2647 research outputs found
Sort by
Ecological Consequences of Antibiotics Pollution in Sub-Saharan Africa: Understanding Sources, Pathways, and Potential Implications
Full text linkThis research article was published by Emerging Contaminants, 2025In Sub-Saharan Africa (SSA), the increasing use of antibiotics in human and veterinary medicine, combined with inadequate waste and water management systems, has intensified the problem of antibiotic pollution. Untreated or partially treated wastewater from industries, agricultural runoff, residential areas, and healthcare facilities is frequently discharged into the environment, often used for irrigation, contributing to antibiotic accumulation, the spread of resistance genes, and the rise of antibiotic resistance, posing serious threats to public health and environmental sustainability. The region's climatic conditions favour the survival and proliferation of microbial communities, including pathogens. Additionally, the high prevalence of infectious diseases such as HIV/AIDS, tuberculosis, and malaria, which often necessitate antibiotic use, further amplifies the issue. Systemic challenges, including poor waste management, inadequate or absent wastewater treatment infrastructure, weak regulatory enforcement, and the over-the-counter sale of antibiotics, exacerbate the crisis. Limited healthcare access often results in self-medication and improper antibiotic use, accelerating resistance spread. Evidence shows antibiotics in surface water, groundwater, effluents, food crops, environmental samples, and aquatic organisms, indicating their potential circulation through the food chain. However, a lack of comprehensive data on antibiotic pollution and its impacts on aquatic ecosystems in SSA hampers a thorough understanding of its scope and long-term effects. Addressing this crisis requires identifying contamination hotspots, evaluating ecological impacts, and establishing robust, region-specific regulatory frameworks to ensure environmental and public health safet
Dynamical modeling of Salmonellosis in humans and dairy cattle with temperature and pH effects
No full textThis research article was published in the journal of Research in Veterinary Science, Volume 184, 2025Approximately 20 million cases and 0.15 million human fatalities worldwide each year are caused by Salmonellosis. A mechanistic compartmental model based on ordinary differential equations is proposed to evaluate the effects of temperature and pH on the transmission dynamics of Salmonellosis. The transmission potential of the disease in areas with temperature and pH stresses is examined. The next-generation matrix method is applied to compute the temperature-pH-dependent reproduction number
. The dynamical regimes of the system are examined using Lyapunov stability theory and backward bifurcation analysis. The uncertainty and global sensitivity analysis are examined using the Latin Hypercube Sampling (LHS) and Partial Rank Correlation Coefficient (PRCC) methods. The numerical simulations of the proposed model under favorable and unfavorable temperatures are performed with a
confidence interval (CI) for the reliability assessment of the model parameters. The analysis shows that the ingestion rates of Salmonella enterica subsp. enterica serovar Typhimurium bacteria in humans and dairy cattle, human-to-human transmission rate, cattle-to-cattle transmission rate, human shedding rate, dairy cattle shedding rate, and the rate of producing contaminated dairy products are directly proportional to the number of infected humans and infected dairy cattle. The temperature ranges of
and
and pHs greater than 3.8 have a significant effect on the dynamics of Salmonellosis. In order to eliminate Salmonellosis, the study recommends treating natural water bodies using the recommended chemical disinfectants during summer seasons and in areas with temperature ranges of
, cooking food at the hottest temperatures, and storing food at the lowest temperatures for all pHs
Sub-acute Toxicity Effects of the Methanolic Extract from Searsia longipes on the Hematological, Biochemical and Histopathological Parameters of Wilstar Albino Rats
No full textThis research article was published by Natural Product Communications, Volume 20, 2025Background: Searsia longipes is a medicinal plant used in Tanzania and other parts of Africa in the management of various diseases. Despite its wide utilization as folk medicine, there is a paucity of safety information about the extract from this plant. Objectives: The present study aimed at investigating the sub-acute toxicity of the methanolic extract from this plant. Methods: The crude extract from the stem bark of S. longipes was extracted by using methanol, after which the assessment of its toxicity was done on Wilstar albino rats. Parameters including haematological, biochemical, histopathological, as well as organ and animal weight were examined to unveil the toxic effect of the plant extract. Results: The plant extract did not induce significant changes to most hematological parameters except for white blood cells, which demonstrated a dose-dependent increase. Notably, thrombocytes showed an increase that was directly proportional to the increase in the extract dose, although not significant. The biochemical parameters did not show significant increase, whereas the histopathological analysis demonstrated mild morphological changes to the liver and kidney at the highest dose used. There were no significant variations in the organ weights; meanwhile, the body weights in treatment groups expressed time-dependent increases, which is similar to that of the control group. Conclusion: This study reports the sub-acute toxicity profile of the extract from S. longipes for the first time. This information is crucial as it not only fills a significant gap in our knowledge but also paves the way for further exploration of this plant as a potential source of diverse therapeutic agents
