Tanzania Journal of Science最新文献

{"title":"Experimental Measurements of Ignition Delay Times of Iso-octane/n-Butanol Blend Mixtures in Rapid Compression Machine (RCM)","authors":"Myeji Materego, Derek Bradley","doi":"10.4314/tjs.v49i3.6","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.6","url":null,"abstract":"Among oxygenated alternative fuels, n-butanol is considered as a promising alternative biofuel which can partially (or fully) replace conventional transportation fuels currently in use. However, before n-butanol can be commercially utilised, its fundamental combustion characteristics need to be fully understood. In this work, the effect of adding n-butanol on autoignition property of iso-octane was studied. Measurements of ignition delay times for the two blends of n-butanol proportions of 30% and 50% by mole weight were made in a Rapid Compression Machine for stoichiometric mixtures at 2.0 MPa and temperature range 651-918 K. n-butanol increased ignition delay times of iso-octane at lower temperatures and hence acted as an octane enhancer, while at higher temperatures delay times were reduced. In the intermediate temperatures there was visually no difference in delay times between the two blends. Throughout the temperature range studied, the delay times of both blends were much closer to those of pure n-butanol which suggests that the combustion chemistry of n-butanol was dominant over that of iso-octane. These results have shown that n-butanol can enhance fuel octane rating and therefore can potentially improve thermal efficiency of SI engines, whilst CI engines can benefit from the reduced delay times at higher temperatures.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135082909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Bacillus thuringiensis, Beauveria bassiana, Neem, and a Tomato Intercrop on Diamondback Moth (Plutella xylostella L.) (Lepidoptera: Plutellidae) in Tharaka-Nithi County, Kenya","authors":"Ceciliah N. Ngugi, Jesca N. Mbaka, Hellen W. Muthengi","doi":"10.4314/tjs.v49i3.1","DOIUrl":"https://doi.org/10.4314/tjs.v49i3.1","url":null,"abstract":"Cabbage (Brassica oleracea var. capitata) is an important crop in Kenya, ranked 3rd among the exotic vegetables. Diamondback moth (DBM) is a major cabbage pest that can cause a 100% loss in yield if not well managed. Farmers indiscriminately use synthetic pesticides associated with environmental, health, and pest resistance concerns to manage the DBM. To increase the availability of technologies for effective management of DBM in Kenya, three biopesticides; BioPower (Beauveria bassiana 1.0 x 108 CFUs/g), Dipel DF® (Bacillus thuringiensis subsp. kurstaki), Neemraj Super 3000 (Azadirachtin 0.3% EC), and a tomato intercrop were evaluated. Cabbages (30 plants) spaced at 40 cm x 60 cm were established in 6 m x 6 m plots in 3 replicates per treatment. The treatments applications were; B. bassiana 100 g/20 L, B. thuringiensis 20 g/20 L, and neem 20 mL/20 L. A row of tomato intercrop was established in every two rows of cabbage and distilled water was used on the untreated control. Data on the number of damaged leaves, live larvae, and marketable yields for two seasons was collected from five leaves of ten randomly selected cabbage plants. Results showed significant differences (P ≤ 0.05) between the control and treatments in the mean number of live larvae and the number of damaged leaves. However, there were no significant marketable yield differences between the treatments (P ≥ 0.05). In conclusion, the three bio-pesticides and the tomato intercrop were effective against the DBM damage on cabbage leaves and can be part of integrated pest management (IPM) packages for DBM management on cabbage. There is a need to determine why the treatments did not result in meaningful outcomes against the DBM population and cabbage head weights. In addition, a cost-benefit analysis of each treatment is necessary.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135083033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ameliorative Effects of Vitamins C and E on Haematotoxicity and Spleen Histopathology Induced by Dichlorvos Insecticide in Female Wistar Rats","authors":"Halima Mfaume, Harishchandra Pratap, Claudius Luziga, Felister Urasa","doi":"10.4314/tjs.v49i2.21","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.21","url":null,"abstract":"This research aimed to assess the toxicological effects of dichlorvos insecticide (2,2-dichlorovinyl dimethyl phosphate or DDVP) on haematological indices of female Wistar rats and to investigate the antioxidant properties of vitamins C and E in ameliorating haematotoxicity. The rats were divided into 6 groups; control-water, control-oil, dichlorvos group, dichlorvos + vitamin C group, dichlorvos + vitamin E group and dichlorvos + vitamin C + E group. Dichlorvos and vitamins were orally administered to rats with an interval of half an hour between treatments. The control-oil group was given 2 ml corn oil and the control-water group was given water adlib. The treatments were done for 28 consecutive days and blood samples were taken by cardiac puncture. The following haematological parameters were analysed: RBC, WBC, Hb, PCV, MCV, MCH, MCHC and THR. Bone marrow smears were prepared on 14th and 28th days for various blood stem cells evaluation and spleen tissues for histopathology. There was a significant decrease (p ˂ 0.01) in RBC counts, PCV, MCV and MCH values, whereas the WBC, THR counts and MCHC values increased significantly (p ˂ 0.01) in dichlorvos treated rats as compared to the controls and dichlorvos + vitamins co-treated groups. There were no significant differences in blood parameter counts between controls and dichlorvos + vitamins co-treated groups. In the bone marrow smear of the dichlorvos treated group, there was increased number of megakaryocytes and mature neutrophils. In conclusion, findings from the current study revealed that, vitamins C and E supplements were capable of mitigating the haematotoxic effects induced by dichlorvos insecticide in Wistar rats.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136369974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of the Botanical Extracts, Azadirachta indica (Sapindales: Meliaceae) and Tagetes minuta (Asterales: Asteraceae) in the Control of Cabbage Insect Pests in Iringa District, Tanzania","authors":"Levocatus M. Rwegoshora, Vendeline E. Tairo, Moses I. Olotu","doi":"10.4314/tjs.v49i2.11","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.11","url":null,"abstract":"Although botanical extracts have been widely studied globally, the efficacy of neem and Mexican marigold against cabbage insect pests is scanty. Field experiments were conducted at Kalenga and Mgera in 2022 using a randomized complete block design. Four treatments (neem, Mexican marigold, a mixture of the two extracts and untreated) were replicated three times. In Kalenga, damage levels for treated plots varied significantly from 3.33 to 9.20% and 5.0 to 18.33%, while for untreated plots varied from 37.70 to 45.85% during the rainy and dry seasons, respectively (F(3, 499) = 111.71, p < 0.05). A similar trend was recorded in Mgera, the damage levels varied significantly between treated (4.44–15.83%) and untreated plots (34.40–46.60%) (F(3, 449) = 94.23, p < 0.05). Treated plots had higher marketable cabbage yields (30.6–43.10 t/ha) than untreated plots (4.78–11.20 t/ha), which differed significantly in Kalenga (F (3, 67) = 141.79, p < 0.05) and Mgera (F (3, 67) = 53.36, p < 0.05). These extracts have shown insecticidal properties, can serve as promising candidates for further studies aimed at isolating active compounds for scaling up ecologically friendly strategies of controlling pests and improve the quality of cabbage products.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethnobotanical Survey, Consumption Pattern and Genetic Conservation of Leafy Vegetables in South-West Nigeria","authors":"Temitope O Onuminya, Michael I Osundinakin, Oluwatoyin T Ogundipe","doi":"10.4314/tjs.v49i2.18","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.18","url":null,"abstract":"Leafy vegetables are important in human nutrition; however, their diversity as seen in the dishes in South western Nigeria appears to be diminishing. Many popular delicacies are no longer available in the markets. Therefore, this research was conducted to identify and document leafy vegetables in South West Nigeria, assess their ethnobotanical uses from questionnaires administered to farmers/sellers, secure their genetic resource base, and improve their value chain in South-West Nigeria. Vegetable samples were collected from different local communities in five South-West states in Nigeria, identified using manual/flora, and authenticated at the University of Lagos Herbarium. One thousand respondents, 200 in each state, participated in the study. Of these, 76.7% were female, while 23.3% were male. A total of twenty-six (26) leafy vegetables were collected. Twenty-one (21) species are indigenous to the study area, while five (5) species are non-indigenous. Ethnobotanical survey on leafy vegetables from farms and markets revealed that Launaea taraxacifolia, Solanum macrocarpon, Solanum nigrum, Solanum aethiopicum, Solanecio biafrae, Crassocephalum crepidioides and Basella alba are of high medicinal value. They can be used solely or as a recipe with other leafy plants in the treatment of various ailments including malaria, typhoid, blood pressure, stomach disorder, heart diseases and gastrointestinal tract infections. These vegetable species have been neglected and underutilized by humans. Generally, a low degree of consumption, extent of consumption, and cash income capacity was recorded, with exception to the commonly cultivated vegetables. Extracted DNA from the leafy vegetables yielded good-quality DNA; this has been deposited in the DNA bank at the University of Lagos. This study has documented indigenous knowledge on leafy vegetables in southwest Nigeria and contributed towards ex-situ conservation of the species in the DNA bank.