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Roles of Maasai Alalili Systems in Sustainable Conservation of Fodder Species of East African Rangelands
Full text linkThis research article was published by Rangeland Ecology & Management Volume 98, January 2025Alalili systems are among the indigenous rangeland management strategies that face pressures from unsustainable land use practices and impacts of climate change. We aimed to establish the vascular fodder plants' composition and abundance, compared with historical vegetation data to understand their evolution and trends to inform sustainable management of rangelands in northern Tanzania. The vegetation composition of the northern Tanzania rangelands surveyed before the 1980s was compared to empirical data from a vegetation survey of Alalili in 2022. A cross-sectional design using purposive and stratified random sampling techniques was applied during the field survey. The quadrat count method was used to estimate the composition and diversity of fodder taxa in Alalili systems. Secondary data from the northern Tanzania rangelands before the 1980s were collected through a systematic literature review. Key informant interviews, focused group discussions, and household surveys were used to gather information about the community's knowledge of historical quality changes in the rangelands. Our results indicate that, before the 1980s, the rangelands of northern Tanzania had relatively higher fodder species composition (127 woody and 119 herbaceous species) than the Alalili systems in 2022 (119 woody and 82 herbaceous species). Fodder species composition and diversity were relatively higher in communal than in private Alalili (t = 4.18, P < 0.001). At the same time, the species density was lower in communal than in private Alalili (t = -2.7272, P = 0.008). This work suggests that Alalili systems still hold substantial diverse fodder plants that most northern Tanzanian rangelands used to harbor before the 1980s. Therefore, they can be considered reservoirs of vital fodder species that can be used to restore degraded rangeland areas in northern Tanzania and elsewhere
Modeling salmonellosis transmission dynamics in humans and dairy cattle with optimal controls
No full textThis research article was published in the journal of Applied Mathematical Modelling, Volume 138, 2025In this paper, we develop a mathematical model to examine the transmission dynamics and control analysis of salmonellosis in humans and dairy cattle. The model considers three time-dependent controls (improving hygiene, vaccination, and organic acid disinfectants), human and dairy cattle populations, and Salmonella typhimurium bacteria in the environments and dairy products. The next generation matrix technique is applied to compute the effective reproduction number
that gauges the persistence and extinction of salmonellosis while adopting the proposed control interventions. The stability behavior of the equilibrium states is examined using the Lypunov function method based on the effective reproduction number
. The Latin hypercube sampling and the partial rank correlation coefficient methods are used to investigate the sensitivity and uncertainty of input parameters against model outputs. The results indicate that improving hygiene and vaccination can eliminate salmonellosis. Improving hygiene habits at a rate of at least 0.9 per day is recommended to eliminate salmonellosis. An efficacious vaccine that can immunize at least 85% of the vaccinated dairy cattle is also recommended to eradicate salmonellosis if it can be implemented to vaccinate susceptible dairy cattle at a rate of at least 0.45 per day for the first 30 days of the salmonellosis outbreak. The use of all three controls is recommended to eliminate salmonellosis quickly and at the lowest cost
Economic Viability of Micro-Irrigation Technologies in Smallholder Horticultural Farming: A Comparative Study with Traditional Furrow Irrigation in Northern Tanzania
No full textThis Research article was published by GAJEB on 21.03.2025This study investigated the economic viability of Micro Irrigation
Technologies (MITs) compared with traditional furrow irrigation in smallholder
horticultural farming in northern Tanzania. Using a quasi-experimental cross-
sectional design, data were collected from 540 farmers, divided into adopters
and nonadopters of MITs. Economic metrics, including net present value (NPV),
the benefit‒cost ratio (BCR), and the internal rate of return (IRR), were analysed
over a five-year investment horizon through statistical methods in SPSS and
Microsoft Excel. The results indicate that MITs, particularly drip and sprinkler
systems, increase the productivity and profitability of high-value crops such as
onions and tomatoes, yielding significantly higher NPVs than furrow irrigation
does. Despite their high initial costs, these technologies demonstrated long-term
economic benefits, including improved water efficiency and labour cost savings.
