KNUSTSpace

Institutional Repository of the Kwame Nkrumah University of Science and Technology

On this portal we showcase the intellectual output of the university..

 

Communities in DSpace

Select a community to browse its collections.

Now showing 1 - 5 of 6

Recent Submissions

No Thumbnail Available
Item
Estimating malaria transmission risk through surveillance of human–vector interactions in northern Ghana
(Parasites & Vectors, 2023) Yihdego, Yemane; Coleman, Sylvester; Gyamfi, Frank; Kolyada, Lena; Tongren, Jon Eric; Zigrumgabe, Sixte; Dery, Dominc B.; Badu, Kingsley; Obiri-Danso, Kwasi; Boakye, Daniel; , Szumlas, Daniel; Armstead, Jennifer S.; Dadzie, Daniel K.; 0000-0002-0964-0894; 0000-0002-7886-5528
Background Vector bionomics are important aspects of vector-borne disease control programs. Mosquito-biting risks are afected by environmental, mosquito behavior and human factors, which are important for assessing exposure risk and intervention impacts. This study estimated malaria transmission risk based on vector–human interactions in north‑ ern Ghana, where indoor residual spraying (IRS) and insecticide-treated nets (ITNs) have been deployed. Methods Indoor and outdoor human biting rates (HBRs) were measured using monthly human landing catches (HLCs) from June 2017 to April 2019. Mosquitoes collected were identifed to species level, and Anopheles gambiae sensu lato (An. gambiae s.l.) samples were examined for parity and infectivity. The HBRs were adjusted using mosquito parity and human behavioral observations. Results Anopheles gambiae was the main vector species in the IRS (81%) and control (83%) communities. Indoor and outdoor HBRs were similar in both the IRS intervention (10.6 vs. 11.3 bites per person per night [b/p/n]; z = −0.33, P=0.745) and control communities (18.8 vs. 16.4 b/p/n; z = 1.57, P=0.115). The mean proportion of parous An. gambiae s.l. was lower in IRS communities (44.6%) than in control communities (71.7%). After adjusting for human behavior observations and parity, the combined efect of IRS and ITN utilization (IRS: 37.8%; control: 57.3%) on reducing malaria transmission risk was 58% in IRS + ITN communities and 27% in control communities with ITNs alone (z = −4.07, P<0.001). However, this also revealed that about 41% and 31% of outdoor adjusted bites in IRS and control communities respectively, occurred before bed time (10:00 pm). The mean directly measured annual entomologic inoculation rates (EIRs) during the study were 6.1 infective bites per person per year (ib/p/yr) for IRS communities and 16.3 ib/p/yr for control communities. After considering vector survival and observed human behavior, the estimated EIR for IRS communities was 1.8 ib/p/yr, which represents about a 70% overestimation of risk compared to the directly measured EIR; for control communities, it was 13.6 ib/p/yr (16% overestimation). Conclusion Indoor residual spraying signifcantly impacted entomological indicators of malaria transmission. The results of this study indicate that vector bionomics alone do not provide an accurate assessment of malaria transmission exposure risk. By accounting for human behavior parameters, we found that high coverage of ITNs alone had less impact on malaria transmission indices than combining ITNs with IRS, likely due to observed low net use. Reinforcing effective communication for behavioral change in net use and IRS could further reduce malaria transmission.
No Thumbnail Available
Item
Platelet-rich plasma for treating dry eye disease – A systematic review and meta-analysis
(Contact Lens and Anterior Eye, 2024-02) Akowuah, Prince Kwaku; Obinwanne, Chukwuemeka Junior; Owusu, Ebenezer; Kyeremeh, Sylvester; Bonsu, Kwaku; Karikari, Lucy Akua Afriyie; Akomeah, Felicia Akyaa; Nkansah, Ernest Kyei; Kobiah-Acquah, Emmanuel; 0000-0003-3657-6768; 0000-0001-5589-9357; 0000-0003-1612-4350; 0000-0002-7916-0175; 0009-0000-1033-7596; 0009-0006-7208-3513; 0000-0002-3803-7218; 0000-0002-5955-7992
Purpose Dry eye disease has public health and economic significance. Platelet-rich plasma is rich in anti-inflammatory agents and growth factors, both beneficial for ocular surface repair. This study aimed to conduct a systematic review and meta-analysis to summarize the benefits of platelet-rich plasma for treating dry eye disease and its adverse effects. Methods Prospective comparative studies using platelet-rich plasma as monotherapy for dry eye disease were included for efficacy assessment. Before-after studies were included for adverse events assessment. Data sources included PubMed, Google Scholar, Web of Science, and Scopus. A systematic review and meta-analysis protocol was pre-registered on PROSPERO (CRD42022347982). PRISMA guidelines were followed. The National Health Institute (NIH) quality assessment tool for before-after studies, the Cochrane risk of bias tool (RoB2), and the methodological index for non-randomized studies were used to assess the risk of bias. Heterogeneity was assessed using the I2 statistic. Results 19 studies (10 comparative and 9 before-after) were included in the systematic review and meta-analysis. The occurrence rate of adverse effects was 2.6 % (95 % CI: 0.5 – 4.7). The pooled standardized mean difference (SMD) for dry eye symptoms was 0.81 (95 % CI: 0.25 – 1.37; I2 = 82 %; p < 0.00001; Z = 2.84, p = 0.004); tear quality was 0.44 (95 % CI: 0.06 – 0.81; I2 = 67 %; p = 0.003; Z = 2.26, p = 0.02); tear quantity was 0.45 (95 % CI: 0.03 – 0.88; I2 = 74 %; p = 0.0003; Z = 2.10, p = 0.04); and corneal staining 0.72 (95 % CI: 0.14 – 1.30; I2 = 85 %; p < 0.00001; Z = 2.43, p = 0.02). Conclusion The current study shows that platelet-rich plasma is efficacious in managing dry eye disease, significantly reducing dry eye signs and symptoms. Such significant improvements could translate to improved quality of life.
