20 research outputs found
BIOACCUMULATION OF HEAVY METALS IN AFRICAN RED SNAPPER (Lutjanus agennes) AND CASSAVA FISH (Pseudotolithus senegalensis) CAUGHT OFF THE COAST OF ACCRA, GHANA
The level of Cu, Fe, Mn, Pb, and Zn in African red snapper (Lutjanus agennes) and cassava fish (Pseudotolithus senegalensis) caught off the coast of Accra, Ghana, were monitored from November 2011 to March 2012 using atomic absorption spectrophotometry. Over the five months period, variations occurred in the level of each of the heavy metals in each of the fish species.  The heavy metals accumulated in the gills and bones more than in the muscle tissues of type of fish. The order of accumulation of the heavy metals in African red snapper in terms of magnitude were Zn>Pb>Fe>Mn>Cu in the bones, Fe>Zn>Pb>Mn>Cu in the gills and Fe>Pb>Zn>Mn>Cu in the muscle tissue. For cassava fish the order was Fe>Zn>Pb>Mn>Cu in the bones, Fe>Pb>Zn>Mn>Cu in the muscle, and Fe>Pb>Zn>Mn>Cu in the gills. In the muscle tissue, the part of fish which is normally consumed, the mean value for the various heavy metals over the five months period in the African red snapper were Cu, 0.73 mg/kg; Fe,; 8.18 mg/kg Mn, 0.66 mg/kg; Pb, 7.04 mg/kg; and Zn, 5.16 mg/kg. In cassava fish, the mean values in the muscle tissues were Cu, 0.53 mg/kg; Fe, 9.38; Mn, 0.67 mg/kg; Pb, 5.90 mg/kg; Zn, 6.18 mg/kg. The concentrations of the heavy metals found in both fish species were mostly above the safe limits recommended by WHO. Key words: Fish, Heavy metals, accumulation, bioaccumulation, red snapper, cassava fis
Environmentally friendly agent against fall armyworm (Spodoptera frugiperda): Antifeedant potency of mentha spicata aqueous extracts
The rising trends of insect resistance, coupled with escalating environmental pollution from synthetic pesticides, heighten the need for a more effective and, non-hazardous agents to control insect/pests. Different aqueous extracts of Mentha spicata were screened for their phytochemical constituents and their antifeedant activities against Spodoptera frugiperda. Screening of the different aqueous extracts of Mentha spicata obtained by cold maceration revealed the presence of phenolics and tannins. The concentration of phenols and tannins in the water, glycerine, and glycerine plus water (glycerine-water) extracts were significantly different (p \u3c 0.05). Mentha spicata water extract had a greater antifeedant activity against Spodoptera frugiperda as compared to glycerine and glycerine-water (60 : 40, v/v) extracts at a concentration of 5g/100 mL. The estimated % antifeedant activity recorded were 97 as against 8.21 and 49.81, respectively. Aqueous neem seed water extracts gave an estimated % antifeedant activity of 93.07 and it served as a control. Saponins were absent in all extracts and only water extracts had alkaloids present. The simple, non-hazardous, and cost-saving extraction method demonstrated could be applied in both commercial and subsistent farming to counteract the damnable effects of Spodoptera frugiperda infestation
Teacher-Trainees’ Perception of Guidance Services in Colleges of Education in the Volta Region, Ghana
Students need guidance and counselling at various levels of their educational development. The general purpose of this study was to find out teacher-trainees’ perception of guidance services offered in Colleges of Education in the Volta Region of Ghana. The research study was guided by Existential theory and Humanistic person-centred theory. The study is a quantitative research which employed descriptive survey design. A sample size of 346 respondents made up of teacher-trainees was selected from seven Colleges of Education in the Volta Region using a multi-stage sampling procedure with purposive, quota, convenience and simple random sampling techniques. Data was collected with a 55-item researcher-made questionnaire with reliability coefficient of 0.89 alpha and content validity was established for the items. One-Way Analysis of Variance (ANOVA) and Independent samples t-test were used to analyze the four research hypothesis stated for the study. The statistical packages for social sciences (SPSS) software application were used to test hypothesis at 0.05 significant level. The study reveals that guidance and counselling needs of teacher-trainees is the same for male and female. It was recommended that Ghana Education Service should ensure that trained and qualified counsellors are posted to the colleges to offer services that will meet the needs of teacher-trainees. Keywords: Teacher-trainees, Perceptions, Guidance services, Colleges of Education. DOI: 10.7176/RHSS/9-24-06 Publication date: December 31st 201
Characterisation of sandalwood essential oils using high performance thin-layer chromatography and high resolution gas chromatography mass spectrometry
Sandalwood essential oil is extensively used in perfumes, cosmetics, and pharmaceuticals. The unique woody aroma of sandalwood essential oil is produced by (Z)-α-santalol and (Z)-β-santalol and these two compounds influence the oil quality. Variation in sesquiterpene composition and oil yield have been observed both within and across Santalum species. Gas Chromatography-Mass Spectrometry (GC-MS) is a technique commonly used to identify and quantify sesquiterpene compounds in sandalwood essential oils. High Performance Thin-Layer Chromatography (HPTLC) has yet to be fully explored as an alternative to GC-MS in authenticating sandalwood essential oils of different species. In this study, sandalwood essential oils were characterised using HPTLC and high resolution GC-MS.
