Search Results (7,628)

Triplophysa yarkandensis (Cypriniformes: Nemacheilidae), a rare endemic fish in the Tarim River Basin, Xinjiang, China, plays a pivotal role in maintaining the stability of plateau saline–alkaline aquatic ecosystems, yet its survival is increasingly threatened by habitat salinization. However, the multi-dimensional synergistic adaptation mechanisms linking its phenotypic variation, intestinal structure, and associated microbial communities to extreme saline–alkaline stress remain poorly understood. In this study, we innovatively integrated morphological/intestinal histological characterization, 16S rRNA gene sequencing, and microbial ecological analyses (co-occurrence networks and assembly processes) to systematically decode its adaptive strategies. Results revealed that T. yarkandensis exhibits a streamlined body shape, morphological variability, and elongated intestinal villi that may support locomotion and nutrient/ion uptake under osmotic stress. Its gut exerts a stringent selective filter, driving distinct differentiation between water and gut microbial communities—with gut-enriched core taxa (Aurantimicrobium and Aestuariivirga) and functional pathways (unsaturated fatty acid biosynthesis and ABC transporters) specialized for osmoregulation. Notably, the water microbial assembly is dominated by stochastic processes, while the gut assembly relies on host-driven deterministic selection, forming a habitat-specific adaptive pattern. These findings uncover the synergistic adaptation system of host phenotype and gut microbiota for survival in extreme saline–alkaline habitats, advancing our understanding of fish–microbe co-evolution in extreme ecosystems and providing critical theoretical support for the conservation of rare plateau fish, as well as guidance for the utilization of saline–alkaline water resources in aquaculture. Full article

Opisthorchis viverrini infection remains a significant public health concern in Southeast Asia, particularly in rural communities of Northeast Thailand, where persistent environmental and behavioral factors sustain transmission. A quasi-experimental study aimed to identify environmental and behavioral risk factors for infection and to evaluate the effectiveness of a community-based intervention program. The intervention program study was conducted over 10 months and comprised three phases: baseline survey‚ health education intervention program implementation‚ and follow-up evaluation. The results were analyzed for the prevalence of parasitic infections, and multivariable logistic regression was performed to identify associated factors. The majority of study participants were female (67.94%)‚ aged 55 to 64 years (48.09%)‚ and farmers (89.31%). Parasitic infections‚ especially O. viverrini‚ substantially decreased during the follow-up period‚ and independent risk factors predicting infection included lower education‚ previous infection‚ raw fish consumption‚ and pesticide use‚ according to multivariable logistic regression analysis. This intervention considerably improved knowledge; mean knowledge score increased by 6.29 points (p < 0.001). Analysis of fecal sludge after treatment with the sand-drying system identified S. stercoralis larvae (20 eggs/L) and Taenia spp. eggs (12.4 eggs/g). These findings indicated that, despite treatment, integrated behavioral and environmental interventions can be effective in interrupting parasite transmission in rural endemic settings. Full article

Infrared small-target segmentation (IRSTS) is crucial for a wide range of applications, including maritime search-and-rescue operations and intelligent traffic surveillance. However, current deep learning methods struggle with dynamic scale variations in infrared small targets, resulting in false detections and missed detections, alongside inadequate core localization accuracy. To address these challenges, we propose an infrared small-target segmentation framework founded on morphological attention and an energy core loss function, IRSTS_Unet. Specifically, we design a Dynamic Shape-adaptive Deformable Attention Module (DSDAM), which achieves parameterized feature extraction via “initial localization–offset deformation–precise sampling”. This approach enables the network to differentially focus on target cores and background cues to suppress clutter. To improve the efficiency of multi-scale feature aggregation, we embed the DSDAM within both the feature extraction and cross-layer fusion stages. Furthermore, we formulate a Core Energy-aware Core-Priority loss (CECP-Loss) function that incorporates the energy prior distribution of small targets, effectively counteracting the “core dilution” phenomenon endemic to conventional loss functions. Through extensive experiments on multiple public datasets, we demonstrate that IRSTS_U-Net outperforms state-of-the-art approaches in terms of both detection accuracy and robustness. Full article

