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Modelling wildebeest foraging processes and their interaction with zebra and lion in the Serengeti ecosystem
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Mathematical and Computer Sciences and Engineering of the Nelson Mandela African Institution of Science and TechnologyAnimal movements and foraging processes for the migrating species, especially wildebeests and
zebras, and the prey-predator interactions of these prey species with lions are ambiguous
biological characteristics in the Serengeti ecosystem. These complex dynamics help animals to
adapt and survive. To understand such dynamics, investigating factors that determine foraging
efficiency and the prey-predator interaction is worth it. This dissertation presents deterministic
mathematical models to examine wildebeest foraging processes and the prey-predator
interaction of wildebeest, zebra, and lion populations. The first model studies the foraging
processes of migrating wildebeests using the concepts of random walk and diffusive processes.
The model was equipped with data collected from the Serengeti ecosystem from 18 GPS
collared wildebeests and analysed in two spatial dimensions. The qualitative analysis of the
model was performed, and the parameters that regulate foraging efficiency were calculated for
both dry and wet seasons. Numerical simulations were performed, and the results show that
directed movements can explain the great migration of wildebeests to different habitats.
Wildebeests spread across different habitats to utilize the resources through diffusive trends.
The mutual association between wildebeests and zebras was studied by developing the Lotka Volterra reaction-diffusion systems. This model was further modified to form the third model
that includes the predation pressure from lions. The qualitative analyses of the models were
carried out in two dimensions to determine points of equilibrium and the conditions for the
stability and instability of the systems. The explicit Euler method was used to discretize the
models and perform numerical simulations. The stability analyses of the models showed that
wildebeests and zebras population growth approached their respective carrying capacities, and
the absence of one prey species does not affect the existence of the other. The advection and
diffusion parameters in the model produce Turing instabilities. Furthermore, the results show
that both prey species are strongly affected by drought and predation pressure, especially from
lions. Therefore, advection and diffusion of wildebeests and zebras are motivated by the search
for better forage availability and avoidance of predators, while the predator's movement is
motivated by capturing prey
Mathematical modeling of covid-19 transmission dynamics between healthcare workers and community
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Mathematical and Computer Sciences and Engineering of the Nelson Mandela African Institution of Science and TechnologyCOVID-19 pandemic has posed an unprecedented threat to global public health. Health profes sionals caring for COVID-19 patients face insomnia, mental stress, physical exhaustion, stigma,
the pain of losing patients and colleagues. Many of them acquired SARS-CoV-2 and some died.
Protection of this workforce is of paramount importance to ensure optimal care to patients. Thus,
this study contributes to the subject by formulating a deterministic mathematical model SW E
IsIaHR (Susceptible - Healthcare workers - Exposed - Symptomatic - Asymptomatic - Hospi talized - Recovered) that combines both healthcare workers (as an independent compartment)
and community and focuses on the protection of the healthcare workforce against SARS-COV-2.
Benefiting the next generation matrix method, the basic reproduction number (R0) was computed.
Routh-Hurwitz criterion and stable Metzler matrix theory revealed that disease-free equilibrium
point is locally and globally asymptotically stable whenever R0 1.
Further, the dynamics behavior of R0 was explored when varying the use personal protective
equipment (ξ) and physical distancing (θ). In the absence of protective measures (ξ and θ), the
value of R0 was 6.7125 which implies the expansion of the disease. When θ and ξ were introduced
in the model, R0 was 0.6713, indicating the decrease of the disease in the community. Numer ical solutions were simulated by using Runge-Kutta fourth-order method. The numerical results
illustrated mathematically that protection of health care workers can be achieved through effec tive use of personal protective equipment and minimization of transmission of COVID-19 in the
community
FakeAP Detector: An Android-Based Client-Side Application for Detecting Wi-Fi Hotspot Spoofing
Get PDFThis research article published by IEEE Access, 2022Network spoofing is becoming a common attack in wireless networks. The trend is going
high due to an increase in Internet users. Similarly, there is a rapid growth of numbers in mobile devices
in the working environments and on most official occasions. The trends pose a huge threat to users since
they become the prime target of attackers. More unfortunately, mobile devices have weak security measures
due to their limited computational powers. Current approaches to detect spoofing attacks focus on personal
computers and rely on the network hosts’ capacity, leaving guest users with mobile devices at risk. Some
approaches on Android-based devices demand root privilege, which is highly discouraged. This paper
presents an Android-based client-side solution to detect the presence of fake access points in a perimeter
using details collected from probe responses. Our approach considers the difference in security information
and signal level of an access point (AP). We present the detection in three networks, (i) open networks,
(ii) closed networks and (iii) networks with captive portals. As a departure from existing works, our solution
does not require root access for detection, and it is developed for portability and better performance.