Modelling and analysis of hydraulic transients in water pipelines using physics-informed neural network
No full textThis research article was published in the Scientific African, Volume 28, 2025Hydraulic transients remain a challenge in fluid flow systems, spanning basic pipelines to
complex networks. While advances in transient analysis methods have been made, most
approaches require full boundary condition data or rely on computationally intensive mesh
based techniques. In response to these limitations, PINNs have emerged as a promising
alternative for predicting pressure and flow rate transients in pipeline systems without requiring
complete knowledge of boundary conditions. The PINN model was trained both with and
without initial and boundary condition data, achieving results that matched the Method of
Characteristics reference with remarkable accuracy. Notably, the model effectively captured
pressure and flow rate traces, even when tested on data from unmonitored locations. This
demonstrate the robustness of PINN in addressing incomplete data challenges, enhance mesh
free computation, and optimising transient analysis. These findings highlight PINN as a powerful
tool for improving field data accuracy and computational efficiency in hydraulic systems, paving
the way for their broader application in fluid flow networks
Kinetics and energetics of biodiesel oxidation stability: The impact of Uapaca kirkiana-derived natural antioxidants
No full textThis research article was published by Biofuels, Bioproducts and Biorefining Volume19, 2025Despite considerable progress in understanding biodiesel autoxidation inhibition, the kinetics and energetics of the inhibition reactions involving natural antioxidants remain underexplored. Most existing research on natural antioxidants has focused on enhancing oxidation stability and other fuel properties. This study aimed to investigate the oxidative stability of croton biodiesel (CBD) and assess the kinetics and energetics of natural antioxidants derived from the roots, pulp, and fruit peels of the Uapaca kirkiana plant. The oxidation stability of biodiesel samples was assessed using the OXITEST method at temperatures of 90, 100, 110, and 120 °C. These tests enabled the calculation of kinetic parameters such as reaction rates and activation energies, crucial for understanding the inhibition role of antioxidants during oxidative degradation. Activation energy for antioxidant consumption, determined using the Arrhenius equation, was found to be 81.39 kJ mol−1 for fruit peel extracts, 77.73 kJ mol−1 for pulp extracts, and 63.85 kJ mol−1 for root bark extracts. The higher activation energy for fruit peel extracts suggests that they are more effective at preventing oxidation, especially under high-temperature conditions. Enthalpy, entropy, and Gibbs free energy parameters were calculated using the Eyring equation, indicating a nonspontaneous endothermic process for the antioxidant samples. The study found an inverse relationship between antioxidant concentration and rate constants, demonstrating the antioxidants' effectiveness in slowing down the oxidation process. These kinetics and energetics analyses provide detailed insights into how antioxidants function, facilitating the optimization, selection, and validation of their efficiency in stabilizing biodiesel
Factors Contributing to Retention in Care and Treatment Adherence Among People Living With HIV Returning to Care in South-Eastern Tanzania: A Qualitative Study
No full textThis research article was published in the journal of HIV/AIDS - Research and Palliative Care
Volume 17, 2025Background
People living with HIV (PLHIV) with good adherence to antiretroviral therapy (ART) achieve good health outcomes. However, treatment interruptions remain a major challenge, particularly in rural Africa. This study explored factors related to dropout, return, retention in care, and treatment adherence among PLHIV returning to care after missing clinical visits.
Methods
We conducted an exploratory study using a phenomenological approach in rural South-eastern Tanzania, from July to October 2023. In-depth interviews (IDIs) were conducted with 21 PLHIV who resumed care after missing visits for three months or more from the last scheduled appointment and who were taking ART less than 60 days within the last three months, and their 13 treatment supporters. Interviews were conducted at St. Francis Regional Referral Hospital and Kibaoni Health Center.Five focus group discussions (FGDs) were conducted with 6–8 healthcare workers from Kibaoni, Mang’ula, Mkamba, Mgeta Health Center, and St. Francis Hospital. Data were analyzed by thematic analysis, with NVivo 12 software.
