Search Results (231)

This work demonstrates laser-induced breakdown spectroscopy (LIBS) applied to a stream of aerosolized salt from molten eutectic LiCl-KCl. We demonstrate analytical capabilities to track fission-product surrogates of Cs, Sr, Pr, and Nd simultaneously, with application to monitor salts in pyroprocessing schemes and molten salt reactors. This work demonstrates limits of detection using LIBS on the order of 100 $\mathsf{\mu }$g/g, which proves potentially applicable to monitoring fission-product concentrations in pyroprocessing applications. Additionally, this work explores fundamental aspects of plasma temperature and plasma electron density of the aerosolized species during LIBS with a specific focus on potential non-uniform plasma conditions in the aerosol. Full article

Obtaining reliable estimates of population sizes and their temporal trends is essential for assessing the conservation status and guiding the management of threatened species. Parrots (order Psittaciformes) are among the most diverse yet most threatened groups of birds worldwide, but information on their population sizes remains scarce. Their ecological traits and low densities complicate the application of widely used distance sampling methods for estimating population densities, which correct for declining detectability with increasing distance. Researchers have proposed simple encounter rates—the number of birds or groups detected per hour of observation during casual walks—as an alternative approach to address these limitations when estimating the abundance of rare species. Previous studies of the globally endangered African grey parrot (Psittacus erithacus) demonstrated that encounter rates derived from walk transects serve as reliable surrogates for densities estimated using distance sampling models. In this study, we evaluated whether car surveys and point counts, two other commonly used methods for estimating bird abundance, produce encounter rates comparable to those obtained from walk transects, thereby allowing greater methodological flexibility. To this end, we conducted a nationwide survey of African grey parrots in Equatorial Guinea using walk transects, car transects, and point counts (199 surveys, 1973 km, 192 h), which yielded 1166 encounters and 2972 recorded individuals. Three aspects of parrot detectability (the frequency of aural and visual detections, whether birds were perched or in flight, and detection distances) did not differ among the three survey methods. Encounter rates and the number of individuals observed per hour varied among sampled regions but did not differ among survey methods. These findings support the use of the three methods, either individually or in combination, to estimate the abundance of this globally endangered species and provide a basis for testing and applying this approach to other parrot species and geographic regions. Full article

Conservatively perturbed equilibrium (CPE) experiments yield transient concentration extrema that surpass steady-state equilibrium values. A physics-informed neural network (PINN) framework is introduced to simulate these over-equilibrium dynamics in linear chemical reaction networks without reliance on extensive time-series data. The PINN incorporates the reaction kinetics, stoichiometric invariants, and equilibrium constraints directly into its loss function, ensuring that the learned solution strictly satisfies physical conservation laws. Applied to three- and four-species reversible mechanisms (both acyclic and cyclic), the PINN surrogate matches conventional ODE integration results, reproducing the characteristic early concentration extrema (maxima or minima) in unperturbed species and the subsequent relaxation to equilibrium. It captures the timing and magnitude of these extrema with high accuracy while inherently preserving total mass. Through the physics-informed approach, the model achieves accurate results with minimal data and a compact network architecture, highlighting its parameter efficiency. Full article

Germ cell xenotransplantation is a promising tool for enhancing aquaculture production and supporting the conservation of declining fish species. A major limitation is the reliable identification of germ stem cells, which remains challenging due to the scarcity of validated molecular markers. This study assessed the suitability of different immunohistochemical approaches for identifying ovarian germ stem cells (OGSCs) in three Mediterranean species of commercial interest: European hake (Merluccius merluccius), meagre (Argyrosomus regius), and flathead grey mullet (Mugil cephalus). Among the antibodies tested (anti-OCT4, anti-VASA, anti-Sox2), only anti-VASA and anti-Sox2 labeled cells with morphological features consistent with OGSCs, although staining intensity, specificity, and cross-reactivity with early oocytes varied across species. In parallel, preliminary protocols for OGSC isolation and in vitro proliferation were developed for European hake and meagre. Enzymatic dissociation with collagenase, followed by Ficoll-Paque density separation and culture in Leibovitz’s L-15 medium supplemented with 2% fetal bovine serum at 25 °C, resulted in the highest OGSC recovery and detectable increases in proliferating cells. A sequential pre-plating step enhanced enrichment in meagre but caused substantial cell loss in hake. Overall, this study provides a comparative evaluation of female germline stem cell markers in these species, contributing to future surrogate reproduction and germplasm conservation strategies. Full article