&#x0D; Keywords: Leafy Vegetables, Ethnobotany, Genetic Conservation, Indigenous knowledge, Underutilized species","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feeding Habits and Diet Composition of the African Sacred Ibis in Selected Water-Logged Sites in Dar es Salaam, Tanzania","authors":"Jared S. Bakuza, Joyce Ndinadyo","doi":"10.4314/tjs.v49i2.9","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.9","url":null,"abstract":"The African Sacred Ibises Threskiornis aethiopicus are generalist birds that feed on many invertebrates and some vertebrates. However, the diet composition of local T. aethiopicus populations in wetland areas in Dar es Salaam Tanzania was unknown. Sacred Ibises from eight water-logged areas in Dar es Salaam City, Tanzania were studied to determine their feeding habits and diet composition using direct observations and molecular analysis of faecal samples. Snails species identified from sites frequented by T. aethiopicus included Lymnaea natalensis (61.62%), Melanoides tuberculatus (20.64%), Bulinus sp. (17.66%) and Anisus sp. (0.08%), while molecular analysis of the birds’ diet revealed presence of mostly non-native invasive molluscs (Physa acuta, Planorbella trivolvis and Radix natalensis), fungus (Candida parapsilosis) and protozoan ciliate (Vorticella striata). There was no significant association between bird and snail abundance (r = 0.2141, p > 0.05, ns) although snail diversity showed strong negative relationship (r = -0.7904, p < 0.05). Our findings indicate that the African Sacred Ibises do not preferentially feed on snails, but do so as part of their broader diet. The results confirm that the African Sacred Ibis is a generalist feeder and therefore, ecological impacts of its feeding strategies particularly on invasive snails should be further investigated.&#x0D; Keywords: African Sacred Ibis, feeding, diet, molluscs, generalist","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Epidemiology of Antibiotic Resistance among Escherichia coli Isolated from Broiler Chickens Sold at Selected Markets in Dar es Salaam, Tanzania","authors":"Abdilahi H. Kiula, Victor A. Makene","doi":"10.4314/tjs.v49i2.13","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.13","url":null,"abstract":"Unwarranted and improper uses of antibiotics in broiler farms contribute to the challenge of antibiotic resistance, making even previously treatable infections, difficult to treat. We conducted a cross sectional study from November 2021 to May 2022 from broiler chicken markets in four districts of Dar es Salaam to determine the extent of antibiotic resistance among E. coli isolates from broiler chickens. A total of 160 E. coli isolates recovered from cloacal swabs were identified by culture and biochemical tests and confirmed by Polymerase Chain Reaction (PCR) assays. Antimicrobial susceptibility testing, targeting seven classes of antibiotics, was performed by disk diffusion method and eleven representative antimicrobial resistance markers corresponding to each antibiotic class were screened by PCR. The highest resistance was found against trimethoprim (75%) and erythromycin (74.37%), while the most common resistance gene was dfrA1 (74.37%) and blaTEM (73.75%). The study also found a high prevalence of multidrug-resistant isolates (84.4%) from at least three antibiotic classes. The results highlight the significant contribution of poultry farming to the spread of antibiotic resistance, with potential consequences for both farmers and human health. Prompt measures are necessary to protect human and animal health..","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Roasting Conditions on the Proximate Composition and Functional Properties of Common Bean (Phaseolus vulgaris) Flours","authors":"Rachel Byarugaba, Agnes Nabubuya, John Muyonga, Ali Mwakha","doi":"10.4314/tjs.v49i2.23","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.23","url":null,"abstract":"Roasting of dry beans presents the possibility of a value-added product with improved nutritional quality and potential use in different food systems. The effect of roasting on the proximate composition and functional properties of dry beans (Phaseolus vulgaris L.) was determined. Beans were roasted at 140, 170, and 200 °C for 5, 10, and 15 minutes. The moisture, carbohydrate, protein, dietary fibre, total ash and fat