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Open Journal of Geology 2018年第8期8卷 819-840页

作者： Ezekiel J. Seni Gabriel D. Mulibo Giovanni Bertotti Department of Geology University of Dar es Salaam Dar es Salaam Tanzania Department of Geoscience and Civil engineering Deft University of Technology Delft The Netherland

Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in relation to structural styles, sedimentation and hydrocarbon potential evolved in Block 5. Results show that during Early to Late Jurassic, Block 5 was affected by the break-up of Gondwana and the drifting of Madagascar as evidenced by patterns of sediments and structural features. The chaotic and discontinuous reflectors are characteristics features on the sediments pattern indicating a possible transitional setting following the breakup of Gondwana. From the Late Cretaceous, Block 5 sits in more stable subsiding sag as the consequence of the high thermal subsidence. The period displayed continuous parallel reflectors with few markable faults. This was followed by the late post rift sedimentation that occurred after Middle Eocene Unconformity characterized by high wavy and sub parallel reflectors. The evolution of Block 5 through major tectonic events reveals a more complete petroleum system towards the south. Thus, Block 5 responded in both space and time to a complex interplay between tectonics and sedimentation. This indicates that structural styles and associated features are potential control for hydrocarbon generation and migration.

关键词： Offshore Tanzania basin Block 5 Tectonics Sedimentation Hydrocarbon East Africa

The Serological Survey for Human Cysticercosis Prevalence in Mbulu District, Tanzania

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Advances in Infectious Diseases 2012年第3期2卷 62-66页

作者： Beda J. Mwang’onde Gamba Nkwengulila Mwita Chacha Department of Zoology and Wildlife Conservation University of Dar es Salaam Dar es Salaam Tanzania

Human cysticercosis, a zoonotic disease due to Taeniasolium, is of the highly debilitating and stigmatizing neglected tropical diseases due to epilepsy, ophthalmia and dermatological disorders in endemic developing countries. Tanzania is among the sub-Saharan African countries with an average prevalence of porcine cysticercosis 17.2% [1], which increases the risk of human cysticercosis infection. Studies on people with epilepsy in northern zone of Tanzania show a 16.2% [2] to be suffering from neurocysticercosis. While this was the case, there were no single report on the prevalence of human cysticercosis neither to regular hospital visitors, admissions, and nor general public that result to insufficient deployment of intervention strategies. Study was performed to assess the prevalence of human cysticercosis in general public in Mbulu district. The cephalic venous blood was collected from assorted community members. Serum was extracted and then subjected to Cysticercus IgG Western Blot Assay for human cysticercosis sero-screening. It was found that about 16.3% of the community members had antibodies signifying infection by human cysticercosis. This is the first ever study to assess the prevalence of human cysticercosis in the country and it has revealed the problem to be very high. This study can be valuable for deployment of appropriate intervention measures on human cysticercosis in the study area and extend to the entire country.

关键词： Human Cysticercosis Taeniasolium Mbulu-Tanzania Prevalence

Tanzanian rainfall responses to El Nino and positive Indian Ocean Dipole events during 1951-2015

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Atmospheric and Oceanic Science Letters 2021年第6期14卷 41-47页

作者： Dickson Mbigi Ziniu Xiao State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina Department of Physics University of Dar es SalaamDar es SalaamTanzania

The relative impacts of Indian and Pacific Ocean processes on Tanzanian rainfall was evaluated using composite and correlation *** was found that the seasonal responses of rainfall to positive Indian Ocean Dipole(pIOD)and El Nino events are substantial from September-October-November(SON)to December-January-February(DJF),whereas the Indian Ocean Dipole(IOD)exerts more control than El Nino-Southern Oscillation(ENSO)in both *** associated relationship with the sea surface temperature(SST)and large-scale atmo-spheric circulations revealed distinct *** the pure pIOD years,there is above-normal rainfall over the entire country.A strong rainfall condition is evident over the Lake Victoria basin and coastal and northeastern highland parts of the country during SON,while areas of the central and southern highlands exhibit substantial rains during *** the pure El-Nino events,Tanzania has suffered from insignificant,weak,and non-coherent rainfall conditions during ***,a contrasting insignificant rainfall signature is found between the north-ern and southern parts of the country during the subsequent DJF *** the co-occurrence of pIOD and El Nino,significant,excessive rainfall conditions are restricted to over the northern coast and northeastern areas of the country during SON,consistent with the rainfall pattern for pIOD.A weak,positive rainfall condition is observed over the entire country in the following season of ***,in terms of Tanzanian rainfall,the IOD/ENSO variability and the associated impacts can be explained by the anomalous SST and circulation anomalies.

