This study evaluated the growth performance, carcass characteristics, economic efficiency, health status, and growth patterns of three commercial broiler strains (Hubbard, Cobb 500, and Ross 308) reared under humid tropical conditions in Ghana. A total of 300 day-old chicks were allocated to a completely randomized design with five replicate pens per strain and reared for six weeks under uniform management conditions. Performance traits, carcass and internal organ characteristics, mortality, and morbidity were assessed, and growth patterns were modeled using the Gompertz function. Although initial body weights differed among strains, no significant differences were observed in final body weight, weight gain, feed intake, feed conversion ratio, or feed cost per kg weight gain. Carcass characteristics were also comparable across strains. Cobb 500 exhibited numerically higher growth rate and asymptotic weight based on the Gompertz model, whereas Ross 308 showed slower growth but lower mortality and greater development of digestive organs, suggesting improved adaptability to tropical conditions. Overall, the findings indicate that while the three broiler strains demonstrate similar production performance under tropical conditions, differences in growth dynamics and survivability may influence strain suitability. These results highlight the importance of balancing growth efficiency with environmental adaptability when selecting broiler genotypes for humid tropical production systems.
This study investigates the climatic sensitivity and long-term performance stability of a semi-transparent photovoltaic (STPV) system operating in a tropical coastal region of Indonesia. Using a decade of daily meteorological data (2012-2022), we developed a multivariate regression-based environmental modelling approach to evaluate the influence of key climatic variables on performance ratio (PR) and energy yield. Three modelling structures were considered, including a full-variable model, a simplified model based on global tilted irradiance (GTI) and ambient temperature, and a constant PR benchmark. The results indicate that GTI and temperature are the dominant climatic drivers, accounting for most of the meaningful variability in PR. The simplified GTI-temperature model achieved predictive performance comparable to the full model, suggesting that a parsimonious formulation can retain most of the explanatory power while reducing data requirements. The estimated PR values ranged between 0.78 and 0.80, consistent with reported values for tropical photovoltaic systems. Despite observable seasonal and interannual climatic variability, the system exhibited relatively stable performance over the study period, with no clear monotonic decline in energy yield. These findings highlight the applicability of simplified environmental models for performance assessment and planning in data-scarce tropical coastal regions.
The North Caribbean Coast Autonomous Region of Nicaragua (RACCN) is one of the most vulnerable areas to tropical cyclones (TCs), a condition exacerbated by climate change and internal structural disparities. Despite its historical exposure to TCs, significant gaps remain in the systematic analysis of its vulnerability. This research assesses the vulnerability levels of RACCN municipalities to TCs by constructing a Tropical Cyclone Vulnerability Index (VItc), and a municipal typology based on exposure, susceptibility, and adaptive capacity factors. Twelve indicators were selected, normalized, and analyzed using factor analysis with varimax rotation. The resulting sub-indices were integrated through weighted aggregation, and a municipal typology was developed using the Natural Breaks (Jenks) classification method. Findings reveal marked territorial disparities among municipalities. Bonanza exhibits high exposure and susceptibility combined with low adaptive capacity while Waslala demonstrates greater structural resilience. The VItc enabled the identification of three municipality clusters, with differentiated vulnerability profiles, facilitating the design of targeted interventions. The results underscore the role of social, demographic, and infrastructure factors in shaping local vulnerability. Despite limitations in data availability, the VItc provides a diagnostic tool that may help identify priority areas and the development of strategies for disaster risk reduction and resilience in the RACCN. The study highlights the need to improve data availability and strengthen institutional capacities. It also points to important directions for future research, including the integration of territorial, socioeconomic, and gender-sensitive approaches, as well as dynamic variables such as climate projections, land-use change, and migration, together with participatory methods that integrate local knowledge.
