Search Results (79)

This study investigates the long-term impacts of climate change on crop yields by analyzing global historical data from 1961 to 2024 across 25 selected countries, to to reveal how historical weather patterns affected crop yields in the most vulnerable regions of the world. Utilizing crop yield data from FAOSTAT and weather time series from the World Bank Climate Knowledge Portal, three distinct climate risk groups of countries were defined: Group 1 (strong warming, stable precipitation), Group 2 (no significant warming, strong precipitation decrease), and Group 3 (mild warming, strong precipitation decrease). A Linear Mixed-Effects Model (LMM) was employed to quantify the non-linear impacts and interactions of climate variables, including annual temperature maximums, minimums, precipitation, warm and cold spell durations, and the Standardized Precipitation Evapotranspiration Index, on primary staple and cash crops. Results reveal a stark regional asymmetry. In temperate regions (Group 1), agrotechnological advancements have successfully cushioned climate shocks over the past decades, although this buffering effect faces biophysical limits due to non-linear temperature thresholds, particularly for root crops like potatoes and sugarbeet. In tropical–subtropical areas (Group 2) and the Mediterranean (Group 3), climate extremes exert severe pressure on vital crops. Prolonged warm spells significantly reduce yields for perennials like bananas, coffee, and dates, while other Mediterranean crops like olives thrive under longer warm spells. While country-specific institutional capacities often generate substantial yield heterogeneity, major exceptions emerge for staple crops like wheat in Group 2 and barley in Group 3, where low Intraclass Correlation Coefficients (ICC) demonstrate that regional climatic drivers override national boundaries. The findings underscore that universal climate strategies are inefficient, and policymakers must prioritize crop-specific and localized adaptation frameworks for future food security. Full article

Forests cover nearly one-third of the Earth’s land surface and are subject to increasing anthropogenic pressure, including unauthorised construction, infrastructure expansion, and habitat fragmentation. Detecting buildings concealed beneath forest canopy is essential for environmental monitoring and territorial surveillance, yet optical satellite imagery fails under persistent cloud cover and dense vegetation, and no existing approach provides reliable detection across contrasting forest ecosystems. We address this gap by proposing a hybrid SAR-based detection framework that combines twelve physically interpretable Scattering-Informed SAR Features (SISF)—derived from electromagnetic scattering theory across amplitude, polarimetric, temporal, and texture dimensions—with a universal Convolutional Neural Network, integrated through probability-level fusion with isotonic regional calibration. Rather than relying on individual feature thresholds, the framework identifies buildings through their characteristic multidimensional scattering signature—a combination that remains discriminative across biomes where any single SAR descriptor would fail. The framework was evaluated on a novel 7721-object multi-biome benchmark spanning forest-steppe (Kazakhstan), boreal forest (Komi Republic, Russia), and tropical rainforest (Brazil, Pará). The final Fusion + Regional Calibration model achieved an overall F1-score of 0.803 on the held-out test set (N = 1545), outperforming single-model baselines by up to 17 percentage points. Regional F1-scores ranged from 0.727 (Kazakhstan) to 0.944 (Komi Republic), with detection performance remaining robust under partial canopy occlusion (F1 = 0.911, versus 0.903 for unobscured buildings). An empirical inverse relationship between hard negative proportion and detection F1-score was identified within each biome, with the 28–35% proportions present in our sampled regions reported as a preliminary observation rather than a generally optimal range—a dataset design finding not previously reported in the literature. The proposed framework provides a physically interpretable solution for SAR-based building detection under forest canopy, demonstrating consistent performance across three contrasting forest biomes, with direct applications to environmental monitoring and territorial surveillance in forested regions. Full article

This research addresses the reception and variations in the Modern Movement in the French Caribbean, focusing on the urban transformation of Fort-de-France, Martinique, between 1927 and 1986. Through a critical methodology based on decentralized perspectives and “situated gazes,” this study challenges traditional historiographical narratives that often subordinate tropical architecture to mere simplified derivatives of European metropolises. Utilizing the development and implementation of the ARMOMA platform (Architecture du Mouvement Moderne en Martinique)—a specialized digital archive and cartographic database—this work documents, spatially visualizes, and analyzes the region’s modern heritage. Methodologically, it examines a specific sample of 77 state-owned buildings divided into three key typologies—educational (34), institutional (30), and sanitary (13)—extracted from a wider urban universe of 332 modern works, evaluating their spatial relations with 171 residential architectures. Rather than constituting simple transpositions of metropolitan models, these infrastructures reveal processes of climatic, material, and cultural adaptation that contributed to the emergence of a specific form of Caribbean tropical modernism. The findings show how this localized practice reinterpreted Western rationalism through hybrid construction techniques, passive environmental strategies, and local building knowledge. In conclusion, the study highlights that, while architecture commonly serves as an instrument of institutional representation, in Martinique this role acquired particular relevance following the 1946 Departmentalisation. Within this framework, the French state promoted a range of public architectural typologies in Fort-de-France that materialized the expansion of welfare policies and administrative modernization. These developments accompanied the consolidation of the Welfare State in Martinique and continued until the implementation of the Decentralization Laws of 1982–1983. Full article