Regression analysis further revealed that both crop type and irrigation
technology significantly influence economic outcomes. Onions and tomatoes
under MIT presented the highest financial returns, whereas peppers under
furrow irrigation achieved better cost efficiency. This study underscores the
transformative potential of MITs in enhancing horticultural productivity and
sustainability in water-scarce regions. The study recommends targeted
interventions, including subsidies, financial incentives, training programs, and
policy support, to scale up the adoption of MITs
Association Between Aflatoxin Exposure and Haemoglobin, Zinc, and Vitamin A, C, and E Levels/Status: A Systematic Review
No full textThis research article was published by Nutrients, Volume 17, 2025Background: Aflatoxin, produced by Aspergillus flavus and Aspergillus parasiticus fungi, contaminates a broad range of crops such as maize, nuts, and cotton. Aflatoxin exposure causes growth failure, immune suppression, and liver cancer. While several systematic reviews have assessed the link between aflatoxin exposure and growth development in humans, there is a lack of reviews on the associations between aflatoxin exposure and micronutrient levels/status. This review addresses that gap by compiling studies on the association between aflatoxin exposure and micronutrient levels/status in humans. Methods: A comprehensive search of the SCOPUS, PUBMED, EMBASE, and Web of Science databases was conducted, focusing on studies published between 2003 and 2023. Only English-language studies using urine, blood, serum, or plasma biomarkers were included to assess the exposure and outcomes. The risk of bias in these studies was evaluated using the Academy of Nutrition and Dietetics Quality Criteria for human studies. Results: Ten observational studies were included in the systematic review, which collectively reported the association between aflatoxin exposure and haemoglobin, zinc, and vitamin A, E, and C levels. This review suggests that aflatoxin exposure is associated with micronutrient deficiencies, such as anaemia (low haemoglobin levels (<11 g/dL)) in pregnant women and vitamin A deficiency in adults and children. Conclusions: This review highlights the link between aflatoxin exposure and micronutrient deficiencies, emphasizing the need for aflatoxin mitigation within micronutrient interventions. Future studies should focus on longitudinal and interventional research to establish causal relationships and assess the effectiveness of mitigation strategies. Additionally, further research is needed to explore the interaction between aflatoxin exposure and other potential confounding factors such as dietary patterns, socioeconomic status, and genetic predisposition
African wild dog population status in the Selous-Nyerere landscape, southern Tanzania: Insights from camera trap surveys
No full textThis research article was published by Global Ecology and Conservation , Volume 60, August 2025Despite being one of the world’s most endangered carnivore, there is a deficiency of recent information on the status of African wild dog (Lycaon pictus) in some of the few landscapes where viable populations are thought to still occur. One example is the Selous-Nyerere landscape in southern Tanzania, a critical stronghold for the species that has not been studied since the 1990s. We use data from seven camera trap surveys deployed over 4674 km2 in Selous Game Reserve (GR) and Nyerere National Park (NP) from 2020 to 2022 to provide an update on wild dog status in the landscape. We identified a total of 222 wild dogs, of which 38 % were male, 38 % were female, and 24 % were of unknown sex. We applied spatially explicit capture-recapture (SECR) modelling to the data from 2565 km2 of Selous GR to estimate an over-dispersion adjusted population density of 2.14 ± 0.45 adult and yearling wild dogs per 100 km2 (95 % confidence interval: 1.42 – 3.21). This study demonstrates the ways in which camera trap data can be used to improve our understanding of wild dog populations in data-limited settings, but also highlights some limitations of this data type for the species. Our findings suggest that the Selous-Niassa ecosystem is one of the most important remaining populations of wild dogs in Africa. Although this study did not directly investigate mortality, we recommend long-term monitoring and a number of conservation actions to tackle the species’ apparent threats in the landscape, and help secure this stronghold into the future
The effect of an intervention to reduce aflatoxin consumption from 6 to 18 mo of age on length-for-age z-scores in rural Tanzania: a cluster-randomized trial
No full textThis research article was published by The American Journal of Clinical Nutrition Volume 121, February 2025Background
Linear growth faltering continues to negatively affect children in low- and middle-income countries and is associated with poor cognitive, developmental, and educational outcomes. Laboratory and observational data suggest that aflatoxin (AF) is a contributor to stunting.
