Abstract This study investigates the hydrodynamic and sediment-transport dynamics during a flash flood that occurred on February 23, 2024, in the San Antonio River, a tributary of the San Roque Reservoir in Córdoba, Argentina. Such events pose a significant hazard in urban and recreational rivers; however, their transient processes remain poorly understood, particularly regarding the onset of bed-load transport and the vulnerability of exposed individuals. High-resolution, stationary measurements were collected using an Acoustic Doppler Current Profiler (ADCP), generating time series of flow depth, velocity, and energy slope during the passage of the flood wave front. Sediment mobilization was assessed through the Shields–Parker diagram, and flow conditions were compared against human body stability criteria for both adults and children. Results indicate that the velocity rise preceded the increase in flow depth, reflecting an initial adjustment of the wave-front slope. During the flood arrival, during a 22-min interval, flow depth increased from 0.40 to 1.47 m, and velocity rose from 0.20 to 2.00 m / s . Bed-load transport initiated given higher velocities with nearly constant depth, followed by sustained transport and a sharp increase in suspended sediment presence. Regarding human safety, the applied body stability criteria indicate that instability thresholds were exceeded rapidly: within only 2 min for children and 3 min for adults after the onset of the rising limb, highlighting the high vulnerability of recreational areas. These findings emphasize the value of direct, high-resolution observations to better understand unsteady processes in flash floods and to provide key insights for risk management in urban and touristic river systems.
Available evidence reveals marked disparities in how invasive trees affect soil organisms, including fungi, however whether these patterns mirror aboveground biodiversity responses remains unclear. Moreover, the impacts of many woody invaders on soil fungal communities are still unknown. In this study, we examined the effects of the invasive tree Ligustrum lucidum on soil fungal communities in forests of central Argentina using ITS rDNA metabarcoding. Specifically, we evaluated taxonomic and functional group (guild) fungal diversity and community composition in monodominant stands of invasive L. lucidum compared with native forests. To this end, we selected six areas with paired native and invaded forests and collected five soil samples in each. L. lucidum invasion promoted higher taxonomic and functional richness, as well as shifts in richness and relative abundance at guilds level. This pattern was mainly explained by increases in certain saprotrophic guilds, including litter, wood, and dung saprotrophs, and the biotrophic guild of mycoparasites. In contrast, the biotrophic guilds of animal parasites and plant pathogens showed reduced abundance in invaded forests. Fungal community composition across guilds differed between invaded and non-invaded forests. The effects on saprotrophic fungi may be related to traits of the invasive plant, probably belowground traits, and associated changes in soil properties, whereas for biotrophic fungi, changes in host diversity and abundance may play a more important role. Our results demonstrate that L. lucidum substantially alters soil fungal communities at both taxonomic and functional levels, potentially leading to important consequences for ecosystem processes in invaded forests.
This study evaluates the techno-economic and environmental performance of electricity generation from agricultural residues in Las Colonias Department, Santa Fe Province, Argentina, using the System Advisor Model (SAM). Wheat straw, corn stover, soybean residues, sunflower residues, and sorghum residues were quantified from regional crop production. A conservative 10% obtainability factor resulted in 79,490 dry short tons/y (72,112 metric dry t/y) of available biomass and a modeled plant capacity of approximately 11.86 MW. The fed-as-received configuration generated 85.31 GWh/y at an 82.10% capacity factor and 25.35% HHV thermal efficiency. Under a USD-denominated financial model with a 10% real discount rate, 4% inflation, and a first-year electricity selling price of 0.118 USD/kWh, the project yielded a real LCOE of 0.0855 USD/kWh, an NPV of USD 6.82 million, and an IRR of 19.75%. Active drying to 10% moisture slightly increased electricity generation but reduced NPV to USD 5.65 million and increased the lifecycle burden associated with fuel conditioning. Stochastic uncertainty analysis showed that 92.0% of the evaluated cases resulted in a positive NPV, while electricity selling price and inflation were the main drivers of project profitability. Environmental results, based on SAM's generic biomass life-cycle accounting rather than crop-specific upstream agricultural inventories, were interpreted as screening-level indicators rather than as a fully regionalized LCA or evidence of permanent carbon removal. Overall, agricultural-residue electricity generation appears technically feasible and economically attractive under the evaluated conditions, although feedstock quality, ash behavior, storage, soil nutrient replacement, and market conditions remain important project-specific uncertainties.