The seedlings of the young Atlas cedar (Cedrus atlantica Manetti) are very important for the regeneration and restoration of forest populations of this endemic species, which inhabits a very fragmented area in the highest mountains of North Africa (Algeria and Morocco). There is very minimal information on the diseases that are afflicting these young plants. In this work, Alternaria strains CHP2, S4.2, and SP1.1 were isolated from different plants and subjected to identification and pathogenicity testing. The infected plants developed clear symptoms of light brown disease spots on the leaves with a yellowish or chlorotic halo around them, which gradually developed to a yellowing of the plantlets and their complete drying. Some spots merged to form large areas of necrosis which covered an average of 80% of the plantlets. The impact of the infection on plant physiology was determined using measurements of photosynthetic pigments, which showed reductions of 46.28% in chlorophyll and 59.90% in carotenoids in strains SP1.1 and CHP2, respectively. Molecular characterization of the ITS region of the isolates revealed that strains CHP2 and S4.2 showed high sequence similarity to reference sequences of Alternaria spp., including taxa related to A. destruens and A. murispora, although species-level identification remains tentative. These findings highlight the growing relevance of fungal pathogens in forest regeneration under global climate change. By revealing the pathogenic role of Alternaria species, this study contributes to sustainable forest management and conservation strategies in changing environments. Full article

Lysobacter antibioticus Hz25 is a novel strain that was isolated from the rhizosphere of the relict endemic plant Hedysarum zundukii Peschkova (Fabaceae), which grows on carbonate soils in the Baikal region of Russia. This work presents the complete genome sequence of Hz25 (5.98 Mb, 66.94% GC), which was obtained using a hybrid assembly method combining Oxford Nanopore and Illumina sequencing. Phylogenetic analysis based on 47 Lysobacter genomes and an average nucleotide identity (ANI) value of 96% confirmed its affiliation with L. antibioticus. A comparative pan-genome analysis with three closely related strains (13-6, 76, and ATCC 29479) identified 554 strain-specific genes. This significant genomic plasticity likely reflects adaptation to the sharply continental climate, high insolation, and low free iron content of the native soil. The genome encodes a comprehensive micropredator arsenal, including: seven chitinase genes (GH18 and GH19 families); bacteriolytic enzymes (Blp, L1, L4, Ami); a complete type III secretion system (T3SS) with predicted effectors; type IV pili (including the PilZ-PilB regulatory complex); and siderophore biosynthesis genes (lysochelin). The genome contains genes ars of an arsenic resistance system, but lacks the ACR3 efflux pump, suggesting that these genes may have alternative functions. Genes involved in calcium homeostasis (Excalibur domain, Na⁺/Ca²⁺ antiporter) were also identified. These features make Hz25 a promising candidate for biocontrol applications in cold climates and metal-contaminated environments. Full article

This study models trachoma transmission in Cameroon using a deterministic approach with integer and fractional-order derivatives, incorporating direct, fly-mediated, and environmental transmission routes. Fitting disease data from 1990–2019, the model forecasts trachoma prevalence until 2035. The research confirms the solution existence and uniqueness, calculates the basic reproduction number ${\mathcal{R}}_0^{\lambda }$ where $\lambda \in (0,1]$ represents the fractional-order parameter, and analyzes equilibrium stability. A stable trachoma-free equilibrium exists when ${\mathcal{R}}_0^{\lambda }<1$, while an endemic equilibrium is proven stable for ${\mathcal{R}}_0^{\lambda }>1$ under specific conditions. Calibration of a fractional model with Cameroon data yielded an ${\mathcal{R}}_0$ of 1.169 (indicating endemicity) and identified an optimal fractional order of $\lambda =0.98$. By calculating the strength number, we found that another epidemic wave could occur in 50 years. Global sensitivity analysis highlighted key parameters affecting trachoma dynamics. A numerical scheme of the model based on the Adams–Bashforth–Moulton method is constructed and its stability demonstrated. It is then used to perform several numerical simulations, first to validate the theoretical results obtained, and then to compare the different models (statistical and deterministic). The conclusion is reached that the disease will persist in the population (${\mathcal{R}}_0>1$), although the statistical model shows that it could disappear by 2030. This proves that, for trachoma dynamics in Cameroon, it is advisable to use a deterministic model. Full article

River fragmentation caused by dam construction threatens global fish conservation. Mediterranean ecosystems are particularly affected, and the Iberian Peninsula, with its highly fragmented rivers, exemplifies this challenge. Endemic allopatric congeneric barbels (Luciobarbus bocagei and L. sclateri) are particularly vulnerable cyprinids because they rely on river connectivity for migration. Despite the deployment of fishways, their effectiveness in Mediterranean rivers with variable hydrology and high endemism remains unclear. This study compares the passage of L. bocagei (Duero basin) and L. sclateri (Segura basin) across two fishway types: Vertical Slot and Submerged Notch with Bottom Orifice. Passage trials were analysed using standardised metrics, motivation, ascent success, and transit time, under a time-to-event framework. Results suggest that species, size, ecohydrological context, and fishway interact to shape passage outcomes. L. sclateri exhibited higher motivation and faster passage attempts, likely reflecting adaptation to ephemeral flows. Ascent success was similar between species and fishway type. Larger individuals demonstrated greater motivation and shorter transit times, regardless of species or fishway. These findings highlight the importance of integrating ecohydrological context and behavioural variability into fishway assessment. Adaptive management accounting for species- and site-specific traits is essential to enhance connectivity and support endemic populations under growing anthropogenic and climatic pressures. Full article