The potential of HPTLC to identify differences in sandalwood essential oils of Santalum album, Santalum spicatum, Santalum austrocaledonicum, Santalum paniculatum, Santalum lanceolatum and a natural substitute for sandalwood, Osyris lanceolata, was explored. Variation was observed in the profile of bands and peak intensity profiles of the essential oils with some bands being unique to the individual species. The potential of HPTLC fingerprinting as a quality control tool in identifying differences in sandalwood essential oils was demonstrated (Study I).
Study I was limited to a maximum of five oils for each species studied. The natural variability was likely not captured for such a small sample size. The potential of HPTLC to generate a sandalwood profile that better represents Santalum album, Santalum spicatum, Santalum austrocaledonicum and Santalum paniculatum was explored. Santalum spicatum could confidently be distinguished from other species with a distinctive pink band at RF 0.71 and unique peak intensities at RF 0.28, 0.45 and 0.47. Santalum album and Santalum paniculatum could easily be distinguished from each other with distinctive peak intensities at RF 0.51 and 0.17 respectively. The intense peak at RF 0.09 displayed by Santalum austrocaledonicum distinguished it from Santalum album, and Santalum paniculatum but not Santalum spicatum (Study II).
An ultrasonication extraction method was optimised for extraction of essential oil from Western Australia sandalwood (Santalum spicatum) using n-hexane, isopropanol, and n-hexane/isopropanol (50:50, v/v) for different extraction times. Oil yield was moderately influenced by solvent, particle size and extraction time. Extracting for 30 minutes with particle size 250µm-500µm using n-hexane gave the highest oil yield and santalol content. The santalol content achieved in Santalum spicatum extract was influenced by particle size and solvent (Study III).
The optimised method in Study III was moderately modified and successively applied to extract oil from 340 milled heartwoods of Santalum spicatum. GC-MS analysis was performed on oil extracts. Variation in sesquiterpene composition of 340 heartwood oil extracts of Santalum spicatum sampled from 19 locations across five regions in Western Australia was explored. Variation was observed in sesquiterpene composition, and oil yield both across and within all five regions. Heartwood oil extracts from trees in the north obtained higher oil yield and santalol content when compared to oil extracts from trees in the south. Interestingly, one oil extract of S. spicatum met the ISO specification of 90% combined α-santalol and β-santalol in Santalum album, obtaining 67.47% α-santalol and 22.92% β-santalol (Study IV)
The cocoa industry in Ghana and the Ivory Coast, a comparative study of government agricultural policies and their impact
Strathclyde theses - ask staff. Thesis no.: T6271The cocoa industry has been the economic pillar of Ghana and the Ivory Coast for over three-quarters of a century. Both countries have depended on the industry for the bulk of the wherewithal required for economic development. In Ghana, the industry has however, since the beginning of the 1970s, shown clear signs of decline in terms of output. Cocoa output in Ghana has slumped from 538,000 tonnes in 1965 to 175,000 tonnes in 1985. In the Ivory Coast, cocoa output has on the contrary, risen from 148,000 tonnes in 1965 to 565,000 tonnes in 1985. Ghana is currently trailing behind Ivory Coast and Brazil in cocoa beans production. The objective of the study has been to identify the causes of the decline and growth-of the cocoa industry in Ghana and the Ivory Coast respectively through an in-depth study of government agricultural policies. The rationale behind the comparative study is to bring out the strengths and weaknesses in the agricultural policies of the two countries so that Ghana can sift out the good policies that have aided the Ivory Coast cocoa industry to flourish and use them to revamp, its floundering cocoa industry. The study employs multiple regression, cost-benefit and domestic resource costs techniques to analyse government agricultural policies and to assess the relative profitability of cocoa production. The study has revealed that the major explanatory factor for the current state of the industry in both countries is the producer price policy of the governments of the two countries. While producer prices are not favourable in Ghana, they tend tobe relatively high in the Ivory Coast. The poor producer price policy of the government of Ghana has led to a shift of resources from the cocoa industry to other more lucrative ventures such as food-cropping and commerce. Other factors that have been discovered through the study to account for the decline of cocoa output in Ghana include inefficient marketing system, lack of farm inputs and poor implementation of cocoa