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Susceptibility status of major malaria vectors to novaluron, an insect growth regulator South-Eastern Tanzania
Get PDFThis research was published Pan African Medical Journal, 2022Introduction: application of Insect Growth Regulator (IGR) such as pyriproxyfen has shown a promising result in controlling malaria transmitting mosquitoes through autodissemination technique. Novaluron that inhibits the chitin development at mosquito larval stage present a promising candidate IGR for rotation with pyriproxyfen to prevent a chance of resistance development. This study assessed the susceptibility of immature stages of Anopheles arabiensis, Anopheles gambiae and Anopheles funestus to novaluron.
Methods: susceptibility bioassays using technical grade novaluron (98% active ingredient) were performed inside the semi-field system using first instar larvae of Anopheles species. For each tested species, a total of 1500 larvae were used in the bioassay. Concentration range of 0.01 mg/l to 2 mg/l of novaluron were tested to establish Lethal Concentration (LC) sufficient to kills 50%, 90% and 99% of the exposed larvae by using log-dose response analysis.
Results: of the tested mosquitoes, Anopheles gambiae were highly susceptible to novaluron followed by An. arabiensis and then An. funestus. Lethal concentrations, LC50, LC90 and LC99 (95%CI) in mg/l for An. gambiae were 0.018, 0.332 and 2.001 respectively. For An. arabiensis were 0.026, 0.546 and 2.013; and for An. funestus were 0.032, 1.00 and 5.580. High larval mortality was recorded at high concentration (2mg/L), with 80% mortality within 3 days post exposure.
Conclusion: the study demonstrates the efficacy of novaluron in controlling Anopheles mosquito species at immature stages via larval mortality. These findings warrant further testing of novaluron for autodissemination by different vector species for its inclusion in rotation to prevent development of resistance
Importance of bio-pesticides formulations in managing insect pests of sesame in Africa
Get PDFThis research article published in the International Journal of Biosciences Vol. 20, No. 2, 2022Sesame is an important oil seed crop worldwide. However, its production faces a number of challenges such as infestation by insect pests and diseases, use of unimproved seeds by farmers and drought. Among all, insect pest is considered the most serious challenge affecting sesame production particularly in the Africa region. The common insect pests affecting sesame production in African smallholder farmers are Myzus persicae, Aphis gossypii, Bemisia tabaci, Antigastra catalaunalis, Orosius albicinctus, Tetranychus urticae, Spodoptera frugiperda and Alocypha bimaculata. These insect pests infest sesame at different stages of growth posing immense damage resulting into huge loss of yields. To control these insect pests most African smallholder farmers, use synthetic pesticides. However, most of those synthetic pesticides used cause environmental pollution and detriment effects to pollinators and natural enemies. Therefore, this paper reviews sesame insect pests and how they can be managed using bio-pesticides in African.
Herding strategies under shifting rainfall conditions: implications for rangeland conservation and pastoralist livelihoods
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirement for Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and TechnologyUnderstanding rainfall variability is of great importance in East Africa, where small-scale
farmers and pastoralists dominate. Factors such as fire, herbivory and soil conditions also
determine the spatial and temporal plant productivity, influencing livestock production and
wildlife sustainability. This study focused on assessing pastoralist herding strategies under
varying rainfall conditions as well as their implications to rangeland conservation and
pastoralist livelihood. I conducted 241 household interviews, collected information from 52
participants of Participatory Rural Appraisal (PRA), and used rainfall archived data from the
Ngorongoro Conservation Area Authority (NCAA) to assess pastoralists’ perception and actual
trends in rainfall, drought frequency, pasture availability, rangeland cover, and livestock
production. I established four exclusion plots of 1 m2
each within an area of 50 x 100 m at eight
sites to quantify the effect of grazing and to estimate grass productivity across season and
elevation. Single and multi-species groups of wild herbivores were recorded along road
transects in human-dominated landscapes of the Ngorongoro Conservation Area (NCA) in two
sampling periods (wet season: November–May and; dry season: June–October) in 2018-2019.