Objective
The Mycotoxin Mitigation Trial was a cluster-randomized, community-based 2-group trial conducted in Kongwa District, Tanzania, between 2018 and 2020. The trial assessed whether a 12-mo intervention to reduce AF consumption increased length-for-age z-scores (LAZ) at 18 mo.
Methods
Low-AF maize and groundnut flours were provided to the intervention group each month; skin lotion was distributed to the control group monthly. Infant and young child feeding education was delivered equally in 52 health facilities (clusters). Anthropometry and the AF blood biomarker serum AF-albumin (AF-alb) were assessed at 6, 12, and 18 mo of age. Outcomes were analyzed as intention-to-treat and per-protocol using linear mixed-effects models.
Results
Two thousand eight hundred forty-two maternal–infant dyads were recruited into the study. The intervention did not create a contrast in AF-alb. At 18 mo, 36% (n = 186/520) of infants had detectable levels of AF-alb compared with 54% (n = 195/364) at baseline, with no difference between groups. Mean LAZ in the intervention group at 18 mo was −1.83 (n = 1231, 95% CI: −1.93, −1.73) compared to −1.90 (n = 1287, 95% CI: −1.99, −1.82) in the control group (P = 0.28).
Conclusions
An intervention to reduce AF exposure did not alter AF-alb nor anthropometric measures between treatment groups. Drought and agricultural data indicated less favorable conditions for toxin production, resulting in low levels of exposure in both trial arms. Annual, seasonal, and geographic heterogeneity of AF contamination make it difficult to study in an ethically designed trial. Our formative research and early trial data indicate that stunting and intermittent AF exposure continue to be a problem in this region. However, the low-AF exposure levels during the trial led to inconclusive results
Integrated rapid risk assessment for dengue fever in settings with limited diagnostic capacity and uncertain exposure: Development of a methodological framework for Tanzania
No full textThis research article was published by PLOS Negleted Tropical Diseases Volume 19,2025Background
Dengue fever is one of the world’s most important re-emerging but neglected infectious diseases. We aimed to develop and evaluate an integrated risk assessment framework to enhance early detection and risk assessment of potential dengue outbreaks in settings with limited routine surveillance and diagnostic capacity.
Methods
Our risk assessment framework utilizes the combination of various methodological components: We first focused on (I) identifying relevant clinical signals based on a case definition for suspected dengue, (II) refining the signal for potential dengue diagnosis using contextual data, and (III) determining the public health risk associated with a verified dengue signal across various hazard, exposure, and contextual indicators. We then evaluated our framework using (i) historical clinical signals with syndromic and laboratory-confirmed disease information derived from WHO’s Epidemic Intelligence from Open Sources (EIOS) technology using decision tree analyses, and (ii) historical dengue outbreak data from Tanzania at the regional level from 2019 (6,795 confirmed cases) using negative binomial regression analyses adjusted for month and region. Finally, we evaluated a test signal across all steps of our integrated framework to demonstrate the implementation of our multi-method approach.
Results
The result of the suspected case refinement algorithm for clinically defined syndromic cases was consistent with the laboratory-confirmed diagnosis (dengue yes or no). Regression between confirmed dengue fever cases in 2019 as the dependent variable and a site-specific public health risk score as the independent variable showed strong evidence of an increase in dengue fever cases with higher site-specific risk (rate ratio = 2.51 (95% CI = [1.76, 3.58])).