Dried blood spot (DBS) technology is an expanding tool for trace element determination; however, quantification by X-ray fluorescence (XRF) faces challenges due to matrix effects, surface irregularities, and blood volume variability. This paper presents a novel methodology for the quantitative determination of lead (Pb) in DBS samples using Secondary Target Energy-Dispersive X-ray Fluorescence Spectroscopy (ST-EDXRF). Potassium (K) was employed as an internal reference to compensate for hematocrit variability. A Mo X-ray tube equipped with interchangeable secondary targets was used: vanadium (V) to excite K and strontium chloride (SrCl2) to optimize excitation of the Pb-L alpha line. Normalization strategies were implemented to minimize the effects of sample volume variations and surface roughness: K intensities were normalized to the atmospheric Ar-K alpha line, whereas Pb intensities were normalized to the incoherent scattering peak. These normalization procedures significantly improved analytical performance, increasing the coefficients of determination (R2) of the calibration curves to 0.996 for K and 0.999 for Pb. A detection limit of 0.04 ppm (w/w) Pb in blood was achieved with a 15 min acquisition time, comparable to that of state-of-the-art commercial EDXRF systems. As a preliminary evaluation, the methodology was applied to a single DBS prepared from venous blood collected from a healthy volunteer. Pb was not detected, as expected, whereas K was successfully quantified within the physiological range. In addition, the method accurately quantified Pb in an artificially spiked blood sample, demonstrating its capability for quantitative analysis. The developed ST-EDXRF approach effectively compensates for substrate irregularities, sample volume variations, and hematocrit effects, providing a low-cost and sensitive methodology suitable for field monitoring of populations at risk of lead exposure.
In the field of vaccines, adjuvants have been optimized to enhance immune responses while reducing adverse effects. Transferring these advances to antivenom production could improve antibody quality and animal welfare. Here, we evaluated a novel adjuvant platform, CpG-ODN/Coa-ASC16, which combines immunostimulatory CpG-ODN oligodeoxynucleotides with the biodegradable nanostructure Coa-ASC16, co-formulated with a hemorrhagic antigenic model based on Bothrops diporus venom (B.dV). Immunization with B.dV/CpG-ODN/Coa-ASC16 elicited IgG titers equivalent to those induced by Freund’s adjuvant, with significantly higher IgG1 levels. Antibodies generated with both formulations exhibited progressively higher avidity, reflecting effective affinity maturation. Sera from B.dV/CpG-ODN/Coa-ASC16-immunized mice recognized major venom proteins and neutralized key toxic activities—proteolytic, coagulant, and indirect hemolytic—at levels comparable to Freund’s-induced sera. Functionally, sera from B.dV/CpG-ODN/Coa-ASC16-immunized mice conferred protection against a lethal venom challenge, resulting in survival of a fraction of animals and prolonged time to death in non-survivors. Importantly, histopathological analyses revealed minimal tissue alterations in the mice treated with CpG-ODN/Coa-ASC16, in sharp contrast to the severe abscesses and granulomas caused by Freund’s adjuvant. Overall, this study provides new evidence that CpG-ODN/Coa-ASC16 can be effectively combined with hemorrhagic Bothrops venom to generate robust, high-affinity antibodies that efficiently neutralize the major venom toxins while markedly reducing local tissue damage. These findings position CpG-ODN/Coa-ASC16 as a safer and ethical alternative platform for antivenom production.
