Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (102)
- Mathematics (57)
- Life Sciences (32)
- Computer Sciences (18)
- Medicine and Health Sciences (18)
-
- Public Health (17)
- Applied Mathematics (15)
- Biology (11)
- Earth Sciences (11)
- Plant Biology (9)
- Plant Sciences (9)
- Ecology and Evolutionary Biology (8)
- Engineering (8)
- Geology (8)
- Electrical and Computer Engineering (7)
- Physics (6)
- Agriculture (3)
- Atmospheric Sciences (3)
- Environmental Sciences (3)
- Hydrology (3)
- Oceanography and Atmospheric Sciences and Meteorology (3)
- Microbiology (2)
- Oil, Gas, and Energy (2)
- Power and Energy (2)
- Animal Studies (1)
- Applied Statistics (1)
- Artificial Intelligence and Robotics (1)
- Chemistry (1)
- Databases and Information Systems (1)
- Disease Modeling (1)
Articles 91 - 120 of 127
Full-Text Articles in Entire DC Network
Modelling Road Traffic Accidents Counts In Tanzania: A Poisson Regression Approach, Thadei Sagamiko, Nyimvua Mbare
Modelling Road Traffic Accidents Counts In Tanzania: A Poisson Regression Approach, Thadei Sagamiko, Nyimvua Mbare
Tanzania Journal of Science
Road traffic accidents have become serious threats to Tanzanians in recent years. The outcryemanates from the increasing prevalence of negative effects of accidents on human lives,properties, environments and the economy. Poisson regression model was used to study therelationship between road accidents and the factors facilitating them in Tanzania. Count data onyearly road traffic accidents for Tanzania covering the period 1993 to 2019 were used. Due toover-dispersion of Poisson regression model, quasi-Poisson regression model was found the mostappropriate approach for the analysis of these data. Results indicated that all predictors aresignificant under Poisson regression model with p-value less than 0.05 but …
Campylobacteriosis Transmission Dynamics In Humans: Modeling The Effects Of Public Health Education, Treatment, And Sanitation, Furaha Chuma, Zubeda Mussa
Campylobacteriosis Transmission Dynamics In Humans: Modeling The Effects Of Public Health Education, Treatment, And Sanitation, Furaha Chuma, Zubeda Mussa
Tanzania Journal of Science
An epidemic model for the dynamics of campylobacteriosis disease with public health education, treatment, and sanitation control strategies was formulated and analyzed. The stabilities of the equilibrium points were analyzed by using the Routh-Hurwitz criterion. The effective reproduction number was computed by using the Next Generation Matrix method. Numerical simulations were carried out and the results showed that, public health education has a substantial influence on the reduction of the effective reproduction number. Moreover, treatment and sanitation control strategies have also shown significant reduction of infected individuals from the respective population.Keywords: Campylobacteriosis; public health education; treatment; sanitation.