Accurate modelling of tropical cyclones (TCs) is essential for reliable storm surge simulations, as TCs provide the primary external forcing. While deep learning models have demonstrated effectiveness in TC modelling, a challenge remains regarding the limited diversity of TCs in reanalysis data used for training-specifically, the scarcity of extreme TC events. This study proposes a physics-based data augmentation method that utilizes a numerical weather prediction (NWP) model to physically generate TCs lying beyond the range of reanalysis data. Subsequently, focusing on small-sized yet intense TCs as extreme cases, a model-originally pre-trained solely on reanalysis data-was fine-tuned using this augmented dataset to convert a parametric TC model (PM) field into an NWP-like field. Validation using test data mimicking extreme TCs and a storm surge hindcast of TC Faxai (a compact, intense TC that struck Tokyo Bay in 2019) revealed that the PM failed to simulate storm surges where topographic effects on the wind field are significant, and the pre-trained model underestimated wind speeds and storm surges. In contrast, the fine-tuned model successfully captured the spatiotemporal features of the extreme TCs and the peak storm surges upon TC landfall, achieving the lowest RMSE for storm surges across all TCs and tide gauges. These results suggest that physics-based data augmentation can effectively extend the applicability of deep learning models for TC and storm surge modelling to extreme events.
Genetic diversity is critical for crop improvement, germplasm conservation, and sustainable agriculture. It enables breeders to assess genetic relationships among germplasm, select suitable parents, and develop resilient varieties. In this study, a total of 11,203 single nucleotide polymorphism (SNP) markers were used to evaluate the genetic diversity of 93 maize inbred lines adapted to the East African tropical highlands. The results revealed moderate genetic diversity across the panel. Gene diversity, polymorphic information content (PIC), and genetic distance ranged from 0.10 to 0.67, 0.10 to 0.59, and 0.03 to 0.52, with mean values of 0.46, 0.40, and 0.44, respectively. Linkage disequilibrium (LD) analysis identified 36,904 SNP pairs (7.5% of 487,225 comparisons) showing relatively strong LD (r2 ≥ 0.20), with an overall mean r2 of 0.067. Genome-wide LD decayed to r2 = 0.2 at approximately 93.82 kb, suggesting rapid decay and substantial historical recombination. Analysis of molecular variance (AMOVA) revealed that 95% of the total variation resided within germplasm source groups, whereas 5% was attributed to differences among groups, indicating low to moderate genetic differentiation. Multivariate analyses, including neighbor-joining, principal component analysis, and population structure analysis, consistently grouped the lines into three clusters, which largely corresponded with pedigree information. The observed diversity highlights the presence of valuable alleles that can be harnessed in maize breeding to enhance productivity and resilience in highland environments. Furthermore, the identified SNP markers in this study provide a useful genomic resource for future studies, including marker-trait association studies aimed at identifying genomic regions underlying key agronomic traits and accelerate genetic improvement in challenging environments.
Entamoeba histolytica is a protozoan parasite that causes amebic colitis, a leading cause of severe diarrheal disease worldwide, and amebic liver abscess, the most common extraintestinal manifestation of infection. The disease burden is highest in resource-limited settings but remains clinically important in travelers and men who have sex with men in non-endemic regions. Although most infections are asymptomatic, severe and fulminant disease is associated with high mortality, particularly among individuals exposed to corticosteroids or other forms of immunosuppression. The increasing use of molecular diagnostic tools has improved understanding of the epidemiology of E. histolytica and enabled distinction from morphologically identical but nonpathogenic Entamoeba species; however, these diagnostics remain underutilized in many endemic settings due to cost and infrastructure limitations. Treatment options remain limited, with nitroimidazoles constituting the only drug class available for symptomatic invasive disease, leaving few alternatives for patients who cannot tolerate therapy or in the event of emerging resistance. Despite advances in understanding parasite pathogenesis and the application of high-throughput technologies, no licensed vaccine exists, and progress toward vaccine development has been minimal. These persistent gaps highlight the need to reprioritize amebiasis as a neglected tropical disease and to accelerate investment in diagnostics, therapeutics, and preventive strategies.
