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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
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Tanzania Journal of Science
Number of Followers: 4  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0856-1761
Published by African Journals Online Homepage  [261 journals]
  • Performance Investigations of the Charging and Discharging Processes in a
           3-Tank Thermal Energy Storage System

    • Authors: Swalehe Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal
      Pages: 727 - 740
      Abstract: The paper presents a 3 tank thermal energy storage system. The system consists of cold oil reservoir, heat storage tank, and a residual drainage tank. Cold oil flows by gravity into a heating chamber and after being heated to the required temperature, a mechanical thermostat opens allowing the hot oil to flow into a heat storage tank. The storage tank was discharged through the cooking unit by boiling 0.5 litres of water. The used oil flowed by gravity to the drainage tank. The discharge flow rates of 0.5, 2.1, 2.8 and 6.5 g/s were considered. A charging efficiency of 51.3% and overall discharging efficiency range of 15.3 34.7% were achieved. Charging efficiency increased when the source was embedded in the storage tank. The instantaneous discharge power had a peak value for each flow rate. The adopted cooking unit had a thermal transfer efficiency range of 34.7 57.6%. A method for sizing oil based TES systems was proposed and illustrated based on the obtained discharge results. Keywords:     3-tank, sizing, discharging, efficiency, thermal energy
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.1
      Issue No: Vol. 48, No. 4 (2022)
  • Phytochemical and Antibacterial Evaluations of Chloroform Extract of
           Mondia whitei (Hook F) skeels

    • Authors: Abdullahi Shehu, Ojochide Inikpi Egwemi , Olufunmilayo Adeola Ajayi, Abdulmumeen Amao Hamid
      Pages: 741 - 746
      Abstract: Mondia whitei, also known as Mondia, is an aromatic plant of Apocynaceae family. It is used as aphrodisiac, antidepressant, fertility medication and to improve appetite. The present study aimed to evaluate the phytochemical and antibacterial properties of the plant. The chloroform extract of M. whitei was screened for its antibacterial effects using agar diffusion method against five bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Salmonella typhi). The extract was active against S. typhi, K. pneumoniae and S. aureus at 400, 400 and 200 mg/mL, respectively. The antibacterial activity of the extract was observed in a dose-dependent manner and was compared with standard antibiotic, ciprofloxacin. The phytochemical screening of the extract revealed the presence of flavonoids, terpenoids, cardiac glycosides, steroids, phlobatannins and phytosterols. The GC-MS analysis of the extract afforded seventeen (17) compounds with major components being n-hexadecanoic acid (23.80%). The exhibited antibacterial activities justify the ethnomedicinal uses of M. whitei root. Keywords: Mondia whitei, GC-MS, Antibacterial activity, Phytochemical
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.2
      Issue No: Vol. 48, No. 4 (2022)
  • Impacts of Climate Change on Small Pelagic Fish Catches in the Coastal
           Artisanal Fishers Communities of Tanzania

    • Authors: Lyidia Kapapa, Paul Onyango, Nibedita Mukherjee, Prosper Mfilinge
      Pages: 747 - 759
      Abstract: Climate-related effects occur across all regions in Tanzania, affecting primary sectors such as agriculture and fishing. This study investigated the impacts of climatic change on small pelagic catches in fishers in Kilindoni, Kipumbwi and Kilwa Kivinje villages along the Tanzanian coast. We studied how changes in rainfall, sea surface temperature, wind speed and chlorophyll a affect small pelagic fisheries using primary and secondary data. Qualitative and quantitative methods were applied. Primary data collection involved questionnaires, focus group discussions and key informant interviews. Secondary data was obtained from Tanzania Meteorological Agency and remote sensing from Modi's sensor. Results showed an increase in sea surface temperature (tau = 0.0151, 0.0121, 0.0238 for Kilindoni, Kilwa Kivinje and Kipumbwi, respectively) and unpredictable changes in rainfall patterns which affected small pelagic fisheries. The average rainfall was 284.6, 97.5 and 56.4 mm in Kilindoni, Kilwa Kivinje and Kipumbwi, respectively. In recent years, rain has been unreliable compared to the past 20 years. Unpredictable rainfall, increased sea surface temperature, wind speed and chlorophyll a had negatively impacted the small pelagic fishery. There was a strong relationship between the decline of small pelagic catches and climatic variables. The findings of this study have implications for coastal fisher's livelihood, income and food security. Keywords:  Coastal communities; small pelagic fishery; climate change; fisheries; livelihood
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
  • Quantifying the Effects of Guessing, Position Bias and Prior Knowledge in
           Multiple Choice Exams