Experimental results show that our approach can detect fake access points with an accuracy of 99% and
99.7% at an average of 24.64 and 7.78 milliseconds in open and closed networks, respectively
Remediation of Soils Contaminated by Fluoride Using a Fermentation Product of Seaweed (Eucheuma cottonii)
Get PDFThis research article was published by Hindawi in 2022is study investigated the e cacy of fermented seaweed (Eucheuma cottonii) on the remediation of uoride-contaminated soil.
e soil was amended with either 1.25, 3.0, or 5.0% (w/w) fermented seaweed (FSW), parallel with the controls (0%). e
amendment improved the physicochemical properties of the soil particularly pH regulated from strong alkaline (9.3) to neutral
(7.0) which is essential for germination, crop growth, and yield. e amount of water soluble- uoride (Ws-F) dropped from
81.7 ± 3.1 mg/kg to 42.7 ± 2.4, 33.7 ± 1.2, 19.6 ± 0.9, and 12 ± 1.3 mg/kg following 0, 1.25, 3, and 5% amendment dosage, re spectively. Most of the Ws-F was converted into exchangeable uoride (Ex-F) and to uoride-bound to iron and manganese (Fe/
Mn-F). Furthermore, the amendment also enhanced microbial mass and diversity in the soil. e FSW contains organic acids
which participate in ionic bonding with the multivalent cations in the soil. e formed compound participates in ion exchange
with clay or with anionic adsorption to positively charged clay sites at the edges. is interaction is further essential for enhancing
the uoride holding capacity of the soil. e use of seaweed reduced the bioavailability of uoride in the agricultural soils and had
positive e ects on promoting soil fertility. However, further studies to observe its e ects on crop performance is of signi cance
Antifungal Activities of Some Medicinal Plants Against Colletotrichum lindemuthianum, the Causal Pathogen of Bean Anthracnose, and their Effect on Seed Germination and Seedling Performance
Get PDFThis research article was published by the Centre for Advancement of Applied Sciences in Volume : 24, Issue : 4, 2022This study evaluated the in vitro potency of Plectranthus barbatus, Vernonia amygdalina, Conyza bonariensis, Leonotis nepetifolia, and Lantana camara extracts against Colletotrichum lindemuthianum, the causal pathogen of anthracnose in common bean (Phaseolus vulgaris), as well as assessed their effect on seed germination and seedling performance under greenhouse conditions. In vitro assessment of antifungal activities of extracts was carried out using the poisoned food technique. Ethyl acetate extract of C. bonariensis was found most effective against the pathogen and completely inhibited its growth at 5.0, 2.5, and 1.25 mg mL-1 while it showed 91.2% inhibition at 0.5 mg mL-1 level. This was followed by P. barbatus and L. nepetifolia which completely inhibited the growth at 5.0 and 2.5 mg mL-1 level. Methanolic extracts were also effective with highest inhibition observed for L. camara (85.1%) at 5.0 mg mL-1, followed by P. barbatus (84.7%) and L. nepetifolia (83.1%) at the same concentration. Similarly, the aqueous extracts showed remarkable inhibition at the highest concentrations tested. Aqueous extracts of L. nepetifolia, V. amygdalina, and C. bonariensis inflicted maximum inhibition at 5.0 mg mL-1 (75.0, 74.7, and 73.3%, respectively). Extracts had no adverse effect on seed germination and seedling performance, but the test fungicide reduced seed germination significantly (p < 0.001). Easy accessibility of the studied medicinal plants and their potential in managing bean anthracnose provides an opportunity to use such plant extracts as seed dressers to manage bean anthracnose in smallholder farmers in Tanzania
The effect of dietary sesame oil and ginger oil as antioxidants in the adult rat dorsal root ganglia after peripheral nerve crush injury
No full textThis research article was published by Taylor & Francis online in 2022Aim: The purpose of this study was to investigate the effect of dietary sesame oil and ginger
oil supplements on the dorsal root ganglia following a sciatic nerve crush model in male Wistar
albino rats.
