DSpace Comunidad :

Is mineral nutrient concentration of soybean, maize, and wheat grain affected by cropping sequence and agronomic management?

2026-09-29T07:01:24Z

Título: Is mineral nutrient concentration of soybean, maize, and wheat grain affected by cropping sequence and agronomic management? Autor: Becheran, D. E.; Miguez, F. H.; Miguez, F. E.M; Peper, A.; Benedit, B. Resumen: Producers in the Argentine Pampas often fail to fully replenish the nutrients extracted by crops, leading to unsustainable soil fertility management. The objectives of this study were to (i) evaluate grain yield, mineral nutrient concentration, and extraction for maize (Zea mays L.), wheat (Triticum aestivum L.), and soybean (Glycine max L. Merr.) under contrasting agronomic management systems and (ii) compare mineral nutrient concentration with nutrient removal values commonly used as reference in Argentina when assessing crop nutrient soil uptake. The study was conducted over 8 years in a field experiment located in the central Rolling Pampas, under three crop sequences: continuous soybean (Sy), a 2-year rotation alternating maize and soybean (Mz–Sy), and a 3-year rotation including wheat/soybean double crop, maize, and soybean (Wt/SyDC–Mz–Sy). In addition, these were evaluated with either fallow or winter cover crops (CCs) present under two agronomic systems: conventional management (CM) and intensified management (IM). The IM system included different genotypes, plant densities, fertilizer types, and rates. The IM increased yield for Mz by 1.25 Mg ha−1 (p < 0.01), Wt by 0.82 Mg ha−1 (p < 0.05), Sy1 (soybean full season crop) by 0.28 Mg ha−1 (p < 0.05), and SyDC by 0.39 Mg ha−1 (p < 0.05). The inclusion of a CC decreased yield for Mz by 1.20 Mg ha−1 (p < 0.01) and Sy1 by 0.34 Mg ha−1 (p < 0.05), only within CM and in the drier years. The IM increased nitrogen (N) and sulfur (S) concentrations for Sy but had no consistent effects on nutrient concentrations in other crops. Observed grain nutrient concentration values, despite their variability, could be used to estimate nutrient exports by these crops.

Valorisation of quinoa scarification residues: impact of desaponification methods on functional and emulsifying properties

2026-06-27T07:01:14Z

Título: Valorisation of quinoa scarification residues: impact of desaponification methods on functional and emulsifying properties Autor: Ragonese, Verónica E.; Moscoso Ospina, Yeisson A.; Cabezas, Darío M.; Kakisu, Emiliano J. Resumen: BACKGROUND: Quinoa is widely recognised for the high biological value of its proteins. However, its outer layer contains saponins, an antinutrient that must be removed for consumption. The process of dry desaponification of grains is known as scarification and produces a residual powder that is usually discarded. RESULTS: The quinoa scarification residue (QSR) contained 5 g kg−1 of saponins. Thus, washing with water, homogenisationassisted washing (HQSR) and sonication-assisted washing (SQSR) methods were evaluated. The assisted washing methods used 50% less water, although all of them reduced the residual saponin content (∼0.5 g kg−1 ) and significantly concentrated the protein content of the samples (∼270–290 g kg−1 ), compared to the control sample (∼210 g kg−1 ). The electrophoretic profile in sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed the presence of the structural protein chenopodin, with its acidic (30–40 kDa) and basic (20–25 kDa) subunits, as well as protein macromolecules higher than 100 kDa. Fragmented particles were also observed in the HQSR and SQSR samples using low-vacuum scanning electron microscopy, although the latter also presented porous structures. Both a decrease in oil/water interfacial tension – mainly in HQSR (19.22 mN m−1 ) − and a significant increase in interfacial viscosity in SQSR (1.5 E−5 Pa s) were observed. Emulsions formulated with the sonicated sample showed greater stability against coalescence, creaming and sedimentation processes. CONCLUSION: Ultrasound-assisted desaponification proved to be efficient, improving the functional characteristics of this residue and opening new possibilities for its use in food systems.

Epanechnikov Nonparametric Kernel Density Estimation Based Feature-Learning in Respiratory Disease Chest X-Ray Images

2026-06-27T07:01:15Z

Título: Epanechnikov Nonparametric Kernel Density Estimation Based Feature-Learning in Respiratory Disease Chest X-Ray Images Autor: Marsico, Verónica; Quintero-Rincón, Antonio; Batatia, Hadj Resumen: This study presents a novel method for diagnosing respiratory diseases using image data. It combines Epanechnikov’s nonparametric kernel density estimation (EKDE) with a bimodal logistic regression classifier in a statistical-model-based learning scheme. EKDE’s flexibility in modeling data distributions without assuming specific shapes and its adaptability to pixel intensity variations make it valuable for extracting key features from medical images. The method was tested on 13808 randomly selected chest X-rays from the COVID19 Radiography Dataset, achieved an accuracy of 70.14%, a sensitivity of 59.26%, and a specificity of 74.18%, demonstrating moderate performance in detecting respiratory disease while showing room for improvement in sensitivity. While clinical expertise remains essential for further refining the model, this study highlights the potential of EKDE-based approaches to enhance diagnostic accuracy and reliability in medical imaging.

Eugenol exposure during gravid and non-gravid periods in the fish Cnesterodon decemmaculatus: effects on anesthesia, acetylcholinesterase activity, and parasitic response

2026-06-27T07:01:08Z

Título: Eugenol exposure during gravid and non-gravid periods in the fish Cnesterodon decemmaculatus: effects on anesthesia, acetylcholinesterase activity, and parasitic response Autor: Vercellini, María Clara; Carranza Martin, Ana Cristina; Ruiz de Arcaute, Celeste; Soloneski, Sonia; Ayala, Mauro Alejandro Resumen: Eugenol is a widely used plant-based anesthetic in aquaculture. However, its anticholinesterase activity may affect reproductive physiology, particularly in gravid females. This study examined the effects of eugenol on the anesthetic response, acetylcholinesterase (AChE) activity, and parasite abundance in wild-caught adult females of the Neotropical fish Cnesterodon decemmaculatus. Ninety females were exposed to five eugenol concentrations (10, 20, 30, 40, and 50 mgL⁻1), and a control group without anesthetic. Anesthesia induction and recovery times were recorded, and AChE activity was estimated in gravid females. Induction time decreased with increasing eugenol concentration up to 40 mgL⁻1, with no further reduction at 50 mgL⁻1. Recovery times did not differ significantly among treatments. AChE activity was significantly inhibited, and both abortion and mortality were observed in gravid females exposed to 10 mgL−1. Additionally, a reduction in the mean abundance of the Eschistostomatidae family was detected only after the 40 mgL⁻1 treatment, in all treated specimens. These findings highlight the physiological vulnerability of gravid females to eugenol exposure and suggest a potential antiparasitic effect at specific concentrations. The results emphasise the importance of considering reproductive status when assessing anesthetic safety in ovoviviparous fish.