Capacity Analysis Of A Television White Space Network Deployed Under Distance Distribution Approach, Moses Ismail, Mussa Kissaka, Prosper Mafole
Capacity Analysis Of A Television White Space Network Deployed Under Distance Distribution Approach, Moses Ismail, Mussa Kissaka, Prosper Mafole
Tanzania Journal of Science
Television White Space (TVWS) is currently a leading technology for broadband connectivity in rural areas due to its penetration capability and robustness to attenuation and fading. Since most rural areas where TVWS is suitable are characterized by sparse population distribution, a deployed network must be adequately planned to provide the required coverage while meeting the targeted quality of service. This paper modelled and analyzed the capacity of a TVWS suitable for sparsely populated settings. The TVWS network was modelled using the distance distribution approach, and capacity simulation was carried out through Matlab. Results showed that, at the signal quality of …
A Model For Mapping Combined Effects Of Quality Of Service Parameters And Device Features On Video Streaming Quality Of Experience, Beatrice Buberwa, Mercy Mbise
A Model For Mapping Combined Effects Of Quality Of Service Parameters And Device Features On Video Streaming Quality Of Experience, Beatrice Buberwa, Mercy Mbise
Tanzania Journal of Science
Maintaining quality of streaming video is challenged by network faults resulting into freezes and rebufferings on the video. On top of the network effects, device features have impacts on the image of the video frames displayed during streaming. Despite the simultaneous impacts of video quality from network and device, previous studies considered individual impact of network parameters or devices as influencing factors to propose Quality of Experience (QoE) models. This study proposed QoE model by mapping combined effects from both network and device on video streamed QoE. An experiment to study the effects of video quality from combined effects of …
Mobile Pedestrian Navigation Framework For Multi-Factors Resources Allocation, Joseph Mushi, Baraka Jungwa
Mobile Pedestrian Navigation Framework For Multi-Factors Resources Allocation, Joseph Mushi, Baraka Jungwa
Tanzania Journal of Science
Although it is possible for pedestrian to walk to unfamiliar places, familiarizing and finding a way out of new environments is quite challenging unless a pedestrian navigation system (PNS) is used. Most existing PNS solutions are employing vehicle navigation framework, however, such systems are designed to work efficiently for vehicular systems and not suitable for finding shortest path in environment with poor geospatial mapping. This study designed pedestrian navigation framework for PNS that supports resource allocations in environment with poor geospatial mapping. Mixtures of qualitative and quantitative methods have been used to interview prospective users for requirement specifications and experimental …
Total And Available Fluoride Content In Toothpastes Sold In Dar Es Salaam, Tanzania, Monica Mbaraka Ndoile
Total And Available Fluoride Content In Toothpastes Sold In Dar Es Salaam, Tanzania, Monica Mbaraka Ndoile
Tanzania Journal of Science
A total of eleven (11) different toothpaste brands (imported and manufactured in Tanzania) sold in Dar es Salaam were evaluated for Total Fluoride (TF) and Total Soluble Fluoride (TSF) concentrations. To protect the subject’s identity, the samples were coded. Four selected toothpastes were analyzed for potentially bioavailable fluoride by examining the relationship between TSF in tooth brushing residues and in that of the toothpaste. The results indicated that measured TF of the toothpaste samples coded as TPSA, TPSC and TPSH were consistent to the one declared by the manufacturers. On the other hand, samples coded as TPSB, TPSD, TPSE, TPSF, …
Sensitivity Analysis And Uncertainty Parameter Quantification In A Regression Model: The Case Of Deforestation In Tanzania, Thadei Sagamiko, Nyimvua Shaban, Isambi S. Mbalawata
Sensitivity Analysis And Uncertainty Parameter Quantification In A Regression Model: The Case Of Deforestation In Tanzania, Thadei Sagamiko, Nyimvua Shaban, Isambi S. Mbalawata
Tanzania Journal of Science
In this paper a multiple regression model for the economic factors and policy that influence the rate of deforestation in Tanzania is formulated. Sensitivity analysis for parameters of explanatory variables using one-at-a time and direct methods is carried out and the model is fitted by classical least square (LSQ) and Markov Chain Monte Carlo (MCMC) methods. Uncertainty quantification of parameters by adaptive Markov Chain Monte Carlo methods is performed. The coefficient of determination indicates that 87% of deforestation rate is explained by explanatory variables captured in the model. Household poverty rate is found to be the most sensitive factor to …