Results
The median age of the 21 PLHIV was 40 years (range 21 to 63); 10 (47.6%) were females. Reasons for dropping out of care reported included fear of disclosure, complacency with improved health, denial of HIV status, work-related absence, and religious beliefs. Reasons for returning included health deterioration, completion of work obligations causing care interruption, family support, and clinic follow up. Factors promoting retention and adherence were improved health through ART, trust in healthcare services, counseling, health education, clinic follow-up, longer drug refill periods, and family support.
Conclusion
Our study highlights persisting stigmatization contributing to dropping from care, with strong family and social support improving adherence and clinic attendance. Future interventions should focus on these factors to enhance retention of lifelong treatment adherence. Working obligations remain a challenge, that could be addressed by facilitated access to remote drug pickup
AMMI and GGE biplot analysis of maize genotypes for seed yield across different maize growing location in Tanzania
No full textThis research article was published by Cogent Food & Agriculture , Volume 11, 2025Twenty maize genotypes including breeding lines along with improved local released varieties were assessed for grain yield and yield component stability under three different maize growing agro-ecological zones from January to August 2023. A randomized complete block design (RCBD) with three replication was employed. additive main effects and multiplicative interaction (AMMI) and genotype-by-environment interaction (GGE) analysis was utilized to study the genotype and environment (GE) interactions. The combined analysis of variance showed a significant difference (p ≤ 0.001) in grain yield traits between maize genotypes, environments, interactions and IPC components. The average mean grain yield ranged from 3244 to 5103 kg/ha with a grand mean of 4111 kg/ha The maximum and minimum grain yield was 12325.93 kg/ha (G4) and 1159.68 kg/ha (G9) respectively. The biplot results showed genotype G20, G3, G1, G17 and G15 demonstrated consistently high stable grain yield performance. Genotypes G14, G19 and G4 had high yields, but were unstable as they were far from the IPC1 zero line. Multi-trait stability value indicated that the best genotypes in performance for all traits were G5, G17 and G19. AMMI analysis revealed that the environment at Kibaigwa and NM-AIST was the most ideal environment for seed yield traits. Based on the consistently high and stable grain yield performance, along with other superior grain qualities and plant characteristics, genotypes G5 and G17 were selected and recommended to be advanced and released as new commercial maize varieties in Tanzania for wider cultivation by farmers together with G19, a commercially released variety in Tanzania
Pesticidal and Medicinal Value of Turmeric and Ginger in Tanzania and Their Antifungal Activity against Phytopathogens
Full text linkThis research article was published in the Journal of Biosciences and Medicines, Volume 13(2), 2025Use of synthetic pesticides to manage crop pests has had a toll on human
health, environmental safety and farmer’s income creating a need for alterna
tive crop protection strategies. Botanical pesticides have been reported to be
effective in managing crop pests, and a number of them have been formulated
and commercialized. This study was conducted in North-Eastern Tanzania to
establish the pesticidal and medicinal value of turmeric (Curcuma longa) and
ginger (Zingiber officinale). Purposive sampling was adopted to select and in
terview 167 respondents drawn from farmers, traders, pharmaceutical shops,
agro-shop operators and consumers of turmeric and ginger. Ginger and tur
meric rhizomes were also collected for extraction, antifungal assay and bio
chemical analysis. Results showed that majority of the respondents were aware
of the medicinal value of ginger and turmeric, with 59.5% having used the
plants to treat respiratory related infections and healing skin surface and in
ternal wounds. About 14% of farmers were aware of and had used aqueous
botanical preparations from neem, moringa and Tephrosia to manage insect
pests. Only 2.7% of farmers had used ginger powder as a protective insecticide
on stored grains. Ginger and turmeric rhizome extracts showed high antifun
gal activity against Pythium (83% - 95%), Fusarium oxysporum f. sp. lycoper
sici (34% - 52%) and Alternaria solani (38% - 53%). A GC-MS analysis of gin
ger and turmeric extracts showed presence of α-zingiberene, β-sesquiphellan
drene, α-farnesene, ar-curcumene, α-copaene, ar-tumerone and curlone. This
study recommends that ginger and turmeric extracts be considered for devel
opment of a botanical pesticide and especially for management of damping off
diseases
N-acetylcysteine modulates markers of oxidation, inflammation and infection in tuberculosis
Full text linkThis research article was published by Journal, 2025Background
Half the global tuberculosis health burden is due to post-tuberculosis lung disease. Host-directed therapies have been proposed to reduce this burden. N-acetylcysteine (NAC) provides the conditionally essential amino acid cysteine required for synthesis of glutathione, an antioxidant thiol. We recently reported clinical outcomes of a trial of adjunctive NAC in patients with pulmonary tuberculosis, finding that NAC improved the secondary endpoint of recovery of lung function. Here we report the effects of NAC on biomarkers of oxidation, inflammation, and infection in that trial.
