University of Namibia

Acrylamide (ACR) is an environmental and dietary contaminant widely known to induce imbalance in several biological systems, including oxidative stress, inflammation, and metabolic dysregulation. This study investigated the protective effects of gypenosides (GYP) against ACR-induced toxicity in human retinal pigment epithelial (RPE) cells and zebrafish embryos. RPE cells and zebrafish embryos were treated with ACR, or ACR + GYP; the levels of reactive oxygen species (ROS), antioxidative enzymes, proinflammatory cytokines, and lipids were measured using biochemical approaches. Our findings demonstrate that ACR exposure significantly elevated ROS production, increased lipid peroxidation, suppressed antioxidant defences, and upregulated pro-inflammatory cytokines in RPE cells. Additionally, ACR disrupted lipid metabolism, significantly increasing cellular cholesterol, triglyceride, and phospholipid levels while altering cholesterol metabolism gene expression. Co-treatment with GYP effectively mitigated ACR-induced oxidative stress by normalising ROS levels, restoring antioxidant enzyme activities, and upregulating antioxidant gene expression. GYP also attenuated the ACR-triggered inflammatory response, significantly downregulating the expression of proinflammatory cytokine genes. Furthermore, GYP normalised lipid profiles and modulated lipid-related gene expression disrupted by ACR exposure. Parallel zebrafish experiments corroborated these protective effects. ACR exposure led to delayed hatching, impaired cardiac function, increased ROS production, and neutral lipid accumulation. These adverse effects were markedly ameliorated by GYP co-treatment, which reduced oxidative stress, downregulated proinflammatory markers, and restored lipid homeostasis. The results highlighted that GYP, as a natural protective agent against ACR-induced cellular and metabolic toxicity in both in vitro and in vivo models, exhibited antioxidative, anti-inflammatory, and lipid-regulatory properties.

This study evaluated the effects of fly ash (F) and effective microorganisms (EM) on nutrient dynamics and heavy metal transformations during vermicomposting of camel manure (CM). Four treatments (CM, CM + F, CM + EM, and CM + F + EM) were arranged in a completely randomized design and monitored over 12 weeks. Significant (p < 0.05) treatment and time interactions were observed for pH, NH4-N, Mn, Pb, and Mo. The addition of EM resulted in a greater decline in pH compared to other treatments. After 12 weeks, Olsen P increased from 300.62 to 398.71 mg/kg in CM + EM, while NH4-N increased markedly from 22.74 to 86.62 mg/kg. In contrast, NO3/NO2-N declined in EM-amended treatments but increased in the control and CM + F. Trace metal concentrations generally increased due to mass reduction during vermicomposting yet remained within internationally acceptable limits. Germination index (GI) values varied significantly among crops and treatments, ranging from phytotoxic to non-phytotoxic responses. Although CM + EM produced superior nutrient enrichment, several vegetables exhibited GI values below 50%, indicating potential phytotoxicity for sensitive crops. In case of established crops for which nutrient supply outweighs early phytotoxic concerns, CM + EM represents the most agronomically beneficial option. Future studies should explore blending CM + EM and CM + F with stabilizing amendments such as biochar to optimize nutrient availability while minimizing salinity and phytotoxic risks.

ABSTRACT Sclerocarya birrea (marula) trees are important components of dry and semi‐dry African savanna environments due to their ecological and economical importance, including carbon storage. However, functional characteristics of these dioecious trees, such as their photosynthetic rates, remain largely unstudied. We quantified the diurnal cycle in leaf‐level net photosynthetic rate ( A ), stomatal conductance ( g sw ) and transpiration ( E ) in sun and shade leaves of male and female individuals of 14 Sclerocarya birrea trees in a northern Namibian semi‐arid agroforestry system and explained the observed trends by three environmental drivers (light, temperature and humidity). A generalised additive model with a thin‐plate regression spline smoother was applied to describe non‐linear diurnal variation in A , g sw and E . Results revealed a pronounced pre‐midday decline in A for sun leaves, from 5.5 μmol CO₂ m −2 s −1 in the morning to 2.4 μmol CO₂ m −2 s −1 in the late afternoon, while shade leaves showed a continuous decrease from 3.0 to 1.8 μmol CO₂ m −2 s −1 . Correspondingly, g sw declined from 0.07 to 0.04 mol m −2 s −1 , and E from 0.0012 to 0.0008 mol m −2 s −1 between morning and afternoon hours for sun leaves. Male trees exhibited higher A , g sw and E than females, suggesting secondary sexual dimorphism in gas‐exchange traits. Light was the best predictor of net photosynthetic rate and transpiration, whereas temperature was the best predictor of stomatal conductance. These findings highlight the complex interplay between environmental factors, leaf position and tree‐specific traits in shaping the photosynthetic performance of Sclerocarya birrea . Consequently, this knowledge enables better‐informed management and conservation strategies for this key savanna species.

