Search Results (215)

The Marburg virus (MARV) is a zoonotic pathogen that causes a high case fatality rate of up to 100% in humans. In response to Marburg virus disease (MVD) outbreaks in the Kagera region, an ecological investigation was initiated to map the population and ecological threat to the reservoir host of MARV: Egyptian fruit bats. The investigation conducted from October 2023 to December 2024 included interviews with local authorities to locate all known autochthonous bat colonies in the region. Bat species confirmation was performed using high-resolution melting analysis (HRMA) and DNA barcoding, targeting two mitochondrial genes: cytochrome oxidase 1 (COI) and 16S rRNA. We found five considerably large cave-dwelling Egyptian fruit bat colonies (with approximately 100,000 individuals) at the geolocations between 1°06′04.2″ and 2°26′35.8″ S latitude and 30°40′49.7″ and 31°51′19.8″ E longitude. The study also provides the first confirmed identification of Egyptian fruit bats (Rousettus aegyptiacus) (accession numbers: PV700530-PV700534) in major bat colonies in the Kagera River Basin ecosystem. Cave-dwelling Egyptian fruit bats in mines face higher risks, and thus, attention is needed to prevent this species from becoming more vulnerable to extinction. The loss of bat roosting sites and subsequent population declines are primarily driven by the destructive practice of burning car tyres and logs, a method used to eliminate colonies through toxic smoke and heat. The collection of guano and partially eaten fruits in mining caves, as well as daily contact with Egyptian fruit bats in mines, homes, and churches, have become major potential risk factors for MARV transmission to humans. Increased threats to bats in the Kagera region warrant the implementation of conservation strategies that ensure the survival of the bat populations and inform policies on MVD risk reduction in Tanzania and the broader East African region. Full article

Many countries around the world feature raw fish in their cuisine, which is valued for its unique flavor. However, raw fish may be easily contaminated with foodborne pathogens including Listeria monocytogenes, Salmonella, Vibrio parahaemolyticus, and Staphylococcus aureus. Herein, a method was established that integrated a multiplex polymerase chain reaction (PCR) and high-resolution melting (HRM) curve assay for the simultaneous detection of these four foodborne pathogens. The target genes of the bacteria were amplified by PCR and subsequently analyzed using HRM. Differentiation was achieved based on the melting temperature (Tm) values of their respective amplicons. The detection limit of the PCR-HRM assay was 0.02–0.1 ng/µL. In addition, the Tm remained nearly constant across various concentrations of genomic DNA derived from the target bacteria. The assay demonstrated perfect specificity (8/8) and a sensitivity of 5/5 for L. monocytogenes, 2/2 for Salmonella, 3/3 for V. parahaemolyticus, and 3/3 for S. aureus. No significant interference occurred when genomic DNA from the four target bacteria was co-extracted with DNA from eight non-target strains. Furthermore, the assay offers advantages including operational simplicity, high efficiency, accurate results, reduced detection time, and lower costs, rendering it well-suited for food safety applications in the aquatic products processing industry. Full article

Extensive radar investigations, observed spectral signatures, geomorphological, and paleoclimate modeling support the presence of mid- to low-latitude ground ice on Mars. The presence of near-surface ice and glacial features has been proposed in Ismenius Lacus, but the ice composition and age remain unconstrained. Our high-resolution stereoscopic analysis reveals distinctive landforms, including sharp-edged polyhedra, chevron patterns, and en-echelon open fractures, indicative of plastic glacial deformation. Current climatic conditions may support year-round ice stability, while sharp-edged polyhedra, open fractures, and the absence of superposed craters suggest active glaciation. The Ariguani delta system lacks fluvial signatures but aligns with glacial erosional and depositional processes. Unlike terrestrial glaciers, ice accumulation here is likely driven by escarpment-fed melt from seasonal permafrost thawing under lithostatic pressure, generating neo-glacial flows that sustain the glacial tongue. This mechanism can also explain regional features, including U-shaped valley subsidence, gravitational slides, flow of low-viscosity material lobes, and ring-mold craters. Thus, we propose sharp-edged polyhedra as diagnostic markers for identifying ongoing ice dynamics on Mars, enabling future automated detection of active glacial environments. Full article