Introduction: Placental malaria increases the risk of adverse birth outcomes. Current preventive measures are undermined by poor coverage, growing resistance to chemo-preventive and therapeutic drugs, and vector eliminating insecticides. Candidate placental malaria (PM) vaccines (PAMVAC and PRIMVAC) have shown safety and immunogenicity in Phase I trials, but empirical evidence on their potential population-level value is lacking. This study modelled the expected cost-effectiveness of a PM vaccine administered before pregnancy. Methods: A decision-analytic model compared two strategies from the provider’s perspective: vaccinating women of childbearing age versus no vaccination. The model incorporated gravidity-specific risks of PM, neonatal mortality and the malaria attributable fractions from the literature. Since the efficacy of a PM vaccine for malaria prevention is unknown, we assumed a 40% efficacy and varied this estimate widely in sensitivity analyses. Primary outcomes were incremental cost-effectiveness ratios (ICERs) per perinatal disability adjusted life years (DALYs) averted. Baseline, best-case, and worst-case scenarios were analysed. One-way and probabilistic sensitivity analyses were used to assess parameter uncertainty. Cost-effectiveness was defined as an ICER below half of sub- Saharan Africa’s 2025 GDP per capita ($1556). Results: The vaccine was most cost-effective among primigravidae. Under baseline assumptions (40% efficacy; 30% uptake; $5 dose price), the ICER was $321 per perinatal DALY averted for primigravidae versus $4444 for multigravidae. Best-case assumptions further improved cost-effectiveness ($225 vs. $3148). Sensitivity analyses showed robust cost-effectiveness for primigravidae across all plausible parameter ranges, while ICERs in multigravidae were highly sensitive to programme costs and vaccine efficacy. Cost-effectiveness acceptability curves demonstrated that vaccination becomes favourable for primigravidae at relatively low willingness-to-pay thresholds. Conclusions: A placental malaria vaccine delivered before pregnancy has high potential to be cost-effective in endemic areas when targeted to protect primigravidae. These findings support prioritised deployment strategies and highlight the value of early economic modelling to inform vaccine development and policy planning. Full article

Background/Objectives: Tunisia lacks recent national data on hepatitis B virus (HBV) prevalence, particularly following the introduction of universal HBV vaccination in 1995. A national HBV seroprevalence study is essential to guide prevention strategies. This study aimed to estimate the national seroprevalence of HBV infection and identify its determinants 20 years after vaccine introduction. Methods: We conducted a nationwide, household-based, cross-sectional sero-epidemiological survey among a representative sample of the Tunisian general population using a two-stage cluster sampling method. The study was conducted by the National Observatory of New and Emerging Diseases (ONMNE) between December 2014 and June 2015. Data were collected using standardized questionnaires, and blood samples were tested using electrochemiluminescence (ECLIA) to detect HBV biomarkers (HBsAg, anti-HBc, anti-HBs). HBV infection was defined as the presence of HBsAg and/or anti-HBc with the absence of anti-HBs. Associations between HBV infection and explanatory variables (socio-demographics, vaccination status, intrafamilial transmission, and hospital exposures) were assessed using multivariate logistic regression, reporting adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: Among 21,720 participants, 19,155 (88.2%) were tested. The national prevalence of HBsAg was 1.7% (95% CI: 1.55–1.85%), higher among males (2.1%; 95% CI: 1.9–2.4%) than females (1.4%; 95% CI: 1.3–1.6%) (p < 0.001; M/F ratio = 1.48). The mean age of HBsAg-positive participants was 48 ± 15.7 years. Prevalence was highest in the Central (2.3%; 95% CI: 2.0–2.7%) and Southern regions (2.2%; 95% CI: 1.8–2.8%) (p < 0.001). In multivariate analysis, independent risk factors for HBV infection included age >20 years (aOR = 15.10; 95% CI: 4.79–47.64; p < 0.001), having a family member with HBV infection (aOR = 2.82; 95% CI: 2.09–3.79; p < 0.001), residing in the Southern (aOR = 2.51; 95% CI: 1.76–2.71; p < 0.001) or Central region (aOR = 2.18; 95% CI: 1.76–2.71; p < 0.001), male gender (aOR = 1.69; 95% CI: 1.39–2.05; p < 0.001), and hospital follow-up (aOR = 1.23; 95% CI: 1.01–1.51; p = 0.039). HBV vaccination was strongly protective (aOR = 0.36; 95% CI: 0.20–0.62; p < 0.001). Conclusions: The national HBsAg seroprevalence in Tunisia was 1.7%, reflecting a low-endemic status. Vaccination programs should prioritize high-risk groups, including males, adults over 20 years, household contacts of HBV carriers, and residents of the Central and Southern regions. Strengthening infection prevention and control in healthcare settings and adopting intrafamilial precautions among high-risk populations are essential for long-term HBV control. Full article