Security Model For Tracking Creation Of Mobile Money Using Transport Layer Security Protocol, Sigsbert Rwiza, Mussa Kissaka, Kosmas Kapis
Security Model For Tracking Creation Of Mobile Money Using Transport Layer Security Protocol, Sigsbert Rwiza, Mussa Kissaka, Kosmas Kapis
Tanzania Journal of Science
Mobile Network Operator (MNO) financial service model has security vulnerabilities in addressing verification of cash and mobile money. For instance, monthly returns are transferred in plain text from banks and MNOs to financial regulators. This may result to failure of financial regulators in detecting creation of fake mobile money. This study was conducted to develop a security model for tracking creation of mobile money using Transport Layer security protocol as a way of protecting returns in transit from banks and MNOs to financial regulators. The proposed model was developed using insights from literature, function decomposition and composition techniques and was …
1-D Transport Behaviour Of Emerging Contaminants In The Unidirectional Flowing Surface Waters Of The Msimbazi River, Hossein Miraji, Eunice Mureithi, Othman Othman, Faustin Ngassapa
1-D Transport Behaviour Of Emerging Contaminants In The Unidirectional Flowing Surface Waters Of The Msimbazi River, Hossein Miraji, Eunice Mureithi, Othman Othman, Faustin Ngassapa
Tanzania Journal of Science
The primary objectives of this investigation of environmental pollution were to assess spatio-temporal concentrations and predictions of transport behaviour of pollutants in aqueous media. In order to attain these goals for the Msimbazi river, the analytical and numerical solutions to the 1-D advection-dispersion equation (ADE) implemented the first-type inlet condition. The MATLAB software was used to solve the analytical equation resulting from the ADE equation. The solution to the ADE model enabled effective prediction of contaminants’spatial distribution within a distance of 200 m from a point source in the direction of flowing water. Among the first and third-types inlet conditions, …
Device–To-Device Association Algorithm For Optimal Neighbour Selection And Channel Sharing In 5g Cellular Networks, Chiza Christophe, Omar Hamad, Libe Massawe, Abdi Abdalla
Device–To-Device Association Algorithm For Optimal Neighbour Selection And Channel Sharing In 5g Cellular Networks, Chiza Christophe, Omar Hamad, Libe Massawe, Abdi Abdalla
Tanzania Journal of Science
The integration of device-to-device (D2D) communication in 5G cellular networks has generated the possibility of multiple transmission modes in a single cell. This has motivated scholars to investigate different mode selection and D2D association algorithms that guarantee the selection of proper transmission mode. However, the complexity of algorithms and tractability of devices in the cell are still remarkably challenging. This paper, therefore, presents a utility based D2D association algorithm that ensures optimal neighbour selection by using numerical linear algebra to minimize computational complexity. Simulation results show that the minimum utility based D2D association increases the expected values of attached devices …
Variability Of Selected Mineral Contents In Marine Fish From Local Markets In Tanzania, Stella Shija, Matobola Mihale, Daniel Shilla
Variability Of Selected Mineral Contents In Marine Fish From Local Markets In Tanzania, Stella Shija, Matobola Mihale, Daniel Shilla
Tanzania Journal of Science
Mineral contents (K, Na, Ca and Mg) in selected marine fish species (Alectis ciliaris, Lethrinus harak, Rastrelliger kanagurta and Siganus canaliculatus) from local fish markets were analysed in wet and dry seasons. The processing methods (frying and boiling) were also assessed for their influence on the mineral contents. Samples were randomly collected from Tanga, Bagamoyo, Dar es Salaam and Mtwara seaports, analysed using established methods and determined by Graphite Furnace Atomic Absorption Spectrometry. Mean mineral contents in individual and all analysed fish species were high during dry season compared to wet season except Ca and the difference was statistically significant …
The Application Of Late Acceptance Heuristic Method For The Tanzanian High School Timetabling Problem, Allen R. Mushi
The Application Of Late Acceptance Heuristic Method For The Tanzanian High School Timetabling Problem, Allen R. Mushi
Tanzania Journal of Science
