ghanaopendata/ghanaian-research-english huggingface dataset:
Polyamide Nanofiber Membranes Functionalized with Zinc Phthalocyanines

Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2 diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol 21 Zn min 21. During short term leaching tests, phthalocyanines could not be detected

Source: UCC
Polychlorinated biphenyls (PCBs) in Africa: a review of environmental levels

Several studies have shown an increase in PCB sources in Africa due to leakage and wrongly disposed transformers, continuing import of e-waste from countries of the North, shipwreck, and biomass burning. Techniques used in the recycling of waste such as melting and open burning to recover precious metals make PCBs contained in waste and other semi volatile organic substances prone to volatilization, which has resulted in an increase of PCB levels in air, blood, breast milk, and fish in several regions of Africa. Consequences for workers performing these activities without adequate measures of protection could result in adverse human health effects. Recent biodegradation studies in Africa have revealed the existence of exotic bacterial strains exhibiting unique and unusual PCB metabolic capability in terms of array of congeners that can serve as carbon source and diversity of congeners attacked, marking considerable progress in the development of effective bioremediation strategies for PCB-contaminated matrices such as sediments and soils in tropical regions. Action must be taken to find and deal with the major African sources of these pollutants. The precise sources of the PCB plume should be pinned down and used to complete the pollutant inventories of African countries. These nations must then be helped to safely dispose of the potentially dangerous chemicals

Source: UCC
Polychlorinated biphenyls in coastal tropical ecosystems: Distribution, fate and risk assessment

Polychlorinated biphenyls (PCBs) though banned still find use in most developing countries including Ghana. PCB congener residues in sediments in the coastal regions of Ghana were determined. Sediment samples (n¼80) were collected between June 2008 and March 2009, extracted by the continuous soxhlet extraction using (1:1) hexane-acetone mixture for 24 h and analyzed with a CP 3800 gas chromatogram equipped with 65Ni electron capture detector (GC–ECD) and a mixed PCBs standard of the ICES 7 as marker, after clean-up. Validation of the efficiency and precision of the extraction and analytical methods were done by extracting samples spiked with 2 ppm ICES PCB standard and a certified reference material 1941b for marine sediments from NIST, USA, and analyzed alongside the samples. Total PCBs detected in sediments during the dry and wet seasons were, respectively, 127 and 112 mg/kg dry weight (dw), with a mean concentration of 120 mg/kg (dw). The composition of PCB homologues in the sediments were dominated by tri-, penta- and tetra-PCBs. There was no correlation between organic carbon (OC) of the sediments and total PCBs content. Risk assessments conducted on the levels indicated that PCB levels in sediments along the coastal region of Ghana poses no significant health risk to humans

Source: UCC
Polycyclic aromatic hydrocarbon(PAH) contamination in smoke-cured fish products

In this study, 108 fish samples of smoke cured fish Sardinella aurita (sardines/herrings)collected from 12 major fishing communities along the coastal belt of Ghana were extracted with Soxhlet apparatus using dichloromethane (DCM),and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs)using the GC/MS (Varian 3800 GC system with 8400 auto-sampler) to determine levels, distribution and the characterization of their sources. The mean total PAHs in the smoked sardines from the various communities ranged from 510.59 mg/kg to 1461.79 mg/kg for all seasons with a mean value of 716.84 mg/kg.The benzo[a]pyrene (BaP)had a maximum mean levelof73.78 mg/kg. The unit risk of carcinogenic PAHs for benzo[a]pyrene,chrysene,dibenz[a,h]anthracene,benzo[a]anthracene,benzo[k]- fuoranthene, benzo[b] fuoranthene, and indenol[1,2,3-cd] pyrene associated with oral ingestion of smoked sardine was calculated to be 6.1 0 7 f for adults and 1.6 0 7 for children. There is a significant correlation between the fish lipid content and the total PAH levels. The average lipid content of the smoked sardine samples collected varied among the various fishing seasons (3 seasons)in Ghana. A significantly high accumulation of PAHs was found in the smoke-cured fish as compared to the non-smoke-cured fish control samples, which showed PAH levels that were below detection (0.10–2.0 mg/kg). This study highlights the increased danger of consuming smoke-cured fish in Ghana as some of the PAHs are known to be carcinogenic. These results indicate that there is a need to find alternative ways of curing fish other than the traditional smoking process

