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Compressive strength optimization of the ambient-cured metakaolin-based geopolymer mortar using the Taguchi design approach
(Elsevier, 2025-05-16) Hashimu Hamisi; Chambua, Safiel; Mansouri, Said; Hicham, Majdoubi; Yusufu Abeid; Chande, Jande,; Youssef, Tamraoui; Askwar, Hilonga
This study utilized raw natural kaolinite sourced along Pugu hills, Tanzania, as the aluminosilicate source. To optimize the compressive strength, nine (9) metakaolin geopolymer formulations were activated using the Taguchi technique at various Na2SiO3/NaOH mass ratios, NaOH concentrations, and alkaline/binder ratios. The ideal parameters were 12 M, 2.5, and 0.8 Na2SiO3/NaOH mass ratios, NaOH concentration, and alkaline/binder ratios, respectively, resulting in a compressive strength of 70.38 MPa. When the optimized geopolymer was exposed to a higher temperature, its compressive strength increased by 15.57 % at 200°C compared to room temperature. Compressive strength decreased with exposure over 200°C, and weight loss and water absorption were directly correlated with this. The SEM results show that the former lacks a well-linked geopolymer network when comparing weak and superior formulations. High-strength formulations are verified to include higher levels of orthoclase and albite, according to Rietveld refinement and XRD research. The XRD patterns showed the development of sanidine, chrysotile, and nepheline crystalline phases at temperatures higher than 200°C, which may have contributed to the decrease in strength of the geopolymer specimens.
Tanzania: The Eastern Arc Mountains Forests as World Natural Heritage— Status and Future Prospects
(Springer, 2025-05-30) Munishi, Linus
This is an open access book. This professional volume provides scientific background and practical guidance on forest management in light of ecological connectivity. Readers will gain a great understanding of shifting species in response to climate change and the resulting loss of various resources. The main drivers of these variations are the quality of the availability, quantity, and quality of habitats in the landscape, the genetic diversity of species populations, and the ability to navigate through a fragmented landscape matrix. The connectivity of habitats is gaining importance in the combat of both, the biodiversity crisis and the climate change crisis. Improving ecological connectivity, however, does not automatically benefit all species, as the examples described in the book demonstrate. Specific planning tools, active monitoring protocols, and management measures are needed to increase the benefit for species with low dispersal and small population size, which generally fail to migrate. Assisted migration can help to prevent species extinction, but also offer opportunities for pathogens to cross geographical barriers. The vast majority of the known diversity of plants, fungi, vertebrates, and invertebrates depends on forest ecosystems. This volume helps to spread this message and prepare students for their later careers in the forestry sector, while also informing active practitioners and policy makers. This is an open access book.
Monitoring Methods for the Protection of Connectivity in Forest Ecosystems
(Springer, 2025-05-30) Oettel, Janine; Thalinger, Bettina; Szukala, Aglaia; Munishi, Linus; Lapin, Katharina
Forest ecosystems face increasing threats from climate change, resource exploitation, and other anthropogenic disturbances causing biodiversity loss and habitat fragmentation. The conservation priority of connected, healthy forests necessitates robust monitoring that covers the landscape, ecosystem, species, and genetic levels and employs direct as well as indirect methods. Connectivity objectives encompass patch colonization, prioritization, and landscape assessment at multiple scales. Monitoring landscapes and forest ecosystems involves assessing their physical attributes and functional diversity to understand biodiversity, land-use changes, and threats like deforestation and climate impacts. Remote sensing offers large-scale data collection, while terrestrial surveys including laser scanning provide detailed insights into forest dynamics. Challenges include scale issues, standardization, and potential oversights in finer-scale variations. While species monitoring captures long-term shifts in abundance or distribution, it can be resource-intensive and challenging for elusive species. Alternatively, molecular methods such as the use of environmental DNA (eDNA) can be effective for community monitoring, with DNA analysis being particularly effective for detecting the presence of endangered or elusive organisms and providing spatial and temporal high-resolution data for effective conservation and management. Gene-based monitoring traces changes in individual species’ genetic parameters over time. Genetic indicators, which have recently been included in biodiversity monitoring standards, provide essential insights into connectivity and adaptive capacity. Landscape genetics combines conservation genetics and ecology to understand gene flow barriers and facilitators: population synchrony signals functional connectivity. Although genetic monitoring demands great technical expertise, it is less time-consuming than conventional methods. For future forest connectivity monitoring, a combination of various approaches is conceivable. Existing connectivity indicators need rigorous evaluation in terms of their sensitivity to environmental impacts. Dynamic models and novel indicators along with data sharing and collaboration will be crucial for future efforts in connectivity monitoring.