High School timetabling is the problem of scheduling lessons of different subjects and teachers to timeslots within a week, while satisfying a set of constraints which are classified into hard and soft constraints. This problem is different from university course timetabling problem because of the differences in structures including classroom allocations and grouping of subject combinations. Given the scarce education resources in developing countries, high school timetabling problem plays a very important role in optimizing the use of meager resources and therefore contribute to improvement of quality of education. The problem has attracted attention of many researchers around the world; …
Bayesian Estimation Of Regression Quantiles In The Presence Of Autocorrelated Errors, Ayoade I. Adewole, Olusoga A. F Fasoranbaku
Bayesian Estimation Of Regression Quantiles In The Presence Of Autocorrelated Errors, Ayoade I. Adewole, Olusoga A. F Fasoranbaku
Tanzania Journal of Science
This is a study of Bayesian quantile regression that broadly considered the estimation of regression quantiles in the presence of autocorrelated error. Regression models are based on several important statistical assumptions upon which their inferences rely. Autocorrelation of the error terms violates the ordinary least squares regression assumption that error terms are uncorrelated which invalidate Gauss Markov theorem. This study designed schemes for estimation and making inference of regression quantiles in the presence of autocorrelated errors using Bayesian approach. Bayesian method to quantile regression models regards unknown parameters as random variables and the parameter uncertainty was taken into account without …
Abundance And Distribution Of Afrosteles Distans An Indicator Of Food Availability For The Kihansi Spray Toad (Nectophrynoides Asperginis) In The Kihansi Gorge, Lulu T Kaaya, Rashid A Tamatamah, Timoth B Suya
Abundance And Distribution Of Afrosteles Distans An Indicator Of Food Availability For The Kihansi Spray Toad (Nectophrynoides Asperginis) In The Kihansi Gorge, Lulu T Kaaya, Rashid A Tamatamah, Timoth B Suya
Tanzania Journal of Science
Survivorship of the Kihansi Spray Toad in the wild depends on various factors such as environment, habitat, food availability, diseases and predation. This study assessed the abundance of Afrosteles distans Linnavuori 1959 as an indicator of food availability for the Kihansi Spray Toad. Samples were collected from sprinkled (A, B, C, D, E and F) and non-sprinkled (G and H) plots in the upper spray wetland in the Kihansi gorge during the dry period in 2007, 2008, 2015, 2016 and 2018. There was a significantly higher abundance of A. distans in sprinkled than non-sprinkled plots. ANOVA showed significant differences in …
Modelling And Analysis Of A Holling Type Ii Stage Structured Predator-Prey System In The Presence Of Harvesting, Jacob Lyimo, Nyimvua Shaban, Eunice Mureithi, Thadei Sagamiko
Modelling And Analysis Of A Holling Type Ii Stage Structured Predator-Prey System In The Presence Of Harvesting, Jacob Lyimo, Nyimvua Shaban, Eunice Mureithi, Thadei Sagamiko
Tanzania Journal of Science
The effect of harvesting and predation on a Holling type II stage-structured predator-prey system with assumption that harvesting and predation happen only to mature preys was investigated. Stability of interior point was analysed using Routh Hurwith Criterion. Numerical simulations were carried out. The results show that harvesting and predation have strong negative impacts on population dynamics of stage structured predator-prey system.
Total Electron Content Prediction Model Using The Artificial Neural Networks Over The Eastern Africa Region, Emmanuel D. Sulungu, Christian B.S. Uiso
Total Electron Content Prediction Model Using The Artificial Neural Networks Over The Eastern Africa Region, Emmanuel D. Sulungu, Christian B.S. Uiso
Tanzania Journal of Science
In this paper, development of a model using NN technique for prediction of GPS TEC over the Eastern Africa region is presented. TEC data was obtained from the Africa array and IGS network of ground based dual-frequency GPS receivers from 18 stations within the East African region. It covers approximately the area from ~2.6°N to ~26.9°S in magnetic latitudes and from ~95°E to ~112oE in magnetic longitudes. The input layer of the developed model consisted of seven neurons which were selected by considering the parameters that are known to affect the TECv data. The results showed that when the number …
Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa
Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa
Tanzania Journal of Science
Wind speed data used in this study were from Makambako and were recorded at a height of 10 m. In the analysis, the data were extrapolated to 80 m above ground level and wind speed from July to November were found to have an average value of 17.58 m/s. November was found to be the windiest month for the whole duration while the calm month was found to be March. The wind power density was found to be highest in the month of November for the whole study duration. The months of July to November have higher wind power density …