    • Authors: Almasi S. Maguya
      Pages: 760 - 772
      Abstract: “Can an examinee pass a multiple-choice (MC) exam by chance'” Many studies have tried to address this question. However, these studies ignore different types of position bias associated with picking an item from a list. Despite the presence of considerable evidence on the existence of position bias in guessing answers in MC exams, these studies assume an examinee chooses answers with equal probability. This paper seeks to fill this gap by quantifying the chance of success in MC exams due to guessing when different types of position bias and prior knowledge are taken into consideration. The paper proposes a probabilistic model for position bias and uses it to conduct a series of computer simulations for quantifying the chance of passing an MC exam. Results show that the chance of passing an MC exam by pure random guessing is generally negligible even for a poorly set MC exam. Furthermore, resultsshow that chances for an examinee with a fair amount of prior knowledge passing an MC exam of acceptable standard are between very high and perfect. Since a typical examinee is expected to possess some amount of prior knowledge, these results imply that despite their popularity, MCexams should be avoided particularly in high-stake exams where they can lead to false positives. Keywords:     Multiple-choice exams; multiple-choice questions; position bias; computer simulation.
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.4
      Issue No: Vol. 48, No. 4 (2022)
  • Diet of the Golden Jackal (Canis aureus) and Silver-Backed Jackal (Canis
           mesomelas) in the Southern Part of the Serengeti Ecosystem, Tanzania: A
           Comparative Study

    • Authors: Steven E. Temu, Cuthbert L. Nahonyo, Marion L. East , Patricia D. Moehlman
      Pages: 773 - 784
      Abstract: Habitat and food resource partitioning are predicted to facilitate the coexistence of similar-sized carnivores. The golden jackal (Canis aureus) and silver-backed jackal (Canis mesomelas) are similar-sized canids that respectively inhabit grassland and woodland in the Serengeti ecosystem, Tanzania. As information on the diet and food-intake of these two species in this ecosystem is limited, we aimed to compare the diet and food-intake of these canids in the wet and dry seasons, using data from focal samples of foraging behaviour and scat analysis. We predicted dietary differences between these species, seasonal differences within species and peak food intake when breeding. Result of a logistic regression considering insect and small mammal remains in scats revealed dietary differences both between species and within-species seasonal differences. Results of a censored regression model on the estimated weigh of food intake by foraging individuals indicated that intake was highest during the breeding season of each species, which occurs in the wet season in golden jackals and the dry-season in silver-backed jackals. Our study provides new insights on differences in the foraging ecology of these two jackal species in the Serengeti ecosystem. Keywords:    Canis aureus; Canis mesomelas, diet, Serengeti ecosystem, seasons
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.5
      Issue No: Vol. 48, No. 4 (2022)
  • Chemical Analysis, Antibacterial Activities and Uses of Leaves and Calyces
           of Hibiscus sabdariffa Grown in Dodoma, Tanzania

    • Authors: Sartaz Begum, Derick R. Mwakimbwala, Gideon Sangiwa, Valence M.K. Ndesendo
      Pages: 785 - 792
      Abstract: Preliminary phytochemical screening of aqueous and ethanolic extracts of Hibiscus sabdariffa grown in Tanzania revealed the presence of secondary metabolites like steroids, tannins, saponins, glycosides, terpenoids, flavonoids along with L-ascorbic acid (vitamin C) and iron(II). Furthermore, both leaves and calyces showed antibacterial activities (agar well diffusion method) against selected bacterial species (Escherichia coli, Staphylococcus aureus, Salmonella typhi and Shigella sonnei), but calyces possessed potent antibacterial activities compared to leaves. The results also supported the claimed traditional uses of this plant. When interrogated during the cross-sectional study in Dodoma region, 54% of the respondents claimed the plant is used to treat anaemia (supposedly as it increases haemoglobin levels), 23% claimed it is used in the preparation of local wine and the remaining respondents stated use in both areas. Furthermore, the intake of H. sabdariffa leaves and calyces on regular basis can boost the immunity system and helps in preventing bacterial and viral infections as the plant is loaded with flavonoids and vitamin C. Thus, the results observed for the plant H. sabdariffa that is grown in Dodoma in small scale for traditional uses, paves a way for consideration of future large scale production of pharmaceutical and neutraceutical products in Tanzania. Keywords: Phytochemical screening, Hibiscus sabdariffa, antibacterial activity, L-ascorbic acid and iron(II)
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.6
      Issue No: Vol. 48, No. 4 (2022)
  • Enhancing Germination of Seeds of a Multipurpose Tree Species Combretum