Intestinal dysbiosis is common in people living with HIV/AIDS (PLWH), yet fungal communities of the gut microbiota (mycobiota) remain poorly characterized, especially in severely immunosuppressed patients. We analyzed the gut mycobiota of 33 PLWH and 20 healthy controls from a public hospital in central Argentina. Most PLWH presented with severe immunosuppression (<200 CD4⁺ T cells/μL) and acute or chronic diarrhea, with or without antibiotic exposure or antiretroviral therapy. Fecal DNA was extracted and the ITS2 region was sequenced using next-generation sequencing. Beta-diversity analyses revealed significant segregation between PLWH and controls (PERMANOVA, Adonis: p = 0.001, R² = 0.0989). LEfSe analysis identified 17 fungal species enriched in PLWH, predominantly Candida albicans, Candida dubliniensis, and Nakaseomyces glabratus, whereas 31 species were differentially represented in controls, including Penicillium spp., Candida sake, and Clavispora lusitaniae. Histoplasma capsulatum, an endemic pathogen in the region, was more prevalent in PLWH and associated with low CD4⁺ T cell counts. Dirichlet multinomial mixture analysis revealed two mycobiotypes: M1, with a balanced fungal composition predominating in controls, and M2, dominated by Candida species and present in PLWH. These findings provide novel insights into gut mycobiota alterations in severely immunosuppressed PLWH in Argentina, highlighting Candida-driven dysbiosis and the regional relevance of H. capsulatum. Full article

Cladocora caespitosa is an endemic hermatypic scleractinian in the Mediterranean Sea, currently threatened by both environmental and anthropogenic pressures, whereas Oculina patagonica is a cryptogenic hermatypic scleractinian that is expanding across the basin. This study provides the first assessment of co-occurring natural populations of these shallow-water taxa, examining their population structures, habitat preferences, and responses to environmental stressors based on SCUBA surveys conducted in the summers and autumns of 2022 and 2023. Both species were dominated by medium- to large-sized colonies, indicating relatively stable population structures, with C. caespitosa exhibiting significantly higher densities than O. patagonica. Both scleractinians showed a preference for sub-vertical and vertical rocky substrates, although O. patagonica appeared more tolerant of horizontal surfaces. Disease events were more frequent and severe in C. caespitosa, particularly affecting larger colonies during autumn 2022, whereas O. patagonica showed lower incidence and greater resilience overall. Temporal comparisons suggest that O. patagonica may act as a strong competitor to C. caespitosa; however, both species demonstrate a considerable capacity for recovery, likely due to adaptation to high-stress environments. These findings highlight key differences in ecological strategies and vulnerability to environmental stressors, emphasizing the need for targeted conservation approaches to preserve Mediterranean shallow-water coral communities under accelerating climate change. Full article

Urbanization threatens amphibians through habitat loss and fragmentation. The critically endangered Hynobius yangi, endemic to Korea, faces severe habitat destruction from urban development. No previous study has simultaneously assessed physicochemical habitat quality and larval feeding ecology across restored and alternative wetlands for this species using fecal DNA metabarcoding. We compared 25 H. yangi spawning sites in Sasong New Town through long-term monitoring (April 2021–September 2024; 364 surveys) and fecal DNA metabarcoding (18S V9, COI313, and blocking primers) from 60 larvae. Egg sac abundance showed negative associations with habitat area (r = −0.21), pH (r = −0.23), and conductivity (r = −0.21); however, none retained significance after Bonferroni correction, and each explained only 4–5% of variance, indicating exploratory associations. Associated conditions included area 115.5 ± 16.2 m² (mean ± SE), circularity 44.2 ± 2.4%, pH 7.55 ± 0.10, and conductivity 53.0 ± 2.7 μS/cm. Dietary analysis identified 17 prey taxa. Larvae in alternative areas showed generalist feeding favoring Perlidae and Tubificidae, while restored-area larvae showed specialist patterns dominated by Chironomidae, Nematocera, and Psychodidae. Both habitat types supported H. yangi populations. These preliminary findings suggest that appropriately designed alternative areas may complement traditional restoration, pending multi-site validation. Full article