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
Tanzania Journal of Science
The univariate kernel density estimator requires one smoothing parameter while the bivariate and other higher dimensional kernel density estimatorsdemand more than one smoothing parameter depending on the form of smoothing parameterizations used. The smoothing parameters of the higher dimensional kernels are presented in a matrix form called the smoothing matrix. The two forms of parameterizations frequently used in higher dimensional kernel estimators are diagonal or constrained parameterization and full or unconstrained parameterization. While thefull parameterization has no restrictions, the diagonal hassome form of restrictions.Thestudyinvestigates the performance of smoothing parameterizations of bivariate kernel estimator using asymptotic mean integrated squared error aserror …
Determination Of Radiation Doses To Patients Undergoing Fluoroscopically Guided Orthopaedic Procedures At Muhimbili Orthopaedic Institute In Tanzania, Jacob Busumabu, Ismael N. Makundi, Justin E. Ngaile
Determination Of Radiation Doses To Patients Undergoing Fluoroscopically Guided Orthopaedic Procedures At Muhimbili Orthopaedic Institute In Tanzania, Jacob Busumabu, Ismael N. Makundi, Justin E. Ngaile
Tanzania Journal of Science
The aim of the present study was to determine the magnitude of radiation doses delivered to patients undergoing Fluoroscopically Guided Orthopaedic Procedures (FGOP’s) in Tanzania. The air Kerma Area Product (KAP), fluoroscopy time, organ dose and effective dose to patients undergoing FGOP’s were obtained from Muhimbili Orthopaedic Institute. A total of 72 adult patients from selected three FGOPs namely Lumbar Spine (LS), Dynamic Hip Screw (DHS) and Thoracic Spine (TS) procedures were investigated using C-arm fluoroscopy machine. The knowledge of patient demographic data, radiographic data, KAP and Monte Carlo-based PCXMC software were used to obtain the magnitude of organ doses …
Anempirical Performance Comparison Of Meta-Heuristic Algorithms For School Bus Routing Problem, Sherehe Semba, Egbert Mujuni
Anempirical Performance Comparison Of Meta-Heuristic Algorithms For School Bus Routing Problem, Sherehe Semba, Egbert Mujuni
Tanzania Journal of Science
School Bus Routing Problem is an NP-hard Combinatorial Optimization problem. Thus, mega-heuristic algorithms are widely used to solve instances of the School Bus Routing Problem with large data. In this work we present a model of the School Bus Routing Problem and empirical performances comparison between three meta-heuristic algorithms named Simulated Annealing (SA), Tabu Search (TS) and Ant-Colony Optimization (ACO) on the problem. We have analyzed their performances in terms of solution quality. The results show that all three algorithms have the ability to solve the School Bus Routing Problem. In addition, computational results show that TS performed best when …
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
A Key Note On Performance Of Smoothing Parameterizations In Kernel Density Estimation, Israel U. Siloko, Osayomore Ikpotokin, Edith A. Siloko
Tanzania Journal of Science
The univariate kernel density estimator requires one smoothing parameter while the bivariate and other higher dimensional kernel density estimatorsdemand more than one smoothing parameter depending on the form of smoothing parameterizations used. The smoothing parameters of the higher dimensional kernels are presented in a matrix form called the smoothing matrix. The two forms of parameterizations frequently used in higher dimensional kernel estimators are diagonal or constrained parameterization and full or unconstrained parameterization. While thefull parameterization has no restrictions, the diagonal hassome form of restrictions.Thestudyinvestigates the performance of smoothing parameterizations of bivariate kernel estimator using asymptotic mean integrated squared error aserror …
Indoor Radon Concentration Levels And Annual Effective Doses For Residence Of Houses Near Uranium Deposit In Bahi District, Dodoma, Tanzania, Najat K. Mohammed, Erasto Focus
Indoor Radon Concentration Levels And Annual Effective Doses For Residence Of Houses Near Uranium Deposit In Bahi District, Dodoma, Tanzania, Najat K. Mohammed, Erasto Focus
Tanzania Journal of Science