Seed germination analysis often ignores temporal dynamics and non-germinating fractions, limiting biological inference. Conventional methods assume all seeds germinate, which is unrealistic for heterogeneous forest seed lots. Long-term survival (cure fraction) models offer a framework to address this limitation. This study uses seed germination of native Brazilian forest species to demonstrate the applicability and advantages of long-term modeling. Five independent datasets from native Brazilian forest species were analyzed under varying environmental conditions, including temperature, osmotic stress, light, and seed traits. Germination was modelled as a time-to-event process using parametric (log-normal, Weibull, log-logistic) and semiparametric (Cox) approaches with long-term survival models. Kaplan-Meier estimators were used for initial exploration and model comparison. Model selection was based on graphical fit and Cox-Snell residuals. All datasets showed a fraction of non-germinated seeds, with germination curves stabilizing below 100%, which corroborates the use of cure models. Long-term models consistently outperformed traditional survival approaches, providing better fit and biological interpretability. Environmental factors differentially affected incidence and latency components: extreme temperatures and water stress significantly reduced the probability of germination, while having smaller effects on germination speed. The probability of germination varied widely between species and conditions, from 10% to 95%. The models also revealed complex interactions between environmental and seed characteristics that influence germination dynamics. This study demonstrates that long-term survival models provide a robust, biologically realistic statistical framework for analyzing germination data from forest seeds. Partitioning the germination process into incidence (probability of germination) and latency (time to germination) components enabled key advances. First, it allowed precise quantification of the fractions of germinating and non-germinating seeds. Second, it provided more accurate and informative estimates than traditional survival methods. Finally, it enabled the isolation of the effects of environmental factors on germination capacity and speed.
Leishmaniasis remains a major public health challenge in many tropical and subtropical regions despite long-standing emphasis on controlling adult sandflies. This commentary highlights an important ecological gap that has received limited attention: the immature stages of sandflies. Unlike mosquitoes, sandflies develop in cryptic terrestrial microhabitats that are rarely detected through routine surveillance. Consequently, most vector control programmes concentrate on suppressing adult populations, while the biological processes that generate new adult vectors remain poorly understood. Recent ecological studies indicate that breeding activity may be spatially structured and biologically detectable. Surveillance approaches that consider oviposition behaviour and breeding ecology may therefore help make vector population dynamics more measurable and support more sustainable, biology-based control strategies.
Trait-based ecology has become central for understanding plant form, function and ecosystem processes, but progress has been hampered by biased representation in trait databases. As such, global trait syntheses remain strongly biased towards temperate forest biomes. Tropical savannas are the most extensive, biodiverse and disturbance-driven ecosystems worldwide, yet are poorly represented in functional trait databases, limiting ecological inference and applied decision-making. Here, we introduce the Cerrado Plant Traits (CPT), an open-access initiative compiling and standardising plant functional trait data for the Brazilian Cerrado, the world's most biodiverse tropical savanna. CPT integrates trait information for all major plant organs (whole-plant, root, shoot, leaf, flower, fruit and seed) across vegetation types in the Cerrado, drawing on a collaborative and inclusive research network. The current version of CPT compiles data from 148 datasets, totalling 113,859 curated trait records for 2,134 taxonomically verified species across 150 families. Trait records span pristine, degraded and restored environments and capture both interspecific and intraspecific variation. Whole-plant and leaf traits dominate the current dataset, while belowground and reproductive traits remain comparatively underrepresented, highlighting key priorities for future research. By substantially increasing the representation of savanna species in global trait repositories, CPT enables tests of ecological hypotheses across multiple levels of organization, analyses of trait-environment relationships across fire, soil and climatic gradients, and robust comparisons across forest-savanna transitions. Beyond its scientific value, CPT provides a practical, standardised resource to support conservation planning, restoration programs and evidence-based policy in a biodiversity hotspot facing accelerating land-use and climate pressures.