Palm lethal yellowing phytoplasmas (PLYPs) are a group of phytoplasmas that cause death in infected hosts across the tropics. Historically, detection and identification has relied on standard PCR, nested PCR, and restriction fragment length polymorphism. While these approaches are generally good, they are prone to error and contamination that is significantly lower or absent in modern approaches using quantitative PCR (qPCR) and digital PCR (dPCR). Additionally, these modern approaches are more time-efficient and consume fewer resources, making them more cost-effective in the long term. Recent studies have adapted dPCR and qPCR coupled with high-resolution melt curve analysis (HRMA) for PLYPs in the Caribbean/New World; however, these tools have not been developed for phytoplasmas in Africa and Madagascar. In this study, a duplex dPCR assay was developed with two specific assays, one for ‘Candidatus Phytoplasma palmicola’ and one for ‘Ca. P. cocostanzaniae’ and isolates from Madagascar. Additionally, primers targeting the secA gene were optimized and allowed for the separation of ‘Ca. P. cocostanzaniae’ and Malagasy isolates by approximately one degree Celsius. New primers were developed based on secA for ‘Ca. P. palmicola’ that allowed for the separation of the two subgroups (A and B) by HRMA by a difference of approximately one degree Celsius. These assays provide a valuable resource to explore aspects such as vector discovery and host range. Full article

Background/Objectives: Alport syndrome (AS) predominantly presents with X-linked inheritance worldwide. However, the epidemiological landscape remains poorly characterized, particularly among ethnic minority groups like the Roma minority in Slovakia. Our study aimed to investigate the inheritance patterns of AS in this region and determine whether a distinct pattern predominates. Methods: Selective genetic screening for pathogenic variants previously occurring in Slovakia was performed. Samples from patients with persistent (familial) hematuria ± hearing loss who had not yet undergone biopsy or genetic testing were analyzed by high-resolution melting analysis. The prevalence of AS per million (pm) population was calculated by adding information on patients with previously confirmed AS. Results: Twenty-five new cases of ARAS, one digenic form, and two cases of XLAS were identified by screening. In total, we collected information on 46 patients with genetically or bioptically confirmed AS in the region of eastern Slovakia, corresponding to a prevalence of 29 pm population. The c.1598G>A (p.Gly533Asp) pathogenic variant of the collagen type IV alpha 4 chain, which follows an autosomal recessive inheritance pattern, was the most prevalent variant that was exclusively confirmed in Roma patients (n = 35), suggesting a founder effect. Within the Roma community, the prevalence of ARAS (the most prevalent inheritance pattern) corresponds to 133 pm of the Roma population, based on midpoint population estimates. Conclusions: Our findings demonstrate a unique genetic profile of AS in the Roma population, characterized by a high prevalence of ARAS, with implications for genetic counseling and screening strategies. Full article

Background/Objectives: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder with a multifactorial pathogenesis and a well-established genetic component. While pathogenic variants in genes such as ABCB4 and ABCB11 are implicated in a subset of cases, many remain genetically unexplained. This study aimed to investigate the genetic background of ICP in a multi-generational family with recurrent hepatobiliary disease. Methods: Whole-exome sequencing was performed on the proband and five female relatives. Variant filtering prioritized rare, exonic or splice-site variants predicted to undergo damage by in silico tools and which were present in all affected family members. Identified variants were assessed using population databases and compared with a control group of 433 unrelated women with uncomplicated pregnancies. Variant confirmation was performed using Sanger sequencing and high-resolution melting analysis. Results: No pathogenic variants were identified in known ICP-associated genes. However, a rare heterozygous missense variant in ABCB5 (c.1610G>A; p.Arg537His; rs779950110) was found in all affected individuals and two younger female relatives. This variant is exceedingly rare in population databases, absent in controls, and predicted to be pathogenic by multiple algorithms. ABCB5, although not previously linked to ICP, is an ATP-binding cassette transporter expressed in various tissues, including liver compartments. Conclusions: This study reports a novel ABCB5 variant segregating with ICP and early-onset hepatobiliary disease in a family. These findings suggest ABCB5 as a potential new susceptibility gene in ICP, warranting further functional investigation. Full article