Dengue fever, a rapidly spreading mosquito-borne viral disease, poses a major global health issue, particularly in tropical and subtropical regions. The absence of a universally effective vaccine against all four dengue virus serotypes necessitates continued exploration of novel vaccine strategies. This study evaluated a PrM-derived multiple antigenic peptide (MAP) vaccine candidate in BALB/c mice. Molecular docking analyses predicted favourable interactions of the selected PrM-derived B-cell epitope with both human (human BCR Fab region PDB ID: 5IFH) and mouse (mouse BCR PDB ID: 8EMA) B-cell receptors, supporting its antigenic potential. ChemSketch was used to develop the PrM–MAP vaccine construct, which was then commercially synthesized. Mice received single, double, and triple booster doses of the vaccine, while control groups received either PBS or adjuvant alone. Humoral immune responses were measured by ELISA, and safety was evaluated through in vitro cytotoxicity assays on HEK293 cells and the in vivo histopathological examination of major organs. Mice immunized with a single booster dose produced significant levels of PrM-specific antibodies compared to subsequent booster doses, suggesting variability in the humoral response elicited. Optimal coating concentrations in ELISA demonstrated the importance of antigen concentrations in the sensitivity of the assay. The safety evaluation indicated high cell viability, up to 150 µg/mL of PrM–MAP, in HEK293 cells, and an absence of significant histopathological damage in treated animals. The PrM–MAP vaccine construct elicited a detectable humoral immune response while demonstrating a high safety profile in vitro and in vivo. These findings indicate the potential of MAP-based vaccine platforms as promising candidates for further development against the dengue virus. Full article

Off-grid residential microgrids in tropical regions require storage architectures capable of maintaining renewable electricity supply under variable solar resources, evening demand peaks, and diverse household consumption levels. In PV–battery–hydrogen systems, however, economic indicators can be difficult to interpret when software-reported costs are compared directly with externally calculated LCOE values based on different accounting conventions. This study presents a metric-reconciled techno-economic reconstruction approach for retained PV–battery–hydrogen microgrid configurations serving off-grid residential demand in Chetumal, Mexico. The objective is not to introduce a new global optimization or to claim the universal superiority of a specific architecture, but to separate archived HOMER Pro benchmark outputs from an external techno-economic model (TEM). The TEM reconstructs net present cost, scheduled replacements, salvage treatment, discounted delivered electricity, HOMER-derived LCOE, TEM-derived LCOE, sensitivity indicators, and storage role metrics using declared accounting assumptions. The approach is applied to two representative residential demand scenarios of 16.67 and 53.42 kWh/day. Both retained configurations achieved a 100% renewable fraction with negligible unmet load. Battery discharge increased from 827.12 kWh/year in the low-demand case to 6125.52 kWh/year in the high-demand case, highlighting the increasing role of the battery in short-duration balancing. In contrast, the hydrogen pathway acted as a delayed-backup layer by converting surplus PV electricity into hydrogen and later recovering it through PEM fuel cell generation. The TEM closely matched the HOMER-derived LCOE benchmark, with deviations below 4%, yielding TEM-derived LCOE values of 0.3320 and 0.3571 USD/kWh for the low- and high-demand cases, respectively. Sensitivity analysis showed that delivered electricity, discount rate, PV cost, and battery cost were the main LCOE drivers, while deterministic multi-parameter scenarios confirmed the combined influence of financing, component costs, O&M, PV degradation, and electricity delivered. Overall, the proposed approach provides an auditable basis for metric reconciliation, early-stage technology assessment, and storage role interpretation in tropical off-grid microgrids. Future extensions should include architecture-level re-optimization, flexible loads, degradation-aware modeling, and part-load component behavior. Full article

