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Pesticide sensitivity of Nothobranchius neumanni, a temporary pond predator with a non-generic life-history
Get PDFThis research article was published by Elsevier in Volume 291, Part 1, March 2022Pesticides are crucial to improve agricultural productivity, but often adversely affect surrounding aquatic systems and their fauna. To determine the environmental risk of pesticides, routine ecotoxicological tests are performed on several organisms, including standard fish models. However, these typically do not include fish species from variable habitats and with non-generic life-histories. In particular, inhabitants from temporary ponds such as annual killifish are conventionally understood to be resilient to natural stressors which could translate to higher pesticide resistance or, alternatively, trade-off with their resistance to pesticides and render them more sensitive than classic fish models. Using standard exposure tests, we assessed short-term toxicity effects of two commonly used pesticides, Roundup and cypermethrin, on the annual killifish Nothobranchius neumanni, and compared its sensitivity with that of classic fish models. For Roundup, we found a 72 h-LC50 of 1.79 ± 0.11 mg/L, which is lower than the values reported for zebrafish, medaka, fathead minnow and rainbow trout, suggesting that N. neumanni is more sensitive to the compound. The opposite was true for cypermethrin, with a 72 h-LC50 of 0.27 ± 0.03 mg/L. However, these LC50-values do not deviate strongly from those reported for other fish species, supporting earlier findings in the congeneric N. furzeri that the sensitivity of annual killifish to pollutants is similar to that of classic fish models despite their assumed robustness to environmental stress
Multiple anthropogenic pressures challenge the effectiveness of protected areas in western Tanzania
Get PDFThis research article was published by John Wiley & Sons, Inc. in 2022Despite being key conservation instruments, the ecological effectiveness of protected areas (PAs) is contested. To assess the ecological effectiveness of PAs in the Katavi-Rukwa Ecosystem (KRE) in western Tanzania, we investigated temporal changes in land-use and population densities of six large mammal target species (elephant, buffalo, giraffe, zebra, topi, and hartebeest) across areas with different conservation category, ranging from unprotected to strictly protected. During six survey periods between 1991 and 2018, we analyzed data from remote sensing and aerial wildlife surveys to derive (i) spatiotemporal patterns of cropland cover in relation to protection category; (ii) population densities of the six-target species; and (iii) distribution of these species across protection category, land-use and environmental variables. During the surveyed period, cropland increased from 3.4 % to 9.6 % on unprotected land and from ≤0.05 % to <1 % on protected land. Wildlife densities of most, but not all target species declined across the entire landscape, yet the onset of the observed wildlife declines occurred several years before the onset of cropland expansion. Logistic regression models indicated that target species preferred the national park over less strictly PAs and areas distant to cropland. As our data do not support a direct link between land-use change and wildlife densities, additional factors may explain the apparent ecosystem-wide decline in wildlife. To bolster wildlife conservation in the KRE, we recommended proactive strategies to reduce direct threats to wildlife and cropland expansion toward wildlife dispersal areas and migratory corridors
IOT BASED MONITORING AND REPORTING SYSTEM FOR DOSIMETER WEARERS IN RADIATION AREAS: A CASE STUDY OF TAEC
No full textA Project Report Submitted in Partial Fulfillment of the Requirements of the Award of
the Degree of Master of Science in Embedded and Mobile Systems of The Nelson
Mandela African Institution of Science and Technology.In today's modern society, the use of radiation sources in a wide range of activities has
increased rapidly. As a result, occupational exposure to ionizing radiation doses that cause
health effects increases. Excessive doses of 20 millisieverts (mSv) per year cause acute effects
such as sterility or cancer. The health effects of ionizing radiation fall in many countries around
the world, including Tanzania. Tanzania Atomic Energy Commission (TAEC) manages
dosimeters in order to reduce radiation hazards to radiation workers. Nonetheless, after
dispatching those dosimeters, the TAEC management room is unable to determine whether or
not each supposed wearer has worn the dosimeter. This originates from an incorrect assessment
of an individual occupational radiation dose. Therefore, an Internet of Things-based
Monitoring and Reporting System for Dosimeter Wearers in Radiation Areas is developed.