Effective species identification is crucial for the conservation and management of marine mammals, particularly in regions such as the Mediterranean Sea, where several cetacean populations are endangered or vulnerable. In this study, we developed and validated a High-Resolution Melting (HRM) analysis protocol for the rapid, cost-effective, and reliable identification of the four representative marine cetacean species that occur in the Mediterranean Sea: the bottlenose dolphin (Tursiops truncatus), the striped dolphin (Stenella coeruleoalba), the sperm whale (Physeter macrocephalus), and the fin whale (Balaenoptera physalus). Species-specific primers targeting mitochondrial DNA regions (cytochrome b and D-loop) were designed to generate distinct melting profiles. The protocol was tested on both tissue and fecal samples, demonstrating high sensitivity, reproducibility, and discrimination power. The results confirmed the robustness of the method, with melting curve profiles clearly distinguishing the target species and achieving a success rate > 95% in identifying unknown samples. The use of HRM offers several advantages over traditional sequencing methods, including reduced cost, speed, portability, and suitability for degraded samples, such as those from the stranded individuals. This approach provides a valuable tool for non-invasive genetic surveys and real-time species monitoring, contributing to more effective conservation strategies for cetaceans and enforcement of regulations against illegal trade. Full article

The Citrus tristeza virus (CTV), a member of the Closterovirus genus, is considered a serious threat to citrus trees grafted onto sour orange (SO) rootstock. In the Mediterranean area, the most prevalent CTV strains are VT and T30. The VT strain includes both mild and severe isolates, some of them associated with seedling yellows (SY) syndrome. Mild CTV-VT isolates that do not induce SY symptoms (no-SY) show minor variations in their Orf1a, p23, and p33 genes, with a single nucleotide polymorphism at position 161 of the p23 gene. These isolates can repress superinfection with homologous severe isolates. The aim of this study was to investigate the mechanism of cross-protection by means of biological indexing, real-time RT-PCR high-resolution melting (HRM), and p23 gene amplicon sequencing. Four no-SY CTV-VT isolates were inoculated onto SO seedlings and Hamlin sweet orange trees grafted on SO. These plants were later challenged with two homologous CTV-VT SY isolates and remained asymptomatic. The biological evaluation of the infection process in superinfected plants was investigated via inoculation of the bark on SO seedlings that were also asymptomatic. A parallel HRM analysis of midvein RNA extracts revealed that the melting temperature (Tm) of the no-SY isolates was statistically lower than that of the SY isolates. The Tm values of RNAs extracts from superinfected plants were not statistically different from those of the no-SY isolates. This suggests that the SY isolates failed to establish infection or replicate in plants pre-inoculated with no-SY isolates. This blockage of replication resembles superinfection exclusion, with attractive perspectives to prevent SY damage in field applications. Full article

Snow cover phenology (SCP) serves as a critical regulator of hydrological cycles and ecosystem stability across the Mongolian Plateau (MP). Despite its importance, the spatiotemporal patterns of SCP and their climatic drivers remain poorly quantified, constrained by persistent gaps in satellite snow cover observations. Leveraging a high-resolution (500 m) daily gap-filled Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover dataset combined with reanalysis climate datasets, we systematically quantified SCP dynamics and identified the dominant controls during the 2000–2022 hydrological years using trend analysis and ridge regression. Our results reveal a significant divergence in SCP parameters: snow end dates (D_e) advanced markedly across the entire plateau (0.29 days yr⁻¹, p < 0.01), accounting for 90.39% of SCP anomalies. In contrast, snow onset date (D_o) exhibited unnoticeable changes, explaining 9.58% of SCP changes. Attribution analysis demonstrates that 47.72% of D_e variability stems from increased net shortwave radiation (+0.38 Wm⁻² yr⁻¹) and rising temperatures (+0.06 °C yr⁻¹) during the melting season, with net shortwave radiation exerting stronger control (R² = 0.73) than temperature (R² = 0.63). This study establishes the first continuous, high-resolution SCP climatology for the MP, providing mechanistic insights into cryosphere–atmosphere interactions that inform adaptive water resource strategies for climate-vulnerable arid ecosystems in this region. Full article