The accumulation of agricultural residues represents a major environmental challenge in developing countries, particularly in tropical regions where inadequate waste management contributes to environmental degradation. Vermicomposting has emerged as a sustainable technology capable of transforming organic waste into nutrient-rich fertilizers through the combined activity of earthworms and microorganisms. This study evaluated the influence of different agricultural residues on the physicochemical properties of vermicompost under tropical conditions in Mozambique. The experiment was conducted at the experimental field of the Catholic University of Mozambique—Faculty of Engineering in Chimoio district, using three substrate types: leguminous residues (T1), cereal residues (T2), and horticulture residues (T3). Each treatment was combined with poultry manure in a 1:1 ratio. Vermicomposting was carried out using Eisenia fetida. Because treatments were not independently replicated, results are presented as descriptive physicochemical characterizations (means ± SD of analytical subsamples). All treatments produced vermicompost with physicochemical characteristics consistent with established maturity criteria: pH 8.03–9.07, moisture 50–76%, and electrical conductivity 527–939 µS/cm, C/N ratio ranged from 15.56 to 20.19, total nitrogen ranged from 1.2 to 1.8%, phosphorus from 0.6 to 0.9%, and potassium from 1.1 to 1.5%. T1 (leguminous residues + poultry manure) showed the highest nutrient concentrations and lowest C/N ratio. These descriptive findings suggest that vermicomposting represents a promising strategy for recycling agricultural residues into vermicompost with characteristics consistent with established maturity criteria, highlighting the importance of substrate selection. The findings suggest that vermicomposting is a promising strategy for sustainable waste management and soil fertility improvement in tropical smallholder systems. Full article

Background: Schistosomiasis remains a significant neglected tropical disease in Kenya, but its presence in the western/northern Lake Turkana region is poorly characterised. We conducted an exploratory serosurvey to assess evidence of Schistosoma spp. exposure and a diagnostic accuracy study to evaluate dried blood spots (DBSs) for field serology. Methods: We performed a cross-sectional survey in adults (≥18 years) from six communities in the western/northern and shoreline area of Turkana Lake, excluding individuals with >6 months of residence in other Kenyan endemic areas. Capillary blood was collected on DBSs and tested centrally using ELISA for Schistosoma spp. IgG. In parallel, DBS cards performance was compared with paired routine serum ELISA in 23 patients assessed for suspected schistosomiasis at our centre. Results: We enrolled 155 participants (60% men; median age 30 years), with nearly universal reported freshwater contact (154/155, 99.4%). In the validation study, DBS values were lower than serum values (mean bias 0.27), with moderate correlation (r = 0.54) and modest discrimination (AUC 0.65; sensitivity 80% and specificity 50% at OD index >0.8). The median DBS ELISA OD index for the 155 participants was 0.55 (IQR, 0.34–0.79). Six samples exceeded 0.8, but these values were low, and all had negative IHA (<1/80), yielding no confirmed seropositive cases. Conclusions: These findings suggest low or absent sustained transmission in the sampled communities during the study period and indicate that DBS-based serology is operationally feasible but requires careful calibration and confirmatory testing for robust field inference. Full article

Accurate rice detection is essential for food security, sustainable agriculture, and environmental monitoring. Satellite time series observations provide scalable capabilities for rice detection; however, their application in tropical regions is challenged by persistent cloud contamination, asynchronous crop development cycles, and temporal misalignment among multisensor observations, which reduce classification reliability. This study introduces Multivariate Robust Time Series Boosting (MRTS-Boosting), a quality-aware framework for multivariate time series classification (TSC) designed to improve robustness under noisy and irregular observational conditions. The framework integrates quality-weighted feature construction, joint extraction of full-series and interval-based temporal features, and a flexible multivariate formulation that accommodates heterogeneous satellite inputs without strict temporal alignment. Performance was evaluated using synthetic datasets with controlled cloud contamination, 103 benchmark datasets from the University of California, Riverside (UCR) TSC Archive, and 3261 real-world rice field observations from Indonesia. Comparisons were conducted against representative whole-series, interval-based, shapelet-based, kernel-based, and ensemble classifiers. MRTS-Boosting achieved up to 87% accuracy under severe cloud contamination, an average rank of 2.7 on noise-augmented UCR datasets, and 93% accuracy with Cohen’s kappa of 0.76 for Indonesian rice detection, while maintaining moderate computational cost. These results demonstrate that MRTS-Boosting provides a robust, scalable, and computationally efficient framework for satellite-based rice detection. The framework remains competitive in univariate settings while benefiting from multisensor integration, indicating that performance gains arise from both methodological design and the effective use of heterogeneous data. MRTS-Boosting is therefore well-suited for precision agriculture applications under challenging observational conditions. Full article