Source: UCC
Polymodal Therapy for High Grade Gliomas: A Case Report of Favourable Outcomes following Intraoperative Radiation Therapy

High grade gliomas, frequently with their infiltrative nature, often make the outcome from neurosurgical intervention alone unsatisfactory. It is recognized that adjuvant radiochemotherapy approaches offer an improved prognosis. For these reasons, we opted for surgical debulking, intraoperative radiation therapy (IORT) in combination with whole brain irradiation therapy and chemotherapy (temozolamide cycles) in the management of a 42year-old lady with Glioblastoma Multiforme (GBM). Her troublesome symptoms improved after 3 months of this polymodal therapy and remained independently functional for more than two years.

Source: UCC
Polymorphism of the tropical butterfly, Danaus chrysippus L., in Africa

The polymorphism of Danaus chrysippus is anomalous since it is a distasteful butterfly. In a field study of the B locus polymorphism in Ghana, significant changes in the morph frequencies were recorded over eighteen months at Cape Coast. There were also significant differences between localities. There was some evidence that brown morphs are favoured by wet conditions, and that orange forms have higher survival rates as caterpillars. There were no differences between forms in larval foodplants, sex ratio, body size, wing damage, mating success, or in the effects of weather on adult activity. There was however, strong assortative mating between forms. Crosses with Kenyan females gave aberrant segregations for the sex chromosomes and the C locus. The results are discussed with regard to the hypothesis that polymorphism arose as a result of the overlapping of previously isolated geographical races.

Source: UCC
Polymorphismof the tropical butterfly,danaus chrysippus l., in Africa

The polymorphism of Danaus chrysippus is anomalous since it is a distasteful butterfly. In a field study of the B locus polymorphism in Ghana, significant changes in the morph frequencies were recorded over eighteen months at Cape Coast. There were also significant differences between localities. There was some evidence that brown morphs are favoured by wet conditions, and that orange forms have higher survival rates as caterpillars. There were no differences between forms in larval foodplants, sex ratio, body size, wing damage, mating success, or in the effects of weather on adult activity. There was however, strong assortative mating between forms. Crosses with Kenyan females gave aberrant segregations for the sex chromosomes and the C locus. The results are discussed with regard to the hypothesis that polymorphism arose as a result of the overlapping of previously isolated geographical races. © 1984 The Genetical Society of Great Britain.

Source: UCC
Polyphonie dans le discours des guides touristiques

La polyphonie est un phénomène discursif qui peut définir le discours de tout locuteur. Elle se manifeste à travers, entre autres, le discours rapporté, l’ironie, la négation et la reformulation. Cet article porte sur la polyphonie telle qu’elle se présente grâce au discours rapporté dans le discours oral des guides touristiques. L’étude s’appuie sur un corpus oral en français recueilli auprès des guides touristiques au Togo. L’analyse montre que les guides se servent de la polyphonie pour assurer l’objectivité de leur discours et qu’il y existe la polyphonie simple et la polyphonie complexe

Source: UCC
polytechnic academic and administrators’ perception about the usefulness of the npt (045) leadership and management capacity building project