The rapid progress in additive manufacturing (AM) has unlocked significant possibilities for producing 316/316L stainless steel components, particularly in industries requiring high precision, enhanced mechanical properties, and intricate geometries. However, the widespread adoption of AM—specifically Directed energy deposition (DED), selective laser melting (SLM), and electron beam melting (EBM) remains challenged by inherent process-related defects such as residual stresses, porosity, anisotropy, and surface roughness. This review critically examines these AM techniques, focusing on optimizing key manufacturing parameters, mitigating defects, and implementing effective post-processing treatments. This review highlights how process parameters including laser power, energy density, scanning strategy, layer thickness, build orientation, and preheating conditions directly affect microstructural evolution, mechanical properties, and defect formation in AM-fabricated 316/316L stainless steel. Comparative analysis reveals that SLM excels in achieving refined microstructures and high precision, although it is prone to residual stress accumulation and porosity. DED, on the other hand, offers flexibility for large-scale manufacturing but struggles with surface finish and mechanical property consistency. EBM effectively reduces thermal-induced residual stresses due to its sustained high preheating temperatures (typically maintained between 700 °C and 850 °C throughout the build process) and vacuum environment, but it faces limitations related to resolution, cost-effectiveness, and material applicability. Additionally, this review aligns AM techniques with specific defect reduction strategies, emphasizing the importance of post-processing methods such as heat treatment and hot isostatic pressing (HIP). These approaches enhance structural integrity by refining microstructure, reducing residual stresses, and minimizing porosity. By providing a comprehensive framework that connects AM techniques optimization strategies, this review serves as a valuable resource for academic and industry professionals. It underscores the necessity of process standardization and real-time monitoring to improve the reliability and consistency of AM-produced 316/316L stainless steel components. A targeted approach to these challenges will be crucial in advancing AM technologies to meet the stringent performance requirements of various high-value industrial applications. Full article

The main constituent of the planetary lithosphere is the dominant silicate mineral, olivine α-(Mg,Fe)₂SiO₄, which, along with associated minerals and the olivine-hosted inclusions, records the physical–chemical conditions during the crystal growth and transport to the planetary surface. However, there is a lack of physical–chemical information regarding the kinetic factors that regulate crystal growth during melt–rock, fluid–rock, and magma–rock interactions. Here, we conducted an experimental reaction between hydrated peridotite rock and basaltic melt and coupled this with a structural and elemental analysis of the quenched products by high-resolution transmission electron microscopy. The quenched products revealed crystallographically oriented oxide nanocrystals of ilmenite (Fe,Mg)(Ti,Si)O₃ that grew over the newly formed olivine in the boundary layer melt of the reaction zone. We established that the growth mechanism is epitaxial and is common to both experimental and natural systems. The kinetic model developed for shallow (<1 GPa) crystal growth requires open system conditions and the presence of melt or fluid. It implies that the current geodynamic models that consider natural ilmenite–olivine assemblage as a proxy for deep to ultra-deep (>>1 GPa) conditions should be revised. The resulting kinetic model has a wide range of geological implications—from disequilibrium mineral growth and olivine-hosted inclusion production to mantle metasomatism—and helps to clarify how geological reactions proceed at depth. Full article

Background: In recent years, numerous recurrently mutated genes have been identified in acute myeloid leukemia (AML), some of which, such as FLT3 and IDH1/2, serve as therapeutic targets, offering new treatment options. Rapid mutational analysis is crucial for timely and optimal therapy selection. This study aims to develop and validate a rapid, cost-effective, and sensitive screening method for detecting IDH1, IDH2, and FLT3-TKD2 mutations using polymerase chain reaction (PCR) and high-resolution melting curve analysis (HRM). Methods: A PCR-HRM assay was developed to simultaneously detect mutations in IDH1, IDH2, and FLT3-TKD2. The method was applied to a cohort of 1363 AML patients, and its performance, including turnaround time, was evaluated through comparison with next-generation sequencing (NGS) results. Results: The PCR-HRM method demonstrated a positive percent agreement of 98%, 98%, and 92% for IDH1, IDH2, and FLT3-TKD2, respectively, and a negative percent agreement of 100% for all three genes compared to NGS. No false positives were observed, and false negatives were detected in less than 1% of cases, mostly in FLT3-TKD2, all occurring below the established limit of detection. The turnaround time and cost of PCR-HRM were significantly lower than those of NGS. Conclusions: This method offers a highly sensitive, specific, and time-efficient approach for the simultaneous detection of IDH1, IDH2, and FLT3-TKD2 mutations in AML patients. Its rapid turnaround time and cost-effectiveness make it a valuable tool for routine clinical screening, facilitating timely and targeted treatment decisions. Full article