Materials and methods: Crush injury models have been done by means of graded forceps (50
Newton). The animals were given a daily sesame oil (4ml/kg/day) and ginger oil (400mg/kg/
day) via oral gavage for a period of 28days. Dorsal root ganglia from the L5 levels were harvested.
Processing of tissues was done for electron microscopy and light microscopy. Immunohistochemical
staining with active caspase-3 antibody and qualitative ultrastructural analyses of tissues were
made by a light and a transmission electron microscope, respectively.
Results: The results showed that crush injury leads to remarkable ultrastructural changes in
sensory neurons, such as swollen mitochondria, disruption of cristae structure, glial cell
proliferation and, consequently, phagocytosis of the damaged neuron. These ultrastructural
changes were less evident in the treated groups, and both natural compounds reduced the
expression of activated caspase-3, which may also affect ultrastructural changes.
Conclusion: The application of the natural products sesame oil and ginger oil may represent a
supportive approach to the protection of sensory neurons against the destructive effects of
peripheral nerve crush injur
Effects of selected management practices of gutenbergia cordifolia on insect flower visitation at Mwiba area, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirement for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyWhile only few studies have presented the effect of invasive plant species on insect visitors, even
less is documented about how management practices against invasive plants may impact plant pollinator networks. The study assessed how natural versus chemical-based management practices
against the native invasive plant Gutenbergia cordifolia affected insect flower visitation in Mwiba
area by comparing the number of insect visitors, insect species diversity and richness, the number
of flowers visited, flower abundance, and diversity across treatments of Desmodium uncinatum
crude leaves extract (DUL), the chemical Glyphosate (GLY), and none (Control; CON). After
treatments, DUL plots had about one-third higher numbers of insects visitors compared to CON
and GLY plots (F2,159 = 9.521, df = 2, p = 0.009), including higher species diversity and richness
of bee in DUL than in GLY and CON (F2,12 = 5.497, df = 2, p = 0.020; F2,12 = 21.810, df = 2, p <
0.001 respectively). Further, DUL plots had almost twice as many flowers visited compared to
CON and GLY plots (F2,159 = 21.595, df = 2, p < 0.001). Flower abundance was higher in DUL
plots compared to CON and GLY as was flower diversity (χ
2 = 7.460, df = 2, p = 0.024; F2,12 =
3.963, df = 2, p = 0.048, respectively). Generally, this study discovered that DUL treatment did
not disturb insect flower visitation while GLY strongly did; instead, DUL attracted more insect
flower visitors. It is hereby concluded that using the natural plant extract treatment is highly
preferable to the chemical management of invasive plant G. cordifolia
Assessing residue effects of tobacco nicotine on the yields, nutrient concentrations and nicotine uptake of a subsequent maize crop
Get PDFThis research article was published by Elsevier, 2022The residue effects of tobacco (Nicotiana tabacum L.) nicotine on the subsequent maize (Zea mays L.) crop
cultivated in soils differing in texture has rarely been studied for over a decade. The present study was conducted
on sandy soil of Tabora, and loamy sand soils of Urambo, and Sikonge sites in Tabora region of Tanzania, to
assess the residue effects of tobacco nicotine on latter performance of a maize crop. The experiment was laid out
in a complete randomized block design with three replications. During the first cropping season (2017–18), the
treatments were composed of one unfertilized cultivated plot of tobacco as a control and a fertilized cultivated
plot, where the seedlings of flue-cured tobacco variety K326 were transplanted. Two separate plots were kept
fallow for planting sole maize (DKC-8053) under fertilized and unfertilized conditions without any nicotine