The transition towards a circular bioeconomy in developing regions is frequently hindered by operational failures caused by feedstock discontinuity. Whilst biochemical potential is traditionally the primary selection criterion, this study postulates that logistic reliability serves as the governing constraint. To validate this strategic reorientation, a decision-making framework was developed and applied to a representative tropical agro-industrial region. A sensitivity analysis comparing objective, subjective and neutral weighting scenarios identified annual residue production as the dominant factor. Results established cattle manure as the universal baseload substrate essential for mitigating seasonality, outweighing higher-yielding but intermittent agricultural residues. Spatial analysis revealed distinct territorial vocations, identifying a high-availability rice–livestock cluster in the south suitable for centralised industrial plants and dispersed cassava–livestock nodes in the centre favourable for decentralised digestion. Furthermore, the assessment of energy autonomy demonstrated that the prioritised co-digestion scenarios could cover local residential electricity demand between 1.5 times and 81 times. Crucially, residues favoured by expert judgement proved logistically unfeasible despite superior theoretical yields. This data-driven approach demonstrates that successful substrate selection must transcend theoretical yield maximisation to prioritise supply chain reliability, providing a robust roadmap for de-risking bioenergy investments and ensuring regional energy autonomy. Full article

Background: Mycetoma is a chronic infectious disease caused by bacteria or fungi which typically affects the skin, deep tissues, and bones. This case involves bone mycetoma in an immunocompetent patient, marking the first known instance of actinomycetoma caused by Gordonia rubripertincta. Case Report: A 25-year-old male presented with severe pain and deformity in his left foot, symptoms that began five years prior after stepping on a wire. Initial surgery provided temporary relief, but symptoms worsened over time. Doxycycline treatment was ineffective. Skin biopsies were performed. The patient was diagnosed with actinomycetoma, with Gordonia rubripertincta identified in culture. Although initial improvement was observed with amoxicillin–clavulanate treatment, the condition later worsened, requiring long-term penicillin therapy and eventual surgical excision. Despite treatment, symptoms persisted, leading to a bone biopsy that showed no microorganism growth. A six-week course of ampicillin–sulbactam and ciprofloxacin, along with offloading, decreased pain and stabilized radiological findings. Conclusion: Gordonia infections mean there is no universally established treatment protocol. This case underscores the diagnostic and therapeutic challenges associated with mycetoma, particularly in non-tropical regions. Full article

Saprotrophic and lignocellulolytic fungi from tropical areas especially represent a promising yet relatively underexplored frontier for both taxonomy and applied research. This makes ex situ conservation through culture collections of paramount importance. Here, 10 lignocellulolytic strains isolated from the State of São Paulo (Brazil) and deposited in the Brazilian Culture Collection (now CCIBt) were identified through the ITS region. In order to prevent accidental losses, these strains have been shared with the collection of the University of Milano—Department of Food, Environmental and Nutritional Sciences (DeFENS), as well as the MicUNIPV Fungal Research Culture Collection—University of Pavia (Italy). Most of the fungal species in the examined set exhibit a neotropical distribution, while 3 out of 10 are nowadays recognized as subcosmopolitan despite their prevalence in the neotropical area. One holotropical, one cosmopolitan and one holarctic species are also present. Based on the literature, 8 out of the 10 characterized species are known to produce psilocybin (e.g., Psilocybe cubensis and Candolleomyces candolleanus) and/or enzymes with potential applications in environmental and medical biotechnology (e.g., Lentinus crinitus). All 10 strains were described for their micro- and macro-characteristics; their growth rate was evaluated and culture pictures provided. Taxonomic and nomenclatural controversies concerning Candolleomyces candolleanus, Cubamyces lactineus and Pycnoporus sanguineus are discussed. Full article