Using internet of things (IoT) technology, this project presents an effective and affordable
system for real-time remote monitoring and reporting staff wearing passive dosimeters while
near or in the area; radiation exposure is too high. The scrum method, which is based on agile
methodology, was used for system development. The system was run by an ESP32
microcontroller board that was programmed in C using the Arduino Integrated Development
Environment. The ESP 32 microcontroller could send data to the weber server via its built-in
Wi-Fi. Through the mapping web application, the end-user (TAEC Managerial Officer)
monitored and visualized radiation workers. IoT enabled the dosimeter to be monitored and
reported on at any time via the internet
The role of anthropogenic container habitats as mosquito oviposition habitats in rural settlements in northern Tanzania
Get PDFThis research article was published by Journal of Vector Ecology 47(1), 69-80,Abstract
In many areas, the main sources of mosquito vectors are not natural habitats but small artificial water bodies that are provided unintentionally by humans. Such container habitats have been linked to outbreaks of dengue fever and other arboviral diseases. However, in many parts of the world the possible risks associated with container habitats have not been assessed. Here, we focused on a human population expansion area in northern Tanzania with a high incidence of dengue and other cases of high fever. We explored the importance of anthropogenic container habitats for mosquito production in the Lake Manyara Basin. We also assessed how biotic and physicochemical habitat characteristics limit mosquito abundance in containers. Results showed that Aedes aegypti (Linnaeus), vector of dengue and other arboviruses, and Culex quinquefasciatus (Say), vector of filarial worms, were the dominant mosquitoes ovipositing in large numbers in different containers. Old tires were the dominant and most productive container habitat for mosquitoes in the region. However, there were strong differences among villages, illustrating that the mosquito burden associated with container habitats varies locally. We concluded that in this region, removal of artificial container habitats could be a simple strategy to reduce the mosquito-mediated disease burden within the local population
Key Elements of Customer Trust towards Retaining Customers of Telecommunication Companies in Tanzania
Get PDFThis research article was published by Scientific Research Publishing Inc., 2022This study assessed how customer trust affects customer retention in tele communication companies in Tanzania. Using logistic regression, 120 ques tionnaires were analysed. Results revealed respondents were not satisfied
with sustainability operations (83.3%), keeping promises (90%), best tele com services (84.2), business performance (83.3%), stable authority and man agement (82.5%). The percentage of correct predictions of variables ranges
from 80% to 90%. Besides, values of Nagelkerke’s R-square show the ability
of independent variables to account for variation in the dependent variable
from 0.050 to 0.193. Additionally, results from the chi-square analysis were
only statistically significant for the variable age on the sustainability of op erations for age (0.01) and time (0.02). The logistic regression coefficient shows
that time effects operation sustainability negatively by 0.65. For keeping prom ises, predictor age affected the model negatively by 0.07. Moreover, for tel ecom services, predictor variables such as gender and income affected the
model positively by 0.19 and 0.07, respectively. Regarding business perfor mance, age and education negatively affect the model by 0.39 and 0.49, re spectively. Furthermore, on stability of authority and management, predic tor variable gender positively affects the model by 0.23. Thus, telecommu nication companies must ensure customers trust their operations, services,
business performance, and management framework to enhance customer re tention
The effects of extreme climate on the invasive plant Gutenbergia cordifolia: implications for its future management in savannah ecosystems
Get PDFThis research article was published by Heliyon, 2022The aim of this study was to assess the effects of varying water stress levels on morphological and physiological
parameters of an invasive plant Gutenbergia cordifolia. The assessment was conducted in the screenhouse at the
Nelson Mandela African Institution of Science and Technology following a completely randomized design (CRD).
