国立滨海大学

Controlled traffic farming (CTF) confines soil compaction to permanent traffic lanes (PTL), potentially improving soil physical quality and crop production in permanent crop beds (PCB). This study evaluated the effects of CTF on soil physical quality and crop yield in Typic Argiudolls of Santa Fe Province, Argentina, over a six-year period. On-farm experiments were conducted under no-tillage and CTF at Aurelia and Videla. Three compaction levels were imposed on PTL at the beginning of the experiment: minimal (T0), moderate (T1), and high (T2) compaction, arranged in a randomized complete block design with three replicates, while PCB remained compaction-free. Compaction in T1 and T2 was generated by multiple combine harvester passes. Undisturbed soil samples were collected from PTL and PCB at the 0–20 cm depth in years 0, 3, and 6 to determine soil water retention, penetration resistance, effective stress, least limiting water range (LLWR), and relative compaction (RC). Soybean and maize yields were measured, and the relationship between relative crop yield and RC was evaluated using boundary-line analysis. Soil properties varied across treatments and years. Penetration resistance, effective stress, and RC were consistently lower in PCB than in PTL. The LLWR declined sharply when RC exceeded 88%, mainly due to increased penetration resistance and reduced air-filled porosity. Relative crop yield also decreased sharply when RC exceeded 88%. The convergence of LLWR limitations and yield responses around the same RC threshold indicates that RC is a robust integrative indicator linking soil physical quality and crop production in no-tillage, CTF systems.

Trypanosoma cruzi (T. cruzi), the protozoan parasite that causes Chagas disease, remains a major public health challenge, with more than six million people infected worldwide. Despite more than a century of research and extensive evaluation of different strategies, no vaccine has progressed to late-phase clinical trials. This failure highlights the need to better understand host–parasite interactions, with special emphasis on the immunoregulatory pathways exploited by the parasite. In this review, we propose an initial comprehensive map of the T. cruzi immune manipulation network, integrating research on numerous parasite and host components involved. Five main cores of manipulation are proposed, including how T. cruzi skews macrophage polarization toward regulatory profiles, the impairment of dendritic cell maturation and Th1 induction, resistance to and subversion of complement pathways, expansion of myeloid-derived suppressor cells (MDSCs), and suppression and delay of adaptive immunity by driving non-specific B-cell activation, thymic atrophy, and T-cell dysfunction. Mapping these mechanisms may reveal how parasite molecules such as trans-sialidases, cruzipain, proline racemase, mucin-associated surface proteins, complement regulatory proteins, and others interact in a complex network of manipulated immune pathways. A deeper understanding of these interactions could have significant implications for immunotherapeutic strategies. Future vaccine designs may benefit from rationally selected combinations that maximize targeted effector responses while minimizing the manipulation of the immune network by T. cruzi.

IntroductionThe growing demand for plant-based functional foods has driven research into non-dairy fermented alternatives that can deliver live microorganisms and potential health benefits. The pseudocereal Quinoa is a substrate of interest for lactic acid fermentation. This study aimed to develop a fermented quinoa-based beverage using autochthonous lactic acid bacteria (LAB) strains with technological and functional potential.MethodsSix LAB strains previously isolated from plant sources were screened for growth kinetics in an animal-free medium and in quinoa extract (QE). Lactiplantibacillus plantarum LpAv and Limosilactobacillus fermentum Lf2, an exopolysaccharide (EPS)-producing strain, were selected for beverage development. Fermentation parameters, rheological and biochemical profiles, peptide release, and sensory attributes were evaluated. An animal trial assessed immunomodulatory and antioxidant capacity in BALB/c mice that received fermented QE.ResultsBoth strains were able to acidify QE to pH < 4.5 within 8 h, ensuring microbiological safety. EPS production by Lf2 improved viscosity and texture, while mixed fermentation enhanced lactic acid yield and impacted on peptidic profiles, indicating synergistic proteolytic activity. LAB remained viable (>8 log CFU/mL) after 28 days at 4 °C. Sensory testing (n = 111 participants) showed moderate acceptability, improved by artificial flavoring. In mice, fermented QE increased intestinal IL-10 and IFN-γ levels and elevated hepatic catalase and superoxide dismutase activities, suggesting antioxidant and immune-modulatory effects without bacterial translocation.ConclusionThis work demonstrates the feasibility of producing a safe, stable, and functionally active fermented quinoa beverage using locally sourced LAB. The combination of L. plantarum LpAv and L. fermentum Lf2 improved both technological and functional properties, supporting their potential as starter cultures for plant-based probiotic foods.

Modularity and nestedness have been observed recurrently across different ecological networks, including food webs and occurrence networks. These patterns emerge from species-level processes, where interactions and occurrences are determined by niche-based and/or abundance-based mechanisms. Abundance-based processes promote nested networks with gradients in the number of links determined by species abundances. Niche-based processes can promote modular structures due to differential spatial filters or trait matching in discontinuous gradients of predators and prey traits or nestedness due to gradients in the strength of environmental filters or trait limitation for consumption. Here, we explore the mechanisms driving species-level interactions and the resulting network structure in both food webs and occurrence networks of piscivorous fishes from the Paraná River. Our study focused on 16 species of piscivorous fish. We constructed occurrence networks (149 communities, 3010 observations) and food webs (113 prey species, 1271 trophic interactions). Using null models, we assessed modularity and nestedness in both types of networks, as well as the existence of significant deviations in the trait composition, functional diversity and community-weighted mean among modules. Moreover, we assessed the relationship between species abundance and degree to identify the potential role of abundance-based processes. Occurrence networks and food webs exhibited a modular structure, with no evidence of nestedness. In both networks, niche-based mechanisms played an important role. Each module showed a distinct representation of habitat types in occurrence networks and prey types in food webs. A significant relationship was also observed between predator abundance and the number of interactions or occurrences, suggesting that abundance-based mechanisms also contribute to network organization. Here, we are getting ahead in understanding the mechanisms driving ecological organization in piscivorous fishes from the Middle Paraná River. Although food webs and occurrence networks represent distinct dimensions, our results reveal a consistent pattern: both are shaped by a combination of abundance- and niche-based processes. This convergence highlights shared principles of network assembly across contexts. By disentangling the contributions of these mechanisms, our findings advance ecological theory and highlight that protecting functional diversity and resource heterogeneity is essential for preserving the structure of ecological networks.

Activated sludge systems are widely used for the treatment of effluents with high organic loads. In this study, tannery effluents were treated through bioaugmentation with activated sludge under mesocosm conditions. After 10 days of treatment, significant removal efficiencies were achieved for key physicochemical parameters, including COD (80