Most (71%) pastoralists were aware of general climate change, rainfall variability, and impacts
of extreme events on their livestock. The exclusion plots showed that aboveground primary
productivity and recovery from grazing was driven by both rainfall (F3, 4 = 19.165, p < 0.0001)
and elevation (F2, 3 = 11.319, p = 0.023). Wild herbivore group sizes (Mean ± SE) were larger
during the wet (7 ± 1 browsers, 19 ± 2 grazers and 19 ± 3 mixed feeders) than during the dry
season (3 ± 0 browsers, 13 ± 1 grazers and 13 ± 4 mixed feeders) and varied seasonally with
distance to Ngorongoro crater, streams, and human settlements. The study concludes that
rainfall variability and recurrent droughts are the major challenges to livestock production in
NCA. Moreover, increasing livestock population and high dependence on grazing resources
impact the potential of the rangeland to support livestock and wildlife. The study recommends
that wildlife coexistence is crucial for the protection status of this man-and-biosphere reserve,
however, the management should determine the optimal resource ratio and the level of stocking
densities the rangeland can support
Enhancement of customer retention of telecommunication companies in Tanzania through customer satisfaction
No full textThis research article was published by The Strategic Journal of Business & Change Management, Vol. 9, Iss. 3, August 8, 2022Little has been written on how customer satisfaction enhances customer retention in Tanzania’s
telecommunication companies. This study addressed that concern using six variables, namely rewards, tariffs,
customer care, branch physical appearance, network quality, and network coverage. Using probability and
non-probability sampling, 120 respondents to the questionnaire were selected. Results of descriptive and
binary regression analysis revealed customers were not satisfied due to low rewards (93.3%), high tariffs
(80.8%), unsatisfactory customer care (88.3%), uncomfortable branches (80%) and unstable network quality
(75%). Concerning predictor variables, the probability of the model giving the correct prediction ranges from
10% to 71%, where the higher deviances were tariffs, branch appearance, and network coverage (71%), and
rewards (57%). Chi square analysis, which compared the full model to a model with an intercept, found only
gender (under network quality and coverage), age, income, education, and time for reward to be statistically
significant (p<005). Furthermore, the logistic regression coefficient results showed that, for rewards,
predictor variables such as age, income, and time have positive and statistically significant effects. The study
concluded that rewards cause customer satisfaction and hence retention. However, if not well handled, high
tariffs, uncomfortable branches, poor network quality, and poor coverage lead to customer dissatisfaction
and low retention
Investigating effects of agricultural pesticides on susceptibility and fitness parameters of Malaria vectors in rural south eastern, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements of the Degree of Master of Science in Public Health Research of the Nelson Mandela African Institution of Science and TechnologyThe aim of this study was to investigate effects of agrochemicals on susceptibility and fitness of the
malaria vectors, An. gambiae s.l across farming areas in Tanzania. An exploratory mixed-methods
study was conducted to explore awareness on pesticide use among community members in four
villages (V1-V4) in south-eastern Tanzania. An. arabiensis larvae were collected from agricultural
fields in the same villages and their emergent adults examined for insecticide susceptibility, egg laying, and wing lengths (as proxy for body size). These tests were repeated using two groups of
laboratory-reared An. arabiensis, one of which was pre-exposed for 48hrs to sub-lethal aquatic doses
of agricultural pesticides found in the villages. Results revealed that farmers lacked awareness of the
linkages between public health and agriculture sectors but were interested in being more informed.
Agrochemical usage was reported as extensive in V1, V2 & V3 but minimal in V4. Similarly,
mosquitoes from V1-V3 but not V4 were resistant to pyrethroids, and either pirimiphos-methyl,
bendiocarb or both. Adding the synergist, piperonyl butoxide, restored potency of the pyrethroids.