No Thumbnail Available
Item
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
No Thumbnail Available
Item
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.
No Thumbnail Available
Item
Hydro-ethanol extract of Holarrhena foribunda stem bark exhibits anti-anaphylactic and anti-oedematogenic efects in murine models of acute infammation
(BMC Complementary Medicine and Therapies, 2022-03-19) Antwi, Stephen; Oduro‑Mensah, Daniel; Darko Obiri, David; Osafo, Newman; Opoku Antwi, Aaron; Owusu Ansah, Helena; Ocloo, Augustine; Okine, Laud K. N.‑A.
Background: Holarrhena foribunda (G.Don) T.Durand & Schinz stem bark has anecdotal use in Ghanaian folk medi‑ cine for the management of infammatory conditions. This study was conducted to investigate the in vivo anti-infam‑ matory activity of the bark extract using models of acute infammation in male Sprague Dawley rats, C57BL/6 mice and ICR mice. Methods: A 70% hydro-ethanol extract of the stem bark (HFE) was evaluated at doses of 5–500 mg/kg bw. Local ana‑ phylaxis was modelled by the pinnal cutaneous anaphylactic test. Systemic anaphylaxis or sepsis were modeled by compound 48/80 or lipopolysaccharide, respectively. Clonidine-induced catalepsy was used to investigate the efect on histamine signaling. Anti-oedematogenic efect was assessed by induction with carrageenan. Efects on mediators of biphasic acute infammation were studied using histamine and serotonin (early phase) or prostaglandin E2 (late phase). Results: HFE demonstrated anti-infammatory and/or anti-oedematogenic activity comparable to standard doses of aspirin and diclofenac (inhibitors of cyclooxygenases-1 and -2), chlorpheniramine (histamine H1-receptor antagonist), dexamethasone (glucocorticoid receptor agonist), granisetron (serotonin receptor antagonist) and sodium cromogly‑ cate (inhibitor of mast cell degranulation). All observed HFE bioactivities increased with dose. Conclusions: The data provide evidence that the extract of H. foribunda stem bark has anti-anaphylactic and antioedematogenic efects; by interfering with signalling or metabolism of histamine, serotonin and prostaglandin E2 which mediate the progression of infammation. The anti-infammatory and antihistaminic activities of HFE may be relevant in the context of the management of COVID-19.
No Thumbnail Available
Item
Rainfall Prediction Using Machine Learning Algorithms for the Various Ecological Zones of Ghana
(IEEE Access, 2022-12) Appiah-Badu, Nana Kofi Ahoi; Missah, Yaw Marfo; Amekudzi, Leonard K.; Ussiph, Najim; Frimpong, Twum; Ahene, Emmanuel; 0000-0002-3029-4498; 0000-0002-2926-681X; 0000-0002-2186-3425; 0000-0002-6973-7495; 0000-0002-1869-7542; 0000-0002-0810-1055
Accurate rainfall prediction has become very complicated in recent times due to climate change and variability. The efficiency of classification algorithms in rainfall prediction has flourished. The study contributes to using various classification algorithms for rainfall prediction in the different ecological zones of Ghana. The classification algorithms include Decision Tree (DT), Random Forest (RF), Multilayer Perceptron (MLP), Extreme Gradient Boosting (XGB) and K-Nearest Neighbour (KNN). The dataset, consisting of various climatic attributes, was sourced from the Ghana Meteorological Agency spanning 1980 – 2019. The performance of the classification algorithms was examined based on precision, recall, f1-score, accuracy and execution time with various training and testing data ratios. On all three training and testing ratios: 70:30, 80:20 and 90:10, RF, XGB and MLP performed well, whereas KNN performed least across all zones. In terms of the execution time of the models, Decision Tree is consistently portrayed as the fastest, whereas MLP used the most run time.
No Thumbnail Available
Item
Aurantio-obtusin alleviates allergic responses in ovalbumin-induced rhinitis
(Scientific African, Elsevier, 2023-11-30) Nyarko, Mavis Sersah; Danquah, Cynthia Amaning; Antwi, Aaron Opoku
Allergic rhinitis (AR) is a growing global health concern. Despite being non-fatal, it has a detrimental effect on people’s quality of life and poses a significant economic burden. In this study, we aimed to evaluate the anti-allergic effects of aurantio-obtusin against ovalbumin-induced murine model of allergic rhinitis. Aurantio-obtusin was administered to rats orally after sensitization to ovalbumin. Results of the study suggested that aurantio-obtusin causes a significant reduction in nose rubs and sneeze as compared to the vehicle-treated disease control group. The aurantioobtusin treated group showed a dose-dependent significant reduction in serum TNF-α, IL-4, and IL-6 levels as well as histamine levels in the nasal mucosa. Additionally, it decreased neutrophil and eosinophil numbers in blood of AR rats’. In the nasal tissues of the vehicle-treated rats that were subjected to an OVA challenge, the histology of the nasal mucosa of AR rats revealed aberrant histological changes. A variety of histological abnormalities, including vascular congestion in the nasal mucosa, substantial inflammatory cell infiltration, and obvious alveolar wall oedema were present. In the rats treated with aurantio-obtusin, these characteristics were reversed. Collectively, the findings suggests that aurantio-obtusin could be used to enhance current AR treatment approaches.