A fiber-optic visible–near-infrared absorption spectroscopy system in a glove box was demonstrated for remote quantification of Am(III) (0–500 µM) and HNO₃ (0.1–9 M) using partial least squares regression (PLSR) models. The sensor platform, featuring a simple plug-and-play spectrophotometer, can enable noninvasive, real-time monitoring of actinide process solutions. To establish a flexible PLSR model calibration strategy, a D-optimal design developed using Nd(III) in previous studies was successfully extended to an actinide system with Am(III) to effectively minimize sample set size while maintaining robust prediction performance. The results suggest strong spectral similarities between Nd(III) and Am(III) and validate Nd(III) as an effective optical surrogate for trivalent actinide species. This work also supports the generalizability of a D-optimal training set selection approach for two-factor systems. The PLS1 models for Am(III) and HNO₃ outperformed a PLS2 model and maintained reasonable performance in the presence of interfering U(VI). The resulting sensor system and multivariate approach provides a flexible and scalable solution for process monitoring, control, and safety in diverse nuclear applications. Full article

Since its discovery in 2019, SARS-CoV-2 has continued to be detected in both humans and animals worldwide. Currently there is limited research focusing on serological surveillance of wildlife under human care. Here we tested 230 serum samples of 134 animals from two zoological institutions collected between 2015 and 2024. To assess prior exposure and antibody responses from natural infection or vaccination, we used three serological assays: a nucleocapsid protein-based ELISA (N-ELISA), a surrogate virus neutralization test (sVNT) for spike (S) protein and a neutralization assay with S-pseudotyped viral particles. Among the 114 samples collected from 58 animals at Fort Wayne Zoo in Indiana, 37 samples from 20 vaccinated animals were sVNT-positive, and 2 of the positive animals had 2 samples prior to vaccination that tested positive by N-ELISA. Of the 116 samples from 76 animals at Brookfield Zoo in Illinois, 20 samples of 20 animals were sVNT-positive, and 19 of the positive animals had been vaccinated. Among these 20 sVNT-positive samples, only one sample from a South American Tapir was positive from prior to vaccination and 1 sample from a sloth bear was also positive by N-ELISA, marking the first documented cases of SARS-CoV-2 exposure in both species. Neutralization assays with S-pseudotyped virus revealed that some of the sVNT-positive samples have strong activity against the WH1-S pseudovirus but showed significantly reduced neutralization against the Omicron LP.8.1-S pseudovirus. These results underscore the need for updated vaccines tailored to emerging variants. Overall, our findings highlight the importance of continued serological surveillance across multiple species to detect new SARS-CoV-2 exposures and monitor vaccine-induced immunity in captive animal populations. Full article

Phytoindication represents a long-established ecological approach; however, its conceptual basis remains contested, particularly concerning whether it is merely a surrogate for measuring environmental factors or a distinct method for assessing biotic system responses. In this study, we analysed vegetation communities of the sandy terrace in the Dnipro-Oril Nature Reserve (Ukraine) using ecological indicator values, naturalness, and hemeroby indices. The Dnipro-Oril Nature Reserve provides an ideal setting for this study, as it integrates strong natural gradients of soil moisture, nutrient availability, and topography with pronounced anthropogenic influences from the surrounding industrial landscape. This allows the assessment of both natural and human-driven components of ecological variability within a single system. A dataset of 1079 relevés was collected and classified into 24 associations. Multivariate analyses were applied to reveal different aspects of vegetation–environment relationships: MANOVA was used to assess whether plant associations differed significantly in their ecological indicator profiles, CCA to identify the main gradients of species composition constrained by environmental factors, and partial CCA to isolate the specific patterns of vegetation response attributable to individual predictors while controlling for covariates. We found that the indicator values were not independent but strongly intercorrelated, reflecting integrated biotic responses rather than methodological artefacts. This was confirmed by consistent ecological interpretation of the principal component structure and the concordance between ordination patterns and vegetation classification results. Two primary gradients were identified: a natural gradient, which combines soil moisture and nutrient availability with decreasing light, temperature, continentality, and soil pH; and an anthropogenic gradient, represented by the hemeroby–naturalness axis. The interplay of these gradients offers a comprehensive explanation for vegetation structure across various spatial scales, with natural factors shaping community types and anthropogenic influences exerting broader, less specific effects due to their diffuse impact across multiple plant associations. Our findings reveal a novel conceptual perspective, supporting the view that phytoindication is a unique ecological tool for assessing the integrated response of plant communities to environmental drivers, including both natural and anthropogenic gradients, rather than a simplified or less precise substitute for instrumental measurements. Nevertheless, the use of phytoindication does not eliminate the need for instrumental measurements in situations requiring precise quantification of specific physical or chemical environmental parameters. The correlated structure of indicator values revealed in this study demonstrates that phytoindication patterns are specific to each landscape. Therefore, comparative assessments across regions or time periods should be based on the correlation patterns of indicator values rather than their absolute scores. Full article