contents of the flours ranged from 4.58 to 6.72%, 56.21 to 60.51%, 23.09 to 26.74%, 4.12 to 7.01%, 3.94 to 4.58% and 1.28 to 2.10%, respectively. An increase in roasting temperature and time significantly reduced moisture and carbohydrate contents, but increased fat, fibre and ash contents. Foaming capacity, foam stability, water absorption index, water solubility index and water absorption capacity varied from 6.16 to 45.14%, 2.10 to 30.68%, 4.20 to 5.12 g/g, 10.74 to 17.15 g/g and 1.77 to 2.2 g/g, respectively. Increasing roasting temperature and time impacted functional properties of flours. Pasting properties of bean flour pastes were significantly reduced. Flour from roasted beans (FRBs) can serve as a functional ingredient and nutrient enhancer in the food industry. In order to increase shelf life and nutrient density of bean flours, the beans should be roasted at 200 °C.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Antidiabetic Activities of Cu(II) Complex of Anacardium occidentale Leaves Crude Extract","authors":"Mary Adelaide Oladipo, Folasade Omobolanle Ajao, Adewusi John Adepoju, Kayode Taiwo Ishola, Deborah Omowumi Afolabi","doi":"10.4314/tjs.v49i2.3","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.3","url":null,"abstract":"Many synthetic chemical drugs have been widely used for the treatment of diabetes. However, many of these drugs are not locally available, are less effective, and are unaffordable for many diabetic patients in developing and underdeveloped countries. Therefore, in order to search for a locally available, effective, and cost-effective antidiabetic agent, this study synthesized the Cu(II) complex of crude leaf extract of Anacardium occidentale and investigated its antidiabetic activity in alloxan induced albino rats. The leaf crude extract and its metal complex were characterized using atomic absorption spectroscopy (AAS) and infrared (IR) spectroscopy. Experimental diabetic animals were induced by a single intraperitoneal injection of alloxan monohydrate at a single dose of 140 mg/kg body weight (b.wt.), and animals with fasting blood glucose levels (BGL) > 200 mg/dl were considered diabetic. Metformin was used as a standard drug. Fasting blood glucose level (BGL) and body weight were examined in assessing the antidiabetic activities of the crude extract and its complex in the rats. One-way ANOVA was used to determine the antidiabetic activity at a statistical significance level of p < 0.05. The hypsochromic shifts of C=O and O-H bands in the Cu(II) complex and the high concentration of the metal ion in the metal complex established the coordination of the crude extract with the metal ion. A more significant reduction in the blood glucose level and increase in body weight in alloxan-induced diabetic albino rats was observed when treated with the leaves crude extract and its Cu(II) complex than when treated with the standard drug metformin. It can be concluded that the Cu(II) complex of Anacardium occidentale leaf extract at a dose of 400 mg/kg wt is more effective without abnormal weight gain and could be considered as a potential antidiabetic drug to replace some of the less effective and expensive conventional antidiabetic drugs.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Estimation of Heavy Tails in Non-linear Models","authors":"Josephine N. Onyeka-Ubaka, Olaide Abass","doi":"10.4314/tjs.v49i2.5","DOIUrl":"https://doi.org/10.4314/tjs.v49i2.5","url":null,"abstract":"A generalized student t distribution technique based on estimation of bilinear generalized autoregressive conditional heteroskedasticity (BL-GARCH) model is introduced. The paper investigates from empirical perspective, aspects of the model related to the economic and financial risk management and its impacts on volatility forecasting. The purposive sampling technique was applied to select four banks for the study, namely First Bank of Nigeria (FBN), Guaranty Trust Bank (GTB), United Bank for Africa (UBA) and Zenith Bank (ZEB). The four banks are selected, because their daily stock prices are considered to be more susceptible to volatility than those of other banks within the sampled period (January 2007–May 2022). The data collected were analyzed using MATLAB R2008b Software. The results show that the newly introduced generalized student t distribution is the most general of all the useful distributions applied in the BL-GARCH model parameter estimation. It serves as a general distribution for obtaining empirical characteristics such as volatility clustering, leptokurtosis and leverage effects between returns and conditional variances as well as capturing heavier and lighter tails in high frequency financial time series data.","PeriodicalId":22207,"journal":{"name":"Tanzania Journal of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}