Conclusions
The framework can be used to rapidly determine the public health risk of dengue outbreaks, which is useful for planning and prioritizing interventions or for epidemic preparedness. It further allows for flexibility in its adaptation to target diseases and geographical contexts
A framework for managing infectious diseases in rural areas in low-and middle-income countries in the face of climate change—East Africa as a case study
No full textThis research article was published by PLOS Global Public Health, 2025Climate change is having unprecedented impacts on human health, including increasing infectious disease risk. Despite this, health systems across the world are currently not prepared for novel disease scenarios anticipated with climate change. While the need for health systems to develop climate change adaptation strategies has been stressed in the past, there is no clear consensus on how this can be achieved, especially in rural areas in low- and middle-income countries that experience high disease burdens and climate change impacts simultaneously. Here, we highlight the need to put health systems in the context of climate change and demonstrate how this can be achieved by taking into account all aspects of infectious disease risk (i.e., pathogen hazards, and exposure and vulnerability to these pathogen hazards). The framework focuses on rural communities in East Africa since communities in this region experience climate change impacts, present specific vulnerabilities and exposure to climate-related hazards, and have regular exposure to a high burden of infectious diseases. Implementing the outlined approach can help make health systems climate adapted and avoid slowing momentum towards achieving global health grand challenge targets
Effect of fire timing on the regeneration capacity of Helichrysum species in Tanzania
No full textThis research article was published by ecological solutions and evidence, 20251. Shrub encroachment poses a significant challenge in many grassland ecosystems,
particularly where disturbances such as heavy livestock grazing and uncontrolled
fires are prevalent. Fire is frequently employed as a management tool to mitigate
shrub encroachment and preserve native vegetation, as it influences both
resprouting and seed germination. However, few studies have examined the
effects of fire timing on resprouting and seed germination both in the field and
ex situ.
2. We investigated the resprouting ability of Helichrysum shrubs after being
completely, partially or not at all burned. In addition, we collected soil seed bank
samples from each early burned, late burned and unburned area at depths of 0–2,
2–4 and 4–6 cm to assess plant species recruitment via seedlings. The data were
analysed using a generalized linear regression model with a Gaussian link function.
3. We found significant differences in the number of resprouts and seedling
abundance across early burned, late burned and unburned sites. Resprouting
of both partially burned and completely burned shrubs was more abundant
compared to unburned shrubs. The surface soil in unburned sites contained a
greater abundance of Helichrysum seedlings compared to that of burned sites,
suggesting that fire negatively affects seed germination, particularly in the upper
soil layers. Overall seedling recruitment was lower in early and late burned areas,
whereas resprouting was higher in areas burned later in the season.
4. Practical implication. The findings highlight the significance of fire timing in
grassland management. We advocate for the implementation of planned
early burning to mitigate shrub encroachment, promote biodiversity and save
ecologically sensitive grasslands
Simulation and Experimental Performance Analysis of Portable Locally-Made Solar-Powered Cooler for Vaccine Storage
No full textThis research article was published by Advances in Science and Technology Volume 160, 2025Poor storage conditions, particularly exposure to extreme temperatures, can significantly compromise vaccine efficacy, making them ineffective or harmful. This highlights the urgent need for adequate storage infrastructure and monitoring systems, especially in remote areas with limited healthcare resources. This study evaluates the performance of a locally-made solar-powered cooler designed for vaccine storage in such environments. A digital AKO thermostat was integrated to control the compressor according to specified temperature limits, alongside a data logger for continuous temperature monitoring and a fluke device for DC and voltage measurements. The experimental results, validated against existing literature, were reliable and accurate. Key findings reveal that the cooler can reduce temperature to -14.9°C within 180 minutes, surpassing the performance of previous models that attained a temperature of -10°C after 144 minutes. The optimal insulation thickness for maintaining a cooling temperature of -15°C was determined to be 0.07 m using polyurethane insulation material, compared to 0.129 m with Feather Fiber, reflecting a 45.7% increase in efficiency at an ambient temperature of 42°C. Similar results were observed at an ambient temperature of 32°C. Modeling outcomes provided valuable guidance for the experimental design and comparative analysis