This study addresses a critical challenge in global conservation: understanding how rare species contribute to ecosystem structure and resilience. The ecological role of the endangered black-and-white snub-nosed monkey in China’s temperate mountain forests was examined, with the hypothesis that its tree-shaking behavior alters forest structure and microclimates to enhance ecosystem health. To assess long-term impacts, current monkey-inhabited forests were compared with historical sites abandoned over decades, by analyzing tree gaps, forest structure, and environmental conditions. Monkeys’ canopy-disturbing actions were also directly observed. Findings revealed monkey activity created more canopy gaps (38.3% in current habitats vs. 29.9~33.5% in abandoned sites) and altered microclimate conditions, which boosted plant diversity and optimized the community’s vertical and age structures. Current forests supported nearly twice as many tree species, 2.5 times as many shrub species, and threefold more herb species than areas abandoned for 40 years. Even 20 years after monkeys disappeared, abandoned sites retained higher diversity and gaps, showing lasting ecological benefits. These results confirm the monkey’s vital role as a resilience promoter, demonstrating how rare species can shape healthier ecosystems. This highlights the need to prioritize protecting such species, as their survival not only preserves biodiversity but also sustains ecosystem functions crucial for human well-being. Full article

Background/Objectives: In this proof-of-concept study, the objective was to evaluate the phenotypic CarbaLux combination rapid test in terms of guiding the therapy of infections caused by multidrug-resistant Gram-negative bacteria with carbapenemase inhibitors and carbapenems, and to compare its results and practicability with standard diagnostic methods. Methods: In the classical CarbaLux test, a fluorescent carbapenem serves as a UV–visible diagnostic surrogate for clinically used carbapenem antibiotics. When exposed to extracted carbapenemases from bacterial colony growth on agar plates, fluorescence rapidly disappears, showing whether monotherapy with carbapenems is possible or must be rejected. It was expected that a specific inhibitor that protects imipenem or meropenem from enzymatic deactivation during antibacterial therapy would perform the same in vitro with fluorescent carbapenem and preserve its fluorescence. The new additional CarbaLux combination test is used if the classic test is positive for carbapenemases: a classic test tube pre-dosed with fluorescent carbapenem is spiked with cloxacillin; with recently launched carbapenemase inhibitors, e.g., avibactam, relebactam, zidebactam, nacubactam, or vaborbactam; or with picolinic acid. Fourteen Enterobacterales and six Acinetobacter baumannii isolates were analyzed. Results: At fixed concentrations, the new inhibitors protected fluorescent carbapenem from bacterial KPC-mediated inactivation and partially from AmpC beta-lactamase-mediated inactivation. In addition, avibactam also effectively inhibited OXA-48-like enzymes. Cloxacillin selectively inhibited AmpC beta-lactamases extracted from Enterobacter complex species. Non-therapeutic picolinic acid was specific for metallo-beta-lactamases and thus identified infections by pathogens that cannot be treated with carbapenems alone or in combination. Conclusions: Inhibitor/fluorescent carbapenem mixtures corresponding to therapeutic inhibitor/carbapenem combinations allow us to visualize the efficacy of carbapenemase inhibitors. The in vitro results are consistent with clinical experience regarding combination therapy. Enzymatic assays provide a rapid yes/no answer for carbapenem mono- or combination therapy and offer several advantages over current carbapenemase testing methods. In contrast to PCR and lateral flow tests, which only target a selection of carbapenemases, enzymatic assays work by employing a reproducible phenotypic mechanism. They are simpler, broader in scope, and more cost-effective; they can also detect antimicrobial heteroresistance or AmpC beta-lactamase hyperproduction, which is normally undetected when performing automated antibiotic susceptibility testing. The new tests are suitable for clinical diagnosis, public health purposes, and infection control. Full article