Antarctica’s extreme cryospheric conditions impose severe thermodynamic constraints on the natural attenuation of hydrocarbon pollutants. Despite the Antarctic Treaty System’s protections, the footprint of human logistics has left persistent reservoirs of petroleum hydrocarbons that threaten endemic biodiversity. This review critically synthesizes the state-of-the-art in Antarctic bioremediation, moving beyond traditional culture-dependent studies to integrate recent multi-omics breakthroughs (2020–2025). We analyze the molecular mechanisms limiting bioavailability in frozen soils and highlight the adaptive strategies of psychrophilic consortia, including the modification of membrane fluidity and the expression of cold-active enzymes (e.g., RHDs, AlkB). Notably, we discuss emerging findings on novel long-chain alkane degradation genes (almA, ladA) identified in 2025, which challenge previous assumptions about recalcitrance. Furthermore, the review evaluates the engineering bottlenecks of in situ versus ex situ strategies, emphasizing the synergistic potential of bacterial–fungal co-cultures and the ecological necessity of “climate-smart” remediation to mitigate methane emissions from thawing permafrost. By bridging the gap between fundamental microbial genetics and applied field engineering, we propose a roadmap for the next generation of biotechnological solutions in the warming polar environment. Full article

Furuncular myiasis is rarely reported in Southeast/Eastern Europe and may be underrecognized or misdiagnosed in non-endemic settings. We described two imported furuncular myiasis cases diagnosed in Romania following travel to Peru and confirmed the etiologic agent by larval morphology and mitochondrial cytochrome c oxidase subunit I (COI) sequencing. We also conducted a narrative review of published case reports/series from Southeast/Eastern Europe (1900–2025) and summarized case characteristics. A previously healthy 31-year-old woman and 32-year-old man presented with painful furuncle-like lesions on the upper back near the shoulder and the posterolateral upper arm, respectively, associated with pruritus and a sensation of movement. Each lesion had a central punctum with intermittent air bubbles. Occlusion of the breathing pore with petroleum jelly facilitated mechanical extraction of one barrel-shaped larva per lesion. Microscopy showed features consistent with second-instar Dermatobia hominis larvae, and COI sequencing demonstrated 97.14–99.33% identity with reference D. hominis sequences. Literature review identified 25 travel-associated cases, with D. hominis involved mostly after travel to Central/South America. These cases highlight the value of travel history and key diagnostic clues for D. hominis myiasis in travelers that may enable timely diagnosis and minimally invasive management. Greater awareness and reporting are needed to better define epidemiology. Full article

The latest Cretaceous saw the final diversification of dinosaurs before the K/Pg extinction. Discussions of end-Cretaceous dinosaur diversity have focused on well-sampled faunas from Laurasia; far less is known about dinosaurian faunas of the Southern Hemisphere, especially Africa. The late Maastrichtian Phosphates of Morocco provide a rare window into African dinosaur diversity. Abelisaurids, lambeosaurines, and titanosaurian sauropods are known. However, no diagnostic titanosaur remains have been recovered, leaving the affinities of these sauropods unclear. We describe Phosphatotitan khouribgaensis gen. et sp. nov., a new titanosaur from the Maastrichtian of Sidi Chennane, Khouribga Province. Phosphatotitan is represented by dorsal, sacral, and caudal vertebrae, and the pelvis. The new species differs from titanosaurs described from the Cretaceous of Africa and Europe but resembles South American Lognkosauria, and especially Patagotitan, in having short dorsal and caudal centra, expanded dorsal and caudal neural spines, and a broad pubis. Its small size relative to other Lognkosauria (3.5–4 tonnes) suggests a lineage selected for small size. The close relationships of Morocco’s titanosaurs and abelisaurids to South American species may reflect a wide distribution of these clades prior to the opening of the South Atlantic and the separation of Africa and South America ~100 Ma, while a complex pattern of oceanic dispersal may explain the presence of distinct saltasauroid lineages worldwide. The latest Cretaceous Gondwanan dinosaur faunas were highly endemic due to a combination of continental fragmentation, extinction, and dispersal, creating high endemism in southern continents and within Africa, suggesting that Maastrichtian dinosaur diversity is underestimated. Full article