Chagas disease is a neglected tropical disease that disproportionately affects underserved populations and is associated with substantial health and socioeconomic burden. Although age-standardised prevalence and mortality have declined since 1990, approximately 10.5 million people remain infected globally. As infected populations age, Chagas disease is increasingly concentrated among older adults and is transitioning from a predominantly acute infection of younger populations into a chronic cardiomyopathy affecting ageing adults in both endemic and non-endemic regions. Migration has further redistributed the disease burden to Western countries where clinical awareness, routine screening, and timely diagnosis of Chagas disease remain limited. We highlight three priorities to address this evolving burden: reframing Chagas disease from a neglected tropical infection to a neglected chronic cardiomyopathy, expanding responsibility of screening and clinical care beyond endemic countries, and strengthening surveillance and epidemiological data systems. Recognising Chagas disease as a chronic cardiovascular condition will be essential for health systems to address its evolving global burden.
The ecological success of modern reef-building corals is rooted in photosymbiosis, yet its macroevolutionary benefit remains unclear. Analyzing the Phanerozoic record of inferred zooxanthellate (Z) and azooxanthellate (AZ) corals over geologic time scales using Bayesian methods, we identify a fundamental shift in diversification dynamics and their drivers across the Paleozoic-Mesozoic transition. Although Z corals dominate modern tropical reef ecosystems, their Paleozoic counterparts were outpaced by AZ forms and showed failed recoveries after the Late Devonian mass extinction. We found Z coral diversification was primarily driven by origination, whereas AZ diversification was controlled by extinction. Multivariate birth-death models reveal that Paleozoic coral diversification was governed by abiotic stressors like warming and anoxia, to which Z and AZ corals showed similar vulnerability. The rise of scleractinian corals in the Triassic marked a distinct macroevolutionary regime shift after which photosymbiosis spurred coral diversification. Positive correlations between temperature and Z coral extinction dominated the Paleozoic, while negative correlations prevailed in the Meso-Cenozoic. The long-term reversal of this relationship could be the reduced supersaturation of the oceans with respect to CaCO3 due to the emergence of calcareous plankton in the Triassic. Our deep-time perspective demonstrates that the advantage of photosymbiosis is not intrinsic but contingent on the broader ecological and environmental context.
Background From mid-June into late December 2025, China experienced its largest-ever Chikungunya virus (CHIKV) outbreak across Guangdong Province, a densely populated region of southeast China with extensive international travel and established Aedes mosquito populations. CHIKV, dengue virus (DENV), and Zika virus (ZIKV) share the same Aedes vectors, overlap in clinical presentation, and exhibit serologic cross-reactivity. We describe the epidemiology and integrated public health response to this outbreak, as well as future arboviral risks and mitigation strategies. Materials and methods We synthesized weekly surveillance data from the Guangdong Provincial Center for Disease Control and Prevention, national epidemiological and genomic data from the China CDC and World Health Organization, Hong Kong Observatory climate records, published literature, and government bulletins. Outbreak dynamics were analyzed using confirmed-case counts disaggregated by prefecture-level city and reporting week. Results Guangdong reported over 25,800 locally transmitted CHIKV cases across all 21 prefecture-level cities, with nationwide cases exceeding 29,500. The outbreak occurred in two distinct waves: an initial wave centered on Foshan City (July-August; 8,948 cases) that was successfully contained through a rapid, multi-level public health response; and a second, larger wave in Jiangmen City (September-October; 10,035 cases) temporally coincident with three tropical cyclones that made landfall within a 16-day span, creating widespread Aedes breeding habitat. No deaths were reported in Guangdong. The causative lineage was the Middle African Lineage within the East/Central/South African genotype, carrying Aedes albopictus-adaptive mutations (E1-A226V, E2-L210Q, E2-I211T) independently acquired through convergent evolution with the Indian Ocean Lineage. The persistence of cases into mid-December, combined with the warmest winter on record in the Pearl River Delta, raises concerns about overwintering mosquitoes and an early resurgence in 2026. Conclusions The 2025 Guangdong outbreak suggests that extreme weather events can overwhelm even well-executed arboviral responses and that the climate-vector-arbovirus interface represents a systems-level vulnerability requiring anticipatory preparedness. We advocate for typhoon-landfall-triggered vector control deployment, intensified genomic and entomological surveillance beginning in spring 2026, multiplex molecular diagnostics for concurrent CHIKV/DENV/ZIKV detection, obstetric and neonatal arboviral screening, and cross-jurisdictional coordination across the Pearl River Delta and beyond.
