-phenotype genome-wide association study of clades causing tuberculosis in a Ghanaian- and South African cohort
(ELSEVIER, 2021) Müller J. Stephanie; Schurz Haiko; Owusu-Dabo Ellis; Tromp Gerard; Hoal G. Eileen....et al
Despite decades of research and advancements in diagnostics and treatment, tuberculosis remains a major public health concern. New computational methods are needed to interrogate the intersection of host- and bacterial genomes. Paired host genotype datum and infecting bacterial isolate information were analysed for associations using a multinomial logistic regression framework implemented in SNPTest. A cohort of 853 admixed South African participants and a Ghanaian cohort of 1359 participants were included. Two directly genotyped variants, namely rs529920 and rs41472447, were identified in the Ghanaian cohort as being statistically significantly associated with risk for infection with strains of different members of the MTBC. Thus, a multinomial logistic regression using paired host-pathogen data may prove valuable for investigating the complex relationships driving infectious disease.
A multidimensional study of public satisfaction with the healthcare system: a mixed-method inquiry in Ghan
(BMC, 2021) Amoah, Padmore Adusei; Nyamekye, Kingsley Atta; Owusu‑Addo, Ebenezer; 0000-0002-1614-2965
Background: Many governments in sub-Saharan Africa have recently sought to improve their health systems by increasing investment in healthcare facilities and introducing social insurance programmes. However, little is known about the impact of these intended improvements on public perceptions about the healthcare systems. This article examines whether and why people of diferent socioeconomic and ideological backgrounds are satisfed (or not) with the current healthcare system in Ghana from a social ecological perspective. Method: Data were elicited from a cross-sectional mixed-method study conducted in four regions in Ghana in 2018. We used ordinal logistic regression and thematic analysis techniques to analyse the data. Results: Satisfaction with the healthcare system was generally low. From our quantitative study, intrapersonal factors (e.g., being older and having good health and well-being status); interpersonal factors (e.g., linking social capital); community factors (e.g., living in rural areas); and organisational and public policy factors (e.g., trust in the health system, favouring welfare policies, and being interested in politics) were positively associated with satisfaction with the healthcare system. These were corroborated by the qualitative study, which showed that poor attitudes of health personnel, fnancial constraints, perceived poor health facilities, and perceived inefcacy of services contribute to dis‑ satisfaction with the healthcare system. Conclusion: Strategies to improve satisfaction with the healthcare system in Ghana should incorporate ecological perspectives by considering factors such as demographic profle, health needs, political orientation, issues of trust in the healthcare system, and the dynamics and impact of social relationships of populations concerned.
A Mystery and Reality Divine Revelations at Jerusalem No. 2 at Nkoranza in the Catholic Diocese of Techiman
(St. Francis Press Ltd, 2019) Addai, Andrews; Kuusaana, Maria Marciana
A New Generated Family of Distributions: Statistical Properties and Applications with Real-Life Data
(Wiley / Hindawi, 2023) Okutu, John Kwadey; Frempong, Nana Kena; Appiah, Simon K.; Adebanji, Atinuke O.; 0000-0002-7138-3526
Several standard distributions can be used to model lifetime data. Nevertheless, a number of these datasets from diverse fields such as engineering, finance, the environment, biological sciences, and others may not fit the standard distributions. As a result, there is a need to develop new distributions that incorporate a high degree of skewness and kurtosis while improving the degree of goodness-of-fit in empirical distributions. In this study, by applying the T-X method, we proposed a new flexible generated family, the Ramos-Louzada Generator (RL-G) with some relevant statistical properties such as quantile function, raw moments, incomplete moments, measures of inequality, entropy, mean and median deviations, and the reliability parameter. The RL-G family has the ability to model “right,” “left,” and “symmetric” data as well as different shapes of the hazard function. The maximum likelihood estimation (MLE) method has been used to estimate the parameters of the RL-G. The asymptotic performance of the MLE is assessed by simulation analysis. Finally, the flexibility of the RL-G family is demonstrated through the application of three real complete datasets from rainfall, breaking stress of carbon fibers, and survival times of hypertension patients, and it is evident that the RL-Weibull, which is a special case of the RL-G family, outperformed its submodels and other distributions
A NovelComputerVisionModel forMedicinal Plant Identification Using Log-Gabor Filters and Deep Learning Algorithms
(Computational Intelligence and Neuroscience, 2022) Oppong, Stephen Opku; Twum, Frimpong; Acquah-Hayfron, James Benjamin; Missah, Yaw Marfo
Computer vision is the science that enables computers and machines to see and perceive image content on a semantic level. It combines concepts, techniques, and ideas from various fields such as digital image processing, pattern matching, artificial intelligence, and computer graphics. A computer vision system is designed to model the human visual system on a functional basis as closely as possible. Deep learning and Convolutional Neural Networks (CNNs) in particular which are biologically inspired have significantly contributed to computer vision studies. is research develops a computer vision system that uses CNNs and handcrafted filters from Log-Gabor filters to identify medicinal plants based on their leaf textural features in an ensemble manner. e system was tested on a dataset developed from the Centre of Plant Medicine Research, Ghana (MyDataset) consisting of forty-nine (49) plant species. Using the concept of transfer learning, ten pretrained networks including Alexnet, GoogLeNet, Den-seNet201, Inceptionv3, Mobilenetv2, Restnet18, Resnet50, Resnet101, vgg16, and vgg19 were used as feature extractors. The DenseNet201 architecture resulted with the best outcome of 87% accuracy and GoogLeNet with 79% preforming the worse averaged across six supervised learning algorithms. e proposed model (OTAMNet), created by fusing a Log-Gabor layer into the transition layers of the DenseNet201 architecture achieved 98% accuracy when tested on MyDataset. OTAMNet was tested on other benchmark datasets; Flavia, Swedish Leaf, MD2020, and the Folio dataset. The Flavia dataset achieved 99%, Swedish Leaf 100%, MD2020 99%, and the Folio dataset 97%. A false-positive rate of less than 0.1% was achieved in all cases.
A probabilistic assessment of the contribution of wastewater-irrigated lettuce to Escherichia coli O157:H7 infection risk and disease burden in Kumasi, Ghana
(IWA Publishing 2015, 2015) R. C. Abaidoo; 0000-0002-1235-2252
Wastewater use for vegetable production is widespread across the cities of many developing countries. Studies on the microbial health risks associated with the practice have largely depended on faecal indicator organisms with potential underestimation or overestimation of the microbial health risks and disease burdens. This study assessed the Escherichia coli O157:H7 infection risk and diarrhoeal disease burden measured in disability-adjusted life years (DALYs) associated with the consumption of wastewater-irrigated lettuce in Kumasi, Ghana using data on E. coli O157:H7 in ready-to-harvest, wastewater-irrigated lettuce. Two exposure scenarios – best case and worst case – associated with a single consumption of wastewater-irrigated lettuce were assessed. The assessment revealed wastewater-irrigated lettuce is contributing to the transmission of E. coli O157: H7 in Kumasi, Ghana. The mean E. coli O157:H7 infection risk and DALYs in the wet and dry seasons, irrespective of the exposure scenario, were above the World Health Organization tolerable daily infection risk of 2.7 × 10 7 per person per day and 10 6 DALYs per person per year. It is recommended that legislation with clear monitoring indicators and penalties is implemented to ensure that farmers and food sellers fully implement risk mitigating measures

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