Despite the extensive cultivation of Moringa trees in tropical regions, understanding of accession-specific performance across diverse agroecological zones remains inadequate. Thus, this study evaluated the growth, adaptability, and leaf yield performance of 12 Moringa accessions (11 M. oleifera and 1 M. stenopetala) over three years in a subtropical climate (Pretoria, South Africa). Seeds were planted in seedling trays in the glasshouse at the University of Pretoria’s experimental farm. Vigorous seedlings were transplanted to the field at the Roodeplaat experimental site of the Agricultural Research Council two months after establishment, following a randomized complete block design (RCBD). Data were measured on establishment (emergence, survival), growth and yield parameters, and monitored plant health via leaf greenness, vigour, chlorosis, and pest and disease incidence. Accessions exhibited substantial variation for most traits, except for stem diameter. Moringa stenopetala showed the highest initial emergence rate but later displayed lower survival rates than most M. oleifera accessions. Survival rates, morphological features (plant height, canopy diameter, and branching), visual scores for leaf greenness and plant vigour, and leaf yield (fresh and dry) varied considerably among the accessions. Moringa oleifera A2 consistently performed well, exhibiting vigorous growth, the maximum survival rate (78%), and fresh leaf production (6206 kg ha⁻¹). Accessions A3 and A8 showed intermediate yield and longevity, indicating potential for cultivation or breeding. Conversely, M. oleifera A10 and M. stenopetala markedly underperformed in most traits, limiting their cultivation potential. Based on multi-year performance, A2 is suggested for large-scale cultivation due to its vigour, yield, and stress tolerance, while A3 and A8 hold breeding potential. The study emphasizes the critical role of genetic variation and selection in enhancing Moringa productivity under subtropical environments. Future work should focus on genetic characterization and agronomic practices optimization of superior accessions. Full article

Outdoor thermal comfort in tropical cities is increasingly threatened by rapid urbanization, high humidity, and insufficient climate-sensitive planning. Despite numerous studies on urban heat mitigation, there is a lack of empirical and numerical research that evaluates the synergistic application of bioclimatic strategies under humid tropical conditions. This paper addresses this gap by analyzing the combined effect of arborization, dry mist systems, water bodies, and sprinklers on outdoor thermal comfort at the Víctor Levi Sasso Campus of the Technological University of Panama. We hypothesized that synergistic application of these strategies provides greater thermal comfort improvements than isolated interventions. The central research question guiding this study was: To what extent can combined bioclimatic strategies enhance outdoor thermal comfort compared to individual strategies in humid tropical environments? To answer this, a hybrid methodology was employed, integrating ENVI-met dynamic simulations with in situ measurements and thermal comfort surveys based on the physiological equivalent temperature (PET) index and subjective comfort scales. The results demonstrate that combined strategies achieve superior reductions in mean radiant and surface temperatures while improving subjective comfort perceptions, highlighting their potential for context-sensitive urban design in tropical regions. Full article

University campuses in rapidly urbanizing regions face increasing pressure to balance infrastructure development with environmental sustainability, yet their carbon storage potential remains largely unexplored in sub-Saharan Africa. This study assessed land use changes, carbon storage dynamics, and economic valuation across three Ghanaian universities, University of Ghana (UG), Kwame Nkrumah University of Science and Technology (KNUST), and University of Cape Coast (UCC), from 2017 to 2023, and evaluated five future scenarios using the InVEST carbon model. Land use analysis employed ESRI 10 m annual land cover data, while carbon storage was estimated using regionally appropriate carbon pool values, and economic valuation applied Ghana’s social cost of carbon ($0.970/tCO₂). Historical analysis revealed substantial carbon losses: UG declined by 17.1% (19,695 Mg C), KNUST by 29.5% (20,063 Mg C), and UCC by 7.9% (3292 Mg C), due to tree cover conversion to built areas. Scenario modeling demonstrated that infrastructure-focused development would cause additional losses of 4211–6891 Mg C, while extensive tree expansion could increase storage by 1686–5227 Mg C. Economic analysis showed tree expansion generating positive net present values ($1612–$5070), while infrastructure development imposed costs (−$4028 to −$6684). These findings provide quantitative evidence for sustainable campus planning prioritizing carbon conservation in tropical institutional landscapes. Full article

Soil erosion threatens agricultural sustainability in tropical upland areas. This study evaluated soil erosion in Nam Dong district, Central Vietnam, using the Universal Soil Loss Equation (USLE) model and the Analytic Hierarchy Process (AHP) based on local stakeholder input. The USLE employed spatial data on rainfall, soil, topography, and land cover, while the AHP incorporated the perspectives of nine diverse community members. Both models identified the mountainous central region as most at risk; the USLE classified 62% of land as extreme erosion, whereas the AHP classified 82% as severe. These differences reflect the empirical approach of USLE versus the perception-driven results of the AHP. The study found that applying both methods independently and comparing their outcomes can yield different soil erosion scenarios. Furthermore, additional research is recommended to explore the use of the AHP as a tool for calibrating the relative importance of input factors in the USLE model. This approach could enhance the accuracy of soil erosion risk assessments and support more effectively targeted conservation strategies in complex upland landscapes. Full article