关键词： Rainfall Indian Ocean Dipole El Nino Tanzania

Whole-genome single nucleotide polymorphism and mating compatibility studies reveal the presence of distinct species in sub-Saharan Africa Bemisia tabaci whiteflies

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Insect Science 2021年第6期28卷 1553-1566页

作者： Habibu Mugerwa Hua-Ling Wang Peter Sseruwagi Susan Seal John Colvin Natural Resources institute University of GreenwichCentral AvenueChatham MaritimeKentUK Department of Entomology University of GeorgiaGriffinGeorgiaUSA institute of Insect Sciences Zhejiang UniversityHangzhouChina Biotechnology Department Mikocheni Agricultural Research InstituteDar es SalaamTanzania

In sub-Saharan Africa cassava growing areas,two members of the Bemisia tabaci species complex termed sub-Saharan Africa 1(SSA1)and SSA2 have been reported as the prevalent whiteflies associated with the spread of viruses that cause cassava mosaic disease(CMD)and cassava brown streak disease(CBSD)*** the peak of CMD pandemic in the late 1990s,SSA2 was the prevalent whitefly,although its numbers have diminished over the last two decades with the resurgence of SSA1 *** SSA1 subgroups(SGI to SG3)are the predominant whiteflies in East Africa and vary in distribution and biological *** compatibility between SSA1 subgroups and SSA2 whiteflies was reported as the possible driver for the resurgence of SSA 1 *** this study,a combination of both phylogenomic methods and reciprocal crossing experiments were applied to determine species status of SSA1 subgroups and SSA2 white-fly *** analyses conducted with 26548205 bp whole genome single nucleotide polymorphisms(SNPs)and the full mitogenomes clustered SSA1 subgroups together and separate from SSA2 *** incompatibility between SSA1 subgroups and SSA2 further demonstrated their distinctiveness from each *** analyses conducted with SNPs and mitogenomes also revealed different genetic relationships among SSA1 *** former clustered SSA 1-SGI and SSA1-SG2 to-gether but separate from SSA1-SG3,while the latter clustered SSA1-SG2 and SSA1-SG3 together but separate from SSA *** compatibility was observed between SSA 1-SGI and SSA1-SG2,while incompatibility occurred between SSA 1-SGI and SSA1-SG3,and SSA 1-SG2 and SSA *** results among SSA 1 subgroups were coherent with phylogenomics results based on SNPs but not the full ***,this study revealed that the secondary endosymbiont--did not mediate reproductive success in the crossing assays carried ***,using genome wide SNPs together with reciproca

关键词： Bemisia tabaci phylogenomics reciprocal crossing sub-Saharan Africa species

Teaching Spatial Science Courses in Public Universities in Tanzania: Challenges and Opportunities

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Journal of Geographic Information System 2013年第6期5卷 543-547页

作者： Emiliana John Mwita Geography Department Dar es Salaam University College of Education Dar es Salaam Tanzania

Spatial science courses that are Remote Sensing (RS) and Geographic Information System (GIS) are increasingly growing into extremely important disciplines that accommodate various applications in wider sectors of development. Effective teaching and learning of the courses, however, requires intensive investment in facilities and human resources, since the technology is sophisticated and growing fast. This study aims at exploring the challenges of teaching and learning spatial science courses, RS and GIS, particularly in public universities in Tanzania. The study also identifies possible opportunities to improve the situation. Using social survey techniques in data gathering and analysis and author’s own experience, lack of resources, poor background to the courses, delivery methods, limited number of staff and large classes were seen to be the major obstacles in successful learning and teaching. Opportunities exist in using open source resources, collaboration with other institutions within and outside the country and for the universities to give due weight to the courses by building capacity of their staff and procuring facilities, especially laboratories equipments.