Informal food trading is a cornerstone of urban livelihoods and food security in Namibia, yet traders operate under fragile conditions marked by limited capital, policy exclusion, and exposure to shocks such as COVID-19. Despite this vulnerability, traders exhibit resilience through everyday forms of social innovation. This study investigates how adaptive pricing, customer credit, and digital communication and e-payment practices function as pathways of resilience among 470 informal food traders in Windhoek, using Structural Equation Modelling to assess gender-differentiated determinants and outcomes. The analysis reveals that women’s adoption of adaptive pricing and digital tools is driven primarily by education and startup capital, while men’s innovation practices are shaped by vendor type and access to financing. Social innovations mediate the effects of these structural factors on enterprise growth, demonstrating that innovation acts as a critical mechanism linking resources and resilience. The study concludes that enhancing informal traders’ resilience requires policies that strengthen human and financial capital, improve digital inclusion, and recognize gendered differences in access to opportunity. It recommends targeted support for women’s entrepreneurial training, affordable credit, and digital infrastructure to transform the informal food sector into a more equitable and sustainable component of Namibia’s urban economy.

Tuberculosis (TB) burden concentrates in low-income settings and remains the leading global cause of death from a single infectious agent, despite that it is preventable and treatable. TB-associated lung diseases (TBALD), a broad range of respiratory abnormalities which can start before or during a TB episode, may increase morbidity. TBALD may persist after successful completion of TB treatment as post-TB lung disease (PTLD). PTLD varies in severity and is characterised by persistent respiratory symptoms and lung impairment that can significantly impact social activities, health-related quality of life, and long-term survival. Risk factors for PTLD include increasing age, smoking, HIV infection, delayed diagnosis, and poor socioeconomic conditions.Action to limit PTLD may be taken before TB develops through TB screening, early diagnosis and TB preventive treatment, during treatment of TB, and upon its completion. Early detection, clinical assessment, and tailored management (including smoking cessation, immunisation, addressing respiratory comorbidities, pulmonary rehabilitation and social protection) can mitigate impairment and disability. Healthcare providers and national programmes play a vital role through clinical follow-up, patient education, and integration of TBALD care into broader health and social protection services. Sustained funding and research are crucial for this and to develop new tools to enhance care.

<title>Abstract</title> This study explores the intersection of search engine optimisation (SEO) and repository as open access (OA) mandates gain prominence, academic institutions are increasingly called upon to enhance the visibility and accessibility of their scholarly outputs. This is largely facilitated through digital repositories and related OA initiatives, which serve as critical infrastructures for global knowledge dissemination. Openly available research enhances discoverability, fosters knowledge equity, and contributes meaningfully to national and regional development goals. This study investigates the <italic>global visibility</italic> of the University of Namibia's (UNAM) digital institutional repositories. A sample of fifty (50) digital resources from the UNAM Library's repositories was randomly selected and assessed through search queries across five widely used search engines: Google, Yahoo, Baidu, Yandex, and Bing. Search terms included subject-specific keywords and varied combinations of titles and descriptors. The findings reveal that Google significantly outperforms the other search engines in indexing and retrieving UNAM’s repository content, whereas visibility on the remaining platforms was negligible or non-existent. The study underscores the need for enhanced search engine optimization (SEO), improved metadata structuring, and strategic repository management to ensure broader access and visibility of African research outputs on the digital global landscape.