    • Authors: Samora Macrice Andrew
      Pages: 793 - 803
      Abstract: Combretum molle R. Br. ex G. Don (Combretaceae) is a highly valued indigenous multipurpose tree species that has gained considerable attention in recent times due to its importance as a medicinal plant as well as an alternative species for wood and charcoal production. However, we lack adequate information on simple and appropriate methods that could be used to break its distinct seed dormancy to support domestication of wild populations apparently undergoing over exploitation and the negative impacts of deforestation. Eight pre-treatment methods involving complete removal of wing, complete removal of mesocarp, overnight soaking in cold water (24 °C) and partial removal of wing by scorching with fire, and their combinations were tested against the seed dormancy. Of all, the complete removal of mesocarp and overnight soaking in cold water followed with additional soaking in cold water for 24 h took the shortest imbibition (2 days) and germination (7 days) periods, highest germination value (76) and germination energy (80%). Similarly, the same treatment scored significantly (P < 0.05) higher cumulative germination of 72%. To obtain best germination traits, C. molle seeds should be pre-treated by removing the mesocarp and overnight soaking in cold water followed with additional soaking in cold water for 24 h, before sowing. These results have wide implications including supporting domestication and forest landscapes restoration in Tanzania. Keywords: Domestication; Restoration; Indigenous species; Dormancy; Lesser known species  
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.7
      Issue No: Vol. 48, No. 4 (2022)
  • Constraining the Origin and Age of the Thermal and Cold Water in the Lake
           Natron Basin, Northern Tanzania

    • Authors: Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai, Mike J. Butler
      Pages: 804 - 815
      Abstract: Springs on the eastern and western shores of Lake Natron Basin (LNB), located within the eastern branch of the East Africa Rift System (EARS) in Northern Tanzania had a discharge temperature that ranged between 34.0 °C and 51.2 °C, while the pH varied from 8.0 to 10.7. The electrical conductivity (EC) ranged between 5,007 µS/cm and 49,200 µS/cm. Cold waters had a temperature of 31.9 °C to 32.5 °C, while the pH ranged between 8.0 and 8.3, and the EC ranged between 1,401 µS/cm and 3,806 µS/cm. The stable isotope composition varied between -2.4 ‰ and -5.3 ‰ for δ18O, and -15.5 ‰ to -29.3 ‰ for δ2H. The isotopic composition of thermal and cold water of LNB indicates a significant contribution of meteoric water in the recharge of the hydrothermal system. However, thermal water is affected by evaporation, water-rock interaction, carbon dioxide (CO2) exchange and condensation processes. Tritium analysis indicated that the spring water in the LNB hydrothermal system has a residence time of more than 50 years. Keywords:    thermal water; Lake Natron Basin; stable isotopes; springs.  
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.8
      Issue No: Vol. 48, No. 4 (2022)
  • Spatiotemporal Variability of Drought and its Relationships to ENSO and
           IOD Indices in Somaliland

    • Authors: Mohamed S. Bile, Paul Limbu
      Pages: 816 - 831
      Abstract: Drought is one of Somaliland’s most prevalent natural hazards, causing serious socioeconomic and environmental harm. This study investigated the spatial and temporal variability of drought and its relationships with El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) indices using the Standardized Evapotranspiration Index (SPEI) from 1981 to 2020. The Mann-Kendall trend test and Sen's slope estimator were used to assess the trends of annual and seasonal SPEI time series. The Empirical Orthogonal Function (EOF) was employed to examine the dominant modes of the SPEI series, and Pearson and partial correlation analyses were performed to investigate the associations between significant modes of drought variability and ENSO and IOD indices. The results demonstrated a statistically significant downward trend of SPEI (increasing drought) at 99% confidence level. The EOF analysis indicated two spatially distinct zones of drought variability in the west and east of the country. Drought variability had a statistically significant negative correlation with ENSO in the summer and winter seasons, and with IOD in the winter season and annual time series. The findings of this study will provide important information for drought risk assessment, mitigation, and predictability in Somaliland. Keywords: Drought, Standardized Precipitation Index, ENSO, IOD, Somaliland
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.9
      Issue No: Vol. 48, No. 4 (2022)
  • Oral Impacts on Daily Performances among People Living with Human
           Immunodeficiency Virus on HAART Era Attending Care and Treatment Clinics
           in Dar es Salaam, Tanzania