Urban air pollution, specifically Nitrogen Dioxide (NO2), presents a multifaceted challenge that is intricately coupled with the stochastic, multi-modal, and non-linear dynamics of mega-city traffic systems. This study systematically investigates the non-linear impacts of mixed traffic flow-comprising motorcycles (MC), private cars (PC), and heavy vehicles (BT)-on local air quality at the iconic Bundaran HI intersection in Jakarta, Indonesia. Leveraging a high-resolution, year-long longitudinal dataset, we developed a robust Random Forest (RF) modeling framework integrated with Permutation Importance and Partial Dependence Analysis (PDP) to decipher the environmental footprint of urban transport under tropical conditions. Our results reveal that private car volume and the Volume-to-Capacity (V/C) ratio act as the primary catalysts for NO2 spikes, significantly outweighing the contribution of heavy vehicles in this specific urban corridor. Crucially, a distinct non-linear threshold effect was identified: NO2 concentrations undergo a regime shift, rising exponentially once the V/C ratio exceeds a critical "elbow" of 0.65. This non-linearity indicates that traditional linear mitigation strategies and average-speed-based emission models significantly underestimate pollution risks during saturated traffic states. Policy scenario simulations demonstrate that a 30% reduction in private vehicle volume yields a 5.8% reduction in mean NO2, offering nearly six times the environmental utility of heavy vehicle restrictions. Furthermore, the study explores the role of road surface materials-specifically Stone Mastic Asphalt (SMA)-and meteorological interactions in exacerbating localized pollution. This research provides a data-driven, interpretable framework for urban planners to transition from generic traffic bans toward precision-based, sustainable management strategies that align with the core principles of cleaner production, urban resilience, and UN Sustainable Development Goal 11.
Guava (Psidium guajava L.), a tropical fruit known for its immense benefits, has high perishability, leading to significant post-harvest losses. Drying is important preservation method to extend its shelf life and make it more accessible as a food product. This article comprehensively reviews various drying methods, including traditional (solar and osmotic drying) to modern techniques (spray, freeze, cast-tape, foam-mat microwave-assisted drying, and heat pump drying), their impact on nutrients and composition as well as their key advantages and disadvantages. Spray drying is an efficient method for producing guava powders but faces challenges such as stickiness and nutrient degradation. Freeze-drying preserves most of guava's nutritional and sensory qualities but is cost-intensive. Microwave-assisted drying, is gaining popularity for guava processing due to its rapid drying with minimal nutrient loss. Foam blanket drying utilizing low temperatures produces high-quality porous guava products while retaining essential nutrients and volatile compounds. Heat pump drying is low-cost technique and could be used as alternative preservation technique in food industry. Comprehensive understanding of these drying methods helps choose suitable techniques for industrial use as well as improves product shelf life and consumer appeal.
Phenotypic evolution is shaped by phylogenetic history, ecology and biomechanical constraints. Butterfly wings offer an ideal system to explore these forces, as the relationships between wing morphology and flight characteristics have been intensively studied. Here, we focus on Eudamina skipper butterflies, which display repeated phenotypic convergences of dorsal iridescence and hindwing tails; traits linked to escape ability whose convergence may be driven by predator selection. Using a comprehensive morphometric dataset of 176 species, we assess the evolution of these convergent traits in a phylogenetic framework. We show that hindwing tails and dorsal iridescence have repeatedly evolved in tropical species. Hindwing tails are associated with intermediate body size and forewing shapes that can increase flight manoeuvrability; iridescence is more common in large species with high wing loading and aspect ratio, indicating greater flight speed and manoeuvrability. The evolution of these traits is best described by Ornstein-Uhlenbeck models, consistent with attraction towards trait optima. Further, we reveal co-evolutionary dynamics between fore- and hindwing shapes. Hindwing tails significantly affect forewing shapes in independent lineages, suggesting trade-offs between flight and defence. Together, our results suggest that convergent morphologies in Eudamina likely arose through ecological selection and biomechanical constraints, rather than neutral evolution.