Both morphological and physiological parameters were variable under water stress levels. While the maximum
(159 cm) and minimum (9 cm) plant heights for G. cordifolia were observed under flood and drought water stress
respectively, its maximum root collar diameter of 5 mm and the minimum of 1.3 mm were observed under
moderate flood and drought water stress respectively. Generally, the number of leaves was highest under mod erate flood stress (194 leaves/plant), and lowest under drought stress (13 leaves/plant). Similarly, the largest and
smallest leaf surface area of 9 103 and 1 103
mm2 were observed under flood and drought water stress
respectively due to G. cordifolia's tendency to retain water when exposed to water stress through a reduction in
number of leaves and leaf surface area when under drought stress condition. While a decrease in leaf chlorophyll
was observed across water stress levels with the lowest chlorophyll levels of 0.02 under drought water stress, an
increase in leaf anthocyanin levels (0.29 Abs g.DM 1
) was observed particularly under flood stress due to
increased chlorophyll breakdown and plants' water stress, respectively. This study informs that extreme climatic
events such as excessive floods will likely facilitate invasions by G. cordifolia leading to decreased biotic resistance
of native communities in savanna rangelands. Efforts to manage G. cordifolia's effects in a changing climate must
therefore include the development of strategies and action plans that account for catastrophic events like floods
and drought
A comprehensive review on the decontamination of lead(II) from water and wastewater by low-cost biosorbents
Get PDFThis research article published by Royal Society of Chemistry, 2022The disadvantages of conventional methods in water and wastewater management including the demand
for high energy consumption, the creation of secondary toxic sludge, and operation cost are much too high
for developing countries. However, adsorption using low-cost biosorbents is the most efficient nonconventional technique for heavy metals removal. The high adsorption capacities, cost-effectiveness,
and the abundance of agricultural waste materials in nature are the important parameters that explain
why these biosorbents are economical for heavy metals removal. The present investigation sought to
review the biosorption of lead [Pb(II)] onto low-cost biosorbents to understand their adsorption
mechanism. The review shows that biosorption using low-cost biosorbents is eco-friendly, costeffective, and is a simple technique for water and wastewater treatment containing lead(II) ions. The
batch biosorption tests carried out in most studies show that Pb(II) biosorption by the low-cost
biosorbents is dependent on biosorption variables such as pH of the aqueous solution, contact time,
biosorbent dose, Pb(II) initial concentration, and temperature. Furthermore, batch equilibrium data have
been explored in many studies by evaluating the kinetics, isothermal and thermodynamic variables. Most
of the studies on the adsorptive removal of Pb(II) were found to follow the pseudo-second kinetic and
Langmuir isotherm models with the thermodynamics variables suggesting the feasibility and
spontaneous nature of Pb(II) sequestration. However, gaps exist to increase biosorption ability, economic
feasibility, optimization of the biosorption system, and desorption and regeneration of the used
agricultural biosorbents
Mixed method study to evaluate factors associated with discarding of long-lasting insecticidal nets in Bagamoyo, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Science in Public Health Research of the Nelson Mandela African Institution of Science and TechnologyBetween 2000 and 2019, more than 1.8 billion long-lasting insecticidal nets (LLINs)were
distributed in Africa. While the insecticidal durability of LLINs is around 3 years, nets are
generally discarded 2 years post-distribution. This study investigated the factors associated
with the decision of users to discard LLINs. A mixed-methods sequential explanatory approach
using a structured questionnaire followed by focus group discussions (FGDs) was used to
collect information on experiences, views, reasons, how and when LLINs are discarded as well
as gather knowledge on net care and repair from the participants. Out of 6,526 households that
responded to the questionnaire of LLINs durability trial, 160 households were randomly
selected from the households in four villages in Bagamoyo Tanzania for FGDs but only 155
households participated in the FGDs. Five of the household representatives couldn’t participate
due to unexpected circumstances. A total of sixteen FGDs each comprising of 8-10 adults were
conducted; older women (40–60 years), older men (40-60 years), younger women (18-39
years), and younger men (18-39 years). During the FGDs, participants visually inspected seven
samples of LLINs that were “too-torn” based on the proportionate hole Index (PHI)
recommended by the World Health Organization guidelines on LLIN testing, the nets were