Snow water equivalent (SWE), the amount of water generated when a snowpack melts, has been used to study the impacts of climate change on the cryosphere processes and snow cover dynamics during the winter season. In most analyses, high-temporal-resolution SWE and SD data are aggregated into monthly and yearly averages to detect and characterize changes. Aggregating snow measurements, however, can magnify the modifiable aerial unit problem, resulting in differing snow trends at different temporal resolutions. Time series analysis of gridded SWE data holds the potential to unravel the impacts of climate change and global warming on daily, weekly, and monthly changes in snow during the winter season. Consequently, this research presents a high-temporal-resolution analysis of changes in the SWE across the cold regions of Canada. A Siamese UNet (Si-UNet) was developed by modifying the model’s last layer to incorporate the structural similarity (SSIM) index. The similarity values from the SSIM index are passed to a contrastive loss function, where the optimization process maximizes SSIM index values for pairs of similar SWE images and minimizes the values for pairs of dissimilar SWE images. A comparison of different model architectures, loss functions, and similarity metrics revealed that the SSIM index and the contrastive loss improved the Si-UNet’s accuracy by 16%. Using our Si-UNet, we found that interannual SWE declined steadily from 1979 to 2018, with March being the month in which the most significant changes occurred (R² = 0.1, p-value < 0.05). We conclude with a discussion on the implications of the findings from our study of snow dynamics and climate variables using gridded SWE data, computer vision metrics, and fully convolutional deep neural networks. Full article

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underwent significant mutations, resulting in the Omicron variant. Methods: In this study, we analyzed blood samples from 98 patients with acute coronavirus disease 19 (COVID-19) hospitalized during the initial SARS-CoV-2 wave and the onset of Omicron in 2021. High-resolution melting (HRM) analysis of PCR products was used to analyze RNA extracted from clinical samples collected in July and November 2021 from patients infected with SARS-CoV-2. Results: HRM analysis revealed a characteristic deletion in the N protein RNA of the virus isolated in November 2021, associated with the Omicron variant. Elevated levels of inflammatory markers and interleukin-6 (IL-6) were observed in both waves of COVID-19. Complement levels and IgG and IgM antibodies to SARS-CoV-2 were detected more often during the second wave. An increase in hemagglutinin-inhibiting (HI) antibodies against influenza viruses was observed in paired blood specimens from moderate to severe COVID-19 patients during both outbreaks. Conclusions: Patients admitted during both waves of COVID-19 showed a significant rise in inflammatory markers, suggesting that Omicron triggers inflammatory responses. The rapid formation of IgM and IgG in Omicron may indicate a faster immune response. Seasonal flu may negatively impact the clinical course of coronavirus infections. Full article

Addressing the pervasive issue of food adulteration and fraud driven by economic interests has long presented a complex challenge. Such adulteration not only compromises the safety of the food supply chain and destabilizes the market economy but also poses significant risks to public health. Food adulteration encompasses practices such as substitution, process manipulation, mislabeling, the introduction of undeclared ingredients, and the adulteration of genetically modified foods. Given the diverse range of deceptive methods employed, genomics-based identification techniques have increasingly been utilized for detecting food adulteration. Compared to traditional detection methods, technologies such as polymerase chain reaction (PCR), next-generation sequencing (NGS), high-resolution melt (HRM) analysis, DNA barcoding, and the CRISPR–Cas system have demonstrated efficacy in accurately and sensitively detecting even trace amounts of adulterants. This paper provides an overview of genomics-based approaches for identifying food adulteration, summarizes the latest applications in certification procedures, discusses current limitations, and explores potential future trends, thereby offering new insights to enhance the control of food quality and contributing to the development of more robust regulatory frameworks and food safety policies. Full article