Conventional Water Quality Indices (WQIs) are commonly used to assess anthropogenic impacts on aquatic systems, but they often oversimplify complex parameter interactions, rely on subjective weighting, and inadequately capture spatial or temporal variations. This study hypothesizes that a parameter-based index can enhance diagnostic precision and provide clearer insights into pollutant behavior. The objective was to develop and apply a Parametric WQI that disaggregates water quality into parameter-specific sub-indices for high-resolution monitoring without subjective weighting. Water samples were collected during the peak rainy season from Wupa Sewage Treatment Plant (WSTP), Abuja, Nigeria-covering influent, effluent, the point of discharge (POD), and sites 1-2 km downstream. Thirteen chemical parameters, including nutrients, organic load indicators, and heavy metals, were analyzed. Pollutant levels peaked at the POD but generally declined downstream due to dilution, sedimentation, and microbial degradation. Dissolved Oxygen (DO) increased downstream in June and August but dropped in July (-4.30% at 2 km). TDS rose at the POD in July (+ 16.67%), while TSS fell sharply near the POD (-86.64% in June). Nutrients exhibited strong variability: NH₄⁺ increased (+ 60%), PO₄3⁻ rose sharply (+ 185%), and NO₃⁻ declined (-38.46%), suggesting eutrophication risk. Cu2⁺ spiked (+ 134.17% at POD), whereas Pb2⁺ and Fe2⁺ declined downstream. PWQI classified water quality as poor to very poor at influent, moderate at effluent, and good to excellent downstream. The approach enhances interpretative accuracy, identifies residual contamination (notably NH₄⁺, TSS, and alkalinity), and offers a robust, transferable framework for sustainable wastewater and river system management in tropical environments.
Trypanosoma brucei, a divergent eukaryote parasite, is responsible for neglected tropical diseases in humans and animals, specifically sleeping sickness or human African trypanosomiasis and nagana. Beyond its scientific significance, a comprehensive understanding of its biology has substantial medical and economical implications. Nuclear pore complexes (NPCs) are large multiprotein channels embedded in the nuclear envelope that regulate nucleocytoplasmic transport. In addition to this critical function, NPCs are involved in essential nuclear processes such as chromosome segregation, transcription, and cytokinesis. This study demonstrates that Myosin-like protein-1 (MLP1) localizes to the nuclear basket of NPCs in T. brucei. Silencing of TbMLP1 by RNA interference in T. brucei procyclic cells resulted in severe growth, significant impairment of messenger RNA export, disorganization of nuclear structure, and marked genomic instability. Flow cytometry and fluorescence in situ hybridization (FISH) analyses revealed abnormal DNA content and a reduction in disomic cells, alongside an increase in monosomic, trisomic, and polysomic cells, indicating intolerable aneuploidy detrimental to cell viability. Together, these findings demonstrate that TbMLP1 links NPC function to multiple key cellular pathways. This research provides new insights into the mechanisms that maintain nuclear architecture, preserve nuclear envelope morphology, ensure genome stability, and faithful chromosome segregation, and support appropriat kinetochore distribution and mitotic spindle organization.