The study investigated polytechnic academic and administrators’ perceptions about the usefulness of the implementation of the leadership and management capacity building project in Ghanaian polytechnics. The study targeted four public polytechnics in the northern sector which included Sunyani Polytechnic, Wa Polytechnic, Balgatanga Polytecnic and Tamale Polytechnic. Descriptive survey design was adopted for the study. The sample for the study included purposively selected 16 middle-level polytechnic administrators and 25 academic staff who participated in Sub-Project 2 and Sub-Project 3 of the NPT(045) leadership and management capacity building training. The main instruments for data collection were questionnaire and structured interview guide. The Institutional Change Coordinators were interviewed whilst the rest of the participants in the study responded to a four scaled Likert type scaled questionnaire. The instruments were pre-tested at Kumasi Polytechnics to ascertain its validity and reliability. The pre-test result yielded a standardised Chronbach’s alpha of .70. The results revealed that majority of the respondents agreed that the training has improved their performance on the job. It further emerged from the study that there was no statistical difference between academic and administrators about their perceived usefulness of the NPT (045) training. Based on the finding of the study, it is recommended that future leadership and management capacity building training should be decentralized to enable more polytechnic staff to benefit.

Source: UCC
POOR PROGNOSTIC FACTORS OF INTUSSUSCEPTION IN CHILDHOOD AS SEEN IN ILORIN, NIGERIA

This was a prospect~ve study of24 children with intussusception seen over a 3year period of the university of Ilorin Teaching Hospital. Males were more affected than females at a ratio of 3: l, with 70% of the cases occurring in children between 6months and 2years of age. The common presenting symptoms were vomiting in 83.3%, bloody stool in 75%, abdominal distension in 58.3%, diarrhoea in 58.6% and constipation in 37.5% of the cases. An abdominal mass was palpable in 58.3%. Majority of the patients presented late with 70.8% presenting beyond 24 hours from the onset of the symptoms. Ileocolic intussusception accounted for 72.9% of the cases whilst ileo-ileal occurred in 12.5%. Mesenteric lymphadenopathy was the pre-dorminant detectable predisposing factor at surgery in 25% of the cases. Fifty percent had gangrenous bowel requiring resection at surgery. The mortality rate was 29.2%. Mortality was high in those with delayed presentation beyond 48 hours from onset of symptoms (38.5%, odds ratio "OR" = 2.8/, relative risk "RR" = 1.33), severe acidosis (75%, OR=12.0, RR=3.2), temperature> 38.5° centigrade at admission (80%, OR=21.33, RR=4.2), severe dehydration, andrespiratory distress (62.5% and 66.6%, respectively RR=2.3), and a delay in surgical intervention beyond 48hours from admission (66.6%, OR =6.4, RR=2.29). I The poor prognostic factors observed in this study included delayed presentation beyond 48 hours from the onset of symptoms, severe respiratory distress at presentation, temperature> 38.5° centigrade at admission, severe, acidosis, severe dehydration and delay in surgical intervention beyond 48 hours. Children with intussusception still present lale to our facility with the resultant development of the above stated bad prognostic factors and its attendant high mortality.

Source: UCC
Population dynamics and reproductive studies of three commercially important sparid species from Ghanaian waters

This study investigated the catch trends, spatial distributions, exploitation status, and reproductive potential of the sparids – Pagrus caeruleostictus, Dentex canariensis and Dentex gibbosus, in the coastal waters of Ghana. Samples of the species were obtained from commercial catches at Tema, Elmina and Sekondi from February 2016 to July 2017. Also used were secondary data from the Fisheries Scientific Survey Department and Fridtjof Nansen cruise reports. P. caeruleostictus was the most abundant of the three species, while D. gibbosus was the least abundant. The asymptotic length (TL∞) and growth coefficient (K) values for P. caeruleostictus, D. canariensis and D. gibbosus, respectively were 52.7 cm and 0.52 yr-1, 70.9 cm and 0.25 yr-1, and 60.7 cm and 0.16 yr-1. The fishing mortality (F) calculated for the three species was greater than natural mortality (M), accounting for a greater percentage of total mortality (Z), and leading to an exploitation ratio (E) higher than 0.5. Except for D. gibbosus which appeared underexploited (Ecur<Emsy), the other species were exploited above their maximum sustainable yield (Ecur>Emsy). The respective male and female length-at-first sexual maturity was estimated as 36.2 cm and 28.0 cm for P. caeruleostictus, 51.7 cm and 31.6 cm for D. canariensis, and 54.3 cm and 56.4 cm for D. gibbosus. P. caeruleostictus and D. gibbosus had two spawning periods in a year, occurring in September and March, and in January-February and July-October, respectively. D. canariensis, however, had one extended spawning period taking place between May and September. The oocyte diameter frequency distributions were unimodal and the fecundities ranged from about 250,000 to 6,000,000 for all three species.