    • Authors: Leonard Evarist, Irene Kida Minja
      Pages: 832 - 842
      Abstract: Oral disease/conditions are reported to have negative effects on the quality of life of People Living with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (PLWHIV/AIDS). This study aimed to assess the prevalence and causes of oral impacts on daily performances (OIDP) and its associated factors among PLWHIV/AIDS. A cross-sectional study was conducted among 218 PLWHIV/AIDS attending two HIV Care and Treatment Centres (CTCs) in Dar es Salaam. The study utilized a structured interview schedule containing questions on socio-demography and a single item of global oral health measure on the perception of current oral health status (OHS). A Swahili version of an OIDP inventory was used to assess the impacts of oral conditions on participants’ daily performances. Frequency distribution, chi-square, and logistic regression analyses were conducted (p < 0.05). Participants’ age ranged from 20 to 70 years, mean of 41.15 SD 10.7. About 70% (n = 154) of the participants perceived their oral health status (OHS) as good. The prevalence of OIDP (³ 1) was 26.1% (n = 57). The most affected performances reported were eating and chewing food followed by maintaining the usual emotional state without being irritable. Toothache was the main cause of impacts on all daily performances except ‘speaking and pronouncing clearly’ which was caused by oral ulcer. Age (p = 0.025) and perceived oral health status (p = 0.000) were significantly associated with OIDP. More studies on biological and behavioural factors are recommended to support inclusion of oral health in CTCs. Keywords: Care and Treatment Centres; HAART; HIV; Oral health; Quality of life
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.10
      Issue No: Vol. 48, No. 4 (2022)
  • Antibacterial Potency of Allium sativum, Psidium guajava, Zingiber
           officinale Roots against the Food Poisoning Strains (Escherichia coli
           0157:H7 and Staphylococcus aureus)

    • Authors: Godfrey O. Mauti
      Pages: 843 - 850
      Abstract: Escherichia coli 0157:H7 and Staphylococcus aureus are notorious food poisoning bacteria of great effect on human health. This study determined the phytochemical constituents of ethanolic, vacuum liquid chromatography (VLC) filtrates of Allium sativum (garlic), Psidium guajava (guava), Zingiber officinale (ginger) and their antibacterial activities on E. coli 0157:H7 and S. aureus. In a laboratory-based controlled experiment, the antibacterial and inhibitory activities of the VLC filtrates in doses of 0.01, 0.02, 0.04, and 0.08g/mL were investigated on E. coli 0157:H7 and S. aureus using the agar well diffusion method and compared with a standard antibiotic. The indices of the zone of inhibition on the agar plates were subjected to analysis of variance (p = 0.01). Phytochemical analysis revealed a high concentration of glycosides, steroids, tannins, terpenoids, and the absence of flavonoids in A. sativum. P. guajava root contained a high concentration of glycosides, steroids, tannins, and terpenoids. Z. officinale possessed a high concentration of alkaloids, glycosides, flavonoids, steroids, and terpenoids. Statistically, 0.02 g/mL of Z. officinale (12.0 mm) showed a significant result to 0.04g/mL of A. sativum (14mm) at p = 0.0049 and a higher inhibition index to 0.08g/mL of P. guajava. Inhibition by 0.02g/mL of P. guajava (8.8mm) was advanced than 0.04g/mL of A. sativum (6.3 mm) on S. aureus. Recommendable inhibition of 29.3 mm and 24.0 mm on E. coli 0157:H7 and S. aureus, respectively, were expressed by 0.08 g/mL Z. officinale, which was significant to the standard 0.04 g/mL of Neomycin (Positive control) at p = 0.0067. This study indicated a reliable antibacterial activity by Z. officinale than A. sativum and P. guajava, which might have been due to the high concentration of alkaloids and flavonoids. Nevertheless, A. sativum, P. guajava, and Z. officinale are normally used as fruit and food additives in the human diet, thus can be combined to prevent food poisoning by E. coli 0157:H7 and S. aureus and their exotoxins. Keywords:    Allium sativum, Antibacterial activity, Escherichia coli 0157:H7, Psidium guajava, Staphylococcus aureus, Zingiber officinale
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
  • Impacts of Dietary Chrysophyllum albidum Fruit Pulp on Brain
           Cholinesterase Function in High-Fat Diet/Streptozotocin-Induced Diabetic