brought to the discussion, and participants had to determine if such LLINs were to be kept or
discarded. The study assessed responses from the same participants that attended FGD and also
responded to the structured questionnaire, 117 participants fulfilled the criteria, thus data from
only 117 participants are analyzed in this study. In FGDs, the Physical condition of LLIN
influenced the decision to discard or keep a net. Those of older age, women and householders
with lower income were more likely to classify a WHO “too-torn” net as “good”. The common
methods used to discard LLINs were burning and burying. The findings were seen in the
quantitative analysis. For every additional hole, the odds of discarding a WHO “too-torn” LLIN
increased [OR=1.05 (95%CI (1.04 – 1.07)), p<0.001]. Younger age group [OR=4.97 (95%CI
(3.25 – 7.32)), p<0.001], male-headed households [OR=6.85 (95%CI (4.44 –10.59)), p<0.001],
and wealthy households [OR=3.88 (95%CI (2.33 – 6.46)), p<0.001] were more likely to discard
LLINs: Physical condition of LLINs was the main determinant for discarding or keeping LLINs
and the decision to discard the net is associated with the socioeconomic status of the household,
and the age and gender of respondents. WHO “too torn” nets are encouraged to be used instead
of none until replaced, and disposal of nets should be based on recommendation
Comparison of cone bioassay estimates at two laboratories with different anopheles mosquitoes for quality assurance of pyrethroid insecticide-treated nets
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Science in Public Health Research of the Nelson Mandela African Institution of Science and TechnologyThis study explored utility of cone bioassays for pre-delivery quality assurance (QA) of pyrethroid
insecticide-treated nets (ITNs) to test the assumption that cone bioassays are consistent across
locations, mosquito strains, and laboratories. Double-blinded bioassays were conducted on 20
pyrethroid ITNs of four brands (100 nets, 5 subsamples per net) that had been delivered for mass
distribution in Papua New Guinea (PNG) having passed pre-delivery inspections. Cone bioassays
were performed on the same net pieces following World Health Organization (WHO) guidelines
at the PNG Institute of Medical Research (PNGIMR) using pyrethroid susceptible Anopheles
farauti sensu stricto and at Ifakara Health Institute (IHI), Tanzania using pyrethroid susceptible
Anopheles gambiae sensu stricto. Results from IHI and PNGIMR were compared using
Spearman’s Rank correlation, Bland-Altman (BA) analysis and analysis of agreement. In cone
bioassays, 13/20 nets (65%) at IHI and 8/20 (40%) at PNGIMR met WHO bio-efficacy criteria.
Results from IHI and PNGIMR correlated on 60-minute knockdown (KD60) (rs= 0.6, p= 0.002,
n=20) and 24-hour mortality (M24) (rs=0.9, p<0.0001, n=20) but BA showed systematic bias
between the results. The agreement between the results to predict ITN failure was good with
kappa=0.79 (0.53-1.00) and 90% accuracy. Based on these study findings, the WHO cone bioassay
is a reproducible bioassay for ITNs with >80% M24, and for all ITNs provided inherent stochastic
variation and systematic bias are accounted for. The 80% mortality (M24) threshold remains the
most reliable indicator of pyrethroid ITN quality using pyrethroid susceptible mosquitoes. In the
absence of alternative tests, cone bioassays could be used as part of pre-delivery QA
Development of the web-based data-driven university information management system (UIMS) for inter-university council for east Africa
Get PDFA Project Report Submitted in Partial Fulfillment of the Requirements of the Award the Degree of Master of Science in Embedded and Mobile Systems of the Nelson Mandela African Institution of Science and TechnologyA significant challenge faced by the Inter-University Council for East Africa (IUCEA) is the
lack of a common Higher Education Information System (HEIS) for the East African
Community (EAC) to harmonize the region's education and training system. The system has to
manage data about the academic program, universities, research, and human capital
respectively developed in different modules. Both EAC's citizens and IUCEA need statistics
regarding this information and complex questions these data may answer. Traditional high
education management is not only costly but also ineffective. In this work, a web-based data driven University Information Management system (UIMS) for IUCEA is designed to
effectively manage university information concerning the academic life cycle, assets, finance,
and human resource. In addition, a university application portal to help high education
institutions is provided to apply for being among all degrees awarding high education. This
system is the second module of the East Africa Community High Education Information
System (EAC HEIS); it has been developed using agile software development and web
technology such as RESTful API, React, Django, and MySQL. UIMS for IUCEA will
significantly impact the IUCEA's day-to-day operation and receive recognition from the surfer.
It will improve the efficiency of many processes