National University of Salta

The rapid development of effective vaccines, particularly for diseases lacking prophylactic options, remains a critical global health priority. Among these, Chagas disease, caused by the intracellular parasite Trypanosoma cruzi, still has no approved vaccine despite decades of research. Conventional platforms often face limitations in terms of scalability, safety, or immunogenicity, especially when targeting complex parasitic infections. Although Lactobacillus acidophilus has been explored as a probiotic vector, its use in customizable vaccine platforms remains underdeveloped. Here, we evaluated the potential of SlpA, the major surface-layer (S-layer) protein of L. acidophilus, as a structurally stable and immunostimulatory scaffold for antigen presentation. Specifically, we assessed its performance when fused to Tc52, a well-characterized T. cruzi antigen associated with partial protection. We engineered a biosafe, recombinant-free system where purified N-Tc52/SlpA fusion protein and SlpA-coated probiotic bacteria were tested for protective efficacy. The N-Tc52/SlpA fusion consistently enhanced both the magnitude and quality of antibody responses, inducing balanced IgG2c/IgG1 ratios. Upon challenge, animals receiving N-Tc52/SlpA, either in purified form or displayed on L. acidophilus, exhibited reductions in parasite burden in heart and skeletal muscle tissues. Cellular analyses further revealed that both formats promoted activation of splenic CD4+ and CD8+ T cells and expansion of effector and central memory CD4+ subsets, highlighting SlpA's ability to sustain T cell responses. These findings position SlpA as a dual-purpose macromolecule, functioning as both antigen carrier and immunostimulant, and establish a proof of concept for SlpA-based delivery systems adaptable to other intracellular pathogens, particularly where affordability, safety, and stability are crucial.

Reconstructing facies architecture in ancient volcano-sedimentary successions is often challenging due to incomplete exposure, deformation, metamorphism, and hydrothermal alteration. The Alemania Subbasin (Salta, Argentina) preserves exceptionally well both sedimentary and volcanic successions, which are exposed as subvolcanic and volcanic units due to tectonic activity. The Cretaceous northwestern basins of Argentina are interpreted as an aborted retroarc rift, comprising interconnected grabens that converge at a triple junction with a central horst (Salta-Jujuy horst). The Alemania Subbasin contains thick sedimentary-volcanic successions of the Salta Group, including the Pirgua, Balbuena, and Santa Barbara subgroups. The Pirgua Subgroup consists of continental red beds deposited during the syn-rift stage, with volcanic activity primarily recorded by the Las Conchas Basalt (78-77 Ma) in the upper part of the succession (Las Curtiembres Formation). This study focuses on outcrops along Las Conchas Canyon, where both coherent volcanic facies (lava flows, pillow lavas, dykes) and volcaniclastic facies (diatreme breccias, pyroclastic surge deposits, peperites, sediment-infill volcanic breccias, and lahars) interbed with fluvial red beds. Variations in facies architecture reflect contrasting eruptive styles, likely controlled by changes in environmental hydrology and magma-water interaction processes. The Las Conchas Basalt records both hydromagmatic and effusive eruptions. Volcanic architecture reconstruction allowed the identification of facies corresponding to upper and lower diatreme deposits, dykes, and lava flows, associated with peperites and sediment-infill volcanic breccias. Subvolcanic units were likely emplaced in a meandering fluvial paleoenvironment, whereas lava flows advanced across sandy braided fluvial systems under semi-arid conditions. Pillow lavas within lacustrine host rocks (Morales Members) indicate local water bodies sufficient for non-explosive magma-water interactions. Changes in water availability and environmental conditions likely explain the transition from hydromagmatic to effusive eruptive styles, despite the magma remaining basanitic. This study demonstrates that paleoenvironmental and hydrological conditions strongly influenced facies development in monogenetic volcanic fields and provides insights into reconstructing ancient volcano-sedimentary systems in rift-related basins.