    • Authors: Seun Funmilola Akomolafe, Sunday Idowu Oyeleye, Ifeoluwa Adebayo Odeniyi, Iyabo Folake Oladapo, Ayodele Jacob Akinyemi, Folake Lucy Oyetayo , Olubunmi Bolanle Ajayi
      Pages: 851 - 862
      Abstract: Epidemiologic studies have shown strong correlations between Alzheimer’s disease and diabetes mellitus. The exact mechanism through which this happens remains unclear. However, the dependence on glucose for brain function has been proposed as one possible mechanism. Hence, this study investigated the neuroprotective potential of Chrysophyllum albidum fruit pulp (CAPP) with hypoglycaemic properties in diabetic rats induced with high-fat diet/streptozotocin (STZ). The animals were grouped into seven units as follows: control, STZ-induced, STZ + metformin (positive control), STZ + 5% CAPP, STZ + 10% CAPP, control + 5% CAPP and control + 10% CAPP and each group was made up of six rats. The animals were first placed on normal diet (non-diabetic groups) and high fat diet (diabetic groups) for a fortnight, respectively before induction with STZ and were treated with diets containing 5 and 10% CAPP for 14 days. After the experiment, the rat brain cholinesterase and antioxidant activities were determined. The results revealed that acetylcholinesterase (AChE), butylcholinesterase (BuChE), arginase, adenosine deaminase (ADA) and antioxidant activities were altered in STZ-diabetic group in comparison to the control. However, a significant decrease at p < 0.05 was found in the activities of AChE, BuChE, arginase and ADA. In addition, there was a concomitant rise in the levels of antioxidant in all the groups administered supplemented diets and the group treated with metformin in comparison to the STZ-diabetic group. Conclusively, we can suggest that the fruit pulp prevents neurological damage in diabetic rats via anticholinesterase activity and improvement of brain antioxidant status.
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
  • Phytochemical Constituents, Haematological Activities and GC-MS Analysis
           of Isolated Oil of Rosary Pea (Abrus precatorius) in Wistar Rat Fed with
           High Lipid Diet

    • Authors: Osaro Iyekowa, Opara V. Ndubuisi
      Pages: 863 - 874
      Abstract: The study is aimed at investigating the phytochemical constituents and haematological activities of the isolated oil in Wistar rat fed with high lipid diet. Powdered leaves of Abrus precatorious were extracted and phytochemical screening was done according to prescribed standard methods, while vacuum liquid chromatography (VLC) was adopted for oil isolation of the crude extract and characterized by gas chromatography-mass spectrometry (GC-MS). Thirty adult Wistar rats were randomly arranged into six groups (A, B, C, D, E and F) and treated under certain conditions. Haematological analyses were performed according to standard procedures. Saponins, alkaloids, terpenoids, flavonoids and glycosides were present. Oil constituents like octadecanoic acid (stearic acid) (35.30%), a saturated fatty acid was among the components detected in the isolated brown oil. There was a significant decrease (p < 0.05) in the levels of white blood cells (WBC) among the experimental groups (D and E), while mean corpsular haemoglobin (MCH) increased significantly (p < 0.05) with experimental group E (receiving high dose of the extract). This study indicated that methanol extract of A. precatorius can offer protection against blockage or plaques caused by high lipid diet. Keywords: Abrus precatorius, phytochemicals, histology, haematology
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.13
      Issue No: Vol. 48, No. 4 (2022)
  • Knowledge, Attitudes and Practices on Urinary Schistosomiasis-Related
           Morbidity among Communities in Itilima District, Tanzania

    • Authors: Coletha Yohana, Safari M. Kinung’hi, Bruno A. Nyundo, Peter F. Rambau, Jared S. Bakuza
      Pages: 875 - 885
      Abstract: Long-term infections by urinary schistosomiasis can result in urinary tract morbidities and increase the threats to public health. Information on the community’s knowledge, attitudes, and practices (KAP) on various aspects of urinary schistosomiasis, caused by Schistosoma haematobium has been lacking in Itilima District, which is likely to perpetuate the transmission of the disease and its negative health consequences. This study assessed knowledge, attitudes and practices on schistosomiasis-related morbidities in Itilima District from February to June 2021. A cross-sectional survey using a structured questionnaire was used, and a total of 657 participants were involved in the study. A total of 575 participants (87.5%) had awareness on schistosomiasis compared to 82 (12.5%) who were not aware of the disease, and this variation was statistically significant (x² = 369.938, DF = 1, p < 0.001). The relationship between urinary schistosomiasis and its related morbidities was known by 111 (16.9%) respondents, while 546 (83.1%) knew nothing about it, and this variation was also statistically significant (c2 = 388.166, DF = 1, p < 0.001). It can be concluded that knowledge of urinary schistosomiasis and its related morbidities among the communities was limited. This is possibly because knowledge of infection stages of S. haematobium that causes the morbidity requires an understanding of disease etiology. Therefore, this study recommends that interventions to impart knowledge on schistosomiasis and the associated morbidities should be implemented in Itilima District. Keywords:     Schistosomiasis, Urinary tract morbidity, Knowledge, Attitudes and Practices, Itilima District
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
  • Explicit Solutions for Real-time Reversible Inhibition Kinetics using
           Lambert W Function: Towards Progress Curve Analysis