Background: Population ageing has emerged as one of the most significant demographic challenges of the twenty-first century, resulting primarily from sustained declines in fertility and improvements in life expectancy. These changes have altered population age structures worldwide, leading to a growing proportion of elderly persons aged 60 years and above. While India continues to possess a large young population, the pace of ageing is accelerating rapidly. The elderly population, estimated at about 153 million in 2025, is projected to reach nearly 347 million by 2050, indicating a profound demographic transformation with far-reaching social, economic, and health implications. In Assam, the process of population ageing reflects broader demographic transitions, including declining fertility, reduced mortality, and selective out-migration of younger adults. Traditionally characterized by a youthful population structure, the state is now witnessing a steady increase in the proportion of older persons. This emerging trend necessitates a systematic examination of the demographic dimensions of ageing in Assam to inform policy formulation, social welfare planning, and sustainable development strategies. Materials and Methods: The study employs a quantitative and descriptive research design based on secondary data sources. The elderly population is defined as individuals aged 60 years and above. To analyze the extent and pattern of population ageing in Assam, several demographic indicators are computed, including the Age–Sex Ratio, Old-Age Dependency Ratio (OADR), Ageing Index, and Median Age. Descriptive statistical tools such as percentages and trend analysis are used to examine changes in population structure over time. The results are presented through tables to enhance clarity and comparative analysis. Results: The analysis reveals a progressive increase in the proportion of the elderly population in Assam, indicating a clear shift toward an ageing demographic structure. The Old-Age Dependency Ratio has risen steadily, suggesting a growing dependency burden on the working-age population. Similarly, the Ageing Index indicates a significant increase in the elderly population relative to the child population. The age–sex composition of the elderly reveals a higher concentration of females in the older age groups, attributable to higher female life expectancy. Conclusion: The study concludes that population ageing has emerged as an important demographic reality in Assam. Driven by declining fertility, improving healthcare facilities, and increasing life expectancy, the proportion and absolute number of elderly persons have increased substantially over the past six decades.

ABSTRACTThe landscape of fear (LOF) framework predicts that prey adapt their behavior to mitigate predation risk, yet the framework's expression in resource‐limited, unfenced systems remains poorly understood. Across seven large herbivore species in an unfenced arid system, space use is governed by bottom‐up constraints while predator risk is buffered in time, producing consistent low diel overlap with nocturnal carnivores and trait‐dependent moderation of spatial responses. We used camera trap data from northwest Namibia to examine how five herbivore species (gemsbok Oryx gazella, southern giraffe Giraffa giraffa, greater kudu Tragelaphus strepsiceros, Hartmann's mountain zebra Equus zebra, springbok Antidorcas marsupialis) and two megaherbivores (black rhinoceros Diceros bicornis, African bush elephant Loxodonta africana) navigate bottom‐up environmental constraints and top‐down predation risk from lions (Panthera leo) and spotted hyenas (Crocuta crocuta). We tested four hypotheses: (1) that bottom‐up environmental constraints would explain more variance in herbivore space use than predator covariates; (2) that herbivores would reduce diel overlap (Δ) with nocturnal predators rather than vacating resource patches; (3) that megaherbivores would show minimal spatiotemporal avoidance of predators, relative to smaller herbivores; and (4) that herbivores would respond reactively to recent predator presence, rather than proactively by avoiding areas of chronic predator activity. Our findings support a hierarchical LOF in which bottom‐up constraints (dry‐season progression, visibility for grazers, habitat structure for browsers) contribute to herbivore space use and top‐down predator pressures guide temporal activity: most species exhibited strongly diurnal activity, resulting in low temporal overlap with nocturnal carnivores (Δ ≈0.11–0.21 for grazers; Δ ≈0.06–0.26 for browsers). By contrast, spatial responses to predator presence were modulated by environmental context, reinforcing the importance of spatiotemporal plasticity. These results advance understandings of predator–prey dynamics, particularly in dryland ecosystems. We suggest refinements to the LOF framework for multi‐predator, resource‐constrained landscapes.

This paper assesses the integration of Corporate Social Responsibility (CSR) within the policy framework of Namibia’s Sustainable Special Economic Zones (SSEZs). As Namibia transitions from the underperforming Export Processing Zones (EPZs) to SSEZs, the paper raises the question of whether the new policy sufficiently addresses the CSR deficiencies of its predecessor. Using a qualitative, interpretive methodology, the paper highlights significant policy and institutional gaps impeding effective CSR implementation, such as the absence of regulatory mandates, inadequate accountability mechanisms and disjointed governance. It suggests a multi-tiered intervention strategy comprising policy reforms, legal requirements and participatory governance mechanisms, to integrate CSR into the SSEZs design and operations. Drawing on international best practices, the paper presents a contextualised framework to improve social sustainability within Namibia’s industrial policy. The results emphasise the need to reconceptualise CSR as a fundamental and strategic component of sustainable economic development.