关键词： GIS Remote Sensing Learning Obstacles

Depression,suicidality and associated risk factors among police officers in urban Tanzania:a cross-sectional study

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General Psychiatry 2021年第3期34卷 135-142页

作者： Belinda Jackson Njiro Harrieth Peter Ndumwa Charles Joseph Msenga Thomas Kawala Ezekiel Matola Juhudi Mhonda Hillary Corbin Omary Ubuguyu Samuel Likindikoki School of Medicine Muhimbili University of Health and Allied SciencesDar es SalaamTanzaniaUnited Republic of Medical Unit Tanzania Police ForceDar es SalaamTanzaniaUnited Republic of National NCD Prevention and Control Program Ministry of HealthCommunityDevelopmentGenderElderly and ChildrenDodomaTanzaniaUnited Republic of

Background The WHO has classified depression as a disease of public *** officers are a particular subpopulation group that is at an increased risk for mental health *** study examined the prevalence of depression,suicidality and associated risk factors among police officers in urban *** The aim of this study was to examine the prevalence of depression,suicidality and associated risk factors among police officers in *** A cross-sectional study was conducted between April 2019 and October 2020 among 550 participants in dar es salaam recruited using a multistage cluster sampling *** Patient Health Questionnaire-9 was used to screen for depression and *** Interpersonal Support Evaluation List-12 tool was used to measure perceived social *** statistics were summarised using frequencies and *** and multivariate analyses were used to establish associations between predictors of interest,depression and *** There were 497 participants in the *** these,76.6%(376 of 491)were men,and the median(IQR)age was 37.0(17)*** 19.8%(96 of 486)of the police officers screened positive for depression and 15.4%(75 of 413)for suicidality.A significant proportion was either moderately(29 of 96,30.2%)or severely depressed(8 of 75,10.7%).Of those who experienced suicidal thoughts,10.7%(8 of 75)reported having daily suicidal *** low social support was associated with an increased risk of reporting depression(adjusted OR(aOR):28.04,95%CI:8.42 to 93.37,pession and suicidality among police officers in urban Tanzania is alarmingly *** study findings indicate the need for routine screening for depression and suicidality among police officers and design appropriate mental health responsive services in thi

关键词： routine sectional urban

Analysis of Medical Waste Incinerator Performance Based on Fuel Consumption and Cycle Times

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Engineering（科研） 2012年第10期4卷 625-635页

作者： Samwel Victor Manyele Ignatio Simon Kagonji Department of Chemical and Mining Engineering Collage of Engineering and Technology University of Dar es Salaam P.O. Box 35131 Dar es Salaam Tanzania

A detailed assessment of an incinerator based on fuel consumption and cycle time data is presented in this paper. The study was conducted at Temeke district hospital for 22 months consecutively covering 654 days of daily data collection on fuel consumption and cycle times. The composition for the medical waste incinerated varied between 15% and 35% for sharps waste and between 65% and 85% for other waste, with mean values of 25% and 75%, respectively. The results revealed poor performance of the incinerator due to higher fuel consumption (above 30 L/cycle). The incineration cycle times were observed to range between 2 and 4 hours, all of which were too high for the loading rates observed (55 - 214 kg). A strong dependency of diesel oil consumption on cycle time was observed due to lack of temperature control leading to continuous fuel flow into the burners. The incineration capacity was very low compared to other incinerators in terms of tons per year. This paper gives an insight on the factors affecting incinerator performance assessed based on diesel oil consumption and cycle times. It can be generalized that the incinerator performance was poor due to several factors ranging from poor incinerator design, operator skills, waste management practices, waste storage practices, etc. The hospital was advised to install a new incinerator with short incineration cycle time (30 - 40 minutes) and lower fuel consumption (10 L/cycle) at a loading rate of 200 kg/cycle.

关键词： Waste Combustion Incinerator Performance Medical Waste Incineration Fuel Consumption Incineration Cycle Time Sharps Waste Incinerator Capacity Fuel Effectiveness

Stochastic Dynamics of Cholera Epidemic Model: Formulation, Analysis and Numerical Simulation

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Journal of Applied Mathematics and Physics 2019年第5期7卷 1097-1125页

作者： Yohana Maiga Marwa Isambi Sailon Mbalawata Samuel Mwalili Wilson Mahera Charles Mathematics and Statistics Department Institute for Basic SciencesTechnology and InnovationPan African UniversityNairobiKenya Tanzania Public Service College SingidaTanzania African institute for Mathematical Sciences Dar es SalaamTanzania Jomo Kenyatta University of Agriculture and technology NairobiKenya University of dar es salaam Dar es SalaamTanzania