    • Authors: Geradius Deogratias, Makungu Madirisha , Fortunatus Jacob
      Pages: 886 - 896
      Abstract: Accurate estimation of kinetic parameters is challenging due to the dynamics and mathematical nature of the chemical systems. This paper presents simple, yet efficient closed-form solutions for the enzymatic conversion of the substrate to the product in real-time derived using the Lambert W function. The real values of the Lambert W function were calculated from the Lambert package as implemented in MATLAB. The expressions exhibit remarkable robustness in estimating the parameters for randomized data at 1% to 4% variation in noise levels. Furthermore, unlike the initial rates method, the expressions estimate chemical kinetic parameters utilizing a full range of experimental data, thus minimizing the risk of missing information that would be detected at an extended time-span. Thus, the implementation of closed-form solutions presented in this paper for the estimation of kinetic parameters eliminates common pitfalls imposed by the initial rates and double reciprocal methods. Keywords:          Enzyme, Lambert W function, Reversible inhibition, Closed-form solutions
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.15
      Issue No: Vol. 48, No. 4 (2022)
  • Morphological Variabilities and Identification of Yam (Dioscorea spp.)
           Genotypes from Major Growing Regions in Tanzania

    • Authors: Joseph I. Massawe, Gladness E. Temu
      Pages: 897 - 912
      Abstract: Yam (Dioscorea spp.) is a vegetatively propagated crop that belongs to the family Dioscoreaceae. In Tanzania, yam is mainly grown as a source of food and income generation, especially for smallholder farmers. In this study, an assessment of morphological variations among 74 genotypes of Dioscorea spp. collected from six major growing regions was conducted. Yam genotypes were maintained and planted at Tanzania Agricultural Research Institute-Kibaha for characterization. Data from fifty morphological variables were subjected to multivariate analysis using principal component analysis and cluster analysis. The first nine principal components with Eigenvalues > 1 accounted for 86.28% of the total variations. Some traits that contributed to the variabilities include stem length, leaf margin colour, vein colour, absence/presence of wings, wing colour, hairiness, spines on stem base, aerial tubers, and inner skin colour. The dendrogram separated the 74 yam genotypes into two major clusters with six sub-clusters. Based on the results, four yam species were identified from the collected genotypes, and these included D. alata, D. bulbifera, D. cayenensis, and D. dumetorum. The results revealed high morphological variabilities among the yam genotypes. Information obtained in this study is very useful in yam breeding programs in Tanzania. Keywords: Cluster analysis, multivariate analysis, phenotypic variabilities, yam in Tanzania
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
  • Application of MobileNets Convolutional Neural Network Model in Detecting
           Tomato Late Blight Disease

    • Authors: Richard C Rajabu, Juma S Ally, Jamal F Banzi
      Pages: 913 - 926
      Abstract: Late blight (LB) disease causes significant annual losses in tomato production. Early identification of this disease is crucial in halting its severity. This study aimed to leverage the strength of Convolutional Neural Networks (CNNs) in automated prediction of tomato LB. Through transfer learning, the MobileNetV3 model was trained on high-quality, well-labeled images from Kaggle datasets. The trained model was tested on different images of healthy and infected leaves taken from different real-world locations in Mbeya, Arusha, and Morogoro. Test results demonstrated the model's success in identifying LB disease, with an accuracy of 81% and a precision of 76%. The trained model has the potential to be integrated into an offline mobile app for real-time use, improving the efficiency and effectiveness of LB disease detection in tomato production. Similar methods could also be applied to detect other tomato infections. Keywords:  MobileNets; convolutional neural networks; plant diseases detection; image classification; transfer learning
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.17
      Issue No: Vol. 48, No. 4 (2022)
  • Determination of Sugars, Amino Acids, pH and Alcohol in Bamboo Beverage
           from Southern Highlands, Tanzania