Source: UCC
Population Dynamics of Chloroscombrus Chrysurus and Decapterus Punctatus in Coastal Waters of Ghana

Carangids are considered as commercially important fish species in Ghana. In recent times, there has been a decline in Ghana’s pelagic stock which includes carangids. The purpose of the study was to assess the population dynamics of some common commercially important carangid stocks in the coast of Ghana to inform management decisions. The study was conducted specifically in the Tema fishing Harbour, the Elmina landing site and the Albert Bosomtwe Sam fishing Harbour in Ghana from November, 2020 to June, 2021. Length- frequency data of fish samples were used to calculate the growth and mortality parameters as well as the exploitation ratio. The growth parameters assessed for Chloroscombrus chrysurus and Decapterus punctatus were; asymptotic length (L∞) = 28.9 and 21.4 cm standard length, growth rate (K) = 0.38 and 0.55 per year, growth performance index (ɸ) =2.50 and 2.40, theoretical age at birth (to) = - 0.23 and -0.08 respectively. The Z/K ratio were 7.26 and 4.51 respectively, indicating that the stock is mortality dominated. Total mortality (Z) was estimated at 2.76 and 2.48 per year, while natural mortality (M) was 0.67 and 1.03 per year and fishing mortality (F) at 2.09 and 1.45 per year respectively. The estimated fishing mortality (F) was found to be greater than the natural mortality. Further, the current exploitation rate (E) was calculated as 0.75 and 0.58, portraying over exploited stock. The length at first maturity (Lm50), was estimated at 13.9 cm and 14.1 cm for male and female Chloroscombrus chrysurus and 14.7 cm and 12.6 cm for male and female Decapterus punctatus. The length at first capture (Lc50) was obtained at 10.6 cm and 10.5 cm respectively. The estimated length at first capture was lower than the length at maturity inferring that these species do not get the chance to spawn at least once before they are harvested. From the study, it was confirmed that the Carangid stock within Ghana’s coastal waters is currently overexploited and there is a need for a decrease in fishing pressure on carangids to aid in sustainable management of the stocks.

Source: UCC
A portable fibre-probe ultraviolet light emitting diode (LED)-induced fluorescence detection system

A portable fibre-probe fluorescence detection system comprising a continuous-wave high-power ultraviolet light emitting diode (UV LED) emitting at 365 nm as excitation source, a bifurcated fbre probe with a six-around-one fibre configuration to illuminate and read from a large target area (∼3.6 mm2) and an integrated PC-coupled spectrometer has been developed. The construction, calibration and operation of the fluorescence detection system are described. Demonstrative test measurements with the system for possible inspection of different ripening stages on some batches of horticultural and agricultural products (lemon, mandarin, banana leaf and ivy leaf) have been performed and results presented. The system is portable, comparatively low cost, easily operated and relative immune to ambient light, thus being suitable for field measurements

Source: UCC
Positive periodic solutions for second-order neutral differential equations with functional delay

We use Krasnoselskii’s fixed point theorem to prove the existence of positive periodic solutions of the second-order nonlinear neutral differential equation d2dt2x(t) + p(t)ddtx(t) + q(t)x(t) = cddtx(t − τ(t)) + f(t, h(x(t)), g(x(t − τ(t))))