Phase change materials (PCMs) are a promising passive technology for reducing building heating and cooling energy use, yet their whole-building effectiveness as latent thermal storage remains insufficiently characterized. The present study introduces PCM Effectiveness Indicators (PCMEIs), a set of physics-informed, whole-building metrics that relate daily thermal-load reductions to the installed latent heat capacity. Using these indicators, this study demonstrates that PCM activation is a necessary but not sufficient condition for whole-building effectiveness. The proposed indicators capture dynamic, year-round performance across climates, implicitly accounting for partial phase transitions, fluctuating loads, and interactions with passive design strategies. They can be applied consistently to heating, cooling, and mixed-load analyses. Using EnergyPlus simulations and a global sensitivity analysis, 400 design configurations were evaluated for a prototype building in four ASHRAE climate zones (3A, 4A, 5A, and 6A). Across all climates, envelope characteristics, particularly the window-to-wall ratio, exerted a stronger influence on PCM effectiveness than commonly studied material properties such as melting temperature. These findings highlight the importance of co-optimizing PCMs with envelope design variables, especially at early design stages. Furthermore, PCMs achieved the highest effectiveness in heating-dominated climates and when mitigating cooling loads. Despite substantial PCM-induced load reductions, PCMEI values rarely exceeded 20%, indicating practical limits to whole-building latent-capacity utilization under real climatic variability. A design threshold was identified: maintaining installed latent heat capacity below approximately twice the building’s peak daily thermal load prevents oversizing and maximizes utilization. The proposed PCMEIs provide a transparent and scalable framework for whole-building evaluation of PCMs, supporting benchmark development and performance-based integration in energy-efficient building design.

Se presentan los resultados de las investigaciones realizadas en Cafayate y en la Reserva Natural Quebrada de las Conchas (Salta), enmarcadas en el registro y revisión sistemática de sitios arqueológicos y en la actualización de la carta arqueológica local. En este contexto, el objetivo principal de este artículo es construir mapas temáticos de sensibilidad arqueológica basados en Sistemas de Información Geográfica (SIG) para evaluar e identificar factores de riesgo, tanto naturales como antrópicos, que impactan sobre la conservación del patrimonio en el área. Actualmente se registraron 61 sitios con cronologías que van desde el Período Formativo, Desarrollos Regionales, Inca e Hispano-Indígena. Para evaluar los estados de conservación e identificar factores de riesgo se ha trabajado con el uso de Vehículos Aéreos No Tripulados (VANT) para el relevamiento fotogramétrico de arquitectura y paneles con arte rupestre. La integración de estos productos digitales en un entorno de Sistemas de Información Geográfica (SIG) permitió generar planimetrías de detalle y modelos de elevación digital para la confección de mapas temáticos de sensibilidad arqueológica. A partir de dos casos piloto, Molino de Piedra y Ruinas de Quitilípi, se observa que el municipio de Cafayate evidencia una alta vulnerabilidad ante impactos antrópicos vinculados al avance inmobiliario y vitivinícola, mientras que en la Quebrada de las Conchas predominan riesgos de origen natural mitigados por la protección de la reserva y la custodia de las comunidades Diaguitas. Estas herramientas funcionan como respaldo técnico ante demandas de ordenamiento territorial concretas, utilizándose para la elaboración de proyectos de ordenanza municipal y circuitos de monitoreo junto a los guardaparques provinciales. Como tareas a futuro, la agenda plantea el desafío de complejizar la evaluación de riesgos mediante la colaboración interdisciplinaria y el diálogo horizontal con los actores sociales del territorio.

Las pasturas implantadas en el Chaco Semiárido están conformadas principalmente por especies con metabolismo carbono 4 (C4), cuyo crecimiento ocurre de manera estacional y en forma de pulsos, entendidos como patrones de crecimiento y desarrollo asociados a fluctuaciones ambientales cíclicas. En estos sistemas, la vegetación presenta períodos de crecimiento acelerado durante condiciones favorables, principalmente vinculadas a la disponibilidad hídrica y la temperatura, y una marcada reducción o interrupción del crecimiento durante etapas desfavorables. En consecuencia, la producción forrajera disminuye significativamente al inicio del verano y durante el otoño debido al déficit hídrico, las bajas temperaturas, las heladas y la escasa precipitación, generando un período crítico de disponibilidad forrajera desde fines del invierno hasta comienzos de la primavera. La ganadería pastoril de la región se sustenta mayoritariamente en monocultivos de Megathyrsus maximus cv. Gatton Panic, lo que incrementa la vulnerabilidad del sistema frente a la variabilidad ambiental. En este contexto, la diversificación mediante la incorporación de especies con diferentes atributos productivos y de manejo podría contribuir a estabilizar la oferta forrajera y reducir riesgos productivos. La presente revisión sistematiza información sobre la morfología, los requerimientos edafoclimáticos, el manejo, la productividad y la calidad forrajera de Chloris gayana Kunth (grama rhodes) y Urochloa ruziziensis (pasto ruzi, pasto congo; sin. Brachiaria ruziziensis), con un enfoque comparativo que permita analizar su potencial para ser asociadas entre sí. Finalmente, se destaca la necesidad de avanzar en ensayos experimentales que permitan evaluar la productividad, la calidad forrajera y la competencia interespecífica de estas especies en distintas proporciones.