residue during the succeeding second (2018–19) and third (2019–20) cropping seasons. Moreover, in the first
cropping season, in one fertilized tobacco plot, tobacco stalks after reaping leaves were incorporated in soil for
natural decomposition, while in the other fertilized tobacco plot, tobacco stalks were uprooted. In the second and
third cropping seasons, the residue nicotine was measured in soils and found to range from 0.25 to 0.86 mg kg− 1
in both unfertilized and fertilized tobacco plots. The residue nicotine ranged from 0.92 to 1.05 mg kg− 1 in
fertilized tobacco cultivated soils with tobacco stalks. Results showed that nicotine residue in soil decreased
maize grain yield by 0.08 t ha− 1
. The decrease of maize grain yield was also attributed to inadequate P and K
levels in soils planted with tobacco. Therefore, this study recommends the supplemental application of the
limiting P and K nutrients when planting maize after tobacco
Rule-Based Engine for Automatic Allocation of Smallholder Dairy Producers in Preidentified Production Clusters
Get PDFThis research article was published by Hindawi, 2022Smallholder dairy producers account for around half of all African livestock ventures; nevertheless, they face challenges in producing more milk due to an insufficient framework and infrastructure to maximize their output. Smallholder dairy producers in this scenario use a variety of tactics to boost milk output. However, the attempts need multiple heuristics, time, and financial investment. Furthermore, because of a lack of extension officers, smallholder dairy producers become trapped in failure cycles, unsuccessful attempts, and a diminished motivation to continue farming. Therefore, the interventions were more straightforward as smallholder dairy producers with comparable characteristics grouped. This research aimed to create a rule-based engine that automatically assigns smallholder dairy producers to predefined clusters. About 78 stakeholders were interviewed, including 69 smallholder dairy producers and 9 extension officers from Meru-Arusha, Tanzania. The 10 production features and 6 predefined clusters were adopted from the previous study. Therefore, a rule-based engine used the selected 10 production features. As a result, the rule-based engine automatically assigns the smallholder dairy producers to their respective clusters. Therefore, smallholder dairy producers share their farming skills and experience to increase milk output through these clusters. Furthermore, extension officers in the system provide timely assistance to smallholder dairy producers with farming concerns
Modeling the effects of temperature and heterogeneous biting exposure on chikungunya virus disease dynamics
Get PDFThis research article was published by Elsevier, 2022Within the last decades, chikungunya virus (CHIKV), a mosquito-borne arboviral disease transmitted by Aedes species mosquitoes has been a growing public health burden. Approximately 1.3 billion inhabitants in 94 countries are estimated to be at risk of chikungunya virus infection. Prior studies suggest that temperature and heterogeneous biting exposure are some of the key determinant factors in transmission dynamics of vector-borne diseases. In order to direct preparedness for future outbreaks, it is imperative to evaluate the effects of heterogeneous biting exposure and temperature variations on transmission dynamics of CHIKV. In this paper, a mathematical model that incorporates heterogeneous biting exposure and temperature effects has been developed and analyzed. The basic reproduction number, an important metric for infectious disease models has been determined. Data from literature has been used to calibrate the model and observed CHIKV data for Kadmat primary health centre, India (2 July to 7 September 2007) has been used to validate the model. Results from the study suggest that disease prevention strategies which are effective at stopping transmission of CHIKV more than 80% of the time, will be highly effective minimizing disease burden during outbreaks. The proposed model can be used to inform policy makers on effective ways of managing CHIKV during outbreaks