The complete mitochondrial genome (mitogenome) of Syndiclis anlungensis, a critically endangered tropical tree, was determined in this study. The mitogenome has a total length of 2,368,454 bp and is composed of four contigs, encoding 41 protein-coding genes, 22 tRNA genes, and three rRNA genes. Potential mutation regions, including 1317 repeat sequences and 698 simple sequence repeats (SSRs), were accurately located in the S. anlungensis mitogenome. Sixty-five transferred fragments of the repeats were found between its mitogenome and plastome. Compared with three other Laurales mitogenomes, extensive gene rearrangements were detected, and only five conserved gene clusters were retained. The codons of mitochondrial and chloroplast genes in S. anlungensis show a strong bias toward A or U(T) endings, and three of these mitochondrial genes-sdh3, rps19, and atp9-exhibit high divergence values among ten Syndiclis species.. The Ka/Ks ratios of rpl2, rpl16, and sdh3 genes were all significantly less than 1, indicating these genes are under strong purifying selection to conserve their functional integrity, with no signatures of positive selection detected. Further phylogenetic analyses were conducted using 41 mitochondrial protein gene sequences from 16 individuals of Syndiclis species and 3 individuals of Beilschmiedia species. Our phylogeny highlights a monophyletic Syndiclis, with two well-supported clades: one clade includes S. anlungensis, S. chinensis, S. lotungensis, S. marlipoensis, and a suspected new Syndiclis species from Yunnan while another clade contains S. furfuracea, S. hongkongensis, S. kwangsiensis, and three suspected new Syndiclis species from Guangdong and Vietnam, respectively.
Transfusion-transmitted malaria can occur when donors have unrecognized asymptomatic infection with submicroscopic parasitemia, highlighting the need to detect low-level parasitemia in blood donor screening. However, these highly sensitive blood donor testing algorithms may refer donors to clinicians who use diagnostic algorithms with less analytical sensitivity. Here we describe the analytical sensitivity of a Health Canada (HC)/FDA approved blood donor screening test compared to commonly used diagnostic test algorithms. The Roche cobas® Malaria NAT performance was assessed. A dilution series of known malaria-positive clinical specimens was prepared (Plasmodium falciparum, P. vivax, and P. ovale) (1:104-107). Percent parasitemia (%parasitemia) via microscopy of clinical samples was used to estimate the infected red blood cells (iRBCs/mL) assuming 5 × 109 RBC/mL. Limit of detection (LoD) at 50% and 95% was calculated. LoDs were compared to currently used Canadian diagnostic methods. Comparison of whole blood and base matrix LoD95 and LoD50 were within 1 log for detection of Plasmodium spp. Overall, Plasmodium spp. LoD50 was 13.3 iRBC/mL and 2.4 × 10-7% parasitemia while LoD95 was 167.1 iRBC/mL and 2.8 × 10-6% parasitemia. LoDs were on average >2 logs lower than other diagnostic tests employed in Canada. Blood operators using highly sensitive donor testing Plasmodium NATs should develop approaches to educate clinicians on characteristics of these tests, as analytical sensitivities may be more sensitive than current diagnostic testing algorithms. Key groups to engage for management of Plasmodium NAT-positive donors include primary care practitioners, infectious diseases physicians, tropical/travel medicine experts, clinical microbiologists, and public health.
This study investigated the hydrogeochemical and isotopic characteristics and irrigation suitability of coastal groundwater on Hainan Island. Forty-eight groundwater and two seawater samples were analyzed using multivariate statistics, graphical methods, and stable isotopes (δ18O, δD). The results showed that coastal groundwater was weakly alkaline, with 83.3% being freshwater and a low degree of seawater intrusion. Hydrochemical types present obvious spatial variability: freshwater is dominated by the HCO₃-Ca·Na type, and saltwater and seawater are of the ClNa type. Atmospheric precipitation is the primary recharge source, with oxygen isotope drift caused by evaporation concentration and salt-freshwater mixing. Deuterium excess gradually declines from mountainous areas to the coast, reflecting spatial variations in groundwater circulation conditions. Water-rock interactions, cation exchange, evaporation concentration, and human activities control the hydrogeochemical evolution of groundwater. Rock salt dissolution is the main source of major ions, and agricultural activities and domestic sewage discharge lead to local enrichment of nitrate. Approximately 62.5% of the groundwater samples were affected by saltwater to varying degrees. In terms of agricultural irrigation, 85% of freshwater and all brackish water are suitable for use, whereas saltwater is unsuitable because of its high sodium and magnesium content. This study provides a scientific basis for the sustainable utilization of groundwater, drinking water safety, and aquatic ecological environment management in Hainan's coastal zone and serves as a reference for hydrogeochemical research on tropical islands worldwide.