Background: Due to the wide host range of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), vaccination has been recommended for susceptible species in zoological collections, particularly to protect endangered species. The Zoetis^® Experimental Mink Coronavirus Vaccine (Subunit) was temporarily authorized in 2021–2024 for emergency use in North America for this purpose. However, there are limited data regarding its safety or efficacy in non-domestic mammals. The present study was conducted to assess the ability of this vaccine to elicit serum neutralizing titers against SARS-CoV-2 in selected animals from the Toronto Zoo (TZ) vaccinated during 2022. Methods: Serum samples were collected from 24 individuals across four families (Cervidae, Felidae, Ursidae, and Hyaenidae) and tested using a surrogate virus neutralization test (sVNT) and a plaque-reduction neutralization test (PRNT). Results: The results showed that all species developed some neutralizing titers after at least one vaccine dose, except for polar bears, which showed no seroconversion. Felids and hyenas had the highest neutralizing titers, which peaked at 3 and declined between 4 and 6 months after boost. These differences may stem from species-specific immune responses or lack of vaccination protocols tailored to individual species. Conclusions: While natural infection with SARS-CoV-2 could not be ruled out in the cohort of this study, insights from our results have the potential to inform future vaccine recommendations for non-domestic species. Furthermore, our study highlighted the value of competitive assays in assessing serological responses across a broad range of exotic species, for which reagents, such as anti-isotype antibodies, are often unavailable. Full article

Avian genome editing has historically lagged behind mammalian research. This disparity is primarily due to a unique reproductive biology that precludes standard techniques like pronuclear injection. A pivotal breakthrough, however, came from the development of efficient in vitro culture systems for primordial germ cells (PGCs). This has established the chicken as a tractable and powerful model for genetic engineering. Our review chronicles the technological evolution this has enabled, from early untargeted methods to the precision of modern CRISPR-based systems. We then analyze the broad applications of these tools, which are now used to engineer disease resistance, enhance agricultural traits, and develop novel platforms such as surrogate hosts and oviduct bioreactors. Collectively, these advances have established PGC-based genome editing as a robust and versatile platform. Looking forward, emerging precision editors and the expansion of these techniques to other avian species are poised to drive the next wave of innovation in poultry science and biotechnology. Full article

Background/Objectives: Ethnopharmacological studies indicates that plant-based infusions are usually consumed by some people in advanced stages of diabetes, that is, when poor pancreatic dysfunction coexists with insulin resistance (IR). Current treatments aim to prevent β-cell deterioration by promoting improved insulin function and/or enhancing pancreatic function to avoid the development of hyperglycemia. Therefore, Croton guatemalensis (Cg) and Eryngium cymosum (Ec), two medicinal plants with potential insulin-sensitizing effects described in previous studies, were assessed on parameters related to IR and on the architecture of pancreatic islets in rats exposed to a syrup containing 8.8% glucose and 5.2% fructose in drinking water. Methods: After an 8-week exposure to syrup, plant extracts were orally administered for four weeks at traditional doses (Cg: 30 mg/kg body weight; Ec: 470 mg/kg body weight). Body weight, food intake, and drinking water consumption were monitored. At the end of the study, IR surrogate indices were calculated, metabolic assays were performed, and white adipose tissues, liver, gastrocnemius muscle, and pancreas were extracted in fasting and postprandial state for lipid quantification (liver), measurement of Akt phosphorylation status by western blot (liver and muscle), and determination of insulin content by immunohistochemistry (pancreatic islets). Results: Both species decreased hepatic lipid content without promoting significant changes in visceral adiposity. Although they did not improve surrogate markers of fasting IR, both ameliorated insulin function, glucose tolerance, and restored the glucose-stimulated insulin secretory response in metabolic tests. Cg restored the insulin signaling response in liver and muscle, whereas Ec only did so in muscle. Moreover, both appeared to enhance insulin pancreatic content or restore pancreatic islet population. Conclusions: Cg and Ec can reverse the IR phenotype in a tissue-specific manner and improve pancreatic function. Full article