DENV-2 Circulation and Host Preference Among Highly Anthropophilic, Outdoor-Biting Aedes aegypti in Dar es Salaam, Tanzania
(MDPI, 2025-06-05) Tenywa, Frank; Hälg, Silvan; Makame, Haji; Moore, Jason; Dogan, Osward; Mapipi, Harubu; Machange, Jane; Lilolime, Nasoro; Hofer, Lorenz; Batao, Lewis; Mwamlima, Tunu; Müller, Pie; Moore, Sarah
In Tanzania, dengue outbreaks have occurred almost annually over the past
decade, with each new outbreak becoming more severe. This study investigated the preva-
lence of dengue virus (DENV) serotypes in the wild Aedes aegypti and their blood sources
to determine human exposure risk in Dar es Salaam, Tanzania. A two-year longitudinal
survey was conducted in the Ilala, Kinondoni, and Temeke districts of Dar es Salaam
to sample Ae. aegypti mosquitoes using Biogents Sentinel trap (BGS), Prokopack aspira-
tion, and Gravid Aedes trap (GAT). Collected mosquitoes were pooled in groups of 10
and tested for DENV1–4 serotypes using reverse transcription polymerase chain reaction
(RT-qPCR). Blood meal sources were identified using an enzyme-linked immunosorbent
assay (ELISA). Of 854 tested pools, only DENV-2 was detected and was found in all three
districts: Temeke (3/371 pools), Ilala (1/206 pools), and Kinondoni (1/277 pools). Blood
meal analysis showed a strong preference for humans (81%) as well as for mixed blood
meals that contained human blood and other hosts (17%). Out of 354 collected hosts seeking
Ae. aegypti, 78.5% were captured outdoors and 21.5% indoors. This study confirms the
circulation of DENV-2 in Ae. aegypti populations, indicating a potential dengue outbreak
risk in Tanzania. This study also demonstrates that xenomonitoring may be feasible in this
setting. The mosquitoes’ strong preference for human hosts and predominance in outdoor
settings pose challenges for dengue control effort
Enhancing Food Security By Fostering Gender Equality In The Context Of Climate Change Variability In Tanzania: A Review
(J. Product. & Dev., 2025) Mkangara, Mwanaisha; Mnabe, Anneth; Zekeya, Never; Mbega, Ernest; Chacha, Musa; Nyange, Tatu
Gender equality in agricultural productivity has boosted food security in this era of climate change dynamics. The equal treatment of women and men in resource allocation, access to credit, education and leadership minimizes the gender gap and increases women's representation in coping with climate change impacts. Focusing on equal rights for women in resource utilization to enhance food security and addressing mitigations and adaptation measures minimize the exacerbation of greenhouse gas (GHG) emissions. The review identified the role of climate-smart agriculture (CSA) for farmers to increase productivity with minimum GHG emissions and how understanding resource-smart production and consumption chains contributes to reducing production footprints. The mitigation measures discussed to reduce climate change variability are education, implementing treaties and agreements, agriculture and food systems, carbon credit, urban planning and building designs. The climate change adaptations highlighted are adapted crops, ecosystem restoration, early warning systems, climate-resilient infrastructure and national adaptation plans. Therefore, addressing climate change challenges and gender inequalities through climate action’s innovative strategies is vital for food security.