Methods
140 adults with moderate or far-advanced pulmonary tuberculosis were randomly assigned to standard tuberculosis treatment with or without NAC 1200 mg twice daily for months 1-4. Sputum and blood samples were obtained at specified intervals to measure total glutathione, MTB-induced cytokines, haemoglobin, whole blood mycobactericidal activity (WBA), and sputum MTB burden.
Results
NAC treatment rapidly increased total glutathione (P<.0001), but levels did not reach those of healthy volunteers (P<.001). NAC reduced MTB-induced TNF-α (P =.011) without affecting IL-10, and accelerated the recovery of hemoglobin in participants with low values on entry. NAC did not affect killing in ex vivo whole blood culture but did slow the clearance of MTB from sputum (P=0.003).
Conclusion
Adjunctive NAC showed antioxidant and anti-inflammatory effects consistent with the amelioration of immunopathology seen in preclinical models. Two biomarkers of antimicrobial activity showed discordant results; neither demonstrated the enhanced antimicrobial effects seen preclinically. The reduction of oxidative stress and inflammation by NAC may explain its effects on the recovery of lung function post-TB
Radioactivity distribution in soil, rock and tailings at the Geita Gold Mine in Tanzania
No full textThis research article was published in the Journal of Radiation Research and Applied Sciences, Volume 18, Issue 2, 2025This study evaluated the activity concentrations of natural radionuclides in soil, waste rocks and tailings from the
Geita gold mining site in Tanzania using high-resolution gamma spectroscopy. A total of 41 samples: 31 soil, 5
waste rock, and 5 tailing samples were collected around the mine to assess their radiological hazards. The
average activity concentrations in soil were 54, 45 and 279 Bq kg-1 for 226Ra, 232Th and 40K. In contrast, tailings
exhibited higher activity concentrations of 70, 36 Bq kg-1 for 226Ra and 232Th, and significantly elevated levels of
877 Bq kg-1 for 40K, while waste rocks showed intermediate values, with 66, 73 and 660 Bq kg-1 for 226Ra, 232Th
and 40K respectively. Radiological hazard indices were calculated to quantify potential risks. In soil, the radium
equivalent activity (Raeq) averaged 139 Bq kg-1, the annual effective dose equivalent (AEDE) was 78 μSv y-1, the
annual gonadal dose equivalent (AGDE) reached 430 μSv y-1, and the excess lifetime cancer risk (ELCR) was 0.27
×10-1. Tailings showed a Raeq of 189 Bq kg-1, AEDE of 111 μSv y-1, AGDE of 678 μSv y-1, and ELCR of 0.39 ×10-
1, while waste rocks exhibited a Raeq of 200 Bq kg-1, AEDE of 108 μSv y-1, AGDE of 642 μSv y-1, and ELCR of 0.37
×10-3. Notably, the ELCR values for tailings and waste rocks exceeded the global average of 0.29 ×10-3,
rendering them unsuitable for use as building materials. The absorbed dose rates were 69 nGy h-1 for soil, 91 nGy
h-1 for tailings, and 88 nGy h-1 for waste rocks. One-way ANOVA revealed significant differences (p <0.05)
among the matrices. These findings underscore the need for targeted waste management and remediation
strategies to mitigate radiological health risks in the investigated mining area as well as other areas with similar
characteristics