Myalgic Encephalomyelitis (ME) is a complex, multisystem disorder with poorly understood pathophysiological mechanisms. SMPDL3B, a membrane-associated protein expressed in renal podocytes, is essential for lipid raft integrity and glomerular barrier function. We hypothesize that reduced membrane-bound SMPDL3B may contribute to podocyte dysfunction and impaired renal physiology in ME. To investigate this, we quantified soluble SMPDL3B in plasma and urine as a surrogate marker of membrane-bound SMPDL3B status and assessed renal clearance and plasma metabolomic profiles. In a cross-sectional study of 56 ME patients and 16 matched healthy controls, ME patients exhibited significantly lower urine-to-plasma ratios of soluble SMPDL3B and reduced renal clearance, suggesting podocyte-related abnormalities. Plasma metabolomics revealed dysregulation of metabolites associated with renal impairment, including succinic acid, benzoic acid, phenyllactic acid, 1,5-anhydroglucitol, histidine, and citrate. In ME patients, plasma SMPDL3B levels inversely correlated with 1,5-anhydroglucitol concentrations and renal clearance. Multivariable modeling identified the urine-to-plasma SMPDL3B ratio as an independent predictor of clearance. Female ME patients showed more pronounced SMPDL3B alterations, reduced clearance, and greater symptom severity. Non-linear associations between soluble SMPDL3B and lipid species further suggest systemic metabolic remodeling. These findings support soluble SMPDL3B as a potential non-invasive biomarker of renal-podocyte involvement in ME, highlighting sex-specific differences that may inform future therapeutic strategies. Full article

The Brazilian Atlantic Forest is currently reduced to a few, small fragments surrounded by anthropic landscapes. Urban forest remnants play an important role in housing biodiversity in urbanized areas and enabling species dispersion between larger natural areas. Describing and monitoring the biodiversity in these anthropized environments is a useful tool for urban ecology and species conservation. By compiling long-term data, this study proposes a species list of tropical diurnal butterflies for an Atlantic Forest remnant in Southeastern Brazil and describes the temporal diversity patterns of the community. Inventories were carried out from the 1970s to 2000 to record butterfly incidence data in a 250 ha fragment of seasonal, semideciduous Atlantic Forest, resulting in a species list of 706 species presented here for the first time for the studied area. From 1998 to 2000, weekly standardized observations enabled inferences on temporal trends in butterfly diversity. Total species richness peaked in the climatic transitions, and a cycle of 52 weeks was reported for beta diversity. Butterfly families lack synchronized temporal fluctuations. Nymphalidae and specifically the fruit-feeding nymphalids were considered good surrogates for short-term studies and monitoring community changes. Full article

Reduced chemical kinetic mechanisms are essential for enabling the use of complex fuels in 3D CFD combustion simulations. This study presents the development and optimization of a compact mechanism capable of accurately modeling ethanol–gasoline blends, including Brazilian Type-C gasoline (27% ethanol by volume) and up to pure ethanol (E100). An initial mechanism was constructed using the Directed Relation Graph with Error Propagation (DRGEP) method applied to detailed mechanisms selected for each surrogate component. The resulting mechanism was then refined through three global iterations of a genetic algorithm targeting ignition delay time (IDT) and laminar flame speed (LFS) performance. Five candidate versions (Mec1 to Mec5), each containing 179 species and 771 reactions, were generated. Mec4 was identified as the optimal configuration based on quantitative error analysis across all tested conditions and blend ratios. The final mechanism offers a balance between predictive accuracy and computational feasibility, making it well-suited for high-fidelity simulations in complex geometries involving multi-component ethanol–gasoline fuels. Full article