    • Authors: Lilian D. Kaale
      Pages: 927 - 941
      Abstract: The amounts of sugars and amino acids play significant roles in defining the fermentation process and quantifying the alcohol levels in beverages, while pH affects the biological stability, colour, oxidation rate, and protein stability of alcoholic beverages. This study investigated the sugar content, amino acids, alcohol levels, and pH of bamboo beverage from Tanzania's southern highlands. During storage, the sugars significantly decreased (p < 0.05), especially when kept at room temperature from 52.96 to 0.00 (source 1), 53.35 to 0.00 (source 2) and 53.57 to 0.00 (source 3) g/L for fructose, from 47.93 to 14.78 (source 1), 47.23 to 14.91 (source 2) and 47.61 to 14.77 (source 3) g/L for glucose, and from 0.40 to 0.00 (source 1), 0.36 to 0.00 (source 2) and 0.37 to 0.00 (source 3) g/L for sucrose after six days of storage. A total of 15 amino acids were determined from the bamboo beverage with tyrosine being the most prevalent (597.68 mg/L for source 1, 599.44 mg/L for source 2 and 597.83 mg/L for source 3), followed by valine (261.13 mg/L for source 1, 261.24 mg/L for source 2 and 262.54 mg/L for source 3), threonine (76.69 mg/L for source 1, 76.91 mg/L for source 2 and 77.13 mg/L for source 3), and serine (66.37 mg/L for source 1, 67.23 mg/L for source 2 and 66.68 mg/L for source 3). After six days of storage at room temperature, there was a significant decrease in pH from 4.04 to 3.63. Alcohol content ranged from 3.11 to 9.05% v/v at the room temperature storage. These results might facilitate the optimal use of bamboo beverages, which have been neglected due to lack of scientific information such as amino acid and sugar levels. Keywords:  Bamboo beverage, ulanzi, amino acids, sugars, alcohol content
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.18
      Issue No: Vol. 48, No. 4 (2022)
  • Mineralogical and Physicomechanical Characterization of Kaolinitic Clay
           from Moshi, Northern Tanzania for Potential Ceramic Utilization

    • Authors: Samwel Paul Mziray, Harieth Hellar-Kihampa, Esther Jason Lugwisha, Leonard Douglas Akwilapo
      Pages: 942 - 953
      Abstract: Kaolin clay from Moshi, northern Tanzania has been characterized for potential ceramics productions. Clay samples taken from three different levels of the deposit were analysed by XRD and XRF. Firing experiments were carried out on experimental briquettes at a maximum temperature of 1300 °C at the rate of 100 °C/hour. The results revealed dominance of kaolinite and illite in the raw clay. The samples were composed majorly by silica (36.88–41.62%), alumina (30.83–32.40%) and hematite (9.29–12.70%). Granulometric analysis showed that the amount of clay decreased with deposit depth. The physicomechanical properties of the clay fired at the optimal temperature of 1300 °C included shrinkage (22.06–30.72%), water absorption (18.23–20.15%), bulk density (1.834–2.182 g/cm3) and modulus of rupture (2.957–6.313 MPa). Mullite was the key component responsible for mechanical strength. Clay sample from the top level showed the best properties. The parameters were of satisfactory quality and comparable to other ceramically suitable clays. High levels of Fe2O3 (> 9%) could adversely affect the translucency of whitewares. These findings indicate that the investigated kaolin has potential of being used in the ceramic industry for making materials such as non-vitreous tiles, bricks and various high-temperature products that do not require high brightness specifications.
      Keywords: Clay mineralogy, firing temperature, microstructure characterization, ceramic properties, Tanzanian kaolin.
      PubDate: 2022-12-30
      DOI: 10.4314/tjs.v48i4.19
      Issue No: Vol. 48, No. 4 (2022)
  • Effects of Long Acting Oxytetracycline on Contagious Bovine
           Pleuropneumonia Experimentally Infected Cattle