In this paper, we describe the two different stochastic differential equations representing cholera dynamics. The first stochastic differential equation is formulated by introducing the stochasticity to deterministic model by parametric perturbation technique which is a standard technique in stochastic modeling and the second stochastic differential equation is formulated using transition probabilities. We analyse a stochastic model using suitable Lyapunov function and Itôformula. We state and prove the conditions for global existence, uniqueness of positive solutions, stochastic boundedness, global stability in probability, moment exponential stability, and almost sure convergence. We also carry out numerical simulation using Euler-Maruyama scheme to simulate the sample paths of stochastic differential equations. Our results show that the sample paths are continuous but not differentiable (a property of Wiener process). Also, we compare the numerical simulation results for deterministic and stochastic models. We find that the sample path of SIsIaR-B stochastic differential equations model fluctuates within the solution of the SIsIaR-B ordinary differential equation model. Furthermore, we use extended Kalman filter to estimate the model compartments (states), we find that the state estimates fit the measurements. Maximum likelihood estimation method for estimating the model parameters is also discussed.

关键词： Stochastic Differential Equations Stability Condition Extended Kalman Filter Ito Formula Lyapunov Function Euler-Maruyama Scheme

Trends of Temperature Extreme Indices over Arusha and Kilimanjaro Regions in Tanzania

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Atmospheric and Climate Sciences 2021年第3期11卷 520-534页

作者： Ladislaus Benedict Chang’a Lovina Peter Japheth Agnes Lawrence Kijazi Elisia Hamisi Zobanya Leila Francis Muhoma Meshack Anton Mliwa Jafari Swalehe Chobo Research and Applied Meteorology Tanzania Meteorological Authority Dar es Salaam Tanzania Agrometeorological Section Tanzania Meteorological Authority Dar es Salaam Tanzania Tanzania Meteorological Authority Dar es Salaam Tanzania Climatology and Climate Change Section Tanzania Meteorological Authority Dar es Salaam Tanzania Volunteers Tanzania Meteorological Authority Dar es Salaam Tanzania

The study aimed at analyzing the trends and variability of temperature extremes over the northeastern highlands in Tanzania, specifically over Arusha and Kilimanjaro regions. Quality controlled mean monthly, daily maximum and minimum temperature data for the period 1961 to 2020, obtained from Tanzania Meteorological Authority, were used in the study. Rclimdex and the National Climate Monitoring Products (NMCP) software, developed by the World Meteorological Organization (WMO), were used for

关键词： Climate Extreme Warm Night Cold Night Extreme Temperature Indices NCMP

Hydrodynamics of the Pilot Scale Wet Scrubber with Restricted Outlet Absorbent Flow Rate

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Engineering（科研） 2012年第7期4卷 339-348页

作者： Samwel Victor Manyele Department of Chemical and Mining Engineering College of Engineering and Technology University of Dar es Salaam P.O. Box 35131 Dar es Salaam Tanzania

This paper presents the hydrodynamics of the wet scrubber coupled to a pilot CFB incineration facility. The scrubber was operated using tap water as a scrubbing liquid. The outlet liquid flow rate, Qo, and accumulation rate, Qa, strongly depend on the inlet liquid flow rate, Qin, with different profiles. At higher Qin values, Qo stabilizes, leading to higher Qa and finally flooding. The values of Qa were higher than Qo except for Qin ranging between 0.53 and 0.72 L/s (safe operating range) in which Qa ≌ Qo and Qa = Qin/2. The outlet-to-inlet liquid flow rate ratio, Qo/Qin decreased for Qin > 0.53 L/s. The increase in the accumulation-to-inlet liquid flow rate ratio, Qa/Qin, at higher Qin indicates a change in flow regime towards flooding, accompanied by an abrupt increase in the height of accumulating liquid, Ha. The difference between Qa/Qin and Qo/Qin (denoted as, ΔQao/Qin), shows a minimum close to zero in the safe operating range. The gas flow rate towards the wet scrubber had slight effect on Qo and Qa when Qin was maintained constant. The ratio Qo/Qin decreased slightly with Ha/Ht irrespective of gas velocity. Changing the liquid-to-gas ratio, L/G and Qin strongly affects the maximum and minimum values of Qo/Qin and Qa/Qin.

关键词： Wet Scrubber Liquid Accumulation Rate Liquid Accumulation Level Outlet Liquid Flow Rate Liquid-to-Gas Ratio Valve Opening Position Incineration