The objective of this study was to determine the levels of indoor radon concentration in houses in Bahi District situated in the neighbourhood of uranium deposit. The study aimed also to assess the annual effective dose due to indoor radon exposure to individuals residing in the houses as a step to control the radon exposure in Tanzania. Two villages were involved in this study; Bahi Makulu, which is within the proximity of Uranium deposit and Bahi Sokoni, which is about 7 km from the deposit. The Indoor radon concentration levels were detected using Alpha Guard radon monitor and the obtained …
Spatio-Temporal Analysis Of Wetland Change In Port Harcourt Metropolis, Olatunde Sunday Eludoyin, Olalekan Akinola
Spatio-Temporal Analysis Of Wetland Change In Port Harcourt Metropolis, Olatunde Sunday Eludoyin, Olalekan Akinola
Tanzania Journal of Science
The study assessed changes of wetland in Port Harcourt Metropolis using geo-information techniques between 1984 and 2015. Landsat images of 1984, 2000 and 2015 of 30m x 30m resolution were used. Supervised classification was used for image classification using Maximum Likelihood Algorithm in Erdas Imagine 9.1 whereby five major landuse classes were identified namely thick vegetation, built up area, farmland/sparse vegetation, wetlands and waterbodies. Areas in squared kilometers of each landuse were calculated in ArcGIS 9.3 and simple arithmetic was used to compute the percentage change. Probability of landuse change in the next 10, 20 and 30 years was determined …
Trophy Hunting And Trophy Size In Ugalla Game Reserve, Western Tanzania, P Wilfred
Trophy Hunting And Trophy Size In Ugalla Game Reserve, Western Tanzania, P Wilfred
Tanzania Journal of Science
The present paper explores trends and variations in trophy size among wildlife species hunted in the Ugalla Game Reserve (UGR) of western Tanzania, in relation to hunting success (animals shot species-1 quota-1). Data on trophy hunting from 2006 – 2010 were obtained from the UGR office in Tabora Region. Forty-seven species were targeted by trophy hunters. Hunting success differed significantly across the species (Generalised Linear Model [GLM] with a binomial error structure: deviance chi-square [X2] = 9.64, d.f. = 44, p<0.001). Twenty-eight species had trophy size measurements, but only 6 species had measurements taken consistently throughout the data period. Although most of the shot animals were above their minimum trophy size limits (official trophy limits below which animals could not be removed) there was significant variation among species (GLM with normal errors: F5,201 = 509.12, p<0.001). Time (years) had no significant effect on trophy size, but the trend over time in trophy size differed significantly among species (F5,194 = 5.42, p<0.001). Of the trophy species, greater kudu (Tragelaphus strepsiceros) had the largest mean trophy size, whereas warthog (Phacochoerus africanus) had the lowest trophy size and showed a considerable decline. The majority of the animals had trophy sizes hovering just above their minimum limits. This should be monitored rigorously to avoid removing large numbers of actively breeding animals.
Two Phase Heuristic Algorithm For The University Course Timetabling Problem: The Case Of University Of Dar Es Salaam, A. R. Mushi, A. R. Mushi
Two Phase Heuristic Algorithm For The University Course Timetabling Problem: The Case Of University Of Dar Es Salaam, A. R. Mushi, A. R. Mushi
Tanzania Journal of Science
University course timetabling is the problem of scheduling resources such as lecturers, courses, and rooms to a number of timeslots over a planning horizon, normally a week, while satisfying a number of problem-specific constraints. Since timetabling problems differ from one institution to another, this paper investigated the case of the University of Dar Es salaam, based on the combination of Simulated Annealing (SA), and steepest descent in a two-phase approach. Solutions have been generated which greatly outperform the manually generated ones. Furthermore, the method compares well with previous work on Tabu Search but with faster execution time and higher quality …
Formant Analysis For Kiswahili Vowels, Y. Y. Sungita, E. E. Mhamilawa
Formant Analysis For Kiswahili Vowels, Y. Y. Sungita, E. E. Mhamilawa
Tanzania Journal of Science
Vowels' spectral characteristics in a language have been studied for suitability in speech recognition by using formants analysis technique. Other techniques do mostly require large computer memories for speech processing and analysis. In this paper, the formant analysis for Kiswahili vowels has been presented. The spectrographs for each vowel and their respective average formant frequencies are tabled. The distribution of formants for the vowels modelled in the form of an articulatory model is shown. The results show that there is a big separation of formant frequencies among the Kiswahili vowels that signify the suitability for automatic speech recognition.