Pre-exposure of laboratory-reared mosquitoes to pesticides during aquatic stages did not affect
insecticide susceptibility in emergent adults of the same filial generation. There was also no effect on
fecundity, except after pre-exposure to organophosphates, which were associated with fewer eggs and
smaller mosquitoes. In this study, susceptibility of mosquitoes to public health insecticides was lower
in villages reporting frequent use of pesticides compared to villages with little or no pesticide use. In
conclusion, safeguarding the potential of insecticide-based interventions requires improved
understanding of how agricultural pesticides influence important life-cycle processes and transmission
potential of mosquito vectors
Complexity of Epidemics Models: A Case-Study of Cholera in Tanzania
Get PDFThis research article was published by Springer Nature Switzerland AG., 2022Timely prediction of Cholera epidemics is essential for preventing and controlling the size of an outbreak. Over the past years, there have been great initiatives in the development of Cholera epidemic models using mathematical techniques, which are believed to be the most powerful tools in developing mechanistic understanding of epidemics. Despite the existence of these initiatives, the timely prediction of Cholera is still a great challenge. Recently, the World Health Organization reported that “the global burdens of waterborne epidemics from environmental factors are expected to increase over-time with an increase of epidemic size.” Due to these challenges, this paper reviewed existing Cholera mathematical models and observe that they have limitations/complexities, especially when working with many variables. The use of how machine learning (ML) can be used to overcome the limitations/complexities, such as lack of effective integration of environmental factors, such as weather are investigated. Hence, the study developed an ML reference model and its development procedures, which can be used to overcome the existing complexities. The results indicate at an average of 87% that the developed measures can integrate a large number of datasets, including environmental factors for the timely prediction of Cholera epidemics in Tanzania
Cultivation of Tomato under Dehydration and Salinity Stress: Unravelling the Physiology and Alternative Tolerance Options
Get PDFThis book chapter was published by IntechOpen in 2022Tomato is an important fruit vegetable in the world, as a nutritional source and an income option for a majority of resource constrained households. However, tomato supply in developing countries is often fluctuating, with high scarcity in both supply and quality during rainy season. Unlike many crops, cultivation of tomato is a challenging task during rainy season, with high pest and disease infestation. Hence, dry season is the most favorable period for tomato cultivation. However, inadequate water supply poses a yet another significant hurdle, as the crop requires high soil moisture for optimum growth. According to a landmark study by FAO, Tomato has a yield response factor of 1.05, which signifies that a smaller decline in water uptake results into a proportionally larger decline in yield. Moreover, over the years, there have been increasing reports of soil salinization, which imposes similar effects to drought stress through osmotic effects of Na+ in the soil solution and oxidative stress through excessive generation of reactive oxygen species. This chapter will dissect how tomato plants respond to these abiotic stress factors on physiological, anatomical, and molecular levels and suggest options to improve the crop’s productivity under these constraining environments
A review of the Development Trend of Personalized learning Technologies and its Applications
Get PDFThis research article was published by International Journal of Advances in Scientific Research and Engineering (ijasre) Volume 8, Issue 11, 2022Personalized learning tailors material and strategy to student requirements, interests, and goals in e-learning. These developments help educational institutions and other organizations to keep up with the fast pace of information technology, communications, and computing power. Studies show that self-adaptive learning and relevant learning information improve study efficiency.Compared to traditional teaching methods, the practice of online education is well in its infancy. On the other hand, the pedagogy and evaluation of students in online courses have a large gap that has to be filled, necessitating significant improvements in e-learning. We call this approach to education "personalized learning," which is a central focus of today's leading online education platforms. Several studies have been conducted on e-learning and personalized learning, but few investigated the development trend of personalized learning technologies and applications. Therefore this study examines the literature to close the gap and promote the development trend for personalized learning technologies and applications in higher education from 2010 to 2021 by analyzing related journal articles. The pivotal studies used inclusion criteria after a searchgenerated 372 complete research articles and reduced them to 146 publications based on their proposed learning domains and research themes. Through carefully reviewing current trends and successes in numerous aspects of personalized learning, this discussion analyzes prospective future research directions in the field of personalized learning
Taenia multiceps in Northern Tanzania: An Important but Preventable Disease Problem in Pastoral and Agropastoral Farming Systems
Get PDFThis research article was published in the Journal of Parasitologia Volume 2, Issue 3, 2022Coenurosis due to Taenia multiceps has emerged as a major concern to small ruminant-owning communities in northern Tanzania. Although a high incidence of disease has been reported, gaps still remain in our knowledge of the disease problem across different agro-ecological settings. The study aimed to determine the prevalence of coenurosis in small ruminants and taeniid infection in dogs and identify risk factors for infection. Questionnaire surveys, postmortem examination of small ruminants, and coproscopic examination of dog faeces were used to collect data on reported coenurosis cases and taeniid infections, respectively. The twelve-month period prevalence of coenurosis in small ruminants was 8.4% (95% CI 8.2–8.6). The prevalence of taeniid infection in dogs was 12.5% (95% CI 9.1–17.4). The village-level prevalence of coenurosis in sheep and goats was significantly correlated with taeniid infection prevalence in dogs (r = 0.51, p = 0.029). Multivariable analysis indicated that home slaughter was significantly associated with the livestock owner-reported neurological syndrome due to coenurosis in sheep and goats (OR = 13.3, 95% CI 4.2–42.0, p < 0.001) and the practice of offering discarded brains to dogs was significantly associated with taeniid infection prevalence in dogs (OR = 2.80, 95% CI 0.98–7.98, p = 0.05). Coenurosis is a major disease problem in livestock-keeping communities of northern Tanzania, but there is little awareness of transmission risks associated with home slaughter and dog feeding practices. There is a need for veterinary and animal health services to engage more actively with communities to increase awareness of the transmission cycle of T. multiceps and the preventive measures that can be taken to reduce the impact of disease in livestock-dependent communities