rehabilitation projects. The results of the comparative advantage analysis suggest that there is the need for Ghana to embark on a policy of agricultural diversification. Besides cocoa, a cash crop whose development is worth encouraging by the government of Ghana is the oil palm. Based on the experience of the Ivory Coast, a number of recommendations have been suggested in the concluding chapter for adoption by the government of Ghana. These policy recommendations include a yearly upward adjustment of the cocoa producer price to a level that will leave the cocoa farmer with an appreciable profit margin, the privatization of the cocoa marketing board, a regular and an adequate supply of farm inputs and an efficient implementation of cocoa rehabilitation projects.The cocoa industry has been the economic pillar of Ghana and the Ivory Coast for over three-quarters of a century. Both countries have depended on the industry for the bulk of the wherewithal required for economic development. In Ghana, the industry has however, since the beginning of the 1970s, shown clear signs of decline in terms of output. Cocoa output in Ghana has slumped from 538,000 tonnes in 1965 to 175,000 tonnes in 1985. In the Ivory Coast, cocoa output has on the contrary, risen from 148,000 tonnes in 1965 to 565,000 tonnes in 1985. Ghana is currently trailing behind Ivory Coast and Brazil in cocoa beans production. The objective of the study has been to identify the causes of the decline and growth-of the cocoa industry in Ghana and the Ivory Coast respectively through an in-depth study of government agricultural policies. The rationale behind the comparative study is to bring out the strengths and weaknesses in the agricultural policies of the two countries so that Ghana can sift out the good policies that have aided the Ivory Coast cocoa industry to flourish and use them to revamp, its floundering cocoa industry. The study employs multiple regression, cost-benefit and domestic resource costs techniques to analyse government agricultural policies and to assess the relative profitability of cocoa production. The study has revealed that the major explanatory factor for the current state of the industry in both countries is the producer price policy of the governments of the two countries. While producer prices are not favourable in Ghana, they tend tobe relatively high in the Ivory Coast. The poor producer price policy of the government of Ghana has led to a shift of resources from the cocoa industry to other more lucrative ventures such as food-cropping and commerce. Other factors that have been discovered through the study to account for the decline of cocoa output in Ghana include inefficient marketing system, lack of farm inputs and poor implementation of cocoa rehabilitation projects. The results of the comparative advantage analysis suggest that there is the need for Ghana to embark on a policy of agricultural diversification. Besides cocoa, a cash crop whose development is worth encouraging by the government of Ghana is the oil palm. Based on the experience of the Ivory Coast, a number of recommendations have been suggested in the concluding chapter for adoption by the government of Ghana. These policy recommendations include a yearly upward adjustment of the cocoa producer price to a level that will leave the cocoa farmer with an appreciable profit margin, the privatization of the cocoa marketing board, a regular and an adequate supply of farm inputs and an efficient implementation of cocoa rehabilitation projects
Preharvest and Postharvest Factors Affecting the Quality and Shelf Life of Harvested Tomatoes: A Mini Review
Tomato production can serve as a source of income for most rural and periurban producers in most developing countries of the world. However, postharvest losses make its production unprofitable in these parts of the world. Postharvest losses in tomatoes can be as high as 42% globally. Postharvest losses in tomatoes can be either quantitative or qualitative. Even though emphasis in crop research nowadays is increasing shifting from quantity to quality of produce, there is still little improvement in the quality of commercially produced tomato varieties, hence resulting in high quality losses. From the study it was discovered that the postharvest quality status of tomatoes partly depended on some preharvest practices carried out during production. Some of these factors are fertiliser application, pruning, maturity stage, cultivar selection, and irrigation. Using best postharvest handling practices or factors such as temperature, relative humidity, gases in storage, postharvest calcium chloride application, and physical handling procedures to maintain the quality after harvest was also critical. It was concluded by this study that understanding and managing both preharvest and postharvest factors properly will reduce the postharvest quality losses in tomatoes