Occurrence Of Metacercariae Of Diplostomum And Tylodelphys Species (Diplostomidae) In Clarias Species (Clariidae) Fishes From Lake Victoria, M. J. Musiba, G. Nkwengulila
Occurrence Of Metacercariae Of Diplostomum And Tylodelphys Species (Diplostomidae) In Clarias Species (Clariidae) Fishes From Lake Victoria, M. J. Musiba, G. Nkwengulila
Tanzania Journal of Science
The localisation and abundance of the metacercariae of Diplostomum and Tylodelphys species among the clariids of Lake Victoria were investigated between April and December 2001. Four species viz. Clarias gariepinus (271), C. alluaudi (65), C. werneri (50) and C. liocephalus (47) were examined, but only C. gariepinus was infected in the brain case and along the nasal cavity. Prevalence of metacercariae was high (>70%). Prevalence and mean intensity were similar between male and female fish. Mean intensity increased with fish size and declined in larger fish for D. mashonense; but declined with the increase in fish size for Tylodelphys …
Distribution Of Hourly Variability Index Of Sky Clearness, A. Madhlopa
Distribution Of Hourly Variability Index Of Sky Clearness, A. Madhlopa
Tanzania Journal of Science
Clouds affect the values of insolation for solar technology and other applications. To detect the presence of variability in the sky clearness, an hourly variability index (p3) is calculated. The present study examined the frequency distribution of this variable as a tool for assessing the utilizability of solar radiation at a site. Solar radiation data from Chileka weather station in Malawi was used to calculate p3 and mean monthly variability index (p3m) and determine the probability model for each month. It was found that p3m was highest in April (0.20) and lowest in September (0.10), with the beta probability model …
Morphometrics Of The Pancake Tortoise (Malacochersus Tornieri) In Tanzania, J. Kabigumila
Morphometrics Of The Pancake Tortoise (Malacochersus Tornieri) In Tanzania, J. Kabigumila
Tanzania Journal of Science
Observations were made of the morphometrics of captive pancake tortoise (Malacochersus tornieri) in June 1995. Carapace length ranges for immature tortoises and adult males and females were 50-115, 123-160 and 129-171 mm respectively. The respective carapace widths were 45-90, 97-130, and 92-129 and 97-130 mm. Carapace height ranges were 15-29, 25-40 and 117-159 mm, respectively, while plastron length ranges were 45-110, 108-150 and 117-159 mm. The relationships between carapace length and width (males: y = 13.763+0.639x; females: y = 17.302+0.639x) and height (males: y=6.851+0.170x, females: y = 17.274+0.170x) were isometric and sexually dimorphic in adults. The relationship between carapace length …
Experimental Spat Collecting Of The Edible Oyster, Saccostrea Cucullata Born (Bivalvia) In The Kundichi Creek, Dar Es Salaam, Y. D. Mgaya
Tanzania Journal of Science
A one year study was carried out at Kunduchi Creek, Dar es Salaam, to determine spat settlement using the three different substrates (clutches): coconut shells, asbestos and cockle shells, set at three different depths, 0.5 m, 1 m, and 1.5 m. The experiment was set up at three different sites within the creek. There were no significant differences among treatments (sites, depths, clutches). However, spat settlement exhibited seasonal differences, with peak spatfall recorded during the long rains (April to May). There were significant differences in the number of spat between the upper and lower surfaces of the substrates, with more …