    • Authors: Beatrice Otina, Philip Kitala, Lilly Bebora, Moses Olum, Alexander Kipronoh, Lizzie Chesang, Kristin Stuke, Hezron Wesonga
      Pages: 954 - 961
      Abstract: Contagious bovine pleuropneumonia is an important disease of cattle. Many strategies employed for its eradication and control have had shortcomings. This study was conducted to determine the effects of long acting Oxytetracycline on its course. The study involved 30 indigenous zebu cattle sourced from an area free of the disease, infected by contact transmission and randomly allocated to Oxytetracycline or saline treatment groups. Clinical observations were recorded on the two groups concurrently. Cattle were tested for the disease using complement fixation test. The mean clinical scores of the groups for each observation was compared post treatment on GENSTAT using unpaired t-test for single sample in groups. Full post-mortem was conducted on the cattle and samples collected for Mmm SC isolation. The clinical scores were worse in the control treatment group; there was no fever in the Oxytetracycline-treated group post treatment. Lesions were observed in 93% of the control and 27% of the Oxytetracycline-treated group. In this study, as in others, Oxytetracycline was shown to lower the severity of the clinical signs of the disease. This is important at slaughter houses meat inspection where decision on whether to pass or condemn the animal is based on the clinical signs and post-mortem findings. Keywords:  Contagious bovine Pleuropneumonia, Oxytetracycline, Bovine respiratory distress, Trans- boundary diseases
      PubDate: 2022-12-31
      DOI: 10.4314/tjs.v48i4.20
      Issue No: Vol. 48, No. 4 (2022)
  • Spatial Analysis of Groundwater Potential: A first hand Approach towards
           Groundwater Development in Moroto District, Uganda

    • Authors: Musa W. Lowot, Augustina C. Alexander
      Pages: 962 - 972
      Abstract: Groundwater is a vital resource that helps mankind and development. However, in Moroto District challenges of groundwater development has increased arising from changes in rainfall patterns coupled with high abstraction from population increase. In this study, the spatial variability of groundwater potential was assessed to develop a tool that will aid decision on groundwater potential sites selection for groundwater development/exploration. The study utilized an integrated technique and tools such as Remote Sensing (RS), Geographic Information System (GIS) and Multi Criteria Decision Analysis (MCDA) in analysis and delineation of potential areas for successful groundwater development. The generated map through weighted overlay of thematic layers (slope, soil, lithology, rainfall, land use and land cover) produced five categories of potential zones indicating 90% (i.e., 35% very high, 40% high and 15% moderate) of the study area to be suitable for groundwater development and only 10% (i.e., 2% poor and 8% very poor) exists as poor groundwater potential zones. Maps produced from this study can hence be used to identify appropriate sites for groundwater development, and therefore minimizing unsuccessful boreholes development. Keywords:    GIS; Groundwater Development; Groundwater Potential; MCDA; Spatial Analysis.
      PubDate: 2022-12-31
      DOI: 10.4314/tjs.v48i4.21
      Issue No: Vol. 48, No. 4 (2022)
  • Antimalarial and Antimicrobial Activities of some Heteroleptic Metal(II)
           Complexes of Sulfadiazine–Vitamin C: Synthesis and Spectroscopic Studies

    • Authors: Ikechukwu P. Ejidike, Mercy O. Bamigboye, Dorcas A. Fadare, Juliana B. Adetunji, Joshua A. Obaleye
      Pages: 973 - 984
      Abstract: Some new Ni(II), Zn(II), Co(II), Cu(II), and Cd(II) of mixed Sulphadiazine and Vitamin C complexes have been synthesized and characterized by different spectroscopic techniques such as FT-IR, elemental analysis, molar conductivity, and magnetic measurements. Both ligands used for this research work act as bidentate ligands towards the central metal ions coordinating through the nitrogen atoms of >C=N-, NH2 groups of Sulphadiazine and oxygen atoms of OH, CO groups of Vitamin C. Tetrahedral and square-planar geometries have been proposed for the complexes. The complexes are stable under atmospheric conditions. The ligands and their complexes were screened for antimicrobial activities against some isolated organisms: Klebsiella pneumoniae, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis to evaluate their microbial inhibiting potential. The derived complexes were found to exhibit an increased inhibitory action against the organisms when compared to the free ligands. The percentage reduction in parasitaemia for the compounds was also evaluated against Plasmodium berghei. In this realm, [Cd(Su)(Vit)]Cl2 showed the highest activity (89%) as compared to other compounds: Sulphadiazine, Ni(II), Zn(II), Co(II), and Cu(II) complexes are 70, 50, 81, 76, and 77%, respectively, Vitamin C showed no activity. Keywords: Sulfadiazine, Antimalarial, Vitamin C, Physicochemical, Metal-drug complexes, Antimicrobial
      PubDate: 2022-12-31
      DOI: 10.4314/tjs.v48i4.
      Issue No: Vol. 48, No. 4 (2022)
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