Source: UCC
Positive periodic solutions of functional discrete systems with a parameter

The existence of multiple positive periodic solutions of the system of diference equations with a parameter x(n + 1) = A(n, x(n))x(n) + λf(n, xn), is studied. In particular, we use the eigenvalue problems of completely continuous operators to obtain our results. We apply our results to a well-known model in population dynamics. Estudiamos la existencia de soluciones peri´dicas m´ltiples del siguiente sistema de ecuaciones diferenciales con un par´metro x(n + 1) = A(n, x(n))x(n) + λf(n, xn).En particular, usamos los problemas de valores propios de operadores completamente continuos para obtener nuestros resultados. Aplicamos nuestros resultados a modelos de din´mica poblacional bien conocidos

Source: UCC
Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis

Heliotropium indicum is used traditionally as a remedy for conjunctivitis in Ghana.This study therefore evaluated the antiallergic potential of an aqueous whole plant extract of Heliotropium indicum (HIE) in ovalbumin-induced allergic conjunctivitis and attempted to predict itsmode of action.Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization (100 : 10 𝜇g OVA/Al(OH)3 in phosphate-buffered saline [PBS]) and topical conjunctival challenge (1.5mg OVA in 10 𝜇L PBS) in Dunkin-Hartley guinea pigs were estimated after a week’s daily treatment with 30–300mg kg−1 HIE, 30mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, or 10mLkg−1 PBS. Ovalbumin-specific IgG and IgE and total IgE in serum were estimated using Enzyme-Linked Immunosorbent Assay. Histopathological assessment of the exenterated conjunctivae was also performed.The 30 and 300 mg kg−1 HIE treatment resulted in a significantly (𝑝 ≤ 0.001) low clinical score of allergic conjunctivitis. Ovalbuminspecific IgG and IgE as well as total serum IgE also decreased significantly (𝑝 ≤ 0.01–0.001). The conjunctival tissue in HIE treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration. HIE exhibited antiallergic effect possibly by immunomodulation or immunosuppression.

Source: UCC
Possible Mechanism of Anti-Inflammatory Activity and Safety Profile of Aqueous and Ethanolic Leaf Extracts of Pistia Stratiotes Linn (Araceae)

Pistia stratiotes is used extensively in inflammatory disorders in several countries including Ghana. The aim of the study was to investigate the anti-inflammatory property and possible mechanism of action of aqueous and ethanolic leaf extracts of Pistia stratiotes and to ascertain its safety for use. In separate experiments, acute inflammation was induced in the right hind paws of rats using carrageenan, histamine, serotonin, prostaglandin E, and bradykinin. Paw thickness (an indication of inflammation) were measured plethysmographically. Animals were grouped and treated with diclofenac, chlorpheniramine, and granisetron (reference anti-inflammatory agents), or aqueous and ethanolic extracts of Pistia stratiotes at doses of 30, 100, and 300 mg/kg orally. Control groups received distilled water. Paw thicknesses was measured at 30 or 60 min intervals for 2.5 to 4 h for the various procedures. The extracts at all doses signifi-cantly reduced (P≤ 0.05-0.001) paw thickness in all the models of inflammation except the 300 mg/kg doses in carrageenan and serotonin-induced inflammation. The anti-inflammatory effects of the extracts were comparable to the reference drugs. Acute and delayed toxicity test revealed that the aqueous extract causes hemolysis of red blood cells (reduced count and presence of uro-bilinogen in urine) and possible acute kidney function impairment (proteinuria and microalbu-minuria). The aqueous and ethanolic extracts of P. stratiotes have anti-inflammatory activity in acute inflammation induced with carrageenan, through the inhibition of histamine, serotonin, prostaglandin, and bradykinin. Hematological profile as well as liver and kidneys function should be monitored when used orally for the treatment of inflammatory disorders.

Source: UCC